High-voltage energy storage frequency converter system

Abstract

The invention discloses a high-voltage energy storage frequency converter system which is used for solving the problems that an existing frequency converter is difficult to realize power failure to keep load operation, or the implementation mode is complicated and the cost is relatively high. The high-voltage energy storage frequency converter system comprises a high-voltage frequency converter and a battery cluster; the high-voltage frequency converter comprises a phase-shifting transformer, a controllable rectification inversion unit and a power unit, the phase-shifting transformer is respectively connected with the controllable rectification inversion unit and the power unit; the controllable rectification inversion unit is also connected with the battery cluster; the other end of the high-voltage frequency converter is connected with a load; when the power supply normally supplies power, the high-voltage frequency converter transmits current of the power supply to the load and charges the battery cluster, and when the power supply is cut off, the high-voltage frequency converter inverts direct current of the battery cluster into alternating current through the controllable rectification inversion unit, transmits the alternating current to the phase-shifting transformer and supplies the alternating current to the load through the controllable rectification inversion unit and the power unit. The system can guarantee continuous operation of the load during power failure, and is simple in structure and low in cost.

Description

Technical Field

[0001] The present application relates to the field of variable frequency power supply, and in particular to a high voltage energy storage inverter system. Background Art

[0002] With the continuous upgrading of electrification and automation capabilities, the power supply requirements for important loads in the power supply system are becoming higher and higher. The power supply system is required to be able to continuously supply power to the load and ensure long-term continuous operation of the load even in the event of a power outage.

[0003] Moreover, in many power supply systems, due to the large power of the motor, frequency conversion is usually used for power supply, such as the fan load in the coal industry. The important loads in the power supply system are driven by the frequency converter, which is conducive to reducing the energy consumption of the equipment and improving production efficiency and safety.

[0004] However, traditional frequency converters do not have the ability to keep the load running during power outages, or the implementation method is complex and costly. Summary of the invention

[0005] The embodiments of the present application provide a high-voltage energy storage inverter system to solve the problem that existing inverters are difficult to maintain load operation during power outages, or the implementation method is complex and costly.

[0006] A high-voltage energy storage inverter system provided in an embodiment of the present application includes a high-voltage inverter and a battery cluster; The high-voltage frequency converter includes a phase-shifting transformer, a connected controllable rectifier inverter unit and a power unit; The phase-shifting transformer is connected to the controllable rectifier inverter unit and the power unit respectively; The controllable rectifying and inverting unit is also connected to the battery cluster; One end of the high-voltage inverter is connected to a power source, and the other end is connected to a load; when the power source is supplying power normally, the high-voltage inverter transmits the current of the power source to the load and charges the battery cluster; when the power source is cut off, the high-voltage inverter inverts the direct current of the battery cluster into alternating current through the controllable rectifier inverter unit, transmits it to the phase-shifting transformer, and supplies the load through the controllable rectifier inverter unit and the power unit.

[0007] In one example, the high-voltage inverter includes a plurality of parallel transmission branches, each of the transmission branches includes the controllable rectifier inverter unit and at least one of the power units, and each of the transmission branches is connected to the load.

[0008] In one example, the capacity of the winding in the phase-shifting transformer connected to the controllable rectifier inverter unit is determined based on the capacity of the battery cluster and the number of the controllable rectifier inverter units, and is negatively correlated with the number of the controllable rectifier inverter units.

[0009] In one example, the controllable rectifier inverter unit is arranged at a star-blocking point of the high-voltage inverter.

[0010] In one example, the controllable rectifier inverter unit is connected to the corresponding winding in the phase-shifting transformer through a filter reactor.

[0011] In one example, the battery cluster includes a plurality of battery packs, fuses, and battery contactors connected in sequence; when the battery contactor is closed, the battery cluster is connected to a circuit where a controllable rectifier inverter unit is connected.

[0012] In one example, the battery cluster further includes a battery management system, which controls the battery contactor to be disconnected when a fault of the battery pack is detected.

[0013] In one example, the frequency converter further includes an input contactor, a buffer contactor, and a buffer resistor; The buffer contactor is connected to the buffer resistor, one end of the input contactor is connected to the buffer contactor, and the other end is connected to the buffer resistor.

