Driving circuit, direct-current power conversion device and energy storage system

Abstract

The utility model provides a driving circuit, a direct-current power conversion device and an energy storage system, and is applied to the technical field of energy storage, the energy storage system comprises a direct-current power conversion circuit, a main power switch and an energy storage battery which are connected in sequence, and the driving circuit comprises an AND logic driving circuit. The AND logic driving circuit is respectively connected with the energy storage battery, the direct-current power conversion circuit and the main power switch and is used for receiving a first fault control signal output by the energy storage battery and a second fault control signal output by the direct-current power conversion circuit, and the output end of the AND logic driving circuit is connected with the control end of the main power switch. The energy storage battery can directly provide the first fault control signal for the AND logic driving circuit without intermediate processing of the DC power conversion circuit, so that the control path of the main power switch is effectively shortened, the fault response efficiency of the energy storage battery is improved, the fault is prevented from being further expanded, and the safety of the energy storage system is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, in particular to a driving circuit, a direct current power conversion device and an energy storage system. BACKGROUND

[0002] The energy storage system composed of energy storage batteries and direct current power conversion circuits has been widely used in recent years due to the advantages that each different battery cluster can achieve 100% maximum discharge depth, supports multiple power supply sources and mixed use of new and old battery clusters, and single battery cluster failure does not affect the operation of other battery clusters.

[0003] However, the response efficiency of the existing technology to the energy storage battery failure is low, which easily causes the failure to expand and affects the safety of the entire energy storage system. CONTENT OF THE UTILITY MODEL

[0004] Therefore, the present application aims to provide a driving circuit, a direct current power conversion device and an energy storage system to solve the problem of low response efficiency of the existing technology to the energy storage battery failure and affect the safety of the energy storage system.

[0005] In a first aspect, the present application provides a driving circuit applied to an energy storage system, wherein the energy storage system comprises a direct current power conversion circuit, a main power switch and an energy storage battery connected in sequence, and the driving circuit comprises a logical driving circuit, wherein

[0006] The first input end of the logical driving circuit is connected with the fault control end of the energy storage battery to receive a first fault control signal output by the energy storage battery;

[0007] The second input end of the logical driving circuit is connected with the fault control end of the direct current power conversion circuit to receive a second fault control signal output by the direct current power conversion circuit;

[0008] The output end of the logical driving circuit is connected with the control end of the main power switch.

[0009] In an optional embodiment, the logical driving circuit comprises an AND gate circuit, wherein

[0010] The first input end of the AND gate circuit is connected with the fault control end of the energy storage battery;

[0011] The second input end of the AND gate circuit is connected with the fault control end of the direct current power conversion circuit;

[0012] The output end of the AND gate circuit serves as the output end of the logical driving circuit.

[0013] In an optional embodiment, the logical driving circuit further comprises an isolation circuit, wherein

[0014] The input end of the isolation circuit is connected with the fault control end of the energy storage battery, and the output end of the isolation circuit is connected with the first input end of the AND gate circuit.

[0015] In an alternative embodiment, the isolation circuit comprises an optocoupler and a pull-down resistor, wherein,

[0016] The control side input end of the optocoupler serves as the input end of the isolation circuit, and the control side output end of the optocoupler is grounded.

[0017] The controlled side input end of the optocoupler receives a first working voltage, the controlled side output end of the optocoupler is connected with one end of the pull-down resistor, and the other end of the pull-down resistor is grounded.

[0018] The connection point of the optocoupler and the pull-down resistor serves as the output end of the isolation circuit.

[0019] In an alternative embodiment, the energy storage system further comprises a pre-charge circuit connected in parallel with the main power switch, and the drive circuit further comprises a pre-charge drive circuit, wherein,

[0020] The output end of the pre-charge drive circuit is connected with the control end of the pre-charge circuit, and the input end of the pre-charge drive circuit receives a pre-charge start signal or a pre-charge stop signal.

[0021] The pre-charge start signal drives the pre-charge circuit to be turned on, and the pre-charge stop signal drives the pre-charge circuit to be turned off.

[0022] In an alternative embodiment, the pre-charge drive circuit comprises a pull-up resistor and a first controllable switch, wherein,

[0023] One end of the pull-up resistor is used to receive a second working voltage, the other end of the pull-up resistor is connected with the first end of the first controllable switch, and the first end of the first controllable switch is connected with the control end of the pre-charge circuit.

[0024] The second end of the first controllable switch is grounded.

[0025] The control end of the first controllable switch is used to receive the pre-charge start signal or the pre-charge stop signal.

[0026] In an alternative embodiment, the pre-charge circuit comprises a current-limiting resistor and a second controllable switch, wherein,

[0027] The current-limiting resistor and the second controllable switch are connected in series to form a series branch.

