Current analog device and hardware-in-the-loop test device for energy storage systems

Abstract

The application provides a current simulation device and a hardware-in-the-loop test device for an energy storage system, and relates to the technical field of battery management system testing. The current simulation device comprises an adjustable direct current voltage source and a current direction switching circuit; a voltage output positive terminal of the adjustable direct current voltage source is connected with a positive electrode of a battery cluster end of a battery management system through the current direction switching circuit, and a voltage output negative terminal is connected with a negative electrode of the battery cluster end through the current direction switching circuit; or the voltage output positive terminal of the adjustable direct current voltage source is connected with the negative electrode of the battery cluster end through the current direction switching circuit, and the voltage output negative terminal is connected with the positive electrode of the battery cluster end through the current direction switching circuit. The application realizes automatic switching of the current direction through control of the current direction switching circuit, and can simulate various current working conditions in cooperation with the adjustable direct current voltage source, improves the current response speed, greatly improves the efficiency of BMS current simulation, and thus improves the test efficiency.

Description

Technical Field

[0001] This application relates to the field of battery management system testing technology, and in particular to a current simulation device and a hardware-in-the-loop testing device for energy storage systems. Background Technology

[0002] The primary function of a Battery Management System (BMS) is to monitor, control, and protect the battery's state. Hardware-in-the-Loop (HIL) testing is a crucial aspect of BMS research and development and production. Its purpose is to verify the proper functioning of the BMS in monitoring, controlling, and protecting the battery. BMS testing includes testing current protection. The BMS collects the charging and discharging current of the battery cluster during use (e.g., current flowing into the battery cluster through the BMS during charging and current flowing out of the battery cluster through the BMS during discharging), thereby verifying the reliability of the BMS's current monitoring and protection functions (e.g., overcurrent protection). Using real battery clusters for charging and discharging during testing is costly. Therefore, it is necessary to simulate the charging and discharging current input to the BMS's battery cluster terminal during actual use.

[0003] Currently, traditional methods for simulating BMS cluster current rely on the energy consumption characteristics of passive resistive loads. They utilize Ohm's law to simulate the current at the BMS cluster terminals, essentially simulating discharge conditions through the energy consumed by the resistors and charging conditions through an external power supply. However, because the resistive load is a passive component, manual physical wiring replacement is required to switch between charging and discharging modes and simulate the direction of the current (from charging to discharging, and from discharging to charging). This manual wiring replacement is time-consuming and results in slow current response, leading to low testing efficiency. Utility Model Content

[0004] This application provides a current simulation device and a hardware-in-the-loop testing device for energy storage systems to solve the problem of low testing efficiency caused by the time-consuming process of manually changing wiring to switch the current direction and the slow current response speed in the prior art.

[0005] In a first aspect, embodiments of this application provide a current simulation device, including: an adjustable DC voltage source and a current direction switching circuit; The positive terminal of the adjustable DC voltage source is connected to the positive terminal of the battery cluster of the battery management system through the current direction switching circuit, and the negative terminal of the voltage output is connected to the negative terminal of the battery cluster through the current direction switching circuit. Alternatively, the positive terminal of the adjustable DC voltage source is connected to the negative terminal of the battery cluster via the current direction switching circuit, and the negative terminal of the voltage output is connected to the positive terminal of the battery cluster via the current direction switching circuit.

[0006] In one possible implementation, the current direction switching circuit includes two sets of contact systems; each set of contact systems includes a common terminal, a normally open terminal, and a normally closed terminal, and can be connected to the normally open terminal or the normally closed terminal by a control action. The positive terminal of the adjustable DC voltage source is connected to the positive or negative terminal of the battery cluster via a set of contact systems, and the negative terminal is connected to the positive or negative terminal of the battery cluster via another set of contact systems. Alternatively, the positive terminal of the battery cluster is connected to the positive or negative voltage output terminal of the adjustable DC voltage source via a set of contact systems, and the negative terminal is connected to the positive or negative voltage output terminal of the adjustable DC voltage source via another set of contact systems.