[0014] In one example, the topological structure of the power unit is a two-quadrant or a four-quadrant structure.

[0015] In one example, the topological structure of the connection between the controllable rectifier inverter unit and the battery cluster includes: The first insulated gate bipolar transistor Q1 and the second insulated gate bipolar transistor Q2, the third insulated gate bipolar transistor Q3 and the fourth insulated gate bipolar transistor Q4, the fifth insulated gate bipolar transistor Q5 and the sixth insulated gate bipolar transistor Q6 are connected in series respectively, the middle point of the series connection of the first insulated gate bipolar transistor Q1 and the second insulated gate bipolar transistor Q2 is connected to the first end of the three-phase input terminal through the first fuse Fu1 and the first reactor L1, the middle point of the series connection of the third insulated gate bipolar transistor Q3 and the fourth insulated gate bipolar transistor Q4 is connected to the first end of the three-phase input terminal through the second reactor L2 The second end of the three-phase input terminal is connected, the middle point of the fifth insulated gate bipolar transistor Q5 and the sixth insulated gate bipolar transistor Q6 connected in series is connected to the third end of the three-phase input terminal through the second fuse Fu2 and the third insulated gate bipolar transistor L3, the collector ends of the first insulated gate bipolar transistor Q1, the third insulated gate bipolar transistor Q3 and the fifth insulated gate bipolar transistor Q5 are connected to the DC bus DC+, the emitter ends of the second insulated gate bipolar transistor Q2, the fourth insulated gate bipolar transistor Q4 and the sixth insulated gate bipolar transistor Q6 are connected to the DC bus DC-, and the first capacitor C1 is connected The first resistor R1 and the fourth capacitor C4 are connected to the two ends of the series branch of the first insulated gate bipolar transistor Q1 and the second insulated gate bipolar transistor Q2, the second capacitor C2 is connected to the two ends of the series branch of the third insulated gate bipolar transistor Q3 and the fourth insulated gate bipolar transistor Q4, the third capacitor C3 is connected to the two ends of the series branch of the fifth insulated gate bipolar transistor Q5 and the sixth insulated gate bipolar transistor Q6, the first resistor R1 and the fourth capacitor C4 are connected to the DC bus DC+ at one end and the DC bus DC- at the other end respectively, the seventh insulated gate bipolar transistor Q7 and the eighth insulated gate bipolar transistor Q8 ... The ninth Q9 and the tenth insulated gate bipolar transistor Q10 are connected in series respectively, the middle point of the seventh insulated gate bipolar transistor Q7 and the eighth insulated gate bipolar transistor Q8 connected in series is connected to the first output terminal, the middle point of the ninth insulated gate bipolar transistor Q9 and the tenth insulated gate bipolar transistor Q10 connected in series is connected to the second output terminal, the fifth capacitor C5 is connected to both ends of the seventh insulated gate bipolar transistor Q7 and the eighth insulated gate bipolar transistor Q8 series branch, and the sixth capacitor C6 is connected to both ends of the ninth insulated gate bipolar transistor Q9 and the tenth insulated gate bipolar transistor Q10 series branch; One end of the battery cluster is connected to the DC bus DC+, and the other end is connected to the DC bus DC-.

[0016] The present application provides a high-voltage energy storage inverter system, which can achieve the following beneficial effects: Based on the inverter's own topology, the energy storage battery system of the battery cluster is combined to form a new partially controlled rectifier energy storage frequency conversion system, which can continue to provide power from the battery when the on-site power is cut off, ensuring that the load will not lose power during operation, allowing the load to continue to operate stably for a long time, and enhancing the reliability and safety of the entire power supply system. In addition, the star-connected topology structure of multiple-stage series connection is conducive to the storage and release of energy, and at the same time allows the load motor to perform flexible frequency conversion operation, meeting the demand for load power outages without stopping.

[0017] The topology provided by this system can realize the flexible flow of battery energy, can be used to support the stable operation of the load, and can also realize the intelligent charging and discharging operation of the battery, with high system integration and flexibility.

