A power battery pack voltage detection device

Abstract

This invention relates to a power battery pack voltage detection device, comprising a low-voltage control unit, a high-voltage acquisition unit, a signal isolation unit, and a high-voltage switch. The low-voltage control unit includes a microcontroller and a multiplexer. The high-voltage acquisition unit includes an AD sampling module, a signal conditioning module, a shunt acquisition module, a voltage detection module, a positive contactor detection module, a negative contactor detection module, and a high-voltage connector. The microcontroller is connected to the signal isolation unit and the multiplexer. The AD sampling module is connected to the signal isolation unit, the signal conditioning module, and the shunt acquisition module. The high-voltage switch is connected to the signal conditioning module, the voltage detection module, the positive contactor detection module, the negative contactor detection module, and the multiplexer. The high-voltage connector is connected to the shunt acquisition module, the voltage detection module, the positive contactor detection module, and the negative contactor detection module. This device enables high-precision multi-channel high-voltage acquisition and measurement.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle testing technology, and in particular to a power battery pack voltage testing device. Background Technology

[0002] In the high-voltage acquisition unit of an electric vehicle, since the acquisition voltage range of the AD acquisition module is relatively small, the high voltage is usually divided before acquisition. At the same time, considering the safety of the passengers, the high-voltage circuit of the power battery pack and the low-voltage circuit of the vehicle are required to be isolated. This requires the high-voltage acquisition unit to also be isolated from the low-voltage circuit.

[0003] Currently, in the solutions for multi-channel high-voltage measurement of power battery packs, either multiple independent high-voltage acquisition paths are used for separate acquisition, or multiple high-voltage switches are used simultaneously with multiple AD chips to achieve multi-channel high-voltage acquisition. This results in complex system design and high cost. Furthermore, in low-cost designs, due to the small number of high-voltage switches used, there is still a common voltage divider circuit. When using external measuring equipment, this circuit will form a current loop with the measuring equipment's measuring circuit, resulting in a "virtual voltage" displayed on the external measuring equipment, thus leading to incorrect measurement results. Summary of the Invention

[0004] To address the problems of complex design, high cost, and measurement errors caused by "virtual voltage" from external measuring equipment in current multi-channel high-voltage measurement technologies for power battery packs, this invention provides a power battery pack voltage detection device. By optimizing the module structure and principle using a multi-channel control switch, a high-voltage switch—a high-voltage relay / high-voltage optocoupler relay—and a multi-channel AD chip, it achieves high-precision multi-channel high-voltage acquisition and measurement, adhesion detection of multiple positive and negative contactors of the power battery pack, and current acquisition of the shunt. Simultaneously, it meets design requirements with a minimal number of components, reduces PCB layout area, saves system design costs, and achieves optimized system design.

[0005] The technical solution of the present invention is as follows:

[0006] A power battery pack voltage detection device, characterized in that it comprises a low-voltage control unit, a high-voltage acquisition unit, a signal isolation unit, and a high-voltage switch. The low-voltage control unit includes a microcontroller and a multiplexer. The high-voltage acquisition unit includes an AD sampling module, a signal conditioning module, a shunt acquisition module, a voltage detection module, a positive contactor detection module, a negative contactor detection module, and a high-voltage connector. The microcontroller is connected to the signal isolation unit and the multiplexer. The AD sampling module is connected to the signal isolation unit, the signal conditioning module, and the shunt acquisition module. The high-voltage switch is connected to the signal conditioning module, the voltage detection module, the positive contactor detection module, the negative contactor detection module, and the multiplexer. The high-voltage connector is connected to the shunt acquisition module, the voltage detection module, the positive contactor detection module, and the negative contactor detection module.

