Power battery teaching circuit and teaching device

Abstract

The utility model discloses a power battery teaching circuit and teaching equipment relates to power battery teaching technical field. The teaching circuit includes collection and equalization module, electrical detection module, charging detection and control circuit, relay control circuit, high voltage interlock circuit, first communication circuit and main control circuit. Collection and equalization module, electrical detection module are used for collecting battery information and detecting the electrical state information of the circuit to be tested respectively. Charging detection and control circuit are used for detecting and controlling the charging state of the charging gun. The relay control circuit is used for controlling the conduction / turn-off of the relay. The high voltage interlock circuit is used for outputting the interlock signal when detecting the abnormal connection of the high voltage connector. The main control circuit is used for controlling the work of each module and circuit, and sending the collection, detection and execution information to the upper computer through the first communication circuit. The utility model aims at helping students to understand the basic principle of power battery and improving their troubleshooting ability.

Description

Technical Field

[0001] This utility model relates to the field of teaching equipment technology, and in particular to a power battery teaching circuit and teaching equipment. Background Technology

[0002] With the rapid development of new energy technologies, power batteries have become a key component of electric vehicles, energy storage systems, and renewable energy equipment. Battery performance directly affects the range, safety, and efficiency of these devices; therefore, a deep understanding of power battery systems has become an essential skill for technical professionals. Especially against the backdrop of the rapid development of the electric vehicle industry, the demand for professionals in battery design, management, maintenance, and recycling has surged. There is a need to cultivate more practical talents who can deeply understand battery operating principles, parameter monitoring, fault diagnosis, and equalization control.

[0003] However, due to the complexity of the technical principles of power battery systems, related teaching faces significant challenges. Current power battery training largely relies on videos, PowerPoint presentations, or textbooks, lacking intuitiveness and interactivity, and failing to demonstrate real-time changes in battery parameters. Consequently, students often struggle to deeply understand the technical principles of power battery packs, hindering their ability to effectively troubleshoot power battery malfunctions. Utility Model Content

[0004] The main purpose of this utility model is to provide a teaching circuit for power batteries, which aims to solve the problems of existing power battery teaching lacking intuitiveness, interactivity and practical support, making it difficult for students to understand the technical principles of power battery packs and effectively improve their ability to troubleshoot power battery faults.

[0005] To achieve the above objectives, the present invention proposes a power battery teaching circuit, comprising:

[0006] The acquisition and equalization module is electrically connected to the battery pack and is used to acquire the status information of multiple individual cells in the battery pack. When the voltage difference between multiple individual cells exceeds a preset threshold based on the acquired information, the module performs voltage equalization processing on the multiple individual cells.

[0007] An electrical testing module, connected to the circuit under test, is used to detect the electrical status information of the circuit under test.

[0008] The charging detection and control circuit is provided with a charging terminal for connecting the charging gun, and is used to detect and control the charging status of the charging gun.

[0009] The relay control circuit is provided with control terminals for connecting the relay and for controlling the on and off states of the relay.

[0010] The high-voltage interlock circuit is equipped with a high-voltage detection terminal for connecting a high-voltage connector, which outputs an interlock signal when an abnormality is detected in the high-voltage connection line of the high-voltage connector; wherein, the interlock signal is used to indicate the disconnection of the high-voltage connection line of the high-voltage connector.

[0011] The first communication circuit is communicatively connected to the acquisition and equalization module and the electrical detection module, and is also used for communication connection with the host computer.

[0012] The main control circuit is connected to the charging detection and control circuit, the relay control circuit, the high-voltage interlock circuit, and the first communication circuit, respectively. It is used to control the operation / stop operation of the acquisition and equalization module, the electrical detection module, the charging detection and control circuit, the relay control circuit, and the high-voltage interlock circuit, and to send the status information of multiple individual batteries acquired by the acquisition and equalization module and the electrical status information of the circuit under test detected by the electrical detection module to the host computer through the first communication circuit.

[0013] In one embodiment, the acquisition and equalization module includes:

[0014] A second communication circuit is communicatively connected to the first communication circuit.

[0015] Temperature acquisition circuit is used to acquire ambient temperature information of the area where the battery pack is located;

[0016] A voltage acquisition and equalization circuit is connected to the temperature acquisition circuit and the second communication circuit, respectively, and is provided with voltage acquisition terminals for connecting to each individual cell in the battery pack. The voltage acquisition and equalization circuit is used to acquire the voltage of multiple individual cells, and when the voltage difference between multiple individual cells exceeds a preset threshold, it performs voltage equalization processing on the multiple individual cells. The voltage acquisition and equalization circuit is also used to send equalization information, the voltage of multiple individual cells, and the ambient temperature information acquired by the temperature acquisition circuit to the main control circuit through the second communication circuit, and to operate / stop operating according to the first control signal of the main control circuit.

[0017] In one embodiment, the electrical detection module includes:

[0018] A third communication circuit is communicatively connected to the first communication circuit.

[0019] An adhesion detection circuit is provided with an adhesion detection terminal for connecting the circuit to be tested. The adhesion detection circuit is used to detect the adhesion status of the circuit to be tested.

[0020] A pre-charge detection circuit is provided with a pre-charge detection terminal for connecting to the circuit under test. The pre-charge detection circuit is used to detect the pre-charge voltage of the circuit under test.

[0021] A leakage current detection circuit is provided with a leakage current detection terminal for connecting to the circuit under test. The leakage current detection circuit is used to detect the resistance value of the circuit under test.

[0022] A current detection circuit is provided with a current detection terminal for connecting to the circuit under test. The current detection circuit is used to detect the magnitude of the current flowing through the circuit under test.

[0023] The detection control circuit is connected to the adhesion detection circuit, the pre-charge detection circuit, the leakage detection circuit, and the current detection circuit, respectively. It is used to control the operation of the adhesion detection circuit, the pre-charge detection circuit, the leakage detection circuit, and the current detection circuit, respectively. It also sends the adhesion status, pre-charge voltage, resistance value, and current magnitude of the circuit under test to the main control circuit through the third communication circuit, and is used to start / stop operation according to the second control signal of the main control circuit.

