WO2023068919A1

WO2023068919A1 - Energy and power management system for demand and supply of renewable energy in a nanogrid and a method thereof

Info

Publication number: WO2023068919A1
Application number: PCT/MY2021/050109
Authority: WO
Inventors: Nadia TAN MEI LIN; Mohd. Zafri BIN BAHARUDDIN; Yasir Sabah DIRA
Original assignee: Nanomalaysia Berhad; UNIVERSITI TENAGA NASIONAL
Current assignee: Nanomalaysia Berhad; UNIVERSITI TENAGA NASIONAL
Priority date: 2021-10-18
Filing date: 2021-11-25
Publication date: 2023-04-27
Anticipated expiration: 2024-04-18
Also published as: MY201012A

Abstract

The present invention provides an energy and power management system for managing, harvesting, storing and discharging of electrical power to ensure demand and supply of renewable energy to an anergy load and a method thereof. The energy and power management system comprising: a grid linked to a plurality of meters; a plurality of nanogrid panels comprising an MPPT module system; a plurality of energy storage devices that work in communication with the plurality of nanogrid panels; and a main meter for measuring and displying input and output of renewable energy power to the energy load. The present invention provides for an efficient and homogenous charging and discharging system for an extended battery lifecycle. The methodology of the present invention particularly the control philosophy of the energy and power management system is described in three modes.

Description

ENERGY AND POWER MANAGEMENT SYSTEM FOR DEMAND AND SUPPLY OF RENEWABLE ENERGY IN A NANOGRID AND A METHOD THEREOF

FIELD OF INVENTION

The present invention relates to an energy and power management system to ensure demand and supply of renewable energy to an energy load and a method thereof. In particular, the present invention provides an energy and power management system comprising a nanogrid and an energy storage system made up of batterries and a supercapacitor.

BACKGROUND ART

In recent years, renewable energy and the means of power distribution to meet load demands have been researched to find alternatives and a more environmental friendly approach of power generation and supply. The use of microgrids comprising distributed renewable resources, distributed storage units and load are found to enhance stability and reliability of power grids and make conventional power grids suitable for distributed renewable generation. This microgrid concept can be used in residences and small buildings with smaller rated power and modularity. This is commonly known as nanogrid.

A nanogrid is a small or miniaturised power system. It is a self sufficient system comprising power generation components, controls and energy storage. A nanogrid may comprise renewable generation sources such as solar Photovoltaics, PV, wind and fuel cells and multiple energy storage devices such as ultracapacitor and batteries to supply various AC and DC loads. A typical install capacity of a nanogrid is less than 50 kW and can be found in residential and small commercial units. As Malaysia is located close to the equator having high solar exposure it provides for a high potential in PV generation.

A nanogrid system can be grid -connected or off-grid. It may comprise of renewable energy based generators such as photovoltaic (PV) and wind, an interface to a local utility grid (for grid -connected systems), energy storage units, and customer loads.

Bi-directional power flow and real-time interactive information flow can be achieved by nanogrids which provides for balance between supply and demand. However, the intermittent nature of distributed renewable resources has an adverse impact on the reliable operation of nanogrids. Therefore, energy storage systems should be with distributed renewable energy generations, being able to store energy surplus and be discharged when energy deficit happens or electricity tariff is high.

A possible configuration of nanogrids is in aggregated nanogrids (smartgrid building cells). Agregated nanogrids can form microgrids (smartgrid building blocks) which can increase power quality and reliability, reduce peak load seen by grid and avoid peak energy costs, reduce transmission and distribution (T&D) losses by having on-site generation and energy storage, supply ancillary services to the grid, accelerate the adoption of distributed and renewable energy sources, and reduce fossil fuel use and carbon emissions. Nanogrid can operate in parallel with the grid, as an autonomous power island or in transition between grid-connected mode and islanded mode of operation.

An energy and power management system is a centralised control that is required to balance the real time power of multiple sources, which include renewable energy generators and energy storage units in a nanogrid to ensure system stability. The energy and power management system acts as a centralised system that interacts with system sensors and local power electronics converters by receiving measured system parameters, processing, making decisions, and sending commands to achieve specific high-level control objectives such as power balance, peak-load shaving and reducing the rate of charge and discharge of battery energy storage during steady-state and transient conditions. Battery lifetime is also an important concern as the cost of battery energy storage is quite a significant portion of the nanogrid systems.

Numerous energy and power management systems have been invented for ensuring an efficient energy conversion system.

One example of an energy and power management system is disclosed in Korean Patent No. KR 101965328 B1 , hereinafter KR 328 B1 entitled ‘Thermoelectric composite grid system with DC nanogrid and its operation method’ having a filing date of 14 November 2017 Applicant: Dongshin Univ Industry Academy Cooperation. KR 328 B1 discloses distributed power source using a DC nanogrid. The invention provides integration of dissimilar energy such as thermal energy and electric energy, a real-time control for operating facilities that include an energy storage system by employing a nanogrid to provide for an efficient energy and power management system that can flexibly and efficiently connect different energy sources with new types and sizes of energy demand. KR 328 B1 comprises a distributed power source, an energy storage system, an energy and power management system. The energy and power management system of KR 328 B1 controls the distributed power source and the energy storage system and grid power source accounting for energy use pattern information of thermal and electrical use load, information of the distributed power source and price information and power generation cost information.

Another example of an energy and power management system is disclosed in United States of America Patent No. US 20100198421 A1 , hereinafter referred to as US 421 A1 entitled “Methods and Apparatus for Design and Control of Multi-port Power Electronic Interface for Renewable Energy Sources’ having a filing date of 29 January 2010, Applicant: University of Texas System. US 421 A1 discloses an energy and power management system that involves sufficient load regulation and interaction between different sources. The concept of Mutli-port Power Electronics Interface as disclosed in US 421 A1 allows for harvesting, storage and dispatch of electrical power by efficiently managing the bidirectional flow of power between renewable sources, storage, power loads and utility grid. US 421 A1 further discloses a first port connected to an energy storage device, a second port configured for unidirectional flow of energy and connected to an energy source device, a third port configured for bidirectional flow of energy and connected to a utility grid.

A further example of an energy and power management system is disclosed in Korean Patent No. KR 101863141 B1 , hereinafter referred to as KR 141 B1 , entitled “Power- controlled energy and power management system using lithium battery and supercapacitor” having a filing date of 11 December 2017, Applicant: KEYSTONE ENERGY CO LTD. KR 141 B1 disclose a power control type energy and power management system that utilizes lithium ion batteries, supercapacitors and renewable energy. The energy and power management system of KR 141 B1 further comprises a bidirectional power conditioning system (Bi-dPCS); a battery management device, a system-side power conversion device and an energy storage system. The invention provides a fusion type 10 kW energy and power management system which copes with a normal load with a lithium-ion battery and a super capacitor having a rapid load that requires instant operation which in turn stabilizes the storage device of the invention providing a more efficient energy and power management system. KR 141 B1 provides the advantage of using both lithium ion battery and supercapacitor whereby sudden change in output of renewable energy, whereby fluctuation in output energy that depends on external factors such as sunlight and wind power can be prevented during charging or discharging of the energy storage device.

