Energy storage system

Abstract

The present application discloses an energy storage system. The energy storage system comprises: a battery pack, which comprises a power supply assembly, a switch assembly, and a current sampling device, the power supply assembly being respectively coupled with the switch assembly and the current sampling device; and a converter assembly, being connected to the current sampling device by means of a first power line, and being connected to the switch assembly by means of a second power line and a grounding wire. The current sampling device, the first power line, the converter assembly, and the second power line form a first current loop; the current sampling device, the first power line, the converter assembly, and the grounding wire form a second current loop; and the switch assembly is used for controlling the first current loop and / or the second current loop to be turned on or off. In response to the first current loop being turned off and the second current loop being turned on, the current sampling device acquires a sampled current, and it is determined on the basis of the sampled current that grounding of the battery pack has been good. According to the present application, the current sampling device acquires the sampled current when the second current loop is turned on so as to quickly determine whether the grounding of the battery pack has been good.

Description

An energy storage system CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Chinese patent application No. 2024102578236, filed on March 6, 2024, entitled “A Kind of Energy Storage System,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the field of energy storage technology, and in particular to an energy storage system. Background Art

[0003] As the green development strategy of carbon neutrality continues to gain traction, the energy storage business will continue to expand, especially with the promotion and deployment of small energy storage systems. These systems are becoming increasingly widespread in various scenarios and for various needs. The promotion and deployment of energy storage battery systems must be combined with the use of energy storage inverter systems. Energy storage battery systems store energy, while energy storage inverter systems use energy. With the widespread use of battery systems, inverter systems are also gaining widespread use. This places higher demands on the connection design of stackable energy storage battery systems and inverter systems.

[0004] Currently, integrated energy storage systems are typically installed in a stacked configuration, with the inverter placed on the top layer and multiple battery packs (PACKs) arranged below. The electrical connection between the inverter and battery packs is achieved through mechanical plug-in or side cable connections. The power connections between the battery pack and inverter primarily consist of three wires: BUS+, BUS-, and PE, which transmit positive voltage, negative voltage, and ground, respectively.

[0005] In actual operation, if the BUS+ or BUS- between the battery pack and the inverter is poorly connected or forgotten, the energy storage device will function abnormally, which is easy to identify. However, if the PE is forgotten or has poor contact, the energy storage device can still operate normally without a grounding detection function. At this time, the battery casing may become electrically charged, posing a safety hazard. Summary of the Invention

[0006] The present application provides an energy storage system that can detect whether the grounding wire between the battery pack and the inverter is abnormal, and then effectively prevent the battery casing from becoming electrically charged and causing safety hazards by detecting the abnormality of the grounding wire.

[0007] The present application provides an energy storage system, which includes:

[0008] A battery pack, comprising a power supply assembly, a switch assembly, and a current sampling device, wherein the power supply assembly is coupled to the switch assembly and the current sampling device respectively;

[0009] The current conversion component is connected to the current sampling device via a first power line, and is connected to the switch component via a second power line and a ground line; wherein the current sampling device, the first power line, the current conversion component, and the second power line constitute a first current loop; and the current sampling device, the first power line, the current conversion component, and the ground line constitute a second current loop;

[0010] The switch component is used to control the first current loop and / or the second current loop to be turned on or off;

[0011] In response to the first current loop being cut off and the second current loop being turned on, the current sampling device obtains a sampling current and determines whether the battery pack is well grounded based on the sampling current; the sampling current is the loop current of the second current loop.

[0012] Furthermore, the power supply assembly includes:

[0013] DCDC power supply, used to provide power supply voltage;

[0014] A transformer, wherein a first end and a second end of the transformer are connected to a first end and a second end of a DCDC power supply respectively; wherein the first end and the second end of the transformer are same-named ends;

[0015] The power circuit, the third end and the fourth end of the transformer are respectively connected to the power circuit, the switch component is connected in series between the power circuit and the second power line, the switch component is also connected in series between the power circuit and the ground line, and the current sampling device is connected in series between the power circuit and the first power line.

[0016] Furthermore, the power supply assembly further includes:

[0017] a first capacitor, wherein a first end of the first capacitor is connected to the first end of the DCDC power supply, a second end of the first capacitor is connected to the second end of the DCDC power supply, and the second end of the first capacitor is further connected to the second end of the transformer;

[0018] A first switching element, wherein a first end of the first switching element is connected to a first end of the first capacitor, and a second end of the first switching element is connected to a first end of the transformer.