[0024] In one embodiment, the adhesion detection circuit includes a first Zener diode, a second Zener diode, a third Zener diode, a first transformer, a first diode, a first transistor, a second transistor, and a first optocoupler circuit;

[0025] In this circuit, the negative terminal of the first Zener diode, the first adhesion detection terminal of the adhesion detection circuit, and the negative terminal of the third Zener diode are connected; the positive terminal of the first Zener diode, the second adhesion detection terminal of the adhesion detection circuit, and the positive terminal of the second Zener diode are connected; the first input terminal of the first transformer is connected to the first power supply terminal of the adhesion detection circuit; the second input terminal of the first transformer is grounded; the first output terminal of the first transformer and the positive terminal of the third Zener diode are connected to the first input terminal of the first optocoupler circuit; the second output terminal of the first transformer and the positive terminal of the first diode are connected to the emitter of the first transistor; the negative terminals of the second Zener diode and the first diode are connected to the base of the first transistor; the collector of the first transistor is connected to the second input terminal of the first optocoupler circuit; the first output terminal of the first optocoupler circuit is connected to the second power supply terminal of the adhesion detection circuit; the second output terminal of the first optocoupler circuit is connected to the base of the second transistor; the emitter of the second transistor is grounded; and the collector of the second transistor is connected to the first signal input terminal of the detection control circuit.

[0026] In one embodiment, the pre-charge detection circuit includes a second optocoupler circuit, a third optocoupler circuit, a third transistor, and a first operational amplifier chip;

[0027] In this circuit, the first output terminal of the second optocoupler circuit is connected to the first pre-charge detection terminal of the pre-charge detection circuit; the first output terminal of the third optocoupler circuit is connected to the second pre-charge detection terminal of the pre-charge detection circuit; the second output terminal of the second optocoupler circuit is connected to the input terminal of the first operational amplifier chip; the second output terminal of the third optocoupler circuit is grounded; the first input terminals of the second and third optocouplers circuits are connected to the power supply terminal of the pre-charge detection circuit; the second input terminals of the second and third optocouplers circuits are respectively connected to the first and second enable terminals of the detection control circuit; the first output terminal of the first operational amplifier chip is connected to the second signal input terminal of the detection control circuit; the second output terminal of the first operational amplifier chip is connected to the base of the third transistor; the emitter of the third transistor is grounded; and the drain of the third transistor is connected to the third signal input terminal of the detection control circuit.

[0028] In one embodiment, the leakage current detection circuit includes a fourth optocoupler circuit, a fifth optocoupler circuit, and a second operational amplifier chip;

[0029] Specifically, the first output terminal of the fourth optocoupler circuit is connected to the first leakage detection terminal of the leakage detection circuit; the first output terminal of the fifth optocoupler circuit is connected to the second leakage detection terminal of the leakage detection circuit; the second output terminal of the fourth optocoupler circuit is connected to the input terminal of the second operational amplifier chip; the second output terminal of the fifth optocoupler circuit is grounded; the first input terminals of the fourth and fifth optocouplers circuits are connected to the power supply terminal of the leakage detection circuit; the second input terminals of the fourth and fifth optocouplers circuits are respectively connected to the third and fourth enable terminals of the detection control circuit; the first output terminal of the second operational amplifier chip is connected to the fourth signal input terminal of the detection control circuit; and the second output terminal of the second operational amplifier chip is connected to the fifth signal input terminal of the detection control circuit.

[0030] In one embodiment, the charging detection and control circuit includes:

[0031] The CC detection circuit is provided with a CC detection terminal for connecting the charging gun. The CC detection circuit is connected to the main control circuit. The CC detection circuit is used to detect the charging access status of the charging gun and output a corresponding access status detection signal to the main control circuit.

[0032] The CP control circuit is provided with a CP control terminal for connecting the charging gun. The CP control circuit is connected to the main control circuit and is used to control the charging state of the charging gun according to the third control signal of the main control circuit.

[0033] In one embodiment, the high-voltage interlock circuit includes:

[0034] The high-voltage interlock output circuit is provided with a high-voltage output terminal at one end of the high-voltage connection line connected to the high-voltage connector. The high-voltage interlock output circuit is connected to the main control circuit and is used to output the PWM signal provided by the main control circuit to one end of the high-voltage connection line.

[0035] The high-voltage interlock input circuit is provided with a high-voltage input terminal at the other end of the high-voltage connection line connected to the high-voltage connector. The high-voltage interlock input circuit is connected to the main control circuit. The high-voltage interlock input circuit is used to receive the PWM signal input from the other end of the high-voltage connection line, and when it detects that the change in the duty cycle of the PWM signal exceeds a preset range, it outputs an interlock signal to the main control circuit.

[0036] In one embodiment, the relay control circuit includes a first switching transistor, a second diode, a third diode, a fourth diode, a first fuse, a fourth transistor, a first resistor, and a second resistor;

[0037] In this circuit, the controlled terminal of the first switching transistor is connected to the first control terminal of the main control circuit; the first terminal of the first switching transistor, the anode of the second diode, the cathode of the third diode, and the cathode of the fourth diode are connected to one end of the first fuse; the second terminal of the first switching transistor, the anode of the third diode, and one end of the second resistor are grounded to the emitter of the fourth transistor; the cathode of the second diode is connected to the first power supply terminal of the relay control circuit; the anode of the fourth diode and the other end of the second resistor are connected to one end of the first resistor; the other end of the first resistor is connected to the base of the fourth transistor; the collector of the fourth transistor is connected to the second control terminal of the main control circuit; and the other end of the first fuse is connected to the relay.

[0038] This utility model also proposes a teaching device, including a battery pack, a circuit under test, a charging gun, a relay, a high-voltage connector, and the power battery teaching circuit described above. The battery pack is connected to the acquisition and equalization module, the circuit under test is connected to the electrical detection module, the relay is connected to the charging terminal of the charging detection and control circuit, the relay is connected to the switching terminal of the relay control circuit, and the high-voltage connector is connected to the high-voltage detection terminal of the high-voltage interlock circuit.