[0007] The voltage detection module is used to detect the total voltage of the battery pack, and after being reduced to the range recognized by the AD sampling module, it is assigned to the first AD acquisition channel to construct the first high-voltage acquisition circuit. The positive contactor detection module is used to detect the adhesion state of the positive contactor of the battery pack and is assigned to the second AD acquisition channel to construct the second high-voltage acquisition circuit. The negative contactor detection module is used to detect the adhesion state of the negative contactor of the battery pack and is assigned to the third AD acquisition channel to construct the third high-voltage acquisition circuit. The shunt acquisition module is used to acquire the current of the shunt. The multiplexer control switch is used to control the high-voltage switch to connect different high-voltage acquisition circuits. After the signal conditioning module filters out the interference signals of each frequency band, the signal is connected to the AD acquisition channel of the AD sampling module. The AD sampling module sends the AD value read by the AD module to the microcontroller through the signal isolation unit. The microcontroller reads the AD value of the AD sampling module and performs calculations. Based on the relationship between the AD value and the voltage after voltage division and the voltage division ratio, the microcontroller calculates the total voltage value.

[0008] Preferably, the voltage detection module includes a first voltage divider circuit, which includes a first capacitor and a first voltage divider resistor connected in parallel, and a plurality of second voltage divider resistors connected in series in the first AD acquisition channel. The first voltage divider circuit is used to reduce the total voltage of the battery pack. The microcontroller calculates the total voltage value based on the relationship between the AD value of the AD sampling module and the voltage value after voltage division and the voltage division ratio of the first voltage divider circuit.

[0009] Preferably, the positive contactor detection module includes a second voltage divider circuit, which includes a second capacitor and a third voltage divider resistor connected in parallel. The positive contactor detection module is assigned multiple second AD acquisition channels arranged in parallel. The positive contactor detection module also includes multiple fourth voltage divider resistors connected in series in each second AD acquisition channel, and a high-voltage switch is provided in each second AD acquisition channel. The positive contactor detection module controls the high-voltage switches of the multiple second AD acquisition channels to sequentially acquire the voltage changes at the output terminals of multiple positive contactors in order to detect the sticking state of multiple positive contactors.

[0010] Preferably, the negative contactor detection module includes a total voltage acquisition circuit, which includes a third capacitor and a fifth voltage divider resistor connected in parallel, as well as multiple pull-up resistors connected in parallel and then in series. The negative contactor detection module is assigned multiple third AD acquisition channels arranged in parallel. The negative contactor detection module also includes multiple sixth voltage divider resistors connected in series in each of the third AD acquisition channels, and a high-voltage switch is set in each branch of the multiple pull-up resistors in series and in each of the third AD acquisition channels. The midpoint of the voltage divider of the total voltage acquisition circuit is connected to the third AD acquisition channel. The negative contactor detection module controls the high-voltage switches of the multiple third AD acquisition channels to sequentially acquire the voltage changes at the output terminals of multiple negative contactors to detect the sticking state of multiple negative contactors.

[0011] Preferably, the high-voltage switch is a high-voltage relay and / or a high-voltage optocoupler relay.

[0012] Preferably, the signal isolation unit includes a signal isolator and an isolation power supply. The signal isolator is used to transmit communication signals between the AD sampling module and the microcontroller to achieve communication isolation, and the isolation power supply is used to power the high-voltage acquisition unit.

[0013] Preferably, the shunt acquisition module includes a differential input circuit for matching different ranges according to the type and range of the voltage signal acquired by the AD sampling module.

[0014] Preferably, the AD sampling module includes a high-precision AD chip that supports multi-channel acquisition and SPI communication.

[0015] Preferably, the high-precision AD chip is an automotive-grade 16-bit AD chip, model AS8510.

