CN115303082A - UAM aircraft hybrid power energy system based on microwave wireless power supply - Google Patents

Abstract

The invention relates to the technical field of UAM aircraft, in particular to a UAM aircraft hybrid power energy system based on microwave wireless power supply, which includes an energy supplement system, an energy storage system and a ground microwave power supply device; the ground microwave power supply device is used as a first energy source and when When there is surplus energy, the super capacitor and rechargeable battery are charged; the ground fast charger is used as the second energy source to charge the super capacitor and the rechargeable battery; And send the information to the energy management controller; the energy management controller controls which energy source the discharge controller uses to power the UAM aircraft; the discharge controller uses the corresponding energy source to power the UAM aircraft. The system provided by the invention effectively overcomes the problem that the UAM aircraft is limited by electric energy supply, and can effectively protect the rechargeable battery, the fuel cell and the electrical equipment of the UAM aircraft from the influence of voltage fluctuations.

Description

A hybrid power energy system for UAM aircraft based on microwave wireless power supply

technical field

The invention relates to the technical field of UAM aircraft, in particular to a UAM aircraft hybrid power energy system based on microwave wireless power supply.

Background technique

The aviation industry is in the middle of another revolution since the last century. Firstly there is growing environmental awareness driving the reduction of harmful emissions and the aviation industry's overall environmental footprint. Second, new needs and trends are currently developing toward autonomous aircraft, preparing for a future without pilots.

In recent years, with the increasing pressure of energy crisis and environmental protection, seeking innovative solutions to improve urban transportation has received a lot of attention. With the deterioration of urban traffic and air quality, in order to reduce greenhouse gas emissions, the use of clean energy is becoming popular. Air and noise pollution is one of the major drawbacks of today's aircraft, and electric aircraft solve both problems in an important way. Norway, for example, has committed to making all of its domestic flights electric by 2040. Interest in electric propulsion UAMs, especially eVTOLs, has been on the rise. UAM is an alternative mode of intra-city passenger transport that does not use any roads and is being researched and developed by the government, academia and industry. The concept of short-distance passenger air travel would introduce a more reliable, safer and greener alternative to current (air) transportation. However, the limitation of power supply greatly restricts the development of this industry. Therefore, selecting a suitable hybrid with an optimal energy management system (EMS) is crucial to achieve efficient operation of advanced UAMs.

Contents of the invention

The technical problem to be solved by the present invention is to provide a UAM aircraft hybrid power energy system based on microwave wireless power supply, which uses a variety of energy sources to form a hybrid power energy system to supply power energy for UAM aircraft, and through priority control, and can The remaining power is effectively used to meet the power required by the flight distance of the UAM aircraft to the greatest extent, which effectively overcomes the problem that the UAM aircraft is limited by the power supply, and has broad application prospects. The present invention is achieved through the following technical solutions:

A UAM aircraft hybrid power energy system based on microwave wireless power supply, which includes an energy supplement system, an energy storage system and ground microwave power supply equipment;

The energy supplement system includes a wireless charger, a ground fast charger and a charging controller connected to the wireless charger and the ground fast charger respectively;

The energy storage system includes a supercapacitor, a rechargeable battery, an energy management controller, and a discharge controller;

The charging controller is respectively communicated with the energy management controller and the discharge controller, and the supercapacitor and the rechargeable battery are respectively communicated with the energy management controller and the discharge controller;

The ground microwave power supply equipment is a wireless charger that charges through microwaves as the first energy source for the power energy supply when the UAM aircraft is flying, and when there is a surplus of energy, the supercapacitor and the rechargeable battery are charged when the state of charge is low. Charge;

The ground fast charger is responsible for the power supply of the UAM aircraft when it is on the ground, charging the supercapacitor and the rechargeable battery, as a second energy source for the power energy supply of the UAM aircraft during flight;

The charging controller is responsible for controlling the charging and discharging of wireless charging and ground fast chargers, the sequence of releasing energy from wireless chargers, supercapacitors and rechargeable batteries, and sending corresponding energy information to the energy management controller;

The energy management controller controls which energy source the discharge controller uses to supply power to the UAM aircraft according to the energy information of the charge controller and the discharge controller;

The discharge controller uses a corresponding energy source to supply power to the UAM aircraft according to the energy information of the energy management controller. Further, the energy storage system also includes a fuel cell, the fuel cell communicates with the discharge controller, and through the discharge controller, together with the supercapacitor and the rechargeable battery, it is used as a second energy source for the UAM aircraft to supply electric energy when it is flying in the air.