[0039] This utility model employs a power battery teaching circuit, including a data acquisition and balancing module, an electrical detection module, a charging detection and control circuit, a relay control circuit, a high-voltage interlock circuit, a first communication circuit, and a main control circuit. The data acquisition and balancing module collects status information from multiple individual cells in the battery pack, such as voltage, temperature, and SOC. When the voltage difference between multiple individual cells exceeds a preset threshold based on the collected information, it performs voltage balancing processing on the individual cells. The electrical detection module detects the electrical status information of the circuit under test, such as the adhesion status, pre-charge voltage, leakage status, and current magnitude of the main positive / negative relays, pre-charge circuit, and high-voltage distribution unit. This information is uploaded to a host computer via the first communication circuit for display, helping students learn about the actual operating status of power batteries during operation. The charging detection and control circuit can detect and control the charging status of the charging gun. It has charging terminals for connecting the charging gun, detects the connection status by acquiring the CC signal, and communicates with the charging gun via the CP signal to obtain information such as charging voltage and current. This enables teaching the entire charging process—"gun insertion, self-test, pre-charging, power-on, and charging"—helping students understand the charging principle of power batteries. The relay control circuit controls the on / off state of the relays, facilitating the control of power supply to different power battery circuits during teaching. The high-voltage interlock circuit outputs an interlock signal when an abnormality is detected in the high-voltage connection line of the high-voltage connector, simulating the safety disconnection mechanism of a real vehicle. The main control circuit controls the operation / stop of the acquisition and equalization module, electrical detection module, charging detection and control circuit, relay control circuit, and high-voltage interlock circuit, achieving modular control of the teaching circuit. The main control circuit also sends the status information of multiple individual batteries acquired by the acquisition and equalization module and the electrical status information of the circuit under test detected by the electrical detection module to the host computer, helping students learn the charging actions of the power battery charging gun, relay on / off, and high-voltage interlock. In this way, the operation and testing process of a power battery can be realistically simulated through this power battery teaching circuit, which helps students understand the basic principles of power batteries and improves their ability to troubleshoot power battery faults. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0041] Figure 1A schematic diagram of an embodiment of the power battery teaching circuit provided by this utility model;

[0042] Figure 2 A schematic diagram of another embodiment of the power battery teaching circuit provided by this utility model;

[0043] Figure 3 An electronic circuit diagram of an adhesion detection circuit according to an embodiment of the power battery teaching circuit provided by this utility model;

[0044] Figure 4 An electronic circuit diagram of a pre-charge detection circuit according to an embodiment of the power battery teaching circuit provided by this utility model;

[0045] Figure 5 An electronic circuit diagram of a leakage current detection circuit according to an embodiment of the power battery teaching circuit provided by this utility model;

[0046] Figure 6 An electronic circuit diagram of a charging detection and control circuit according to an embodiment of the power battery teaching circuit provided by this utility model;

[0047] Figure 7 Electronic circuit diagram of a high-voltage interlock circuit in an embodiment of the power battery teaching circuit provided by this utility model;

[0048] Figure 8 The electronic circuit diagram of the relay control circuit of one embodiment of the power battery teaching circuit provided by this utility model.

[0049] Explanation of icon numbers:

[0050]

[0051] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0052] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0053] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0054] Furthermore, the use of terms such as "first" and "second" in this utility model 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. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0055] Due to the complexity of the technical principles of power battery systems, related teaching faces significant challenges. Current power battery training largely relies on videos, PowerPoint presentations, or textbooks, lacking intuitiveness and interactivity, and failing to demonstrate real-time changes in battery parameters. Consequently, students often struggle to gain a deep understanding of the technical principles of power battery packs, which hinders their ability to effectively troubleshoot power battery malfunctions.

[0056] This utility model proposes a teaching circuit for power batteries.

[0057] Please see Figure 1 In one embodiment of this utility model, the power battery teaching circuit includes:

[0058] The acquisition and equalization module 10 is electrically connected to the battery pack and is used to acquire the status information of multiple individual cells in the battery pack. When the voltage difference between multiple individual cells exceeds a preset threshold based on the acquired information, the module performs voltage equalization processing on the multiple individual cells.

[0059] The electrical testing module 20 is connected to the circuit under test and is used to detect the electrical status information of the circuit under test.

[0060] The charging detection and control circuit 30 is provided with a charging terminal for connecting the charging gun, and is used to detect and control the charging status of the charging gun.

[0061] The relay control circuit 40 is provided with control terminals for connecting the relay and for controlling the on and off states of the relay.

[0062] The high-voltage interlock circuit 50 is provided with a high-voltage detection terminal for connecting to the high-voltage connector, and is used to output an interlock signal when an abnormality is detected in the high-voltage connection line of the high-voltage connector; wherein, the interlock signal is used to indicate the disconnection of the high-voltage connection line of the high-voltage connector;

[0063] The first communication circuit 60 is connected to the acquisition and equalization module 10 and the electrical detection module 20, respectively, and is also used for communication connection with the host computer.

[0064] The main control circuit 70 is connected to the charging detection and control circuit 30, the relay control circuit 40, the high-voltage interlock circuit 50, and the first communication circuit 60, respectively. It is used to control the operation / stop operation of the acquisition and equalization module 10, the electrical detection module 20, the charging detection and control circuit 30, the relay control circuit 40, and the high-voltage interlock circuit 50, and to send the status information of multiple individual batteries acquired by the acquisition and equalization module 10 and the electrical status information of the circuit under test detected by the electrical detection module 20 to the host computer through the first communication circuit 60.

[0065] It should be noted that this embodiment aims to solve the problems of lack of intuitiveness, insufficient interactivity, invisible parameters, and difficulty in cultivating fault diagnosis ability in traditional power battery teaching by proposing an integrated, modular, and interactive teaching circuit.

[0066] In one implementation, please refer to Figure 2 The acquisition and equalization module 10 includes:

[0067] The second communication circuit 11 is communicatively connected to the first communication circuit 60.

[0068] Temperature acquisition circuit 12 is used to acquire ambient temperature information of the area where the battery pack is located;

[0069] The voltage acquisition and equalization circuit 13 is connected to the temperature acquisition circuit 12 and the second communication circuit 11, respectively, and is provided with voltage acquisition terminals for connecting to each individual cell in the battery pack. The voltage acquisition and equalization circuit 13 is used to acquire the voltage of multiple individual cells, and when the voltage difference between multiple individual cells exceeds a preset threshold, it performs voltage equalization processing on multiple individual cells. The voltage acquisition and equalization circuit 13 is also used to send equalization information, the voltage of multiple individual cells and the ambient temperature information acquired by the temperature acquisition circuit 12 to the main control circuit 70 through the second communication circuit 11, and to operate / stop operating according to the first control signal of the main control circuit 70.

[0070] It should be noted that the second communication circuit 11 can use a communication chip of model SN65HVD232DR, the temperature acquisition circuit 12 can use an NTC (Negative Temperature Coefficient) thermistor to acquire ambient temperature information of the area where the battery pack is located, and the voltage acquisition and equalization circuit 13 can use an SH367309 chip to manage the battery. It supports voltage monitoring, charge / discharge control, temperature detection input, and equalization functions, and is equipped with a communication structure to communicate with the second communication circuit 11. In this embodiment, the acquisition and equalization module 10 may also include a charge / discharge control circuit, which is connected to the voltage acquisition and equalization circuit 13 and is used to control the charging and discharging process of the battery pack. The acquisition and equalization module 10 may also include a display circuit, which is connected to the voltage acquisition and equalization circuit 13 and can directly display the operating status information of multiple individual cells in the battery pack. The voltage acquisition and equalization circuit 13 may include a power switch circuit. Upon receiving a power-on signal from the main control circuit 70, it connects to battery power to start operation; otherwise, it disconnects battery power and stops operating. This reduces the power consumption of the acquisition and equalization circuit and allows the main control circuit 70 to control its operation. It is understood that the voltage acquisition and equalization circuit 13 can also acquire information such as the state of charge (SOC) of each individual battery cell and send it to the main control circuit 70.