[0019] Furthermore, the switch assembly includes:

[0020] a second switch element, wherein a first end of the second switch element is connected to the first end of the ground line, the first end of the second switch element is also connected to the first ground end, and a second end of the second switch element is connected to the second ground end;

[0021] A third switching element, wherein a first end of the third switching element is connected to the second end of the second switching element, and a second end of the third switching element is connected to the first end of the second power line.

[0022] Furthermore, the power circuit includes a second capacitor, a third capacitor, a fourth capacitor and a first resistor;

[0023] A first end of the second capacitor is connected to the third end of the transformer, a second end of the second capacitor is connected to the fourth end of the transformer, and the second end of the second capacitor is also connected to the second ground end, a first end of the third capacitor is connected to the first end of the second capacitor, and the second end of the third capacitor is connected to the first ground end, a first end of the fourth capacitor is connected to the second end of the third capacitor, and the second end of the fourth capacitor is connected to the second end of the second capacitor, a first end of the current sampling device is connected to the first end of the second capacitor, and the second end of the current sampling device is connected to the first end of the first power line, a first end of the first resistor is connected to the second end of the current sampling device, a second end of the first resistor is connected to the second end of the third capacitor, and the second end of the first resistor is also connected to the first end of the ground line.

[0024] Furthermore, the current sampling device is a sampling resistor.

[0025] Furthermore, the converter assembly includes a fifth capacitor, a sixth capacitor, a seventh capacitor, a second resistor, and an inverter;

[0026] The first end of the second resistor is connected to the second end of the first power line, the second end of the second resistor is connected to the second end of the ground line, and the second end of the second resistor is also connected to the first ground end. The first end of the fifth capacitor is connected to the first end of the second resistor, and the second end of the fifth capacitor is connected to the second end of the second resistor. The first end of the sixth capacitor is connected to the second end of the fifth capacitor, and the second end of the sixth capacitor is connected to the second ground end. The second end of the sixth capacitor is also connected to the second end of the second power line. The first end of the inverter is connected to the first end of the fifth capacitor, and the second end of the inverter is connected to the second end of the sixth capacitor. The seventh capacitor is connected in parallel at both ends of the inverter.

[0027] Furthermore, the first grounding end is an earth ground wire, and the second grounding end is a power ground wire.

[0028] Furthermore, the battery pack further includes:

[0029] A sampling, holding and amplifying circuit, wherein the first input terminal and the second input terminal of the sampling, holding and amplifying circuit are respectively connected to the first terminal and the second terminal of the current sampling device, and the current signal is collected by the current sampling device and amplified;

[0030] The filter circuit has an input end connected to the output end of the sampling, holding and amplifying circuit, and is used to filter the current signal output by the sampling, holding and amplifying circuit.

[0031] Furthermore, the energy storage system also includes a digital signal processor, the input end of the digital signal processor is connected to the output end of the filter circuit, receives the current signal output by the filter circuit, and determines whether the battery pack is well grounded based on the current signal.

[0032] Furthermore, the energy storage system includes a plurality of battery packs, and the plurality of battery packs are arranged in parallel with the converter assembly;

[0033] In response to abnormal grounding of any one of the multiple battery packs, the digital signal processor generates an alarm signal and controls the energy storage system to stop.

[0034] Furthermore, the multiple battery packs are stacked in sequence, and the converter assembly is arranged on the top layer.

[0035] Furthermore, the energy storage system also includes a plurality of digital signal processors, which are respectively arranged in the plurality of battery packs to connect the sampling, holding and amplifying circuits and the filtering circuits of the corresponding battery packs, and each of the digital signal processors is used to perform status detection on the ground wire of the corresponding battery pack.

[0036] Furthermore, the energy storage system also includes a single digital signal processor connected in parallel to the output ends of the filter circuits of the multiple battery packs, and the digital signal processor is used to perform status detection on the ground wires of the multiple battery packs respectively.

[0037] Furthermore, the power supply component also includes a first capacitor, and the current signal is the discharge current released by the first capacitor. The current signal is sequentially amplified by the sampling and holding and amplifying circuit and filtered by the filtering circuit and sent to the digital signal processor. The digital signal processor is used to receive the current signal and determine whether the ground wire is well connected.