[0007] In one possible implementation, the current direction switching circuit includes a first single-pole double-throw relay and a second single-pole double-throw relay; the common terminal, normally open terminal, and normally closed terminal of the first single-pole double-throw relay and the second single-pole double-throw relay constitute the two sets of contact systems; The common terminal of the first single-pole double-throw relay is connected to the positive terminal of the voltage output, the normally open terminal is connected to the positive terminal of the battery cluster, and the normally closed terminal is connected to the negative terminal of the battery cluster. The common terminal of the second single-pole double-throw relay is connected to the negative terminal of the voltage output, the normally open terminal is connected to the positive terminal of the battery cluster, and the normally closed terminal is connected to the negative terminal of the battery cluster.

[0008] In one possible implementation, the current direction switching circuit includes a first single-pole double-throw relay and a second single-pole double-throw relay; the common terminal, normally open terminal, and normally closed terminal of the first single-pole double-throw relay and the second single-pole double-throw relay constitute the two sets of contact systems; The common terminal of the first single-pole double-throw relay is connected to the positive terminal of the battery cluster, the normally open terminal is connected to the positive terminal of the voltage output, and the normally closed terminal is connected to the negative terminal of the voltage output. The common terminal of the second single-pole double-throw relay is connected to the negative terminal of the battery cluster, the normally open terminal is connected to the positive terminal of the voltage output, and the normally closed terminal is connected to the negative terminal of the voltage output.

[0009] In one possible implementation, the current simulation device further includes a controller electrically connected to the control terminals of the first single-pole double-throw relay and the second single-pole double-throw relay, respectively.

[0010] In one possible implementation, the current direction switching circuit includes a double-pole double-throw relay; the two common terminals, two normally open terminals, and two normally closed terminals of the double-pole double-throw relay constitute the two sets of contact systems. The first common terminal of the double-pole double-throw relay is connected to the positive terminal of the voltage output, the first normally open terminal is connected to the positive terminal of the battery cluster, and the first normally closed terminal is connected to the negative terminal of the battery cluster. The second common terminal of the double-pole double-throw relay is connected to the negative terminal of the voltage output, the second normally open terminal is connected to the negative terminal of the battery cluster, and the second normally closed terminal is connected to the positive terminal of the battery cluster.

[0011] In one possible implementation, the current direction switching circuit includes a double-pole double-throw relay; the two common terminals, two normally open terminals, and two normally closed terminals of the double-pole double-throw relay constitute the two sets of contact systems. The first common terminal of the double-pole double-throw relay is connected to the positive terminal of the battery cluster, the first normally open terminal is connected to the positive terminal of the voltage output, and the first normally closed terminal is connected to the negative terminal of the voltage output. The second common terminal of the double-pole double-throw relay is connected to the negative terminal of the battery cluster, the second normally open terminal is connected to the negative terminal of the voltage output, and the second normally closed terminal is connected to the positive terminal of the voltage output.

[0012] In one possible implementation, the current simulation device further includes a controller electrically connected to the control terminal of the double-pole double-throw relay.

[0013] In one possible implementation, the adjustable DC voltage source includes a communication interface and is connected to a controller via the communication interface.

[0014] Secondly, embodiments of this application provide a hardware-in-the-loop testing device for an energy storage system, comprising: a current simulation device as described in any of the first aspects of this application and a battery management system under test; the battery management system under test is used to perform battery management on the energy storage batteries of the energy storage system.