[0071] It should be noted that the data acquisition and equalization module 10 is one of the core components of the power battery teaching system. Its design aims to enable real-time acquisition of the voltage and ambient temperature of each individual cell in the battery pack, data communication, and voltage equalization control for teaching purposes. During the teaching process, students can record the initial voltage and current of each cell, perform a charge-discharge cycle, observe the voltage and current conditions during the charge-discharge process, and analyze the reasons. They can also set an equalization threshold; when the voltage difference between multiple individual cells exceeds this threshold, equalization is initiated, and the voltage change curve of each cell over time is recorded. Students can also record the equalization time required to understand the equalization process in power batteries. Simultaneously, during the aforementioned charge-discharge and equalization processes, the temperature change of the environment surrounding the battery pack can be observed, helping to understand how the ambient temperature parameters of the battery are acquired in practical applications.

[0072] In yet another implementation, please refer to Figure 2 The electrical testing module 20 includes:

[0073] The third communication circuit 21 is communicatively connected to the first communication circuit 60.

[0074] The adhesion detection circuit 22 is provided with adhesion detection terminals for connecting the circuit to be tested. The adhesion detection circuit 22 is used to detect the adhesion status of the circuit to be tested.

[0075] The pre-charge detection circuit 23 is provided with a pre-charge detection terminal for connecting the circuit under test. The pre-charge detection circuit 23 is used to detect the pre-charge voltage of the circuit under test.

[0076] The leakage current detection circuit 24 is provided with a leakage current detection terminal for connecting the circuit to be tested. The leakage current detection circuit 24 is used to detect the resistance value of the circuit to be tested.

[0077] The current detection circuit 25 is provided with a current detection terminal for connecting to the circuit under test. The current detection circuit 25 is used to detect the magnitude of the current flowing through the circuit under test.

[0078] The detection control circuit 26 is connected to the adhesion detection circuit 22, the pre-charge detection circuit 23, the leakage detection circuit 24, and the current detection circuit 25, respectively. It is used to control the operation of the adhesion detection circuit 22, the pre-charge detection circuit 23, the leakage detection circuit 24, and the current detection circuit 25, respectively. It also sends the adhesion status, pre-charge voltage, resistance value, and current magnitude of the circuit under test to the main control circuit 70 through the third communication circuit 21, and is used to start / stop operation according to the second control signal of the main control circuit 70.

[0079] In this embodiment, the circuit under test may include a relay. Students can connect the two power contacts of the relay to the adhesion detection terminal and apply a low voltage signal to the circuit through the detection control circuit 26 to detect whether current still flows through the relay in the "open" state, thereby determining whether there is an adhesion fault in the relay contacts (i.e., the contacts are fused together and cannot be disconnected). If abnormal conduction is detected, it is determined to be adhesion, which poses a safety hazard. The circuit under test may include a pre-charge circuit for pre-charging the power battery. Students can collect the output of the pre-charge circuit through the pre-charge detection terminal and collect the pre-charge voltage in real time during the pre-charge process through the detection control circuit 26 to determine whether the pre-charge is complete (e.g., whether the voltage is close to or above 90% of the total voltage of the power battery). If the pre-charge voltage rises slowly or does not reach the threshold, it indicates that the pre-charge resistor is damaged or has poor contact. The circuit under test may include components that are prone to leakage, such as connectors. Students can connect the connector through the leakage detection terminal and collect the voltage at both ends of the connector through the detection control circuit 26. Based on the correspondence between its voltage and resistance value, its insulation resistance value is obtained. If its insulation resistance value is detected to be lower than the safety threshold, it is determined that there is a risk of leakage, which may cause electric shock or short circuit accidents. The circuit under test can also include different circuits within the power battery. Students can connect these circuits through current detection terminals and use the detection control circuit 26 to collect the current on the circuits to determine whether the operating current of the power battery on that circuit is normal. The leakage detection circuit 24 can use a Hall sensor to collect the current flowing through it and output a corresponding voltage signal to the detection control circuit 26. The detection control circuit 26 then calculates the corresponding current magnitude based on the voltage-current relationship.

[0080] In this embodiment, the acquisition and equalization module 10 can collect information such as voltage, temperature, and SOC of each individual battery in the battery pack in real time. The electrical detection module 20 can be used to detect the adhesion status, pre-charge voltage, leakage status, and current magnitude of the main positive / negative relays, pre-charge circuit, high-voltage power distribution unit, and other circuits under test. The above information can be uploaded to the main control circuit 70 through the first communication circuit 60 and then transmitted to the host computer for display. Among them, the acquisition and equalization module 10 can perform voltage equalization processing on multiple individual batteries when it detects that the voltage difference between multiple individual batteries exceeds a preset threshold based on the acquired information. In addition, this embodiment includes a charging detection and control circuit 30, which can simulate a real charging scenario. It is equipped with a charging terminal that can be connected to a charging gun. It detects the connection status of the charging gun by acquiring the CC signal and communicates with the charging gun through the CP signal to obtain information such as charging voltage and current. This realizes the teaching of the entire process of "plugging in the charging gun, self-testing, pre-charging, powering on, and charging" during the charging process, helping students understand the charging principle of power batteries. In this embodiment, the relay control circuit 40 can control the on / off process of the relays, which is beneficial for controlling the power supply on / off of different power battery circuits during teaching. Multiple relay control circuits 40 can be used to control the on / off sequence of relays such as main positive, main negative, and pre-charge relays. This on / off sequence can be automatically controlled by the main control circuit 70 according to a program, or it can be manually triggered by students. Students can observe the effects of different operating sequences to further deepen their understanding of the power battery principle. The high-voltage interlock circuit 50 is connected to each high-voltage connector through the high-voltage detection terminal. When a high-voltage connector becomes loose or disconnected, an interlock signal is output, and the main control circuit 70 immediately sends a high-voltage cut-off signal to prevent the high-voltage connector from being plugged in or unplugged while energized, simulating the "high-voltage cut-off" safety mechanism of a real vehicle. The main control circuit 70 can control the operation / stopping of the acquisition and equalization module 10 and the electrical detection module 20 respectively. When the acquisition and equalization module 10 and the electrical detection module 20 are working, the main control circuit 70 receives data from them. The main control circuit 70 can also control the charging gun, relay switching, high-voltage interlocking, and other actions, and send the execution data, collected data, and test data to the host computer (such as a teaching computer or touch screen) for display via the first communication circuit 60. In this way, this power battery teaching circuit can realistically simulate the operation and testing process of a power battery, helping students understand the basic principles of power batteries and improving their ability to troubleshoot power battery faults.

