An energy storage system

Abstract

This utility model provides an energy storage system, relating to the field of energy storage technology. The energy storage system includes an energy storage converter and an energy storage device. The energy storage converter includes a first enclosure, a bidirectional AC / DC power module, a DC control circuit, and a converter control module. The energy storage device includes a battery control module, a second enclosure, and at least one energy storage battery pack disposed within the second enclosure. The bidirectional AC / DC power module is connected to a preset AC power grid and the DC control circuit. The DC control circuit is connected to a first DC interface and to the energy storage battery pack via a second DC interface. The converter control module is connected to the bidirectional AC / DC power module and the DC control circuit, and has a first communication interface. The battery control module is disposed outside the first and second enclosures, with one end connected to the first communication interface and the other end sequentially connected to a second communication interface on the second enclosure. This application reduces assembly costs and allows for separate debugging of the battery control module, thus reducing the debugging cycle.

Description

Technical Field

[0001] This utility model relates to the field of energy storage technology, and in particular to an energy storage system. Background Technology

[0002] As a key technology in the new energy field, energy storage systems play a crucial role in building new power systems and promoting energy structure transformation. With the large-scale grid connection of intermittent renewable energy sources such as wind power and photovoltaics, energy storage systems, with their flexible charging and discharging characteristics, can effectively smooth power fluctuations, provide frequency and voltage regulation support, and significantly improve the stability of grid operation and power quality.

[0003] Currently, the battery modules are typically connected to the grid via an energy storage converter, which in turn connects to a high-voltage box. The high-voltage box is located inside the battery cluster, and the battery cluster is electrically connected to the energy storage converter through the integrated high-voltage box, forming a complete charging and discharging circuit. In charging mode, the grid AC power is converted to DC power by the energy storage converter, and then charged by the high-voltage box's power distribution protection. In discharging mode, the DC power stored in the battery cluster is transmitted to the energy storage converter through the high-voltage box, where it is inverted into AC power and fed back to the grid or used by the load.

[0004] However, the existing methods involve a split design, resulting in a wide variety of system equipment, including components such as energy storage converters and battery system high-voltage boxes, which need to be installed and debugged separately. This greatly increases the workload and complexity of on-site debugging, thus extending the debugging cycle. Utility Model Content

[0005] The purpose of this application is to provide an energy storage system that saves space and assembly labor costs by allowing for separate debugging of the battery control module, thereby reducing the debugging cycle.

[0006] An energy storage system includes an energy storage converter and an energy storage device. The energy storage converter includes a first enclosure and a bidirectional AC / DC power module, a DC control circuit, and a converter control module disposed within the first enclosure. The energy storage device includes a battery control module, a second enclosure, and at least one energy storage battery pack disposed within the second enclosure and connected in series.

[0007] The AC terminal of the bidirectional AC / DC power module is used to connect to a preset AC power grid, and the DC terminal of the bidirectional AC / DC power module is connected to the DC control circuit. The DC control circuit is also connected to the first DC interface on the first housing, and the first DC interface is also connected to the at least one energy storage battery pack through the second DC interface on the second housing.

[0008] The converter control module is also connected to the control terminal of the bidirectional AC / DC power module and the control terminal of the DC control circuit. The converter control module is also connected to the first communication interface on the first enclosure. The battery control module is located outside the first enclosure and the second enclosure. One end of the battery control module is connected to the first communication interface, and the other end of the battery control module is connected to the at least one energy storage battery pack through the second communication interface on the second enclosure.

[0009] Optionally, the battery control module is disposed on a panel outside the first housing near the first communication interface. One end of the battery control module is plugged into the first communication interface, and the other end of the battery control module is connected to the second communication interface via a communication cable.

[0010] Optionally, the battery control module is disposed on a panel outside the second housing near the second communication interface. One end of the battery control module is connected to the first communication interface via a communication cable, and the other end of the battery control module is plugged into the second communication interface.

[0011] Optionally, the battery control module is located at any position outside the first housing and the second housing, and one end of the battery control module is connected to the first communication interface and the second communication interface respectively via corresponding communication lines.

