Battery pack, energy storage system and power supply system

Abstract

The embodiment of the utility model provides a battery pack, an energy storage system and a power supply system, relates to the technical field of energy, and is used for effectively solving the problem of abnormal power-off of equipment caused by non-uniform current of output ports of the battery pack. The battery pack comprises a battery cell, a plurality of current limiting circuits and a plurality of port groups, wherein each port group comprises a positive port and a negative port; the positive electrode of the battery cell is connected with the positive electrode port through the plurality of current limiting circuits, or the negative electrode of the battery cell is connected with the negative electrode port through the plurality of current limiting circuits; or the positive electrode and the negative electrode of the battery cell are respectively connected with the positive port and the negative port of the plurality of port groups through the plurality of current limiting circuits.

Description

Technical Field

[0001] This application relates to the field of energy technology, and in particular to a battery pack, energy storage system and power supply system. Background Technology

[0002] Battery packs, as carriers of electrical energy, are widely used in energy storage systems, electrical equipment, and power systems. With the development of energy storage technology, the requirements for the power density and capacity of battery packs are becoming increasingly stringent. High power density or large capacity battery packs also mean that the battery pack has higher input and output power. When the output capacity of the battery pack exceeds the capacity of the trip switch, the trip switch may open, causing abnormal power loss in the equipment.

[0003] To solve the above problems, a higher-capacity disconnect switch can usually be replaced, or the battery pack's output port can be connected to the disconnect switch via multiple cables. However, some electrical equipment or power systems lack the hardware to replace the switch, and there is also a risk of difficulty in securing multiple cables to the battery pack's output port or poor contact. This can lead to uneven current distribution at the battery pack's output port, causing abnormal power-off of the equipment. Utility Model Content

[0004] This application provides a battery pack, energy storage system, and power supply system to effectively solve the problem of uneven current distribution at the output port of the battery pack, which can cause abnormal power-off of the device.

[0005] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, a battery pack is provided, comprising a battery cell, multiple current-limiting circuits, and multiple sets of ports, each set of ports including a positive port and a negative port. The positive terminal of the battery cell is connected to multiple positive ports via the multiple current-limiting circuits, or the negative terminal of the battery cell is connected to multiple negative ports via the multiple current-limiting circuits. For example, the multiple current-limiting circuits are provided between the positive terminal of the battery cell and the multiple positive ports, or between the negative terminal of the battery cell and the multiple negative ports. Alternatively, the positive and negative terminals of the battery cell are connected to the positive and negative ports of the multiple sets of ports via the multiple current-limiting circuits, respectively. For example, the multiple current-limiting circuits are provided between the positive and negative terminals of the battery cell and the multiple sets of ports.

[0007] In the above technical solution, by setting multiple current-limiting circuits between the battery cells and multiple port groups of the battery pack, the multiple current-limiting circuits can limit the output power or input power of the battery pack, and achieve current sharing among the multiple port groups of the battery pack. Thus, even with the advantages of high power density or large capacity in the battery pack, it can still meet the breaking capacity of existing switches in electrical equipment or power systems, effectively preventing abnormal power-off of equipment due to switch disconnection. Compared with existing technologies that upgrade or improve the switch or the connection between the switch and the battery pack, the battery pack structure provided in this application embodiment is simple and has lower replacement costs.

[0008] In addition, these multiple current limiting circuits can be set to the same or different current limiting ratios according to specific application scenarios, which can improve the applicability of the battery pack to a certain extent and meet the power needs of different electrical devices.

[0009] In conjunction with the first aspect, in one embodiment, the positive terminal of the battery cell is connected to a plurality of positive terminals via the plurality of current-limiting circuits, or the negative terminal of the battery cell is connected to a plurality of negative terminals via the plurality of current-limiting circuits. Each current-limiting circuit includes a first switch and a second switch with opposite freewheeling directions. The first switch and the second switch are sequentially connected between the positive terminal and the positive terminal of the battery cell; or, the first switch and the second switch are sequentially connected between the negative terminal and the negative terminal of the battery cell.

[0010] Based on the above scheme, a possible circuit topology for a current limiting circuit is provided. By adjusting the control signals of the two switching transistors, the on / off state of the transmission line from the battery cell to the port group can be flexibly controlled, while achieving bidirectional current control. Furthermore, by adjusting the turn-on and turn-off times of the switching transistors, the output power of the switching transistor port group can be controlled, thus achieving the purpose of current limiting. The circuit topology is simple and has low cost.

[0011] In conjunction with the first aspect, in one embodiment, the positive and negative terminals of the battery cell are connected to the positive and negative ports of the multiple sets of ports respectively through the multiple current-limiting circuits. Each current-limiting circuit includes a third switching transistor and a first capacitor. The first end of the third switching transistor is connected to the positive terminal of the battery cell, the second end of the third switching transistor is connected to the positive port and one end of the first capacitor, and the other end of the first capacitor is connected to the negative port of the same group as the positive port.

[0012] Based on the above scheme, a possible circuit topology for a current limiting circuit is provided. Under the control of a high-frequency control signal, the output power of the switching transistor port group can be controlled by adjusting the turn-on and turn-off times of the switching transistors, and the output power can be stabilized through a capacitor to achieve the purpose of current limiting. The circuit topology is simple and the cost is low.

