Simulation battery circuit and circuit board thereof, and simulation battery pack

Abstract

The utility model belongs to the technical field of battery management system testing, and provides a simulation battery circuit, a circuit board thereof and a simulation battery pack, the output end of each voltage regulation circuit is provided with a first output port and a second output port to output the voltage value of the simulation battery pack; the first output port of each voltage regulation circuit is connected to the second output port of the adjacent voltage regulation circuit; the input end of each voltage acquisition circuit is respectively connected with the first output port and the second output port of the voltage regulation circuit; and the MCU master control module is configured to adjust the voltage value output by the voltage adjusting circuit according to the output voltage value acquired by the voltage acquisition circuit. The utility model has the advantages that a plurality of simulation battery circuit boards are integrated to form the simulation battery pack and are connected to the upper computer, the upper computer controls the string number of the output single voltage so as to realize the flexibility and variability of the string number of the output single voltage, and meanwhile, the arbitrary control of the voltage output of the single cell can be realized through software.

Description

Technical Field

[0001] This utility model relates to the field of battery management system testing technology, and in particular to a simulated battery circuit and its circuit board, and a simulated battery pack. Background Technology

[0002] With the popularization of new energy vehicles, the battery management system (BMS) plays a role in monitoring battery health. Before the BMS is installed in the battery pack, various functional tests need to be carried out in the laboratory. However, the battery pack is large and has certain dangers, so it is not suitable to place it in the laboratory for testing. Therefore, a battery simulation device needs to be introduced into the laboratory, whose function is to simulate the battery output voltage and send it to the BMS acquisition terminal.

[0003] In existing technologies, a voltage reference circuit is used to arbitrarily set the output voltage value by changing the resistance value. However, this method can only change the output voltage value by changing the resistance value, that is, a fixed resistance value corresponds to a fixed voltage value. At this time, the voltage value can only be changed by removing and soldering the resistor on the PCB board. Therefore, when the resistance value is determined, it is not possible to arbitrarily control the output voltage of a single cell. Utility Model Content

[0004] The purpose of this invention is to provide a simulated battery circuit and its circuit board, as well as a simulated battery pack, to solve the above-mentioned problems.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] An analog battery circuit includes:

[0007] An output voltage regulation module includes at least two identical voltage regulation circuits, the input terminals of which are connected to a power supply; each voltage regulation circuit has a first output port and a second output port to output the voltage value of an analog battery pack; the first output port of each voltage regulation circuit is connected to the second output port of the adjacent voltage regulation circuit.

[0008] The voltage acquisition module is equipped with a number of voltage acquisition circuits corresponding to the voltage regulation circuit. The input terminal of each voltage acquisition circuit is connected to the first output port and the second output port of the voltage regulation circuit, respectively.

[0009] The MCU main control module is configured to adjust the voltage value output by the voltage regulation circuit based on the output voltage value obtained by the voltage acquisition circuit.

[0010] Furthermore, a voltage differential amplifier is provided in the voltage acquisition circuit. The input terminals of the voltage differential amplifier are connected to the first output port and the second output port of the voltage regulation circuit, respectively. The output terminal of the voltage differential amplifier is connected to the MCU main control module to output the voltage difference between the first output port and the second output port of the voltage regulation circuit to the MCU main control module.

[0011] Furthermore, it includes a number of modules corresponding to the voltage regulation circuit, wherein a number of current acquisition circuits and sampling resistors corresponding to the voltage regulation circuit are provided; the sampling resistors are respectively set in series on the second output port of each voltage regulation circuit, and each current acquisition circuit is connected in parallel to its corresponding sampling resistor.

[0012] Furthermore, the current acquisition circuit includes at least a voltage differential amplifier and an operational amplifier. The input terminals of the voltage differential amplifier are connected to both ends of the sampling resistor, the output terminal of the voltage differential amplifier is connected to the input terminal of the operational amplifier, and the output terminal of the operational amplifier is connected to the MCU main control module to send the output current value of the voltage regulation circuit to the MCU main control module.