[0038] Different from the existing technology, the present application sets a current sampling device, and the first power line coupling the battery pack and the converter component, the ground line and the current sampling device form a second current loop, that is, the ground loop of the energy storage system. When the second current loop is turned on, the sampling current under the loop is obtained through the current sampling device. The size of the sampling current can be used to quickly determine whether the current battery pack is abnormally grounded.

[0039] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0041] FIG1 is a schematic structural diagram of a first embodiment of an energy storage system of the present application;

[0042] FIG2 is a schematic structural diagram of a second embodiment of the energy storage system of the present application;

[0043] FIG3 is a schematic structural diagram of the third embodiment of the energy storage system of the present application. DETAILED DESCRIPTION

[0044] To enable those skilled in the art to better understand the technical solutions of this application, the energy storage system provided by this application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It is understood that the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of this application.

[0045] The terms "first," "second," and the like in this application are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0046] In order to solve the problem in the existing technology that the energy storage integrated machine cannot accurately and quickly determine whether the grounding wire is forgotten or has poor contact, and there is a risk that the battery casing may become electrified, creating a safety hazard, the present application provides an energy storage system, which can quickly and accurately determine whether the grounding wire is abnormal by sampling the current size.

[0047] Please refer to Figure 1, which is a schematic diagram of the structure of the first embodiment of the energy storage system of the present application. As shown in Figure 1, the energy storage system 1 includes a coupled battery pack 10 and a converter assembly 20. The battery pack 10 includes a power supply assembly 11, a switch assembly 12, and a current sampling device 13. The power supply assembly 11 is coupled to the switch assembly 12 and the current sampling device 13.

[0048] The electrical connection between the converter assembly 20 and the battery pack 10 is achieved by mechanical plug-in or side cable connection. Specifically, the converter assembly 20 and the battery pack 10 of this embodiment are coupled via a first power line 30 , a second power line 40 , and a ground line 50 .

[0049] The converter component 20 is connected to the current sampling device 13 through the first power line 30, and is connected to the switch component 12 through the second power line 40 and the ground line 50. The current sampling device 13, the first power line 30, the converter component 20 and the second power line 40 constitute a first current loop, and the current sampling device 13, the first power line 30, the converter component 20 and the ground line 50 constitute a second current loop. The switch component 12 is used to control the first current loop and / or the second current loop to be turned on or off.

[0050] When the switch component 12 controls the first current loop to be cut off and controls the second current loop to be turned on, the current sampling device 13 obtains a sampled current and determines whether the battery pack 10 is well grounded based on the sampled current, wherein the sampled current is the operating current of the second current loop.

[0051] In conjunction with Figure 1, further reference is made to Figure 2, which is a schematic structural diagram of a second embodiment of the energy storage system of the present application. As shown in Figure 2, the power supply assembly 11 includes a DC-DC power supply 111, a transformer 112, a power circuit 113, a first capacitor C1, and a first switching element RLY1. The DC-DC power supply 111 is used to provide a power supply voltage, and the transformer 112 is used to boost the power supply voltage to a preset voltage, which is related to the operating voltage of the converter assembly 20. Optionally, the power supply voltage in this embodiment can be 48V, and the preset voltage can range from 350V to 400V.

[0052] Specifically, the first and second ends of the transformer 112 are connected to the first and second ends of the DC / DC power supply 111, respectively. The third and fourth ends of the transformer 112 are connected to the power circuit 113, respectively. The switch component 12 is connected in series with the power circuit 113 and the second power line 40, so that the power circuit 113 is coupled to the second power line 40 through the switch component 12. The switch component 12 is also connected in series with the power circuit 113 and the ground line 50, so that the power circuit 113 is coupled to the ground line 50 through the switch component 12. The current sampling device 13 is connected in series between the power circuit 113 and the first power line 30, so that the power circuit 113 is coupled to the second power line 40 through the current sampling device 13. The first and second ends of the transformer 112 are like-ends, and the first and third ends of the transformer 112 are different-ends.

[0053] A first end of the first capacitor C1 is connected to a first end of the DCDC power supply 111, a second end of the first capacitor C1 is connected to a second end of the DCDC power supply 111, and the second end of the first capacitor C1 is also connected to a second end of the transformer 112. A first end of the first switching element RLY1 is connected to a first end of the first capacitor C1, and a second end of the first switching element RLY1 is connected to a first end of the transformer 112.