[0013] In conjunction with the first aspect, in one embodiment, the battery pack further includes a power conversion circuit connected between the battery cell and the plurality of current limiting circuits.

[0014] Based on the above scheme, the power conversion circuit can be a direct current to direct current (DC-DC) circuit to regulate the voltage output or received by the battery cell, so that the power transmitted by the battery pack not only meets the rated power of the switching circuit in the electrical equipment, but also meets the power demand of the electrical equipment.

[0015] In conjunction with the first aspect, in one embodiment, the positive and negative terminals of the battery cell are connected to the positive and negative ports of the multiple sets of ports respectively through the multiple current limiting circuits, each current limiting circuit including a DC-DC converter circuit; the battery cell is connected to a set of the port groups through a DC-DC converter circuit.

[0016] Based on the above scheme, the current limiting circuit may include a DC-DC conversion circuit. In addition to current limiting, the DC-DC conversion circuit can also regulate the output power or input power of the battery cell, such as by boosting or bucking the voltage, so that the power transmitted by the battery pack not only meets the rated power of the switching circuit in the electrical equipment, but also meets the power demand of the electrical equipment.

[0017] In conjunction with the first aspect, in one embodiment, the DC-DC conversion circuit includes a first bridge arm, a second bridge arm, a third bridge arm, a fourth bridge arm, a first inductor, and a second inductor. The first bridge arm and the second bridge arm are connected in parallel, with both ends of the first bridge arm connected to the positive and negative terminals of the battery cell, respectively. The third bridge arm and the fourth bridge arm are connected in parallel, with both ends of the third bridge arm connected to the positive and negative terminals of the set of ports, respectively. The midpoint of the first bridge arm is connected to the midpoint of the third bridge arm through the first inductor, and the midpoint of the second bridge arm is connected to the midpoint of the fourth bridge arm through the second inductor.

[0018] Based on the above scheme, a possible circuit topology for a DC-DC converter is provided. The four bridge arms and two inductors can form a buck-boost DC-DC circuit. While achieving current limiting, the output power or input power of the battery cell can also be regulated, such as boosting or bucking, so that the power transmitted by the battery pack not only meets the rated power of the switching circuit in the electrical equipment, but also meets the power demand of the electrical equipment.

[0019] In conjunction with the first aspect, in one embodiment, the DC-DC conversion circuit includes a first bridge arm, a second bridge arm, a third bridge arm, a fourth bridge arm, a first inductor, and a transformer. The first bridge arm and the second bridge arm are connected in parallel, with both ends of the first bridge arm connected to the positive and negative terminals of the battery cell, respectively. The third bridge arm and the fourth bridge arm are connected in parallel, with both ends of the third bridge arm connected to the positive and negative terminals of the set of ports, respectively. The midpoint of the first bridge arm is connected to the same-name terminal of the primary winding of the transformer through the first inductor, and the opposite-name terminal of the primary winding of the transformer is connected to the midpoint of the second bridge arm. The midpoint of the third bridge arm is connected to the same-name terminal of the secondary winding of the transformer, and the midpoint of the fourth bridge arm is connected to the opposite-name terminal of the secondary winding of the transformer.

[0020] Based on the above scheme, a possible circuit topology for a DC-DC converter is provided. Four bridge arms, one inductor, and one transformer can form a bidirectional active DC-DC circuit. In addition to current limiting, the output power or input power of the battery cell can be regulated, such as by boosting or bucking, so that the power transmitted by the battery pack not only meets the rated power of the switching circuit in the electrical equipment, but also meets the power demand of the electrical equipment.

[0021] In conjunction with the first aspect, in one embodiment, the DC-DC conversion circuit further includes a second capacitor and a third capacitor, wherein the second capacitor is connected in parallel with the first bridge arm and the third capacitor is connected in parallel with the fourth bridge arm.

[0022] Based on the above scheme, the second and third capacitors can stabilize the input and output voltage of the battery cell and improve the anti-interference capability of the battery pack.

[0023] In a second aspect, an energy storage system is provided, comprising a power converter and a battery pack as described in the first aspect or any embodiment thereof, wherein the power converter and the battery pack are connected to multiple sets of ports. The power converter is used to perform power conversion on the direct current output from the battery pack, or the power converter is used to perform power conversion on the direct current input to the battery pack.

[0024] Thirdly, a power supply system is provided, comprising a rectifier, a DC bus, a switching circuit, and a battery pack as described in the first aspect or any embodiment thereof. One end of the rectifier is connected to a power grid, and the other end of the rectifier is connected to the DC bus, which is connected to the battery pack via the switching circuit. The battery pack is used to receive electrical energy supplied by the power grid, or to supply power to a load.

[0025] The descriptions of the second and third aspects in this application can be referenced to the detailed description of the first aspect; and the beneficial effects of the second and third aspects can be referenced to the analysis of the beneficial effects of the first aspect, which will not be repeated here. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a power supply system.

[0027] Figure 2 This is a schematic diagram of another power supply system structure.