[0081] Please see Figure 3 In one embodiment of this utility model, the adhesion detection circuit 22 includes a first Zener diode DW1, a second Zener diode DW2, a third Zener diode DW3, a first transformer T1, a first diode D1, a first transistor Q1, a second transistor Q2, and a first optocoupler circuit OC1.

[0082] In this circuit, the negative terminal of the first Zener diode DW1, the first adhesion detection terminal (HV+) of the adhesion detection circuit 22, and the negative terminal of the third Zener diode DW3 are connected; the positive terminal of the first Zener diode DW1, the second adhesion detection terminal (HP+) of the adhesion detection circuit 22, and the positive terminal of the second Zener diode DW2 are connected; the first input terminal of the first transformer T1 is connected to the first power supply terminal of the adhesion detection circuit 22; the second input terminal of the first transformer T1 is grounded; the first output terminal of the first transformer T1 and the positive terminal of the third Zener diode DW3 are connected to the first input terminal of the first optocoupler circuit OC1; and the second output terminal of the first transformer T1... The anode of the first diode D1 is connected to the emitter of the first transistor Q1. The cathode of the second Zener diode DW2 and the cathode of the first diode D1 are connected to the base of the first transistor Q1. The collector of the first transistor Q1 is connected to the second input terminal of the first optocoupler circuit OC1. The first output terminal of the first optocoupler circuit OC1 is connected to the second power supply terminal of the adhesion detection circuit 22. The second output terminal of the first optocoupler circuit OC1 is connected to the base of the second transistor Q2. The emitter of the second transistor Q2 is grounded. The collector of the second transistor Q2 is connected to the first signal input terminal (REL_DET terminal) of the detection control circuit 26.

[0083] Understandably, the adhesion detection circuit 22 can also be adapted to include other resistors and capacitors to improve circuit stability.

[0084] In this embodiment, the HP+ terminal is connected to the high-voltage positive terminal of the relay contact output, the HV+ terminal is connected to the high-voltage positive terminal of the relay contact input, and the REL_DET terminal is used to output the relay contact sticking state. When the relay is normally open, there is a significant voltage difference between the HV+ and HP+ terminals, causing the second Zener diode DW2 and the first Zener diode DW1 to reverse break down and conduct, the first transistor Q1 to conduct, current flows through the input side of the first optocoupler circuit OC1, and thus current also flows through the output side, the second transistor Q2 to conduct, and the level of the REL_DET terminal is pulled low. When the relay sticks, the voltage difference between the HV+ and HP+ terminals is essentially zero, the first transistor Q1 is turned off, no current flows through the input side of the first optocoupler circuit OC1, and there is no current on its output side, the second transistor Q2 is turned off, and the level of the REL_DET terminal is no longer pulled low. Thus, the main control circuit 70 can detect the relay sticking state by detecting whether the level of the REL_DET terminal is pulled low. Moreover, this embodiment uses optocouplers for isolation detection, resulting in high circuit safety.

[0085] Please see Figure 4 In one embodiment of the present invention, the pre-charge detection circuit 23 includes a second optocoupler circuit OC2, a third optocoupler circuit OC3, a third transistor Q3, and a first operational amplifier chip U1.

[0086] In this circuit, the first output terminal of the second optocoupler circuit OC2 is connected to the first pre-charge detection terminal (HP+) of the pre-charge detection circuit 23; the first output terminal of the third optocoupler circuit OC3 is connected to the second pre-charge detection terminal (HP-) of the pre-charge detection circuit 23; the second output terminal of the second optocoupler circuit OC2 is connected to the input terminal of the first operational amplifier chip U1; the second output terminal of the third optocoupler circuit OC3 is grounded; and the first input terminals of the second optocoupler circuit OC2 and the third optocoupler circuit OC3 are connected to the power supply terminal of the pre-charge detection circuit 23. The second input terminal of the first operational amplifier chip U1 and the second input terminal of the third optocoupler circuit OC3 are respectively connected to the first enable terminal (HPDET+_EN terminal) and the second enable terminal (HPDET-_EN terminal) of the detection control circuit 26. The first output terminal of the first operational amplifier chip U1 is connected to the second signal input terminal (CH_ADC terminal) of the detection control circuit 26. The second output terminal (CH_OK terminal) of the first operational amplifier chip U1 is connected to the base of the third transistor Q3. The emitter of the third transistor Q3 is grounded. The drain of the third transistor Q3 is connected to the third signal input terminal of the detection control circuit 26.

[0087] Understandably, the pre-charge detection circuit 23 can also be adapted to include other resistors and capacitors to improve circuit stability.

[0088] In this embodiment, the HPDET+_EN and HPDET-_EN terminals are the enable terminals of the second optocoupler circuit OC2 and the third optocoupler circuit OC3, respectively. Sending control signals to the corresponding optocouplers through these two ports enables or disables the operation of the optocoupler circuits, thereby controlling whether pre-charge detection is performed. When pre-charging begins, a voltage difference is formed between the HP+ and HP- terminals. The voltage at the HP+ terminal continuously increases and is sent to the input terminal of the first operational amplifier chip U1 for amplification and filtering. The result is then output to the detection control circuit 26 via the CH_ADC terminal for analysis, yielding the corresponding pre-charge detection result. Simultaneously, if the pre-charge voltage reaches a preset voltage, such as approaching or exceeding 90% of the total voltage of the power battery, the CH_OK terminal sends a signal to turn on the third transistor Q3, triggering subsequent actions of the detection control circuit 26, such as illuminating an indicator light, to indicate that pre-charging is complete. Furthermore, this embodiment utilizes optocouplers for isolation control, resulting in strong anti-interference capabilities.

[0089] Please see Figure 5 In one embodiment of the present invention, the leakage current detection circuit 24 includes a fourth optocoupler circuit OC4, a fifth optocoupler circuit OC5, and a second operational amplifier chip U2.

