Vrf energy storage system

Abstract

The application provides a VRF energy storage system, comprising a VRF main control board and a battery unit. The VRF main control board comprises a power supply for supplying power for the VRF energy storage system, a rectifier circuit connected with the power supply, an inverter circuit with an input end connected with the rectifier circuit and an output end configured to be connected with a load, and a first wireless module arranged between the rectifier circuit and the inverter circuit and connected with a direct current voltage output end of the VRF main control board. The battery unit comprises a second wireless module capable of performing wireless bidirectional transmission of electric energy with the first wireless module, and a battery connected with the second wireless module. In the above manner, the first wireless module and the second wireless module are arranged between the VRF main control board and the battery unit to perform wireless bidirectional transmission of electric energy, so that a large number of modifications of wiring of equipment are avoided, and the VRF main control board and the battery unit are easy to modify and apply on the basis of existing hardware, and the assembly positions and distances of the VRF main control board and the battery unit are more flexible.

Description

Technical Field

[0001] This application relates to the field of energy storage system technology, and specifically to a VRF (Variable Refrigerant Flow) energy storage system. Background Technology

[0002] In air conditioning systems, traditional energy storage solutions use a combination of DC-DC (Direct Current) converters and battery packs. The DC-DC converter and battery pack are connected to the driver on the VRF main control board via cables to store energy in the air conditioning system. However, this approach requires significant modifications to the air conditioning system's wiring, making it inconvenient for production implementation. Summary of the Invention

[0003] To address the above issues, this application provides a VRF energy storage system that can at least solve some of the problems in the prior art.

[0004] This application provides a VRF energy storage system, including a VRF main control board and a battery unit. The VRF main control board includes: a power supply for powering the VRF energy storage system; a rectifier circuit connected to the power supply and capable of converting AC power to DC power; an inverter circuit with its input connected to the rectifier circuit and its output configured for connecting to a load, capable of converting DC power to AC power required by the load; and a first wireless module disposed between the rectifier circuit and the inverter circuit, connected to the DC voltage output terminal of the VRF main control board. The battery unit includes: a second wireless module capable of bidirectional wireless power transmission with the first wireless module; and a battery connected to the second wireless module.

[0005] By employing the above method, a first wireless module is installed at the DC voltage output terminal of the VRF main control board, and a second wireless module is installed at the battery of the battery unit. Power is transmitted bidirectionally wirelessly through the first and second wireless modules. Because a wireless method is used, no major modifications to existing hardware are required, and no additional wiring is needed between the VRF main control board and the battery unit, making it easy to modify and apply based on existing hardware. In addition, the wireless power transmission method is not only more efficient, but also achieves electrical isolation between the VRF main control board side and the battery unit side, improving circuit safety. In particular, if a circuit failure occurs on one side, it is easier for staff to perform safe and convenient maintenance. The VRF main control board and the battery unit do not need to be connected by cables, making their assembly position and distance more flexible.

[0006] Optionally, the first wireless module includes: a first switching circuit, with a first terminal connected to a DC voltage output terminal; and a first resonant circuit, with a first terminal connected to a second terminal of the first switching circuit.

[0007] In this manner, a first switching circuit and a first resonant circuit are sequentially configured at the DC voltage output terminal of the VRF main control board. When the VRF energy storage system is in Powering Mode, the voltage output from the DC voltage output terminal serves as the charging voltage for the battery cells. Power is supplied to the battery cells through the first switching circuit and the first resonant circuit (i.e., the first wireless module) connected to the DC voltage output terminal. When the VRF energy storage system is in Generating Mode, the energy from the battery cells is fed back to the DC voltage output terminal through the first wireless module connected to the second wireless module, thus realizing bidirectional wireless power transmission of the VRF energy storage system.

[0008] Optionally, the second wireless module includes: a second resonant circuit, the first end of which is wirelessly connected to the second end of the first resonant circuit; and a second switching circuit, the first end of which is connected to the second end of the second resonant circuit, and the second end of the second switching circuit is connected to the battery.