[0054] The first and second terminals of the first switching element RLY1 are connected in series via a switch. When the switch between the first and second terminals of the first switching element RLY1 is disconnected, that is, the first switching element RLY1 is off, the DCDC power supply 111 charges the first capacitor C1. When the switch between the first and second terminals of the first switching element RLY1 is closed, that is, the first switching element RLY1 is on, the first capacitor C1 releases the stored current.

[0055] Optionally, the first switching element RLY1 of this embodiment can be a relay, particularly a four-pin relay. The third terminal of the first switching element RLY1 is connected to ground (GND), which can be considered the reference ground in the circuit. The third and fourth terminals of the first switching element RLY1 are connected in series via a resistor. The fourth terminal of the first switching element RLY1 can be further connected to a peripheral circuit consisting of other load components to provide a buffered operation and prevent excessive startup current from damaging the converter component 20 connected to the battery pack 10.

[0056] As shown in Figure 2, the switch component 12 includes a second switch element RLY2 and a third switch element RLY3, wherein the second switch element RLY2 and the third switch element RLY3 are respectively coupled to different power lines to form different current loops. The switch component 12 controls the conduction or cutoff of different current loops by controlling the conduction or cutoff of the second switch element RLY2 and the conduction or cutoff of the third switch element RLY3.

[0057] Specifically, the first end of the second switching element RLY2 is connected to the first end of the ground line 50, and the first end of the second switching element RLY2 is also connected to the first ground end, and the second end of the second switching element RLY2 is connected to the second ground end; the first end of the third switching element RLY3 is connected to the second end of the second switching element RLY2, and the second end of the third switching element RLY3 is connected to the first end C1 of the second power line 40.

[0058] The first grounding terminal may be specifically an earth ground wire EGND, which is used to guide the current of the battery casing of the energy storage system 1 to the earth, ensuring that the voltage of the battery casing is below 36V, that is, meeting the safety voltage of the human body and ensuring human contact safety.

[0059] The second ground terminal may specifically be a power ground line PGND, which is used in a high-power circuit 113 , such as a motor drive circuit, a solenoid valve drive circuit, etc., as a discharge channel for dangerous current.

[0060] Optionally, the second switching element RLY2 and the third switching element RLY3 of this embodiment can be relays, in particular, four-pin relays, the first end and the second end of the second switching element RLY2 are connected in series through a switch, and the third end and the fourth end of the second switching element RLY2 are connected in series through a resistor, for connecting to a peripheral circuit; the first end and the second end of the third switching element RLY3 are connected in series through a switch, and the third end and the fourth end of the third switching element RLY3 are connected in series through a resistor, for connecting to a peripheral circuit.

[0061] The power circuit 113 specifically includes a second capacitor C2 , a third capacitor C3 , a fourth capacitor C4 and a first resistor R1 .

[0062] A first end of the second capacitor C2 is connected to the third end of the transformer 112, a second end of the second capacitor C2 is connected to the fourth end of the transformer 112, and the second end of the second capacitor C2 is also connected to the second ground terminal. A first end of the third capacitor C3 is connected to the first end of the second capacitor C2, and the second end of the third capacitor C3 is connected to the first ground terminal. A first end of the fourth capacitor C4 is connected to the second end of the third capacitor C3, and the second end of the fourth capacitor C4 is connected to the second end of the second capacitor C2. A first end of the current sampling device 13 is connected to the first end of the second capacitor C2, and a second end of the current sampling device 13 is connected to the first end A1 of the first power line 30. A first end of the first resistor R1 is connected to the second end of the current sampling device 13, and a second end of the first resistor R1 is connected to the second end of the third capacitor C3. The second end of the first resistor R1 is also connected to the first end B1 of the ground line 50.

[0063] The converter assembly 20 includes a fifth capacitor C5 , a sixth capacitor C6 , a seventh capacitor C7 , a second resistor R2 , and an inverter 21 .

[0064] Among them, the first end of the second resistor R2 is connected to the second end A2 of the first power line 30, the second end of the second resistor R2 is connected to the second end B2 of the ground line 50, and the second end of the second resistor R2 is also connected to the first ground end. The first end of the fifth capacitor C5 is connected to the first end of the second resistor R2, and the second end of the fifth capacitor C5 is connected to the second end of the second resistor R2. The first end of the sixth capacitor C6 is connected to the second end of the fifth capacitor C5, and the second end of the sixth capacitor C6 is connected to the second ground end. The second end of the sixth capacitor C6 is also connected to the second end C2 of the second power line 40. The first end of the inverter 21 is connected to the first end of the fifth capacitor C5, and the second end of the inverter 21 is connected to the second end of the sixth capacitor C6. The seventh capacitor C7 is connected in parallel at both ends of the inverter.

