A high-voltage loop acquisition system and a detection method of a high-voltage loop system

Abstract

The application discloses a high-voltage loop acquisition system and a detection method of a high-voltage loop system. The high-voltage loop acquisition system comprises N acquisition modules and an operation module. The first end of each acquisition module is connected with a high-voltage reference ground, and the second end is connected with a corresponding to-be-detected node, for acquiring an electric signal of each to-be-detected node relative to the high-voltage reference ground. The high-voltage reference ground is connected with the first pole of a battery pack. The operation module is used for generating at least one of a differential voltage value between each to-be-detected node and a relative voltage value between each to-be-detected node and the high-voltage reference ground based on each electric signal. The to-be-detected node at least comprises the first pole of a busbar, the second pole of the busbar, the second pole of the battery pack and a heating film positive end node. According to the embodiment of the application, the acquisition and calculation of the multi-point voltage in the high-voltage loop can be realized without increasing the high-voltage isolation device.

Description

Technical Field

[0001] This application belongs to the field of power electronics technology, and in particular relates to a high-voltage circuit acquisition system and a detection method for the high-voltage circuit system. Background Technology

[0002] In high-voltage circuit acquisition schemes for battery packs, differential acquisition typically employs a dual-ground isolation architecture, requiring two independent high-voltage grounds and isolated power supplies, or the use of dedicated isolation differential chips, resulting in complex circuitry and high costs. Negative voltage detection requires additional high-voltage negative power supplies or bipolar power supplies, leading to significant hardware overhead. Furthermore, the high-voltage divider network continuously generates static leakage current in sleep mode, affecting the battery's idle lifespan. These issues are particularly prominent during the evolution of BMS towards an 800V high-voltage platform. Traditional, independently implemented solutions suffer from circuit stacking, component redundancy, and high costs, making it difficult to meet the requirements for low-cost, highly integrated acquisition.

[0003] In view of this, it is indeed necessary to provide a solution that can achieve multi-point voltage acquisition in a high-voltage circuit without adding high-voltage isolation devices. Summary of the Invention

[0004] This application provides a high-voltage circuit acquisition system and a high-voltage circuit system detection method, which can realize the acquisition and calculation of multi-point voltage in a high-voltage circuit without adding high-voltage isolation devices.

[0005] In a first aspect, embodiments of this application provide a high-voltage circuit acquisition system, comprising: There are N acquisition modules. The first end of each acquisition module is connected to the high-voltage reference ground, and the second end of each acquisition module is connected to the corresponding node under test. They are used to acquire the electrical signal of each node under test relative to the high-voltage reference ground. Here, N is a positive integer, and the high-voltage reference ground is connected to the first pole of the battery pack. The arithmetic module is used to generate at least one of the differential voltage values ​​between each node under test and the relative voltage values ​​between each node under test and the high voltage reference ground, based on the electrical signals of each node under test relative to the high voltage reference ground. The node to be tested includes at least the first pole of the busbar, the second pole of the busbar, the second pole of the battery pack, and the positive terminal node of the heating film. The positive terminal node of the heating film is the high-voltage node between the heating relay and the heating film. The heating relay is located between the first pole and the second pole of the busbar.

[0006] In some possible implementations, each acquisition module includes a first voltage divider network, an acquisition unit, a switching unit, and a second voltage divider network; The first voltage divider network includes one or more resistors connected in series. The first end of the first voltage divider network is connected to the second end of the switching unit, and the second end of the first voltage divider network is connected to the corresponding node under test. The first voltage divider network is used to divide the voltage between each node under test and the switching unit. The first terminal of the switching unit is connected to the second terminal of the second voltage divider network and the second terminal of the acquisition unit, respectively. The first terminal of the second voltage divider network is connected to the high voltage reference ground. The second voltage divider network includes one or more resistors connected in series. The second voltage divider network is used to divide the voltage between the switching unit and the high voltage reference ground. The acquisition unit is located between the switching unit and the second voltage divider network. The acquisition unit is connected to the computing module. The acquisition unit is used to acquire the electrical signals between each node under test and the high voltage reference ground, and transmit the electrical signals to the computing module.

[0007] In some possible implementations, the N acquisition modules include a common negative terminal acquisition module, the first terminal of which is connected to the high voltage reference ground, and the second terminal of which is connected to the first pole of the bus. The acquisition unit in the common negative terminal acquisition module is used to acquire the common negative terminal electrical signal and transmit the common negative terminal electrical signal to the arithmetic module. The common negative terminal electrical signal is used to characterize the voltage of the first pole of the bus relative to the high voltage reference ground.

[0008] In some possible implementations, the N acquisition modules include a busbar positive end acquisition module, the first end of which is connected to the high voltage reference ground, and the second end of which is connected to the second pole of the busbar. The acquisition unit of the bus positive terminal acquisition module is used to acquire the bus positive terminal electrical signal and transmit the bus positive terminal electrical signal to the arithmetic module. The bus positive terminal electrical signal is used to characterize the voltage of the second pole of the bus relative to the high voltage reference ground. The arithmetic module is used to perform differential calculations on the positive terminal electrical signal of the bus and the common negative terminal electrical signal to generate an external total differential voltage value. The external total differential voltage value is used to characterize the voltage between the first pole and the second pole of the bus.

[0009] In some possible implementations, the N acquisition modules include a battery pack positive electrode acquisition module, the second end of which is connected to the second electrode of the battery pack, and the first end of which is connected to the high voltage reference ground. The acquisition unit of the battery pack positive terminal acquisition module is used to acquire the battery pack positive terminal electrical signal and transmit the battery pack positive terminal electrical signal to the computing module. The battery pack positive terminal electrical signal is used to characterize the voltage of the second terminal of the battery pack relative to the high voltage reference ground. The calculation module is used to calculate the potential of the positive terminal electrical signal of the battery pack and the high voltage reference ground to generate the total voltage value inside the battery pack.

[0010] In some possible implementations, the N acquisition modules include a bus auxiliary positive terminal acquisition module, the second end of which is connected to the second pole of the bus, and the first end of which is connected to the high voltage reference ground. The acquisition unit in the bus auxiliary positive terminal acquisition module is used to acquire the bus auxiliary positive terminal electrical signal and transmit the bus auxiliary positive terminal electrical signal to the calculation module. The bus auxiliary positive terminal electrical signal is used to characterize the voltage of the second pole of the bus relative to the high voltage reference ground. The calculation module is used to calculate the potential of the bus auxiliary positive terminal electrical signal and the high voltage reference ground to generate the bus auxiliary external total voltage value.

[0011] In some possible implementations, the N acquisition modules include a heating film positive terminal acquisition module, the second terminal of which is connected to a heating relay, and the first terminal of which is connected to a high voltage reference ground. The acquisition unit in the heating film positive terminal acquisition module is used to acquire the heating film positive terminal electrical signal and transmit the heating film positive terminal electrical signal to the calculation module. The heating film positive terminal electrical signal is used to characterize the voltage of the heating relay relative to the high voltage reference ground. The arithmetic module is used to perform differential calculations on the electrical signal at the positive terminal of the heating film and the electrical signal at the common negative terminal to generate differential voltage values ​​at both ends of the heating film.

[0012] In some possible implementations, the N acquisition modules include a common negative terminal acquisition module and a bus positive terminal acquisition module; The system also includes a bias module and a reference voltage source; The bias module is located between the reference voltage source and the high voltage reference ground. The bias module includes a bias node. The first ends of the common negative terminal acquisition module and the bus positive terminal acquisition module are both connected to the high voltage reference ground through the bias node. The bias module is used to provide common-mode DC bias voltage to the common negative terminal acquisition module and the bus positive terminal acquisition module, respectively.