[0015] This application provides a current simulation device, comprising an adjustable DC voltage source and a current direction switching circuit. The current direction switching circuit automatically controls the current direction, switching the current flow path to the BMS battery cluster terminal to simulate the charging and discharging current direction. When the positive terminal of the adjustable DC voltage source is connected to the positive terminal of the battery cluster terminal of the battery management system through the current direction switching circuit, and the negative terminal is connected to the negative terminal of the battery cluster terminal through the same circuit, current flows from the positive terminal of the adjustable DC voltage source into the positive terminal of the BMS battery cluster terminal, forming a charging circuit. The circuit simulates the charging current direction of a battery cluster in a real-world scenario. When the positive terminal of the adjustable DC voltage source is connected to the negative terminal of the battery cluster via a current direction switching circuit, and the negative terminal is connected to the positive terminal of the battery cluster via the same circuit, current flows from the negative terminal of the BMS battery cluster, forming a discharge loop. This simulates the current direction of the battery cluster discharging to the user load in a real-world scenario, meeting the automated charging and discharging requirements of BMS testing. The current direction can be switched without manual physical wiring changes. The electronic control of the current direction switching circuit enables automated switching, improving current response speed and significantly increasing the efficiency of BMS current simulation, thereby improving testing efficiency. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating an application scenario of the battery management system provided in this application embodiment; Figure 2 This is a schematic diagram of the structure of a current simulation device provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a current simulation device provided in another embodiment of this application; Figure 4 This is a schematic diagram of the current simulation device structure provided in another embodiment of this application; Figure 5 This is a schematic diagram of the structure of a current simulation device provided in another embodiment of this application; Figure 6 This is a schematic diagram of the structure of a current simulation device provided in another embodiment of this application; Figure 7 This is a schematic diagram of the current simulation device structure provided in another embodiment of this application; Figure 8 This is a schematic diagram of the structure of a current simulation device provided in another embodiment of this application. Detailed Implementation

[0017] To enable those skilled in the art to better understand this solution, the technical solutions in the embodiments of this solution will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this solution, not all of them. Based on the embodiments of this solution, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this solution.

[0018] The term "comprising" and any other variations thereof in the specification, claims, and accompanying drawings of this invention mean "including but not limited to," and are intended to cover a non-exclusive inclusion, not limited to the examples listed herein. Furthermore, the terms "first" and "second," etc., are used to distinguish different objects, not to describe a specific order.

[0019] Currently, traditional methods for simulating BMS cluster current are based on the energy consumption characteristics of passive resistive loads. They utilize Ohm's law to simulate the current at the BMS cluster, essentially simulating discharge conditions by consuming electrical energy through resistors and charging conditions through an external power supply. Simulating discharge current: A fixed or adjustable resistance load is directly connected to the positive and negative terminals of the BMS battery cluster. The electrical energy output from the BMS battery cluster is converted into heat energy and dissipated through the resistor. Adjusting the resistance value changes the current in the circuit (the smaller the resistance, the larger the discharge current), thus simulating different discharge intensities. Simulating charging current: An additional DC power supply is required. The positive terminal of the power supply is connected to the positive terminal of the BMS battery cluster, and the negative terminal is connected to the resistive load, allowing current to flow from the power supply into the BMS battery cluster (simulating external charging). The charging current is controlled by adjusting the power supply output voltage or the resistance value. However, since the resistive load is a passive component, manual physical replacement of the wiring is required to switch between charging and discharging modes and simulate the switching of current direction (charging to discharging, discharging to charging). For example, when switching from discharging to charging, the connection between the BMS battery cluster terminal and the resistor must be disconnected first, and the original wiring removed; then the DC power supply and the resistor must be reconnected, and the power supply polarity adjusted so that the current flows into the positive terminal of the BMS battery cluster terminal; conversely, when switching to discharging mode, the DC power supply must be removed and the resistor reconnected. The entire process relies on manual operation, and manual wiring replacement is time-consuming, resulting in low testing efficiency. Furthermore, the resistance value adjustment requires mechanical operation (such as manual adjustment with a sliding rheostat) or manual setting, lacking electronic rapid adjustment capability, resulting in a long response time. It cannot simulate the dynamic current changes during real battery use (such as rapid charging and discharging), and can only simulate stable static current, which cannot cover the dynamic test scenarios required by the BMS (such as instantaneous short circuits and high-frequency charge and discharge cycles), leading to inaccurate test results.