[0016] The technical effects of this invention are as follows:

[0017] This invention relates to a power battery pack voltage detection device, comprising a low-voltage control unit, a high-voltage acquisition unit, a signal isolation unit, and a high-voltage switch. The low-voltage control unit includes a microcontroller and a multiplexer. The high-voltage acquisition unit includes an AD sampling module, a signal conditioning module, a shunt acquisition module, a voltage detection module, a positive contactor detection module, a negative contactor detection module, and a high-voltage connector. The multiplexer controls different high-voltage acquisition circuits to connect to the AD acquisition channel of the AD sampling module after the signal conditioning module filters out interference signals of each frequency band. The AD sampling module outputs the read AD value to the microcontroller, which reads the AD value from the AD sampling module and performs calculations. Simultaneously, the multiplexer can control the on / off state of the high-voltage switch. By controlling the switch to connect the channel to be acquired and disconnect the channel not to be acquired, and by acquiring high-voltage signals from different channels through scanning, the number of AD acquisition channels used can be reduced. Furthermore, the switch can disconnect channels not being acquired, preventing mutual interference caused by shared paths between different high-voltage AD acquisition channels, and avoiding various measurement errors and safety hazards caused by leakage from the high-voltage circuit through a shared path. Because the high-voltage acquisition circuit has a very high voltage, especially before and after the switch is closed, even with a large current-limiting resistor in series, there is still a high potential before the switch is closed. If the switch's withstand voltage is insufficient, it may cause leakage current conduction or even breakdown damage. Therefore, the switches used in this invention are all high-voltage switches with strong withstand voltage and sufficiently large creepage distances between the output and input terminals to prevent high voltage from entering and damaging the control port equipment. This invention utilizes a multi-channel control switch, a high-voltage optocoupler relay, and a high-precision AD chip with multiple AD acquisition channels and SPI communication support to optimize the module structure and principle. This not only achieves high-precision multi-channel high-voltage acquisition, adhesion detection of the positive and negative contactors of the high-voltage battery, and current acquisition of the shunt, but also, due to the simplification and optimization of the module, meets the design functional requirements with the minimum number of components, reduces the PCB layout area, thereby saving system design costs and achieving optimized system design. Attached Figure Description

[0018] Figure 1 This is a structural block diagram of the power battery pack voltage detection device of the present invention.

[0019] Figure 2 This is a schematic diagram of the voltage detection module of the present invention.

[0020] Figure 3 This is a schematic diagram of the positive contactor detection module of the present invention.

[0021] Figure 4 This is a schematic diagram of the negative contactor detection module of the present invention. Detailed Implementation

[0022] The present invention will now be described with reference to the accompanying drawings.

[0023] This invention relates to a power battery pack voltage detection device, the structure of which is as follows: Figure 1 As shown, the system includes a low-voltage control unit, a high-voltage acquisition unit, a signal isolation unit, and a high-voltage switch. The low-voltage control unit includes a microcontroller (MCU) and a multiplexer. The high-voltage acquisition unit includes an AD sampling module, a signal conditioning module, a shunt acquisition module, a voltage detection module, a positive contactor detection module, a negative contactor detection module, and a high-voltage connector. The MCU is connected to the signal isolation unit via a UART bus and to the multiplexer via an I / O bus or a UART bus. The AD sampling module is connected to the signal isolation unit, the signal conditioning module, and the shunt acquisition module, respectively. The signal isolation unit is connected to the AD sampling module via a UART bus. The high-voltage switch is connected to the signal conditioning module, the voltage detection module, the positive contactor detection module, the negative contactor detection module, and the multiplexer. The high-voltage connector is connected to the shunt acquisition module, the voltage detection module, the positive contactor detection module, and the negative contactor detection module, respectively. The voltage detection module detects the total voltage of the battery pack and reduces it to a range recognized by the AD sampling module after voltage division. It is then assigned to the first AD acquisition channel to construct the first high-voltage acquisition circuit. The positive contactor detection module detects the adhesion status of multiple positive contactors in the battery pack and is assigned to the second AD acquisition channel to construct the second high-voltage acquisition circuit. The negative contactor detection module detects the adhesion status of multiple negative contactors in the battery pack and is assigned to the third AD acquisition channel to construct the third high-voltage acquisition circuit. The shunt acquisition module collects the current of the shunt. A multi-channel control switch controls the high-voltage switch to connect different high-voltage acquisition circuits. After the signal conditioning module filters out interference signals in each frequency band, the signals are connected to the AD acquisition channel of the AD sampling module. The AD sampling module outputs the read AD value to the microcontroller (MCU). The MCU reads the AD value from the AD sampling module and performs calculations. Based on the relationship between the AD value and the voltage after voltage division, and the voltage division ratio, it calculates the total voltage value. This enables the acquisition of the total battery pack voltage, detection of adhesion of multiple positive contactors, detection of adhesion of multiple negative contactors, and shunt current detection. Preferably, the signal isolation unit includes a signal isolator and an isolation power supply. The signal isolator is used to transmit communication signals between the AD sampling module and the microcontroller to achieve communication isolation, and the isolation power supply is used to power the high-voltage acquisition unit.