Further, when the fuel cell, the supercapacitor and the rechargeable battery are used as the second energy source for the power energy supply of the UAM aircraft during flight, its output priority is lower than that of the supercapacitor and the rechargeable battery.

Furthermore, when the ground microwave power supply equipment is a wireless charger that charges through microwaves for the power energy supply of the UAM aircraft when it is flying, and when there is a surplus of energy, the supercapacitor is charged first, and the supercapacitor is charged when it reaches a high charging state. Charging batteries.

Optimally, the wireless charger includes a receiving antenna and a rectification circuit, and the rectification circuit includes a low-pass filter, a matching circuit and a pass-through filter connected in sequence.

Further, the energy management controller includes an energy management main controller, a plurality of converter controllers, and a monitoring controller. The energy management main controller receives the charging and discharging information of the charging controller and the discharging controller and calculates the power reference through EMS. The signal is sent to the corresponding converter controller, and the converter controller decouples the power reference signal into a reference voltage signal and a current signal, and the monitoring controller controls the DC/DC conversion of the corresponding energy source respectively, and adjusts each energy source to the DC bus voltage and current.

Further, the voltage and current from each energy source to the DC bus directly supply power to the DC load of the UAM aircraft, and after DN/AC conversion, supply power to the AC electrical equipment of the UAM aircraft through the AC bus.

Beneficial effects of the present invention:

A UAM aircraft hybrid power energy system based on microwave wireless power supply provided by the present invention has the following advantages:

1. Using a variety of energy sources to form a hybrid electric energy system to supply UAM aircraft with electrical energy can meet the electrical energy required by UAM aircraft for long-distance flight and overcome the shortcoming of UAM aircraft being limited by electrical energy.

2. By setting the priority of multiple energy sources, charging by microwave as the first energy source can not only meet the needs of UAM aircraft flight, but also greatly preserve the strength of the hybrid electric energy system, and when there is a surplus in microwave discharge, The remaining energy can also charge the supercapacitor and rechargeable battery, which further improves the endurance of the UAM aircraft.

3. By setting the energy management main controller, multiple converter controllers and monitoring controllers for the energy management controller, the structure is clear and reliable, and the online adjustable power distribution between different energy sources is realized, and the UAM is improved as much as possible. It can effectively protect the rechargeable battery, fuel cell and UAM aircraft electrical equipment from the influence of voltage fluctuations.

Description of drawings

Fig. 1 is a schematic structural diagram of the system of the present invention;

Fig. 2 is a schematic structural diagram of a wireless charger;

Fig. 3 is a schematic diagram of the control flow of the energy management controller.

Detailed ways

A UAM aircraft hybrid power energy system based on microwave wireless power supply, as shown in Figure 1, it includes an energy supplement system, an energy storage system and ground microwave power supply equipment;

The energy supplement system includes a wireless charger, a ground fast charger and a charging controller connected to the wireless charger and the ground fast charger respectively;

The energy storage system includes a supercapacitor, a rechargeable battery, an energy management controller and a discharge controller, and the rechargeable battery is preferably a lithium polymer battery;

The charging controller is respectively communicated with the energy management controller and the discharge controller, and the supercapacitor, the rechargeable battery and the fuel cell are respectively communicated with the energy management controller and the discharge controller;

The ground microwave power supply equipment is a wireless charger that charges through microwaves as the first energy source for the power energy supply when the UAM aircraft is flying, and when there is a surplus of energy, the supercapacitor and the rechargeable battery are charged when the state of charge is low. Charge;

The ground fast charger is responsible for the power supply of the UAM aircraft when it is on the ground, charging the supercapacitor and the rechargeable battery, as a second energy source for the power energy supply of the UAM aircraft during flight;