[0013] In some possible implementations, the bias module includes at least h1 first bias resistors and h2 second bias resistors, wherein the total resistance of h1 first bias resistors is equal to the total resistance of h2 second bias resistors, and h1 and h2 are both positive integers. h1 first bias resistors are connected in series between the reference voltage source and the bias node, the second end of h1 first bias resistors is connected to the reference voltage source, and the first end of h1 first bias resistors is connected to the bias node. h2 second bias resistors are connected in series between the bias node and the high-voltage reference ground. The second end of h2 second bias resistors is connected to the bias node, and the first end of h2 second bias resistors is connected to the high-voltage reference ground.

[0014] Based on the same inventive concept, in a second aspect, embodiments of this application provide a detection method for a high-voltage circuit system. The high-voltage circuit system includes a high-voltage circuit acquisition system, a main positive relay, a main negative relay, a pre-charge branch, and a heating relay. The high-voltage circuit acquisition system includes N acquisition modules and a calculation module. The first end of each acquisition module is connected to a high-voltage reference ground, and the second end of each acquisition module is connected to the corresponding node under test. The high-voltage reference ground is connected to the first pole of the battery pack. The node under test includes at least the first pole of the busbar, the second pole of the busbar, the second pole of the battery pack, and a heating film positive terminal node. The heating film positive terminal node is a high-voltage node between the heating relay and the heating film. The heating relay is located between the first pole and the second pole of the busbar, where N is a positive integer. Among them, the main positive relay and the pre-charge branch are connected in parallel between the second pole of the bus and the second pole of the battery pack. The pre-charge branch includes a pre-charge relay and a pre-charge resistor connected in series. The main negative relay is connected between the first pole of the battery pack and the first pole of the bus. The heating relay is located between the first pole of the bus and the second pole of the bus. The detection method includes: Acquire electrical signals of N nodes under test relative to the high-voltage reference ground; Based on the electrical signal of each node under test relative to the high-voltage reference ground, at least one of the differential voltage value between each node under test and the relative voltage value between each node under test and the high-voltage reference ground is generated. The electrical state of the high-voltage circuit is determined based on at least one of the differential voltage value and the relative voltage value.

[0015] In some possible implementations, the electrical state includes the bus positive circuit relay sticking state; Determine the electrical condition of the high-voltage circuit, including: When the main positive relay, precharge relay and main negative relay are all disconnected, the reference electrical signal of the common negative terminal is determined based on the electrical signal of the first pole of the bus relative to the high voltage reference ground. The external total differential voltage value is generated based on the electrical signal of the second pole of the bus relative to the high voltage reference ground and the common negative terminal reference electrical signal. The total voltage within the battery pack is determined based on the electrical signal of the second terminal of the battery pack relative to the high-voltage reference ground. If the difference between the external total differential voltage and the total voltage inside the battery pack is greater than or equal to a preset difference threshold, it is determined that at least one of the main positive relay and the precharge relay is stuck together.

[0016] In some possible implementations, the electrical state includes the bus negative circuit relay sticking state; Determine the electrical condition of the high-voltage circuit, including: When the main positive relay is open, the precharge relay is closed, and the main negative relay is open, the reference electrical signal of the common negative terminal is determined based on the electrical signal of the first pole of the bus relative to the high voltage reference ground. A differential voltage value is generated based on the electrical signal of the second terminal of the battery pack relative to the high voltage reference ground and the reference electrical signal of the common negative terminal. If the differential voltage value is greater than the first preset voltage threshold, it is determined that the main negative relay has stuck.

[0017] In some possible implementations, the electrical state includes the heating branch relay sticking state; Determine the electrical condition of the high-voltage circuit, including: When the main positive relay is open, the precharge relay is closed, the main negative relay is closed, and the heating relay is open, the reference electrical signal of the common negative terminal is determined based on the electrical signal of the first pole of the bus relative to the high voltage reference ground. Based on the electrical signal of the heating relay relative to the high voltage reference ground and the common negative terminal reference electrical signal, a differential voltage value is generated across the heating film. The external total differential voltage value is generated based on the electrical signal of the second pole of the bus relative to the high voltage reference ground and the common negative terminal reference electrical signal. If the difference between the differential voltage value at both ends of the heating film and the total differential voltage value is greater than or equal to the second preset voltage threshold, it is determined that the heating relay has stuck.

[0018] This application provides a high-voltage loop acquisition system and a detection method for the high-voltage loop system. By setting up N acquisition modules connected to the same high-voltage reference ground, and using a computing module to generate differential voltage values ​​and relative voltage values ​​based on the electrical signals of each node under test relative to the high-voltage reference ground, it is not necessary to configure independent high-voltage isolation grounds and isolated power supplies for each differential channel. This eliminates the need for dedicated isolation differential chips and a second isolation power supply, thereby reducing the number of isolation devices and high-voltage side power supply lines at the hardware level, and lowering material costs and PCB layout complexity. At the same time, since the acquisition modules directly output the electrical signals of each node relative to the same reference ground, the computing module can flexibly reconstruct the differential relationship between any nodes, so that adding new acquisition channels does not require building negative-end isolation branches, and expansion costs are effectively controlled. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a high-voltage circuit acquisition system provided in one embodiment of this application; Figure 2 This is a schematic diagram of the structure of a data acquisition module in a high-voltage circuit data acquisition system according to another embodiment of this application; Figure 3 This is a schematic diagram of the structure of a high-voltage circuit acquisition system provided in another embodiment of this application; Figure 4 This is a schematic diagram of the structure of a high-voltage circuit acquisition system provided in another embodiment of this application; Figure 5 This is a schematic diagram of the structure of a high-voltage circuit acquisition system provided in another embodiment of this application; Figure 6 This is a schematic diagram of the structure of a high-voltage circuit acquisition system provided in another embodiment of this application; Figure 7 This is a schematic diagram of the structure of a high-voltage circuit acquisition system provided in another embodiment of this application; Figure 8 This is a schematic diagram of the structure of a high-voltage circuit acquisition system provided in another embodiment of this application; Figure 9 This is a schematic diagram of the structure of a high-voltage circuit acquisition system provided in another embodiment of this application; Figure 10 This is a schematic diagram of the structure of a high-voltage circuit acquisition system provided in another embodiment of this application; Figure 11 This is a flowchart illustrating a detection method for a high-voltage circuit system provided in another embodiment of this application.

[0021] In the attached image: 1000. High-voltage circuit system; 100. High-voltage circuit acquisition system; 110. Acquisition module; 111. First voltage divider network; 112. Acquisition unit; 113. Switching unit; 1131. Optocoupler; 1132. Optocoupler primary-side current-limiting resistor; 1133. Low-voltage side system power supply; 114. Second voltage divider network; 115. Acquisition current-limiting resistor; 120. Calculation module; 1101 Common negative terminal acquisition module; 1102 Bus positive terminal acquisition module; 1103 Battery pack positive terminal acquisition module; 1104 Bus auxiliary positive terminal acquisition module; 1105 Heating film positive terminal acquisition module; 200, Main positive relay; 300, Pre-charge branch; 301, Pre-charge relay; 302, Pre-charge resistor; 400, Heating relay; 500, Heating film resistor; 600, Bias module; 601, Bias node; 602, First bias resistor; 603, Second bias resistor; 700, Reference voltage source; 800, Main negative relay; GND, High voltage reference ground; PACK+, Second terminal of battery pack; LINK+, Second terminal of bus; LINK-, First terminal of bus; N i1. Node under test; EN, enable signal; D1, LED. Detailed Implementation

[0022] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0023] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0024] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0025] In the embodiments of this application, the term "electrical connection" can refer to a direct electrical connection between two components, or it can refer to an electrical connection between two components via one or more other components.

[0026] Various modifications and variations can be made to this application without departing from its spirit or scope, which will be apparent to those skilled in the art. Therefore, this application is intended to cover modifications and variations falling within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the implementation methods provided in the embodiments of this application can be combined with each other without contradiction.