[0009] By employing the above method, a second switching circuit and a second resonant circuit are sequentially arranged on the battery side of the battery unit. When the VRF energy storage system is in power output mode, the DC voltage output terminal uses the voltage output by the first wireless module as the battery charging voltage, i.e., power is supplied to the battery through the second wireless module connected to the first wireless module. When the VRF energy storage system is in energy feedback mode, the battery's energy is fed back to the DC voltage output terminal, and the battery side supplies power to the DC voltage output terminal through the second switching circuit and the second resonant circuit. Through the cooperation of the second resonant circuit and the first resonant circuit, bidirectional wireless power transmission of the VRF energy storage system is achieved.

[0010] Optionally, the first switching circuit includes a first H-bridge IGBT composed of a first IGBT (Insulated Gate Bipolar Transistor), a second IGBT, a third IGBT, and a fourth IGBT.

[0011] In this way, the first wireless module uses four IGBT switching elements to form a first H-bridge IGBT. By frequently switching the combination of these four switching elements on and off, the DC voltage output from the DC voltage output terminal is converted into a high-frequency AC voltage. Simultaneously, the low conduction losses of the IGBT switching elements are beneficial for improving the operating efficiency of the VRF energy storage system in power output mode.

[0012] Optionally, the first resonant circuit includes a first inductor, a first coil, and a first capacitor arranged in sequence. The first end of the first inductor is connected to the first switching circuit, the second end of the first inductor is connected to the first end of the first coil, the second end of the first coil is connected to the first end of the first capacitor, and the second end of the first capacitor is connected to the first switching circuit.

[0013] In the above manner, in power output mode, the first resonant circuit and the first coil of the first wireless module perform energy transmission and voltage conversion on the AC voltage output after high-frequency switching of the first switching circuit, and after rectification, transmit it to the second wireless module to power the battery.

[0014] Optionally, the second switching circuit includes a second H-bridge IGBT composed of a fifth IGBT, a sixth IGBT, a seventh IGBT, and an eighth IGBT.

[0015] In this way, the second wireless module uses four IGBT switching elements to form a second H-bridge IGBT. By frequently switching the combination of these four switching elements on and off, the DC voltage output from the battery side is converted into a high-frequency AC voltage. Simultaneously, the low conduction losses of the IGBT switching elements are beneficial for improving the operating efficiency of the VRF energy storage system in energy feedback mode.

[0016] Optionally, the second resonant circuit includes a second inductor, a second coil, and a second capacitor arranged sequentially. The first end of the second inductor is connected to the second switching circuit, the second end of the second inductor is connected to the first end of the second coil, the second end of the second coil is connected to the first end of the second capacitor, and the second end of the second capacitor is connected to the second switching circuit. The frequency of the second coil is the same as the frequency of the first coil, or both the second coil and the first coil vibrate within a preset frequency range, enabling bidirectional wireless power transmission.

[0017] In the above manner, under the energy feedback mode, the second resonant circuit and the second coil of the second wireless module transmit energy and convert the AC voltage output by the high-frequency switching of the second switching circuit, and after rectification, transmit it to the DC voltage output terminal of the first wireless module to power the VRF main control board.

[0018] Optionally, the rectifier circuit is a rectifier bridge.

[0019] By using the above methods, AC power is converted into DC power using a rectifier bridge, reducing energy loss, improving the overall efficiency of the system, and simplifying the circuit structure, making the circuit design of the VRF energy storage system simpler and more efficient.