[0018] Moreover, this system changes some power units in the high-voltage inverter into controllable rectifier inverter units, while other units remain unchanged. This topology is simple and flexible, has good compatibility, small overall changes, low implementation difficulty, and outstanding cost advantages.

[0019] In addition, this system does not require power conversion control devices such as power storage converters (Power Conversion System, PCS). Signal control can be completely achieved by the frequency conversion main control unit of this system. There is no external signal intervention, all processing is internal, the control is simple, it can meet the needs of disturbance-free switching, and it is highly friendly to on-site operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art description are briefly introduced below. The drawings described here are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 A control schematic diagram of a high-voltage energy storage inverter system provided in an embodiment of the present application; Figure 2 A schematic diagram of a portion of the structure of a high-voltage energy storage inverter system provided in an embodiment of the present application; Figure 3 A topological structure diagram of the connection between the controllable rectifier inverter unit and the battery cluster provided in the embodiment of the present application; Figure 4 A four-quadrant topological structure diagram of a power unit provided in an embodiment of the present application; Figure 5 A two-quadrant topological structure diagram of a power unit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0022] Figure 1 A control schematic diagram of a high-voltage energy storage inverter system provided in an embodiment of the present application.

[0023] like Figure 1 As shown, the high-voltage inverter is connected to the battery cluster, and one end of the high-voltage inverter is connected to the power supply, and the other end is connected to the load M. When the power supply is normal, the high-voltage inverter transmits the current of the power supply to the load, and charges the battery cluster when the loop is connected. When the power supply is cut off, the battery cluster discharges, and its DC power is inverted into AC power through the high-voltage inverter, and then supplied to the load.

[0024] The power source may be a DC power source, an AC power source, a generator, etc., depending on the conditions at the power supply site.

[0025] The high-voltage energy storage inverter system can charge and discharge the connected battery cluster by adding rectification and inversion functions, so as to achieve continuous power supply to the load in the event of a power outage, ensuring that the load can run for a long time without interruption, thereby improving the safety and reliability of the entire power supply system.

[0026] Furthermore, an input contactor, a buffer contactor and a buffer resistor are provided at the input end of the high-voltage frequency converter. The buffer contactor is connected to the buffer resistor, one end of the input contactor is connected to the buffer contactor, and the other end is connected to the buffer resistor. The resistance value of the buffer resistor can be determined according to factors such as power supply and load in the power supply system.

[0027] By setting up a buffer contactor and a buffer resistor as a transitional connection between the high-voltage inverter and the power supply, the current can be limited, the voltage fluctuation of the power supply can be offset, and the voltage output of the inverter can be guaranteed to be stable, and the energy exchange process can be guaranteed to be more stable. Especially in high-power inverters, it plays a role in protecting capacitors and balancing voltages, which is conducive to improving the reliability and stability of the equipment.

[0028] Figure 2 A partial structural diagram of a high-voltage energy storage inverter system provided in an embodiment of the present application.

[0029] Generally speaking, the high-voltage inverter consists of three parts: the switch cabinet, the transformer cabinet and the power unit cabinet. The switch cabinet includes the input contactor, the buffer contactor and the buffer resistor; the transformer cabinet includes the phase-shifting transformer; the power unit cabinet includes the controllable rectifier inverter unit and the conventional power unit.

[0030] One end of the high-voltage inverter is connected to the power supply, and the other end is connected to the load; the buffer contactor is connected to the buffer resistor, one end of the input contactor is connected to the buffer contactor, and the other end is connected to the buffer resistor; the controlled rectifier inverter unit is connected to the power unit, usually one controlled rectifier inverter unit A1 can realize the inverter power supply when the power is off, and the number of other conventional power units An can be determined according to the specific situation; the phase-shifting transformer is respectively connected to the controlled rectifier inverter unit and the power unit to convert the input voltage into an independent three-phase voltage to supply power to the controlled rectifier inverter unit and the power unit; the controlled rectifier inverter unit is connected to the battery cluster, charges the battery cluster when the power is normally supplied, and inverts the DC power into AC power through the discharge of the battery cluster when the power is off, and supplies power to other power units through the phase-shifting transformer to ensure the normal operation of the load.

