CN103346612B - 336VDC DC UPS system and method for supplying power to - Google Patents

Abstract

The present invention proposes a 336VDC DC uninterruptible power supply system and a power supply method. A 24-pulse main transformer rectifier is used to convert the mains AC power supply into a 336VDC DC power supply as the main power supply of the system; The charging and maintenance of the battery pack is used as the emergency backup power supply of the system; the high-speed DC static switch module determines the high-speed switching of the power load from the main circuit of the mains power supply or the emergency backup power supply according to the quality of the mains power; so that it can be the original three-phase IT communication equipment, switching equipment, computer instrument control devices and lighting equipment, etc. powered by AC provide uninterrupted power supply. The backup battery pack of the present invention is in the state of charging and maintenance at ordinary times, and is only activated when the system is powered by emergency, which increases the use of storage batteries. The life span improves the reliability and fault tolerance of the system. The 24-pulse main transformer rectifier can greatly reduce the harmonic current injection of the system to the grid side, which meets the relevant national standards.

Description

336VDC DC uninterruptible power supply system and power supply method

technical field

The invention relates to the technical field of power supplies, in particular to a 336VDC uninterruptible power supply system and a power supply method.

Background technique

Due to the unique shortcomings of UPS itself, it is determined that the safe power supply of the telecommunication system and the guarantee requirements of important automatic instruments and meters, DCS, and SIS cannot be fully guaranteed. Its relatively frequent self-failures bring accidents to the system operation in an endless stream, which brings great harm to the enterprise society. There have been many negative impacts and economic losses.

Among the current existing technical solutions, a typical 336V DC power supply system is shown in Figure 1, including n parallel high-voltage DC switching power supplies 101, which convert the input AC power into high-voltage DC power; the high-voltage DC power distribution panel 102 integrates and distribution of high-voltage DC power supply, using high-voltage DC switching power supply 101 and battery 103 as input, the positive and negative poles are respectively distributed through fuses, and output to the integrated pallet high-voltage DC control unit 104 where IT equipment 105 is installed; the battery 103 is normal in the AC power supply When the high-voltage DC switching power supply 101 is used for floating charging, when the AC power supply fails, it will automatically provide power to the IT equipment to keep the power supply of the IT equipment uninterrupted; the integrated pallet high-voltage DC control unit 104 is connected with each The IT equipment 105 is connected as the IT equipment 105 power input on/off control device and overload protection device.

However, the main technical feature of this technical solution is that the DC power distribution panel 102 and the storage battery 103 adopt a parallel structure, so this solution has the following defects:

1. The high-voltage DC switching power supply 101 needs complex control and management functions to ensure the floating charging voltage of multiple batteries 103, which not only increases the burden on the system, but also greatly reduces the fault tolerance of the system.

2. When the mains power is normal, the high-voltage DC switching power supply 101 not only needs to undertake the task of supplying power to IT equipment loads, but also charges and maintains the battery 103 at the same time, which greatly reduces the service life of the battery and reduces the reliability of the system

Contents of the invention

In order to solve the above problems, the object of the present invention is to provide a 336VDC DC uninterruptible power supply system, which not only prolongs the service life of the battery, improves the reliability and fault tolerance of the system, but also complies with the national standard of grid side technical indicators, and can Replace the existing three-phase output AC uninterruptible power supply system (UPS).

The 336VDC DC uninterruptible power supply system is used to convert the high-voltage AC power input by the mains into a DC power with a nominal voltage of 336VDC, and supplies power to IT and similar equipment in the communication room with three-phase AC input. It is characterized in that it includes:

The main transformer rectifier is used to convert the three-phase AC power input from the mains into 336VDC DC;

The high-frequency switching precision charger is connected with a backup battery pack, which is used to convert the high-voltage AC power input from the mains into 336VDC DC power and store it in the backup battery pack as a system backup power supply;

The high-speed DC static switch is used as a redundant connection bridge between the mains power supply and the backup power supply. When the 336VDC main power supply is supplied, the high-speed DC static switch is blocked, and the main circuit of the system is powered by the mains after transformation and rectification. When the mains supply fails, the system load is switched to the backup power supply through the high-speed DC static switch to ensure the uninterrupted operation of the power load connected to the system.

The main transformer rectifier adopts a 24-pulse rectifier.

The high-speed DC static switch is connected with a control circuit, and the control circuit monitors the mains input voltage and the DC voltage after transformation and rectification in real time.

Battery maintenance including high frequency switching precision chargers in at least N+1 redundant configuration as backup power.

When the high-speed DC static switch is triggered, the system power supply is transferred to the backup power supply. At the same time, the high-frequency switching precision charger sleeps.