[0013] This utility model also provides a simulated battery circuit board, comprising:

[0014] PCB board and analog battery circuit, with the analog battery circuit integrated on the PCB board;

[0015] The PCB board has an integrated voltage output interface, which is connected to the first output port of the corresponding voltage regulation circuit.

[0016] Furthermore, a communication module is integrated on the PCB board. The communication module is connected to the host computer and is configured to receive the adjustment signals of the host computer to the analog battery pack and send them to the MCU main control module, and read the output voltage value obtained by the MCU main control module and send it to the host computer.

[0017] Furthermore, the PCB board also integrates DIP switches, and the DIP switch states serve as the sequential numbers of the analog battery circuit boards; the host computer reads the DIP switch states via the communication module to determine the sequential numbers of the analog battery circuit boards.

[0018] Furthermore, indicator lights are integrated on the PCB board. These indicator lights are connected to the communication module, and different colors of the indicator lights indicate different communication states of the communication module.

[0019] This utility model also provides a simulated battery pack, including: at least one simulated battery circuit board; when there are multiple simulated battery circuit boards, the simulated battery circuit boards are connected in parallel, the input terminals of all simulated battery circuit boards are connected to the same DC power supply, and the output terminals of all simulated battery circuit boards are used to output simulated voltage values ​​to the battery management system under test.

[0020] Furthermore, the analog battery circuit board integrates an input interface, and the ports of the input interfaces are connected in sequence to form a parallel connection of the analog battery circuit boards, with one of the input interface ports connected to the DC power supply and the communication module.

[0021] Compared with the prior art, this utility model has at least the following beneficial effects:

[0022] (1) A simulated battery circuit board is equipped with multiple voltage regulation circuits to obtain multiple voltage output ports. A voltage acquisition circuit is set on the output port. At the same time, the output terminal of the previous output voltage regulation circuit is used as the reference terminal of the next output voltage regulation circuit for voltage calibration to ensure the accuracy of the single cell voltage output value.

[0023] (2) By setting up a current acquisition circuit to acquire the current of a single string, it has the ability to output balanced current, and because the current of a single string is large enough, the output voltage can be connected in parallel to multiple BMS acquisition terminals.

[0024] (3) Integrate multiple analog battery circuit boards to form an analog battery pack and connect it to the host computer. The host computer directly controls the number of strings of the output single cell voltage. That is, the host computer configures the corresponding number of strings as needed to achieve flexible and variable output single cell voltage string number.

[0025] (4) Connect the simulated battery pack to the host computer, so that the voltage output of the individual cells can be arbitrarily controlled through software. The output voltage of the simulated battery pack can be arbitrarily adjusted by the host computer from 0 to 5V. You only need to set the desired output voltage value of the individual cells on the host computer.

[0026] (5) Connect the simulated battery pack to the same DC power supply so that the number of DC power supplies used in the entire battery pack is reduced.

[0027] (6) When reading the voltage and current values ​​of each cell of the simulated battery pack output by the host computer, the working status of each simulated battery circuit board can be located in time and faults can be detected in time through indicator lights and DIP switches. Attached Figure Description

[0028] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the circuit principle of the simulated battery circuit board in the embodiments provided by this utility model;

[0030] Figure 2 This is a schematic diagram of the simulated battery circuit in the embodiments provided by this utility model;

[0031] Figure 3 This is a flowchart illustrating the specific implementation steps of the simulated battery pack in the embodiments provided by this utility model;

[0032] Figure 4 This is a schematic diagram of a simulated battery pack in the embodiments provided by this utility model. Detailed Implementation

[0033] It should be noted that in this utility model, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0034] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0035] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0036] The following are specific embodiments of the present invention, and the technical solution of the present invention will be further described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0037] like Figure 1 As shown, this embodiment provides a simulated battery circuit board, which includes a PCB board, an input interface, a voltage output interface, an indicator light, a DIP switch, a communication module, a step-down module, a reset module, and a simulated battery circuit integrated on the PCB board.