[0031] The high-voltage energy storage inverter system is equipped with a controllable rectifier inverter unit connected to the battery cluster. When the power is cut off, the electric energy stored in the battery cluster can be inverted into AC power, and the power flow is realized through a phase-shifting transformer. The power is then supplied to the load, and the variable frequency operation of the subsequent load motor is driven. This can achieve continuous power supply to the load in abnormal situations such as power outages, ensure long-term stable operation of the load, and improve the safety and reliability of the entire power supply system.

[0032] In one embodiment, a controllable rectifier inverter unit and at least one power unit form a transmission branch, and the high-voltage frequency converter may include multiple parallel transmission branches, each of which is connected to the load and is also connected to the phase-shifting transformer. The controllable rectifier inverter units in each transmission branch are connected to the battery cluster, and can receive current from the battery cluster when the power is off, and supply the load after inversion. When the frequency converter itself fails, the main circuit can be expanded according to demand to switch to normal operation at the industrial frequency. Through the multi-stage series connection of the controllable rectifier inverter unit and the power unit, and the parallel connection of multiple transmission branches, the current of the battery cluster can be transmitted to the load in a more stable form when the power is off, ensuring that the load is not affected by the power outage and can operate stably and sustainably.

[0033] For example, Figure 2As shown, the high-voltage inverter includes three transmission branches, of which A1, B1, and C1 are controllable rectifier inverter units, and An, Bn, and Cn are conventional power units. The controllable rectifier inverter unit and the power unit are respectively connected to the phase-shifting transformer, and the battery cluster is respectively connected to the controllable rectifier DC circuit of the three power units A1, B1, and C1 through an external battery contactor. The power device at the front end of the controllable rectifier inverter unit performs rectification and inversion control to realize the energy interaction of the battery.

[0034] When the power is off, the controlled rectifier inverter units A1, B1, and C1 invert the DC power of the connected battery clusters into AC power, and transmit it to the power units An, Bn, and Cn of the corresponding transmission branches through the phase-shifting transformer. The controlled rectifier inverter units and the power units jointly supply power to the load.

[0035] However, the topology of this system is not limited to connecting three units. It can also adopt multiple unit connections or single unit connections. As long as the energy exchange is controlled by the units, the battery energy can be converted to the transformer and then transmitted to other conventional power units to achieve stable operation of the load.

[0036] In addition, each transmission branch has an output contactor at its output end. By controlling the closing or opening of the output contactor, the connection relationship between each transmission branch and the load can be determined. For example, when a transmission branch fails, the corresponding output contactor can be disconnected to cut off the connection between the transmission branch and the load, and the load can be powered by other transmission branches.

[0037] In one embodiment, the phase-shifting transformer may be a multi-tap phase-shifting transformer to cope with changes in power supply voltage and maintain circuit voltage balance.

[0038] In one embodiment, the phase-shifting transformer can be connected in star connection, connecting the ends of the three windings of the three-phase power supply together to form a common point, and leading three end lines from the starting end. This connection method makes the starting current smaller, which is conducive to enhancing the safety and stability of the circuit and maintaining voltage balance. In addition, the star-connected topology structure after multi-stage series connection is conducive to the storage and release of energy, and at the same time allows the load motor to perform flexible frequency conversion operation, meeting the demand of non-stopping when the load is powered off.

[0039] In one embodiment, the controllable rectifier inverter unit and the power unit are respectively connected to the corresponding windings in the phase-shifting transformer. Among them, the winding connected to the controllable rectifier inverter unit is a special winding. The capacity of the special winding is determined based on the capacity of the battery cluster and the number of controllable rectifier inverter units, and the capacity of the special winding is negatively correlated with the number of controllable rectifier inverter units. That is, the more the number of controllable rectifier inverter units, the smaller the capacity selection of the special winding; the fewer the number of controllable rectifier inverter units, the larger the capacity selection of the special winding. It is determined that the capacity of the special winding must be able to achieve the capacity of dragging the load and meet the energy flow requirements of the battery cluster.