The charging controller is responsible for controlling the charging and discharging of wireless charging and ground fast chargers, the sequence of releasing energy from wireless chargers, supercapacitors and rechargeable batteries, and sending corresponding energy information to the energy management controller;

The energy management controller controls which energy source the discharge controller uses to supply power to the UAM aircraft according to the energy information of the charge controller and the discharge controller; the main electrical equipment of the UAM aircraft includes a control system and a propulsion system. The discharge controller uses a corresponding energy source to supply power to the UAM aircraft according to the energy information of the energy management controller. UAM (Urban Air Mobility) is a safe and efficient air transportation system that will use highly automated aircraft to operate and transport passengers or cargo at low altitudes in cities and suburbs. The system generally uses new energy as the power of the aircraft, and can provide a "three-dimensional traffic" solution for urban traffic. "End-to-end" logistics transportation and passenger flights between different nodes are realized by setting up different short-distance/vertical take-off and landing fields. UAM will consist of an ecosystem that considers the evolution and safety of aircraft, operational framework, airspace Income, infrastructure development and community participation, but at present, power energy supply is a short board restricting its development.

However, this application adopts a hybrid power energy system, including wireless microwave power supply, supercapacitor, rechargeable battery and other hybrid power supply. Among them, wireless power supply is a technology that transfers power energy from a power generating device or a power supply end to a power receiving device without an electrical conductor. Wireless power transfer is a general term that can be achieved using a number of different technologies, including electric fields, magnetic fields, and electromagnetic waves. The transmitter converts electrical energy into the energy state of the corresponding field, and after transmission through a space, it is received by one or more receivers and converted back into electrical energy.

Wireless energy transfer technologies fall into two categories: non-radiative and radiative. Non-radiative technology uses inductive coupling between coils, and energy is transmitted through a magnetic field. Radiation technology uses microwave, laser and other directed energy beams to transmit energy. This technology can be transmitted to a longer distance, but the transmitting party must aim at the receiving party to transmit. This application uses microwave wireless technology, which can be directed to charge the UAM aircraft. Realize the long-distance flight of UAM aircraft.

Supercapacitors have higher specific power and lower specific energy. Due to their fast response to peak power, supercapacitors are best suited to handle sudden transients on the time scale of seconds. This can be great for takeoff and landing phases. In addition, they indirectly protect the fuel cell, rechargeable battery and DC bus. It can absorb DC bus voltage fluctuations, prolong the life of rechargeable batteries and fuel cells, and protect the main electrical equipment of UAM aircraft from the impact of voltage fluctuations.

Rechargeable batteries have relatively high specific energy and specific power. Batteries used on UAMs come in many different technologies, Lithium-polymer (Li-Po) and Lithium-ion (Li-ion) batteries are better suited for applications with long-term changes in the range of minutes to hours due to their high performance. However, the battery alone may not allow the UAM to perform some maneuvers that require very fast power response, in which case a supercapacitor is a good choice to balance the limitations of the charged battery.

Therefore, through the combination of the above-mentioned energy sources, the electric energy required for the long-distance flight of the UAM aircraft can be met, and the shortcoming of the UAM aircraft being limited by the electric energy can be overcome.

And wireless microwave power supply is preferred as the first energy source, which can not only meet the needs of UAM aircraft flight, but also greatly preserve the strength of the hybrid electric energy system, and when there is a surplus in microwave discharge, the remaining energy can also be used for supercapacitors, rechargeable batteries Charging further improves the endurance of the UAM aircraft, and the supercapacitor and the rechargeable battery are also used as the second energy source to help improve the life of the rechargeable battery.

Further, the energy storage system also includes a fuel cell, the fuel cell communicates with the discharge controller, through the discharge controller control together with the supercapacitor and the rechargeable battery as the second energy source for the power energy supply of the UAM aircraft when flying in the air, the fuel The battery is preferably a hydrogen fuel cell.