[0027] Before describing the technical solutions provided in the embodiments of this application, in order to facilitate understanding of the embodiments of this application, this application first specifically explains the problems existing in the related technologies: As mentioned earlier, in the high-voltage platform of new energy vehicles, the battery management system typically needs to acquire voltage data from multiple nodes on the battery pack and high-voltage bus. Traditional solutions for achieving differential acquisition of the external total voltage usually require configuring independent high-voltage reference grounds for the positive and negative terminals, and performing differential calculations on each signal on the low-voltage side; or using dedicated isolated differential amplifier chips to directly output the differential results. These methods suffer from problems such as complex circuit structures, difficult printed circuit board wiring, and high overall hardware costs.

[0028] To address the aforementioned technical problems, this application provides a high-voltage circuit acquisition system. The following first combines... Figure 1 The high-voltage circuit acquisition system 100 of this application embodiment will be described.

[0029] Figure 1 This is a schematic diagram of the structure of a high-voltage circuit acquisition system 100 provided in an embodiment of this application.

[0030] like Figure 1 As shown, this application embodiment provides a high-voltage circuit acquisition system 100, including: N acquisition modules 110 and a processing module 120; There are N data acquisition modules 110. The first terminal of each data acquisition module 110 is connected to the high-voltage reference ground GND, and the second terminal of each data acquisition module 110 is connected to the corresponding node under test N. i Connections are used to collect data from each node N under test. i The electrical signal relative to the high voltage reference ground GND, where N is a positive integer, and the high voltage reference ground GND is connected to the first terminal of the battery pack; The calculation module 120 is used to calculate the results based on each node N under test. i The electrical signal relative to the high-voltage reference ground GND is used to generate the N signals for each node under test. i The differential voltage values ​​between and each measured node N i At least one of the relative voltage values ​​between the voltage reference ground (GND) and the high voltage reference ground (GND); Among them, the node to be tested N i It includes at least the first pole of the busbar, the second pole of the busbar, the second pole of the battery pack, and the positive terminal node of the heating film.

[0031] In this application, the aforementioned high-voltage reference ground GND serves as a unified potential reference for the entire system, and it is connected to the first terminal PACK- of the battery pack. The battery pack can be, for example, a power battery pack that provides power to the high-voltage circuit. The first terminal of the battery pack can be, for example, the negative terminal of the battery pack, i.e., the PACK- node, and the second terminal of the battery pack can be, for example, the positive terminal of the battery pack, i.e., the PACK+ node. In one example, for a power battery pack with a nominal voltage of 400V, if the negative terminal of the battery pack is used as the high-voltage reference ground, then the potential of the positive terminal of the battery pack relative to the high-voltage reference ground is approximately 400V. It should be noted that the first and second terminals in the embodiments of this application are only used to distinguish the two electrodes of the battery pack or busbar, and do not limit the specific polarity of the two electrodes; in other embodiments, the first terminal of the battery pack can also be the positive terminal, and the second terminal of the battery pack can also be the negative terminal, in which case the operating modes of each acquisition module 110 and the processing module 120 can be adjusted accordingly.

[0032] The above-mentioned node N to be tested i This refers to the electrical node in the high-voltage circuit that requires voltage acquisition. In this embodiment, the node to be measured is N. i It includes at least the first terminal of the busbar, the second terminal of the busbar, the second terminal of the battery pack, and the positive terminal of the heating film. The first terminal of the busbar is one electrode of the busbar, for example, the negative terminal (LINK-); the second terminal of the busbar is the other electrode of the busbar, for example, the positive terminal (LINK+). The busbar can be, for example, a DC busbar connecting the battery pack to an external load or charging interface. For instance, in a high-voltage circuit system including a power battery pack and a DC busbar, the node under test can be the positive terminal of the battery pack, the positive terminal of the busbar, and the negative terminal of the busbar, while the high-voltage reference ground is the negative terminal of the battery pack.

[0033] The aforementioned electrical signals are acquired by each acquisition module 110 and are used to characterize the corresponding node N under test. i A signal relative to the potential of the high-voltage reference ground GND. This electrical signal can be, for example, a voltage signal, the amplitude of which is related to the potential of the corresponding node N under test. i This corresponds to the potential of the high-voltage reference ground GND. It should be noted that the electrical signal can be relative to the node under test N. i The signal corresponding to the potential equivalent can also be the signal corresponding to the node N to be measured. i The application does not limit the signal to be proportional to the potential, as long as the electrical signal can reflect the corresponding node N under test. i The potential relative to the high-voltage reference ground GND is sufficient.

[0034] The aforementioned N acquisition modules 110 are used to acquire data from each node N to be tested. iThe electrical signal is relative to the high-voltage reference ground GND, where N is a positive integer. The first terminal of each acquisition module 110 is connected to the high-voltage reference ground GND, and the second terminal of each acquisition module 110 is connected to a corresponding node under test N. i The connection allows all acquisition modules 110 in the entire system to share the same potential reference, namely the high-voltage reference ground GND.

[0035] For example, when the node to be tested N i When there are four nodes—the positive terminal of the battery pack, the positive terminal of the busbar, the negative terminal of the busbar, and the positive terminal of the heating film—N can be 4. This means four acquisition modules are set up, each connected to one of the four nodes (battery pack positive, busbar positive, busbar negative, and heating film positive) to acquire the electrical signals of each node relative to the high-voltage reference ground. It should be noted that since the nodes under test include at least the first and second terminals of the busbar, the second terminal of the battery pack, and the positive terminal of the heating film, N must be at least 4. When it is necessary to expand the acquisition to include other nodes, the value of N can be increased accordingly.

[0036] The aforementioned processing module 120 is connected to each acquisition module 110 and is used to receive the electrical signals acquired by each acquisition module 110, and to perform calculations based on each node under test N. i The electrical signal relative to the high-voltage reference ground GND is used to generate the N signals for each node under test. i The differential voltage values ​​between and each measured node N i At least one of the relative voltage values ​​between the processor and the high-voltage reference ground GND. The processing module may be a device with signal processing capabilities, such as a microcontroller unit (MCU), a digital signal processor (DSP), or a dedicated processing circuit, and this application does not limit it in this regard.

[0037] The differential voltage value is the voltage difference between the two nodes under test, obtained by performing a differential operation on the relative voltage values ​​of the two nodes under test relative to the high-voltage reference ground GND. The relative voltage value is the voltage difference between node N and the node under test. i The voltage value between the high-voltage reference ground (GND) and the voltage level; since the high-voltage reference ground (GND) is used as a zero-potential reference, the voltage value between the node under test (N) and the reference ground (GND) is... i The relative voltage value between the node and the high-voltage reference ground GND is equal to that of the node under test N. i The electrical signal itself relative to the high-voltage reference ground GND.

[0038] Specifically, when performing high-voltage data acquisition, we will use the following example: the first busbar terminal corresponds to the negative busbar terminal, the second busbar terminal corresponds to the positive busbar terminal, the second battery pack terminal corresponds to the positive battery pack terminal, and the high-voltage reference ground (GND) corresponds to the negative battery pack terminal. For ease of description, let the electrical signal of the positive busbar terminal relative to the high-voltage reference ground (GND) acquired by the positive busbar acquisition module be U. LINK+ The electrical signal of the bus negative terminal relative to the high-voltage reference ground GND acquired by the bus negative terminal acquisition module is U. LINK- The electrical signal of the battery pack positive terminal relative to the high-voltage reference ground GND, acquired by the battery pack positive terminal acquisition module, is U. PACK+ And the potential of the high-voltage reference ground is recorded as 0.

