Electrical apparatus

Abstract

The application provides an electrical device, and belongs to the technical field of power electronics. The drive device provided by the application adopts an energy storage capacitor to supply power for a driving circuit. Compared with a magnetic coupling device such as an isolation transformer, the energy storage capacitor has a smaller volume, and can ensure that the drive device of the circuit breaker has a smaller board area. Moreover, the drive device of the circuit breaker can charge the energy storage capacitor only when a DC power supply abnormality is detected, and the energy storage capacitor can in turn supply power for the driving circuit, so that the drive device can also ensure that the power consumption is low, the performance of the DC power supply (such as a battery pack) is not affected, and the charging and discharging efficiency of the energy storage system is not affected.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to an electrical device. Background Technology

[0002] An energy storage system typically includes a battery cluster, a power conversion system (PCS), and a cluster control box. The battery cluster comprises multiple battery packs connected in series. The PCS is used to charge and discharge the battery packs within the cluster. The cluster control box connects the battery cluster and the PCS, controlling the connection and disconnection between them to achieve charge and discharge control.

[0003] To ensure the safety of the energy storage system during operation, each battery pack is equipped with a circuit breaker (such as an active trip fuse). In the event of abnormalities such as overvoltage, overcurrent, or overtemperature in the battery pack, this circuit breaker can disconnect the power circuit of the battery pack to achieve fault protection. The drive circuit of the circuit breaker is generally powered by an isolation transformer, which utilizes the AC component of the power current from the battery pack to power the drive circuit.

[0004] However, isolation transformers are relatively large and occupy a significant amount of board space. Furthermore, the isolation transformer continuously supplies power to the drive circuit, resulting in high power consumption in the drive circuit. Utility Model Content

[0005] This application provides an electrical device that solves the technical problem that using an isolation transformer to power the drive circuit of a circuit breaker results in a large board area and high power consumption for the drive device of the circuit breaker.

[0006] In a first aspect, an electrical device is provided, comprising: a charging circuit, an anomaly detection circuit, an energy storage capacitor, a drive circuit, and a circuit breaker. One end of the charging circuit is connected to a DC power supply, and the other end is connected to the energy storage capacitor. The charging circuit charges the energy storage capacitor when the anomaly detection circuit detects an anomaly in the DC power supply. The energy storage capacitor is connected to the drive circuit and supplies power to the drive circuit. The circuit breaker is connected in series between the positive and negative terminals of the DC power supply, and the drive circuit drives the circuit breaker to disconnect when the DC power supply is abnormal. The DC power supply anomaly includes at least one of the following: overvoltage, overcurrent, overtemperature, liquid leakage, and abnormal concentration of combustible gas.

[0007] The electrical equipment provided in this application uses an energy storage capacitor to power the drive circuit. Compared to magnetically coupled devices such as isolation transformers, this energy storage capacitor is smaller in size, ensuring a smaller footprint. Furthermore, the electrical equipment can only charge the energy storage capacitor when an abnormality in the DC power supply is detected, allowing the energy storage capacitor to then power the drive circuit. This also ensures low power consumption in the drive circuit, avoiding impact on the performance of the DC power supply (such as a battery pack), and consequently, avoiding impact on the charging and discharging efficiency of the energy storage system.

[0008] In one possible implementation, the drive circuit includes a first switch connected in series between the energy storage capacitor and the circuit breaker. This first switch is configured to disconnect when the DC power supply is normal and to connect when the DC power supply is abnormal. This ensures that the energy storage capacitor can only supply power to the circuit breaker when the DC power supply is abnormal, thereby driving the circuit breaker to disconnect.

[0009] In one possible implementation, the drive circuit further includes a second switch, with the first and second switches connected in series between the energy storage capacitor and the circuit breaker. The second switch is used to disconnect when the voltage of the energy storage capacitor is less than or equal to a first voltage threshold, and to turn on when the voltage of the energy storage capacitor is greater than the first voltage threshold.

[0010] The first voltage threshold can be greater than or equal to the minimum voltage required for the circuit breaker to reliably disconnect. The second switch only turns on when the voltage of the energy storage capacitor is greater than the first voltage threshold, which ensures that the energy storage capacitor reliably supplies power to the circuit breaker, and thus ensures that the drive circuit can reliably drive the circuit breaker to disconnect when the DC power supply is abnormal.

[0011] In one possible implementation, the charging circuit includes a first charging branch and a second charging branch. One end of the first charging branch is connected to a DC power supply, and the other end is connected to an energy storage capacitor. The first charging branch charges the energy storage capacitor when the voltage of the DC power supply exceeds a second voltage threshold. The first end of the second charging branch is connected to the DC power supply, the second end is connected to the energy storage capacitor, and the third end is connected to an anomaly detection circuit. The second charging branch charges the energy storage capacitor when the anomaly detection circuit detects an anomaly in the DC power supply. The second voltage threshold is greater than the rated voltage of the DC power supply and less than the overvoltage threshold of the DC power supply.

[0012] By setting the first charging branch to charge the energy storage capacitor in advance when the DC power supply voltage is high but has not yet reached the overvoltage threshold, it can be ensured that when the DC power supply is abnormal (such as when the voltage reaches the overvoltage threshold), the voltage of the energy storage capacitor has reached the aforementioned first voltage threshold, thereby ensuring that the drive circuit can quickly and reliably drive the circuit breaker to disconnect.

[0013] In one possible implementation, the first charging branch includes a Zener diode. The negative terminal of the Zener diode serves as one end of the first charging branch, connected to the positive terminal of the DC power supply, while the positive terminal of the Zener diode serves as the other end of the first charging branch, connected to an energy storage capacitor. Using a Zener diode as the first charging branch ensures a simple structure and low cost.