[0024] Because this involves the acquisition of multiple high-voltage signals, to ensure accurate and stable acquisition while minimizing costs, a high-precision AD chip with multiple acquisition channels and SPI communication support was used to optimize the module structure and principle. For the acquisition of the total battery voltage, a dedicated AD acquisition channel was used due to the high speed requirement. For the detection of multiple positive and negative contactor adhesion, since these two functions are identical and the sampling speed requirement is not particularly high, each was assigned a separate AD acquisition channel. Switches were used to connect the channels that needed acquisition and disconnect the channels that did not need acquisition. A scanning acquisition method was then used to acquire the high-voltage signals from different channels, reducing the number of AD acquisition channels used. Disconnecting channels that did not need acquisition by switching prevented mutual interference caused by shared paths between different high-voltage AD acquisition channels, avoiding various measurement errors and safety hazards caused by leakage from the high-voltage circuit through a common circuit.

[0025] It should be noted that because the high-voltage acquisition circuit has a very high voltage, especially before and after the switch is closed, even with a large current-limiting resistor in series, a high potential still exists before the switch is closed. If the switch's withstand voltage is insufficient, leakage current can cause conduction or even breakdown damage. Therefore, the switches used above are all high-voltage switches. It is generally recommended that the withstand voltage of the high-voltage switch be 1.2 to 1.5 times the operating voltage, and the creepage distance between the output and input terminals should be sufficiently large to prevent high voltage from entering and damaging the control port equipment. Furthermore, a multiplexer is used to control the on and off of the high-voltage switch to achieve high-voltage acquisition for different circuits. The multiplexer can be hardwired or URAT bus controlled. The multiplexer can be located within the high-voltage acquisition unit or within the low-voltage control unit. Located within the low-voltage control unit, it reduces the number of digital isolators required.

[0026] Figure 2This is a schematic diagram of the voltage detection module of the present invention. The voltage detection module is essentially a total voltage sampling voltage divider network and signal filtering and conditioning circuit. The voltage detection module includes a first voltage divider circuit and a filtering circuit. The first voltage divider circuit includes a first capacitor and a first voltage divider resistor connected in parallel, and multiple second voltage divider resistors connected in series in the first AD acquisition channel. The measurement principle is to reduce the high total voltage of the battery pack to a range recognizable by the AD chip in the AD sampling module through the first voltage divider circuit. The voltage is then processed by the signal conditioning module to filter out interference signals in various frequency bands, improve the anti-interference capability of the acquired signal, and ensure the accuracy and stability of voltage acquisition. The processed voltage is then input to the AD chip, which outputs the read AD value to the microcontroller (MCU). The MCU reads the AD value from the AD chip and calculates the total voltage value of the battery pack based on the relationship between the AD value and the voltage value after voltage division and the voltage division ratio of the voltage divider circuit. The filtering circuit is used to filter the total voltage signal input from the negative terminal. The total voltage value of the battery pack is calculated according to the following formula:

[0027]

[0028] Where: K is the voltage division coefficient of the voltage divider resistor, AD is the AD value acquired by the AD chip, and V REF Where is the reference voltage of the AD chip, and G is the voltage amplification factor of the AD chip.