[0039] Based on the above electrical signal, the arithmetic module 120 can generate the following voltage value: The differential voltage between the second pole and the first pole of the busbar, i.e. the total external voltage at both ends of the busbar, is determined according to the following formula (1): V 外总压 =U LINK+ -U LINK- (1) The relative voltage between the second terminal of the battery pack and the high-voltage reference ground, i.e., the total voltage inside the battery pack, is determined according to the following formula (2): V 内总压 =U PACK+ -0=U PACK+ (2) The derivation of equation (1) is explained below. According to Kirchhoff's voltage law, the voltage between any two points in a circuit is equal to the potential difference between those two points. The voltage at the positive terminal of the bus is the potential U of the positive terminal of the bus relative to the high-voltage reference ground. LINK+ The voltage at the negative terminal of the busbar is the potential U of the negative terminal of the busbar relative to the high-voltage reference ground. LINK- Therefore, the voltage between the positive and negative terminals of the busbar is equal to the potential of the positive terminal of the busbar minus the potential of the negative terminal of the busbar, i.e., U. LINK+ -U LINK- Therefore, although the entire system can be configured with only one high-voltage reference ground, and each acquisition module acquires the single-ended electrical signal of the node under test relative to the same high-voltage reference ground, the processing module can reconstruct the differential voltage value between the two nodes under test by calculating the single-ended electrical signals of the two nodes under test, without having to configure independent reference grounds for the two nodes under test.

[0040] It should be noted that in this embodiment, the differential voltage value can be positive, zero, or negative. When the potential of the second busbar is higher than the potential of the first busbar, the differential voltage value is positive; when the potential of the second busbar is equal to the potential of the first busbar, the differential voltage value is zero; when the potential of the second busbar is lower than the potential of the first busbar, such as in reverse connection, reverse flow, or motor reverse operation, the differential voltage value is negative. In other words, the differential voltage value in this embodiment can characterize not only the magnitude of the voltage between the two measured nodes but also the direction of that voltage, thereby supporting bidirectional voltage detection.

[0041] It should also be noted that, since the nodes under test include at least the first pole of the busbar, the second pole of the busbar, the second pole of the battery pack, and the positive terminal node of the heating film, in practical applications, other nodes under test can be extended based on the above four nodes, such as the charging port voltage node, the high-voltage side node of the converter, and the air conditioning compressor branch node. For each extended node, only a corresponding acquisition module needs to be added, with its first end connected to the high-voltage reference ground and its second end connected to the extended node. This allows the acquisition of the electrical signal of the extended node relative to the high-voltage reference ground, and the processing module then generates the differential voltage value between the extended node and other nodes under test, or the relative voltage value between the extended node and the high-voltage reference ground. For example, only the corresponding positive terminal acquisition module needs to be extended, while the negative terminal reuses the common negative terminal electrical signal acquired by the common negative terminal acquisition module. In this way, the high-voltage loop acquisition system of this application embodiment has good channel expansion capability.

[0042] It should also be noted that the high-voltage circuit acquisition system 100 provided in this application embodiment can also use a time-division polling method to sequentially activate the acquisition modules corresponding to each node under test, thereby reducing the average power consumption while ensuring the sampling frequency and achieving a flexible balance between power consumption and refresh rate.

[0043] This application provides a high-voltage circuit acquisition system 100. Since the entire system uses a single high-voltage reference ground connected to the first terminal of the battery pack, and each acquisition module uses this high-voltage reference ground as a common potential reference to acquire the electrical signals of the corresponding node under test, it is not necessary to configure independent reference grounds for the positive and negative terminals of the differential acquisition. Furthermore, since the arithmetic module generates the differential voltage value between two nodes under test by subtracting their electrical signals, the voltage between any two nodes under test can be reconstructed even with only one reference ground. Therefore, this system achieves differential voltage and relative voltage acquisition for multiple nodes using a single high-voltage reference ground, avoiding the need for a dual-ground isolation architecture and dedicated differential chips, thus reducing system complexity and hardware costs while ensuring acquisition functionality.

[0044] Please see below. Figure 2 , Figure 2 This is a schematic diagram of the structure of the acquisition module 110 in a high-voltage circuit acquisition system 100 according to another embodiment of this application. Optionally, according to some feasible embodiments of this application, such as... Figure 2 As shown, each acquisition module 110 includes: a first voltage divider network 111, an acquisition unit 112, a switching unit 113, and a second voltage divider network 114; The first voltage divider network 111 includes one or more resistors connected in series. The first end of the first voltage divider network 111 is connected to the second end of the switching unit 113, and the second end of the first voltage divider network 111 is connected to the corresponding node under test. The first voltage divider network 111 is used to divide the voltage between the node under test and the switching unit 113. Switching unit 113, the first end of which is simultaneously connected to the acquisition unit 112 and the second end of the second voltage divider network 114; The second voltage divider network 114 includes one or more resistors connected in series. The first end of the second voltage divider network 114 is connected to the high voltage reference ground. The second voltage divider network is used to divide the voltage between the switching unit and the high voltage reference ground. Acquisition unit 112 is disposed between switching unit 113 and second voltage divider network 114. Acquisition unit 112 is connected to arithmetic module 120 and is used to acquire data from each node N under test. i The electrical signal between the high-voltage reference ground GND and the arithmetic module 120 is transmitted to the arithmetic module 120.

[0045] In this embodiment, the first voltage divider network 111 is set at the node to be tested N. i The resistive network between the switch unit 113 and the switch unit 113 consists of one or more resistors connected in series, and is used for the node N under test. i The voltage between the voltage divider network 111 and the switching unit 113 is divided. When the first voltage divider network 111 is composed of multiple resistors connected in series, its total resistance is the sum of the resistance values ​​of each series resistor. It should be noted that the number and resistance values ​​of the resistors in the first voltage divider network 111 can be flexibly selected according to the voltage level of the node under test and the range of the acquisition unit 112, and this application does not limit this.

[0046] The aforementioned second voltage divider network 114 is a resistive network located between the acquisition unit 112 and the high-voltage reference ground GND. It also consists of one or more resistors connected in series, used to divide the voltage between the acquisition unit 112 and the high-voltage reference ground. The total resistance of the second voltage divider network 114 is also the sum of the resistances of each series resistor. Thus, the first voltage divider network 111, the switching unit 113, the acquisition unit 112, and the second voltage divider network 114, connected in series, form a voltage divider branch connecting the node under test and the high-voltage reference ground.

[0047] Here's an explanation of voltage division. Voltage division refers to the phenomenon where a series resistor network distributes the total voltage across each resistor according to the ratio of their resistance values. According to the principle of voltage division in series circuits, the current flowing through each resistor is the same everywhere in a series circuit; therefore, the voltage across each resistor is proportional to its resistance value. In other words, the total voltage is distributed across each resistor according to its resistance value. This embodiment utilizes this principle to distribute the high voltage of the node under test relative to the high-voltage reference ground between the first and second voltage division networks according to the resistance ratio.

[0048] The aforementioned switching unit 113 is a controllable electronic switch connected in series between the first voltage divider network 111 and the acquisition unit 112, used to control the conduction and disconnection of the voltage divider branch between the node under test and the high-voltage reference ground. The first end of the switching unit 113 is simultaneously connected to the second end of the acquisition unit 112 and the second voltage divider network 114, and the second end of the switching unit 113 is connected to the first end of the first voltage divider network 111. In one embodiment, the switching unit 113 may include, for example, an optocoupler that operates in a saturated conduction or cutoff switching state. When conducting, its voltage drop across its terminals is small; when cut off, its terminals are approximately open-circuited, thereby achieving high- and low-voltage electrical isolation while controlling the on / off state of the high-voltage divider branch. It should be noted that the switching unit can also be implemented using other electronic switching devices that meet the isolation withstand voltage requirements, such as high-voltage MOSFETs and high-voltage reed switches; this application does not limit this application.