[0065] Optionally, the current sampling device 13 of this embodiment is a sampling resistor, wherein the sampling resistor selected in this embodiment has the characteristics of high detection accuracy and low delay.

[0066] Specifically, the end of the first power line 30 connected to the sampling resistor is defined as the A1 end, the end of the first power line 30 connected to the inverter 21 is defined as the A2 end, the end of the grounding line 50 connected to the first resistor R1 is defined as the B1 end, and the end of the grounding line 50 connected to the second resistor R2 is defined as the B2 end.

[0067] When the first switch element RLY1 is controlled to be closed, the second switch element RLY2 is opened, and the third switch element RLY3 is closed, the first current loop connected to the second power line 40 is disconnected, the first capacitor C1 releases current, and the current flows through the sampling resistor, the A1 terminal, the first power line 30, the A2 terminal, the inverter 21, the B2 terminal, the B1 terminal, and the sampling resistor in sequence to form a second current loop.

[0068] Specifically, when the second current loop is turned on, the power supply voltage provided by the DCDC power supply 111 is converted into a current and released through the first capacitor C1. The current flows through the second current loop and is used to support the circuit elements on the second current loop to operate. That is, the sampling single current collected by the sampling resistor is the loop current flowing in the closed state in the second current loop.

[0069] Therefore, the current sampling device 13 samples the discharge current and can determine the connection status of the ground wire 50 by determining the discharge current.

[0070] Alternatively, in other embodiments, the current sampling device 13 may be a current transformer or a Hall element, or any combination of multiple elements. Any current sampling device 13 must have the characteristics of high detection accuracy and low delay.

[0071] The battery pack 10 further includes a sampling, holding, and amplifying circuit 14 and a filtering circuit 15 connected in series.

[0072] Specifically, the first input terminal and the second input terminal of the sampling, holding and amplifying circuit 14 are respectively connected to the first terminal and the second terminal of the current sampling device 13, and the current signal is collected by the current sampling device 13 and amplified. The input terminal of the filtering circuit 15 is connected to the output terminal of the sampling, holding and amplifying circuit 14, and is used to filter the current signal output by the sampling, holding and amplifying circuit 14.

[0073] The sample, hold and amplify circuit 14 includes a third resistor R3 , a fourth resistor R4 , a fifth resistor R5 , a sixth resistor R6 , a seventh resistor R7 , an eighth resistor R8 , an eighth capacitor C8 , a ninth capacitor C9 and an amplifier 141 .

[0074] A first end of the third resistor R3 serves as a first input end of the sample-hold and amplifier circuit 14 and is connected to a first end of the current sampling device 13 . A first end of the fourth resistor R4 serves as a second input end of the sample-hold and amplifier circuit 14 and is connected to a second end of the current sampling device 13 .

[0075] The second end of the third resistor R3 is connected to the first end of the fifth resistor R5, the second end of the fifth resistor R5 is connected to the positive input terminal of the amplifier 141, the first end of the eighth capacitor C8 is connected to the second end of the fifth resistor R5, the second end of the eighth capacitor C8 receives the first voltage, the first end of the seventh resistor R7 is connected to the second end of the fifth resistor R5, and the second end of the seventh resistor R7 is connected to the second end of the eighth capacitor C8. Optionally, the first voltage may be +1.5V.

[0076] The second end of the fourth resistor R4 is connected to the first end of the sixth resistor R6, the second end of the sixth resistor R6 is connected to the inverting input end of the amplifier 141, the first end of the eighth resistor R8 is connected to the second end of the sixth resistor R6, the second end of the eighth resistor R8 is connected to the output end of the amplifier 141, and the ninth capacitor C9 is connected in series across the eighth resistor R8.

[0077] The third terminal of the amplifier 141 receives a second voltage, and optionally, the second voltage may be +5 V. The fourth terminal of the amplifier 141 is connected to a third ground terminal, and the third ground terminal may specifically be a digital ground DGND (Digital Ground).

[0078] The energy storage system 1 further includes a digital signal processor 60 (DSP). The input end of the digital signal processor 60 is connected to the output end of the filter circuit 15, receives the current signal output by the filter circuit 15, and determines whether the battery pack 10 is well grounded based on the current signal.