[0012] Optionally, the DC control circuit includes: a DC filter circuit, a first resistor, a first DC contactor, a second DC contactor, a third DC contactor, a first fuse, a second fuse, two Hall current sensors, and a circuit breaker;

[0013] The positive and negative input terminals of the DC filter circuit are respectively connected to the positive and negative DC terminals of the bidirectional AC / DC power module. The positive output terminal of the DC filter circuit is connected to the positive input terminal of the circuit breaker in sequence through the first DC contactor, the first fuse, and a Hall current sensor. The first resistor and the second DC contactor are connected in series and then connected in parallel across the two ends of the first DC contactor.

[0014] The negative output terminal of the DC filter circuit is connected to the negative input terminal of the circuit breaker in sequence through the third DC contactor, the second fuse and another Hall current sensor. The positive and negative output terminals of the circuit breaker are respectively connected to the positive and negative pins of the first DC interface.

[0015] The first DC contactor, the second DC contactor, the third DC contactor, the two Hall current sensors, and the control terminal of the circuit breaker are all connected to the converter control module.

[0016] Optionally, the energy storage converter further includes: an AC control circuit disposed in the first enclosure, wherein the AC terminal of the bidirectional AC / DC power module is connected to the preset AC power grid through the AC control circuit; the AC control circuit is also connected to the converter control module.

[0017] Optionally, the AC control circuit includes: an AC pre-charging circuit and an AC filtering circuit. One end of the AC pre-charging circuit is connected to the preset AC power grid, and the other end of the AC pre-charging circuit is connected to the AC terminal of the bidirectional AC / DC power module through the AC filtering circuit. The control terminal of the AC pre-charging circuit is connected to the converter control module.

[0018] Optionally, the AC control circuit further includes: a plurality of Hall current sensors, wherein the plurality of Hall current sensors are connected between the AC filter circuit and the multi-phase AC pins of the AC terminal of the bidirectional AC / DC power module;

[0019] The plurality of Hall current sensors are also connected to the converter control module.

[0020] Optionally, the AC control circuit further includes: a leakage current sensor, which is connected between the preset AC power grid and one end of the AC pre-charging circuit, and the leakage current sensor is also connected to the converter control module.

[0021] Optionally, the AC control circuit further includes: a plurality of fuses connected between the preset AC power grid and the leakage current sensor.

[0022] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0023] An energy storage system utilizes a battery control module to enable communication between the converter control module in the energy storage converter and the energy storage battery pack within the energy storage device. This allows the converter control module to control the bidirectional AC / DC power conversion module and DC control circuit within the energy storage converter, thus achieving charging and discharging of the energy storage system. This simplifies the high-voltage box in the energy storage device by reducing redundant components, connecting only the battery control module to the energy storage converter and the energy storage device. This eliminates the need for contactors, fuses, high-voltage boxes, and wiring harnesses, saving significant system space, wiring, and assembly labor costs. Furthermore, the battery control module can be independently debugged, upgraded, and controlled, reducing the probability of failure and shortening the debugging cycle. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this application;

[0026] Figure 2 A schematic diagram of the structure of a DC control circuit in an energy storage system provided in this application embodiment;

[0027] Figure 3 This is a schematic diagram of another energy storage system provided in an embodiment of this application;

[0028] Figure 4 A schematic diagram of the structure of an AC control circuit in an energy storage system provided in this application embodiment;

[0029] Figure 5 A schematic diagram of the structure of an AC control circuit in another energy storage system provided in this application embodiment;

[0030] Figure 6 A schematic diagram of the structure of an AC control circuit in another energy storage system provided in this application embodiment;

[0031] Figure 7 A schematic diagram of the structure of an AC control circuit in an energy storage system is provided as an embodiment of this application;

[0032] Figure 8 This is a schematic diagram of the structure of an energy storage converter in an energy storage system provided in an embodiment of this application.

[0033] Figure label:

[0034] Energy storage system - 1000; Energy storage converter - 100; Energy storage device - 200; First enclosure - 101; Bidirectional AC / DC power module - 102; DC control circuit - 103; Converter control module - 104; DC filter circuit - 105; AC control circuit - 106; AC precharge circuit - 107; AC filter circuit - 108; Leakage current sensor - 109; Battery control module - 201; Second enclosure - 202; Energy storage battery pack - 203; First resistor - R1; First DC contactor - S1; Second DC contactor - S2; Third DC contactor - S3; First fuse - FU1; Second fuse - FU2; Two Hall current sensors - HALL; Circuit breaker - QF; Fuse - FU. Detailed Implementation