[0049] In addition to the optocoupler 1131, the aforementioned switching unit 113 may also include a low-voltage side system power supply 1133 and an optocoupler primary-side current-limiting resistor 1132, wherein the optocoupler primary-side current-limiting resistor 1132 is disposed between the low-voltage side system power supply 1133 and the optocoupler 1131 to limit the drive current.

[0050] Specifically, the switching unit 113 can be controlled by an enable signal. Taking an optocoupler as an example, the enable signal can be active low: when the enable signal is pulled low, the optocoupler is saturated and turned on, and the entire voltage divider branch consisting of the first voltage divider network 111, the switching unit 113, the acquisition unit 112, and the second voltage divider network 114 is connected, forming a complete voltage divider path between the node under test and the high-voltage reference ground, and the acquisition unit 112 enters the normal acquisition state; when the enable signal is pulled high, the optocoupler is turned off, the voltage divider branch is disconnected, and no current flows between the node under test and the high-voltage reference ground. In this way, by placing each acquisition unit 112 in the off state in the sleep or standby state, the high-voltage divider branch can be cut off, and the static leakage current of the voltage divider network can be reduced to near zero.

[0051] The aforementioned acquisition unit 112 is disposed between the second voltage divider network 114 and the switching unit 113, specifically at the connection node between the second end of the second voltage divider network 114 and the first end of the switching unit 113. It is used to acquire the voltage at the sampling point, i.e., the electrical signal obtained after voltage division between the voltage between the measured node and the high-voltage reference ground, and transmit this electrical signal to the arithmetic module 120. The acquisition unit 112 can be, for example, an analog-to-digital converter (ADC), which can be integrated into the arithmetic module 120 or a separate ADC chip. Furthermore, the acquisition unit 112 may also include a current-limiting resistor 115 to limit the current flowing into the ADC input pin, thus protecting the ADC pin.

[0052] See below. Figure 3 As an example, Figure 3 An exemplary topology of the aforementioned acquisition module 110 is shown. For example... Figure 3 As shown, the first voltage divider network 111 includes a first resistor R1 and a second resistor R2 connected in series, wherein the second end of the first resistor R1 is connected to the corresponding node N to be tested. i The first end of the first resistor R1 is connected to the second end of the second resistor R2, and the first end of the second resistor R2 is connected to the second end of the switching unit 113. In this embodiment, the switching unit 113 is preferably implemented using an optocoupler 1131, such as an ELM460A. This optocoupler 1131 can consist of a light-emitting diode D1 on the primary side and a phototransistor on the secondary side, which can be electrically isolated through optical signals. The cathode of the light-emitting diode D1 receives an external enable signal EN, and the anode of the light-emitting diode D1 is connected to the low-voltage side system power supply 1133 through the optocoupler primary-side current-limiting resistor 1132. This primary-side current-limiting resistor 1132 is connected in series between the light-emitting diode D1 and the low-voltage side system power supply 1133 to limit the forward current flowing through the light-emitting diode D1, ensuring it operates within a safe current range and that the luminous intensity is sufficient to drive the secondary side to conduct. The second voltage divider network 114 includes a third resistor R5. The first end of the third resistor R5 is connected to the high-voltage reference ground GND, and the second end of the third resistor R5 is connected to the first end of the switching unit 113, i.e., the corresponding electrode of the phototransistor. The acquisition unit 112 is disposed between the switching unit 113 and the second voltage divider network 114. Specifically, the sampling input terminal of the acquisition unit 112 is connected to the node between the first end of the switching unit 113 and the second end of the third resistor R5, for acquiring the voltage signal at this node and transmitting the electrical signal to the arithmetic module 120.

[0053] Optionally, a current-limiting resistor 115 can be set between the acquisition unit 112 and the node to limit the current flowing into the input terminal of the acquisition unit 112, so as to protect the analog-to-digital converter pin inside the acquisition unit 112 from transient current surges.

[0054] As an example, such as Figure 3 As shown, when voltage acquisition is required, the enable signal EN is set to low level. At this time, the cathode of LED D1 is at a low potential, and its anode is at a high potential because it is connected to the low-voltage side system power supply 1133 through the primary-side current-limiting resistor 1132 of the optocoupler. LED D1 conducts and emits light due to forward bias. After receiving the light signal, the phototransistor on the secondary side enters the saturated conduction state from the cutoff state. The voltage drop between its collector and emitter is extremely small and can be approximated as a short circuit, thereby putting the switching unit 113 in the conducting state. At this time, the series voltage divider branch composed of the first voltage divider network 111, the switching unit 113, and the second voltage divider network 114 is completely connected to the node under test N. i Between the high-voltage reference ground GND and the target node N, since the on-state voltage drop of the switching unit 113 is negligible, the voltage drop between the target node N and the target node GND is negligible. i The voltage relative to the high voltage reference ground GND is mainly borne by the first voltage divider network 111 and the second voltage divider network 114.

[0055] For ease of description, let the total resistance of the first voltage divider network 111 be R. 上 The total resistance of the second voltage divider network 114 is R. 下 Node N to be tested i The voltage relative to the high-voltage reference ground GND is V 节点 The voltage of the sampling point of acquisition unit 112 relative to the high-voltage reference ground GND is V. 采样 .

[0056] Since the voltage drop of the switching unit can be approximated when it is turned on, the current I flowing through the first voltage divider network 111 and the second voltage divider network 114 is: I = V 节点 / (R) 上 +R 下 ).

[0057] The voltage at the sampling point of the acquisition unit relative to the high-voltage reference ground is equal to the product of the current and the resistance of the second voltage divider network, therefore V 采样 Determine according to the following formula (3): V 采样 =I×R 下 =V 节点 ×R 下 / (R) 上 +R 下 ) ……(3) As can be seen from equation (3) above, the voltage V collected by the sampling point of the acquisition unit is...采样 The voltage V at the node to be measured 节点 The result after voltage division attenuation is that the attenuation ratio, or voltage division ratio, is R. 下 / (R) 上 +R 下 Accordingly, the arithmetic module calculates the electrical signal V transmitted from the acquisition unit. 采样 The voltage V of the node under test relative to the high-voltage reference ground can be deduced by the following formula (4). 节点 : V 节点 =V 采样 ×(R 上 +R 下 ) / R 下 (4) Accordingly, the calculation module 120 calculates the V data collected by the acquisition unit 112. 采样 ≈4.94V, and the voltage V of the node to be measured can be deduced from the above formula (4). 节点 ≈4.94V×(8MΩ+100kΩ) / 100kΩ≈4.94V×81≈400V, thus restoring the value of the node N to be tested. i The actual voltage value relative to the high-voltage reference ground GND.

[0058] When the switching unit 113 is always on, i.e. the voltage divider branch is always on, the voltage divider branch in the above example will generate a static leakage current of approximately 400V / 8.1MΩ≈49.4μA at 400V.

[0059] When a voltage acquisition is completed or the system needs to enter sleep / standby mode, the external controller pulls the enable signal high. At this time, the cathode and anode potentials of LED D1 are close, and no forward current flows through LED D1. The LED stops emitting light, and the phototransistor on the secondary side exits the saturated conduction state due to the loss of light excitation and enters the cutoff state. Its collector and emitter present extremely high impedance, which can be approximated as an open circuit. Switching unit 113 is in the off state, and the voltage divider branch between the measured node Ni and the high-voltage reference ground GND is completely cut off, preventing the formation of a current path. There is no longer any static leakage current flowing through the voltage divider network, thus significantly reducing the power consumption of the system in sleep or standby mode. Through the above process, the acquisition module 110, under the periodic on and off control of switching unit 113, realizes safe, low-power intermittent acquisition of the high-voltage measured node signal. At the same time, due to the introduction of the optocoupler, electrical isolation is achieved between the low-voltage side control circuit and the high-voltage side acquisition circuit, further improving the safety and reliability of the system.