[0079] The current signal collected by the current sampling device 13 is the discharge current released by the first capacitor C1. The current signal is amplified and filtered and sent to the digital signal processor 60. The digital signal processor 60 receives the current signal and determines whether the ground wire 50 is well connected at this time.

[0080] When the grounding wire 50 is disconnected or abnormally connected, only the first power line 30 remains connected between the inverter 21 and the battery pack 10. At the moment the first capacitor C1 discharges, the current on the current sampling device 13 is 0. At this time, the digital signal processor 60 determines that the grounding has failed, reports the fault information and issues an alarm.

[0081] In conjunction with Figures 1 and 2, further reference is made to Figure 3, which is a schematic structural diagram of a third embodiment of the energy storage system of the present application. As shown in Figure 3, the energy storage system 1 includes multiple battery packs 10, which are arranged in parallel with a converter assembly 20. The multiple battery packs 10 are stacked in sequence, with the converter assembly 20 positioned at the top layer.

[0082] Optionally, in one embodiment, the energy storage system 1 may include multiple digital signal processors 60, which are respectively arranged in multiple battery packs 10 to connect the sampling, holding and amplification circuits 14 and the filtering circuits 15 of the corresponding battery packs 10, and each digital signal processor 60 is used to perform status detection on the ground wire 50 of the corresponding battery pack 10.

[0083] Optionally, in another embodiment, the energy storage system 1 may be provided with a single digital signal processor 60 , which is connected in parallel to the output ends of the filter circuits 15 of multiple battery packs 10 , and performs status detection on the ground wires 50 of the multiple battery packs 10 respectively.

[0084] Specifically, in response to a grounding abnormality in any one of the plurality of battery packs 10 , the digital signal processor 60 generates an alarm signal and controls the energy storage system 1 to stop.

[0085] In response to the grounding wires 50 of the multiple battery packs 10 being properly connected, the energy storage system 1 is determined to be well grounded and then enters normal operation mode. At this point, the second switching element RLY2 in each battery pack 10 is controlled to close, the third switching element RLY3 in each battery pack 10 is controlled to open, and the first switching element RLY1 in each battery pack 10 performs a soft start function, thereby controlling the inverter 21 connected to each battery pack 10 to start.

[0086] The present application sets a current sampling device 13, and the first power line 30 coupling the battery pack 10 and the converter component 20, the grounding line 50 and the current sampling device 13 form a second current loop, that is, a grounding loop of the energy storage system 1. When the second current loop is turned on, the current sampling device 13 obtains the sampling current in the loop, and the size of the sampling current can be used to quickly determine whether the current battery pack 10 is abnormally grounded.

[0087] The above are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An energy storage system, characterized in that: The energy storage system comprises: A battery pack, the battery pack comprising a power supply component, a switch component, and a current sampling device, the power supply component being coupled to the switch component and the current sampling device respectively; a current conversion component connected to the current sampling device via a first power line, and connected to the switch component via a second power line and a ground line; wherein the current sampling device, the first power line, the current conversion component, and the second power line form a first current loop; and the current sampling device, the first power line, the current conversion component, and the ground line form a second current loop; The switch component is used to control the first current loop and / or the second current loop to be turned on or off; In response to the first current loop being cut off and the second current loop being turned on, the current sampling device obtains a sampling current and determines whether the battery pack is well grounded based on the sampling current; the sampling current is the loop current of the second current loop.

2. The energy storage system according to claim 1, characterized in that The power supply assembly includes: DCDC power supply, used to provide power supply voltage; A transformer, wherein the first end and the second end of the transformer are connected to the first end and the second end of the DCDC power supply respectively; wherein the first end and the second end of the transformer are same-named ends; A power circuit, the third end and the fourth end of the transformer are respectively connected to the power circuit, the switch component is connected in series between the power circuit and the second power line, the switch component is also connected in series between the power circuit and the ground line, and the current sampling device is connected in series between the power circuit and the first power line.

3. The energy storage system according to claim 2, characterized in that: The power supply assembly further includes: a first capacitor, wherein a first end of the first capacitor is connected to the first end of the DCDC power supply, a second end of the first capacitor is connected to the second end of the DCDC power supply, and the second end of the first capacitor is further connected to the second end of the transformer; A first switching element, wherein a first end of the first switching element is connected to a first end of the first capacitor, and a second end of the first switching element is connected to a first end of the transformer.