[0035] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0036] The components of the present invention embodiments described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0037] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0038] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0039] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0040] Currently, energy storage converters are connected to the power grid and then to a high-voltage box, which is located inside the battery cluster. The battery cluster is electrically connected to the energy storage converter through the integrated high-voltage box, forming a complete charging and discharging circuit. The high-voltage box's location within the battery cluster makes commissioning and testing complex and time-consuming. Furthermore, the circuitry within the high-voltage box includes circuit breakers, DC contactors, fuses, Hall effect current sensors, and a battery control module. There is overlap between the circuitry in the high-voltage box and the circuitry within the energy storage converter, leading to circuit redundancy and increased manufacturing costs. Therefore, this application provides an energy storage system comprising an energy storage converter and an energy storage device. The energy storage converter includes a first enclosure and a bidirectional AC / DC power module, a DC control circuit, and a converter control module housed within the first enclosure. The energy storage device includes a battery control module, a second enclosure, and at least one energy storage battery pack connected in series within the second enclosure. This application eliminates the high-voltage box and places the battery control module in the high-voltage box outside the second box, which reduces the manufacturing cost of the energy storage system. Furthermore, the battery control module can be debugged separately, which reduces the complexity of debugging and shortens the debugging cycle.

[0041] To clearly describe the energy storage system provided in the embodiments of this application, the energy storage system will be described below in conjunction with several accompanying drawings. Figure 1 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this application, as shown below. Figure 1 As shown, the energy storage system 1000 includes: an energy storage converter 100 and an energy storage device 200. The energy storage converter 100 includes: a first housing 101, and a bidirectional AC / DC power module 102, a DC control circuit 103 and a converter control module 104 disposed in the first housing. The energy storage device 200 includes: a battery control module 201, a second housing 202 and at least one energy storage battery pack 203 disposed in the second housing and connected in series.

[0042] The AC terminal of the bidirectional AC / DC power module 102 is used to connect to a preset AC power grid, and the DC terminal of the bidirectional AC / DC power module 102 is connected to the DC control circuit 103. The DC control circuit 103 is also connected to the first DC interface on the first housing 101. The first DC interface is also connected to at least one energy storage battery pack 203 through the second DC interface on the second housing 202.

[0043] The converter control module 104 is also connected to the control terminal of the bidirectional AC / DC power module 102 and the control terminal of the DC control circuit 103. The converter control module 104 is also connected to the first communication interface on the first housing 101. The battery control module 201 is located outside the first housing 101 and the second housing 202. One end of the battery control module 201 is connected to the first communication interface, and the other end of the battery control module 201 is connected to at least one energy storage battery pack 203 through the second communication interface on the second housing 202.

[0044] Optionally, the first enclosure 101 can be made of metal or non-metal. The first enclosure 101 houses a bidirectional AC / DC power module 102, a DC control circuit 103, and a converter control module 104. The AC terminal of the bidirectional AC / DC power module 102 is connected to a preset AC power grid, and the DC terminal of the bidirectional AC / DC power module 102 is connected to the DC control circuit 103. This circuit converts power between AC and DC, converting AC power from the preset AC power grid to DC power for energy storage in the energy storage battery pack 203, or converting DC power from the energy storage battery pack 203 to AC power for feedback to the preset AC power grid or for use by local loads. When the preset AC power grid is a three-phase grid, the bidirectional AC / DC power module 102 is a three-phase four-arm converter. The DC control circuit 103 adjusts the output voltage of the bidirectional AC / DC power module 102 to protect the circuitry within the energy storage converter 100, and detects the current in the circuit to prevent malfunctions in the energy storage converter 100 due to excessive current. The converter control module 104 is also connected to the control terminal of the bidirectional AC / DC power module 102 and the control terminal of the DC control circuit 103. The converter control module 104 is also connected to the first communication interface on the first housing 101. The battery control module 201 is located outside the first housing 101 and the second housing 202. One end of the battery control module 201 is connected to the first communication interface, and the other end of the battery control module 201 is connected to at least one energy storage battery pack 203 via the second communication interface on the second housing 202. Data collected by sensors inside the bidirectional AC / DC power module 102 and the DC control circuit 103 is acquired, and the switches inside the bidirectional AC / DC power module 102 and the DC control circuit 103 are controlled to open and close, enabling the energy storage converter 100 to operate normally. Simultaneously, the battery control module 201 is connected via the first communication interface to acquire voltage, current, and temperature information of at least one energy storage battery pack 203 collected by the battery control module 201 through the second communication interface. Based on this information, the converter control module 104 controls the switches inside the bidirectional AC / DC power module 102 and the DC control circuit 103 to prevent damage to the energy storage battery pack 203. The battery control module 201 can be a battery control unit (BCU).