[0014] In one possible implementation, the second charging branch includes a switching transistor. The first terminal of the switching transistor serves as the first terminal of the second charging branch and is connected to a DC power supply, the second terminal of the switching transistor serves as the second terminal of the second charging branch and is connected to an energy storage capacitor, and the control terminal of the switching transistor serves as the third terminal of the second charging branch and is connected to an abnormality detection circuit.

[0015] Using a switching transistor to form the second charging branch ensures that the structure of the second charging branch is relatively simple and the cost is low, while ensuring that the fault detection circuit can effectively control the on / off state of the second charging branch.

[0016] In one possible implementation, the anomaly detection circuit includes multiple voltage detection circuits, and the anomaly detection circuit detects a DC power supply anomaly by all multiple voltage detection circuits detecting DC power supply overvoltage.

[0017] DC power supply overvoltage refers to the DC power supply voltage reaching an overvoltage threshold that is greater than the charging cutoff voltage of the DC power supply. For example, the overvoltage threshold could be the critical opening voltage of the DC power supply. By setting up multiple voltage detection circuits, redundant detection of the DC power supply voltage can be achieved, thereby effectively improving the accuracy and reliability of anomaly detection and thus effectively reducing the probability of circuit breaker malfunction.

[0018] In one possible implementation, the anomaly detection circuit includes multiple current detection circuits, multiple temperature detection circuits, multiple leakage detection circuits, and multiple gas detection circuits. Accordingly, the anomaly detection circuit detects a DC power supply anomaly in at least one of the following ways: multiple current detection circuits detect DC power supply overcurrent; multiple temperature detection circuits detect DC power supply overtemperature; multiple leakage detection circuits detect DC power supply leakage; and multiple gas detection circuits detect an abnormal concentration of combustible gas within the DC power supply.

[0019] By setting up multiple current detection circuits, multiple temperature detection circuits, multiple gas detection circuits, and multiple leakage detection circuits, redundant detection of current, temperature, combustible gas concentration, and leakage status of DC power supply can be achieved, thereby effectively improving the accuracy and reliability of anomaly detection and thus effectively reducing the probability of circuit breaker malfunction.

[0020] In one possible implementation, the aforementioned electrical device is a battery pack, which further includes multiple battery cells. Furthermore, the aforementioned DC power supply also comprises multiple battery cells. Therefore, the solution provided in this application can achieve autonomous detection and reliable protection against abnormal states of the battery pack.

[0021] In one possible implementation, the aforementioned electrical device is a cluster control box, which further includes a cluster switch for connecting the battery cluster and the power converter. Furthermore, the aforementioned DC power supply is the battery cluster. Therefore, the solution provided in this application can achieve autonomous detection and reliable protection of abnormal states of the battery cluster.

[0022] In one possible implementation, the aforementioned electrical device is a power converter (e.g., an energy storage converter), which further includes a power conversion circuit for converting DC power from a DC power source into AC power. The DC power source is a battery pack or battery cluster. Furthermore, in this implementation, a circuit breaker is connected between the positive and negative terminals of the DC terminal of the power conversion circuit. Therefore, the solution provided in this application enables autonomous detection and reliable protection against abnormal states at the DC terminal of the power conversion circuit.

[0023] Secondly, an energy storage system is provided, comprising a battery cluster and a cluster control box. The battery cluster includes multiple battery packs connected in series. The battery packs in the energy storage system are those provided in the above-described aspect, and / or, the cluster control box in the energy storage system is a cluster control box as provided in the above-described aspect.

[0024] In one possible implementation, the energy storage system further includes a power converter as described above, with the battery cluster connected to the DC terminal of the power converter via a cluster control box. The AC terminal of the power converter is used to connect to the power grid or a load. The power converter is used to convert the DC power from the battery cluster into AC power for output.

[0025] In summary, this application provides an electrical device. This device uses an energy storage capacitor to power the drive circuit. Compared to magnetically coupled devices such as isolation transformers, the energy storage capacitor is smaller in size, ensuring a smaller footprint for the drive unit of the electrical device. Furthermore, the device only charges the energy storage capacitor when an abnormality in the DC power supply is detected, allowing the capacitor to then power the drive circuit. This ensures low power consumption in the drive circuit, avoiding impact on the performance of the DC power supply (such as a battery pack or battery cluster), and consequently, avoiding affecting the charging and discharging efficiency of the energy storage system. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this application; Figure 2This is a schematic diagram of the structure of an electrical device provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a circuit breaker drive device provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a battery pack provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of a cluster control box provided in an embodiment of this application; Figure 6 This is a schematic diagram illustrating the working principle of a circuit breaker drive device provided in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of a power converter provided in an embodiment of this application; Figure 8 This is a schematic diagram showing the installation location of a circuit breaker according to an embodiment of this application; Figure 9 This is a schematic diagram of a battery cluster structure provided in an embodiment of this application. Detailed Implementation

[0027] The electrical equipment provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings. First, the key terms involved in the embodiments of this application will be introduced: A circuit breaker is a device used to actively disconnect a power circuit; it is also called an active disconnecting device. A circuit breaker mainly consists of components such as a fuse, actuator, detection unit, and disconnecting mechanism. When applied to battery packs, it can disconnect the power circuit of the battery pack in abnormal situations such as overvoltage, overcurrent, overtemperature, and leakage. Circuit breakers are also called active disconnecting fuses, hibiscus, explosive fuses, or pyrotechnic switches.

[0028] Overcharge certification refers to the process where, after the battery pack undergoes initial charging, it is charged at a constant current (P / U) to a preset standard without catching fire or exploding. The preset standard may include, for example, any individual battery cell reaching 1.5 times its charging cutoff voltage, or a charging time of 1 hour.