[0028] Figure 3 A schematic diagram of a power supply system provided in an embodiment of this application;

[0029] Figure 4 A schematic diagram of the structure of an energy storage system provided in an embodiment of this application;

[0030] Figure 5 This is a schematic diagram of a battery pack provided in an embodiment of this application;

[0031] Figure 6 This is a schematic diagram of another structure of the battery pack provided in an embodiment of this application;

[0032] Figure 7 This is a schematic diagram showing the arrangement of multiple port groups of a battery pack provided in an embodiment of this application;

[0033] Figure 8 This is another schematic diagram of the structure of the battery pack provided in the embodiments of this application;

[0034] Figure 9 This is a schematic diagram of a circuit topology for a battery pack provided in an embodiment of this application;

[0035] Figure 10 A schematic diagram of another circuit topology for a battery pack provided in an embodiment of this application;

[0036] Figure 11 This is a schematic diagram of another circuit topology for a battery pack provided in an embodiment of this application. Detailed Implementation

[0037] The following sections will discuss the fabrication and use of various embodiments in detail. However, it should be understood that many applicable concepts provided in this application can be implemented in a variety of specific environments. The specific embodiments discussed are merely illustrative of specific ways to implement and use this application and technology, and do not limit the scope of this application.

[0038] Unless otherwise defined, all technical terms used herein have the same meaning as commonly known to one of ordinary skill in the art.

[0039] Each circuit or other component may be described or referred to as "for" performing one or more tasks. In this context, "for" is used to imply a structure by indicating that the circuit / component includes a structure (e.g., a circuit system) that performs one or more tasks during operation. Therefore, even when the specified circuit / component is currently inoperable (e.g., not turned on), it can still be referred to as "for performing that task." Circuits / components used with the term "for" include hardware, such as circuits that perform operations.

[0040] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, a and b, a and c, b and c, or a, b, and c, where a, b, and c can be single or multiple. Furthermore, in the embodiments of this application, the words "first," "second," etc., do not limit the quantity or order.

[0041] In this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0042] Before introducing the embodiments of this application, the background technology involved in this application will be introduced first.

[0043] like Figure 1 The diagram illustrates the structure of a power supply system 20, which can be applied to a communication base station. The AC terminal of the power supply system 20 is connected to the power grid 10, and the DC terminal is connected to the load 30. The power supply system 20 mainly includes a rectifier 21, a DC bus 22, a switching circuit 23, and multiple battery packs 24. When the switch in the switching circuit 23 is closed, the path between the DC bus 22 and the multiple battery packs 24 and the load 30 is connected; when the switch in the switching circuit 23 is open, the path between the DC bus 22 and the battery packs 24 and the load 30 is disconnected.

[0044] Reference Figure 1When the communication base station is powered on, the switch in the switching circuit 23 is closed. The rectifier 21 (also called the rectifier circuit) is used to convert the AC power output from the power grid 10 into DC power, and then transmit the DC power to the DC bus 22, which then charges the battery pack 24 and supplies power to the load 30. Alternatively, the battery pack 24 can also transmit the DC power to the DC bus 22 through the switching circuit 23, and then supply power to the load 30 through a switch connected to the load 30.

[0045] The aforementioned switch can be an air switch (also known as an air circuit breaker), a contactor, a semiconductor switch, etc., and this application does not specifically limit it.

[0046] However, with the development of energy storage technology, the requirements for the power density and capacity of the battery pack 24 are becoming increasingly higher. A larger capacity battery pack 24 also means that the battery pack 24 has higher input power and output power. If the input power or output power of the battery pack 24 exceeds the rated power of the switch in the switching circuit 23, the switch in the switching circuit 23 will abnormally disconnect, thus failing to supply power to the load 30 normally, resulting in an abnormal power-off of the communication base station equipment.

[0047] To avoid this situation, such as Figure 2 As shown, the switches in the switching circuit 23 can be upgraded or improved, or the connection between the switches and the battery pack 24 can be modified. For example, a switch with a higher capacity can be replaced, such as replacing a 100A rated current switch with a 150A rated current switch. Another example is using a battery pack 24 with multiple output ports, connecting each output port of the battery pack 24 to its corresponding switch via multiple cables. Yet another example is connecting a single output port of the battery pack 24 to multiple switches via multiple cables.

[0048] However, in the above technical solution, when upgrading and improving the switch in the switching circuit 23, not only is it necessary to spend more money to upgrade the power system 20 of the base station, but some older power systems 20 may also be unable to support the connection of higher-capacity switches. When improving the connection method between the switch and the battery pack 24, there is also a risk of difficulty in locking the cable and the terminal or poor contact, which may cause uneven current output at the port of the battery pack 24, and may still result in abnormal disconnection of the switch in the switching circuit 23, thereby causing abnormal power-off of the communication base station.

[0049] Therefore, this application provides a battery pack 24 that effectively solves the problem of uneven current distribution at the output port of the battery pack 24, which can cause abnormal power-off of the device. The battery pack 24 provided in this application can be applied to a power system 40 (such as...). Figure 3 (as shown) and energy storage system 50 (e.g.) Figure 4 As shown in the figure.