There are drawbacks that occur in current energy and power management systems which uses renewable energy to generate electricity. One of the main drawbacks is that the energy storage device such as the batteries and supercapacitors require a highly efficient conversion system having fast dynamics to manage the charge and discharge cycles of the devices. Further, there is need to develop and research on energy and power management system with nanogrid applications where the produced renewable energy source is able to meet the load demands. As the output of renewable energy source in nanogrid is constrained by panel temperature, shading and sun insolation level, hybrid energy storage devices such as batteries and supercapacitors are required to balance the supply and demand of power efficiently while also taking into account of prolonging battery lifetime. Therefore, there is need for providing communication and a balance power transfer between the renewable source, energy storage device and loads in a nanogrid energy and power management system.

The present invention provides an energy and power management system for managing the charge and discharge states of a supercapacitor and battery energy storage system within a nanogrid.

SUMMARY OF INVENTION

The present invention relates to an energy and power management system to ensure demand and supply of renewable energy to an energy load and a method thereof. In particular, the present invention provides an energy and power management system comprising a nanogrid and an energy storage system made up of battery and a supercapacitor.

One aspect of the present invention provides an energy and power management system (100) for managing, harvesting, storing and discharging of electrical power to produce renewable energy. The system (100) comprising a grid (102) linked to a plurality of meters (108a, 108b, 108c, 108d) to control signals and display status and measurement; a plurality of nanogrid panels (104) comprising an Maximum Power Point Tracking, MPPT module system that is connected to a plurality of solar inverters and digital signal processing DSP control for production of renewable energy power that work in communication with the grid (102) being further linked to the plurality of meters (108a, 108b, 108c, 108d); a plurality of energy storage devices (106, 110) that works in communication with the plurality of nanogrid panels (104) that are connected to a DC-AC inverter and further connected to any one of the plurality of meters (108d) for supporting photovoltaic output generation by balancing demand and supply of energy load by means of charging and discharging of the energy storage devices ; and a main meter (112) for measurement and display of input and ouputrenewable energy power to the energy load. The plurality of energy storage devices (106, 110) comprises a plurality of batteries (106) each having a direct current-direct current, DC-DC converter and a DSP control for charging and discharging of the energy storage devices for in terms of balancing demand and supply of the energy load; and at least one graphene supercapacitor (110) comprising a bidirectional converter and a DSP control for injecting an optimum power output to prevent rapid discharge of the plurality of batteries (106) and for extending shelf life of the batteries.

Another aspect of the present invention provides thatthe plurality of nanogrid panels (104) comprising of an 18 kWp Nano PV Panel and a 2-kWp Nano-Light Energy Panel.

Yet another aspect of the present invention provides that the at least one graphene supercapacitor (110) is a 177-F 51 V Nano-graphene supercapacitor. Still another aspect of the present invention provides that the plurality of batteries (106) are at least four batteries of 4.8kWh.

A further aspect of the invention provides that the plurality of batteries (106) are Li-ion batteries.

Yet another aspect of the invention provides that the plurality of batteries (106) for charging and discharging of the renewable energy power in terms of balancing demand and supply of the energy load comprises an idle time feature for ensuring termination of operation of the plurality of batteries at an ambient temperature 0 - 60°C during chargingand -20 - 60°C during discharging.

Another aspect of the invention provides a method (200) for managing, harvesting, storing and discharging of electrical power to produce renewable energy controlling charging and discharging of an energy storage system within an energy and power management system. The method (200) comprising steps of determining a first mode of the energy storage in an energy and power management system where generation of a photovoltaic power is more than a load power (2010); determining a second mode of the energy storage in the energy and power management system where demand of the load power is more than the generation of photovoltaic power (2020); and determining a third mode of the energy storage in the energy and power management system where the photovoltaic power is not available (2030).

A further aspect of the invention provides that the step for determining the first mode where generation of a photovoltaic power is more than a load power (2010) further comprises steps of starting the grid connected mode (202); determining time is less than a maximum 86400s, where if time is more than the maximum 86400s, the time counter will reset , if time is less than a maximum 86400s, the first mode will proceed (204); activating daylight mode from 7am to 7pm (206); determining generated photovoltaic power is more than the load power (208); determining if a terminal voltage of a supercapacitor is between a range of 34V and 48V (210), where if the terminal voltage of supercapacitor is between the range, the photovoltaic power in excess charges the supercapacitor (212), where if the terminal voltage of a supercapacitor is not within the range, an overall power will be determined (214); determining the overall power of more than 0 (214), where if the overall power is less than 0 an inverter rated apparent power is determined (216), where if the inverter rated apparent power is more than an energy storage system power, Qload is injected (218), if the inverter rated apparent power is less than the energy storage system power, the first mode will proceed back to determining time is less than a maximum 86400s (204) if the overall power is more than 0, the first mode will proceed; determining a state of charge of a plurality of batteries for charging and discharging (220), where if the state of charge of the plurality of batteries are between 50% and 90% and the batteries in charging mode, the batteries will be charged (222); if the state of the battery is in discharging mode, the batteries will be in idle state (223); if the state of charge of the plurality of batteries are between 50% and 90% and the batteries in discharging mode, the batteries will be in idle state (222); if the state of charge of the plurality of batteries are not between 50% and 90%, the batteries will proceed withdischarging mode and will be in idle state (224); and determining the overall power of more than 0 (226), if the overall power is more than 0, photovoltaic power is injected to the grid (228); if the overall power is less than 0 determining the energy storage system power is equal to the inverter rated apparent power (230), where if the energy storage system power is not equal to the inverter rated apparent power, Qload will be injected form the inverter (232), where if the energy storage system power is equal to the inverter rated apparent power, the first mode will proceed back to determining time is less than a maximum 86400s (204).