[0029] Cluster control box (RCM), also known as a cluster control module, is a control device in an energy storage system that manages the charging and discharging scheduling and protection of multiple battery packs within a battery cluster. A battery cluster comprises multiple battery packs connected in series and / or parallel.

[0030] Currently, overcharge certification for the entire battery pack is mainly ensured through the design of the individual battery cells. However, due to significant differences in the overcharge resistance of battery cells from different manufacturers, and even large fluctuations in the consistency of battery cells from the same manufacturer, relying solely on the performance of a single battery cell to directly withstand 1.5 times the charging cutoff voltage poses a risk of cell fire or even explosion.

[0031] In scenarios involving battery pack overcharging, insulation failure, or leakage, a circuit breaker is typically included in the battery pack to ensure safety during application. This circuit breaker can be, for example, an active fuse. An active fuse is an intelligent overcurrent protection device that combines the "physical melting" characteristic of a traditional fuse with the "controllable" characteristic of an electronic switch. Unlike the passive melting principle of ordinary fuses, active fuses contain high-energy chemical substances. When signals such as voltage / current exceed a certain threshold, the control circuit triggers ignition, instantly generating high-pressure gas or an impact force to break or rupture the conductor, thus achieving millisecond-level physical isolation.

[0032] In some embodiments, the drive circuit for actively tripping fuses is primarily powered by an isolation transformer. This isolation transformer utilizes the AC component of the battery pack's power current to power the drive circuit. However, this isolation transformer is a magnetically coupled device, resulting in a large size and footprint. Furthermore, since the drive circuit is powered via magnetic coupling, the power supply quality is affected by the amplitude of the AC component of the battery pack's power current. When the battery pack's power current is low and the AC component is excessively high, the isolation transformer continuously outputs significant power to the drive circuit, leading to high power consumption. Conversely, when the battery pack's power current is high and the AC component is low, the isolation transformer outputs less energy to the drive circuit, resulting in poor power supply quality and the inability to reliably trip the circuit.

[0033] Figure 1 This is a schematic diagram of the structure of an energy storage system provided in an embodiment of this application. Figure 1 As shown, the energy storage system may include a battery cluster, a cluster control box, and a power conversion system (PCS). The battery cluster comprises multiple battery packs connected in series. The DC terminal of the PCS is connected to the battery cluster via the cluster control box, while the AC terminal is used to connect to the power grid or a load. The PCS can convert the direct current (DC) output from each battery pack in the battery cluster into alternating current (AC) and output it to the power grid or load. It can also convert the AC power from the power grid into DC and output it to the battery cluster, thereby charging the battery packs within the cluster. In other words, the PCS can achieve bidirectional power conversion between DC and AC. (Continue to refer to...) Figure 1The cluster control box mainly includes a cluster switch and a cluster controller. The cluster switch is connected between the battery cluster and the PCS, and the cluster controller (also called the cluster control board) is used to control the on / off state of the cluster switch, thereby controlling the on / off state between the battery cluster and the PCS.

[0034] The above Figure 1 The structure of the energy storage system shown is merely illustrative; its structure may vary depending on the application scenario. For example, the energy storage system may include multiple battery clusters, which can be connected in parallel to the DC terminal of the same PCS via different cluster control boxes. Alternatively, the multiple battery clusters can be connected to different PCS via different cluster control boxes.

[0035] To ensure the safety of energy storage system operation, such as Figure 1 As shown, each battery pack is equipped with a circuit breaker, which is connected in series with multiple battery cells in the battery pack. This circuit breaker can be disconnected under the drive of a circuit breaker drive device, thereby breaking the power circuit of the battery pack.

[0036] This application provides an electrical device, such as... Figure 2 As shown, the electrical device includes a circuit breaker 20 and a circuit breaker drive device 10 for driving the circuit breaker 20. The circuit breaker drive device 10 includes a charging circuit 11, an anomaly detection circuit 12, an energy storage capacitor C0, and a drive circuit 13. One end of the charging circuit 11 is connected to a DC power source (e.g., a battery pack), and the other end of the charging circuit 11 is connected to the energy storage capacitor C0. The charging circuit 11 charges the energy storage capacitor C0 when the anomaly detection circuit 12 detects an anomaly in the DC power supply. The energy storage capacitor C0 is connected to the drive circuit 13 and supplies power to the drive circuit 13.

[0037] Continue to refer to Figure 2 The circuit breaker 20 is connected in series between the positive (+) and negative (-) terminals of the DC power supply. The drive circuit 13, in the event of a DC power supply failure, uses the energy provided by the energy storage capacitor C0 to drive the circuit breaker 20 to open, thereby disconnecting the power circuit of the DC power supply. That is, the energy storage capacitor C0 is the energy input unit of the drive circuit 13, and the fault detection circuit 12 is the trigger signal input unit of the drive circuit 13. The drive circuit 13 can drive the circuit breaker 20 to open when both input units have input.

[0038] The DC power supply abnormality includes at least one of the following: overvoltage, overcurrent, overtemperature, leakage, and abnormal flammable gas concentration. For example, if the electrical equipment is a battery pack, the DC power supply can be the battery cells in the battery pack, and the DC power supply abnormality can include at least one of overvoltage, overcurrent, overtemperature, leakage, and abnormal flammable gas concentration. Alternatively, if the electrical equipment is a cluster control box, the DC power supply can be the battery cluster, and the DC power supply abnormality can include overvoltage and / or overcurrent.

