Power test load circuit of energy storage system and power test system

Abstract

The utility model belongs to the technical field of energy storage system power test, and particularly relates to a power test load circuit of an energy storage system and a power test system, the load circuit comprises a short circuit switch module and K load units connected in series, and K is greater than or equal to 2; the high-voltage ends of the serially connected load units are connected with the anode interface, one end of the short-circuit switch module is connected with the cathode interface, and the other end is selectively conducted and connected with the low-voltage ends of the load units; the anode interface and the cathode interface are respectively used for connecting the anode and the cathode of the energy storage system; each load unit comprises a circuit break switch module and a load branch circuit or at least two load branch circuits connected in parallel, each load branch circuit is connected with a load resistor in series, and the circuit break switch module is used for disconnecting the load resistor from the load unit when the load resistor does not need to be put in; load circuits suitable for different voltages and power levels can be formed, the applicability is high, different load circuits do not need to be designed for different voltages and power levels, the cost is low, and the detection efficiency is high.

Description

Technical Field

[0001] The utility model belongs to the technical field of power testing of energy storage systems, and in particular relates to a power testing load circuit and a power testing system of an energy storage system. Background Art

[0002] At present, under the guidance of national policies, electrochemical energy storage systems are widely used, and the power of energy storage systems is of various levels. Therefore, in the prior art, when performing power tests on energy storage systems of different power levels, it is necessary to design a set of test loads for each power level of energy storage system separately, which is very costly and has low detection efficiency. Utility Model Content

[0003] The utility model aims to provide a power test load circuit and a power test system for an energy storage system, so as to solve the technical problem that when performing power detection on energy storage systems of different power levels, it is necessary to design and replace the test load, resulting in high detection cost and low efficiency.

[0004] In order to solve the above technical problems, the utility model provides a power test load circuit of an energy storage system, comprising a short-circuit switch module and K load units connected in series, K≥2;

[0005] The high-voltage end of the load units connected in series is connected to the positive electrode interface, one end of the short-circuit switch module is connected to the negative electrode interface, and the other end is connected to the low-voltage end of each load unit; or, the low-voltage end of the load units connected in series is connected to the negative electrode interface, one end of the short-circuit switch module is connected to the positive electrode interface, and the other end is connected to the high-voltage end of each load unit; the positive and negative electrode interfaces are interfaces for connecting the positive and negative electrodes of the energy storage system respectively;

[0006] Each load unit includes a circuit breaker module and a load branch or at least two load branches connected in parallel. A load resistor is connected in series on each load branch. The circuit breaker module is used to disconnect the load resistor from the load unit when it is not needed.

[0007] Furthermore, the short-circuit switch module includes K short-circuit control switches, and one end of each short-circuit control switch is connected to the negative electrode interface, and the other end is respectively connected to the low-voltage end of each load unit, and each short-circuit control switch is selectively turned on.

[0008] Furthermore, the short-circuit switch module includes K short-circuit control switches, and one end of each short-circuit control switch is connected to the positive electrode interface, and the other end is connected to the high-voltage end of each load unit, and each short-circuit control switch is selectively turned on.

[0009] Furthermore, the circuit breaker switch module includes the same number of circuit breaker control switches as the number of load branches, and each load branch is connected in series with a circuit breaker control switch.

[0010] Furthermore, the load circuit also includes a current detection module for detecting the current of the load unit in a working state.

[0011] Furthermore, the load circuit also includes a temperature acquisition module for acquiring the temperature of the load resistor. When the temperature of a load resistor is higher than its safe temperature, the load resistor is disconnected from the load unit through the circuit breaker switch module.

[0012] Furthermore, the number and resistance values ​​of the load resistors in all load branches of the same load unit are equal.

[0013] Furthermore, each short-circuit control switch is a contactor switch.