[0060] It should be noted that by adjusting the resistance ratio of the first voltage divider network 111 and the second voltage divider network 114, the voltage division ratio can be adapted to battery systems with different voltage levels, such as 400V, 800V, or 1500V voltage platforms. This application does not limit this. When the battery system voltage level increases, the resistance value of the first voltage divider network 111 can be increased or the resistance value of the second voltage divider network 114 can be decreased accordingly, so that the voltage at the sampling point of the acquisition unit 112 is always kept within the input range of the acquisition unit 112.

[0061] In this embodiment of the application, the acquisition module, since the first voltage divider network and the second voltage divider network are connected in series between the node under test and the high-voltage reference ground, the high voltage of the node under test is shared by the two voltage divider networks. Therefore, the electrical signal acquired by the acquisition unit located between the two is the signal of the node under test N. i The low-voltage signal, after voltage attenuation through voltage division, can be acquired at high voltage without the need for high-voltage withstand devices. Furthermore, since the switching unit is connected in series between the two voltage divider networks, the voltage divider branch is cut off when the switching unit is turned off, thus reducing the static leakage current of the voltage divider network to near zero in the sleep state. Therefore, this embodiment achieves both high-voltage voltage division acquisition and the effect of cutting off the voltage divider branch and reducing static power consumption during sleep.

[0062] See below. Figure 4 , Figure 4 This is a schematic diagram of the common negative terminal acquisition module in a high-voltage circuit acquisition system 100 according to another embodiment of this application. Optionally, according to some feasible embodiments of this application, such as... Figure 4 As shown, among the N acquisition modules 110, there may be a common negative terminal acquisition module 1101. The first terminal of the common negative terminal acquisition module 1101 is connected to the high-voltage reference ground GND, and the second terminal of the common negative terminal acquisition module is connected to the first pole of the bus. Figure 4 The LINK-node connection shown; The acquisition unit in the common negative terminal acquisition module 1101 is used to acquire the common negative terminal electrical signal and transmit the common negative terminal electrical signal to the arithmetic module 120. The common negative terminal electrical signal is used to characterize the voltage of the first pole LINK of the bus relative to the high voltage reference ground GND.

[0063] In this embodiment, the common negative terminal acquisition module 1101 is one of N acquisition modules, therefore the common negative terminal acquisition module 1101 still has the following characteristics: Figure 2 and 3 The internal connections of the first voltage divider network 111, the acquisition unit 112, the switching unit 113, and the second voltage divider network 114 shown will not be described in detail here. The difference from the previous embodiment is that the node N to be tested corresponding to the common negative terminal acquisition module 1101... iSpecifically, the first pole LINK- of the busbar, which is the second pole of the common negative terminal acquisition module 1101, is connected to the first pole LINK- of the busbar. The first pole of the common negative terminal acquisition module 1101 is connected to the first pole LINK- of the busbar. The first pole of the common negative terminal acquisition module 1101 is connected to the first pole of the third resistor R5 in the second voltage divider network 114.

[0064] Here, we will explain the term "common negative terminal." "Negative terminal" refers to the first pole of the busbar, such as the negative pole of the busbar, corresponding to LINK-, which is the high-voltage node of the negative pole on the busbar side. "Common" means that the first pole of this busbar can serve as a common negative reference node for multiple acquisition branches in the system. Accordingly, the common negative terminal acquisition module 1101 is an acquisition module that uses the node under test as the first pole of the busbar, and the electrical signal acquired by its acquisition unit is called the common negative terminal electrical signal. In one example, the first pole of the busbar is the negative pole of the busbar, and the common negative terminal electrical signal corresponds to the voltage division sampling signal of the negative pole of the busbar relative to the high-voltage reference ground.

[0065] The aforementioned common negative terminal electrical signal is an electrical signal acquired by the acquisition unit in the common negative terminal acquisition module, used to characterize the voltage of the first pole of the bus relative to the high-voltage reference ground. This common negative terminal electrical signal can be, for example, a voltage signal, the amplitude of which corresponds to the potential of the first pole of the bus relative to the high-voltage reference ground.

[0066] For specific details on data collection, please refer to [link / reference]. Figure 3 The first voltage divider network 111, the switching unit 113, and the second voltage divider network 114 of the common negative terminal acquisition module 1101 are connected in series between the first pole LINK- of the bus and the high-voltage reference ground GND. When the switching unit 113 is turned on, the voltage of the first pole LINK- of the bus relative to the high-voltage reference ground GND is divided by the first voltage divider network 111 and the second voltage divider network 114. The acquisition unit 112 acquires the common negative terminal electrical signal at the sampling point between the second voltage divider network 114 and the switching unit 113.

[0067] For ease of description, let the voltage of the first pole of the busbar relative to the high-voltage reference ground be V. N The total resistance of the first voltage divider network in the common negative terminal acquisition module is R. 上 The total resistance of the second voltage divider network is R. 下 The voltage value corresponding to the common negative terminal electrical signal at the sampling point of the acquisition unit relative to the high-voltage reference ground is V. N采样 .

[0068] Based on the series voltage divider principle in the aforementioned embodiments, when the switching unit is turned on and its on-state voltage drop can be approximately ignored, V N采样 Determine according to the following formula (5): V N采样 =V N ×R下 / (R) 上 +R 下 (5) Accordingly, the arithmetic module calculates the common negative terminal electrical signal V. N采样 The voltage V of the first pole LINK of the bus relative to the high-voltage reference ground GND can be deduced by the following formula (6). N : V N =V N采样 ×(R 上 +R 下 ) / R 下 (6) It should be noted that the voltage of the first busbar terminal (LINK-) relative to the high-voltage reference ground (GND) can be positive, zero, or negative. When the potential of the first busbar terminal is higher than that of the high-voltage reference ground, the common negative terminal signal is positive; when the two potentials are equal, the common negative terminal signal is zero; when the potential of the first busbar terminal is lower than that of the high-voltage reference ground, the common negative terminal signal is negative. In other words, the common negative terminal signal can completely characterize the magnitude and direction of the voltage of the first busbar terminal relative to the high-voltage reference ground.

[0069] The common negative terminal acquisition module in this embodiment connects the second terminal to the first pole LINK- of the bus and the first terminal to the high-voltage reference ground GND. Since the common negative terminal electrical signal acquired by the acquisition unit is used to characterize the voltage of the first pole LINK- of the bus relative to the high-voltage reference ground GND, it can reflect the actual potential state of this common negative terminal reference node in real time. Furthermore, since the voltage of the first pole LINK- of the bus relative to the high-voltage reference ground GND can be positive, zero, or negative, the common negative terminal electrical signal can completely characterize its potential state under different operating conditions. Therefore, this embodiment provides a unified and reusable negative terminal reference for voltage calculation based on the potential of the first pole LINK- of the bus, simplifying the system structure while improving the completeness of the acquisition.

[0070] Please see below. Figure 5 , Figure 5 This is a schematic diagram of the structure of a bus positive terminal acquisition module 1102 in a high-voltage circuit acquisition system according to another embodiment of this application. Optionally, according to some feasible embodiments of this application, such as Figure 5 As shown, among the N acquisition modules, there is a bus positive end acquisition module 1102. The first end of the bus positive end acquisition module 1102 is connected to the high voltage reference ground GND, and the second end of the bus positive end acquisition module is connected to the second pole LINK+ of the bus. The acquisition unit of the bus positive terminal acquisition module 1102 is used to acquire the bus positive terminal electrical signal and transmit the bus positive terminal electrical signal to the arithmetic module 120. The bus positive terminal electrical signal is used to characterize the voltage of the second pole LINK+ of the bus relative to the high voltage reference ground GND. The calculation module 120 is used to perform differential calculation on the positive terminal electrical signal of the bus and the common negative terminal electrical signal to generate an external total differential voltage value. The external total differential voltage value is used to characterize the voltage between the first pole LINK- of the bus and the second pole LINK+ of the bus.