Yet another aspect of the invention provides that the step for determining a second mode of the energy storage system where demandof the load power is more than the photovoltaic power (2020) further comprising steps of starting the grid connected mode (202); determining time is less than the maximum 86400s, where if time is more than the maximum 86400s, the time counter will reset, if time is less than a maximum 86400s, the second mode will proceed (204); activating daylight mode from 7am to 7pm (206); determining generated photovoltaic power is less than the load power (208); determining difference in photovoltaic power and load power which is passed through a low pass filter (236); determining an average power and a high frequency power (238); where determining the high frequency power involves determining that the terminal voltage of a supercapacitor is between the range of 34V and 48V (240), where if the terminal voltage of the supercapacitor does not fall in the range, a high frequency load power is supplied by the grid (242); where if the terminal voltage of the supercapacitor falls within the range the high frequency power is further determined to be below 5 kW (244), where if it is below 5 kW the supercapacitor supplies actual transient power required (248), where if the high frequency power is above 5 kW the supercapacitor supplies 5kW (246); determining the average power of less than 20kW (250), determining a state of charge of the plurality of batteries for charging and discharging (252), where if the state of charge of the plurality of batteries are between 50% and 90% and the batteries in discharging mode, the batteries will be discharged (254); if the state of charge of the battery in in charging mode, the battries will be in idle state (255); if the state of charge of the plurality of batteries are not between 50% and 90%, the batteries will proceed with charging mode and will be idle state (256); determining the energy storage system power is equal to load power (258), where if the energy storage system power is equal to load power the second mode will proceed back to determining time is less than a maximum 86400s (204), where if the energy storage system power is not equal to the load power , the load power is supplied from the grid (262); and determining the energy storage system power is equal to inverter rated apparent power (260), where if the energy storage system power is equal to the inverter rated apparent power, the second mode will proceed back to determining time is less than a maximum 86400s, where if the energy storage system power is not equal to the inverter rated apparent power the inverter inject Qload within its rated apparent power (264).

Still another aspect of the invention provides that the step for determining a third mode of the energy storage system where the photovoltaic power is not available (2030) further comprising steps of starting the grid connected mode (202); determining time is less than the maximum 86400s, where if time is more than the maximum 86400s, the time counter will reset, if time is less than a maximum 86400s, the third mode will proceed (204); activating non-peak mode from 7pm to 7am (206); determining if the terminal voltage of a supercapacitor is between a range of 34V and 48V (266), where if the terminal voltage of the supercapacitor falls within the range, supercapacitor is charged by grid at 5 kW (368), where if the terminal voltage of the supercapacitor does not fall within the range, the third mode will proceed; determining the state of charge of the plurality of batteries for charging and discharging (270), where if the state of charge of the plurality of batteries are between 50% and 90% the the plurality of batteries are charged from grid at 0.3C and loads are supplied by the grid (272); where if the state of charge of the plurality of batteries are not between 50% and 90%, an AC/DC inverter compensates reactive power to maintain the PF at 1 and supercapacitor bank compensates real power loss of the energy and power management system (274); and proceeding back to determining time is less than a maximum 86400s (204).

The present invention consists of features and a combination of parts hereinafter fully described and illustrated in the accompanying drawings, it being understood that various changes in the details may be made without departing from the scope of the invention or sacrificing any of the advantages of the present invention.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

To further clarify various aspects of some embodiments of the present invention, a more particular description of the invention will be rendered by references to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the accompanying drawings in which:

Figure 1.0a illustrates a general overview of the nanogrid energy and power management system of the present invention.

Figure 1 .Ob illustrates a Simulink model of the nanogrid energy and power management system of the present invention

Figure 1.1a illustrates a graph showing the characteristics of the current voltage and photovoltaic voltage of the nano photovoltaic panel of the energy and power management system.

Figure 1.1b illustrates a graph showing the characteristics of the current voltage and photovoltaic voltage of the nano light energy panel of the energy and power management system.

Figure 1.1c illustrates a specification of the nano photovoltaic panel and the nano light energy panel of the energy and power management system.

Figure 1.2a illustrates a boost converter with Perturb and Observe algorithm of a Maximum Power Point Tracking system.

Figure 1 .3a illustrates a voltage source converter outer and inner control loop.

Figure 1 .3b illustrates a table showing the proportional and integral constants employed for the photovoltaic Inverter PI controller. Figure 1 .3c illustrates the Simulik model of the three-phase inverter for photovoltaic grid connected system.

Figure 1 .3d illustrates a table showing a photovoltaic inverter specification.

Figure 1 .4a illustrates a table showing battery specification of the present invention.

Figure 1.4b illustrates a table showing ultra-capacitor specification of the present invention.

Figure 1.5a illustrates a bidirectional buck-boost DC-DC converter connected to the batteries and the ultracapacitor in the nanogrid of the present invention.

Figure 1 .5b illustrates a control scheme of bidirectional converter of the present invention.

Figure 1 .6a illustrates an inverter based PQ control for the Energy Storage System, ESS.

Figure 1 .6b illustrates a table showing the parameter of the ESS Inverter PI controller.

Figure 1 .6c illustrates a table showing an ESS Inverter specification.

Figure 2.0a illustrates a flowchart on the control philosophy of the energy and power management system.

Figure 2.0b illustrates a flowchart of Mode 1 of the control philosophy of the energy and power management system.

Figure 2.0c illustrates a flowchart of Mode 2 of the control philosophy of the energy and power management system.

Figure 2.0d illustrates a system for transient and average power extraction.

Figure 2.0e illustrates a flowchart of Mode 3 of the control philosophy of the energy and power management system. Figure 3.0a illustrates the simulation results of sun irradiance and temperature against time.

Figure 3.0b illustrates the simulation results of the photovoltaic output power.

Figure 3.0c illustrates the simulation result of the DC and AC voltage and current waveforms of the photovoltaic inverter

Figure 3.0d illustrates the simulation result of load active and load reactive power.

Figure 3.0e illustrates the active and reactive power of the ESS inverter.

Figure 3. Of illustrates the active and reactive power of the ac main grid.

Figure 3.0g illustrates an AC voltage and current of the ESS inverter.

Figure 3. Oh illustrates a graph showing the state of charge of all four battery modules.

Figure 3.0i illustrates a graph showing the state of charge of the supercapacitor.

Figure 4.0 illustrates a schematic diagram showing the control system hardware connection and power management system of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

The present invention relates to an energy and power management system to ensure supply of renewable energy to an energy load. In particular, the present invention provides an energy and power management system comprising a nanogrid and an energy storage module made up of battery and a supercapacitor. Hereinafter, this specification will describe the present invention according to the preferred embodiments. It is to be understood that limiting the description to the preferred embodiments of the invention is merely to facilitate discussion of the present invention and it is envisioned without departing from the scope of the appended claims.

The present invention provides an energy and power management system for managing the charge and discharge states of the supercapacitor and battery energy storage module that involves nanogrid application.

With the present invention, the problem of output of a renewable-energy source nanogrid being constrained by ambient and panel temperature, shading and sun insolation levels are overcome. The supercapacitor of the present invention is able to meet the high load power profile that cannot be met by photovoltaic generation alone. The batteries further ensures continuous supply of energy from the nanogrid to the load. An efficient and homogenous charging and discharging system of the present invention allows for an extended battery lifecycle. The entire energy and power management system allows for optimum communication and balance power transfer between the renewable energy produced by the nanogrid panels, energy storage device such as the supercapacitor and batteries and the load demand.