[0045] Optionally, the other end of the battery control module 201 is connected to at least one energy storage battery pack 203 via a second communication interface on the second housing 202. Specifically, the second communication interface connects to the battery management unit (BMU) within the at least one energy storage battery pack 203 to acquire voltage, current, and temperature data of the energy storage battery pack. The positive terminal of the energy storage battery pack 203 is connected to the positive terminal of the DC control circuit 103, and the negative terminal of the energy storage battery pack is connected to the negative terminal of the DC control circuit 103. The energy storage battery pack 203 is the smallest detachable energy storage module in the battery system, consisting of four 1P13S battery modules, a data acquisition harness, a BMU module, an explosion-proof valve, a fuse, a liquid cooling plate, a high-voltage safety switch (Manual Service Disconnect, MSD), and other related electrical and structural components. The second housing 202 is manufactured using a die-casting process, with the liquid cooling channel integrally formed.

[0046] Optionally, the battery control module 201 is disposed on a panel outside the first housing 101 near the first communication interface. One end of the battery control module 201 is plugged into the first communication interface, and the other end of the battery control module 201 is connected to the second communication interface via a communication cable. In this configuration, the battery control module 201 and the first housing 101 do not require a communication cable connection; communication can be achieved simply by plugging them in.

[0047] Optionally, the battery control module 201 is mounted on a panel outside the second housing 202 near the second communication interface. One end of the battery control module 201 is connected to the first communication interface via a communication cable, and the other end of the battery control module 201 is plugged into the second communication interface. In this configuration, the battery control module 201 and the second housing 202 do not require a communication cable connection; communication can be achieved simply by plugging them in.

[0048] Optionally, the battery control module 201 is located at any position outside the first housing 101 and the second housing 202, and one end of the battery control module 201 is connected to the first communication interface and the second communication interface via corresponding communication lines.

[0049] In this embodiment, a battery control module enables communication between the converter control module in the energy storage converter device and the energy storage battery pack within the energy storage system. This allows the converter control module to control the bidirectional AC / DC power conversion module and DC control circuit in the energy storage converter device, thus achieving charging and discharging of the energy storage system. This simplifies the high-voltage box in the energy storage device by connecting it only to the converter device and the energy storage device via the battery control module. This reduces the number of contactors, fuses, high-voltage boxes, and wiring harnesses in the high-voltage box, saving significant system space, wiring, and assembly labor costs. Furthermore, the battery control module can be independently debugged, upgraded, and controlled, reducing the probability of failure and shortening the debugging cycle.

[0050] Based on the above embodiments, this application also provides a schematic diagram of the structure of a DC control circuit in an energy storage system. Figure 2 This application provides a schematic diagram of the structure of a DC control circuit in an energy storage system, as shown in the embodiment. Figure 2 As shown, the DC control circuit 103 includes: a DC filter circuit 105, a first resistor R1, a first DC contactor S1, a second DC contactor S2, a third DC contactor S3, a first fuse FU1, a second fuse FU2, two Hall current sensors HALL, and a circuit breaker QF.

[0051] The positive and negative input terminals of the DC filter circuit 105 are connected to the positive and negative DC terminals of the bidirectional AC / DC power module 102, respectively. The positive output terminal of the DC filter circuit 105 is connected to the positive input terminal of the circuit breaker QF in sequence through the first DC contactor S1, the first fuse FU1, and a Hall current sensor HALL. The first resistor R1 and the second DC contactor S2 are connected in series and then in parallel across the two ends of the first DC contactor S1.

[0052] The negative output terminal of the DC filter circuit 105 is connected to the negative input terminal of the circuit breaker QF in sequence through the third DC contactor S3, the second fuse FU2 and another Hall current sensor HALL. The positive and negative output terminals of the circuit breaker QF are connected to the positive and negative pins of the first DC interface, respectively.

[0053] The control terminals of the first DC contactor S1, the second DC contactor S2, the third DC contactor S3, the two Hall current sensors HALL, and the circuit breaker QF are all connected to the converter control module 104.