[0040] In one embodiment, the input side of the controllable rectifier inverter unit needs to be connected to the corresponding special winding in the phase-shifting transformer through a filter reactor, while the conventional power unit can be directly connected to the corresponding winding without connecting the filter reactor. The filter reactor is used to absorb harmonic current, improve the power factor, protect the motor facilities, ensure the safe operation of the power grid, and further optimize the performance of the power supply system.

[0041] In one embodiment, the controllable rectifier inverter unit can be set at any position of the transmission branch, and the inverter transmission of the battery cluster current can be realized. However, it is more preferable to set the controllable rectifier inverter unit at the sealing point of the high-voltage inverter. In the topological structure where the controllable rectifier inverter unit is set at the sealing point of the inverter, the connection relationship between the high-voltage inverter and the battery cluster can make the potential of the battery cluster more stable, which is conducive to the smooth transmission of the current and more convenient in control.

[0042] Figure 3 A topological structure diagram of the connection between the controllable rectifier inverter unit and the battery cluster provided in an embodiment of the present application.

[0043] like Figure 3 As shown, the battery cluster includes a plurality of battery packs Pack1 to PackN, a fuse Fu, and a battery contactor connected in sequence. When the battery contactor is closed, the battery cluster is connected to the circuit where the connected controllable rectifier inverter unit is located, which can realize the charging and discharging of the battery pack and the storage and release of energy. When the battery contactor is disconnected, the battery cluster is no longer connected to the controllable rectifier inverter unit. In this way, by connecting the controllable rectifier inverter unit through an external battery contactor, flexible energy exchange can be achieved.

[0044] Among them, the use of a battery cluster, which is composed of multiple battery packs, has more stable characteristics such as capacity, voltage and operating temperature range than a single battery unit, which is also beneficial to improving the stability of the power supply process and ensuring the smooth operation of the load.

[0045] In addition, the battery cluster also includes a battery management system (BMS), which can monitor the voltage, current, temperature and other parameters of the battery pack in real time, record the working data of the battery pack, dynamically balance the battery pack, and manage the charging and discharging process of the battery pack according to the working conditions. It can also perform fault diagnosis. When a battery pack fault is detected, the battery contactor is controlled to disconnect and the battery cluster and the controllable rectifier inverter unit are isolated to achieve safe operation and optimal utilization of the battery cluster, providing reliable support for the power supply process.

[0046] In general, the controllable rectifier inverter unit in this high-voltage variable frequency energy storage system is connected to each corresponding battery cluster. When the power supply voltage is normal, the on-site power supply is connected to the phase-shifting transformer through the input contactor and the buffer contactor. The special winding of the phase-shifting transformer is connected to the controllable rectifier inverter unit through the reactor, and the other windings are directly connected to the conventional power unit, finally realizing the energy flow and dragging the load to run. When the on-site power supply is lost, the energy in the battery cluster will be fed back to the special winding corresponding to the phase-shifting transformer through the controllable rectifier inverter unit, and then fed back to other windings, thereby driving all power units including the controllable rectifier inverter unit to drag the load to run. In addition, in each battery cluster, an additional contactor is configured, which can automatically disconnect the circuit connection when there is a problem on the energy storage battery side. Other main circuits can also be expanded in the topology to realize other conventional frequency conversion controls.

[0047] In one embodiment, Figure 3 As shown, in each phase battery cluster, N battery packs are connected according to the actual battery selection requirements, and are connected to the positive and negative buses of the controllable rectifier inverter unit through fuses and battery contactors. The three-phase input on site passes through the three-phase controlled rectifier part, the filter circuit, and is inverted to the unit output end through the power device. Each phase unit is cascaded to drive the on-site load. When the on-site high-voltage bus is normal, the three-phase input is connected to the battery after adjusting the corresponding voltage through the three-phase controlled rectifier part, and the battery can be charged and discharged. When the high-voltage bus on site is powered off, the energy of the battery will be inverted through the three-phase controlled rectifier part and converted into a controllable AC power supply again and returned to the other windings of the phase-shifting transformer, providing energy for all power units including the controllable rectifier inverter unit.