[0029] Preferably, the high-precision AD chip model selected is the automotive-grade 16-bit AD chip AS8510.

[0030] In the first AD acquisition channel, a high-voltage switch S+ is provided at the high-voltage signal input port of the high-voltage connector, and a high-voltage switch S- is provided at the high-voltage signal output port of the high-voltage connector. It is understood that the high-voltage switch can also be placed between the first and second voltage-dividing resistors, which can limit the current of multiple series-connected second voltage-dividing resistors and improve the safety of the high-voltage switch. Furthermore, when the acquisition voltage is not needed, the high-voltage switch can cut off the resistor circuit of the sampling module, thereby eliminating battery losses caused by sampling through the acquisition resistors. Preferably, the high-voltage switch is a high-voltage relay and / or a high-voltage optocoupler relay.

[0031] Figure 3This is a schematic diagram of the positive contactor detection module of the present invention. The positive contactor detection module is essentially a positive contactor adhesion detection sampling voltage divider network. The positive contactor detection module includes a second voltage divider circuit, which includes a second capacitor and a third voltage divider resistor connected in parallel. The positive contactor detection module is assigned multiple (N in this embodiment) second AD acquisition channels arranged in parallel. The positive contactor detection module also includes multiple fourth voltage divider resistors connected in series in each second AD acquisition channel, and a high-voltage switch (S1, S2...S...) is provided in each second AD acquisition channel. N The detection principle of this positive contactor detection module is to determine the contactor's state by collecting voltage changes at the input and output terminals of the positive contactor. Essentially, it measures a high-voltage signal, similar to the principle used by the voltage detection module for detecting the total voltage of the battery pack. The difference lies in that this positive contactor detection module uses multiple second AD acquisition channels to collect voltage signals and input them to a shared signal conditioning module and AD chip. The microcontroller (MCU) controls one of the second AD acquisition channels to conduct, while simultaneously controlling the high-voltage switches of the other channels to deactivate, thus cutting off the input signals from those channels. This allows only the signal from that specific second AD acquisition channel to be collected and judged, ensuring that only one channel is used for acquisition in each process. By cyclically controlling the switches of different channels to connect to the signal conditioning module and AD chip, filtering and acquisition of signals from all channels can be achieved. The positive contactor detection module also detects the adhesion status of multiple positive contactors by controlling the high-voltage switches of multiple second AD acquisition channels to sequentially collect voltage changes at the output terminals of multiple positive contactors. Furthermore, since multiple second AD acquisition channels share the same signal conditioning module and AD chip, the number of signal conditioning modules and AD chips can be effectively reduced, greatly lowering the cost.

[0032] Understandably, the high-voltage switch is positioned between the third and fourth voltage divider resistors. Alternatively, it can be placed on the high-voltage signal input port of the high-voltage connector. This serves to limit the current through the series resistors and provide some protection for the switch, significantly reducing the impact of the input high voltage on the switch and making it safer.