[0028] The series branch is connected in parallel with the main power switch.

[0029] The control end of the second controllable switch is used as the control end of the pre-charge circuit.

[0030] In an alternative embodiment, the main power switch comprises an N-type metal oxide semiconductor (MOS) tube.

[0031] In a second aspect, the application provides a direct-current power conversion device, comprising a direct-current power conversion circuit, a main power switch, a pre-charge circuit, and a driving circuit as described in any one of the first aspect of the application, wherein,

[0032] One end of the main power switch is connected to a low-voltage side of the direct-current power conversion circuit, and the other end of the main power switch is used for connecting an energy storage battery.

[0033] The pre-charge circuit is connected in parallel with the main power switch.

[0034] The driving circuit is connected to the direct-current power conversion circuit, the main power switch, the pre-charge circuit, and the energy storage battery, respectively.

[0035] In a third aspect, the application provides an energy storage system, comprising an energy storage converter, an energy storage battery, and a direct-current power conversion device as described in the second aspect of the application, wherein,

[0036] The direct-current power conversion device is connected between the direct-current side of the energy storage converter and the energy storage battery.

[0037] Based on the above, the driving circuit provided by the application is applied to an energy storage system, which comprises a direct-current power conversion circuit, a main power switch, and an energy storage battery connected in sequence. The driving circuit comprises an AND logic driving circuit. A first input end of the AND logic driving circuit is connected to a fault control end of the energy storage battery to receive a first fault control signal output by the energy storage battery. A second input end of the AND logic driving circuit is connected to a fault control end of the direct-current power conversion circuit to receive a second fault control signal output by the direct-current power conversion circuit. An output end of the AND logic driving circuit is connected to a control end of the main power switch. Compared with the prior art, the energy storage battery can directly provide the first fault control signal to the AND logic driving circuit without the intermediate processing of the direct-current power conversion circuit, effectively shortening the control path of the main power switch, improving the response efficiency of the energy storage battery fault, preventing the fault from further expanding, and helping to improve the safety of the energy storage system.

[0038] Further, the energy storage battery and the direct-current power conversion circuit can both provide fault control signals to the logic driving circuit, thereby realizing redundant control of the main power switch and further improving the safety of the energy storage system. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0040] Figure 1 is a structural schematic diagram of an energy storage system in the prior art.

[0041] Figure 2 is a schematic diagram of a driving circuit provided by the present application.

[0042] Figure 3 is a circuit topology diagram of a driving circuit provided by the present application.

[0043] Figure 4 is a circuit topology diagram of another driving circuit provided by the present application.

[0044] Figure 5 is a schematic diagram of another driving circuit provided by the present application.

[0045] Figure 6 is a circuit topology diagram of still another driving circuit provided by the present application.

[0046] Figure 7 is a circuit topology diagram of yet another driving circuit provided by the present application.

[0047] Figure 8 is a structural schematic diagram of a direct-current power conversion device provided by the present application.

[0048] Figure 9 is a structural block diagram of an energy storage system provided by the present application. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0050] In combination with Figure 1 As shown in the figure, in actual application, the energy storage battery is connected with the direct-current power conversion circuit through the main power switch K1, and the main power switch K1 is also connected in parallel with a pre-charge circuit, which prevents the impact of large current at the starting moment of the energy storage battery on the energy storage battery or the low-voltage side bus capacitor C1 through the pre-charge circuit.

[0051] In the prior art, the main power switch K1 of the energy storage system is controlled by the direct current power conversion circuit. If the energy storage battery fails, a fault signal needs to be transmitted to the direct current power conversion circuit. After receiving the fault signal, the direct current power conversion circuit outputs a driving signal to the main power switch K1 to drive the main power switch K1 to be disconnected. Obviously, this processing mechanism has low response efficiency to the energy storage battery failure, is easy to cause the failure to be expanded, and affects the safety of the entire energy storage system.

[0052] To solve the above problems, the application provides a driving circuit, which comprises an and logic driving circuit. The energy storage battery can directly provide a first fault control signal to the and logic driving circuit without the intermediate processing of the direct current power conversion circuit. The control path of the main power switch is effectively shortened, the response efficiency of the energy storage battery failure is improved, the failure is prevented from being further expanded, and the safety of the energy storage system is improved.

[0053] The driving circuit provided by the application is applied to an energy storage system, including a household photovoltaic energy storage system in actual application, and in combination with Figure 2 As shown in the figure, the energy storage system comprises a direct current power conversion circuit, a main power switch K1 and an energy storage battery. The positive electrode of the low-voltage side of the direct current power conversion circuit is connected with one end of the main power switch K1. The other end of the main power switch K1 is connected with the positive electrode of the energy storage battery. The negative electrode of the energy storage battery is connected with the negative electrode of the low-voltage side of the direct current power conversion circuit, thereby forming a complete closed loop. The high-voltage side of the direct current power conversion circuit is connected with other devices in the energy storage system, which is not described here.