[0048] Specifically, the specific topological structure of the controllable rectifier inverter unit is as follows: The insulated gate bipolar transistors Q1 and Q2, Q3 and Q4, Q5 and Q6 are connected in series respectively, the middle point of the insulated gate bipolar transistors Q1 and Q2 in series is connected to the first end of the three-phase input terminal through the fuse Fu1 and the reactor L1, the middle point of the insulated gate bipolar transistors Q3 and Q4 in series is connected to the second end of the three-phase input terminal through the reactor L2, the middle point of the insulated gate bipolar transistors Q5 and Q6 in series is connected to the third end of the three-phase input terminal through the fuse Fu2 and the reactor L3, the collector ends of the insulated gate bipolar transistors Q1, Q3 and Q5 are connected to the DC bus DC+, the emitter ends of the insulated gate bipolar transistors Q2, Q4 and Q6 are connected to the DC bus DC-, and the capacitor C1 is connected to the insulated gate bipolar transistor Q1 and Q2 are connected in series at both ends of the branch connected in series with insulated gate bipolar transistors Q3 and Q4, capacitor C2 is connected in series at both ends of the branch connected in series with insulated gate bipolar transistors Q3 and Q4, capacitor C3 is connected in series at both ends of the branch connected in series with insulated gate bipolar transistors Q5 and Q6, resistor R1 and capacitor C4 are connected in series with the DC bus DC+ at one end and the DC bus DC- at the other end, insulated gate bipolar transistors Q7 and Q8, Q9 and Q10 are connected in series respectively, the middle point of the series connection of insulated gate bipolar transistors Q7 and Q8 is connected to the first output end, the middle point of the series connection of insulated gate bipolar transistors Q9 and Q10 is connected to the second output end, capacitor C5 is connected in series at both ends of the branch connected in series with insulated gate bipolar transistors Q7 and Q8, and capacitor C6 is connected in series at both ends of the branch connected in series with insulated gate bipolar transistors Q9 and Q10.

[0049] In addition, one end of the battery cluster is connected to the DC bus DC+, and the other end is connected to the DC bus DC-.

[0050] In one embodiment, the topology of a conventional power unit can be a two-quadrant structure or a four-quadrant structure. The specific topology used can be determined based on actual site needs. Both unit topologies can be compatible and meet various site needs, which can greatly improve the compatibility of the system.

[0051] In the two-quadrant structure, the unit topology includes an input uncontrolled rectifier module and an inverter power module to realize the rectification and inversion process of the grid energy, configure the corresponding filtering and voltage balancing circuits to realize the forward and reverse operation of the motor, and reduce the use cost of the energy storage inverter.

[0052] In the four-quadrant structure, the unit topology includes a controllable rectifier module and an inverter power module. The functions of the controllable rectifier module and the inverter module can be interchanged to achieve energy feedback on the load side. This can not only drive the motor forward and reverse, but also convert the kinetic energy of the motor during idling into electrical energy and feed it back to the power grid, thereby realizing energy collection.

[0053] Specifically, Figure 4 The four-quadrant topological structure diagram of the power unit provided in the embodiment of the present application, the specific topological structure is as follows: The insulated gate bipolar transistors Q11 and Q12, Q13 and Q14, Q15 and Q16 are connected in series respectively, the middle point of the insulated gate bipolar transistors Q11 and Q12 connected in series is connected to the first end of the three-phase input terminal through the fuse Fu3, the middle point of the insulated gate bipolar transistors Q13 and Q14 connected in series is connected to the second end of the three-phase input terminal, the middle point of the insulated gate bipolar transistors Q15 and Q16 connected in series is connected to the third end of the three-phase input terminal through the fuse Fu4, the collector ends of the insulated gate bipolar transistors Q11, Q13 and Q15 are connected to the DC bus DC+, the emitter ends of the insulated gate bipolar transistors Q12, Q14, Q16 are connected to the DC bus DC-, and the capacitor C7 is connected to the insulated gate bipolar transistors Q11 and Q12 series branch. The capacitor C8 is connected to both ends of the series branch of the insulated gate bipolar transistors Q13 and Q14, the capacitor C9 is connected to both ends of the series branch of the insulated gate bipolar transistors Q15 and Q16, the resistor R2 and the capacitor C10 are connected to the DC bus DC+ at one end and the DC bus DC- at the other end, the insulated gate bipolar transistors Q17 and Q18, Q19 and Q20 are connected in series respectively, the middle point of the series connection of the insulated gate bipolar transistors Q17 and Q18 is connected to the first output end, the middle point of the series connection of the insulated gate bipolar transistors Q19 and Q20 is connected to the second output end, the capacitor C11 is connected to both ends of the series branch of the insulated gate bipolar transistors Q17 and Q18, and the capacitor C12 is connected to both ends of the series branch of the insulated gate bipolar transistors Q19 and Q20.