[0038] The step-down module chip is preferably a DC-DC chip with isolation function. It receives a low-voltage input and outputs a high-voltage output, thus requiring isolation between the low and high voltages. The input of the step-down module is connected to a 24V DC power supply through the input interface of the analog battery circuit board. The module contains multiple DC-DC step-down circuits, including a 24V to 12V step-down circuit and a 12V to 5V step-down circuit. Part of the 12V output from the 24V to 12V step-down circuit serves as the input to the differential amplifiers in the voltage and current sampling circuits, and part serves as the input to the 12V to 5V step-down circuit. The 5V output from the 12V to 5V step-down circuit serves as the power input for various modules in the communication module, reset module, DIP switch, indicator lights, and analog battery circuit.

[0039] In the communication module, the communication chip is preferably a CAN communication chip with isolation function. One end of the communication module is connected to the host computer through the input interface of the simulated battery circuit board. The communication interaction device between the host computer and the simulated battery circuit board is a CAN card. The other end of the communication module is connected to the simulated battery circuit, and the communication method is serial port. The communication module enables information exchange between the simulated battery circuit board and the host computer, including the host computer's command control of the simulated battery circuit and reading information from the simulated battery circuit board.

[0040] The DIP switches can set the sequence of each analog board. The DIP switches are powered by the 5V output from the 12V to 5V circuit in the step-down module. In this embodiment, the DIP switches are preferably slide switches with four positions, connected in series between the 5V power supply and the MCU main control module. When the switch is closed, the 5V power supply is connected to the MCU main control module, corresponding to state 1; when the switch is open, the 5V power supply is not connected to the MCU main control module, corresponding to state 0. Therefore, each DIP switch has 16 states, from 0000 to 1111, corresponding to 16 analog battery circuit boards.

[0041] The indicator lights visually display the abnormal status of the simulated battery circuit board. The indicator light circuit is powered by the 5V output from the 12V to 5V converter in the step-down module. The indicator lights are preferably dual-color LEDs, one red and the other green. When the simulated battery circuit board is communicating normally, the MCU main control module controls the LED to conduct, flashing green; when the simulated battery circuit board is malfunctioning, the MCU main control module controls the LED to conduct, flashing red.

[0042] The reset module can reset the circuit board and program it. The reset module is powered by the 5V voltage output from the 12V to 5V circuit in the step-down module. There is a reset and programming interface on the circuit board. When programming is required, it is connected to the programmer externally. Different programs can be programmed and the baud rate can be changed.

[0043] like Figure 3 As shown, the analog battery circuit includes: an output voltage regulation module, a voltage acquisition module, a current acquisition module, and an MCU main control module.

[0044] The output voltage regulation module contains eight identical voltage regulation circuits. The input of each circuit is connected to a power supply, which is a 5V output from a DC power supply via a step-down module. Each voltage regulation circuit is controlled by the MCU main control module, and the output voltage is adjustable from 0-5V. Each voltage regulation circuit has a first output port and a second output port, serving as the voltage output terminal and reference terminal, respectively. That is, the output terminal of the nth circuit is CELLn, and the reference terminal is CELLn-1.

[0045] Meanwhile, all output ports of the eight voltage regulation circuits are connected in series. The voltage output terminal of the previous voltage regulation circuit serves as the voltage reference terminal of the next voltage regulation circuit. For example, the voltage output terminal CELL1 of the first voltage regulation circuit serves as the voltage reference terminal CELL1 of the second voltage regulation circuit. All voltage regulation circuits output a total of eight voltages, thereby simulating the voltage output of eight individual battery cells. At the same time, voltage calibration can be performed to ensure the accuracy of the voltage output value of a single battery cell.

[0046] The voltage acquisition module is equipped with a number of voltage acquisition circuits corresponding to the voltage regulation circuit, namely 8 voltage sampling circuits. Each voltage sampling circuit is connected to a voltage regulation circuit. The input terminal of the nth voltage sampling circuit is connected to the voltage output terminal CELLn and the voltage reference terminal CELLn-1 of the nth output voltage regulation circuit.