[0054] In actual application, the direct current power conversion circuit can be a DC / DC power conversion circuit. It needs to be noted that the direct current power conversion circuit described in the application comprises a control module on the basis of a power conversion main circuit. The related control signals provided by the direct current power conversion circuit described in the subsequent content of the application are all provided by the control module. As an optional implementation manner, the control module in the direct current power conversion circuit can be realized by a DSP (Digital Signal Processor). Of course, other controllers capable of realizing the same function can also be selected. The specific implementation of the control module is not limited in the application.

[0055] The main power switch K1 can be selected as a controllable switch. In actual application, MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), IGBT (Insulate-Gate Bipolar Transistor) and relay can be selected according to the current size of the energy storage system and other factors. Any controllable switch that can respond to a control signal and change its conduction state is optional, and will not be listed one by one here.

[0056] The energy storage battery usually includes a plurality of battery clusters and a BMS (Battery Management System). According to related technologies, the main function of the BMS is to intelligently manage and maintain each battery module of the energy storage battery, monitor the state of the energy storage battery, prevent overcharging or overdischarging of the energy storage battery, and also can collect working parameters such as voltage, current and temperature of each battery cluster. Based on the obtained working parameters, it is determined whether the energy storage battery is in a fault state, and in the case that the energy storage battery is in a fault state, a control signal or notification information is output. Based on this, the control signal or control action related to the energy storage battery mentioned in the subsequent content of the present application is realized by the BMS.

[0057] Further, the energy storage system is also provided with a low-voltage side bus capacitor C1 and a pre-charge circuit. As shown in Figure 2 The low-voltage side bus capacitor C1 is connected in parallel to the low-voltage side of the direct-current power conversion circuit, and the pre-charge circuit is connected in parallel to the main power switch K1. In actual application, the low-voltage side bus capacitor C1 is mainly used to cooperate with the pre-charge circuit to raise the low-voltage side bus voltage, and also can play a filtering role. In the case that the pre-charge circuit is turned on, the low-voltage side bus capacitor C1 is charged with a small current through the current limiting effect of the pre-charge circuit, and in the case that the pre-charge circuit is turned off, the current no longer passes through the pre-charge circuit. The specific application of the pre-charge circuit in the energy storage system will be described in detail in the subsequent content, which will not be described here.

[0058] The driving circuit provided by the present application is applied to the energy storage system provided by the above content, and as shown in Figure 2 The driving circuit provided by the present application includes a logic drive circuit 10.

[0059] The logic driving circuit 10 is configured with a first input end, a second input end and an output end. The first input end of the logic driving circuit 10 is connected with a fault control end of the energy storage battery, and in an optional embodiment, the first input end of the logic driving circuit 10 is connected with a fault control end of a BMS in the energy storage battery. The second input end of the logic driving circuit 10 is connected with a fault control end of the DC power conversion circuit, and in an optional embodiment, the second input end of the logic driving circuit 10 is connected with a fault control end of a control module in the DC power conversion circuit. The output end of the logic driving circuit 10 is connected with a control end of the main power switch K1.

[0060] As described above, the BMS of the energy storage battery can detect the running state of the energy storage battery based on the electrical parameters of the energy storage battery. In the case of determining that the energy storage battery is running abnormally, i.e., in a fault state, the BMS of the energy storage battery outputs a first fault control signal.

[0061] Further, the DC power conversion circuit can participate in the control of the on state of the main power switch K1. In the case of needing to control the main power switch K1 to be off, the control module of the DC power conversion circuit outputs a second fault control signal. It can be understood that in actual application, there are many cases of needing to control the main power switch K1 to be off, for example, the energy storage system needs to be powered off, for example, the DC power conversion circuit needs to be disconnected from the energy storage battery to prevent the fault from further expanding, and of course, other cases of needing the main power switch K1 to be off can also be included, which will not be listed one by one here.

[0062] The logic driving circuit 10 is connected with the DC power conversion circuit and the energy storage battery respectively, and receives at least one of the first fault control signal and the second fault control signal, i.e., the energy storage battery and the DC power conversion circuit can both provide the fault control signal to the logic driving circuit 10. Especially for the energy storage battery, the first fault control signal can be directly output to the logic driving circuit 10 without passing through the intermediate processing of the DC power conversion circuit.

[0063] The logic driving circuit 10 drives the main power switch K1 to be off in response to at least one of the first fault control signal and the second fault control signal. In actual application, the specific implementation mode of the logic driving circuit 10 driving the main power switch K1 to be off is related to the specific implementation of the main power switch K1, for example, in an optional embodiment, the main power switch K1 is implemented by using an N-type MOS tube, and the logic driving circuit 10 can control the main power switch K1 to be off by providing a low-level driving signal to the main power switch K1.