[0020] Optionally, the inverter circuit includes a third inductor, a switching transistor, a diode, a third capacitor, and an inverter unit. The first end of the third inductor is connected to the first output terminal of the rectifier circuit. The switching transistor is connected between the second end of the third inductor and the second output terminal of the rectifier circuit. The anode of the diode is connected to the second end of the third inductor. The cathode of the diode is connected to the first end of the third capacitor and the first input terminal of the inverter unit. The second end of the third capacitor is connected to the second output terminal of the rectifier circuit and the second input terminal of the inverter unit. The output terminal of the inverter unit is configured to connect a load.

[0021] In this way, the inverter circuit can convert the DC voltage output by the rectifier circuit into AC voltage and then transmit it to the load, thereby supplying power to the load. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the VRF energy storage system in the embodiments of this application.

[0023] Figure 2 This is a schematic diagram of the circuit architecture of the VRF main control board side in the VRF energy storage system according to the embodiments of this application.

[0024] Figure 3 This is a circuit diagram of the battery cell side in the VRF energy storage system according to the embodiments of this application.

[0025] Figure label:

[0026] 100. VRF energy storage system;

[0027] 1. VRF main control board;

[0028] 11. Power supply;

[0029] 12. Rectifier circuit;

[0030] 13. Inverter circuit; 131. Switching transistor; 132. Diode; 133. Inverter unit;

[0031] 14. First wireless module; 141. First switching circuit; 1411. First branch; 1412. Second branch; 142. First resonant circuit; 1421. First coil;

[0032] 15. Load;

[0033] 2. Battery unit;

[0034] 21. Battery;

[0035] 22. Second wireless module; 221. Second switching circuit; 2211. Third branch; 2212. Fourth branch; 222. Second resonant circuit; 2221. Second coil. Detailed Description of the Embodiments

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present application.

[0037] <VRF energy storage system 100>

[0038] Figure 1 is a schematic diagram of the VRF energy storage system 100 in the embodiments of the present application. Figure 2 is a schematic circuit diagram on the VRF main control board 1 side in the VRF energy storage system 100 in the embodiments of the present application.

[0039] Figure 3 is a schematic circuit diagram on the battery unit 2 side in the VRF energy storage system 100 in the embodiments of the present application.

[0040] in conjunction with Figure 1 , and with reference to Figure 2 and Figure 3 , the present application provides a VRF energy storage system 100, which includes a VRF main control board 1 and a battery unit 2. The VRF main control board 1 includes a power supply 11, a rectifier circuit 12, an inverter circuit 13, and a first wireless module 14. The power supply 11 can supply power to the entire VRF energy storage system 100. The rectifier circuit 12 is connected to the power supply 11, and can convert alternating current output by the power supply 11 into direct current. The input end of the inverter circuit 13 is connected to the output end of the rectifier circuit 12, and the output end of the inverter circuit 13 is configured to be connected to a load 15, and can convert the direct current output by the rectifier circuit 12 into alternating current required by the load 15. The first wireless module 14 is disposed between the rectifier circuit 12 and the inverter circuit 13, and is connected to the DC voltage output end of the VRF main control board 1. The battery unit 2 includes a second wireless module 22 and a battery 21. The second wireless module 22 can perform bidirectional wireless power transmission with the first wireless module 14. The battery 21 is connected to the second wireless module 22, and can receive electric energy output by the second wireless module 22 or output electric energy to the second wireless module 22.

[0041] When the VRF energy storage system 100 is in the power output mode, part of the direct current output by the rectifier circuit 12 passes through the inverter circuit 13 and is converted into alternating current to supply power to the load 15, and the other part is output to the first wireless module 14 through the direct current voltage output end. The first wireless module 14 on the VRF main control board 1 transmits electric energy to the second wireless module 22 on the battery unit 2 in a wireless transmission manner, and the second wireless module 22 transmits the electric energy to the battery 21 to charge the battery 21. When the VRF energy storage system 100 is in the energy feedback mode, the direct current of the battery 21 is transmitted to the first wireless module 14 of the VRF main control board 1 through the second wireless module 22 on the battery unit 2, and the first wireless module 14 transmits the electric energy to the direct current voltage output end, so that the inverter circuit 13 converts the direct current fed back by the battery 21 into alternating current to supply power to the load 15.