[0047] The voltage sampling circuit preferably uses a high common-mode voltage differential amplifier, which has a very high input common-mode voltage range and can accurately measure differential signals under high common-mode voltages up to ±270V. This voltage differential amplifier is powered by the 12V output from the 24V to 12V circuit of the buck module. CELLn and CELLn-1 are connected to the two input terminals of the voltage differential amplifier, and the output terminal of the voltage differential amplifier is connected to the MCU main control module. The output value is the difference between the two inputs. Thus, the MCU main control module can read the difference between the input voltages, i.e., the voltage value of the nth cell in the series.

[0048] Similarly, each current sampling module has a corresponding number of current acquisition circuits as the voltage regulation circuit, i.e., there are 8 current sampling circuits. Each current sampling circuit is connected to a sampling resistor, which is connected in series with the voltage reference terminal of the voltage regulation circuit, and its two ends are connected to the current sampling circuit.

[0049] The current sampling circuit consists of a high common-mode voltage differential amplifier and an operational amplifier. The voltage differential amplifier is powered by the 12V voltage output from the 24V to 12V circuit of the buck converter, while the operational amplifier is powered by the 5V voltage output from the 12V to 5V circuit of the buck converter.

[0050] The two ends of the sampling resistor are connected to the two ends of a voltage differential amplifier. The voltage differential amplifier outputs the difference between the two voltages, which is the voltage across the sampling resistor. Since the current sampling resistor has a small resistance, the output voltage of the voltage differential amplifier is connected to an operational amplifier for amplification before being output to the MCU main control module. By using the amplification factor and the relationship between voltage and resistance, the current flowing through the current sampling resistor can be obtained. Because the current sampling circuit collects a single series of currents, it has the ability to output balanced currents, and the single series current is large enough that the output voltage can be connected in parallel to the acquisition terminals of multiple battery management systems.

[0051] The MCU main control module is configured to adjust the voltage value output by the voltage regulation circuit based on the output voltage value obtained by the voltage acquisition circuit.

[0052] In addition, such as Figure 1 and Figure 3 As shown, this embodiment also provides a simulated battery pack, which consists of multiple simulated battery circuit boards, preferably... Figure 3 The 16 simulated battery circuit boards shown are illustrated.

[0053] These simulated battery circuit boards are connected in parallel to form a simulated battery pack. The input of the simulated battery pack is connected to the host computer and a DC power supply. The output of all the simulated battery packs outputs simulated voltage values ​​to the acquisition terminal of the battery management system under test, thereby realizing the testing of the battery management system.

[0054] The input interface is optional, with 8 pins defined as CAN_H (CAN communication high), CAN_L (CAN communication low), 24V+ (24V positive), and 24V- (24V negative). The pin definitions of the upper and lower rows of input holes are identical. The upper and lower output holes are connected internally on the PCB board to form a single network, and externally connected to the corresponding input holes on the next circuit board via wiring harnesses. The CAN_H and CAN_L pins are connected to the host computer, and the 24V+ and 24V- pins are connected to a 24V DC power supply. The corresponding number of voltage output interfaces form the voltage output of 128 individual battery cells.

[0055] like Figure 4 As shown, the working process of the simulated battery pack provided in this embodiment is as follows: First, the baud rate of a single circuit board is determined, and the corresponding program is burned through the reset module; the second step is to install the simulated battery pack according to... Figure 3 Connect the circuits as shown. Connect the power cables of each circuit board to a 24V DC power supply. Connect the CAN communication cable to the host computer. Connect the voltage output interfaces to the battery management system's acquisition terminal. Set the DIP switches on each circuit board sequentially from 0000 to 1111. Then, open the host computer interface to set the voltage series number and individual cell voltage values, i.e., set the specific required voltage series number and voltage value. Finally, read the voltage value through the host computer and measure the actual output voltage value with a multimeter. If there is no deviation, it is qualified; if there is a deviation, voltage calibration is required. After voltage calibration, the simulated battery pack can be used for testing the battery management system.

[0056] When an abnormality occurs, the status of the indicator lights can be observed to determine which circuit board is faulty.