[0054] Specifically, Figure 5 The two-quadrant topological structure diagram of the power unit provided in the embodiment of the present application, the specific topological structure is as follows: Diodes D1 and D2, D3 and D4, D5 and D6 are connected in series respectively, the middle point of the series connection of diodes D1 and D2 is connected to the first end of the three-phase input terminal through fuse Fu5, the middle point of the series connection of diodes D3 and D4 is connected to the second end of the three-phase input terminal, the middle point of the series connection of diodes D5 and D6 is connected to the third end of the three-phase input terminal through fuse Fu6, the cathode ends of diodes D1, D3, and D5 are connected to the DC bus DC+, the anode ends of diodes D2, D4, and D6 are connected to the DC bus DC-, and resistors R3 and D4 are connected to the DC bus DC+. One end of the capacitor C13 is connected to the DC bus DC+, and the other end is connected to the DC bus DC-, the insulated gate bipolar transistors Q21 and Q22, Q23 and Q24 are connected in series, the middle point of the series connection of the insulated gate bipolar transistors Q21 and Q22 is connected to the first output end, the middle point of the series connection of the insulated gate bipolar transistors Q23 and Q24 is connected to the second output end, the capacitor C14 is connected to the two ends of the series branch of the insulated gate bipolar transistors Q21 and Q22, and the capacitor C15 is connected to the two ends of the series branch of the insulated gate bipolar transistors Q23 and Q24.

[0055] It should be noted that the topology proposed by this system does not limit the type of battery, the voltage level of the high-voltage inverter, or the type of conventional power unit mentioned, as long as the functions described by this system can be achieved.

[0056] The various embodiments in the present application are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0057] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0058] The above is only the embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A high voltage energy storage inverter system, characterized in that: Including high-voltage inverter and battery cluster; The high-voltage frequency converter includes a phase-shifting transformer, a connected controllable rectifier inverter unit and a power unit; The phase-shifting transformer is connected to the controllable rectifier inverter unit and the power unit respectively; The controllable rectifying and inverting unit is also connected to the battery cluster; One end of the high-voltage inverter is connected to a power source, and the other end is connected to a load; when the power source is supplying power normally, the high-voltage inverter transmits the current of the power source to the load and charges the battery cluster; when the power source is cut off, the high-voltage inverter inverts the direct current of the battery cluster into alternating current through the controllable rectifier inverter unit, transmits it to the phase-shifting transformer, and supplies the load through the controllable rectifier inverter unit and the power unit.

2. The high-voltage energy storage inverter system according to claim 1, characterized in that: The high-voltage frequency converter comprises a plurality of parallel transmission branches, each of the transmission branches comprises the controllable rectifier inverter unit and at least one of the power units, and each of the transmission branches is connected to the load.

3. The high-voltage energy storage inverter system according to claim 2, characterized in that: The capacity of the winding in the phase-shifting transformer connected to the controllable rectifier inverter unit is determined based on the capacity of the battery cluster and the number of the controllable rectifier inverter units, and is negatively correlated with the number of the controllable rectifier inverter units.

4. The high-voltage energy storage inverter system according to claim 1, characterized in that: The controllable rectifying and inverting unit is arranged at the star-sealing point of the high-voltage frequency converter.

5. The high-voltage energy storage inverter system according to claim 1, characterized in that: The controllable rectifying and inverting unit is connected to the corresponding winding in the phase-shifting transformer through a filter reactor.