[0064] In summary, compared with the prior art, in the driving circuit provided by the application, the energy storage battery can directly provide the first fault control signal to the logic driving circuit, and the logic driving circuit can drive the main power switch to be turned off in response to the first fault control signal, without the intermediate processing of the DC power conversion circuit, effectively shortening the control path of the main power switch, improving the response efficiency of the energy storage battery fault, preventing the fault from further expanding, and helping to improve the safety of the energy storage system.

[0065] Further, the energy storage battery and the DC power conversion circuit can both provide the fault control signal to the logic driving circuit, and the logic driving circuit can also drive the main power switch to be turned off when at least one of the first fault control signal and the second fault control signal exists, that is, the energy storage battery and the DC power conversion circuit can both drive the main power switch to be turned off, thereby realizing redundant control of the main power switch and further improving the safety of the energy storage system.

[0066] The application provides another driving circuit, as shown in Figure 3 In the driving circuit provided in the embodiment, the logic driving circuit 10 includes an AND gate circuit 110.

[0067] Specifically, the AND gate circuit 110 includes a first input end, a second input end, and an output end. The first input end of the AND gate circuit 110 serves as the first input end of the logic driving circuit 10 and is connected to the fault control end of the energy storage battery to receive the first fault control signal output by the energy storage battery. The second input end of the AND gate circuit 110 serves as the second input end of the logic driving circuit 10 and is connected to the fault control end of the DC power conversion circuit to receive the second fault control signal provided by the DC power conversion circuit. Further, the output end of the AND gate circuit 110 serves as the output end of the logic driving circuit 10 and is connected to the control end of the main power switch K1.

[0068] Based on the above connection relationship and the working characteristics of the AND gate, the first fault control signal and the second fault control signal are both low. When the AND gate circuit 110 receives at least one of the first fault control signal and the second fault control signal, the AND gate circuit 110 outputs a low level to drive the main power switch K1 to be turned off, without the intermediate processing of the DC power conversion circuit, effectively shortening the control path of the main power switch, improving the response efficiency of the energy storage battery fault, preventing the fault from further expanding, and helping to improve the safety of the energy storage system.

[0069] Further, the application provides another driving circuit, as shown in Figure 4 The logic driving circuit 10 includes an AND gate circuit 110 and an isolation circuit 120.

[0070] As an optional implementation, the isolation circuit 120 comprises an optocoupler U1 and a pull-down resistor R3, wherein the control side input end of the optocoupler U1 is connected to the fault control end of the energy storage battery as the input end of the isolation circuit 120, i.e., as the first input end of the logic drive circuit 10, the control side output end of the optocoupler U1 is grounded, the controlled side input end of the optocoupler U1 receives the first working voltage V1, the controlled side output end of the optocoupler U1 is connected to one end of the pull-down resistor R3, the other end of the pull-down resistor R3 is grounded, and the connection point of the controlled side output end of the optocoupler U1 and the pull-down resistor R3 is the output end of the isolation circuit 120 and is connected to the first input end of the AND gate circuit 110. It should be noted that the first working voltage V1 can be provided in various ways. In an optional implementation, a working power supply can be separately arranged to provide the first working voltage V1. In another optional implementation, the first working voltage V1 can be provided by the power distribution network of the energy storage system. Of course, the first working voltage V1 can also be provided in other ways, which will not be described one by one here. The specific implementation of the first working voltage V1 is not limited in the present application.

[0071] The second input end of the AND gate circuit 110, as the second input end of the logic drive circuit 10, is connected to the fault control end of the DC power conversion circuit to receive the second fault control signal, and the output end of the AND gate circuit 110, as the output end of the logic drive circuit 10, is connected to the control end of the main power switch K1.

[0072] The working process of the drive circuit provided in the present embodiment will be described below by taking the case where the main power switch K1 is implemented based on an N-type MOS tube.

[0073] The energy storage battery outputs a low level through the fault control end in a fault state, i.e., the first fault control signal. In response to the first fault control signal, the control side diode of the optocoupler U1 is turned off, and accordingly, the controlled side of the optocoupler U1 is also turned off. The isolation circuit 120 outputs a low level to the AND gate circuit 110. Based on the working principle of the AND gate circuit 110, the AND gate circuit 110 outputs a low level in the case where any input end receives a low level. The N-type MOS tube is turned off in the case where the gate receives a low level, i.e., the main power switch K1 is turned off.