[0042] It should be noted that the VRF energy storage system 100 in the embodiments of the present application can be applied to an air conditioning system, and the load 15 may be an air conditioning load 15.

[0043] Through the above manner, the first wireless module 14 is arranged at the direct current voltage output end of the VRF main control board 1, and the second wireless module 22 is arranged at the battery 21 of the battery unit 2. The first wireless module 14 and the second wireless module 22 are used for bidirectionally transmitting electric energy in a wireless manner, which avoids a large amount of modification to the wiring of the equipment, is easy to be directly used in existing production, makes the equipment not limited by distance and position, and makes electric energy transmission more flexible. At the same time, the arrangement of the first wireless module 14 and the second wireless module 22 realizes electrical isolation between the VRF main control board 1 side and the battery unit 2 side, and improves the safety of the circuit.

[0044] The components of the VRF energy storage system 100 are described below.

[0045] <VRF main control board 1 — Power supply 11>

[0046] As shown in Figure 1 and Figure 2 , the power supply 11 supplies power to the entire VRF energy storage system 100. The power supply 11 may be mains electricity or industrial electricity, etc., and can output alternating current.

[0047] <VRF main control board 1 — Rectifier circuit 12>

[0048] As shown in Figure 1 and 2 , the rectifier circuit 12 is a rectifier bridge, which is connected to the power supply 11 and can convert the alternating current output by the power supply 11 into direct current.

[0049] Through the above manner, the rectifier bridge is used to convert alternating current into direct current, which reduces energy loss, improves the overall efficiency of the system, and simplifies the circuit structure on the side of the VRF main control board 1, making the circuit design of the VRF energy storage system 100 more concise and efficient.

[0050] In some embodiments, the rectifier circuit 12 may also be implemented by a voltage doubler rectifier circuit 12, a full-wave rectifier circuit 12, a bridge rectifier circuit 12, etc., and the present application does not limit the type of the rectifier circuit 12.

[0051] <VRF main control board 1 —— inverter circuit 13>

[0052] As shown in Figure 1 and Figure 2 , the inverter circuit 13 includes a third inductor Lr3, a switching tube 131, a diode 132, a third capacitor Cr3 and an inverter unit 133 arranged in sequence. The first end of the third inductor Lr3 is connected to the first output end of the rectifier circuit 12, the switching tube 131 is connected between the second end of the third inductor Lr3 and the second output end of the rectifier circuit 12, the anode of the diode 132 is connected to the second end of the third inductor Lr3, the cathode of the diode 132 is connected to the first end of the third capacitor Cr3 and the first input end of the inverter unit 133, the second end of the third capacitor Cr3 is connected to the second output end of the rectifier circuit 12 and the second input end of the inverter unit 133, and the output end of the inverter unit 133 is configured to be connected to the load 15.

[0053] The inverter unit 133 in the inverter circuit 13 may be an inverter, which can receive the direct current output from the rectifier circuit 12 from the input end, convert it into alternating current, and output the alternating current to the load 15 from the output end, so as to supply power to the load 15. The inverter has two input ends, and the output end can output three-phase alternating current, that is, the inverter is two-in three-out. In some embodiments, the inverter can also be set as two-in one-out or multi-in multi-out, etc. The present application does not limit the setting mode of the inverter unit 133, as long as the above voltage transmission can be realized.

[0054] Through the above manner, the inverter circuit 13 can convert the direct current voltage output by the rectifier circuit 12 into alternating current voltage and then transmit it to the load 15, so as to supply power to the load 15.