Reference is first made to Figure 1.0a. Figure 1.0a illustrates an energy power management system (100) for managing, harvesting, storing and discharging of electrical power to produce renewable energy. The energy and power management system comprises a grid (102) linked to a plurality of meters (108a, 108b, 108c, 108d) to control signals and display status and measurement, a plurality of nanogrid panels (104) comprising a maximum power point tracking, MPPT module that is connected to a plurality of solar inverters and DSP control for production of renewable energy power that work in communication with the grid (102) further linked to the plurality of meters. The plurality of nanogrid panels (104) are an 18 kWp Nano PV Panel and 2-kWp Nano- Light Energy Panel. Photovoltaic generation within the energy and power management system with nanogrid application obviates the need for long distance transmission cables and minimises the distribution lines length. Generally, photovoltaic, PV generators are connected close to the load point.

The system further comprises a plurality of energy storage devices (106, 110) that works in communication with the plurality of nanogrid panels (104) that are connected to a DC- AC inverter and further connected to one of the plurality of meters (108d) for supporting photovoltaic output generation by balancing demand of energy load and supply of renewable energy by means of charging and discharging of the energy storage devices . The present invention also includes a main meter (112) for measuring and displaying input and ouput of renewable energy power to the energy load.

The plurality of energy storage devices (106, 110) comprises a plurality of batteries (106) and at least one graphene supercapacitor (110).

The plurality of batteries each have a DC-DC converter and a DSP control for charging and discharging of the renewable energy power in terms of balancing demand and supply of the energy load. The batteries (106) are at least four batteries of 4.8kWh and are Li-ion batteries. Further, charging and discharging of renewable energy in the batteries flows in bi-direction. The plurality of batteries (106) comprises an idle time feature that ensures termination of operation of the plurality of batteries at a temperature 0 - 60°C during charging and -20 - 60°C during discharging. Further, the plurality of batteries (106) for charging and discharging of energy storage devicesin terms of balancing demand and supply of the energy load comprises charging of the storage energy devices during off peak hours from 7pm to 7am and charging and discharging of the renewable energy power in terms of balancing demand and supply of the energy load comprises supplying the renewable energy power during peak hours of 7am to 7pm. The Li-ion batteries ensure that photovoltaic, PV power generation is able to be dispatched in terms of demand and supply.

The at least one graphene supercapacitor (110) comprises a bidirectional converter and a DSP control for injecting an optimum power output to prevent rapid discharge of the plurality of batteries and for extending shelf life of the batteries. The at least one graphene supercapacitor (110) is a 177-F 51 V Nano-graphene supercapacitor. The at least one graphene supercapacitor (110) for injecting an optimum power output to prevent rapid discharge of the plurality of batteries and extend shelf life of the batteries is at most 5kW. A graphene supercapacitor furnishes the transient currents for the loads in close proximity. The existence of large transient currents in the system is that the line impedance at low-voltage network have low X/R ratio where there is high resistance and low inductive reactance. Without the supercapacitor, the transient current will be partly furnished by the main grid and partly by a chemical battery system. This leads to the main grid not being efficient and having premature failures in the chemical battery system. The battery and the supercapacitor of the present invention share a common DC bus voltage that interfaces with the AC grid through a grid-connected voltage source inverter. The controllers in Figure 1.0a regulate the DC bus voltage while managing the charging and discharging of the battery storage and the supercapacitor.

Reference is made to Figure 1.0b illustrating a Simulink model of the nanogrid. The Simulink model of the nanogrid is used to test the energy and power management system. The main components in the nanogrid energy and power management system is the photovoltaic system, the maximum power point tracking, MPPT, the photovoltaic, PV Inverter, energy storage units, the bidirectional DC-DC Converter and ESS Inverter.

The energy and power management system of the present invention uses two types of nanogrid photovoltaic panels which form the photovoltaic system which are the 56, 335- Wp Nano photovoltaic, NPV panel for 18.76 kWp output and 22, 96-Wp Nano Light Energy Panel, NLEP for 2.11 kWp output. Figure 1.1a shows the characteristics of the current-voltage and power-voltage of the nano photovoltaic panel, NPV of the energy and power management system modelled using the PV ARRAY block in MATLAB or SIMULINK. Figure 1.1b shows the characteristics of the current-voltage and powervoltage of the nano light energy panel, NLEP, of the energy and power management system modelled using the PV ARRAY block in MATLAB or SIMULINK. Figure 1.1c illustrates a specification of the nano photovoltaic panel, NPV and the nano light energy panel, NLEP of the energy and power management system. The specifications of both types of photovoltaic panels are used to define the parameters in the PV ARRAY block. The total output power from the photovoltaic system is designed to be 20 kW. The maximum power of the Nano-photovoltaic, NPV is 300 W whereas the maximum power of the Nano-light energy panel, NLEP is 96 W. Further, the open circuit voltage of the Nano-photovoltaic, NPV is 45.3 V whereas the open circuit voltage of the Nano-light energy panel, NLEP is 100 V. The short circuit current of the Nano- photovoltaic, NPV is 8.86 A whereas the short circuit current of the Nano-light energy panel, NLEP is 1.57 A. The maximum voltage of the Nano-photovoltaic, NPV is 36.7 V whereas the maximum voltage of the Nano-light energy panel, NLEP is 76 V. The maximum current of the Nano-photovoltaic, NPV is 8.18 A whereas the maximum current of the Nano-light energy panel, NLEP is 1 .26 A.

Figure 1.2a illustrates a boost converter with Perturb and Observe, P&O algorithm of a Maximum Power Point Tracking, MPPT module . A maximum power point tracking, MPPT module comprises the boost converter and the P&O algorithm to track the maxiimum power point of a photovoltaic system under various environment conditions. The P&O algorithm compares a previously delivered power with the one after disturbance by periodically varying the voltage of the panel with incremental steps to reduce the oscillation around the MPPT. The P&O algorithm has a wide application in commercial systems due to its simplicity and involvement of few measured parameters.

The environment condition comprising sun irradiance, Ir and ambient temperature, T are assigned as input to PV ARRAY block as also shown in Figure 1 .0b. The output power of PV system will be changed based on the values of Ir and T. Figure 1 .2a shows that the MPPT with P&O algorithm is used to determine a duty cycle of the boost converter. The calculation of duty cycle is carried out by the MPPT algorithm to track the maximum power of photovoltaic, PV array. The boost converter and MPPT algorithm are simulated by MATLAB or SIMULINK and the switching frequency is 20 kHz. To convert the output DC Photovoltaic, PV output voltage to AC, a three-phase voltagesource grid-connected inverter is used which is then delivered to the connected load, storage devices, or utility grid.

The measured AC voltage u_a, u_b, and u_c and current i_a, lb, and i_c are measured and undergoes dqO transformation using Park transformation to convert the time-varying values to time invariant values as:

Figure 1.3a illustrates a voltage source converter outer and inner control loop. A cascaded control loop that employs outer loop dc-voltage control and inner loop dq- current control is used in the Photovoltaic, PV inverter control. At the outer de control loop, the active current is controlled indirectly through the DC-link voltage regulation. In a Photovoltaic, PV inverter, the reactive current reference is zero. The DC-link voltage control is taken as the outer control loop to keep the output voltage of PV inverter constant even when the sun irradiance and ambient temperature changes.