[0074] Correspondingly, the energy storage battery outputs a high level through the fault control terminal in a normal state, i.e. a third fault control signal. In response to the third fault control signal, the optocoupler U1 controls the side diode to be turned on, and correspondingly, the controlled side of the optocoupler U1 is turned on, and the isolation circuit 120 outputs a high level to the AND gate circuit 110. In this case, if the DC power conversion circuit determines that the main power switch K1 needs to be turned off, a low level, i.e. a second fault control signal, is output to the AND logic drive circuit 10. Based on the working principle of the AND gate circuit 110, the AND gate circuit 110 outputs a low level to drive the main power switch K1 to be turned off.

[0075] It can be understood that the main power switch can be turned on only when the energy storage battery and the DC power conversion circuit both output a high level. In this way, it can be ensured that the energy storage system is started only when the energy storage battery and the DC power conversion circuit are both in a normal state, which helps to improve the safety and reliability of the energy storage system.

[0076] It can also be understood that, as another optional embodiment, the main power switch K1 can also be implemented by using a P-type MOS tube. In this case, the AND logic drive circuit 10 can control the main power switch K1 to be turned off by providing a high level drive signal to the main power switch K1.

[0077] In summary, based on the drive circuit provided in the embodiment, the energy storage battery can drive the main power switch to be turned off through the AND logic drive circuit in a fault state without the intermediate processing of the DC power conversion circuit, which improves the fault processing efficiency. Moreover, the energy storage battery and the DC power conversion circuit can both independently control the main power switch K1 to be turned off, thereby realizing the redundant control of the main power switch K1.

[0078] Further, the present application provides another drive circuit, which is combined with Figure 5 As shown in FIG. 6, the drive circuit provided in the embodiment includes an AND logic drive circuit 10 and a pre-charge drive circuit 20.

[0079] The connection mode and working process of the AND logic drive circuit 10 can be referred to the related content of the foregoing embodiment, which will not be repeated here.

[0080] The output terminal of the pre-charge drive circuit 20 is connected to the control terminal of the pre-charge circuit. The input terminal of the pre-charge drive circuit 20 is used to receive a pre-charge start signal or a pre-charge stop signal. The pre-charge start signal is used to drive the pre-charge circuit to be turned on, and the pre-charge stop signal is used to drive the pre-charge circuit to be turned off. Specifically, in response to the pre-charge start signal, the pre-charge drive circuit 20 drives the pre-charge circuit to be turned on to start the pre-charge process. Correspondingly, in response to the pre-charge stop signal, the pre-charge drive circuit 20 drives the pre-charge circuit to be turned off to stop the pre-charge process.

[0081] In one optional embodiment, the aforementioned precharge start signal and precharge stop signal are provided by the BMS of the energy storage battery, i.e., the precharge process is controlled by the energy storage battery. In another optional embodiment, the precharge start signal and precharge stop signal are provided by the control module in the DC-DC power conversion circuit, i.e., the precharge process is controlled by the DC-DC power conversion circuit.

[0082] based on Figure 5 The embodiment shown illustrates another driving circuit provided in this application. In this embodiment, the pre-charge driving circuit 20 includes a pull-up resistor and a first controllable switch. See also... Figure 6 As shown, as an optional implementation, the first controllable switch is selected from transistor Q1. Of course, other types of controllable switches can also be selected, which will not be detailed here. As long as they do not exceed the core idea of ​​this application, they also fall within the scope of protection of this application. The actual resistance value of the pull-up resistor R1 needs to be selected in combination with parameters such as the second working voltage V2 and the on-resistance of transistor Q1. This application does not limit the specific value of the pull-up resistor R1.

[0083] Specifically, one end of the pull-up resistor R1 is used to receive the second operating voltage V2, and the other end of the pull-up resistor R1 is connected to the first terminal of the first controllable switch, i.e., the collector of transistor Q1. Simultaneously, the collector of transistor Q1 is also connected to the drive terminal of the pre-charge circuit. The emitter of transistor Q1 serves as the second terminal of the first controllable switch and is connected to ground. The base of transistor Q1 serves as the control terminal of the first controllable switch and is connected to the fault control terminal of the energy storage battery, receiving the pre-charge start signal or pre-charge stop signal provided by the energy storage battery. The specific implementation of the second operating voltage V2 can refer to the aforementioned implementation of the first operating voltage V1, and will not be repeated here.

[0084] In one alternative implementation, the pre-charging circuit includes a current-limiting resistor R2 and a second controllable switch K2, combined with Figure 6 As shown, the current-limiting resistor R2 is connected in series with the second controllable switch K2 to form a series branch. This series branch is then connected in parallel with the main power switch K1. The control terminal of the second controllable switch K2 serves as the control terminal of the pre-charge circuit and is connected to the output terminal of the pre-charge drive circuit 20. Figure 6 In the illustrated embodiment, it is connected to the collector of transistor Q1.