[0090] Specifically, the first output terminal of the fourth optocoupler circuit OC4 is connected to the first leakage detection terminal of the leakage detection circuit 24; the first output terminal of the fifth optocoupler circuit OC5 is connected to the second leakage detection terminal of the leakage detection circuit 24; the second output terminal of the fourth optocoupler circuit OC4 is connected to the input terminal of the second operational amplifier chip U2; the second output terminal of the fifth optocoupler circuit OC5 is grounded; the first input terminals of the fourth optocoupler circuit OC4 and the fifth optocoupler circuit OC5 are connected to the power supply terminal of the leakage detection circuit 24; the second input terminals of the fourth optocoupler circuit OC4 and the fifth optocoupler circuit OC5 are respectively connected to the third and fourth enable terminals of the detection control circuit 26; the first output terminal of the second operational amplifier chip U2 is connected to the fourth signal input terminal of the detection control circuit 26; and the second output terminal of the second operational amplifier chip U2 is connected to the fifth signal input terminal of the detection control circuit 26.

[0091] Understandably, the leakage current detection circuit 24 can also be adapted to include other resistors and capacitors to improve circuit stability.

[0092] In this embodiment, the HPDET+_EN and HPDET-_EN terminals are the enable terminals of the fourth optocoupler circuit OC4 and the fifth optocoupler circuit OC5, respectively. Sending control signals to the corresponding optocouplers through these two ports enables or disables the operation of the optocoupler circuits, thereby controlling whether leakage current detection is performed. When leakage current detection begins, the voltage at the HP+ terminal is sent to the input terminal of the second operational amplifier chip U2 for amplification and filtering, and then output to the detection control circuit 26 via the LPD+_ADC and LPD-_ADC terminals for analysis to obtain the corresponding leakage current detection result. Furthermore, this embodiment uses optocouplers for isolated detection, resulting in strong anti-interference capabilities. In this embodiment, a linear relationship is established between the voltage detected at the HP+ terminal and the measured insulation resistance value. If the insulation resistance value of the circuit under test is less than 20 kΩ based on the voltage detected at the HP+ terminal, a serious leakage current is confirmed in the circuit under test; if the insulation resistance value is greater than or equal to 20 kΩ and less than 120 kΩ based on the voltage detected at the HP+ terminal, a general leakage current is confirmed in the circuit under test.

[0093] Please see Figure 6 In one embodiment of this utility model, the charging detection and control circuit 30 includes:

[0094] CC detection circuit 31 is provided with a CC detection terminal for connecting the charging gun. CC detection circuit 31 is connected to main control circuit 70. CC detection circuit 31 is used to detect the charging access status of the charging gun and output the corresponding access status detection signal to main control circuit 70.

[0095] The CP control circuit 32 is provided with a CP control terminal for connecting the charging gun. The CP control circuit 32 is connected to the main control circuit 70. The CP control circuit 32 is used to control the charging state of the charging gun according to the third control signal of the main control circuit 70.

[0096] In this embodiment, the CC detection circuit 31 includes a second operational amplifier OP2, an interface J1, and other adaptively configured resistors and capacitors; the CP control circuit 32 may include a first operational amplifier OP1, a sixth transistor Q6, a sixth optocoupler circuit OC6, a fifth transistor Q5, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and other adaptively configured resistors and capacitors.

[0097] In this embodiment, the charging of the power battery by the charging gun in the vehicle is simulated by the CC detection circuit 31 and the CP control circuit 32. Specifically, the detection and control of the charging status are achieved through CC (Connection Confirmation) and CP (Control Pilot) signals. When the charging gun is inserted into the vehicle's charging socket, interface J1 receives the CC signal provided by the charging gun. This signal is conditioned and amplified by the second operational amplifier OP2 and then sent to the main control circuit 70. The main control circuit 70 determines whether the charging gun has been reliably connected based on the change in the CC signal and starts the subsequent charging process accordingly. At the same time, the main control circuit 70 outputs a control signal through the SW terminal to drive the transistor Q6 to turn on or off, thereby connecting or disconnecting the fifth resistor R5 in the CP circuit. The fifth resistor R5 is a detection resistor used to simulate the vehicle side, so that the charging gun detects that the vehicle is ready to be charged. At this time, the CP_IN terminal presents a ±12V PWM voltage signal provided by the charging gun, and its duty cycle reflects the maximum allowable charging current. In addition, the main control circuit samples and monitors the CP signal voltage through the CP_VCL_ADC terminal. When the charging gun is not connected or not enabled, the output of the CP_VCL_ADC terminal is approximately 9V. When charging is completed and the detection resistor is connected, the voltage drops to approximately 6V, indicating that the vehicle is in a charging-ready state. Furthermore, the main control circuit 70 can also input control signals through the CP_FRQ terminal to control the CP control circuit 32 to operate / stop.

[0098] Please see Figure 7 In one embodiment of this utility model, the high-voltage interlock circuit 50 includes:

[0099] The high-voltage interlock output circuit 51 is provided with a high-voltage output terminal at one end of the high-voltage connection line connected to the high-voltage connector. The high-voltage interlock output circuit 51 is connected to the main control circuit 70 and is used to output the PWM signal provided by the main control circuit 70 to one end of the high-voltage connection line.

[0100] The high-voltage interlock input circuit 52 is provided with a high-voltage input terminal at the other end of the high-voltage connection line connected to the high-voltage connector. The high-voltage interlock input circuit 52 is connected to the main control circuit 70. The high-voltage interlock input circuit 52 is used to receive the PWM signal input at the other end of the high-voltage connection line, and when it detects that the change in the duty cycle of the PWM signal exceeds the preset range, it outputs an interlock signal to the main control circuit 70.

[0101] In this embodiment, the high-voltage interlock output circuit 51 includes a seventh transistor Q7 and other adaptively configured resistors and capacitors; the high-voltage interlock input circuit 52 includes fifth to seventh diodes, a third operational amplifier OP3, and other adaptively configured resistors and capacitors. The high-voltage interlock output circuit 51 amplifies the PWM signal input from the main control circuit 70 via the HVIL_SW terminal and outputs it to one end of the high-voltage connection line via the HVIL_LINE_OUT terminal. If the high-voltage connector becomes loose or disconnected, the duty cycle of the PWM signal input to the other end of the high-voltage connection line decreases, meaning the duty cycle of the PWM signal input to the HVIL_LINE_IN terminal of the high-voltage interlock input circuit 52 decreases. The high-voltage interlock input circuit 52 can output an interlock signal to the main control circuit 70 when the voltage of the PWM signal does not reach a preset value, so that the main control circuit 70 controls the high-voltage relay to turn off. The high-voltage relay is used to connect / disconnect the high-voltage connection line of the high-voltage connector. Understandably, the high-voltage interlock output circuit 51 can be connected in series with the high-voltage connectors of key high-voltage components such as the power battery pack, high-voltage power distribution unit, inverter, on-board charger, PTC heater, DC-DC converter, and charging interface. If any high-voltage connection point becomes loose, disconnected, or abnormally separated, the high-voltage interlock input circuit 52 outputs an interlock signal to the main control circuit 70. When the main control circuit 70 detects the interlock signal, it immediately controls the high-voltage relay to disconnect, thereby cutting off the high-voltage output of the power battery and preventing arcing, electric shock, or system damage caused by hot plugging or poor contact, thus ensuring the safety of personnel and vehicles.