[0071] In this embodiment, the busbar positive end acquisition module 1102 is one of N acquisition modules, therefore the busbar positive end acquisition module 1102 still has the following characteristics: Figure 2 and 3 The internal connections of the first voltage divider network 111, the acquisition unit 112, the switching unit 113, and the second voltage divider network 114 shown will not be described in detail here. The difference from the previous embodiment is that the bus positive terminal acquisition module 1102 corresponds to the node N under test. i Specifically, the second pole LINK+ of the busbar, that is, the second end of the positive terminal acquisition module 1102 of the busbar, is connected to the second pole LINK+ of the busbar via the second end of the first resistor R1 in the first voltage divider network 111. The first end of the positive terminal acquisition module 1102 of the busbar is connected to the first end of the third resistor R5 in the second voltage divider network 114 via the high voltage reference ground GND.

[0072] This section describes the positive terminal electrical signal of the busbar. The positive terminal electrical signal is the signal acquired by the acquisition unit in the positive terminal acquisition module 1102, used to characterize the voltage of the second pole LINK+ of the busbar relative to the high-voltage reference ground GND. The second pole of the busbar can be, for example, the positive pole of the busbar, which is the high-voltage node on the positive pole of the busbar side. In one example, the positive terminal electrical signal corresponds to the voltage division sampling signal of the positive pole of the busbar relative to the high-voltage reference ground. It should be noted that this positive terminal electrical signal and the common negative terminal electrical signal in the aforementioned embodiment both use the same high-voltage reference ground as the potential reference; that is, both are single-ended signals to ground.

[0073] Specifically, during data acquisition, the first voltage divider network, the switching unit, and the second voltage divider network of the bus positive terminal acquisition module are connected in series between the second pole LINK+ of the bus and the high-voltage reference ground GND. When the switching unit is turned on, the voltage of the second pole LINK+ of the bus relative to the high-voltage reference ground GND is divided by the first and second voltage divider networks. The acquisition unit acquires the bus positive terminal electrical signal at the sampling point between the second voltage divider network and the switching unit.

[0074] For ease of description, let the voltage of the second pole LINK+ of the busbar relative to the high-voltage reference ground GND be V. PThe total resistance of the first voltage divider network in the busbar positive terminal acquisition module 1102 is R. 上 The total resistance of the second voltage divider network is R. 下 The sampling voltage corresponding to the electrical signal at the positive terminal of the bus is U. P According to the principle of series voltage division, U P Determine according to the following formula (7): U P =V P ×R 下 / (R) 上 +R 下 (7) Similarly, let the voltage of the first pole of the busbar relative to the high-voltage reference ground be V. N The common negative terminal acquisition module uses the same voltage division ratio as the bus positive terminal acquisition module, and the sampling voltage corresponding to the common negative terminal electrical signal is U. N It can be shown in the following formula (8): U N =V N ×R 下 / (R) 上 +R 下 (8) Based on this, the calculation module performs differential calculation between the bus positive terminal electrical signal and the common negative terminal electrical signal, that is, subtracts the common negative terminal electrical signal from the bus positive terminal electrical signal to generate the external total differential voltage value ΔU. 外总 The difference is determined according to the following formula (9): ΔU 外总 =U P -U N (9) Due to the positive terminal electrical signal U of the bus P With common negative terminal electrical signal U N Using the same high-pressure reference ground as the benchmark and the same voltage division ratio, substituting equations (7) and (8) into equation (9), we can obtain: ΔU 外总 =(V P -V N )×R 下 / (R) 上 +R 下 ).

[0075] From the above formula, it can be seen that the external total differential voltage value ΔU 外总 This is the voltage (V) between the second terminal LINK+ and the first terminal LINK- of the busbar. P -V N The result after voltage division attenuation. Where, (V P -V NThis is the voltage between the first pole LINK- and the second pole LINK+ of the busbar. Correspondingly, the calculation module can deduce the voltage V between the first pole LINK- and the second pole LINK+ of the busbar according to the following formula (10). 外总 : V 外总 =(U P -U N )×(R 上 +R 下 ) / R 下 (10) It should be noted here that the difference calculation can be performed in the sampling domain, or U can be calculated separately first. P U N Inversely, this is converted to the actual voltage V. P V N Subtracting the two results yields the same outcome, and this application does not impose any limitations on this.

[0076] It should be noted that the external total differential voltage value can be positive, zero, or negative. When the potential of the second pole of the bus is higher than that of the first pole, the external total differential voltage value is positive; when the potentials are equal, the external total differential voltage value is zero; and when the potential of the second pole of the bus is lower than that of the first pole, the external total differential voltage value is negative. In other words, the external total differential voltage value not only characterizes the magnitude of the voltage between the first and second poles of the bus, but also its direction, thus supporting bidirectional voltage detection.

[0077] In this embodiment, the bus positive terminal acquisition module acquires the electrical signal of the second bus pole (LINK+) relative to the high-voltage reference ground (GND), while the common negative terminal acquisition module acquires the electrical signal of the first bus pole (LINK-) relative to the same high-voltage reference ground (GND). Since both share the same potential reference, the calculation module subtracts the common negative terminal electrical signal from the bus positive terminal electrical signal to eliminate the common reference reference and obtain the external total differential voltage value between the first and second bus poles. Therefore, this embodiment uses only one high-voltage reference ground to achieve differential acquisition of the external total voltage, eliminating the need for separate reference grounds for the positive and negative terminals. This reduces system complexity and hardware cost while ensuring differential acquisition accuracy.

[0078] Please see below. Figure 6 , Figure 6 The acquisition module structure shown in this embodiment can specifically be a battery pack positive electrode acquisition module 1103. Optionally, according to some feasible embodiments of this application, the N acquisition modules 110 include a battery pack positive electrode acquisition module 1103, the second end of the battery pack positive electrode acquisition module 1103 is connected to the second electrode PACK+ of the battery pack, and the first end of the battery pack positive electrode acquisition module 1103 is connected to the high voltage reference ground GND; The acquisition unit of the battery pack positive terminal acquisition module 1103 is used to acquire the battery pack positive terminal electrical signal and transmit the battery pack positive terminal electrical signal to the arithmetic module 120. The battery pack positive terminal electrical signal is used to characterize the voltage of the second terminal of the battery pack relative to the high voltage reference ground. The calculation module 120 is used to calculate the potential of the positive terminal electrical signal of the battery pack and the high voltage reference ground to generate the total voltage value in the battery pack.

[0079] In this embodiment, the battery pack positive electrode acquisition module 1103 is one of N acquisition modules, therefore the battery pack positive electrode acquisition module 1103 still has the following characteristics: Figure 2 and 3 The internal connections of the first voltage divider network 111, the acquisition unit 112, the switching unit 113, and the second voltage divider network 114 shown will not be described in detail here. The difference from the previous embodiment lies in the fact that the test node N corresponding to the positive electrode acquisition module 1103 of this battery pack... i Specifically, the second terminal of the battery pack, PACK+, is the second end of the positive terminal acquisition module 1103 of the battery pack. Specifically, the second end of the first resistor R1 in the first voltage divider network 111 is connected to the second terminal of the battery pack, PACK+. The first end of the positive terminal acquisition module 1103 of the battery pack is specifically the first end of the third resistor R5 in the second voltage divider network 114, which is connected to the high voltage reference ground GND.