[0057] In this embodiment, multiple analog battery circuit boards are integrated to form an analog battery pack and connected to a host computer. The host computer directly controls the number of strings used to output the individual cell voltages; that is, the host computer configures the required number of strings to achieve flexible variability in the number of strings used to output the individual cell voltages. Simultaneously, by connecting the analog battery pack to the host computer, arbitrary control of the individual cell voltage output can be achieved through software. The individual cell output voltages of the analog battery pack can be adjusted arbitrarily within the range of 0-5V by the host computer, simply by setting the desired individual cell voltage value on the host computer.

[0058] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A simulated battery circuit, characterized in that, include: An output voltage regulation module includes at least two identical voltage regulation circuits, the input terminals of which are connected to a power supply; each voltage regulation circuit has a first output port and a second output port to output the voltage value of an analog battery pack; the first output port of each voltage regulation circuit is connected to the second output port of the adjacent voltage regulation circuit. The voltage acquisition module is provided with a number of voltage acquisition circuits corresponding to the voltage regulation circuit, and the input terminal of each voltage acquisition circuit is connected to the first output port and the second output port of the voltage regulation circuit respectively. The MCU main control module is configured to adjust the voltage value output by the voltage regulation circuit based on the output voltage value obtained by the voltage acquisition circuit.

2. The simulated battery circuit according to claim 1, characterized in that, The voltage acquisition circuit is equipped with a voltage differential amplifier. The input terminals of the voltage differential amplifier are respectively connected to the first output port and the second output port of the voltage regulation circuit. The output terminal of the voltage differential amplifier is connected to the MCU main control module to output the voltage difference between the first output port and the second output port of the voltage regulation circuit to the MCU main control module.

3. The simulated battery circuit according to claim 1, characterized in that, The system includes a number of modules corresponding to the voltage regulation circuit, wherein a number of current acquisition circuits and sampling resistors corresponding to the voltage regulation circuits are provided; the sampling resistors are respectively set in series on the second output port of each voltage regulation circuit, and each current acquisition circuit is connected in parallel to its corresponding sampling resistor.

4. The simulated battery circuit according to claim 3, characterized in that, The current acquisition circuit includes at least a voltage differential amplifier and an operational amplifier. The input terminals of the voltage differential amplifier are respectively connected to the two ends of the sampling resistor. The output terminal of the voltage differential amplifier is connected to the input terminal of the operational amplifier. The output terminal of the operational amplifier is connected to the MCU main control module to send the output current value of the voltage regulation circuit to the MCU main control module.

5. A simulated battery circuit board, characterized in that, include: The PCB board and the analog battery circuit as described in any one of claims 1-4, wherein the analog battery circuit is integrated on the PCB board; The PCB board integrates a voltage output interface, which is connected to the first output port of the corresponding voltage regulation circuit.

6. A simulated battery circuit board according to claim 5, characterized in that, The PCB board also integrates a communication module, which is connected to the host computer. The communication module is configured to receive the adjustment signal of the analog battery pack from the host computer and send it to the MCU main control module, and read the output voltage value obtained by the MCU main control module and send it to the host computer.

7. A simulated battery circuit board according to claim 6, characterized in that, The PCB board also integrates a DIP switch, and the DIP switch's corresponding DIP state serves as the sequential number of the analog battery circuit board; the host computer reads the DIP switch's DIP state via the communication module to determine the sequential number of the analog battery circuit board.

8. A simulated battery circuit board according to claim 6, characterized in that, The PCB board also integrates indicator lights, which are connected to the communication module. The indicator lights use different colors to represent different communication states of the communication module.

9. A simulated battery pack, characterized in that, include: At least one analog battery circuit board as described in any one of claims 5-8; when there are multiple analog battery circuit boards, the analog battery circuit boards are connected in parallel, the input terminals of all the analog battery circuit boards are connected to the same DC power supply, and the output terminals of all the analog battery circuit boards are used to output analog voltage values ​​to the battery management system under test.

10. A simulated battery pack according to claim 9, characterized in that, The analog battery circuit board has an integrated input interface, and the ports of the input interface are connected in sequence to form a parallel connection of the analog battery circuit board. One of the input interface ports is connected to a DC power supply and a communication module.

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