[0050] like Figure 3 As shown, the power system 40 provided in this embodiment includes a rectifier 41, a DC bus 42, a switching circuit 43, and a battery pack 44. One end of the rectifier 41 is connected to the power grid 10, and the other end of the rectifier 41 is connected to the DC bus 42. The DC bus 42 is connected to the battery pack 44 through the switching circuit 43, which is also used to connect a load 30. The battery pack 44 is used to receive electrical energy from the power grid 10, or it is used to supply power to the load 30.

[0051] See Figure 3 The battery pack 44 provided in this embodiment includes battery cells 441 and multiple current limiting circuits 442. The current limiting circuits 442 can limit the output power or input power of the battery cells 441, so that the ports of the battery pack 44 have current limiting capability. In this way, the current limiting threshold of the current limiting circuits 442 can be set according to the existing switching capability in the power system 40, thereby achieving output current sharing at the ports of the battery pack 44 without replacing the switch, effectively avoiding abnormal switch disconnection.

[0052] In one embodiment, the power system 40 may include multiple battery packs 44, which may be connected in series, in parallel, or in a mixed configuration. A mixed configuration refers to a connection method that includes both series and parallel connections. This application does not specifically limit the number of battery packs 44 in the power system 40 or the specific connection method between the multiple battery packs 44. As an example, this application describes a power system 40 including multiple battery packs 44 connected in parallel.

[0053] The energy storage system 50 provided in this application embodiment is as follows: Figure 4 As shown. The energy storage system 50 includes a power converter 51 and a battery pack 44. Multiple sets of ports on the battery pack 44 are connected to the power converter 51. The power converter 51 is used to connect to a load 30 and a DC power supply 60. The power converter 51 is used to convert the DC power output from the DC power supply 60 to power the battery pack 44, or to convert the DC power output from the battery pack 44 to power the load 30.

[0054] The type of the aforementioned energy storage system 50 may include at least one of photovoltaic energy storage system, wind power energy storage system, or power plant energy storage system, and this application embodiment does not specifically limit this.

[0055] The aforementioned energy storage system 50 may include multiple battery packs 44, which may be connected in series, in parallel, or in a mixed configuration. This application embodiment does not specifically limit the number of battery packs 44 in the energy storage system 50, nor the specific connection method between the multiple battery packs 44. As an example, this application embodiment describes an energy storage system 50 comprising multiple battery packs 44 connected in parallel.

[0056] The background technology and application scenarios involved in this application have been introduced above. The battery pack 44 provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0057] Please see Figure 5 and Figure 6 The battery pack 44 provided in this embodiment includes a battery cell 441, multiple current-limiting circuits 442, and multiple port groups BAT. Each port group includes a positive port and a negative port. For distinction, BAT+ can be used to represent the positive port in the port group, and BAT- can be used to represent the negative port in the port group. The positive terminal of the battery cell 441 is connected to the positive port of the multiple port groups through the multiple current-limiting circuits 442, or the negative terminal of the battery cell 441 is connected to the negative port of the multiple port groups through the multiple current-limiting circuits 442. Alternatively, the positive and negative terminals of the battery cell 441 are connected to the positive and negative ports of the multiple port groups through the multiple current-limiting circuits 442, respectively.

[0058] In one embodiment, the battery pack 44 may include multiple battery cells 441, which may be connected in series, in parallel, or in a mixed configuration. Multiple battery cells 441 connected together can achieve the function of a single battery cell 441. This application does not limit the specific number of battery cells 441 included in the battery pack 44, nor the specific connection method between the multiple battery cells 441.

[0059] In one example, the number of current-limiting circuits 442 is the same as the number of port groups, meaning that each port group of the battery pack 44 has current-limiting capability. In another example, the number of current-limiting circuits 442 may be less than the number of port groups, meaning that some port groups of the battery pack 44 have current-limiting capability, while other port groups do not require current limiting.

[0060] By way of example and not limitation, this application describes an embodiment of a battery pack 44 comprising a battery cell 441, two current-limiting circuits 442, and two sets of port groups (e.g., BAT1+ and BAT1-, BAT2+ and BAT2-). For ease of description, [the following is used as an example]. Figure 6 Taking the direction shown as an example, Figure 6 The current limiting circuit 442 located at the top is called the first current limiting circuit, which will... Figure 6The current limiting circuit 442 located at the bottom is called the second current limiting circuit.

[0061] See Figure 6 In (a), the positive terminal of cell 441 is connected to the positive terminal BAT1+ through the first current-limiting circuit, and the positive terminal of cell 441 is also connected to the positive terminal BAT2+ through the second current-limiting circuit. The negative terminal of cell 441 is connected to two negative terminals (e.g., BAT1- and BAT2-). In this way, the current-limiting circuit 442 can be set only between the positive terminal and the positive terminal of cell 441 to form a common negative battery pack 44 structure.

[0062] Alternatively, the negative terminal of cell 441 is connected to the negative terminal port BAT1- through a first current-limiting circuit, and the negative terminal of cell 441 is also connected to the negative terminal port BAT2- through a second current-limiting circuit. The positive terminal of cell 441 is connected to two positive terminals (e.g., BAT1+ and BAT2+). In this way, the current-limiting circuit 442 can be set only between the negative terminal and the negative terminal port of cell 441 to form a common positive battery pack 44 structure.