The present invention also includes a 336VDC DC uninterrupted power supply method, the method comprising the following steps:

A. Convert the high-voltage AC power input from the mains into 336VDC DC and perform harmonic rectification processing. After processing, it is input into the main circuit for power supply, and converted into 336VDC DC all the way and stored in the backup battery pack;

B. Detect the voltage of the main circuit. When the low voltage of the main circuit is detected, switch to the backup battery pack to supply power and stop the charging of the backup battery pack. When the main circuit voltage is detected to return to normal, the main circuit of the system returns to the state after the transformer and rectifier mains power supply.

The harmonic rectification process adopts at least 24-pulse harmonic rectification technology to reduce harmonic current injection into the grid.

The backup battery set includes N+1 backup batteries as redundancy.

In addition, a high-speed DC static switch is adopted, and the high-speed DC static switch can switch the main circuit to the backup power supply at a high speed, and the static switch can be blocked in time after the mains power is restored.

A new type of 336VDC industrial frequency transformer DC uninterruptible power supply system and power supply method provided by the present invention adopts a 24-pulse main transformer rectifier to convert the mains AC power supply into a 336VDC DC power supply as the main power supply of the system; the high-frequency switch of the system is precise The charging and maintenance of the system backup battery pack by the charger is used as the system emergency backup power supply. The high-speed DC static switch device determines the high-speed switching of the power load from the main circuit of the mains power supply or the emergency backup power supply according to the quality of the mains power; so that it can Provide uninterrupted power supply for the original three-phase AC power supply IT communication equipment, switching equipment, computer instrument control devices and lighting equipment. The service life of the battery is extended, and the reliability and fault tolerance of the system are improved. The main transformer rectifier can greatly reduce the harmonic current injection of the system to the grid side, which meets the relevant national standards.

Description of drawings

Fig. 1 is a system structure frame diagram of the prior art.

Fig. 2 is a system structure frame diagram of the present invention.

FIG. 3 is a system circuit structure diagram of an embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings of specific embodiments.

The design idea of the present invention is to break through the limitations of the original mains DC power supply system. As shown in Figure 1, in the prior art mains DC power supply system, the power supply main circuit and the battery 103 adopt a parallel structure, and all batteries need to be All put into operation. The high-voltage DC switching power supply 101 not only needs to supply power to the connected load electrical equipment, but also needs to charge and maintain the storage battery 103, which is difficult to balance. At the same time, the high-voltage DC switching power supply 101 simultaneously controls multiple battery packs to carry out equalization and floating charging, which will easily reduce the service life of the batteries, and the reduced reliability of the batteries will also greatly increase the risk of normal operation of the backup power supply.

As shown in Figure 2, the main technical frame of a kind of 336VDC high voltage DC power supply system provided by the present invention includes:

The main transformer rectifier 201 is used to convert the high-voltage AC power input by the mains into 336VDC DC.

The high-frequency switching precision charger 202 is connected with a backup battery pack 204, which is used to convert the high-voltage AC power input from the mains into 336VDC DC power and store it in the backup battery pack 204 as a system backup power supply.

The high-speed DC static switch 203 is connected to the main circuit and the backup power supply. When the main transformer rectifier 201 works normally and outputs a DC power of 336VDC, the high-speed DC static switch 203 is blocked, and the DC power of the main circuit is directly output to loads such as IT and communication room equipment. Power supply; when the mains supply fails or the main transformer rectifier 201 is not working normally, trigger the high-speed DC static switch 203 to switch the backup power supply to the load equipment for power supply, ensuring uninterrupted power supply for IT and communication room settings.

As an embodiment, Fig. 3 is a system circuit structure diagram of the present invention, as shown in the figure, when the mains power supply is normal, the system directly converts the high-voltage AC power into 336VDC direct current through the main transformer rectifier 201 and inputs it into the main circuit as The communication equipment is powered, and the system is equipped with a surge protection circuit 207 at the same time.

The main transformer rectifier 201 includes a D-D/Y transformer 205 and the 24-pulse rectifier 206 also includes a balancing reactor. The total distortion THD parameter can be further reduced to less than 10%, and the actual measurement can reach less than 5% under the condition of full load of the system power supply, and the actual measurement of the system efficiency can reach 96%, which is completely satisfactory.

China Mobile's QB-H-008-2012 "336V DC Power Supply System" and QB-H-007-2012 "336V Switching Rectifier" standards are superior to the existing mains DC power supply technology especially in terms of reliability indicators.