[0014] The utility model is an improved invention, and its beneficial effects are as follows: the load circuit of the utility model includes multiple load units and a circuit breaker module, and the input status of the load unit is controlled by the short-circuit switch module, and the corresponding load unit is input according to the power and voltage status of the energy storage system to be tested, and each load unit is composed of a load branch or at least two load branches in parallel, and each load branch is connected in series with a load resistor controlled by the short-circuit switch module. The number of load units and load resistors connected to the work is adjusted by the short-circuit switch module and the circuit breaker module, and a load circuit suitable for different voltages and power levels can be formed, which has strong applicability, does not need to design different load circuits for different voltages and power levels, has low cost, and has high detection efficiency.

[0015] In order to solve the above technical problems, the utility model also provides a power test system of an energy storage system, including a load circuit and a control system; the load circuit includes a short-circuit switch module and a plurality of load units connected in series;

[0016] The high-voltage end of the series-connected load unit is connected to the positive electrode interface, one end of the short-circuit switch module is connected to the negative electrode interface, and the other end is connected to the low-voltage end of each load unit; or, the low-voltage end of the series-connected load unit is connected to the negative electrode interface, one end of the short-circuit switch module is connected to the positive electrode interface, and the other end is connected to the high-voltage end of each load unit; the positive and negative electrode interfaces are used to connect the positive and negative electrodes of the energy storage system respectively;

[0017] Each load unit includes a circuit breaker module and a load branch or multiple load branches connected in parallel, each load branch is connected in series with a load resistor, and the circuit breaker module is used to disconnect the load resistor from the load unit when it is not needed;

[0018] The control system is used to calculate the load circuit power and control the short-circuit switch module and the disconnect switch module.

[0019] Furthermore, the control system includes a host computer and a BMS main control module connected thereto, wherein the BMS main control module includes a function for obtaining voltage and current information of the load circuit and sending the information to the host computer, and is also used for controlling the circuit breaker module and the short-circuit switch module according to the command of the host computer;

[0020] The host computer is used to calculate the load circuit power according to the voltage and current information of the load circuit, and is also used to send control instructions of the short-circuit switch module and the circuit-breaking switch module to the BMS main control module.

[0021] Furthermore, the control system also includes a load resistor temperature acquisition module, which is connected to the host computer and sends temperature information of each load resistor to the host computer.

[0022] The beneficial effects are as follows: the load circuit of the utility model includes multiple load units and a circuit breaker module, and the input status of the load unit is controlled by the short-circuit switch module, and the corresponding load unit is input according to the power and voltage status of the energy storage system to be tested, and each load unit is composed of a load branch or at least two load branches in parallel, and each load branch is connected in series with a load resistor controlled by the short-circuit switch module. The number of load units and load resistors connected to the work is adjusted by the short-circuit switch module and the circuit breaker module, and a load circuit suitable for different voltages and power levels can be formed, which has strong applicability, does not need to design different load circuits for different voltages and power levels, has low cost, and has high detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a load circuit principle diagram of a load circuit embodiment of the utility model;

[0024] Figure 2 is a load circuit schematic diagram of other implementations of the load circuit embodiment of the utility model;

[0025] Figure 3 It is a schematic diagram of a low-voltage control system of an embodiment of a test system of the utility model. DETAILED DESCRIPTION

[0026] The utility model discloses a power test load circuit and a power test system for an energy storage system, comprising a short-circuit switch module and a plurality of load units connected in series; the high-voltage end of the load units connected in series is connected to the positive electrode interface, one end of the short-circuit switch module is connected to the negative electrode interface, and the other end is selectively connected to the low-voltage end of each load unit; or, the low-voltage end of the load units connected in series is connected to the negative electrode interface, one end of the short-circuit switch module is connected to the positive electrode interface, and the other end is selectively connected to the high-voltage end of each load unit; the positive and negative electrode interfaces are interfaces for connecting the positive and negative electrodes of the energy storage system, respectively; each load unit comprises a disconnect switch module, and a load branch or at least two load branches connected in parallel, each load branch is connected in series with a load resistor, and the disconnect switch module is used to disconnect the load resistor from the load unit when it is not needed.