[0020] Battery Management System (BMS) in practical applications, such as Figure 1As shown, multiple battery cells form a battery pack (multiple battery packs form a battery cluster). The positive and negative terminals of the battery pack are connected to the user load and the charging equipment, respectively. The battery pack provides electrical energy to the user load (discharging process). When the battery pack's charge is low, the charging equipment charges the battery pack (charging process). When the BMS monitors the actual operating status of the battery pack, it collects the charging current I through a Hall current sensor. 充 and discharge current I 放 The Hall current sensor converts the collected current signal into a corresponding voltage signal V (the conversion ratio is determined by the Hall coefficient) and sends it to the BMS's analog-to-digital converter (ADC). The ADC module converts the analog voltage signal into a digital signal, and the BMS reconstructs the current value based on the digital signal, thereby determining whether the charging and discharging process of the battery pack is normal.

[0021] Practical application scenarios based on BMS (such as) Figure 1 To address the shortcomings of existing technologies, this application proposes the following technical concept: A current simulation device is constructed using an adjustable DC voltage source and a current direction switching circuit. The output of the adjustable DC voltage source directly simulates the voltage signal (V) output by the Hall sensor in a real-world BMS application scenario. Then, the current charging and discharging simulation is achieved using the current direction switching circuit. The current direction can be automatically controlled by the current direction switching circuit. When the positive terminal of the adjustable DC voltage source's voltage output is connected to the positive terminal of the battery cluster in the battery management system through the current direction switching circuit, and the negative terminal is connected to the negative terminal of the battery cluster through the current direction switching circuit, current flows from the positive terminal of the adjustable DC voltage source into the positive terminal of the BMS battery cluster, forming a charging circuit and simulating the charging current direction of the battery cluster in a real-world scenario. When the positive terminal of the adjustable DC voltage source's voltage output... When the negative terminal of the voltage output is connected to the negative terminal of the battery cluster via the current direction switching circuit, and the negative terminal is connected to the positive terminal of the battery cluster via the same circuit, current flows into the BMS battery cluster from the negative terminal, forming a discharge loop. This simulates the current direction of the battery cluster discharging to the user load in a real-world scenario, meeting the automated charging and discharging requirements of BMS testing. The current direction can be switched without manual physical wiring changes, solving the problem of traditional resistive load methods that require manual wiring changes to switch charging and discharging directions. Automated switching is achieved through electronic control of the current direction switching circuit. Furthermore, only the output voltage of the adjustable DC voltage source needs to be adjusted to simulate different charging and discharging current conditions, eliminating the need for manual resistor adjustments to change the current magnitude. This improves the current response speed and significantly enhances the efficiency of BMS current simulation, thereby increasing testing efficiency and the accuracy of test results.

[0022] The implementation of this application will be described in detail below with reference to the specific accompanying drawings: Figure 2This is a schematic diagram of the structure of a current simulation device provided in an embodiment of this application.

[0023] like Figure 2 As shown, the current simulation device provided in this embodiment includes: an adjustable DC voltage source and a current direction switching circuit; the positive voltage output terminal (V+) of the adjustable DC voltage source is connected to the positive terminal (+) of the battery cluster terminal of the battery management system through the current direction switching circuit, and the negative voltage output terminal (V-) is connected to the negative terminal (-) of the battery cluster terminal through the current direction switching circuit; or, the positive voltage output terminal (V+) of the adjustable DC voltage source is connected to the negative terminal (-) of the battery cluster terminal through the current direction switching circuit, and the negative voltage output terminal (V-) is connected to the positive terminal (+) of the battery cluster terminal through the current direction switching circuit.