[0063] See Figure 6 In (b), the positive and negative terminals of cell 441 can be connected to the positive port BAT1+ and the negative port BAT1- through the first current-limiting circuit, and the positive and negative terminals of cell 441 can also be connected to the positive port BAT2+ and the negative port BAT2- through the second current-limiting circuit. In this way, the current-limiting circuit 442 can limit the current to both the positive and negative lines of cell 441.

[0064] The multiple current limiting circuits 442 can be set to the same current limiting ratio or different current limiting ratios according to specific application scenarios, thereby improving the product applicability of the battery pack 44.

[0065] In one example, multiple current-limiting circuits 442 in the battery pack 44 limit the power transmitted by multiple port groups of the battery cell 441 with the same current-limiting ratio. For example, the current-limiting ratio of multiple current-limiting circuits 442 is 80%, that is, the output power of the port group of the battery pack 44 is 80% of the output power of the battery cell 441, so that the multiple port groups of the battery pack 44 can transmit electrical energy to the switching circuit in the electrical device with the same output power.

[0066] In another example, multiple current limiting circuits 442 in the battery pack 44 limit the power transmitted by multiple port groups of the battery cell 441 with different current limiting ratios. For example, in electrical equipment, multiple current limiting circuits 442 can be set to different current limiting ratios according to the different rated power of each switch in the switching circuit, so that multiple port groups of the battery pack 44 can transmit electrical energy to the switching circuit with different output power.

[0067] Continue reading Figure 6 The battery pack 44 provided in this embodiment also includes a battery management circuit 443, which is used to monitor and control the operating state of the battery cell 441. For example, the battery management circuit 443 may include an overcurrent detection circuit, an overtemperature detection circuit, a control circuit, etc., and this embodiment does not specifically limit it.

[0068] In this embodiment, by setting multiple current-limiting circuits 442 between the battery cells 441 and multiple port groups in the battery pack 44, the multiple current-limiting circuits 442 can limit the output power or input power of the battery pack 44 and achieve current sharing among the multiple port groups of the battery pack 44. Thus, even with the advantages of high power density or large capacity, the battery pack 44 can still meet the breaking capacity of existing switches in the electrical equipment or power system 40, avoiding abnormal power-off of the equipment due to switch disconnection. Compared to prior art methods that upgrade or improve the switch or the connection between the switch and the battery pack 44, the battery pack 44 provided in this embodiment has a simple structure and lower replacement cost.

[0069] Figure 7 This illustration shows the arrangement of multiple port groups provided in an embodiment of this application. As an example and not a limitation, this embodiment uses a battery pack 44 comprising two port groups as an example for explanation. The port groups of the battery pack 44 can be located on the same plane of the battery pack 44's housing, such as... Figure 7 As shown in (a) and (b), the port group of battery pack 44 may be located on different planes of the housing of battery pack 44, as shown in Figures 1 and 2. Figure 7 As shown in (c) to (e) in the diagram.

[0070] like Figure 7 As shown in (a), the port groups of the battery pack 44 can be arranged sequentially on one side of the battery pack 44 in the order of positive port BAT1+, negative port BAT1-, positive port BAT2+, and negative port BAT2-. Figure 7 As shown in (b), the port group of the battery pack 44 can also be arranged on one side of the battery pack 44 in the order of positive port BAT1+, positive port BAT2+, negative port BAT1-, and negative port BAT2-. In the two examples above, the port group of the battery pack 44 can also be arranged in the order of negative port BAT1-, negative port BAT2-, positive port BAT1+, and positive port BAT2+, or in the order of negative port BAT1-, positive port BAT1+, negative port BAT2-, and positive port BAT2+.

[0071] like Figure 7As shown in (c), the negative terminals (BAT1- and BAT2-) in the port group of the battery pack 44 are located on one side of the battery pack 44, and the positive terminals (BAT1+ and BAT2+) in the port group of the battery pack 44 are arranged side by side with the negative terminals and are located on different planes of the housing of the battery pack 44. Or, as Figure 7 As shown in (d) and (e), the positive terminals (BAT1+ and BAT2+) and negative terminals (BAT1- and BAT2-) in the port group of the battery pack 44 are arranged alternately and located on different planes of the housing of the battery pack 44.

[0072] In the above embodiment, the port of the battery pack 44 can be connected to the switching circuit 43 by OT terminal crimping. OT terminal crimping refers to a permanent connection method that deforms or alters the geometry of the cylindrical tube on the cable conductor by applying pressure.

[0073] In this embodiment of the application, different port group arrangements can be selected based on different connection methods between the current limiting circuit 442 and the battery cell 441, so as to optimize the wiring of the battery pack 44 and thus avoid problems such as insufficient cable length or messy internal circuit wiring of the battery pack 44 to a certain extent.

[0074] In one embodiment, such as Figure 8 As shown in (a) and (b), the battery pack 44 also includes a power conversion circuit 444 connected between the battery cell 441 and a plurality of current limiting circuits 442.