The d- and q- axis output currents are coupled to each other. Further, the load voltage influences the control dynamics. Therefore, the output voltage reference which are u*_Cd and u*_Cq are modified by adding one decoupling term and on feed-forward voltage as follows:

14*cd ⁼ Tied + jLiq - Ud

U*cq ⁼ Wcq " W Lid ~ Uq

Further, the inner control loop controls the current injected to the AC load. The output voltage reference of the DC/AC converter is obtained from the dq-reference current with an inverse Park transformation. The voltage reference is then used for the pulse-width modulation, PWM to synthesize corresponding output voltage by switching the DC/AC converter. A phase-locked loop, PLL is used as the synchronization unit that is required for the reference frame transformation to keep synchronizing with the grid. Figure 1 .3b illustrates a table showing the proportional and integral gains of the photovoltaic Inverter proportional integral, PI controller that are employed in Simulink. The constants for proportional gain, K_p and. integral gain, Ki are shown in the table. The propotional gain K_p of the DC-link voltage and current controllers are 1 and 0.2, respectively.. The integral gains for the DC-link voltage and current controllers are K is 0 and 20, respectively.

Figure 1.3c illustrates a Simulink model of the three-phase inverter for photovoltaic grid connected system. The Voltage Source Converter, VSC is built in MATLAB or SIMULINK software. The output voltage reference of the Voltage DC, VDC controller is used as the input to pulse-width modulation, PWM block operating under 20 kHz which generates signals of the Photovoltaic, PV inverter. The specification of a photovoltaic inverter employed by the present invention is shown in Figure 1.3d. The specification includes a grid voltage of 400 V, a grid frequency of 50 Hz, a switching frequency of 20 kHz, a power rating of 20 kW, a DC-link voltage of 450 V, a base power of 100 KVA, a base voltage of 400 V, R filter of 0.139 Q, L Filter of 15.4 mH and a C Filter of 0.249 mF. The specification of the photovoltaic system model is constructed in Simulink to verify the effectiveness of the energy and power management system. The AC side RLC filters are defined as follows:

F²

L - -

2n f. P

Where the value of X/R ratio is 7 and f_c = 0.1 * /(switching frequency).

The energy storage system in the nanogrid of the present invention consists of four Li- ion batteries and one supercapacitor. These units are connected into grid through five bidirectional DC-DC converter and a three-phase inverter. The battery specification and the ultra-capacitor specification employed by the present invention is shown in Figure 1 .4a and Figure 1 .4b respectively. Figure 1.5a illustrates a bidirectional buck-boost DC-DC converter connected to the batteries and the ultracapacitor in the nanogrid of the present invention .The bidirectional buck-boost converter allow power in the energy storage units to flow in two directions for charging or discharging.

Figure 1 .5b illustrates a control scheme of bidirectional converter of the present invention. As illustrated in Figure 1.5b, DC-DC converter that is controlled using PI controller is used to boost the low voltage side to 800V. Another PI controller is used to control the charging and discharging states of the energy storage units. The current reference values of the battery connected dc-dc converter are set based on the direction of the power flow, where the charging state is activated by a current reference value of -100 A and the discharging state is activated by a current reference value of 100 A. It is also shown that the output signal from control loop P is used to generate the 20 kHz PWM switching signal of converter.

Figure 1.6a illustrates an inverter based PQ control, particularly illustrating the local control loop of the ESS inverter.A three-phase inverter delivers the charge and discharge power from the energy storage based on the commands provided by the central power management system. The inverter controller has a PQ control in the outer control loop. The concept of the PQ control is based on the instantaneous power theory. In the synchronous dq-reference frame, the instantaneous active power P and reactive power Q can be calculated as:

where Ud, u_qand id, i_q are the measured ac voltage and currents.

The reference real and reactive power, P_ref* and Qref^! are negative when power is obtained from the point of AC connection. On the other hand Pref* and Qref* are positive when the power is injected to the point of common AC connection.. Figure 1 .6b is a table showing the tuned constants for the two local PI controllers while Figure 1 .6c shows the electrical specifications of the ESS inverter.

Figure 2.0a illustrates a flowchart on the methodology of the present invention particularly the control philosophy of the energy and power management system .The centralised control of the ESS in the nanogrid is divided into three modes of operation, the first and second modes are working during the peak hours between 7 am and 7 pm, while the third mode is activated for the other 12 hours between 7 p.m. and 7 a.m. As illustrated in Figure 2.0a, the method (200) for for managing, harvesting, storing and discharging of electrical power produced by renewable energy via controlling charging and discharging of an energy storage system within an energy and power management system comprising steps of first determining a first mode of the energy storage in an energy and power management system where generation of a photovoltaic power is more than a demand load power (2010). Thereafter, a second mode of the energy storage in the energy and power management system is determined where a demand of the load power is more than a generation of photovoltaic power (2020). Subsequently, a third mode of the energy storage in the energy and power management system is determined where the photovoltaic power is not available (2030).;

In Mode 1 the required load power, Pload is supplied by the photovoltaic generated power Ppv. The PV generated power is in access when:

This is known as State 1 . In State 1 , the excess power from PV generation charges the supercapacitor if the measured terminal voltage of supercapacitor satisfies the condition of:

where V_scmin is 34V and V_scmax is 48V. The current reference for the dc-dc converter connected to the supercapacitor can be determined as:

As the rated power of the dc-dc converter is 5kW, the maximum charging power of the supercapacitor is limited to 5kW.

Another state refers to state 2 which applies for charging the Li-ion battery modules. In State 2, the Li-ion battery modules (in charging state) are charged when,

PPV - Psc > 0 where Puc is the power charging the supercapacitor and when the battery module state- of-charge, SOC is within the SOC limits of,

n is 1 , 2, 3, or 4 denoting each of the four Li-ion battery modules in the nanogrid.

In order to increase the battery lifetime and reduce cycling frequency of charging and discharging, a homogenous charging-discharging technique has been carried out. Using this technique, a Li-ion battery module that is set in the charging state will be charged using the excess PV generation until the battery reaches the predetermined maximum SOC of 90% and the state of the battery is set to discharging. If a battery module has pre-state of discharging, the corresponding dc-dc converter reference current is set to 0 and the battery module remains idle to fulfil the homogenous charging control.

A father state is state 3 which applies for export of PV generated power to the main grid.

State 3 is achieved when

where the energy storaoe svstem newer P_Ess is the sum of Puc and the power from Li- ion battery

The PV generated power that is exported to the grid is

In order to maintain the PF at 1 , the load reactive power will be injected via the ESS inverter based on a power comparison between the energy storage system active power and inverter rated apparent power.