[0102] Please see Figure 8 In one embodiment of this utility model, the relay control circuit 40 includes a first switching transistor QM1, a second diode D2, a third diode D3, a fourth diode D4, a first fuse F1, a fourth transistor Q4, a first resistor R1, and a second resistor R2.

[0103] In this circuit, the controlled terminal of the first switching transistor QM1 is connected to the first control terminal (LS_ON terminal) of the main control circuit 70. The first terminal of the first switching transistor QM1, the anode of the second diode D2, the cathode of the third diode D3, and the cathode of the fourth diode D4 are connected to one end of the first fuse F1. The second terminal of the first switching transistor QM1, the anode of the third diode D3, and one end of the second resistor R2 are grounded to the emitter of the fourth transistor Q4. The cathode of the second diode D2 is connected to the first power supply terminal of the relay control circuit 40. The anode of the fourth diode D4 and the other end of the second resistor R2 are connected to one end of the first resistor R1. The other end of the first resistor R1 is connected to the base of the fourth transistor Q4. The collector of the fourth transistor Q4 is connected to the second control terminal (LS_VOL terminal) of the main control circuit 70. The other end of the first fuse F1 is connected to the relay (RELAY terminal).

[0104] Understandably, the relay control circuit 40 can also be adapted to include other resistors and capacitors to improve circuit stability.

[0105] In this embodiment, when the main control circuit 70 confirms that the power battery system is normal, it outputs a low level at the LS_VOL terminal, indicating that the relay is allowed to operate. When the control relay is energized, it outputs a high level at the LS_ON terminal, turning on the first switching transistor QM1. Current can flow from the relay RELAY, the first fuse F1, and the first switching transistor QM1 to ground, forming a complete current path. At this time, current flows through the relay coil, and the contacts are energized. When the control relay is de-energized, it outputs a low level at the LS_ON terminal, turning off the first switching transistor QM1, preventing the formation of a current path. At this time, no current flows through the relay coil, and the contacts are de-energized. When the current flowing through the relay is too large, the first fuse F1 blows, breaking the circuit and improving safety.

[0106] This utility model also proposes a teaching device, which includes a battery pack, a circuit to be tested, a charging gun, a relay, a high-voltage connector, and a power battery teaching circuit as described above. The specific structure of the power battery teaching circuit refers to the above embodiments. Since this teaching device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0107] The above description is merely an exemplary embodiment of the present utility model and does not limit the patent scope of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A power battery teaching circuit, characterized in that, include: The acquisition and equalization module is electrically connected to the battery pack and is used to acquire the status information of multiple individual cells in the battery pack. When the voltage difference between multiple individual cells exceeds a preset threshold based on the acquired information, the module performs voltage equalization processing on the multiple individual cells. An electrical testing module, connected to the circuit under test, is used to detect the electrical status information of the circuit under test. The charging detection and control circuit is provided with a charging terminal for connecting the charging gun, and is used to detect and control the charging status of the charging gun. The relay control circuit is provided with control terminals for connecting the relay and for controlling the on and off states of the relay. The high-voltage interlock circuit is equipped with a high-voltage detection terminal for connecting a high-voltage connector, which outputs an interlock signal when an abnormality is detected in the high-voltage connection line of the high-voltage connector; wherein, the interlock signal is used to indicate the disconnection of the high-voltage connection line of the high-voltage connector. The first communication circuit is communicatively connected to the acquisition and equalization module and the electrical detection module, and is also used for communication connection with the host computer. The main control circuit is connected to the charging detection and control circuit, the relay control circuit, the high-voltage interlock circuit, and the first communication circuit, respectively. It is used to control the operation / stop operation of the acquisition and equalization module, the electrical detection module, the charging detection and control circuit, the relay control circuit, and the high-voltage interlock circuit, and to send the status information of multiple individual batteries acquired by the acquisition and equalization module and the electrical status information of the circuit under test detected by the electrical detection module to the host computer through the first communication circuit.

2. The power battery teaching circuit as described in claim 1, characterized in that, The acquisition and equalization module includes: A second communication circuit is communicatively connected to the first communication circuit. Temperature acquisition circuit is used to acquire ambient temperature information of the area where the battery pack is located; A voltage acquisition and equalization circuit is connected to the temperature acquisition circuit and the second communication circuit, respectively, and is provided with voltage acquisition terminals for connecting to each individual cell in the battery pack. The voltage acquisition and equalization circuit is used to acquire the voltage of multiple individual cells, and when the voltage difference between multiple individual cells exceeds a preset threshold, it performs voltage equalization processing on the multiple individual cells. The voltage acquisition and equalization circuit is also used to send equalization information, the voltage of multiple individual cells, and the ambient temperature information acquired by the temperature acquisition circuit to the main control circuit through the second communication circuit, and to operate / stop operating according to the first control signal of the main control circuit.

3. The power battery teaching circuit as described in claim 1, characterized in that, The electrical detection module includes: A third communication circuit is communicatively connected to the first communication circuit. An adhesion detection circuit is provided with an adhesion detection terminal for connecting the circuit to be tested. The adhesion detection circuit is used to detect the adhesion status of the circuit to be tested. A pre-charge detection circuit is provided with a pre-charge detection terminal for connecting to the circuit under test. The pre-charge detection circuit is used to detect the pre-charge voltage of the circuit under test. A leakage current detection circuit is provided with a leakage current detection terminal for connecting to the circuit under test. The leakage current detection circuit is used to detect the resistance value of the circuit under test. A current detection circuit is provided with a current detection terminal for connecting to the circuit under test. The current detection circuit is used to detect the magnitude of the current flowing through the circuit under test. The detection control circuit is connected to the adhesion detection circuit, the pre-charge detection circuit, the leakage detection circuit, and the current detection circuit, respectively. It is used to control the operation of the adhesion detection circuit, the pre-charge detection circuit, the leakage detection circuit, and the current detection circuit, respectively. It also sends the adhesion status, pre-charge voltage, resistance value, and current magnitude of the circuit under test to the main control circuit through the third communication circuit, and is used to start / stop operation according to the second control signal of the main control circuit.