[0075] For example, the power conversion circuit 444 can be a DC-DC circuit. This DC-DC circuit can convert the DC power output from the battery cell 441 and transmit the converted DC power to the port group of the battery pack 44 through the current limiting circuit 442. The DC-DC circuit can also convert the DC power received by the battery pack 44 and transmit it to the battery cell 441. The above power conversion includes boost processing or buck processing. The DC-DC circuit can regulate the voltage output or received by the battery cell 441 so that the power transmitted by the battery pack 44 not only meets the rated power of the switching circuit 43, but also meets the power demand of the electrical equipment.

[0076] The structure of the battery pack 44 and the arrangement of the port groups have been described above. The following section combines... Figures 9 to 11 This paper describes several circuit topologies of the current limiting circuit 442 in the battery pack 44.

[0077] In one embodiment, the positive terminal of the battery cell 441 is connected to the positive port BAT+ of multiple port groups through multiple current-limiting circuits 442, or the negative terminal of the battery cell 441 is connected to the negative port BAT- of multiple port groups through multiple current-limiting circuits 442. Each current-limiting circuit 442 includes a first switch Q1 and a second switch Q2 with opposite freewheeling directions. The first switch Q1 and the second switch Q2 are sequentially connected between the positive terminal and the positive port of the battery cell 441; or, the first switch Q1 and the second switch Q2 are sequentially connected between the negative terminal and the negative port of the battery cell 441. The opposite freewheeling directions mean that the drain or collector of the first switch Q1 and the drain or collector of the second switch Q2 are connected, or the source or emitter of the first switch Q1 and the source or emitter of the second switch Q2 are connected.

[0078] The first switch Q1 and the second switch Q2 described above, as well as each switch in the following embodiments, may include a metal-oxide-semiconductor field-effect transistor (MOSFET), which may also be simply referred to as a MOS transistor. Each MOS transistor includes a reverse-biased body diode. Alternatively, each switch may include an insulated-gate bipolar transistor (IGBT) and a diode D, with the collector of the IGBT connected to the cathode of the diode D, and the emitter of the IGBT connected to the anode of the diode D. By way of example and not limitation, the embodiments of this application are described using the example of each switch including an IGBT and a diode D.

[0079] For example, such as Figure 9 As shown in (a), by adjusting the control signals of the two switching transistors, the on / off state of the transmission line from cell 441 to the port group can be flexibly controlled, while achieving bidirectional current control. For example, when it is necessary to block current flow, this can be achieved by controlling the simultaneous turn-off of the two IGBTs. The body diodes in the two switching transistors can jointly block reverse current, thereby effectively preventing current flow. As another example, when it is necessary to limit the output or input power of the port group, under the control of the control signal, the duty cycle of the switching transistors is adjusted to control the on and off times of the switching transistors. The longer the off time of the switching transistors, the lower the output power of the port group, relying on the freewheeling effect of the diodes to stabilize the output power.

[0080] In one embodiment, the positive and negative terminals of the battery cell 441 are connected to the positive and negative ports of multiple sets of ports respectively through multiple current-limiting circuits 442. Each current-limiting circuit 442 includes a third switch Q3 and a first capacitor C1. The first end of the third switch Q3 is connected to the positive terminal of the battery cell 441, the second end of the third switch Q3 is connected to the positive port and one end of the first capacitor C1, and the other end of the first capacitor C1 is connected to the negative port of the same group as the positive port.

[0081] For example, such as Figure 9 As shown in (b), the emitter of the third switch Q3 is connected to both the positive port BAT1+ and one end of the first capacitor C1. The collector of the third switch Q3 is connected to the positive terminal of the battery cell 441. Alternatively, when the power conversion circuit 444 is present, the collector of the third switch Q3 is connected to the positive terminal of the battery cell 441 through the power conversion circuit 444. The first capacitor C1 is connected between the positive port BAT1+ and the negative port BAT1-. When it is necessary to limit the output power or input power of the port group, the duty cycle of the switch is adjusted under the action of the high-frequency control signal to control the turn-on and turn-off times of the switch. The longer the turn-off time of the switch, the smaller the output power of the port group, relying on the capacitor to stabilize the output power.

[0082] In the two embodiments described above, the current limiting circuit 442 can achieve the purpose of current limiting through two switching transistors or through one switching transistor and one capacitor. The circuit topology is simple and the cost is low.

[0083] In some embodiments, such as Figure 10 and Figure 11 As shown, the positive and negative terminals of the battery cell 441 are connected to the positive and negative ports of multiple sets of port groups respectively through multiple current-limiting circuits 442. Each current-limiting circuit 442 includes a DC-DC conversion circuit. The battery cell 441 is connected to one set of port groups (e.g., BAT1+ and BAT1-) through a DC-DC conversion circuit. The battery cell 441 is also connected to another set of port groups (e.g., BAT2+ and BAT2-) through another DC-DC conversion circuit.

[0084] In one embodiment, such as Figure 10 As shown, the DC-DC converter circuit includes a first bridge arm, a second bridge arm, a third bridge arm, a fourth bridge arm, a first inductor L1, and a second inductor L2. For example, using... Figure 10 Taking the direction shown by the current limiting circuit 442 located at the top as an example, from left to right, they are the first bridge arm, the second bridge arm, the third bridge arm, and the fourth bridge arm.