[0024] In this embodiment, as Figure 2 As shown, when simulating charging conditions, the current direction switching circuit switches the voltage output positive terminal V+ of the adjustable DC voltage source to the positive terminal of the BMS battery cluster and the voltage output negative terminal V- to the negative terminal of the battery cluster (e.g., ...). Figure 2 (The red dashed line in the diagram indicates a conductive connection). Current flows from the adjustable DC voltage source V+ → the positive terminal of the BMS battery cluster → the internal circuit of the BMS → the negative terminal of the BMS battery cluster → the adjustable DC voltage source V-, forming a charging loop to simulate the scenario of charging current flowing into the battery cluster. When simulating discharge conditions, the current direction switching circuit switches the connection between the positive terminal V+ of the adjustable DC voltage source and the negative terminal of the BMS battery cluster, and between V- and the positive terminal of the battery cluster (e.g., ...). Figure 2 (The blue dashed line in the diagram indicates a conductive connection). Current flows from the adjustable DC voltage source V+ → negative terminal of the BMS battery cluster → internal circuit of the BMS → positive terminal of the BMS battery cluster → adjustable DC voltage source V+, forming a discharge loop to simulate the scenario where discharge current flows out of the battery cluster.

[0025] In this embodiment, the adjustable DC voltage source has an RS485 communication interface. The RS485 interface is connected to the controller, and the output voltage of the adjustable DC voltage source can be remotely adjusted through the RS485 interface, thereby simulating the different voltage signals output by the Hall current sensor according to different charging and discharging currents in the actual scenario, and realizing intelligent remote control.

[0026] It should be noted that the embodiment provided in this example Figure 2 In the diagram, the red and blue dashed lines only schematically represent two circuit connection methods for the current direction switching circuit. When the path shown by the red dashed line is conducting, the path shown by the blue dashed line is in an open state; conversely, when the path shown by the blue dashed line is conducting, the path shown by the red dashed line is in an open state.

[0027] In one possible implementation, the current direction switching circuit includes two sets of contact systems; each set of contact systems includes a common terminal, a normally open terminal, and a normally closed terminal, and can be connected to the normally open or normally closed terminal by a control action; the positive terminal of the adjustable DC voltage source is connected to the positive or negative terminal of the battery cluster through one set of contact systems, and the negative terminal of the battery cluster is connected to the positive or negative terminal of the battery cluster through another set of contact systems; or, the positive terminal of the battery cluster is connected to the positive or negative terminal of the adjustable DC voltage source through one set of contact systems, and the negative terminal is connected to the positive or negative terminal of the adjustable DC voltage source through another set of contact systems.

[0028] For example, the common terminal can be controlled to conduct with the normally open or normally closed terminal by the coil. The common terminal is the hub of circuit switching. When the coil is not energized, the common terminal is disconnected from the normally open terminal and conducts with the normally closed terminal. When the coil is energized, the common terminal conducts with the normally open terminal and is disconnected from the normally closed terminal.

[0029] In this embodiment, the two sets of contact systems can be two sets of C-type contacts, and the common terminal of each set of C-type contacts can be connected to the normally open or normally closed terminal through coil control.

[0030] In this embodiment, the connection between the positive / negative terminals of the adjustable DC voltage source and the positive / negative terminals of the battery cluster is independently controlled by two sets of contact systems (each set includes a common terminal, a normally open terminal, and a normally closed terminal). Furthermore, the common terminal of each set of contacts can be selectively connected to either the normally open terminal or the normally closed terminal, thereby achieving switching between two independent circuits. This eliminates the need for complex power conversion circuits to achieve current direction switching, reducing the hardware complexity and failure rate of the device.

[0031] The following is combined with Figures 3-8 The connection method of the two sets of contact systems and the control switching logic of the circuit direction in the current direction switching circuit are described.

[0032] In one possible implementation, the current direction switching circuit includes two single-pole double-throw (SPDT) relays, such as a first SPDT relay (SPDT1) and a second SPDT relay (SPDT2); the common terminal (COM), normally open terminal (NO), and normally closed terminal (NC) of the first SPDT relay and the second SPDT relay constitute the two sets of contact systems.

[0033] It should be noted that when two single-pole double-throw relays form a current direction switching circuit, there are two connection methods.

[0034] In one possible implementation, such as Figure 3As shown, the common terminal COM of the first single-pole double-throw relay (SPDT1) is connected to the positive terminal (V+) of the voltage output, the normally open terminal NO is connected to the positive terminal (+) of the battery cluster, and the normally closed terminal NC is connected to the negative terminal (-) of the battery cluster; the common terminal COM of the second single-pole double-throw relay (SPDT2) is connected to the negative terminal (V-) of the voltage output, the normally open terminal NO is connected to the positive terminal (+) of the battery cluster, and the normally closed terminal NC is connected to the negative terminal (-) of the battery cluster.