[0085] As an optional implementation, the second controllable switch is implemented based on a P-type MOSFET. Based on this, when the energy storage battery outputs a high level (i.e., a pre-charge start signal), in response to the pre-charge start signal, transistor Q1 turns on, pulling its collector potential low. The pre-charge drive circuit 20 provides a low level to the pre-charge circuit, the P-type MOSFET turns on, and the pre-charge circuit is in the on state, initiating the pre-charge process. The current-limiting resistor R2 is used to limit the current, preventing excessive pre-charge current and ensuring the safety of the charging process. Conversely, when the energy storage battery outputs a low level (i.e., a pre-charge stop signal), in response to the pre-charge stop signal, transistor Q1 turns off, the pre-charge drive circuit 20 provides a high level (i.e., the second operating voltage) to the pre-charge circuit, the P-type MOSFET turns off, and the pre-charge circuit is in the off state, stopping the pre-charge process.

[0086] In summary, the driving circuit provided in this embodiment can control not only the conduction state of the main power switch, but also the conduction state of the pre-charging circuit, thereby controlling the pre-charging process of the energy storage system. The driving circuit has more complete functions and improves the integration of the circuit.

[0087] The following is combined Figure 6 As shown, taking the main power switch K1 as an N-type MOSFET and the second controllable switch K2 as a P-type MOSFET as an example, the working process of the drive circuit provided in this application is described in detail.

[0088] After the energy storage system is powered on, the control module of the DC power conversion circuit performs a status self-check. If the self-check is normal, the control module outputs a high level, which is the fourth fault control signal. At the same time, the BMS in the energy storage battery also performs a self-check to ensure that the energy storage battery is in a normal state.

[0089] As described above, the purpose of the pre-charge circuit provided by the energy storage system is to prevent the impact of large current on the energy storage battery or the low-voltage bus capacitor at the starting moment of the energy storage battery, so it is preferred to control the pre-charge circuit to be turned on to pre-charge the low-voltage bus capacitor C1 before the main power switch K1 is closed. Based on this, the BMS of the energy storage battery outputs a first fault control signal, i.e. a low level, through the first control port in response to the power-on signal of the energy storage system, and the logic drive circuit 10 drives the main power switch K1 to be turned off in response to the first fault control signal. The specific process can be referred to the foregoing content, which will not be repeated here. It can be understood that the energy storage battery can not only provide the first fault control signal in a fault state, but also can provide the first fault control signal in the case where the main power switch K1 needs to be turned off. Of course, the process of turning off the main power switch K1 before pre-charging can also be completed by the direct current power conversion circuit, and the direct current power conversion circuit can output the second fault control signal as described above after self-checking is completed. Further, the BMS of the energy storage battery outputs a pre-charge start signal, i.e. a high level, through the second control port, and the pre-charge drive circuit 20 drives the pre-charge circuit to be turned on, and uses the current limiting effect of the current limiting resistor to charge the low-voltage bus capacitor C1 with a small current, so as to gradually raise the voltage of the low-voltage bus. It can be understood that during the pre-charging process, the main power switch K1 is turned off, the pre-charge circuit is turned on, and the pre-charge circuit bypasses the main power switch K1.

[0090] The BMS of the energy storage battery monitors the progress of pre-charging, and in the case where it is determined that the pre-charging process can be ended, the BMS first outputs a third fault control signal (the second control port still maintains the output of the pre-charge start signal) through the first control port, i.e. a high level. As described above, the direct current power conversion circuit outputs a fourth fault control signal in the case where the self-checking is normal, and the logic drive circuit 10 drives the main power switch K1 to be turned on in response to the third fault control signal and the fourth fault control signal. The specific process can be referred to the foregoing related content, which will not be repeated here. After the main power switch K1 is turned on, the BMS outputs a pre-charge stop signal through the second control port, and the pre-charge drive circuit 20 drives the pre-charge circuit to be turned off in response to the pre-charge stop signal, so as to stop the pre-charging process. It can be understood that in the case where the pre-charging is completed, the main power switch K1 is turned on, the pre-charge circuit is turned off, and the main power switch K1 bypasses the pre-charge circuit.

[0091] The BMS of the energy storage battery can monitor the pre-charging progress in multiple ways. In an optional embodiment, the BMS collects the capacitor voltage of the low-voltage bus capacitor C1 and the battery voltage of the energy storage battery through a voltage sampling circuit, and determines that the pre-charging process can be ended when the ratio of the capacitor voltage to the battery voltage reaches a preset target ratio, such as 90%. In another optional embodiment, the battery voltage of the energy storage battery is known and stable. Since the pre-charging circuit charges the low-voltage bus capacitor C1 through the pre-charging resistor in the on state, the pre-charging resistor and the low-voltage bus capacitor C1 form a resistor-capacitor charging circuit. In the case where the pre-charging resistor value and the low-voltage bus capacitor C1 value are determined, the charging time of the resistor-capacitor charging circuit can be calculated. Based on this, the BMS can start counting the charging time at the same time as outputting the pre-charging start signal. When the charging time reaches a preset time threshold, it is determined that the pre-charging process can be ended. The preset time threshold is determined based on the charging time of the aforementioned resistor-capacitor charging circuit.