[0085] The first bridge arm is connected in parallel with the second bridge arm, and the two ends of the first bridge arm are connected to the positive and negative terminals of cell 441, respectively. The third bridge arm is connected in parallel with the fourth bridge arm, and the two ends of the third bridge arm are connected to the positive terminal BAT1+ and the negative terminal BAT1-, respectively. The midpoint of the first bridge arm is connected to the midpoint of the third bridge arm through the first inductor L1, and the midpoint of the second bridge arm is connected to the midpoint of the fourth bridge arm through the second inductor L2.

[0086] Each of the four bridge arms mentioned above includes two series-connected switching transistors. The first bridge arm, second bridge arm, third bridge arm, fourth bridge arm, first inductor L1, and second inductor L2 can form a buck-boost DC-DC circuit. The buck-boost DC-DC circuit can not only limit current but also regulate the output or input voltage of the battery cell 441. Furthermore, since multiple port groups are each equipped with a current-limiting circuit 442, a battery pack 44 can also supply power to multiple power systems 40 by adjusting different output or input voltages, and can set different output or input voltages based on the different needs of the power systems 40.

[0087] In another embodiment, such as Figure 11 As shown, the DC-DC conversion circuit includes a first bridge arm, a second bridge arm, a third bridge arm, a fourth bridge arm, a first inductor L1, and a transformer T1. For example, using... Figure 11 Taking the direction shown by the current limiting circuit 442 located at the top as an example, from left to right, they are the first bridge arm, the second bridge arm, the third bridge arm, and the fourth bridge arm.

[0088] The first bridge arm is connected in parallel with the second bridge arm, and the two ends of the first bridge arm are connected to the positive and negative terminals of cell 441, respectively. The third bridge arm is connected in parallel with the fourth bridge arm, and the two ends of the third bridge arm are connected to the positive terminal BAT1+ and the negative terminal BAT1-, respectively. The midpoint of the first bridge arm is connected to the same-name terminal of the primary winding of transformer T1 through the first inductor L1, and the opposite-name terminal of the primary winding of transformer T1 is connected to the midpoint of the second bridge arm; the midpoint of the third bridge arm is connected to the same-name terminal of the secondary winding of transformer T1, and the midpoint of the fourth bridge arm is connected to the opposite-name terminal of the secondary winding of transformer T1.

[0089] Each of the four bridge arms mentioned above includes two series-connected switching transistors. The first, second, third, and fourth bridge arms, the first inductor L1, and the transformer T1 can constitute a bidirectional active DC-DC circuit. This bidirectional active DC-DC circuit not only limits current but also regulates the output or input voltage of the battery cell 441. Furthermore, since multiple port groups are each equipped with a current-limiting circuit 442, a battery pack 44 can also supply power to multiple power systems 40 by adjusting different output or input voltages, and can set different output or input voltages based on the different needs of the power systems 40.

[0090] In one embodiment, such as Figure 10 and Figure 11 As shown, the DC-DC conversion circuit also includes a second capacitor C2 and a third capacitor C3. The second capacitor C2 is connected in parallel with the first bridge arm, and the third capacitor C3 is connected in parallel with the fourth bridge arm. The second capacitor C2 is used to stabilize the voltage transmitted between the battery cell 441 and the first bridge arm, and the third capacitor C3 is used to stabilize the voltage transmitted between the fourth bridge arm and the port group, which can further improve the anti-interference capability of the battery pack 44.

[0091] The current limiting circuit 442 described in both of the above embodiments both have the function of power conversion. In one example, the power conversion circuit 444 provided in this application embodiment can be... Figure 10 The example shown is a buck-boost DC-DC circuit. In another example, the power conversion circuit 444 provided in this embodiment is... Figure 11 The bidirectional active DC-DC circuit shown is shown.

[0092] This application embodiment also provides an energy storage system 50, the structure of which is as follows: Figure 4 As shown. It includes a power converter 51 and a battery pack 44, with multiple sets of ports connected to the power converter 51 and the battery pack 44. The circuit topology of the battery pack 44 is as described above. Figures 3 to 6 as well as Figures 8 to 11 The circuit topology of the battery pack 44 shown in any of the attached figures is such that the power converter 51 is used to convert the DC power output from the battery pack 44, or the power converter 51 is used to convert the DC power input to the battery pack 44.

[0093] The above detailed description of the battery pack 44 and the analysis of its beneficial effects can be applied to the energy storage system 50, and will not be repeated here in the embodiments of this application.

[0094] This application embodiment also provides a power supply system 40, the power supply system 40 as follows: Figure 3As shown. It includes a rectifier 41, a DC bus 42, a switching circuit 43, and a battery pack 44. The circuit topology of the battery pack 44 is as described above. Figures 3 to 6 as well as Figures 8 to 11 The circuit topology of the battery pack 44 is shown in any of the attached figures. One end of the rectifier 41 is connected to the power grid 10, and the other end of the rectifier 41 is connected to the DC bus 42, which is connected to the battery pack 44 via a switching circuit 43. The battery pack 44 is used to receive electrical energy from the power grid 10, or, the battery pack 44 is used to supply power to the load 30.