[0054] Optionally, the DC filter circuit 105 is used to filter out high-frequency noise, ripple, and harmonics in the DC side voltage or current. The DC filter circuit 105 can be a DC electromagnetic compatibility (EMC) filter circuit. The first resistor R1 is a pre-charge resistor, used to limit the initial current when the energy storage battery pack is charging a preset AC grid or load. The control terminals of the first DC contactor S1, the second DC contactor S2, and the third DC contactor S3 are respectively connected to the converter control module 104. The DC control circuit 103 is turned on by controlling the first DC contactor S1, the second DC contactor S2, and the third DC contactor S3. The first fuse FU1 and the second fuse FU2 are used to protect the DC control circuit 103 to prevent damage to the circuit due to excessive current. The control terminal of the circuit breaker QF is connected to the converter control module 104. The circuit breaker QF is the main switch of the entire DC control circuit. The entire DC control circuit is turned on or off by controlling the circuit breaker QF.

[0055] Both Hall current sensors (HALL) and the control terminal of circuit breaker QF are connected to the converter control module 104. One Hall current sensor (HALL) is used to detect the current in the first branch, and the other Hall current sensor (HALL) is used to detect the current in the second branch, so that the converter control module 104 controls the contactors and circuit breakers inside the DC control circuit based on the current detected by the Hall current sensors (HALL). The first branch is formed by connecting the positive and negative input terminals of the DC filter circuit 105 to the positive and negative DC terminals of the bidirectional AC / DC power module 102, respectively. The positive output terminal of the DC filter circuit 105 is connected to the positive input terminal of the circuit breaker QF in sequence through the first DC contactor S1, the first fuse FU1, and a Hall current sensor (HALL). The first resistor R1 and the second DC contactor S2 are connected in series and then in parallel across the two ends of the first DC contactor S1, forming a branch. The second branch is formed by connecting the negative output terminal of the DC filter circuit 105 to the negative input terminal of the circuit breaker QF in sequence through the third DC contactor S3, the second fuse FU2, and another Hall current sensor (HALL).

[0056] In this embodiment, the DC control circuit includes: a DC filter circuit, a first resistor, a first DC contactor, a second DC contactor, a third DC contactor, a first fuse, a second fuse, two Hall current sensors, and a circuit breaker. This application uses Hall current sensors to detect the current in the DC control circuit, preventing excessive current from damaging the circuit, and uses fuses for overcurrent protection to prevent circuit damage.

[0057] Based on the above embodiments, this application also provides a schematic diagram of the structure of another energy storage system. Figure 3 A schematic diagram of another energy storage system provided in this application embodiment is shown below. Figure 3 As shown, the energy storage converter 100 also includes: an AC control circuit 106 disposed in the first housing 101, the AC terminal of the bidirectional AC / DC power module 102 being connected to a preset AC power grid through the AC control circuit 106; the AC control circuit 106 is also connected to the converter control module 104.

[0058] The AC control circuit 106 is also connected to the converter control module 104, so that the converter control module 104 controls the conduction and disconnection of the AC control circuit. The AC control circuit 106 is used to protect the energy storage converter and prevent short circuit caused by large current when connected to the preset AC grid. The AC control circuit 106 is also used to filter out high-frequency noise and prevent interference to the preset AC grid or load.

[0059] In this embodiment, an AC control circuit is installed between the bidirectional AC / DC power module and the preset AC grid to prevent excessive current from the preset AC grid from damaging the current and to improve the safety of circuit operation.

[0060] Based on the above embodiments, this application also provides a schematic diagram of the structure of an AC control circuit in an energy storage system. Figure 4 This application provides a schematic diagram of the structure of an AC control circuit in an energy storage system, as shown in the embodiment. Figure 4 As shown, the AC control circuit 106 includes: an AC pre-charging circuit 107 and an AC filter circuit 108. One end of the AC pre-charging circuit 107 is connected to a preset AC power grid, and the other end of the AC pre-charging circuit 107 is connected to the AC terminal of the bidirectional AC / DC power module 102 through the AC filter circuit 108. The control terminal of the AC pre-charging circuit 107 is connected to the converter control module 103.

[0061] Optionally, the AC pre-charging circuit 107 is used to suppress the surge current when the AC side is powered on, and to protect the energy storage AC device from the impact of instantaneous large current. When the preset AC power grid is a three-phase power grid, the AC pre-charging circuit 107 may include four resistors and four switches. One resistor and one switch are connected in parallel, and the four sets of parallel switches are respectively connected to the circuit where the three-phase power supply and the neutral line are located.