[0092] After the above process, the energy storage system has been successfully started. If the energy storage battery fails during operation, the BMS outputs a first fault control signal, and the logic drive circuit 10 controls the main power switch K1 to be disconnected in response to the first fault control signal. Alternatively, if the DC power conversion circuit itself operates abnormally, a second fault control signal is output, which can also control the main power switch K1 to be disconnected.

[0093] In summary, through the drive circuit provided in the embodiment, the energy storage battery and the DC power conversion circuit can jointly control the pre-charging circuit and the main power switch. If the energy storage battery fails, the energy storage battery can directly control the main power switch to be disconnected, thereby cutting off the connection between the energy storage battery and the main circuit. The response efficiency is greatly improved. The redundant control scheme of the energy storage battery and the DC power conversion circuit jointly driving the main power switch can provide double protection for the energy storage battery. At the same time, a complete pre-charging process can be realized, and the functional integration is higher.

[0094] As mentioned above, the pre-charging start signal and the pre-charging stop signal can also be provided by the DC power conversion circuit. Based on this, the present application provides a drive circuit as shown in Figure 7

[0095] ​Based on the foregoing pre-charge process, before the main power switch K1 is closed, the pre-charge circuit needs to be controlled to be turned on first to pre-charge the low-voltage side bus capacitor C1. Based on this, the DC power conversion circuit outputs the second fault control signal to the AND logic drive circuit 10, the AND logic drive circuit 10 drives the main power switch K1 to be turned off, and further outputs the pre-charge start signal, that is, a high level, the pre-charge drive circuit 20 drives the pre-charge circuit to be turned on, and uses the current limiting effect of the current limiting resistor R2 to charge the low-voltage side bus capacitor C1 with a small current, and gradually raise the voltage of the low-voltage bus. It can be understood that during the pre-charge process, the main power switch K1 is turned off, the pre-charge circuit is turned on, and the pre-charge circuit bypasses the main power switch K1.

[0096] Referring to the function of the energy storage battery in the foregoing embodiment, the DC power conversion circuit monitors the progress of the pre-charge, and in the case that it is determined that the pre-charge process can be ended, the DC power conversion circuit outputs the fourth fault control signal. At the same time, the BMS in the energy storage battery also performs self-checking on the energy storage battery, and in the case that the energy storage battery is in a normal state, the foregoing third fault control signal is output. As described before, the AND logic drive circuit 10 drives the main power switch K1 to be turned on in the case that it receives the third fault control signal and the fourth fault control signal. After the main power switch K1 is turned on, the DC power conversion circuit outputs the pre-charge stop signal, and the pre-charge drive circuit 20 drives the pre-charge circuit to be turned off in response to the pre-charge stop signal, thereby stopping the pre-charge process. It can be understood that in the case that the pre-charge is completed, the main power switch K1 is turned on, the pre-charge circuit is turned off, and the main power switch K1 bypasses the pre-charge circuit.

[0097] Figure 7 Other working processes of the drive circuit shown can be referred to the related content of the foregoing embodiment, which will not be repeated here.

[0098] The application also provides a DC power conversion device, which can be referred to Figure 8 The DC power conversion device provided by the embodiment shown comprises a DC power conversion circuit, a main power switch K1, a pre-charge circuit, a low-voltage side bus capacitor C1, and the drive circuit provided by any one of the foregoing embodiments of the application, wherein,

[0099] One end of the main power switch K1 is connected to the low-voltage side of the DC power conversion circuit, and the other end of the main power switch K1 is used to connect the energy storage battery. The pre-charge circuit is connected in parallel with the main power switch K1. The low-voltage side bus capacitor C1 is connected in parallel with the low-voltage side of the DC power conversion circuit. The drive circuit is connected to the DC power conversion circuit, the main power switch K1, the pre-charge circuit, and the energy storage battery, respectively.

[0100] Further, the application also provides an energy storage system, which can be referred to Figure 9As shown, the energy storage system provided by the present application comprises a PCS (Power Conversion System), an energy storage battery, and a direct-current power conversion device as provided in the foregoing embodiments, wherein the direct-current power conversion device is connected between the direct-current side of the PCS and the energy storage battery.

[0101] Those skilled in the art can understand that the disclosed content of the present disclosure can appear in various modifications and improvements. For example, the various devices or components described above can be implemented by hardware, or by software, firmware, or a combination of some or all of the three.