6. The high-voltage energy storage inverter system according to claim 1, characterized in that: The battery cluster includes a plurality of battery packs, fuses, and battery contactors connected in sequence; When the battery contactor is closed, the battery cluster is connected to the circuit where the connected controllable rectifier inverter unit is located.

7. The high-voltage energy storage inverter system according to claim 6, characterized in that: The battery cluster further includes a battery management system, which controls the battery contactor to be disconnected when a fault of the battery pack is detected.

8. The high-voltage energy storage inverter system according to claim 1, characterized in that: The frequency converter also includes an input contactor, a buffer contactor, and a buffer resistor; The buffer contactor is connected to the buffer resistor, one end of the input contactor is connected to the buffer contactor, and the other end is connected to the buffer resistor.

9. The high-voltage energy storage inverter system according to claim 1, characterized in that: The topological structure of the power unit is a two-quadrant or four-quadrant structure.

10. The high-voltage energy storage inverter system according to claim 6, characterized in that: The topological structure of the connection between the controllable rectifier inverter unit and the battery cluster includes: The first insulated gate bipolar transistor Q1 and the second insulated gate bipolar transistor Q2, the third insulated gate bipolar transistor Q3 and the fourth insulated gate bipolar transistor Q4, the fifth insulated gate bipolar transistor Q5 and the sixth insulated gate bipolar transistor Q6 are connected in series respectively, the middle point of the series connection of the first insulated gate bipolar transistor Q1 and the second insulated gate bipolar transistor Q2 is connected to the first end of the three-phase input terminal through the first fuse Fu1 and the first reactor L1, the middle point of the series connection of the third insulated gate bipolar transistor Q3 and the fourth insulated gate bipolar transistor Q4 is connected to the first end of the three-phase input terminal through the second reactor L2 The second end of the three-phase input terminal is connected, the middle point of the fifth insulated gate bipolar transistor Q5 and the sixth insulated gate bipolar transistor Q6 connected in series is connected to the third end of the three-phase input terminal through the second fuse Fu2 and the third insulated gate bipolar transistor L3, the collector ends of the first insulated gate bipolar transistor Q1, the third insulated gate bipolar transistor Q3 and the fifth insulated gate bipolar transistor Q5 are connected to the DC bus DC+, the emitter ends of the second insulated gate bipolar transistor Q2, the fourth insulated gate bipolar transistor Q4 and the sixth insulated gate bipolar transistor Q6 are connected to the DC bus DC-, and the first capacitor C1 is connected The first resistor R1 and the fourth capacitor C4 are connected to the two ends of the series branch of the first insulated gate bipolar transistor Q1 and the second insulated gate bipolar transistor Q2, the second capacitor C2 is connected to the two ends of the series branch of the third insulated gate bipolar transistor Q3 and the fourth insulated gate bipolar transistor Q4, the third capacitor C3 is connected to the two ends of the series branch of the fifth insulated gate bipolar transistor Q5 and the sixth insulated gate bipolar transistor Q6, the first resistor R1 and the fourth capacitor C4 are connected to the DC bus DC+ at one end and the DC bus DC- at the other end respectively, the seventh insulated gate bipolar transistor Q7 and the eighth insulated gate bipolar transistor Q8 ... The ninth Q9 and the tenth insulated gate bipolar transistor Q10 are connected in series respectively, the middle point of the seventh insulated gate bipolar transistor Q7 and the eighth insulated gate bipolar transistor Q8 connected in series is connected to the first output terminal, the middle point of the ninth insulated gate bipolar transistor Q9 and the tenth insulated gate bipolar transistor Q10 connected in series is connected to the second output terminal, the fifth capacitor C5 is connected to both ends of the seventh insulated gate bipolar transistor Q7 and the eighth insulated gate bipolar transistor Q8 series branch, and the sixth capacitor C6 is connected to both ends of the ninth insulated gate bipolar transistor Q9 and the tenth insulated gate bipolar transistor Q10 series branch; One end of the battery cluster is connected to the DC bus DC+, and the other end is connected to the DC bus DC-.

Images