4. The power battery teaching circuit as described in claim 3, characterized in that, The adhesion detection circuit includes a first Zener diode, a second Zener diode, a third Zener diode, a first transformer, a first diode, a first transistor, a second transistor, and a first optocoupler circuit; In this circuit, the negative terminal of the first Zener diode, the first adhesion detection terminal of the adhesion detection circuit, and the negative terminal of the third Zener diode are connected; the positive terminal of the first Zener diode, the second adhesion detection terminal of the adhesion detection circuit, and the positive terminal of the second Zener diode are connected; the first input terminal of the first transformer is connected to the first power supply terminal of the adhesion detection circuit; the second input terminal of the first transformer is grounded; the first output terminal of the first transformer and the positive terminal of the third Zener diode are connected to the first input terminal of the first optocoupler circuit; the second output terminal of the first transformer and the positive terminal of the first diode are connected to the emitter of the first transistor; the negative terminals of the second Zener diode and the first diode are connected to the base of the first transistor; the collector of the first transistor is connected to the second input terminal of the first optocoupler circuit; the first output terminal of the first optocoupler circuit is connected to the second power supply terminal of the adhesion detection circuit; the second output terminal of the first optocoupler circuit is connected to the base of the second transistor; the emitter of the second transistor is grounded; and the collector of the second transistor is connected to the first signal input terminal of the detection control circuit.

5. The power battery teaching circuit as described in claim 3, characterized in that, The pre-charge detection circuit includes a second optocoupler circuit, a third optocoupler circuit, a third transistor, and a first operational amplifier chip; In this circuit, the first output terminal of the second optocoupler circuit is connected to the first pre-charge detection terminal of the pre-charge detection circuit; the first output terminal of the third optocoupler circuit is connected to the second pre-charge detection terminal of the pre-charge detection circuit; the second output terminal of the second optocoupler circuit is connected to the input terminal of the first operational amplifier chip; the second output terminal of the third optocoupler circuit is grounded; the first input terminals of the second and third optocouplers circuits are connected to the power supply terminal of the pre-charge detection circuit; the second input terminals of the second and third optocouplers circuits are respectively connected to the first and second enable terminals of the detection control circuit; the first output terminal of the first operational amplifier chip is connected to the second signal input terminal of the detection control circuit; the second output terminal of the first operational amplifier chip is connected to the base of the third transistor; the emitter of the third transistor is grounded; and the drain of the third transistor is connected to the third signal input terminal of the detection control circuit.

6. The power battery teaching circuit as described in claim 3, characterized in that, The leakage current detection circuit includes a fourth optocoupler circuit, a fifth optocoupler circuit, and a second operational amplifier chip; Specifically, the first output terminal of the fourth optocoupler circuit is connected to the first leakage detection terminal of the leakage detection circuit; the first output terminal of the fifth optocoupler circuit is connected to the second leakage detection terminal of the leakage detection circuit; the second output terminal of the fourth optocoupler circuit is connected to the input terminal of the second operational amplifier chip; the second output terminal of the fifth optocoupler circuit is grounded; the first input terminals of the fourth and fifth optocouplers circuits are connected to the power supply terminal of the leakage detection circuit; the second input terminals of the fourth and fifth optocouplers circuits are respectively connected to the third and fourth enable terminals of the detection control circuit; the first output terminal of the second operational amplifier chip is connected to the fourth signal input terminal of the detection control circuit; and the second output terminal of the second operational amplifier chip is connected to the fifth signal input terminal of the detection control circuit.

7. The power battery teaching circuit as described in claim 1, characterized in that, The charging detection and control circuit includes: The CC detection circuit is provided with a CC detection terminal for connecting the charging gun. The CC detection circuit is connected to the main control circuit. The CC detection circuit is used to detect the charging access status of the charging gun and output a corresponding access status detection signal to the main control circuit. The CP control circuit is provided with a CP control terminal for connecting the charging gun. The CP control circuit is connected to the main control circuit and is used to control the charging state of the charging gun according to the third control signal of the main control circuit.

8. The power battery teaching circuit as described in claim 1, characterized in that, The high-voltage interlock circuit includes: The high-voltage interlock output circuit is provided with a high-voltage output terminal at one end of the high-voltage connection line connected to the high-voltage connector. The high-voltage interlock output circuit is connected to the main control circuit and is used to output the PWM signal provided by the main control circuit to one end of the high-voltage connection line. The high-voltage interlock input circuit is provided with a high-voltage input terminal at the other end of the high-voltage connection line connected to the high-voltage connector. The high-voltage interlock input circuit is connected to the main control circuit. The high-voltage interlock input circuit is used to receive the PWM signal input from the other end of the high-voltage connection line, and when it detects that the change in the duty cycle of the PWM signal exceeds a preset range, it outputs an interlock signal to the main control circuit.

9. The power battery teaching circuit as described in claim 1, characterized in that, The relay control circuit includes a first switching transistor, a second diode, a third diode, a fourth diode, a first fuse, a fourth transistor, a first resistor, and a second resistor; In this circuit, the controlled terminal of the first switching transistor is connected to the first control terminal of the main control circuit; the first terminal of the first switching transistor, the anode of the second diode, the cathode of the third diode, and the cathode of the fourth diode are connected to one end of the first fuse; the second terminal of the first switching transistor, the anode of the third diode, and one end of the second resistor are grounded to the emitter of the fourth transistor; the cathode of the second diode is connected to the first power supply terminal of the relay control circuit; the anode of the fourth diode and the other end of the second resistor are connected to one end of the first resistor; the other end of the first resistor is connected to the base of the fourth transistor; the collector of the fourth transistor is connected to the second control terminal of the main control circuit; and the other end of the first fuse is connected to the relay.

10. A teaching device, characterized in that, The device includes a battery pack, a circuit under test, a charging gun, a relay, a high-voltage connector, and a power battery teaching circuit as described in any one of claims 1 to 9; wherein the battery pack is connected to the acquisition and equalization module, the circuit under test is connected to the electrical detection module, the relay is connected to the charging terminal of the charging detection and control circuit, the relay is connected to the switching terminal of the relay control circuit, and the high-voltage connector is connected to the high-voltage detection terminal of the high-voltage interlock circuit.

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