[0102] In addition, although the present disclosure makes various references to certain units in the system according to the embodiments of the present disclosure, however, any number of different units can be used and run on the client and / or server. The units are only illustrative, and different aspects of the system and method can use different units.

[0103] Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0104] The above is a description of the present disclosure and should not be considered as a limitation thereof. Although several exemplary embodiments of the present disclosure are described, those skilled in the art will readily understand that many modifications can be made to the exemplary embodiments without departing from the novel teachings and advantages of the present disclosure. Therefore, all such modifications are intended to be included within the scope of the present disclosure defined by the claims. It should be understood that the above is a description of the present disclosure and should not be considered as a limitation thereof. The disclosed embodiments are not intended to be limited to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of the appended claims. The present disclosure is defined by the claims and their equivalents.

Claims

1. A driving circuit, characterized in that, The system is applied to an energy storage system, which includes a DC power conversion circuit, a main power switch, and an energy storage battery connected in sequence. The drive circuit includes an AND logic drive circuit, wherein... The first input terminal of the logic drive circuit is connected to the fault control terminal of the energy storage battery, and receives the first fault control signal output by the energy storage battery. The second input terminal of the logic drive circuit is connected to the fault control terminal of the DC power conversion circuit, and receives the second fault control signal output by the DC power conversion circuit; The output terminal of the logic drive circuit is connected to the control terminal of the main power switch.

2. The driving circuit according to claim 1, characterized in that, The AND logic driving circuit includes an AND gate circuit, wherein... The first input terminal of the AND gate circuit is connected to the fault control terminal of the energy storage battery. The second input terminal of the AND gate circuit is connected to the fault control terminal of the DC power conversion circuit; The output of the AND gate circuit serves as the output of the AND logic driver circuit.

3. The driving circuit according to claim 2, characterized in that, The logic driving circuit also includes an isolation circuit, wherein, The input terminal of the isolation circuit is connected to the fault control terminal of the energy storage battery, and the output terminal of the isolation circuit is connected to the first input terminal of the AND gate circuit.

4. The driving circuit according to claim 3, characterized in that, The isolation circuit includes: an optocoupler and a pull-down resistor, wherein, The control-side input terminal of the optocoupler serves as the input terminal of the isolation circuit, and the control-side output terminal of the optocoupler is grounded. The controlled input terminal of the optocoupler receives a first operating voltage, the controlled output terminal of the optocoupler is connected to one end of the pull-down resistor, and the other end of the pull-down resistor is grounded; The connection point between the optocoupler and the pull-down resistor serves as the output terminal of the isolation circuit.

5. The driving circuit according to claim 1, characterized in that, The energy storage system further includes a pre-charging circuit connected in parallel with the main power switch, and the drive circuit further includes a pre-charging drive circuit, wherein... The output terminal of the precharge drive circuit is connected to the control terminal of the precharge circuit, and the input terminal of the precharge drive circuit receives a precharge start signal or a precharge stop signal. The precharge start signal drives the precharge circuit to be turned on, and the precharge stop signal drives the precharge circuit to be turned off.

6. The driving circuit according to claim 5, characterized in that, The pre-charge drive circuit includes a pull-up resistor and a first controllable switch, wherein... One end of the pull-up resistor is used to receive the second working voltage, and the other end of the pull-up resistor is connected to the first end of the first controllable switch, and the first end of the first controllable switch is connected to the control end of the pre-charging circuit. The second terminal of the first controllable switch is grounded; The control terminal of the first controllable switch is used to receive the precharge start signal or the precharge stop signal.

7. The driving circuit according to claim 5 or 6, characterized in that, The pre-charging circuit includes a current-limiting resistor and a second controllable switch, wherein... The current-limiting resistor is connected in series with the second controllable switch to form a series branch; The series branch is connected in parallel with the main power switch; The control terminal of the second controllable switch serves as the control terminal of the pre-charging circuit.

8. The driving circuit according to claim 2, characterized in that, The main power switch includes an N-type metal-oxide-semiconductor MOSFET.

9. A DC power conversion device, characterized in that, include: The DC power conversion circuit, the main power switch, the pre-charge circuit, and the drive circuit as described in any one of claims 1 to 8, wherein, One end of the main power switch is connected to the low-voltage side of the DC power conversion circuit, and the other end of the main power switch is used to connect to the energy storage battery. The pre-charging circuit is connected in parallel with the main power switch; The drive circuit is connected to the DC power conversion circuit, the main power switch, the pre-charge circuit, and the energy storage battery, respectively.

10. An energy storage system, characterized in that, include: Energy storage converter, energy storage battery, and DC power conversion device as described in claim 9, wherein, The DC power conversion device is connected between the DC side of the energy storage converter and the energy storage battery.

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