[0062] Optionally, the AC filter circuit 108 is used to filter out high-frequency switching noise. When the preset AC power grid is a three-phase power grid, the AC pre-charging circuit 107 may include four inductors and four capacitors. The four inductors are respectively connected to the three-phase circuit and the circuit where the neutral line is located. The three-phase circuit and the neutral line are respectively connected to one end of the four capacitors, and the other end of the four capacitors are connected to...

[0063] In this embodiment, the AC control circuit includes an AC pre-charging circuit and an AC filtering circuit, which can protect the energy storage AC device from damage caused by excessive current, and can also filter out high-frequency noise to prevent noise interference.

[0064] Based on the above embodiments, this application also provides a schematic diagram of the structure of an AC control circuit in an energy storage system. Figure 5 A schematic diagram of the structure of an AC control circuit in another energy storage system provided in this application embodiment is shown below. Figure 5 As shown, the AC control circuit 106 also includes: multiple Hall current sensors HALL, which are connected between the AC filter circuit 108 and the multi-phase AC pins of the AC terminal of the bidirectional AC / DC power module 102.

[0065] Multiple Hall current sensors (HALL) are also connected to the converter control module (104).

[0066] The Hall current sensor (HALL) is used to detect the current in the energy storage converter. The Hall current sensor (HALL) is connected to the converter control module 104, and feeds back the monitored current to the converter control module 104, enabling the converter control module 104 to control the energy storage converter based on the current feedback from the Hall current sensor (HALL). When the preset AC grid is a three-phase grid, four Hall current sensors (HALL) are used, connected to the three-phase circuit and the circuit containing the neutral wire, respectively, to detect the current in the three-phase circuit and the circuit containing the neutral wire.

[0067] Based on the above embodiments, this application also provides a schematic diagram of the structure of an AC control circuit in an energy storage system. Figure 6 A schematic diagram of the structure of an AC control circuit in another energy storage system provided in this application embodiment is shown below. Figure 6 As shown, the AC control circuit 106 also includes a leakage current sensor 109, which is connected between a preset AC power grid and one end of the AC pre-charging circuit 107. The leakage current sensor 109 is also connected to the converter control module 104.

[0068] The leakage current sensor 109 is used to detect the leakage current in the energy storage converter. The leakage current sensor 109 is connected to the converter control module 104. When the leakage current sensor 109 detects the leakage current, it feeds back the signal to the converter control module 104, so that the converter control module 104 controls the energy storage converter based on the leakage current fed back by the leakage current sensor 109.

[0069] Based on the above embodiments, this application also provides a schematic diagram of the structure of an AC control circuit in an energy storage system. Figure 7 A schematic diagram of the structure of an AC control circuit in an energy storage system provided as an embodiment of this application is shown below. Figure 7 As shown, the AC control circuit also includes multiple fuses FU, which are connected between the preset AC power grid and the leakage current sensor 109.

[0070] When the preset AC power grid is a three-phase power grid, there are three fuses FU, which are connected to the three-phase circuit respectively. When the current in any circuit of the three-phase circuit is too large, the fuse FU corresponding to that circuit will open to protect the circuit.

[0071] In this embodiment of the application, by setting a fuse in the AC control circuit, the AC control circuit can be protected to avoid damage to the circuit due to excessive current.

[0072] The following is a schematic diagram of the structure of an energy storage converter in an energy storage system provided in an embodiment of this application, with reference to the accompanying drawings. Figure 8This application provides a schematic diagram of the structure of an energy storage converter in an energy storage system, as shown in the embodiments. Figure 8 As shown, the energy storage converter 100 includes: a first enclosure 101, and a bidirectional AC / DC power module 102, a DC control circuit 103, a converter control module 104, and an AC control circuit 106 disposed within the first enclosure. The DC control circuit 103 includes: a DC filter circuit 105, a first resistor R1, a first DC contactor S1, a second DC contactor S2, a third DC contactor S3, a first fuse FU1, a second fuse FU2, two Hall current sensors HALL, and a circuit breaker QF. The AC control circuit 106 includes: an AC precharge circuit 107, an AC filter circuit 108, multiple Hall current sensors HALL, a leakage current sensor 109, and multiple fuses FU.