[0033] Figure 4This is a schematic diagram of the negative contactor detection module of the present invention. The negative contactor detection module is essentially a negative contactor adhesion detection sampling voltage divider network. The negative contactor detection module includes a total voltage acquisition circuit, which includes a third capacitor and a fifth voltage divider resistor connected in parallel, as well as multiple pull-up resistors connected in parallel and then in series. The negative contactor detection module is assigned multiple (N in this embodiment) third AD acquisition channels arranged in parallel. The negative contactor detection module also includes multiple sixth voltage divider resistors connected in series in each third AD acquisition channel, and a high-voltage switch S+ is set in the branch of the multiple pull-up resistors connected in series. Each third AD acquisition channel is also equipped with a high-voltage switch (S1, S2...S...). N The midpoint of the voltage divider in the total voltage acquisition circuit is connected to the third AD acquisition channel. The detection principle is to determine the sticking state of the negative contactor by sequentially acquiring the voltage changes before and after the negative contactor is closed and opened through multiple third AD acquisition channels. Specifically, the negative contactor is in a floating state before closing and in a zero-voltage state after closing. In order to detect the zero-voltage state, a series pull-up resistor is added to the total voltage acquisition circuit to pull the voltage in the above state to the total positive voltage. Simultaneously, a high-voltage switch is designed for each third AD acquisition channel. The high-voltage switch selects the channel to be detected. Once the channel is selected, if the negative contactor for that channel is not closed, the voltage value acquired by the AD chip is constant. If the negative contactor is closed, the resistor at the channel port is connected to the negative terminal, changing the resistance of the total voltage acquisition circuit and consequently altering the voltage acquired by the AD chip. Therefore, by observing the voltage changes of the corresponding third AD acquisition channel before and after the negative contactor closes or opens, and by sequentially acquiring the voltage changes at the output terminals of multiple negative contactors through multiple third AD acquisition channels, the sticking status of multiple negative contactors can be detected. Furthermore, since the pull-up resistor of the total voltage acquisition circuit and the required total positive voltage input are also controlled by the high-voltage switch, to prevent the sampling resistor from consuming battery power, both can share a single high-voltage switch. This reduces the number of high-voltage switches and lowers costs.

[0034] It should be noted that the multiple series-connected sixth voltage divider resistors in each of the above-mentioned third AD acquisition channels cannot be shared with the pull-up resistor added to the total voltage acquisition circuit. The multiple series-connected sixth voltage divider resistors in each third AD acquisition channel must be used independently with the pull-up resistor.

[0035] Understandably, the negative contactor detection module also uses multiple third AD acquisition channels that share the same signal conditioning module and AD chip, which can effectively reduce the number of signal conditioning modules and AD chips and greatly reduce costs.

[0036] Preferably, the shunt acquisition module includes a differential input circuit, which can match different ranges according to the type and range of the voltage signal acquired by the AD chip.

[0037] This invention provides a power battery pack voltage detection device. By optimizing the module structure and principle using a multi-channel control switch, a high-voltage optocoupler relay, and a multi-channel AD chip, it can achieve high-precision multi-channel high-voltage acquisition, detection of adhesion of the positive and negative contactors of the high-voltage battery pack, and current acquisition of the shunt. At the same time, due to the simplification and optimization of the module, the design requirements are achieved with the minimum number of components, reducing the PCB layout area, saving system design costs, and realizing optimized system design.

[0038] It should be noted that the specific embodiments described above enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. Therefore, although the present invention has been described in detail with reference to the accompanying drawings and embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention. In short, all technical solutions and improvements that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention patent.

Claims

1. A power battery pack voltage detection device, characterized in that, The application relates to a battery pack voltage detection device, which comprises a low-voltage control unit, a high-voltage acquisition unit, a signal isolation unit and a high-voltage switch, wherein the low-voltage control unit comprises a microcontroller and a multipath control switch, the high-voltage acquisition unit comprises an AD sampling module, a signal conditioning module, a shunt acquisition module, a voltage detection module, a positive contactor detection module, a negative contactor detection module and a high-voltage connector, the microcontroller is connected with the signal isolation unit and the multipath control switch respectively, the AD sampling module is connected with the signal isolation unit, the signal conditioning module and the shunt acquisition module respectively, the high-voltage switch is connected with the signal conditioning module, the voltage detection module, the positive contactor detection module, the negative contactor detection module and the multipath control switch respectively, and the high-voltage connector is connected with the shunt acquisition module, the voltage detection module and the positive contactor detection module respectively, The voltage detection module is used for detecting the total voltage of the battery pack, and the total voltage is reduced through voltage division to the range recognized by the AD sampling module and is distributed to a first AD acquisition channel to construct a first high-voltage acquisition loop; the positive contactor detection module is used for detecting the adhesion state of the positive contactor of the battery pack and is distributed to a second AD acquisition channel to construct a second high-voltage acquisition loop; the negative contactor detection module is used for detecting the adhesion state of the negative contactor of the battery pack and is distributed to a third AD acquisition channel to construct a third high-voltage acquisition loop; the shunt acquisition module is used for acquiring the current of the shunt; the multipath control switch is used for controlling the high-voltage switch to connect different high-voltage acquisition loops; after interference signals of various frequency bands are filtered through the signal conditioning module, the AD acquisition channel of the AD sampling module is accessed; the AD value read by the AD sampling module is sent to the microcontroller through the signal isolation unit; the microcontroller reads the AD value of the AD sampling module and performs calculation; the voltage value of the total voltage is calculated according to the relationship between the AD value and the voltage after voltage division and the voltage division ratio of voltage division; The voltage detection module comprises a first voltage division circuit, the first voltage division circuit comprises a first capacitor and a first voltage division resistor connected in parallel, and a plurality of second voltage division resistors connected in series are arranged in the first AD acquisition channel; The positive contactor detection module comprises a second voltage division circuit, the second voltage division circuit comprises a second capacitor and a third voltage division resistor connected in parallel, and a plurality of fourth voltage division resistors connected in series are arranged in each second AD acquisition channel; The negative contactor detection module comprises a total voltage acquisition circuit, the total voltage acquisition circuit comprises a third capacitor and a fifth voltage division resistor connected in parallel, and a plurality of pull-up resistors connected in series after being connected in parallel.