(Qload)² < (Sinv)² - (PESS)

The methodology of Mode 1 of the control philosophy of the energy and power management system as depicted in Figure 2.0b illustrates in detail the steps involved for determining a first mode of an the energy storage in an energy system where generation of a photovoltaic power is more than a load power (2010). Firstly, a grid connected mode is started (202). Thereafter, it is determined if time is less than a maximum 86400s, where if time is more than the maximum 86400s, the time counter will reset, if time is less than a maximum 86400s, the first mode will proceed (204). Subsequently, daylight activating mode is activated from 7am to 7pm (206). It is determined if generated photovoltaic power is more than the load power (208) and it is further determined if a terminal voltage of a supercapacitor is between a range of 34V and 48V (210), where if the terminal voltage of supercapacitor is between the range, the photovoltaic power in excess charges the supercapacitor (212), where if the terminal voltage of a supercapacitor is not within the range, an overall power will be determined (214).

In determining the overall power of more than 0 (214), where if the overall power is less than 0, then overall power (energy storage system power) is determined to be less than an inverter rated apparent power (216), where if the inverter rated apparent power is more than an energy storage system power, Qload is injected (218), if the inverter rated apparent power is less than the energy storage system power, the first mode will proceed back to determining time is less than a maximum 86400s (204) if the overall power is more than 0, the first mode will proceed. Susbequently, a state of charge of a plurality of batteries for charging and discharging is determined (220), where if the state of charge of the plurality of batteries are between 50% and 90% and the batteries in charging mode, the batteries will be charged (222); if the state of the battery is in discharging mode, the batteries will be in idle state (223); if the state of charge of the plurality of batteries are between 50% and 90% and the batteries in discharging mode, the batteries will be in idle state (222); if the state of charge of the plurality of batteries are not between 50% and 90%, the batteries will proceed with discharging mode and will be in idle state (224); and determining the overall power of more than 0 (226), if the overall power is more than 0, photovoltaic power is injected to the grid (228); if the overall power is less than 0 determining the energy storage system power is equal to the inverter rated apparent power (230), where if the energy storage system power is not equal to the inverter rated apparent power, Qload will be injected form the inverter (232), where if the energy storage system power is equal to the inverter rated apparent power, the first mode will proceed back to determining time is less than a maximum 86400s (204).

In describing Mode 2, the power generation of PV cannot meet the load demand when

Therefore, the excess load demand is supplied by energy storage units, ESU. The supercapacitor supplies the transient power while the battery modules supply the average power. When the voltage limits of the supercapacitor is,

The supercapacitor discharges the amount of transient power, limited to 5kW. Otherwise when the SOC of the battery modules is within the limits of,

the state of the battery i.e. charge or discharge state is determined. With homogenous charging-discharging technique, a Li-ion battery module that is set in the discharging state discharges as,

where N is the total number of Li-ion battery modules in the discharging state. A battery module in the discharging state, the battery will not be charged until it reaches the predetermined minimum SOC of 50%. If a battery module has a state of charging, the battery remains idle.

The methodology of Mode 2 of the control philosophy of the energy and power management system as depicted in Figure 2.0c illustrates in detail the steps involved for determining a second mode of the energy storage system where demand of the load power is more than the generation of photovoltaic power (2020). Firstly, the grid connected mode (202). Thereafter, it is determined if time is less than the maximum 86400s, where if time is more than the maximum 86400s the time counter will reset, if time is less than a maximum 86400s, the second mode will proceed (204). Subsequently, daylight mode is activated from 7am to 7pm (206). It is determined if generated photovoltaic power is less than the load power (208) and the difference in photovoltaic power and load power which is passed through a low pass filter is determined (236). Subsequently, an average power and a high frequency power (238) is determined; where determining the high frequency power involves determining that the terminal voltage of a supercapacitor is between the range of 34 and 48V (240), where if the terminal voltage of the supercapacitor does not fall in the range, a high frequency load power is supplied by the grid (242); where if the terminal voltage of the supercapacitor falls within the range the high frequency power is further determined to be below or equal to 5 kW (244), where if it is below or equal to 5 kW the supercapacitor supplies actual transient power required (248), where if the high frequency power is above 5 kW the supercapacitor supplies 5kW (246).

The average power of less than 20kW is thereafter determined (250). The state of charge of the plurality of batteries for charging and discharging is determined (252), where if the state of charge of the plurality of batteries are between 50% and 90% and the batteries in discharging mode, the batteries will be discharged (254); if the state of the battery is in charging mode, the batteries will be in idle state (255); if the state of charge of the plurality of batteries are not between 50% and 90%, the batteries will proceed with charging mode and will be idle state (256);

The energy storage system power is determined as equal to load power (258), where if the energy storage system power is equal to load power the second mode will proceed back to determining time is less than a maximum 86400s (204), where if the energy storage system power is not equal to the load power , the load power is supplied from the grid (262). At the same time, the energy storage system power is determined as equal to inverter rated apparent power (260), where if the energy storage system power is equal to the inverter rated apparent power, the second mode will proceed back to determining time is less than a maximum 86400s, where if the energy storage system power is not equal to the inverter rated apparent power the inverter injects Qload with its rated apparent power (264).

Figure 2.0d illustrates a system for transient and average power extraction . The difference between the load and PV generated power, P_Ess is passed through a low pass filter, LPF. The output of the LPF is the average power Pave that is also the reference discharging power from the battery modules, which is limited to Pb,n = 5 kW. If all four battery modules are in the discharging state, the maximum average power is limited by the rated power of the battery. The reference discharge power from supercapacitor is Psc. When the energy storage system does not supply all load demand, the required load demand is imported from the grid.

PG rid = fload - PPV - PESS

In order to maintain the PF at 1 , the load reactive power will be injected via the ESS inverter based on a power computed from the energy storage system active power and inverter rated apparent power.

Figure 2.0e illustrates a flowchart of Mode 3 of the control philosophy of the energy and power management system. In particular, the control philosophy for charging of the ESUs between 7 p.m. and 7 a.m when PV generators are not operating is described. After 7p.m. it can be assumed that there is no power generation by photovoltaic panels. Therefore, based the control philosophy, all load demand is supplied by grid. Moreover, the electricity tariff is lower in this duration. Therefore, when the battery module and supercapacitors are within the limits of,

y * scrrn -n — < sc < 'soaax

They are charged until they reached the maximum SOC. The power imported from the grid is

In order to maintain the PF at 1 , the load reactive power will be injected via the ESS inverter based on a power comparison between the energy storage system active power and inverter rated apparent power as shown below:

The methodology of Mode 3 of the control philosophy of the energy and power management system as depicted in Figure 2.0e illustrates in detail the steps involved for determining a third mode of the energy storage system where the photovoltaic power is not available (2030). Firstly, the grid connected mode is started (202). It is determinined if time is less than the maximum 86400s, where if time is more than the maximum 86400s, the time counter will reset, if time is less than a maximum 86400s, the third mode will proceed (204); activating non-peak mode from 7pm to 7am (206); determining if the terminal voltage of a supercapacitor is between a range of 34V and 48V (266), where if the terminal voltage of the supercapacitor falls within the range, supercapacitor is charged by grid at 5 kW per terminal voltage of supercapacitor (368), where if the terminal voltage of the supercapacitor does not fall within the range, the third mode will proceed. Subsequently, the state of charge of the plurality of batteries for charging and discharging (270), where if the state of charge of the plurality of batteries are between 50% and 90% the the plurality of batteries are charged from grid at 0.3C and loads are supplied by the grid (272); where if the state of charge of the plurality of batteries are not between 50% and 90%, an AC/DC inverter compensates reactive power to maintain the PF at 1 and supercapacitor bank compensates real power loss of the energy and power management system (274); and proceeding back to determining time is less than a maximum 86400s (204).