[0027] By adjusting the number of load units and load resistors connected to the load circuit through the short-circuit switch module and the circuit breaker module, a load circuit suitable for different voltages and power levels can be formed. It has strong applicability and does not need to design different load circuits for different voltages and power levels. It has low cost and high detection efficiency. Two or more load units connected in series can disperse the voltage of the energy storage system to the two sections of each load unit, reduce the voltage of each load unit, and make the load circuit safer.

[0028] Load circuit example:

[0029] The schematic diagram of the power test load circuit of this embodiment is as follows: Figure 1 As shown, it includes a load circuit, which is connected in series with n load units, two contactor switches KM1 and KMn+1, an isolating switch QS, a fuse FU and a current sensor HALL, which are used to connect the interfaces of the positive and negative poles of the energy storage system to be tested (not shown in the figure). The isolating switch and the fuse are used to short-circuit protect the system. Each load unit includes one or more parallel load branches, and each load branch is connected in series with a load resistor and a circuit breaker control switch for controlling its input and exit. A short-circuit control switch KM2-KMn is connected in parallel between the low-voltage end of each load unit and the interface for connecting the negative pole of the energy storage system to be tested. The short-circuit control switch KM2-KMn is used to short-circuit the corresponding load unit. Specifically, when KM2 is closed, load unit 2-load unit n is short-circuited and does not participate in the work. When KM3 is closed, load unit 3-load unit n is short-circuited and does not participate in the work, and so on. As another control method, the short-circuit control switch can also be connected in parallel between the high-voltage end of each load unit and the interface for connecting the positive electrode of the energy storage system to be tested, such as Figure 2 shown.

[0030] The short-circuit control switches KM2-KMn constitute a short-circuit switch module. In this embodiment, a plurality of contactor switches are taken as an example. As another implementation method, it can also be a group of multi-pole multi-throw switches.

[0031] In this embodiment, the load resistor sheet material is a stainless steel resistor sheet from a standard electric heating alloy, the stainless steel resistor sheet raw material is processed into a high-strength bar resistor element, and a plurality of bar resistor elements are connected in series to form a load resistor, which is more cost-effective. As other implementations, the load resistor may also be a load resistor made of other metal thermoelectric alloys.

[0032] The load resistors Rn-1~Rn-n are all equipped with temperature collection points to monitor their temperatures in real time. When the temperature exceeds the safe working temperature, the contactors on their branches can be controlled to isolate them to ensure system safety.

[0033] Through the series and parallel connection between the load unit and the load resistor, a variety of different test schemes can be combined to apply to energy storage systems of different power and voltage levels. 2 / P Calculate the total system resistance, and then calculate the resistance R1 outside the load resistance. The total resistance of the required load resistance is R-R1. According to the total load resistance, decide how much load resistance to invest and select from the following test schemes.

[0034] Energy storage system main circuit power test scheme 1 (n series and 1 parallel): Close the contactors KM1-1, KM2-1...KMn-1 in the load module in sequence, connect the load resistors R1-1, R2-1...Rn-1 in series, then close the contactors KM1, KMn+1, and finally close the isolating switch QS.

[0035] Energy storage system main circuit power test scheme 2 (n series and 2 parallel): Close the contactors KM1-1, KM2-1...KMn-1 in the load module in sequence, and then close the contactors KM1-2, KM2-2...KMn-2 in the load module in sequence, so that the load resistors R1-1, R2-1...Rn-1 and the load resistors R1-2, R2-2...Rn-2 are connected in series and then in parallel; then close the contactors KM1 and KMn+1, and finally close the isolating switch QS.

[0036] By analogy, the energy storage system main circuit power test scheme n (n series n parallel): close the contactors KM1-1, KM2-1...KMn-1 in the load module in sequence, and then close the contactors KM1-2, KM2-2...KMn-2 in the load module in sequence, and then close the contactors KM1-n, KM2-n...KMn-n in the load module in sequence; connect the load resistors R1-1, R2-1...Rn-1, the load resistors R1-2, R2-2...Rn-2, and the load resistors R1-n, R2-n...Rn-n in series and then in parallel; then close the contactors KM1 and KMn+1, and finally close the isolation switch QS.