The hybrid electric energy system sets a fuel cell together with a supercapacitor and a rechargeable battery as the second energy source for the power energy supply of the UAM aircraft when it is flying in the air, which further improves the capability of the UAM aircraft hybrid electric energy system and provides UAM aircraft with long-distance Range is guaranteed, and the supercapacitor absorbs DC bus voltage fluctuations, extending the life of the fuel cell.

The fuel cell is preferably a hydrogen fuel cell. A fuel cell is a power generation device that converts chemical energy in fuel into electrical energy through oxidation-reduction reactions mainly through oxygen or other oxidants. The most common fuel is hydrogen. Hydrogen fuel cells are characterized by high specific energy and low specific power. The energy density of this fuel is usually five times higher than that of lithium polymer batteries. However, one of the main well-known problems of fuel cells is the slow dynamic response due to the hydrogen delivery system. For this reason, fuel cells are suitable for low-speed long-endurance UAMs. This is great for cruising and descending periods. In addition, the fuel cell can use excess energy to charge the rechargeable battery during the cruise phase.

Further, when the ground microwave power supply equipment is a wireless charger that charges through microwaves as the first energy source for power energy supply when the UAM aircraft is flying, and when there is a surplus of energy, the supercapacitor is preferentially charged, and when the supercapacitor is charged to a high charge state and then charge the rechargeable battery. Set the charging priority and give priority to ensuring that the supercapacitor is fully charged, so as to avoid the impact of the DC bus voltage fluctuation on the electrical equipment, rechargeable battery and fuel cell when the UAM aircraft is flying in the air, especially during the take-off and landing phases.

Optimally, the wireless charger includes a receiving antenna and a rectification circuit, and the rectification circuit includes a low-pass filter, a matching circuit, and a pass-through filter connected in sequence, and its structure is shown in Figure 2.

The ground microwave power supply equipment includes a microwave transmitter, and the microwave transmitter transmits microwaves to the UAM aircraft through a wireless charger when the UAM aircraft is flying. The wireless charger has an embedded microwave receiver that converts microwaves into electricity to power the UAM aircraft. This technology enables UAM vehicles to stay in flight for longer periods of time with fewer landings to recharge rechargeable batteries and increase range. When recharging is required, the UAM vehicle joins the air power link area to receive energy. Thus, safety is improved by reducing take-off and landing risks. Microwave transmitters are deployed on the roofs of high-rise buildings to avoid obstruction to microwaves, or on mobile stations to establish radiative links between UAM vehicles and the nearest energy source for rapid power transfer.

Further, the energy management controller includes an energy management main controller, a plurality of converter controllers, and a monitoring controller. The energy management main controller receives the charging and discharging information of the charging controller and the discharging controller and calculates the power reference through EMS. The signal is sent to the corresponding converter controller, and the converter controller decouples the power reference signal into a reference voltage signal and a current signal, and the monitoring controller controls the DC/DC conversion of the corresponding energy source respectively, and adjusts each energy source to the DC bus voltage and current.

From the power demand analysis of different phases of UAM aircraft flight, it can be known that in the take-off and climb phase, the load power is the largest, and the load peak power exceeds the maximum power of each source. Therefore, the load power of these stages must be shared by all energy sources simultaneously. The next level of power demand occurs in the descent and landing phases, with large fluctuations, and the load power in the cruising phase is at a low and stable level. In the traditional passive control method, the power output of each energy source depends on its own power characteristics, the energy loss is serious, and the safety is low. However, this system performs EMS and management through the main energy management controller, and distributes power in an active way. Consumption economy, efficiency and flight time can be further optimized.

The EMS calculation follows the following principles:

(i) The wireless charger discharges preferentially. The wireless charger always works at the maximum power point to provide as much energy as possible for the flight.

(ii) Supercapacitors, rechargeable batteries cooperate with wireless chargers and fuel cells to make up for excess power demand. Supercapacitors, rechargeable batteries are also responsible for sharp fluctuations in power demand and peak power demand. Supercapacitors, rechargeable batteries can be charged at limited charge rates by wireless chargers and fuel cells.

(iii) Fuel cells have the lowest output priority to save fuel and extend battery life.