[0039] In the electrical equipment provided in this application embodiment, the circuit breaker drive device uses an energy storage capacitor to power the drive circuit. Compared to magnetic coupling devices such as isolation transformers, the energy storage capacitor is smaller in size, ensuring a smaller footprint for the circuit breaker drive device. Furthermore, by drawing power from the DC power supply through a charging circuit to charge the energy storage capacitor, and then using the energy storage capacitor to power the drive circuit, the power supply quality of the drive circuit is ensured to be unaffected by the amplitude of the AC component of the DC power supply's power current. This ensures high power supply stability for the drive circuit, thereby ensuring high reliability when the drive circuit trips the circuit breaker. Moreover, since the charging circuit of this drive device only charges the energy storage capacitor when an abnormality in the DC power supply is detected, allowing the energy storage capacitor to then power the drive circuit, the power consumption of the drive device is also kept low. This avoids affecting the performance of the DC power supply, extends the standby time of the DC power supply, and improves the charging and discharging efficiency of the energy storage system.

[0040] In one possible implementation, such as Figure 3 As shown, the drive circuit 13 in the circuit breaker drive device provided in this embodiment includes a first switch K1, which is connected in series between the energy storage capacitor C0 and the circuit breaker 20. The first switch K1 is used to open when the DC power supply is normal and to close when the DC power supply is abnormal. Thus, it can be ensured that the energy storage capacitor C0 can supply power to the circuit breaker 20 only when the DC power supply is abnormal, thereby driving the circuit breaker 20 to open.

[0041] For example, the first switch K1 has a first terminal, a second terminal, and a control terminal. The first terminal is connected to the energy storage capacitor C0, the second terminal is connected to the circuit breaker 20, and the control terminal is connected to the fault detection circuit 12. The first and second terminals of the first switch K1 are in an open state by default. When the fault detection circuit 12 detects a DC power supply fault, it outputs a trigger signal to the first switch K1 to control the first and second terminals of the first switch K1 to conduct. This ensures that when the DC power supply is faulty, the energy storage capacitor C0 can supply power to the circuit breaker 20 through the conducting first switch K1, thereby driving the circuit breaker 20 to turn off.

[0042] In this embodiment, to improve reliability, such as Figure 3 As shown, the drive circuit 13 may include two first switches K1 connected in series. By setting two first switches K1 connected in series, it can be ensured that even if a short circuit fault occurs in either first switch K1, the connection between the energy storage capacitor C0 and the circuit breaker 20 can still be controlled by the other first switch K1.

[0043] In one possible implementation, continue to refer to Figure 3The drive circuit 13 in the circuit breaker drive device provided in this application embodiment further includes a second switch K2. The second switch K2 and the first switch K1 are connected in series between the energy storage capacitor C0 and the circuit breaker 20. The second switch K2 is used to disconnect when the voltage of the energy storage capacitor C0 is less than or equal to a first voltage threshold, and to conduct when the voltage of the energy storage capacitor C0 is greater than the first voltage threshold.

[0044] The first voltage threshold is greater than or equal to the minimum voltage required to drive the circuit breaker 20 to disconnect, that is, greater than or equal to the threshold voltage for reliable operation of the circuit breaker 20. For example, the first voltage threshold may be 8 volts (V).

[0045] In this embodiment, when the DC power supply is abnormal, but the voltage of the energy storage capacitor C0 has not yet reached the first voltage threshold, the first switch K1 is turned on and the second switch K2 is turned off. At this time, the drive circuit 13 can ensure that the path between the energy storage capacitor C0 and the circuit breaker 20 is broken, that is, the energy storage capacitor C0 cannot supply power to the circuit breaker 20, and the circuit breaker 20 will not operate. Thus, it can avoid the energy storage capacitor C0 directly supplying power to the circuit breaker 20 when the voltage is low, causing the circuit breaker 20 to operate but fail to reliably disconnect. In addition, since the energy storage capacitor C0 charges quickly, it can ensure that when the DC power supply is abnormal, the voltage of the energy storage capacitor C0 can quickly reach the first voltage threshold, and the drive circuit 13 can then drive the circuit breaker 20 to disconnect in a timely manner based on the electrical energy provided by the energy storage capacitor C0.

[0046] Based on the above analysis, it can be seen that the second switch K2 is turned on only when the voltage of the energy storage capacitor C0 is greater than the first voltage threshold, which can ensure that the energy storage capacitor C0 reliably supplies power to the circuit breaker 20, thereby ensuring that the drive device can reliably drive the circuit breaker 20 to disconnect when the DC power supply is abnormal.

[0047] For example, the second switch K1 has a first terminal, a second terminal, and a control terminal, and the drive circuit 13 further includes a capacitor voltage detection circuit. The first and second terminals of the second switch K2 are connected in series with the first switch K1, and the control terminal of the second switch K2 is connected to the capacitor voltage detection circuit. The first and second terminals of the second switch K1 are in an off state by default. The capacitor voltage detection circuit detects the voltage of the energy storage capacitor C0 and, when the detected voltage of the energy storage capacitor C0 is greater than a first voltage threshold, outputs a trigger signal to the second switch K2 to control the first and second terminals of the second switch K2 to conduct.

[0048] In this embodiment, both the first switch K1 and the second switch K2 can be switching transistors. Switching transistors can be, for example, metal. Metal oxide semiconductor field effect transistors (MOSFETs) or insulated gate bipolar transistors (IGBTs) are examples of such transistors. Furthermore, the drive circuit 13 also includes a drive unit for the switching transistor, and the energy storage capacitor C0 is used to power the drive unit for this switching transistor.

[0049] In one possible implementation, continue to refer to Figure 3 The charging circuit 11 includes a first charging branch 111 and a second charging branch 112. One end of the first charging branch 111 is connected to a DC power supply, and the other end is connected to an energy storage capacitor C0. The first charging branch 111 charges the energy storage capacitor C0 when the voltage of the DC power supply exceeds a second voltage threshold. The first end of the second charging branch 112 is connected to a DC power supply, the second end is connected to the energy storage capacitor C0, and the third end is connected to an anomaly detection circuit 12. The second charging branch 112 charges the energy storage capacitor C0 when the anomaly detection circuit 12 detects an anomaly in the DC power supply.