[0037] Energy storage system main circuit power test solution n+1 (n in parallel and 1 in series): close contactors KM1-1, KM1-2, ... KM1-n in load unit 1 in sequence, connect load resistors R1-1, R1-2, ... R1-n in parallel, then close contactors KM1 and KM2, and finally close isolating switch QS.

[0038] Energy storage system main circuit power test solution n+2 (n in parallel and 2 in series): close contactors KM1-1, KM1-2...KM1-n in load unit 1 and contactors KM2-1, KM2-2...KM2-n in load unit 2 in sequence, so that load resistors R1-1, R1-2...R1-n and load resistors R2-1, R2-2...R2-n are connected in parallel and then in series; then close contactors KM1 and KM3, and finally close isolating switch QS.

[0039] The circuit breaker control switches KM1-1 to KM1-n, KM2-1 to KM2-n and KMn-1 to KMn-n are all circuit breaker switch modules. In this embodiment, multiple contactor switches are taken as an example. As another implementation method, it can also be a group of multi-pole multi-throw switches.

[0040] For ease of explanation and understanding, in this embodiment, the number of load units and the number of load resistors in each load unit are both n. However, in actual use, the number of load resistors in each load unit can be set according to actual needs and does not have to be equal to the number of load units.

[0041] In this embodiment, there is only one load resistor in each load branch. In other embodiments, there may be multiple load resistors in each load branch. In this embodiment, the resistance of each load branch in the same load unit is equal, which can avoid the circulation of the parallel circuit and further ensure the safety of the load circuit. The load resistors in the same load unit are connected in parallel using copper bars or wires. In other embodiments, the resistance of each load resistor can be set according to actual needs.

[0042] Test system example:

[0043] The test system of the energy storage system of the utility model includes a low-voltage control system and a load circuit. The specific structure, principle and beneficial effects of the load circuit have been introduced in detail in the load circuit embodiment, and will not be repeated in this embodiment. The low-voltage control system is used to control the load circuit according to the instructions of the host computer to implement different test schemes.

[0044] The schematic diagram of the low voltage control system is as follows Figure 3 As shown, the low-voltage control system mainly includes: BMS master control module, BMS slave control module, load resistor temperature acquisition module, and host computer.

[0045] The BMS main control module has functions such as voltage acquisition, current acquisition, DO control interface, internal CAN0 communication and external CAN1 communication. The power supply of the BMS main control module is DC24V. The BMS main control module controls the circuit breaker module and the short-circuit switch module through the DO control interface, which are the coils of all contactor switches in this embodiment.

[0046] The host computer communicates with the BMS main control module through CAN0 communication, sends control instructions for all contactors to the BMS main control module, and controls the load circuit to be combined into a load circuit that matches the voltage and power of the energy storage system. During the detection process, the host computer obtains the voltage and current data of the load circuit from the BMS main control module and calculates the power of the load circuit. The specific load circuit power calculation method is the existing technology, and the utility model does not make any improvements.

[0047] The load resistor temperature acquisition module monitors the temperature of each resistor in real time and uploads the temperature information to the host computer through CAN2 communication; when the temperature of a load resistor exceeds its safe operating temperature, the host computer sends an instruction to the BMS main control module to control the circuit breaker control switch corresponding to the load resistor to disconnect, thereby ensuring the safety of the load circuit.

[0048] The host computer receives information sent by the BMS main control module and the load resistor temperature acquisition module at the same time, and displays the system operating parameters; the host computer also has the function of controlling the on and off of the isolation switch, and can cut off the main circuit of the system when a system failure occurs. When the load resistor temperature exceeds its safe working temperature, the load resistor temperature acquisition module sends the information to the host computer, and the host computer sends its information to the BMS main control module at the same time. The BMS main control module disconnects the branch circuit breaker control switch where the alarm load resistor is located through the DO control interface to isolate it and ensure system safety.

[0049] The BMS slave control module has the functions of collecting the voltage, temperature, and communication of the single battery of the energy storage system, and uploading the collected data to the BMS master control module through CAN0 communication.