[0035] In one possible implementation, such as Figure 4 As shown, the common terminal COM of the first single-pole double-throw relay (SPDT1) is connected to the positive terminal of the battery cluster, the normally open terminal NO is connected to the positive terminal (V+) of the voltage output, and the normally closed terminal NC is connected to the negative terminal (V-) of the voltage output; the common terminal COM of the second single-pole double-throw relay (SPDT2) is connected to the negative terminal of the battery cluster, the normally open terminal NO is connected to the positive terminal (V+) of the voltage output, and the normally closed terminal is connected to the negative terminal (V-) of the voltage output.

[0036] In one possible embodiment, such as Figure 5 As shown, the temperature simulation device also includes a controller, which is electrically connected to the control terminals of the first single-pole double-throw relay and the second single-pole double-throw relay, respectively.

[0037] In this embodiment, as Figure 3 , Figure 4 and Figure 5 As shown, when simulating charging current is required, the controller sends a first electrical signal to the control terminal of the first single-pole double-throw relay SPDT1, energizing the coil of SPDT1 and connecting the common terminal COM and normally open terminal NO of SPDT1. Simultaneously, the controller sends a second electrical signal to the control terminal of the second single-pole double-throw relay SPDT2, de-energizing the coil of SPDT2 and connecting the common terminal COM and normally closed terminal NC. This connects the V+ of the adjustable DC voltage source to the positive terminal of the BMS cluster and the V- to the negative terminal of the BMS cluster, allowing current to flow from the adjustable DC voltage source V+ to the normally closed terminal of the first single-pole double-throw relay. The charging circuit is formed by connecting the BMS cluster positive terminal to the BMS internal circuit, then to the adjustable DC voltage source V-. When simulating discharge current, the controller controls the common terminal COM of SPDT1 to conduct with the normally closed terminal NC, and simultaneously controls the common terminal COM of SPDT2 to conduct with the normally open terminal NO. This connects V+ to the BMS cluster negative terminal and V- to the BMS cluster positive terminal. The current flows from the adjustable DC voltage source V+ → the normally open terminal of the second single-pole double-throw relay → the BMS cluster negative terminal → the BMS internal circuit → the BMS cluster positive terminal → the adjustable DC voltage source V-, forming a discharge circuit.

[0038] It should be noted that the two single-pole double-throw relays mentioned above can be type C relays.

[0039] In one possible embodiment, the adjustable DC voltage source is connected to the controller via an RS485 communication interface, and the voltage signal output by the adjustable DC voltage source is adjusted.

[0040] In this embodiment, a current direction switching circuit is formed by two single-pole double-throw switches, which is simple and convenient to control. The current switching direction can be quickly controlled by the controller. With the help of an adjustable DC voltage source to output different voltage signals, the current response speed is improved. It can simulate the dynamic current changes (such as rapid charging and rapid discharging) during the actual use of a battery, which greatly improves the efficiency of BMS current simulation, thereby improving the testing efficiency and the accuracy of the test results.

[0041] In another possible implementation, such as Figures 6-8 As shown, the current direction switching circuit includes a double-pole double-throw relay; the two common terminals, two normally open terminals, and two normally closed terminals of the double-pole double-throw relay constitute the two sets of contact systems.

[0042] In one possible implementation, such as Figure 6 As shown, the first common terminal (COM1) of the double-pole double-throw relay is connected to the positive voltage output terminal V+, the first normally open terminal (NO1) is connected to the positive terminal of the battery cluster, and the first normally closed terminal (NC1) is connected to the negative terminal of the battery cluster; the second common terminal (COM2) of the double-pole double-throw relay is connected to the negative voltage output terminal V-, the second normally open terminal (NO2) is connected to the negative terminal of the battery cluster, and the second normally closed terminal (NC2) is connected to the positive terminal of the battery cluster.