[0055] <VRF main control board 1 —— first wireless module 14>

[0056] As shown in Figure 1 and Figure 2As shown, the first wireless module 14 includes a first switching circuit and a first resonant circuit 142. A first terminal of the first switching circuit is connected to a DC voltage output terminal, and a second terminal of the first switching circuit is connected to a first terminal of the first resonant circuit 142. The second terminal of the first resonant circuit 142 is wirelessly connected to a second resonant circuit 222 of the second wireless module 22. The DC voltage output terminal includes DC+ (positive) and DC- (negative).

[0057] In this manner, a first switching circuit and a first resonant circuit 142 are sequentially configured at the DC voltage output terminal of the VRF main control board 1. When the VRF energy storage system 100 is in power output mode, the voltage output from the DC voltage output terminal serves as the charging voltage for the battery unit 2. Power is supplied to the battery unit 2 through the first switching circuit and the first resonant circuit 142 (i.e., the first wireless module 14) connected to the DC voltage output terminal. When the VRF energy storage system 100 is in energy feedback mode, the energy from the battery unit 2 is fed back to the DC voltage output terminal through the first wireless module 14 connected to the second wireless module 22, thus realizing bidirectional wireless power transmission of the VRF energy storage system 100.

[0058] refer to Figure 2 The first switching circuit includes a first IGBT (such as...) Figure 2 Si1 in the middle), the second IGBT (such as Si1), and the second IGBT (such as Si1). Figure 2 Si2 in the middle), the third IGBT (such as Si2), and the third IGBT (such as Si2). Figure 2 Si3) and the fourth IGBT (such as Figure 2 The first H-bridge IGBT is composed of Si1 and Si2 (Si4). This first H-bridge IGBT is a DC motor control circuit with an H-shaped circuit. It includes two parallel branches: Si1 and Si3 are located in the first branch 1411, with Si1 connected to DC+ and Si3 connected to DC-; Si4 and Si2 are located in the second branch 1412. Both the first and second branches are connected to the first resonant circuit 142. The two IGBTs on the same branch cannot conduct simultaneously; that is, the first switching circuit can include two conduction modes: Si1 and Si2 conduct simultaneously, while Si3 and Si4 are off / turned off; or Si3 and Si4 conduct simultaneously, while Si1 and Si2 are off / turned off.

[0059] Continue to refer to Figure 2The first resonant circuit 142 includes a first inductor Lr1, a first coil 1421, and a first capacitor Cr1 arranged sequentially. The first end of the first inductor Lr1 is connected to the first branch 1411 of the first switching circuit 141, the second end of the first inductor Lr1 is connected to the first end of the first coil 1421, the second end of the first coil 1421 is connected to the first end of the first capacitor Cr1, and the second end of the first capacitor Cr1 is connected to the second branch 1412 of the first switching circuit 141. The frequency of the first coil 1421 is the same as the frequency of the second coil 2221 of the second wireless module 22, or both the first coil 1421 and the second coil 2221 vibrate within a preset frequency range, enabling bidirectional wireless power transmission.

[0060] refer to Figure 1 and Figure 2 When the VRF energy storage system 100 is in power output mode, current flows from the DC voltage output terminal of the VRF main control board 1 through the first wireless module 14 and the second wireless module 22 to the battery 21. Specifically, the current flow between the first wireless module 14 and the second wireless module 22 is as follows:

[0061] When Si1 and Si2 are turned on, the current flows from DC+ of VRF main control board 1 through Si1, Lr1, first coil 1421, second wireless module 22 (i.e., flows sequentially through the second coil 2221, Cr2, Lr2 of the second wireless module 22), Cr1, Si2 to DC-.

[0062] When Si3 and Si4 are turned on, the current flows from DC+ of VRF main control board 1 through Si4, Cr1, first coil 1421, second wireless module 22 (i.e., flows sequentially through the second coil 2221, Lr2, Cr2 of the second wireless module 22), Lr1, Si3 to DC-.

[0063] By alternately switching on Si1 and Si2, or Si3 and Si4, the DC voltage is converted into a high-frequency AC voltage. Meanwhile, the low conduction loss of the IGBT switching element helps improve the operating efficiency of the VRF energy storage system 100 in power output mode.