[0050] The second voltage threshold is greater than the rated voltage of the DC power supply and less than the overvoltage threshold of the DC power supply. For example, the second voltage threshold may be greater than or equal to the nominal voltage of the DC power supply; for instance, the second voltage threshold may be the charging cutoff voltage of the DC power supply.

[0051] By setting the first charging branch 111 to charge the energy storage capacitor C0 in advance when the voltage of the DC power supply is high but has not yet reached the overvoltage threshold, it can be ensured that when the DC power supply is abnormal (such as when the voltage reaches the overvoltage threshold), the voltage of the energy storage capacitor C0 has reached the aforementioned first voltage threshold, thereby ensuring that the circuit breaker 20 is driven to disconnect quickly and reliably.

[0052] In one possible implementation, such as Figure 3 As shown, the first charging branch 111 includes a Zener diode D0. The negative terminal of the Zener diode D0 serves as one end of the first charging branch 111 and is connected to the positive terminal of the DC power supply. The positive terminal of the Zener diode D0 serves as the other end of the first charging branch 111 and is connected to the energy storage capacitor C0.

[0053] In this embodiment, the first charging branch 111 may include one or more Zener diodes D0 connected in series. Furthermore, the Zener voltage of at least one Zener diode D0 in the first charging branch 111 is the aforementioned second voltage threshold. Accordingly, when the DC power supply voltage is less than or equal to the second voltage threshold, at least one Zener diode D0 is in the off state, and the DC power supply cannot charge the energy storage capacitor C0. When the DC power supply voltage is greater than the second voltage threshold, at least one Zener diode D0 breaks down in reverse, and the DC power supply begins to charge the energy storage capacitor C0. Using a Zener diode D0 as the first charging branch 111 ensures a simple structure and low cost for the first charging branch 111.

[0054] In this embodiment of the application, the first charging branch 111 may include other components in addition to the Zener diode D0, such as a resistor connected in series with the Zener diode D0.

[0055] In another possible implementation, such as Figure 4 As shown, the first charging branch 111 may include a voltage detection circuit 1110 and a third switch K3. The first terminal of the third switch K3 serves as one end of the first charging branch 111 and is connected to the positive terminal of the DC power supply. The second terminal of the third switch K3 serves as the other end of the first charging branch 111 and is connected to the energy storage capacitor C0. The control terminal of the third switch K3 is connected to the voltage detection circuit 1110. The voltage detection circuit 1110 detects the voltage of the DC power supply and controls the third switch K3 to open when the voltage of the DC power supply is less than or equal to a second voltage threshold, and controls the third switch K3 to open when the voltage of the DC power supply is greater than the second voltage threshold.

[0056] For scenarios where the DC power supply is a battery pack, such as Figure 4 As shown, the battery pack also includes a battery management unit (BMU). The BMU can also control the on / off state of the third switch K3. For example, the BMU can also control the third switch K3 to open when the DC power supply voltage is less than or equal to the second voltage threshold, and control the third switch K3 to open when the DC power supply voltage is greater than the second voltage threshold.

[0057] In one possible implementation, such as Figure 3 As shown, the second charging branch includes a switching transistor M0. The first terminal of the switching transistor M0 serves as the first terminal of the second charging branch 112 and is used to connect to a DC power supply. The second terminal of the switching transistor M0 serves as the second terminal of the second charging branch 112 and is connected to an energy storage capacitor C0. The control terminal of the switching transistor M0 serves as the third terminal of the second charging branch 112 and is connected to an abnormality detection circuit 12.

[0058] In this circuit, the switching transistor M0 can be a MOSFET or an IGBT, etc. After the anomaly detection circuit 12 detects an anomaly in the DC power supply, it provides a conduction signal to the control electrode of the switching transistor M0 to control the switching transistor M0 to conduct, thereby enabling the DC power supply to charge the energy storage capacitor C0. By using the switching transistor M0 to form the second charging branch 112, the structure of the second charging branch 112 is relatively simple and the cost is low, while ensuring that the anomaly detection circuit 12 can effectively control the on / off state of the second charging branch 112.

[0059] In addition to the switching transistor M0, the second charging branch 112 may also include other components, such as the driving unit of the switching transistor M0, like an isolation optocoupler.

[0060] In this application embodiment, for a scenario where the electrical equipment is a cluster control box and the DC power supply is a battery cluster, the DC power supply abnormality may include at least one of overvoltage and overcurrent. Accordingly, as Figure 5 As shown, the anomaly detection circuit 12 may include a voltage detection circuit 121 and a current detection circuit 122. In scenarios where the electrical equipment is a battery pack and the DC power supply consists of multiple cells within the battery pack, DC power supply anomalies may include at least one of the following: overvoltage, overcurrent, overtemperature, leakage, and abnormal flammable gas concentration. Accordingly, as... Figure 4 As shown, the anomaly detection circuit 12 may include a voltage detection circuit 121, a current detection circuit 122, a temperature detection circuit 123, a gas detection circuit 124, and a leakage detection circuit 125. Furthermore, the BMU in the battery pack can also acquire the detection results of the anomaly detection circuit 12.

[0061] The voltage detection circuit 121 can be used to detect the voltage of the DC power supply, and the current detection circuits 122 are both used to detect the current of the DC power supply. The temperature detection circuit 123 can be a temperature sensor, which is used to detect the temperature of the battery pack. The gas detection circuit 124 can be a gas sensor, which is used to detect the concentration of combustible gas inside the battery pack. The leakage detection circuit 125 is used to detect whether the battery pack is leaking.