The simulation results are presented in four scenarios to verify the performance of power management system under the varying of load profile and environmental conditions.

Figure 3.0a illustrates the simulation results of sun irradiance and temperature against time. Figure 3.0b illustrates the simulation results of the photovoltaic output power while Figure 3.0c illustrates the simulation result of the DC and AC voltage and current waveforms of the photovoltaic inverter and Figure 3.0d illustrates the simulation result of load active and load reactive power. The environmental conditions and load requirements are in step change profile for every one second.

The output power of PV is about 20 kW. Since the load demand is less than the generated power at 8 kW, the PV output power is enough to supply the load and charge the energy storage units. The supercapacitor is charged. Moreover, all four batteries are charged..

Figure 3.0e illustrates the active and reactive power of the ESS inverter while Figure 3. Of illustrates the active and reactive power of the ac main grid. The active and reactive power have to be analysed with the active and reactive power of the PV generator and load. Note that, ESS charging power is negative and discharging power is positive.

Figure 3.0g illustrates an AC voltage and current of the ESS inverter. Figure 3. Oh illustrates a graph showing the state of charge of a battery module. All batteries are in the charging state. Battery modules 1 and 2 have SOC below 90% and modules 3 and 4 have SOC above 50%. Figure 3.0i presents the state-of-charge of the supercapacitor.

For an ESS charging of 0=£t<1s, the output power of PV is about 20 kW. Since the load demand is less than the generated power at 8 kW, the PV output power is enough to supply the load and charge the energy storage units. The supercapacitor is charged. Moreover, all four batteries are charged. When the SOC of battery modules 1 and 2 reach 90%, the discharging state of the modules is triggered and the operation of the dc- dc converter connected to the battery modules remain idle from t = 0.5s. No power is imported or exported to the grid. The load reactive power requirement is met by the reactive power from the ESS inverter.

For ESS Charging of 1 s=t<2 s, the output power of PV is lowered to 2 kW as the solar irradiance is 200 Wh/m² and with a high ambient temperature. The load active power requirement increased to 13 kW. Therefore, the ESUs, discharges. Supercapacitor do not discharge as this is the average power. Battery modules 1 and 2 discharges an aggregated power of 10 kW. Battery modules 3 and 4 remain idle as they are in the charging state. The load reactive power requirement is met by the reactive power from the ESS inverter.

For ESS Charging of 2s=t<3s, the output power of PV is increased to 18 kW as the solar irradiance is increased to 800 Wh/m². The load active power requirement increased to 10 kW. There is more power from the PV generator after meeting the load demand, which is used to charge the ESUs. As battery modules 3 and 4 are in charging state, the batteries will be charged by excess PV output power. Battery modules 1 and 2 are still in the discharging state. Hence, the modules are not charged.

For ESS Charging of 3s=t<4s, the output power of PV is decreased to zero as the solar irradiance is reduced to 0 when the nanogrid is operated between 7 p.m. and 7 a.m.. The load active power requirement is 5 kW. Battery modules 1 - 4 are charged from the grid as the SOCs are between 50% and 90% . The ESS inverter also supplies the load and PV AC filter reactive power requirements. Figure 4.0 is a schematic diagram illustrating the control system hardware connection of a nanogrid energy power management system of the present invention. As illustrated in Figure 4.0, the transfer of data within the nanogrid power management system, NPMS, is enabled by a local area network, LAN, with TCP/IP and CANbus protocols. The main components connection in the NPMS network are the database, weather station, a network hub, a programmable logic controller, PLC and HDMI display. Additionally, each power device is IP enabled and is also able to transmit and receive data. Power components connected in the NPMS network are nano-light energy panel, Monocrystalline Nano-Coated PV panels, solar inverters, batteries, dc-dc converters, ultra-capacitors, bidirectional converters, circuit breakers, relays, and meters. Each power component can sent control signals, and provide status and measurement readings. The PLC is the central interface for incoming and outgoing data. The rulebased finite-state machine is implemented in the PLC. Each component on the network is identified with an IP address. The PLC is assigned a static IP address. Readings from all sensors and devices are collected by the PLC periodically. All data is stored locally in the PLC as well as in a server database located off-site. Readings are also displayed on a monitor for live views of past and current data trends.

In summary, the energy and power managaement system of the present invention functions as a rule-based finite-state machine that determines the charge and discharge states for supercapacitor and battery energy storage in a nanogrid application, and ensures unity power factor at the load side. The energy and power management system of the present invention provides for battery-supercapacitor energy storage system that supports the PV output generation in a modular nanogrid, supports high-frequency power output, provides PV output power levelling and power factor control of the load. Moreover, the battery storage device lifetime is prolonged by ensuring homogenous charging or discharging. When the battery is in the charging state, it continues to be in the charging mode until the predetermined maximum SOC is reached and vice versa. Moreover, idle time is introduced in the homogenous charging or discharging state to ensure that the battery will not operate in over temperature condition. High-frequency power discharging role is given to the supercapacitor. The power quality at the point of connection is considered by injecting reactive power within the rated apparent power of the inverter in the ESS. The communication and a balance power transfer between the RE source, energy storage device and loads are carried out in real time in the present invention. Throughout this specification, unless the context requires otherwise, the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated step or element or integer or group of steps or elements or integers, but not the exclusion of any other step or element or integer or group of steps, elements or integers. Thus, in the context of this specification, the term “comprising” is used in an inclusive sense and thus should be understood as meaning “including principally, but not necessarily solely”.