(iv) The required power of the DC bus is always satisfied by four energy sources, as shown in equation (1):

P _load =P _mp +P _bat +P _uc +P _fc (1)

where P _load is the DC power demand, and P _mp , P _bat , P _uc and P _fc are the power extracted from the wireless charger, rechargeable battery, supercapacitor and fuel cell, respectively.

The energy management controller can use FSM (a strategy combining fuzzy logic control algorithm and state machine strategy) for computational control to enhance the online potential and adaptability of the energy management strategy. The specific implementation process is shown in Figure 3.

P _load is used as the required power of the DC bus, which can be calculated using the formula (2):

P _load ＝I _bus U _bus ＝I _bus U _bat , (2)

Among them, I _bus is the current through the DC bus, and U _bus is the voltage of the DC bus. They are both measured by busbar CV sensors. U _bus is equal to the rechargeable battery voltage U _bat , since the rechargeable battery is connected directly in parallel on the DC bus.

The FSM strategy used to determine the output of each energy source has the following six states:

State one: the maximum available power (P _mpMax ) of the wireless charger is higher than the required power (P _load ). This means that the remaining demanded power (P _rd ) is negative. Supercapacitors and batteries with a high state of charge do not need to be charged, and a separate wireless charger is selected to meet the power demand.

State 2: The wireless charger has the ability to meet the power demand, while the charging state of the supercapacitor is high, the redundant power used by the wireless charger to charge the rechargeable battery is lower than the maximum charging power (Pc) of the rechargeable battery, and then the wireless charger outputs its maximum power to meet demand power and charge the rechargeable battery.

State 3: The maximum power of the wireless charger is higher than the sum of the required power (P _load ) and the maximum charging power of the rechargeable battery (Pc), and the charging state of the supercapacitor is high, then the output power of the wireless charger is equal to the sum of the power. State four: The wireless charger has the capacity to meet the power demand while the supercapacitor state of charge is low, then the wireless charger outputs its maximum power to meet the demand power and charge the supercapacitor.

State 5: The wireless charger cannot meet the power demand alone. In order to save fuel, the wireless charger provides the maximum power, and then uses the fuzzy logic control algorithm to determine the desired output fuel cell power P _fo and rechargeable battery power P _bo . At this time, the expected output power P _uo of the supercapacitor is the difference between the fuel cell P _fo and the rechargeable battery P _bo and the remaining required power (P _rd ). If P _uo is negative, the fuel cell and rechargeable battery will charge the supercapacitor after meeting the remaining required power.

State six: the wireless charger runs at the maximum available power, and P _uo is positive, then the supercapacitor, together with the fuel cell and the rechargeable battery, can meet the remaining power demand.

From state one to state four, the EMS only uses the state machine strategy to handle the output power of the wireless charger, rechargeable battery and supercapacitor. The last two states are combined with a fuzzy logic control strategy to control the output power of the fuel cell, supercapacitor and rechargeable battery.

Through the above control, the online adjustable power distribution between different energy sources is realized, the endurance of the UAM aircraft is improved as much as possible, and the fluctuation of the DC bus voltage is absorbed by the supercapacitor, which can prolong the life of the rechargeable battery and the fuel cell.

Further, the voltage and current from each energy source to the DC bus directly supply power to the DC load of the UAM aircraft, and after DN/AC conversion, supply power to the AC electrical equipment of the UAM aircraft through the AC bus. In this way, after the online adjustable power distribution between different energy sources, the UAM aircraft electrical equipment is powered through the DC bus and the AC bus. Since the fluctuation of the DC bus voltage is absorbed by the super capacitor, the UAM aircraft electrical equipment can be slowed down. Voltage fluctuations further protect the electrical equipment of UAM aircraft.