[0073] Optionally, when the preset AC power grid is a three-phase AC power grid, the AC pre-charging circuit 107 may include four resistors and four switches, with one resistor and one switch connected in parallel. The four sets of parallel switches are respectively connected to the circuits containing the three-phase power supply and the neutral wire. The AC pre-charging circuit 107 may include four inductors and four capacitors, with the four inductors respectively connected to the circuits containing the three-phase power supply and the neutral wire. The three-phase power supply and the neutral wire are respectively connected to one end of the four capacitors, and the other end of the four capacitors are connected to... Four Hall effect current sensors (HALLs) are used to detect the current in the three-phase power supply and the circuit containing the neutral wire. A leakage current sensor 109 is connected to the circuits containing the three-phase power supply and the neutral wire, and three fuses (FUs) are used to connect to the three-phase power supply and the neutral wire.

[0074] Optionally, the converter control module 104 is connected to two Hall current sensors (HALL) in the DC control circuit 103, four Hall current sensors (HALL) on the three-phase circuit, and leakage current sensor 109 to acquire and detect the current. The converter control module 104 is connected to the first DC contactor S1, the second DC contactor S2, the third DC contactor S3, and the circuit breaker QF in the DC control circuit 103, to the control terminal of the three-phase four-arm converter in the bidirectional AC / DC power module 102, and also to the switch in the AC pre-charging circuit 107 of the AC control circuit 106. The converter control module 104 controls the contactors, circuit breaker, switch, and converter based on the detected current and leakage current.

[0075] Specifically, when the energy storage system is in grid-connected operation, the DC control circuit 103 is connected to the energy storage device 200, and the energy storage converter 100 supplies power to the battery control module 201. When the energy storage converter 100 is in normal shutdown mode, it performs a self-test and enters grid-connected mode. The battery control module 201 performs a self-test and insulation test, and transmits the results to the energy storage converter 100 via communication to indicate that the battery control module 201's self-test is normal. When both the energy storage converter 100 and the battery control module 201 have performed a self-test, the system operates normally. Normally, the converter control module 104 controls the circuit breaker QF to close, enabling the energy storage converter 100 to perform DC pre-charging and grid-connected startup. The charging / discharging point switching time of the energy storage converter 100 is less than 100ms. When the preset DC grid malfunctions, it disconnects from the preset DC grid and enters a fault state. In the grid-connected state, the energy storage converter 100 can convert the DC power of the energy storage device 200 into AC power and connect it to the preset AC grid; it can also charge the AC power of the preset AC grid into the energy storage battery pack 203 of the energy storage device 200 for storage.

[0076] When the energy storage system is in off-grid operation, the DC control circuit 103 is connected to the energy storage device 200, and the energy storage converter 100 supplies power to the battery control module 201. When the energy storage converter 100 is in normal shutdown state, the energy storage converter 100 performs self-test and enters off-grid state. The battery control module 201 performs self-test and insulation test, and transmits the results to the energy storage converter 100 via communication to indicate that the battery control module 201's self-test is normal. When both the energy storage converter 100 and the battery control module 201 have normal self-test results, the converter control module 104 controls the circuit breaker QF to close and sends a start-up command to the energy storage converter 100, causing the energy storage converter 100 to perform DC pre-charging and off-grid start-up.

[0077] When the energy storage system is in standby mode, after the energy storage converter 100 is connected to the grid and turned on, it waits to receive operation commands. When the operation command is a charging command, i.e., a constant voltage charging voltage value, a constant current charging current value, and a constant power charging power value, it is necessary to determine the charging mode as constant voltage, constant current, or constant power before entering the grid-connected charging state; when the operation command is set to a discharging command, i.e., a constant current discharging current value and a constant power discharging power value, it is necessary to determine the discharging mode as constant current or constant power before entering the grid-connected discharging state.