2. The power battery pack voltage detection device according to claim 1, characterized in that, The first voltage division circuit is used for reducing the total voltage of the battery pack, and the voltage value of the total voltage is calculated by the microcontroller according to the relationship between the AD value of the AD sampling module and the voltage value after voltage division and the voltage division ratio of the first voltage division circuit.

3. The power battery pack voltage detection device according to claim 1, characterized in that, The positive electrode contactor detection module is assigned a plurality of second AD acquisition channels arranged in parallel, and one high-voltage switch is arranged in each second AD acquisition channel; the positive electrode contactor detection module acquires voltage changes of output ends of a plurality of positive electrode contactors in sequence by controlling high-voltage switches of a plurality of second AD acquisition channels, so as to detect the sticking state of the plurality of positive electrode contactors.

4. The power battery pack voltage detection device according to claim 1, characterized in that, The negative electrode contactor detection module is assigned a plurality of third AD acquisition channels arranged in parallel, and the negative electrode contactor detection module further comprises a plurality of sixth voltage dividing resistors arranged in series in each third AD acquisition channel, and one high-voltage switch is arranged in each branch of the plurality of pull-up resistors arranged in series and each third AD acquisition channel; a voltage dividing midpoint of the total voltage acquisition circuit is connected with the third AD acquisition channel; the negative electrode contactor detection module acquires voltage changes of output ends of a plurality of negative electrode contactors in sequence by controlling high-voltage switches of a plurality of third AD acquisition channels, so as to detect the sticking state of the plurality of negative electrode contactors.

5. The power battery pack voltage detection device according to claim 2, characterized in that, The high-voltage switch is a high-voltage relay and / or a high-voltage optocoupler relay.

6. The power battery pack voltage detection apparatus according to claim 1, wherein The signal isolation unit comprises a signal isolator and an isolation power supply; the signal isolator is used to transmit communication signals of the AD sampling module and the microcontroller, so as to realize communication isolation; and the isolation power supply is used to supply power for the high-voltage acquisition unit.

7. The power battery pack voltage detection device according to claim 1, characterized in that, The shunt collector acquisition module comprises a differential input circuit, which is used to match different ranges according to the type and range of voltage signals collected by the AD sampling module.

8. The power battery pack voltage detection apparatus according to claim 1, wherein The AD sampling module comprises a high-precision AD chip, which supports multi-channel acquisition and SPI communication.

9. The power battery pack voltage detection apparatus according to claim 8, wherein The high-precision AD chip adopts a chip of model AS8510 of a car level 16-bit AD chip. The high-precision AD chip adopts a chip of model AS8510 of a car level 16-bit AD chip.

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