[0062] In one possible implementation, the anomaly detection circuit 12 includes a plurality of voltage detection circuits 121. For example, Figure 3 Two voltage detection circuits 121 are schematically shown. Accordingly, the anomaly detection circuit 12 detects DC power supply anomalies including: multiple voltage detection circuits 121 all detect DC power supply overvoltage.

[0063] DC power supply overvoltage refers to the DC power supply voltage reaching an overvoltage threshold, which is greater than or equal to the charging cutoff voltage of the DC power supply. For example, if the DC power supply is a battery pack, the overvoltage threshold can be the critical opening voltage of the battery pack. By setting multiple voltage detection circuits 121, redundant detection of the DC power supply voltage can be achieved, thereby effectively improving the accuracy and reliability of anomaly detection, and thus effectively reducing the probability of malfunction of the circuit breaker 20.

[0064] In one possible implementation, the anomaly detection circuit 12 includes multiple current detection circuits 122, multiple temperature detection circuits 123, multiple gas detection circuits 124, and / or multiple leakage detection circuits 125. For example, Figure 3 The diagram schematically illustrates two current detection circuits 122 and two temperature detection circuits 123. Accordingly, the anomaly detection circuit 12 detecting a DC power supply anomaly may include at least one of the following: multiple current detection circuits 122 all detecting DC power supply overcurrent, multiple temperature detection circuits 123 all detecting DC power supply overtemperature, multiple gas detection circuits 124 all detecting abnormal concentration of combustible gas in the DC power supply, and multiple leakage detection circuits 125 all detecting DC power supply leakage.

[0065] In this context, DC power supply overcurrent refers to the current of the DC power supply reaching the overcurrent threshold. This overcurrent threshold is greater than the rated current of the DC power supply during normal operation. DC power supply overtemperature refers to the temperature of the DC power supply exceeding the overtemperature threshold. Abnormal combustible gas concentration within the DC power supply refers to the concentration of combustible gas within the DC power supply (such as within a battery pack) exceeding the concentration threshold. In this embodiment, the anomaly detection circuit 12 includes multiple current detection circuits 122, multiple temperature detection circuits 123, multiple gas detection circuits 124, and / or multiple leakage detection circuits 125, enabling redundant detection of the current, temperature, combustible gas concentration, and leakage status of the DC power supply. This effectively improves the accuracy and reliability of anomaly detection, thereby effectively reducing the probability of malfunction of the circuit breaker 20.

[0066] In one possible implementation, the charging circuit 11, the fault detection circuit 12, and the driving circuit 13 in the circuit breaker drive can all be composed of discrete components, meaning that the circuit breaker drive does not require integrated circuits (ICs), such as a microcontroller unit (MCU). This ensures that the hardware cost and power consumption of the circuit breaker drive are low.

[0067] In one possible implementation, the electrical device provided in this application embodiment is a battery pack. For example... Figure 4As shown, the battery pack also includes multiple battery cells 30, and the multiple battery cells 30 and the circuit breaker 20 are connected in series between the positive terminal BAT+ and the negative terminal BAT- of the battery pack. In this embodiment, a DC power supply abnormality can also be referred to as a battery pack abnormality. Accordingly, the circuit breaker drive device 10 is used to drive the circuit breaker 20 to open when the battery pack is abnormal, thereby disconnecting the power circuit of the battery pack.

[0068] Continue to refer to Figure 4 The battery pack also includes a busbar 40, which connects the positive terminal BAT+ and the negative terminal BAT- of the battery pack. A circuit breaker drive unit 10 is connected to the busbar 40 and is used to draw power from the busbar 40. For example, the third switch K3 of the charging circuit 11 in the circuit breaker drive unit 10 is connected to the busbar 40 and can draw power from the busbar 40 to charge the energy storage capacitor C0.

[0069] In one possible implementation, such as Figure 4 As shown, the battery pack also includes a BMU, which can be connected to some or all of the detection circuits in the anomaly detection circuit 12. For example, the BMU can be connected to the temperature detection circuit 123, the gas detection circuit 124, and / or the leakage detection circuit 125, and can acquire the temperature detected by the temperature detection circuit 123, the concentration of combustible gas detected by the gas detection circuit 124, and / or the leakage situation detected by the leakage detection circuit 125.

[0070] Figure 6 This is a schematic diagram illustrating the working principle of a circuit breaker drive device in a battery pack according to an embodiment of this application. Figure 6 As shown, the circuit breaker drive device 10 can charge the energy storage capacitor C0 when the battery pack voltage Vbat is greater than the first voltage threshold Vp1, or when the battery pack experiences abnormalities such as overcurrent, overtemperature, or leakage. Furthermore, when the voltage of the energy storage capacitor C0 is greater than the second voltage threshold Vp2, and the battery pack is abnormal, the circuit breaker drive device can drive the circuit breaker 20 to disconnect the main power circuit of the battery pack. (Refer to...) Figure 6 Battery pack abnormality can refer to abnormalities such as overcurrent, overtemperature, or leakage in the battery pack, or it can refer to the two voltage detection circuits 121 in the battery pack both detecting overvoltage in the battery pack, that is, both detecting that the voltage Vbat of the battery pack is greater than the overvoltage threshold Vp3.

[0071] In one possible implementation, the electrical device provided in this application embodiment is a cluster control box, such as... Figure 5As shown, the cluster control box also includes a cluster switch K0. The cluster switch K0 is used to connect between the battery cluster and the power converter (e.g., PCS), and the circuit breaker 20 is also used to connect between the battery cluster and the power converter (e.g., PCS). In this embodiment, the DC power supply is the battery cluster, and correspondingly, the circuit breaker drive device 10 is used to drive the circuit breaker 20 to open when the battery cluster malfunctions, thereby disconnecting the main power circuit of the battery cluster. The battery cluster malfunction may include overvoltage and / or overcurrent.