Claims

1. A power test load circuit of an energy storage system, characterized in that: It includes a short-circuit switch module and K load units connected in series, K≥2; The high-voltage end of the load units connected in series is connected to the positive electrode interface, one end of the short-circuit switch module is connected to the negative electrode interface, and the other end is connected to the low-voltage end of each load unit; or, the low-voltage end of the load units connected in series is connected to the negative electrode interface, one end of the short-circuit switch module is connected to the positive electrode interface, and the other end is connected to the high-voltage end of each load unit; the positive and negative electrode interfaces are interfaces for connecting the positive and negative electrodes of the energy storage system respectively; Each load unit includes a circuit breaker module and a load branch or at least two load branches connected in parallel. A load resistor is connected in series on each load branch. The circuit breaker module is used to disconnect the load resistor from the load unit when it is not needed.

2. The power test load circuit of the energy storage system according to claim 1, characterized in that: The short-circuit switch module includes K short-circuit control switches, and one end of each short-circuit control switch is connected to the negative electrode interface, and the other end is connected to the low-voltage end of each load unit, and each short-circuit control switch is selectively turned on.

3. The power test load circuit of the energy storage system according to claim 1, characterized in that: The short-circuit switch module includes K short-circuit control switches, and one end of each short-circuit control switch is connected to the positive electrode interface, and the other end is respectively connected to the high-voltage end of each load unit, and each short-circuit control switch is selectively turned on.

4. The power test load circuit of the energy storage system according to claim 1, characterized in that: The circuit breaker switch module includes the same number of circuit breaker control switches as the load branches, and each load branch is connected in series with a circuit breaker control switch.

5. The power test load circuit of the energy storage system according to claim 1, characterized in that: The load circuit further comprises a current detection module for detecting the current of the load unit in a working state.

6. The power test load circuit of the energy storage system according to claim 1, characterized in that: The load circuit also includes a temperature acquisition module for acquiring the temperature of the load resistor. When the temperature of a load resistor is higher than its safe temperature, the load resistor is disconnected from the load unit through the circuit breaker switch module.

7. The power test load circuit of the energy storage system according to claim 1, characterized in that: The number and resistance value of load resistors on all load branches in the same load unit are equal.

8. The power test load circuit of the energy storage system according to claim 2 or 3, characterized in that: Each short-circuit control switch is a contactor switch.

9. A power test system for an energy storage system, characterized in that: Including load circuit and control system; The load circuit includes a short-circuit switch module and a plurality of load units connected in series; The high-voltage end of the series-connected load unit is connected to the positive electrode interface, one end of the short-circuit switch module is connected to the negative electrode interface, and the other end is connected to the low-voltage end of each load unit; or, the low-voltage end of the series-connected load unit is connected to the negative electrode interface, one end of the short-circuit switch module is connected to the positive electrode interface, and the other end is connected to the high-voltage end of each load unit; the positive and negative electrode interfaces are used to connect the positive and negative electrodes of the energy storage system respectively; Each load unit includes a circuit breaker module and a load branch or multiple load branches connected in parallel, each load branch is connected in series with a load resistor, and the circuit breaker module is used to disconnect the load resistor from the load unit when it is not needed; The control system is used to calculate the load circuit power and control the short-circuit switch module and the disconnect switch module.

10. The power test system of the energy storage system according to claim 9, characterized in that: The control system includes a host computer and a BMS main control module connected thereto, wherein the BMS main control module is used to obtain voltage and current information of the load circuit and send it to the host computer, and is also used to control the circuit breaker module and the short-circuit switch module according to the instructions of the host computer; The host computer is used to calculate the load circuit power according to the voltage and current information of the load circuit, and is also used to send control instructions of the short-circuit switch module and the circuit-breaking switch module to the BMS main control module.

11. The power test system of the energy storage system according to claim 10, characterized in that: The control system further comprises a load resistor temperature acquisition module, which is connected to the host computer and sends temperature information of each load resistor to the host computer.

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