[0064] It should be noted that in power output mode, the second switching circuit So1-So4 of the second wireless module 22: the switching elements So1-So4 are usually in the off state, so there is no obvious current flowing through them.

[0065] In the above manner, in the power output mode, the first resonant circuit 142 and the first coil 1421 of the first wireless module 14 perform energy transmission and voltage conversion on the AC voltage output after the high-frequency switching of the first switching circuit, and after rectification, transmit it to the second wireless module 22 to power the battery 21.

[0066] <Battery Unit 2 - Second Wireless Module 22>

[0067] like Figure 2 and Figure 3 As shown, the second wireless module 22 includes a second switching circuit and a second resonant circuit 222. The first end of the second resonant circuit 222 is wirelessly connected to the second end of the first resonant circuit 142, the second end of the second resonant circuit 222 is connected to the first end of the second switching circuit, and the second end of the second switching circuit is connected to the battery 21.

[0068] In the above manner, a second switching circuit and a second resonant circuit 222 are sequentially arranged on the battery 21 side of battery unit 2. When the VRF energy storage system 100 (e.g.) Figure 1 When the VRF energy storage system 100 is in power output mode, the voltage output from the DC voltage output terminal via the first wireless module 14 is used as the charging voltage for the battery 21, i.e., power is supplied to the battery 21 through the second wireless module connected to the first wireless module 14. When the VRF energy storage system 100 is in energy feedback mode, the energy of the battery 21 is fed back to the DC voltage output terminal, and power is supplied to the DC voltage output terminal from the battery 21 side through the second switching circuit and the second resonant circuit 222. Through the cooperation of the second resonant circuit 222 and the first resonant circuit 142, bidirectional wireless power transmission of the VRF energy storage system 100 is realized.

[0069] refer to Figure 3 The second switching circuit includes a fifth IGBT (such as...) Figure 3 So1 in the middle), the sixth IGBT (such as Figure 3 So2 in the middle), the seventh IGBT (such as Figure 3 So3) and the eighth IGBT (such as Figure 2 The second H-bridge IGBT consists of So4 and So3. This second H-bridge IGBT is a DC motor control circuit with an H-shaped circuit. It includes two parallel branches: So1 and So3 are located in the third branch 2211, with So1 connected to the positive terminal of battery 21 and So3 connected to the negative terminal; So4 and So2 are located in the fourth branch 2212. Both the third and fourth branches 2211 and 2212 are connected to the second resonant circuit 222. The two IGBTs on the same branch are configured to conduct alternately. Specifically, the second switching circuit can include two conduction modes: So1 and So2 are simultaneously on, while So3 and So4 are off / turned off; or, So3 and So4 are simultaneously on, while So1 and So2 are off / turned off.

[0070] Alternatively, the first to eighth IGBTs can be replaced with other types of switching transistors, such as MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors).

[0071] Continue to refer to Figure 3 The second resonant circuit 222 includes a second inductor Lr2, a second coil 2221, and a second capacitor Cr2 arranged sequentially. The first end of the second inductor Lr2 is connected to the third branch 2211 of the second switching circuit 221. The second end of the second inductor Lr2 is connected to the first end of the second coil 2221. The second end of the second coil 2221 is connected to the first end of the second capacitor Cr2. The second end of the second capacitor Cr2 is connected to the fourth branch 2212 of the second switching circuit 221. The frequency of the second coil 2221 is the same as the frequency of the first coil 1421, or both the second coil 2221 and the first coil 1421 vibrate within a preset frequency range, enabling bidirectional wireless power transmission.