[0072] For example, such as Figure 5 As shown, the cluster control box also includes a battery input busbar 50. Busbar 50 connects the positive terminal BAT+ and the negative terminal BAT- of the battery cluster. A circuit breaker drive unit 10 is connected to busbar 50 and is used to draw power from busbar 50. For example, the third switch K3 in the charging circuit 11 is connected to busbar 50 and can draw power from busbar 50 to charge the energy storage capacitor C0.

[0073] In one possible implementation, such as Figure 5 As shown, the cluster control box is used to connect the power converter via the DC bus (BUS+, BUS-). The cluster switch K0 is connected between the positive terminal BAT+ of the battery cluster and the positive bus BUS+, and the circuit breaker 20 is connected between the negative terminal BAT- of the battery cluster and the negative bus BUS-.

[0074] The cluster control box provided in this application embodiment also includes a cluster controller ( Figure 5 (Not shown in the image), this cluster controller is used to control the on / off state of cluster switch K0.

[0075] In one possible implementation, the electrical device provided in this application embodiment is a power converter, which can be a PCS or an inverter. Figure 7 As shown, the power converter also includes a power conversion circuit 60. The DC terminal of the power conversion circuit 60 is connected to a DC power source, and the AC terminal is used to connect to the power grid or a load. The power conversion circuit 60 is used to convert the DC power from the DC power source into AC power for output. Alternatively, the power conversion circuit 60 can also be used to convert AC power into DC power to charge the DC power source. The DC power source can be a battery pack or battery cluster.

[0076] For example, such as Figure 7 As shown, the DC terminals of the power conversion circuit 60 are connected to the DC bus (BUS+, BUS-), which is used to connect to a DC power supply. The circuit breaker 20 is connected between the DC bus (BUS+, BUS-) and the DC terminals of the power conversion circuit 60, for example, between the negative bus BUS- and the negative terminal of the DC power conversion circuit 60.

[0077] In this embodiment, the DC power supply abnormality can also be referred to as a DC terminal abnormality of the power conversion circuit 60, and the abnormality may include overvoltage and / or overcurrent. Accordingly, the circuit breaker drive device 10 is used to drive the circuit breaker 20 to open when there is overvoltage or overcurrent at the DC terminal of the power conversion circuit 60, thereby disconnecting the power circuit on the DC side of the power conversion circuit 60.

[0078] In this embodiment, the power conversion circuit 60 may include a DC / DC conversion circuit and a DC / AC conversion circuit. One end of the DC / DC conversion circuit is connected to the DC bus (BUS+, BUS-), and the other end is connected to the DC terminal of the DC / AC conversion circuit. The AC terminal of the DC / AC conversion circuit is used to connect to the power grid or a load. Alternatively, the power conversion circuit 60 may include a DC / AC conversion circuit but not a DC / DC conversion circuit, with the DC terminal of the DC / AC conversion circuit directly connected to the DC bus (BUS+, BUS-).

[0079] In one possible implementation, the circuit breaker 20 in the electrical equipment can be an active tripping fuse, also known as an explosive fuse. Using an active tripping fuse as the circuit breaker 20 ensures that the circuit breaker has a simpler structure, smaller size, and faster response speed, enabling it to quickly trip in fault scenarios.

[0080] In one possible implementation, the anomaly detection circuit 12 may be powered by an energy storage capacitor C0 and / or a DC power supply. (See reference...) Figure 4 and Figure 5 Some or all of the detection circuits in the anomaly detection circuit 12 can be directly connected to the busbar and powered by the busbar. Another part or all of the detection circuits in the anomaly detection circuit 12 can also be connected to an energy storage capacitor C0. When the voltage of the energy storage capacitor C0 is greater than a certain threshold (such as the first voltage threshold mentioned above), the energy storage capacitor C0 can power the other part or all of the detection circuits. For example, multiple voltage detection circuits 121 in the anomaly detection circuit 12 can be powered by the energy storage capacitor C0.

[0081] In summary, this application provides an electrical device that uses an energy storage capacitor to power the drive circuit. Compared to magnetic coupling devices such as isolation transformers, the energy storage capacitor is smaller in size, ensuring a smaller footprint for the circuit breaker drive device. Furthermore, by drawing power from a DC power source through a charging circuit to charge the energy storage capacitor, and then using the energy storage capacitor to power the drive circuit, the power supply quality of the drive circuit is ensured to be unaffected by the amplitude of the AC component of the DC power current. This ensures high power supply stability for the drive circuit, thereby ensuring high reliability when the drive circuit trips the circuit breaker. Moreover, since the charging circuit of this drive device only charges the energy storage capacitor when it detects a high DC power supply voltage or an abnormal DC power supply, allowing the energy storage capacitor to then power the drive circuit, the power consumption of the drive device is also kept low, avoiding impact on the performance of the DC power supply (such as a battery pack), and thus avoiding impact on the charging and discharging efficiency of the energy storage system.

[0082] Furthermore, the anomaly detection circuit in this electrical device can autonomously detect abnormal conditions in the DC power supply, thereby ensuring the active disconnection of the DC power supply circuit without relying on an external controller. In the scenario where the electrical device is a battery pack, the external controller can refer to the BMU within the battery pack.

[0083] This application also provides an energy storage system, such as... Figure 1 and Figure 8 As shown, the energy storage system includes a battery cluster and a cluster control box. The battery cluster comprises multiple battery packs connected in series, for example, 2 to 12 battery packs connected in series.