To sum up, the UAM aircraft hybrid electric energy system based on microwave wireless power supply protected by the present invention adopts multiple energy sources to form a hybrid electric energy system to supply electric energy for UAM aircraft, and through priority control, And it can make effective use of the remaining power to maximize the power required by the flight distance of UAM aircraft, effectively overcome the problem of UAM aircraft being limited by power energy supply, and can effectively protect rechargeable batteries, fuel cells and UAM aircraft electrical equipment It is free from the influence of voltage fluctuation and has wide application prospects. The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (9)

1. A UAM aircraft hybrid power energy system based on microwave wireless power supply, characterized in that: comprise energy supplement system, energy storage system and ground microwave power supply equipment; The energy supplement system includes a wireless charger, a ground fast charger and a charging controller connected to the wireless charger and the ground fast charger respectively; The energy storage system includes a supercapacitor, a rechargeable battery, an energy management controller, and a discharge controller; The charging controller is respectively communicated with the energy management controller and the discharge controller, and the supercapacitor and the rechargeable battery are respectively communicated with the energy management controller and the discharge controller; The ground microwave power supply equipment is a wireless charger that charges through microwaves as the first energy source for the power energy supply when the UAM aircraft is flying, and when there is a surplus of energy, the supercapacitor and the rechargeable battery are charged when the state of charge is low. Charge; The ground fast charger is responsible for the power supply of the UAM aircraft when it is on the ground, charging the supercapacitor and the rechargeable battery, as a second energy source for the power energy supply of the UAM aircraft during flight; The charging controller is responsible for controlling the charging and discharging of the wireless charging and the ground fast charger, as well as the sequence of releasing energy from the energy source, and sending the corresponding energy information to the energy management controller; The energy management controller controls which energy source the discharge controller uses to supply power to the UAM aircraft according to the energy information of the charge controller and the discharge controller; The discharge controller uses a corresponding energy source to supply power to the UAM aircraft according to the energy information of the energy management controller. 2. A kind of UAM aircraft hybrid electric energy system based on microwave wireless power supply according to claim 1, it is characterized in that, described energy storage system also comprises fuel cell, and described fuel cell is communicated with discharge controller, through discharge control The controller, together with the supercapacitor and the rechargeable battery, are used as the second energy source for the power energy supply of the UAM aircraft during flight. 3. A kind of UAM aircraft hybrid power energy system based on microwave wireless power supply according to claim 1 or 2, characterized in that the wireless charger is charged by microwaves as the power energy supply when the UAM aircraft flies, when there is a surplus of energy When charging, the supercapacitor is charged first, and the rechargeable battery is charged after the supercapacitor is charged to a high state of charge. 4. The UAM aircraft hybrid power energy system based on microwave wireless power supply according to claim 1 or 2, wherein the rechargeable battery is a lithium polymer battery. 5. A UAM aircraft hybrid electric energy system based on microwave wireless power supply according to claim 2, wherein the fuel cell is a hydrogen fuel cell. 6. A kind of UAM aircraft hybrid power energy system based on microwave wireless power supply according to claim 2, is characterized in that, fuel cell is used as the second energy source together with supercapacitor, rechargeable battery for the electric power when UAM aircraft flies in the air When energy is replenished, its output priority is lower than that of supercapacitors and rechargeable batteries. 7. A kind of UAM aircraft hybrid power energy system based on microwave wireless power supply according to claim 1 or 2, characterized in that, the wireless charger includes a receiving antenna and a rectifying circuit, and the rectifying circuit includes sequentially connected low pass filter, matching circuit and pass filter. 8. A kind of UAM aircraft hybrid power energy system based on microwave wireless power supply according to claim 1 or 2, characterized in that, the energy management controller includes an energy management main controller, a plurality of converter controllers and monitoring controller, the energy management main controller receives the charging and discharging information of the charging controller and the discharging controller and calculates the power reference signal through EMS and sends it to the corresponding converter controller, and the converter controller decouples the power reference signal into Referring to the voltage signal and current signal, the monitoring controller controls the DC/DC conversion of the corresponding energy source respectively, and adjusts the voltage and current from each energy source to the DC bus. 9. A kind of UAM aircraft hybrid power energy system based on microwave wireless power supply according to claim 8, characterized in that, the voltage and current from each energy source to the DC bus directly supply power to the UAM aircraft DC load, and through DN/AC After conversion, power is supplied to the AC electrical equipment of the UAM aircraft through the AC bus.

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