[0072] refer to Figure 1 , Figure 2 and Figure 3 When the VRF energy storage system 100 is in energy feedback mode, current flows from battery 21 through second wireless module 22 and first wireless module 14 to the DC voltage output terminal of VRF main control board 1. Specifically, the current flow between second wireless module 22 and first wireless module 14 is as follows:

[0073] When So1 and So2 are turned on, the current flows from the positive terminal of the battery 21 of the battery cell 2 through So1, Lr2, the second coil 2221, the first wireless module 14 (that is, the current flows through the first coil 1421, Cr1, Lr1, Cr2, and So2 in sequence to the negative terminal of the battery 21.

[0074] When So3 and So4 are turned on, the current flows from the positive terminal of battery 21 of battery cell 2 through So4, Cr2, the second coil 2221, the first wireless module 14 (i.e., the current flows sequentially through the first coil 1421, Lr1, Cr1, Lr2, and So3) to the negative terminal of battery 21.

[0075] By alternately turning on So1 and So2, or alternately turning on So3 and So4, the DC voltage output by battery 21 is converted into a high-frequency AC voltage.

[0076] It should be noted that in the energy feedback mode, the first switching circuit Si1-Si4 of the first wireless module 14: the switching elements Si1-Si4 are usually in the off state, so there is no obvious current flowing through them.

[0077] In the energy feedback mode, the second resonant circuit 222 and the second coil 2221 of the second wireless module 22 transmit energy and convert the AC voltage output from the high-frequency switch of the second switching circuit. After rectification, the voltage is transmitted to the DC voltage output side of the first wireless module 14 for power supply. By using the first resonant circuit 142 and the second resonant circuit 222, IGBT switching losses are reduced. Due to the low energy loss of the first wireless module 14 and the second wireless module 22, the overall performance and efficiency of the VRF energy storage system 100 are improved.

[0078] The first coil 1421 of the first resonant circuit 142 and the second coil 2221 of the second resonant circuit 222 can be regarded as transformers. The output voltage is controlled by frequency conversion, and the voltage adjustment range is wide. That is, efficient power conversion is achieved through resonant characteristics, and the stability of voltage and current is maintained.

[0079] <Battery Unit 2 - Battery 21>

[0080] like Figure 3 As shown, the positive and negative terminals of battery 21 are connected to the two ends of the third branch 2211 of the second switching circuit, respectively. When maintenance of battery 21 is required, the second wireless module 22 can be added or replaced to achieve more convenient and faster equipment maintenance.

[0081] The working process of the VRF energy storage system 100 in the embodiments of this application will be described in detail below.

[0082] When the VRF energy storage system 100 is in power output mode, the AC power output by the power supply 11 of the VRF main control board 1 is converted into DC power by the rectifier circuit 12, and the electrical energy is transmitted to the battery cell 2 through the DC voltage output terminal and the first wireless module 14.

[0083] The first switching circuit of the first wireless module 14, i.e., the first H-bridge IGBT, is in the working state, while the second switching circuit of the second wireless module 22, i.e., the second H-bridge IGBT, is in the off state. The DC power from the rectifier circuit 12 is output through the DC voltage output terminal of the VRF main control board 1. This DC power is then used to generate high-frequency AC power through the four switching elements Si1-Si4 of the first H-bridge IGBT of the first wireless module 14, and is transmitted to the first resonant circuit 142 of the first wireless module 14. Electrical energy is converted from the first coil 1421 of the first resonant circuit 142 through magnetic field coupling and transmitted to the second coil 2221 of the second wireless module 22. After rectification, the DC power is transmitted to the battery 21 to charge it.

[0084] When the VRF energy storage system 100 is in energy feedback mode, electrical energy is transmitted through the battery 21 on the battery cell 2 side to the DC voltage output terminal of the VRF main control board 1 via the second wireless module 22.