4. The energy storage system according to claim 2, characterized in that: The switch assembly comprises: a second switch element, wherein a first end of the second switch element is connected to the first end of the ground line, the first end of the second switch element is also connected to the first ground end, and a second end of the second switch element is connected to the second ground end; a third switching element, wherein a first end of the third switching element is connected to the second end of the second switching element, and a second end of the third switching element is connected to the first end of the second power line.

5. The energy storage system according to claim 4, characterized in that: The power circuit includes a second capacitor, a third capacitor, a fourth capacitor and a first resistor; A first end of the second capacitor is connected to the third end of the transformer, a second end of the second capacitor is connected to the fourth end of the transformer, and the second end of the second capacitor is also connected to the second ground end. A first end of the third capacitor is connected to the first end of the second capacitor, and the second end of the third capacitor is connected to the first ground end. A first end of the fourth capacitor is connected to the second end of the third capacitor, and the second end of the fourth capacitor is connected to the second end of the second capacitor. A first end of the current sampling device is connected to the first end of the second capacitor, and a second end of the current sampling device is connected to the first end of the first power line. A first end of the first resistor is connected to the second end of the current sampling device, and a second end of the first resistor is connected to the second end of the third capacitor. The second end of the first resistor is also connected to the first end of the ground line.

6. The energy storage system according to claim 4, characterized in that: The current sampling device is a sampling resistor.

7. The energy storage system according to claim 4, characterized in that: The current conversion component includes a fifth capacitor, a sixth capacitor, a seventh capacitor, a second resistor and an inverter; The first end of the second resistor is connected to the second end of the first power line, the second end of the second resistor is connected to the second end of the ground line, and the second end of the second resistor is also connected to the first ground end. The first end of the fifth capacitor is connected to the first end of the second resistor, and the second end of the fifth capacitor is connected to the second end of the second resistor. The first end of the sixth capacitor is connected to the second end of the fifth capacitor, and the second end of the sixth capacitor is connected to the second ground end. The second end of the sixth capacitor is also connected to the second end of the second power line. The first end of the inverter is connected to the first end of the fifth capacitor, and the second end of the inverter is connected to the second end of the sixth capacitor. The seventh capacitor is connected in parallel to both ends of the inverter.

8. The energy storage system according to claim 4, characterized in that: The first grounding end is an earth ground, and the second grounding end is a power ground.

9. The energy storage system according to claim 1, characterized in that: The battery pack further includes: a sampling, holding, and amplifying circuit, wherein a first input terminal and a second input terminal of the sampling, holding, and amplifying circuit are connected to a first terminal and a second terminal of the current sampling device, respectively, to collect a current signal through the current sampling device and amplify the current signal; A filter circuit, wherein the input end of the filter circuit is connected to the output end of the sampling, holding and amplifying circuit, and is used to filter the current signal output by the sampling, holding and amplifying circuit.

10. The energy storage system according to claim 9, characterized in that: The energy storage system further includes a digital signal processor, wherein an input end of the digital signal processor is connected to an output end of the filter circuit, receives a current signal output by the filter circuit, and determines whether the battery pack is well grounded based on the current signal.

11. The energy storage system according to claim 10, characterized in that: The energy storage system includes a plurality of battery packs, and the plurality of battery packs are arranged in parallel with the converter assembly; In response to a grounding abnormality in any one of the plurality of battery packs, the digital signal processor generates an alarm signal and controls the energy storage system to stop.

12. The energy storage system according to claim 11, characterized in that: The multiple battery packs are stacked in sequence, and the converter assembly is arranged on the top layer.

13. The energy storage system according to claim 11, characterized in that: The energy storage system also includes multiple digital signal processors, which are respectively arranged in the multiple battery packs to connect the sampling, holding and amplification circuits and the filtering circuits of the corresponding battery packs. Each digital signal processor is used to detect the status of the ground wire of the corresponding battery pack.

14. The energy storage system according to claim 11, characterized in that: The energy storage system further includes a single digital signal processor connected in parallel to the output ends of the filter circuits of the multiple battery packs, and the digital signal processor is used to perform status detection on the ground wires of the multiple battery packs respectively.

15. The energy storage system according to claim 13 or 14, characterized in that: The power supply component also includes a first capacitor, and the current signal is the discharge current released by the first capacitor. The current signal is sequentially amplified by the sampling and holding and amplifying circuit and filtered by the filtering circuit and sent to the digital signal processor. The digital signal processor is used to receive the current signal and determine whether the ground wire is well connected.

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