[0043] In one possible implementation, such as Figure 7 As shown, the first common terminal (COM1) of the double-pole double-throw relay is connected to the positive terminal of the battery cluster, the first normally open terminal (NO1) is connected to the positive voltage output terminal V+, and the first normally closed terminal (NC1) is connected to the negative voltage output terminal V-. The second common terminal (COM2) of the double-pole double-throw relay is connected to the negative terminal of the battery cluster, the second normally open terminal (NO2) is connected to the negative voltage output terminal V-, and the second normally closed terminal (NC2) is connected to the positive voltage output terminal V+.

[0044] It should be noted that a double-pole double-throw relay contains two completely independent C-type contacts. Each group of contacts has three ports: COM, NO, and NC, and is synchronously driven by the same coil. The contact part of a double-pole double-throw relay can be disassembled into two groups: COM1-NO1-NC1 and COM2-NO2-NC2. When the coil is energized, both groups of contacts will switch from NC to NO simultaneously, and when de-energized, they will switch from NO to NC simultaneously.

[0045] In one possible implementation, such as Figures 5-8 As shown, the adjustable DC voltage source includes a communication interface (RS485) and is connected to the controller through the communication interface.

[0046] In one possible implementation, such as Figure 8 As shown, the control terminal of the double-pole double-throw relay is electrically connected to the controller. When it is necessary to simulate the charging current, the controller controls the coil of the double-pole double-throw relay to be energized, and the two sets of contacts act simultaneously. COM1 switches to NO1 to conduct, and COM2 switches to NO2 to conduct. When it is necessary to simulate the discharging current, COM1 switches to NC1, and at the same time, COM2 switches to NC2.

[0047] In this embodiment, the two sets of contact systems of the double-pole double-throw relay can be linked by a unified control signal to ensure the timing matching of "disconnecting the original path" and "connecting the new path" when the current direction is switched, avoid current interruption or overshoot during the switching process, ensure the continuity of the simulated current, and thus further ensure the accuracy of the current simulation.

[0048] This application also provides a hardware-in-the-loop testing device for an energy storage system, including: as shown in 2- Figure 8 The current simulation device and the battery management system under test shown in any one of the embodiments. The energy storage system includes multiple battery clusters, each battery cluster being formed by connecting multiple energy storage battery packs. The battery management system under test is used to manage the entire energy storage system, or the battery clusters, or each energy storage battery, to monitor, control, and protect the operating status of each energy storage battery.

[0049] In this embodiment, the connection method of the battery management system under test is referenced. Figures 2-8 In the actual test scenario, the BMS under test receives the voltage signal (simulating charging and discharging current) output by the adjustable DC voltage source, then converts the voltage signal into a digital signal, and restores the corresponding current value based on the digital signal, thereby determining whether the current protection function of the BMS under test is normal.

[0050] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0051] Furthermore, the features of the embodiments shown in the accompanying drawings or the various embodiments mentioned in this specification should not be construed as independent embodiments. Rather, each feature described in one example of an embodiment can be combined with one or more other desired features from other embodiments to produce other embodiments not described in words or with reference to the accompanying drawings.

[0052] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A current simulation device, characterized in that, include: Adjustable DC voltage source and current direction switching circuit; The positive terminal of the adjustable DC voltage source is connected to the positive terminal of the battery cluster of the battery management system through the current direction switching circuit, and the negative terminal of the voltage output is connected to the negative terminal of the battery cluster through the current direction switching circuit. Alternatively, the positive terminal of the adjustable DC voltage source is connected to the negative terminal of the battery cluster via the current direction switching circuit, and the negative terminal of the voltage output is connected to the positive terminal of the battery cluster via the current direction switching circuit.