[0085] The second switching circuit of the second wireless module 22, i.e., the second H-bridge IGBT, is in the working state, while the first switching circuit of the first wireless module 14, i.e., the first H-bridge IGBT, is in the off state. The energy from the battery 21 terminal is used to generate high-frequency alternating current through the four switching elements So1-So4 of the second H-bridge IGBT of the second wireless module 22, and then transmitted to the second resonant circuit 222 of the second wireless module 22. The electrical energy is converted from the second coil 2221 of the second resonant circuit 222 through magnetic field coupling and transmitted to the first coil 1421 of the first wireless module 14. After rectification, the DC voltage is transmitted to the DC voltage output terminal of the VRF main control board 1, so that the inverter circuit 13 connected to the DC voltage output terminal can supply power to the load 15 through the output terminal.

[0086] The technical solution of this application has now been described in conjunction with the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to the specific embodiments described above. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions resulting from these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A VRF energy storage system, characterized in that, include: VRF main control board, including: power supply, for supplying power to the VRF energy storage system; A rectifier circuit, connected to the power supply, is capable of converting the alternating current (AC) of the power supply into direct current (DC). An inverter circuit, with its input connected to the rectifier circuit and its output configured for connecting to a load, is capable of converting the direct current (DC) into alternating current (AC) required by the load; and The first wireless module is disposed between the rectifier circuit and the inverter circuit and is connected to the DC voltage output terminal of the VRF main control board; The battery cell includes: The second wireless module is capable of bidirectional power transmission with the first wireless module wirelessly. The battery is connected to the second wireless module.

2. The VRF energy storage system according to claim 1, characterized in that, The first wireless module includes: The first switching circuit has its first terminal connected to the DC voltage output terminal. The first resonant circuit has its first terminal connected to the second terminal of the first switching circuit.

3. The VRF energy storage system according to claim 2, characterized in that, The second wireless module includes: The second resonant circuit has its first end wirelessly connected to the second end of the first resonant circuit. The second switching circuit has its first terminal connected to the second terminal of the second resonant circuit, and its second terminal connected to the battery.

4. The VRF energy storage system according to claim 3, characterized in that, The first switching circuit includes a first H-bridge IGBT composed of a first IGBT, a second IGBT, a third IGBT, and a fourth IGBT.

5. The VRF energy storage system according to claim 4, characterized in that, The first resonant circuit includes a first inductor, a first coil, and a first capacitor arranged in sequence. The first end of the first inductor is connected to the first switching circuit, the second end of the first inductor is connected to the first end of the first coil, the second end of the first coil is connected to the first end of the first capacitor, and the second end of the first capacitor is connected to the first switching circuit.

6. The VRF energy storage system according to claim 5, characterized in that, The second switching circuit includes a second H-bridge IGBT composed of a fifth IGBT, a sixth IGBT, a seventh IGBT, and an eighth IGBT.

7. The VRF energy storage system according to claim 6, characterized in that, The second resonant circuit includes a second inductor, a second coil, and a second capacitor arranged sequentially. A first end of the second inductor is connected to the second switching circuit, a second end of the second inductor is connected to a first end of the second coil, a second end of the second coil is connected to a first end of the second capacitor, and a second end of the second capacitor is connected to the second switching circuit. The second coil has the same frequency as the first coil, or both the second coil and the first coil vibrate within a preset frequency range, enabling bidirectional wireless power transmission.

8. The VRF energy storage system according to any one of claims 1-7, characterized in that, The rectifier circuit is a rectifier bridge.

9. The VRF energy storage system according to any one of claims 1-7, characterized in that, The inverter circuit includes a third inductor, a switching transistor, a diode, a third capacitor, and an inverter unit. The first end of the third inductor is connected to the first output terminal of the rectifier circuit. The switching transistor is connected between the second end of the third inductor and the second output terminal of the rectifier circuit. The anode of the diode is connected to the second end of the third inductor. The cathode of the diode is connected to the first end of the third capacitor and the first input terminal of the inverter unit. The second end of the third capacitor is connected to the second output terminal of the rectifier circuit and the second input terminal of the inverter unit. The output terminal of the inverter unit is configured to connect to the load.

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