[0095] The above detailed description of the battery pack 44 and the analysis of its beneficial effects can be applied to the power system 40, and will not be repeated here in the embodiments of this application.

[0096] Finally, it should be noted that the above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery pack, characterized by, The battery pack comprises a plurality of groups of port groups, each group of the port groups comprising a positive electrode port and a negative electrode port; The positive electrode of the battery cell is connected to a plurality of the positive electrode ports through a plurality of current limiting circuits, or the negative electrode of the battery cell is connected to a plurality of the negative electrode ports through a plurality of current limiting circuits; Alternatively, the positive electrode and the negative electrode of the battery cell are connected to the positive electrode ports and the negative electrode ports of the plurality of groups of port groups through the plurality of current limiting circuits, respectively.

2. The battery pack of claim 1, wherein, The positive electrode of the battery cell is connected to a plurality of the positive electrode ports through a plurality of current limiting circuits, or the negative electrode of the battery cell is connected to a plurality of the negative electrode ports through a plurality of current limiting circuits, each of the current limiting circuits comprising a first switch tube and a second switch tube with opposite directions of freewheeling; The first switch tube and the second switch tube are connected in sequence between the positive electrode of the battery cell and the positive electrode port; or, The first switch tube and the second switch tube are connected in sequence between the negative electrode of the battery cell and the negative electrode port.

3. The battery pack of claim 1, wherein, The positive electrode and the negative electrode of the battery cell are connected to the positive electrode ports and the negative electrode ports of the plurality of groups of port groups through the plurality of current limiting circuits, respectively, each of the current limiting circuits comprising a third switch tube and a first capacitor; The first end of the third switch tube is connected to the positive electrode of the battery cell, the second end of the third switch tube is connected to the positive electrode port and one end of the first capacitor, and the other end of the first capacitor is connected to the negative electrode port of the same group as the positive electrode port.

4. The battery pack of claim 2 or 3, wherein, The battery pack further comprises a power conversion circuit connected between the battery cell and the plurality of current limiting circuits.

5. The battery pack of claim 1, wherein, The positive electrode and the negative electrode of the battery cell are connected to the positive electrode ports and the negative electrode ports of the plurality of groups of port groups through the plurality of current limiting circuits, respectively, each of the current limiting circuits comprising a direct current-direct current (DC-DC) conversion circuit, and the battery cell is connected to one group of the port groups through one DC-DC conversion circuit.

6. The battery pack of claim 5, wherein, The DC-DC conversion circuit comprises a first bridge arm, a second bridge arm, a third bridge arm, a fourth bridge arm, a first inductor, and a second inductor; The first bridge arm and the second bridge arm are connected in parallel, the bridge arm two ends of the first bridge arm are connected to the positive electrode and the negative electrode of the battery cell, respectively, the third bridge arm and the fourth bridge arm are connected in parallel, and the bridge arm two ends of the third bridge arm are connected to the positive electrode port and the negative electrode port of the one group of port groups, respectively; The bridge arm midpoint of the first bridge arm is connected to the bridge arm midpoint of the third bridge arm through the first inductor, and the bridge arm midpoint of the second bridge arm is connected to the bridge arm midpoint of the fourth bridge arm through the second inductor.

7. The battery pack of claim 5, wherein, The DC-DC conversion circuit comprises a first bridge arm, a second bridge arm, a third bridge arm, a fourth bridge arm, a first inductor, and a transformer; The first bridge arm and the second bridge arm are connected in parallel, the bridge arm two ends of the first bridge arm are connected to the positive electrode and the negative electrode of the battery cell, respectively, the third bridge arm and the fourth bridge arm are connected in parallel, and the bridge arm two ends of the third bridge arm are connected to the positive electrode port and the negative electrode port of the one group of port groups, respectively; The bridge arm midpoint of the first bridge arm is connected with the same name end of the primary winding of the transformer through the first inductor, the different name end of the primary winding of the transformer is connected with the bridge arm midpoint of the second bridge arm, the bridge arm midpoint of the third bridge arm is connected with the same name end of the secondary winding of the transformer, and the bridge arm midpoint of the fourth bridge arm is connected with the different name end of the secondary winding of the transformer.

8. The battery pack of claim 6 or 7, wherein, The DC-DC conversion circuit further comprises a second capacitor and a third capacitor, wherein: The second capacitor is connected in parallel with the first bridge arm, and the third capacitor is connected in parallel with the fourth bridge arm.

9. An energy storage system characterized by, The energy storage system comprises a power converter and the battery pack of any one of claims 1-8, and the power converter and the multiple groups of ports of the battery pack are connected; The power converter is used for power conversion of the direct current output by the battery pack, or the power converter is used for power conversion of the direct current input to the battery pack.

10. A power supply system characterized by comprising: The power supply system comprises a rectifier, a direct current bus, a switching circuit and the battery pack of any one of claims 1-8, one end of the rectifier is used for connecting a power grid, the other end of the rectifier is connected with the direct current bus, and the direct current bus is connected with the battery pack through the switching circuit; The battery pack is used for receiving power provided by the power grid, or the battery pack is used for supplying power to a load.

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