2. The current simulation device as described in claim 1, characterized in that, The current direction switching circuit includes two sets of contact systems; each set of contact systems includes a common terminal, a normally open terminal, and a normally closed terminal, and can be controlled to make the common terminal conduct with the normally open terminal or the normally closed terminal. The positive terminal of the adjustable DC voltage source is connected to the positive or negative terminal of the battery cluster via a set of contact systems, and the negative terminal is connected to the positive or negative terminal of the battery cluster via another set of contact systems. Alternatively, the positive terminal of the battery cluster is connected to the positive or negative voltage output terminal of the adjustable DC voltage source via a set of contact systems, and the negative terminal is connected to the positive or negative voltage output terminal of the adjustable DC voltage source via another set of contact systems.

3. The current simulation device as described in claim 2, characterized in that, The current direction switching circuit includes a first single-pole double-throw relay and a second single-pole double-throw relay; the common terminal, normally open terminal and normally closed terminal of the first single-pole double-throw relay and the second single-pole double-throw relay constitute the two sets of contact systems; The common terminal of the first single-pole double-throw relay is connected to the positive terminal of the voltage output, the normally open terminal is connected to the positive terminal of the battery cluster, and the normally closed terminal is connected to the negative terminal of the battery cluster. The common terminal of the second single-pole double-throw relay is connected to the negative terminal of the voltage output, the normally open terminal is connected to the positive terminal of the battery cluster, and the normally closed terminal is connected to the negative terminal of the battery cluster.

4. The current simulation device as described in claim 2, characterized in that, The current direction switching circuit includes a first single-pole double-throw relay and a second single-pole double-throw relay; the common terminal, normally open terminal and normally closed terminal of the first single-pole double-throw relay and the second single-pole double-throw relay constitute the two sets of contact systems; The common terminal of the first single-pole double-throw relay is connected to the positive terminal of the battery cluster, the normally open terminal is connected to the positive terminal of the voltage output, and the normally closed terminal is connected to the negative terminal of the voltage output. The common terminal of the second single-pole double-throw relay is connected to the negative terminal of the battery cluster, the normally open terminal is connected to the positive terminal of the voltage output, and the normally closed terminal is connected to the negative terminal of the voltage output.

5. The current simulation device as described in claim 3 or 4, characterized in that, Also includes: The controller is electrically connected to the control terminals of the first single-pole double-throw relay and the second single-pole double-throw relay, respectively.

6. The current simulation device as described in claim 2, characterized in that, The current direction switching circuit includes a double-pole double-throw relay; the two common terminals, two normally open terminals, and two normally closed terminals of the double-pole double-throw relay constitute the two sets of contact systems; The first common terminal of the double-pole double-throw relay is connected to the positive terminal of the voltage output, the first normally open terminal is connected to the positive terminal of the battery cluster, and the first normally closed terminal is connected to the negative terminal of the battery cluster. The second common terminal of the double-pole double-throw relay is connected to the negative terminal of the voltage output, the second normally open terminal is connected to the negative terminal of the battery cluster, and the second normally closed terminal is connected to the positive terminal of the battery cluster.

7. The current simulation device as described in claim 2, characterized in that, The current direction switching circuit includes a double-pole double-throw relay; the two common terminals, two normally open terminals, and two normally closed terminals of the double-pole double-throw relay constitute the two sets of contact systems; The first common terminal of the double-pole double-throw relay is connected to the positive terminal of the battery cluster, the first normally open terminal is connected to the positive terminal of the voltage output, and the first normally closed terminal is connected to the negative terminal of the voltage output. The second common terminal of the double-pole double-throw relay is connected to the negative terminal of the battery cluster, the second normally open terminal is connected to the negative terminal of the voltage output, and the second normally closed terminal is connected to the positive terminal of the voltage output.

8. The current simulation device as described in claim 6 or 7, characterized in that, Also includes: The controller is electrically connected to the control terminal of the double-pole double-throw relay.

9. The current simulation device according to any one of claims 1 to 8, characterized in that, The adjustable DC voltage source includes a communication interface and is connected to the controller through the communication interface.

10. A hardware-in-the-loop testing device for an energy storage system, characterized in that, include: The current simulation device and the battery management system under test as described in any one of claims 1 to 9; The battery management system under test is used to manage the energy storage batteries of the energy storage system.

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