[0084] like Figure 8 As shown, in industrial and commercial or power plant scenarios, the energy storage system may also include a power converter (such as a PCS), with a cluster control box connected between the battery clusters and the PCS. In industrial and commercial or charging station scenarios, the energy storage system may also include a DC / DC converter. In some industrial and commercial scenarios, the DC / DC converter is connected between the cluster control box and the PCS. In charging station scenarios, the energy storage system may not include a PCS; the battery clusters are connected to the DC / DC converter via the cluster control box.

[0085] from Figure 8 It can be seen that the battery clusters, cluster control boxes, and / or PCS in the energy storage system can adopt the solutions provided in the embodiments of this application. That is, the battery clusters, cluster control boxes, and / or PCS can be equipped with the circuit breaker 20 and circuit breaker drive device 10 described in the above embodiments.

[0086] For example, see reference Figure 9The battery cluster comprises N battery packs connected in series, where N is an integer greater than 1. Each battery pack is equipped with a circuit breaker 20 and a circuit breaker drive device 10, thereby enabling protection of a single battery pack. When the circuit breaker 20 is located in the cluster control box and / or PCS, i.e., in the main circuit of the energy storage system, the circuit breaker drive device 10 can detect the voltage and current of the main circuit of the energy storage system and be used to protect the entire cluster energy storage system.

[0087] In the embodiments of this application, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "at least one" refers to one or more, and "multiple" refers to two or more.

[0088] In the embodiments of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0089] The above description is merely an optional implementation of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered 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. An electrical device, characterized by The electrical equipment includes: a charging circuit, an abnormality detection circuit, an energy storage capacitor, a drive circuit, and a circuit breaker; One end of the charging circuit is connected to a DC power supply, and the other end of the charging circuit is connected to the energy storage capacitor. The charging circuit is used to charge the energy storage capacitor when the abnormality detection circuit detects an abnormality in the DC power supply. The energy storage capacitor is connected to the driving circuit, and the energy storage capacitor is used to supply power to the driving circuit. The circuit breaker is connected in series between the positive and negative terminals of the DC power supply, and the drive circuit is used to drive the circuit breaker to disconnect when the DC power supply is abnormal. The abnormal DC power supply includes at least one of the following: overvoltage, overcurrent, overtemperature, leakage, and abnormal concentration of combustible gas.

2. The electrical device of claim 1, wherein, The drive circuit includes a first switch, which is connected in series between the energy storage capacitor and the circuit breaker. The first switch is used to disconnect when the DC power supply is not abnormal and to connect when the DC power supply is abnormal.

3. The electrical equipment according to claim 2, characterized in that, The drive circuit also includes a second switch, and the first switch and the second switch are connected in series between the energy storage capacitor and the circuit breaker. The second switch is used to disconnect when the voltage of the energy storage capacitor is less than or equal to a first voltage threshold, and to turn on when the voltage of the energy storage capacitor is greater than the first voltage threshold.

4. The electrical device according to any one of claims 1 to 3, characterized in that The charging circuit includes a first charging branch and a second charging branch. One end of the first charging branch is used to connect to the DC power supply, and the other end of the first charging branch is connected to the energy storage capacitor. The first charging branch is used to charge the energy storage capacitor when the voltage of the DC power supply is greater than the second voltage threshold. The first end of the second charging branch is used to connect to the DC power supply, the second end of the second charging branch is connected to the energy storage capacitor, and the third end of the second charging branch is connected to the abnormality detection circuit. The second charging branch is used to charge the energy storage capacitor when the abnormality detection circuit detects an abnormality in the DC power supply. Wherein, the second voltage threshold is greater than the rated voltage of the DC power supply and less than the overvoltage threshold of the DC power supply.

5. The electrical device of claim 4, wherein, The first charging branch includes a Zener diode, the negative terminal of which serves as one end of the first charging branch and is connected to the positive terminal of the DC power supply, and the positive terminal of which serves as the other end of the first charging branch and is connected to the energy storage capacitor.

6. The electrical device of claim 4, wherein, The second charging branch includes a switching transistor. The first terminal of the switching transistor serves as the first terminal of the second charging branch and is connected to the DC power supply. The second terminal of the switching transistor serves as the second terminal of the second charging branch and is connected to the energy storage capacitor. The control terminal of the switching transistor serves as the third terminal of the second charging branch and is connected to the abnormal detection circuit.

7. The electrical equipment according to any one of claims 1 to 3, characterized in that, The anomaly detection circuit includes multiple voltage detection circuits; The abnormality detection circuit detects the DC power supply abnormality by including: all of the multiple voltage detection circuits detecting overvoltage in the DC power supply.

8. The electrical equipment according to any one of claims 1 to 3, characterized in that, The anomaly detection circuit includes multiple current detection circuits, multiple temperature detection circuits, multiple leakage detection circuits, and multiple gas detection circuits; the anomaly detection circuit detects at least one of the following anomalies in the DC power supply: All of the multiple current detection circuits detected overcurrent in the DC power supply. All of the multiple temperature detection circuits detected that the DC power supply was overheated. All of the multiple leakage detection circuits detected leakage from the DC power supply. All of the gas detection circuits detected an abnormal concentration of combustible gas in the DC power supply.

9. The electrical equipment according to any one of claims 1 to 3, characterized in that, The electrical equipment is a battery pack, which further includes multiple battery cells, and the DC power supply is the multiple battery cells.

10. The electrical equipment according to any one of claims 1 to 3, characterized in that, The electrical equipment is a cluster control box, which also includes a cluster switch for connecting the battery cluster and the power converter. The DC power supply is the battery cluster.

11. The electrical device according to any one of claims 1 to 3, characterized in that The electrical equipment is a power converter, which further includes a power conversion circuit. The DC terminal of the power conversion circuit is used to connect to the DC power supply, and the power conversion circuit is used to convert the DC power from the DC power supply into AC power. The DC power supply is a battery pack or battery cluster.

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