Claims

1. An energy and power management system (100) for managing, harvesting, storing and discharging of electrical power to produce renewable energy comprising: a grid (102) linked to a plurality of meters (108a, 108b, 108c, 108d) to control signals and display status and measurement, a plurality of nanogrid panels (104) comprising a Maximum Power Point Tracking, MPPT module connected to a plurality of solar inverters and digital signal processing, DSP control for producing renewable energy in communication with the grid (102) being linked to the plurality of meters (108a, 108b, 108c, 108d); a plurality of energy storage devices (106, 110) in communication with the plurality of nanogrid panels (104) are connected to a DC-AC inverter and further connected to any one of the plurality of meters (108d) for supporting photovoltaic output generation by balancing demand and supply of energy load by means of charging and discharging of the energy storage devices ; a main meter (112) for measuring and displaying input and output of renewable energy to the energy load; characterized in that the plurality of energy storage devices (106, 110) comprises: a plurality of batteries (106) each having a direct current- direct current, DC-DC converter and a DSP control for charging and discharging of energy storage devices for balancing demand and supply of the energy load; at least one graphene supercapacitor (110) comprising a bidirectional converter and a DSP control for injecting an optimum power output to prevent rapid discharge of the plurality of batteries (106) and for extending shelf life of the batteries.

2. The energy and power management system of claim 1 , wherein the plurality of nanogrid panels (104) comprising a 18 kWp Nano PV Panel and a 2-kWp NanoLight Energy Panel.

3. The energy and power management system of claim 1 , wherein the at least one graphene supercapacitor (110) is a 177-F 51 V Nano-graphene supercapacitor.

4. The energy and power management system of claim 1 , wherein the plurality of batteries (106) are at least four batteries of 4.8kWh.

5. The energy and power management system of claim 1 , wherein the plurality of batteries (106) are Li-ion batteries.

6. The energy and power management system of claim 1 wherein the plurality of batteries (106) for charging and discharging of renewable energy power in terms of balancing demand and supply of the energy load comprises an idle time feature for ensuring termination of operation of the plurality of batteries at a temperature range of 0 - 60°C during charging and -20 -60°C during discharging.

7. A method (200) for managing, harvesting, storing and discharging of electrical power to produce renewable energy and power management system comprising steps of: determining a first mode of an energy storage in an energy and power management system where generation of a photovoltaic power is more than a load power (2010); determining a second mode of the energy storage in the energy and power management system where demand of the load power is more than the generation of photovoltaic power (2020); and determining a third mode of the energy storage in the energy and power management system where the photovoltaic power is not available (2030).

8. The method (200) of claim 7, wherein determining a first mode of an energy storage in an energy system where generation of a photovoltaic power is more than a load power (2010) further comprises steps of: starting a grid connected mode (202); determining time is less than a maximum 86400s, where if time is more than the maximum 86400s, the time counter will reset, if time is less than a maximum 86400s, the first mode will proceed (204); activating daylight mode from 7am to 7pm (206); determining generated photovoltaic power is more than the load power (208); determining if a terminal voltage of a supercapacitor is between a range of 34V and 48V (210), where if the terminal voltage of supercapacitor is between the range, the photovoltaic power in excess charges the supercapacitor (212), where if the terminal voltage of a supercapacitor is not within the range, an overall power will be determined (214); determining the overall power of more than 0 (214), where if the overall power is less than 0 an inverter rated apparent power is determined (216), where if the inverter rated apparent power is more than an energy storage system power, Qload is injected (218), if the inverter rated apparent power is less than the energy storage system power, the first mode will proceed back to determining time is less than a maximum 86400s (204) if the overall power is more than 0, the first mode will proceed; determining a state of charge of a plurality of batteries for charging and discharging (220), where if the state of charge of the plurality of batteries are between 50% and 90% the batteries will be charged (222); if the state of the battery is in discharging mode, the batteries will be in idle state (223); if the state of charge of the plurality of batteries are not between 50% and 90%, the batteries will proceed with discharging and will further reach an idle state (224); and determining the overall power of more than 0 (226), if the overall power is more than 0, photovoltaic power is injected to the grid (228); if the overall power is not less than 0 determining the energy storage system power is equal to the inverter rated apparent power (230), where if the energy storage system power is equal to the inverter rated apparent power, Qload will be injected form the inverter (232), where if the energy storage system power is not equal to the inverter rated apparent power, the first mode will proceed back to determining time is less than a maximum 86400s (204).

The method (200) of claim 7, wherein determining a second mode of the energy storage system where generation of the load power is more than the photovoltaic power (2020) further comprising steps of starting the grid connected mode (202); determining time is less than the maximum 86400s, where if time is more than the maximum 86400s, the time counter will reset,, if time is less than a maximum 86400s the second mode will proceed (204); activating daylight mode from 7am to 7pm (206); determining generated photovoltaic power is less than the load power (208); determining difference in photovoltaic power and load power which is passed through a low pass filter (236); determining an average power and a high frequency power (238); where determining the high frequency power involves determining that the terminal voltage of a supercapacitor is between the range of 34V and 48V (240), where if the terminal voltage of the supercapacitor does not fall in the range, a high frequency load power is supplied to the grid (242); where if the terminal voltage of the supercapacitor falls within the range the high frequency power is further determined to be below 5 kW (244), where if it is below 5 kW the supercapacitor supplies actual transient power required (248), where if the high frequency power is above 5 kW the supercapacitor supplies 5kW (246); determining the average power of less than 20kW (250), determining a state of charge of the plurality of batteries for charging and discharging (252), where if the state of charge of the plurality of batteries are between 50% and 90% and the batteries in discharging mode, the batteries will be discharged (254); if the state of the battery is in charging mode, the batteries will be in idle state (255); if the state of charge of the plurality of batteries are not between 50% and 90%, the batteries will proceed with charging mode and will be idle state (256); determining the energy storage system power is equal to load power (258), where if the energy storage system power is equal to load power the second mode will proceed back to determining time is less than a maximum 86400s (204), where if the energy storage system power is not equal to the load power , the excess load power is supplied from the grid (262); and determining the energy storage system power is equal to inverter rated apparent power (260), where if the energy storage system power is equal to the inverter rated apparent power, the second mode will proceed back to determining time is less than a maximum 86400s, where if the energy storage system power is not equal to the inverter rated apparent power the inverter injects Qload within its rated apparent power(264).

10. The method (200) of claim 7, wherein determining a third mode of the energy storage system where the photovoltaic power is not available (2030) further comprising steps of: starting the grid connected mode (202); determining time is less than the maximum 86400s, where if time is more than the maximum 86400s, the time counter will reset, if time is less than a maximum 86400s, the third mode will proceed (204); activating non-peak mode from 7pm to 7am (206); determining if the terminal voltage of a supercapacitor is between a range of 34Vand 48V (266), where if the terminal voltage of the supercapacitor falls within the range, supercapacitor is charged by grid at 5 kW (368), where if the terminal voltage of the supercapacitor does not fall within the range, the third mode will proceed; determining the state of charge of the plurality of batteries for charging and discharging (270), where if the state of charge of the plurality of batteries are between 50% and 90% the the plurality of batteries are charged from grid at 0.3C and loads are supplied by the grid (272); where if the state of charge of the plurality of batteries are not between 50% and 90%, an AC/DC inverter compensates reactive power to maintain the PF at 1 and supercapacitor bank compensates real power loss of the energy and power management system (274); and proceeding back to determining time is less than a maximum 86400s (204).