[0078] When the energy storage system is in a fault state, and the energy storage converter 100 malfunctions, the energy storage converter 100 will immediately block the bidirectional AC / DC power module 102 and disconnect the DC-side contactor, entering a fault state. When the battery control module 201 detects a serious battery fault, such as a level 3 temperature or overvoltage alarm, it will disconnect the DC-side circuit breaker and notify the energy storage converter 100 via communication. The energy storage converter 100 will then block the pulse and control the DC control circuit 103 to disconnect, thereby ensuring the AC and DC connections are separated. The energy storage converter 100 and battery control module 201 will continuously monitor whether the fault has been cleared. If the fault has not been cleared, the fault state will remain. If a serious fault is resolved, the circuit breaker QF in the DC control circuit 103 needs to be manually closed.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. An energy storage system, characterized by, The energy storage system includes: an energy storage converter and an energy storage device, wherein the energy storage converter includes: a first enclosure, and a bidirectional AC / DC power module, a DC control circuit and a converter control module disposed in the first enclosure; the energy storage device includes: a battery control module, a second enclosure and at least one energy storage battery pack disposed in the second enclosure and connected in series. The AC terminal of the bidirectional AC / DC power module is used to connect to a preset AC power grid, and the DC terminal of the bidirectional AC / DC power module is connected to the DC control circuit. The DC control circuit is also connected to the first DC interface on the first housing, and the first DC interface is also connected to the at least one energy storage battery pack through the second DC interface on the second housing. The converter control module is also connected to the control terminal of the bidirectional AC / DC power module and the control terminal of the DC control circuit. The converter control module is also connected to the first communication interface on the first enclosure. The battery control module is located outside the first enclosure and the second enclosure. One end of the battery control module is connected to the first communication interface, and the other end of the battery control module is connected to the at least one energy storage battery pack through the second communication interface on the second enclosure.

2. The energy storage system of claim 1, wherein, The battery control module is located on a panel outside the first housing near the first communication interface. One end of the battery control module is plugged into the first communication interface, and the other end of the battery control module is connected to the second communication interface via a communication cable.

3. The energy storage system of claim 1, wherein, The battery control module is located on a panel outside the second housing near the second communication interface. One end of the battery control module is connected to the first communication interface via a communication cable, and the other end of the battery control module is plugged into the second communication interface.

4. The energy storage system of claim 1, wherein, The battery control module is located at any position outside the first housing and the second housing, and one end of the battery control module is connected to the first communication interface and the second communication interface respectively via corresponding communication lines.

5. The energy storage system of claim 1, wherein, The DC control circuit includes: a DC filter circuit, a first resistor, a first DC contactor, a second DC contactor, a third DC contactor, a first fuse, a second fuse, two Hall current sensors, and a circuit breaker; The positive and negative input terminals of the DC filter circuit are respectively connected to the positive and negative DC terminals of the bidirectional AC / DC power module. The positive output terminal of the DC filter circuit is connected to the positive input terminal of the circuit breaker in sequence through the first DC contactor, the first fuse, and a Hall current sensor. The first resistor and the second DC contactor are connected in series and then connected in parallel across the two ends of the first DC contactor. The negative output terminal of the DC filter circuit is connected to the negative input terminal of the circuit breaker in sequence through the third DC contactor, the second fuse and another Hall current sensor. The positive and negative output terminals of the circuit breaker are respectively connected to the positive and negative pins of the first DC interface. The first DC contactor, the second DC contactor, the third DC contactor, the two Hall current sensors, and the control terminal of the circuit breaker are all connected to the converter control module.

6. The energy storage system of claim 1, wherein, The energy storage converter further includes: an AC control circuit disposed in the first enclosure, wherein the AC terminal of the bidirectional AC / DC power module is connected to the preset AC power grid through the AC control circuit; the AC control circuit is also connected to the converter control module.

7. The energy storage system of claim 6, wherein, The AC control circuit includes an AC pre-charging circuit and an AC filtering circuit. One end of the AC pre-charging circuit is connected to the preset AC power grid, and the other end of the AC pre-charging circuit is connected to the AC terminal of the bidirectional AC / DC power module through the AC filtering circuit. The control terminal of the AC pre-charging circuit is connected to the converter control module.

8. The energy storage system of claim 7, wherein, The AC control circuit further includes: multiple Hall current sensors, which are connected between the AC filter circuit and the multi-phase AC pins of the AC terminal of the bidirectional AC / DC power module; The plurality of Hall current sensors are also connected to the converter control module.

9. The energy storage system of claim 7, wherein, The AC control circuit further includes a leakage current sensor, which is connected between the preset AC power grid and one end of the AC pre-charging circuit, and is also connected to the converter control module.

10. The energy storage system of claim 9, wherein, The AC control circuit further includes: multiple fuses connected between the preset AC power grid and the leakage current sensor.

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