As an embodiment, the DC static switch 203 of the present invention adopts a thyristor SCR (hereinafter referred to as SCR) switch structure. Based on the SCR high-speed DC static switch 203, its complexity is much smaller than that of the UPS static switch. Since there is no requirement for system synchronization, it can be achieved Very high low voltage monitoring judgment and switching response speed. In order to improve the reliability of the system, a high-speed DC static switch 203 can also be used in parallel with the control circuit structure. The control circuit monitors the mains input voltage and the DC voltage after transformation and rectification in real time. When the control circuit detects low voltage in the main circuit, it triggers the SCR and turns off the high-frequency switch precision charger 202 at the same time. When the utility power is restored, the high-speed DC static switch cancels the trigger current. SCR is blocked immediately. The high-frequency switching precision charger 202 starts up gradually to resume charging.

The switching delay time of the high-speed DC static switch 203 is ton<0.05mS, and the recovery time is not required. Due to the current development of the big data cloud platform, large-capacity IT and communication equipment all use AC three-phase AC power supply, and the time constant of the filter capacitor of the switching regulated power supply and the full-load support system of the inductive energy storage are both >0.1mS, so the high-speed DC The switching of the static switch 203 can fully meet the requirements of the system for uninterrupted power supply.

The configuration of the high-frequency switching precision charger 202 and the backup battery pack 204 follows the N+1 principle. The system adjusts the number of activated high-frequency switching precision chargers 202 as required. When the series is switched to the backup power supply and the backup battery pack 204 discharges deeply, the system opens all high-frequency switch precision chargers 202 to charge the backup battery pack 204; when the backup power supply is in standby mode, the high-frequency switch precision charger 202 The charging current is small, especially in the floating charging state, the system only needs to start a high-frequency switching precision charger 202 to charge the backup battery pack 204; when the backup battery pack 204 is fully charged, the high-frequency switching precision charger 202 stops working. In actual use, since the probability of mains supply failure is very low, the high-frequency switch precision charger 202 is in the standby and floating charging state almost accounting for more than 95%. Compared with the prior art, the battery life is greatly increased. In order to facilitate management, the high-frequency switching precision charger 202 adopts a 24-hour automatic switching working system, and immediately starts the next high-frequency precision charger 202 when a fault occurs. Each high-frequency switching precision charger 203 is connected with an isolation diode to ensure the unidirectional output of the charger current. Schottky diodes are used to isolate and connect each battery pack, so that multiple battery packs running in parallel will not interfere with each other.

It will be understood by those of ordinary skill in the art that various substitutions, modifications and changes in form and details may be made without departing from the spirit and scope of the present invention as defined by the claims. Therefore, it will be understood that the above-described embodiments are for illustrative purposes only, and are not to be construed as limiting the present invention.

Claims (1)

1. A 336VDC DC uninterruptible power supply system, which is used to convert the high-voltage AC power input of the three-phase mains power supply into a DC power with a nominal voltage of 336VDC, for the IT and communication room equipment powered by the original three-phase AC power supply, characterized in that ,include: Main transformer rectifier, the main transformer rectifier adopts a rectifier with at least 24 pulses, which is used to convert the three-phase AC power input from the mains into 336VDC direct current; The high-frequency switching precision charger is connected with a backup battery pack, which is used to convert the high-voltage AC power input from the mains into 336VDC DC power and store it in the backup battery pack as a system backup power supply; The high-speed DC static switch is used as a redundant connection bridge between the mains power supply and the backup power supply. When the main power supply is 336VDC, the high-speed DC static switch is blocked. When a failure occurs, the system load is switched to the backup power supply through a high-speed DC static switch to ensure uninterrupted operation of the power load connected to the system; The high-speed DC static switch is connected with a control circuit, and the control circuit monitors the mains input voltage and the DC voltage after transformation and rectification in real time; At least N+1 redundant high-frequency switching precision chargers are used as battery pack maintenance for backup power; When the high-speed DC static switch is not triggered, the high-frequency switch precision charger is in the charging state; When the high-speed DC static switch is triggered, the system power supply is transferred to the backup power supply, and the high-frequency switch precision charger is dormant at the same time; The working process of 336VDC DC uninterruptible power supply system is as follows: A. Convert the high-voltage AC power input from the mains into 336VDC DC and perform harmonic rectification processing. The harmonic rectification processing uses at least 24 pulses of harmonic rectification technology. After processing, it is input into the main circuit for power supply and converted all the way The direct current of 336VDC is stored in the backup battery pack; B. Detect the voltage of the main circuit. When the low voltage of the main circuit is detected, switch to the backup battery pack to supply power and stop the charging of the backup battery pack. When the main circuit voltage is detected to return to normal, the main circuit of the system returns to the state after the transformer and rectifier mains power supply.