[0080] This section explains the total voltage within the battery pack and the electrical signal at the positive terminal of the battery pack. The total voltage within the battery pack is the voltage between the two electrodes of the battery pack, specifically the voltage between the second electrode and the first electrode. Since the high-voltage reference ground (GND) is connected to the first electrode of the battery pack, the potential of GND is the same as the potential of the first electrode. Therefore, the voltage at the second electrode relative to GND is numerically equal to the total voltage within the battery pack. The second electrode can be, for example, the positive electrode, which is the high-voltage node inside the battery pack. The electrical signal at the positive terminal of the battery pack is the signal acquired by the acquisition unit in the positive electrode acquisition module, used to characterize the voltage at the second electrode relative to GND.

[0081] Specifically, during data acquisition, the first voltage divider network, the switching unit, and the second voltage divider network of the battery pack positive terminal acquisition module 1103 are connected in series between the battery pack's second terminal PACK+ and the high-voltage reference ground GND. When the switching unit is on, the voltage of the battery pack's second terminal PACK+ relative to the high-voltage reference ground GND is divided by the first and second voltage divider networks. The acquisition unit acquires the battery pack's positive terminal electrical signal at the sampling point between the second voltage divider network and the switching unit.

[0082] For ease of description, let the voltage of the second terminal of the battery pack relative to the high-voltage reference ground be V. 内Numerically, this is equal to the total voltage within the battery pack. The total resistance of the first voltage divider network in the positive electrode acquisition module 1103 of the battery pack is R. 上 The total resistance of the second voltage divider network is R. 下 The sampling voltage corresponding to the positive terminal electrical signal of the battery pack is U. 内 According to the principle of series voltage division, U 内 Determine according to the following formula (11): U 内 =V 内 ×R 下 / (R) 上 +R 下 (11) Based on this, the calculation module 120 calculates the potential of the battery pack positive terminal electrical signal and the high-voltage reference ground GND to generate the total voltage value inside the battery pack. Since the potential of the high-voltage reference ground GND is used as the zero potential reference, that is, 0, the total voltage value inside the battery pack is the voltage V of the battery pack's second terminal PACK+ relative to the high-voltage reference ground GND. 内 The calculation module 120 can deduce the total voltage value inside the battery pack according to the following formula (12): V 内 =U 内 ×(R 上 +R 下 ) / R 下 (12) It should be noted that the total voltage value inside the battery pack in this embodiment is one of the relative voltage values ​​in the aforementioned embodiments, namely the voltage value between the second terminal PACK+ of the battery pack at the node under test and the high-voltage reference ground GND.

[0083] The battery pack positive terminal acquisition module in this embodiment connects its second terminal to the second electrode of the battery pack and its first terminal to a high-voltage reference ground. The positive terminal electrical signal of the battery pack is used to characterize the voltage of the second electrode relative to the high-voltage reference ground, which is the potential of the first electrode of the battery pack. Therefore, the calculation module calculates the voltage of the second electrode relative to the first electrode of the battery pack, i.e., the total voltage value within the battery pack, by comparing the positive terminal electrical signal with the potential of the high-voltage reference ground. Thus, this embodiment achieves single-end ground acquisition of the total voltage within the battery pack without the need for an additional reference ground, simplifying the system structure while ensuring acquisition accuracy.

[0084] Please see below. Figure 7 , Figure 7The acquisition module structure shown in this embodiment can be specifically a bus auxiliary positive terminal acquisition module 1104. Optionally, according to some feasible embodiments of this application, the N acquisition modules include the bus auxiliary positive terminal acquisition module 1104, the second end of the bus auxiliary positive terminal acquisition module 1104 is connected to the second pole LINK+ of the bus, and the first end of the bus auxiliary positive terminal acquisition module 1104 is connected to the high voltage reference ground GND; The acquisition unit in the bus auxiliary positive terminal acquisition module 1104 is used to acquire the bus auxiliary positive terminal electrical signal and transmit the bus auxiliary positive terminal electrical signal to the arithmetic module 120. The bus auxiliary positive terminal electrical signal is used to characterize the potential of the second pole LINK+ of the bus relative to the high voltage reference ground GND. The calculation module 120 is used to calculate the potential of the bus auxiliary positive terminal electrical signal and the high voltage reference ground to generate the bus auxiliary external total voltage value.

[0085] In this embodiment, the bus auxiliary positive terminal acquisition module 1104 is one of N acquisition modules, therefore the bus auxiliary positive terminal acquisition module 1104 still has the following characteristics: Figure 2 and 3 The first voltage divider network 111, the acquisition unit 112, the switching unit 113, and the second voltage divider network 114 shown here will not be described in detail here.

[0086] It should be noted that the bus auxiliary positive terminal acquisition module 1104 in this embodiment is the same as the aforementioned Figure 5The busbar positive terminal acquisition module 1102 shown differs from the busbar auxiliary positive terminal acquisition module 1104 in that the node under test corresponding to the busbar positive terminal acquisition module 1102 is also the second pole LINK+ of the busbar. Electrically, both the busbar positive terminal acquisition module 1102 and the busbar auxiliary positive terminal acquisition module 1104 are connected to the second pole LINK+ node of the busbar, and both are connected to the second pole LINK+ node of the main positive relay busbar side. They acquire the potential of the same electrical node relative to the high-voltage reference ground. Therefore, the busbar positive terminal electrical signal and the busbar auxiliary positive terminal electrical signal acquired by both are theoretically equal in value. However, it should be noted that the busbar auxiliary positive terminal acquisition module 1104 and the busbar positive terminal acquisition module 1102 are two independent acquisition channels for the same second pole LINK+ node of the busbar. The purpose of setting up two independent acquisition channels in this application is to provide redundant acquisition capabilities. The bus positive terminal acquisition module 1102 serves as the main acquisition channel. The bus positive terminal electrical signal acquired by it is mainly used to perform differential calculation with the common negative terminal electrical signal to generate the external total differential voltage value. This external total differential voltage value is one of the most critical voltage parameters in the high-voltage circuit system. It is used to characterize the actual voltage between the first pole and the second pole of the bus and is directly related to key functions such as main positive relay adhesion detection and bus voltage monitoring. The bus auxiliary positive terminal acquisition module 1104 serves as an auxiliary acquisition channel. The auxiliary external total voltage value of the bus generated by it is the single-end voltage value of the second pole of the bus relative to the high-voltage reference ground. This value does not directly participate in the calculation of the external total differential voltage value, but is used as another measurement result independent of the differential channel to perform redundancy verification and cross-validation on the acquisition data of the main channel.

[0087] Specifically, under normal system operation, the calculation module 120 can compare the auxiliary external total voltage value of the busbar with the voltage value of the second pole of the busbar to ground obtained by reverse calculation from the positive terminal electrical signal of the busbar in real time. If the deviation between the two exceeds the preset range, it indicates that there may be a fault in the main acquisition channel or the auxiliary acquisition channel, thereby triggering a system alarm or taking redundancy switching measures, effectively improving the reliability and fault tolerance of the system. In addition, under special operating conditions where the main positive relay or precharge relay sticks and causes the second pole of the busbar to become energized, the auxiliary external total voltage value of the busbar can independently provide the potential information of the second pole of the busbar from the differential acquisition channel. Combined with the total voltage value inside the battery pack and the common negative terminal electrical signal, a comprehensive judgment is made to help the system more accurately locate the fault type. For example, when the main positive relay is stuck, the potential of the second pole of the bus should be close to the potential of the second pole of the battery pack. By comparing the total auxiliary external voltage value of the bus with the total internal voltage value of the battery pack, the accuracy of the sticking judgment can be confirmed. When the main positive relay is normally disconnected, the second pole of the bus should gradually discharge through the load discharge circuit, and the total auxiliary external voltage value of the bus should gradually decrease over time. If this value remains high, it further confirms the possibility that the main positive relay or precharge relay is stuck. Therefore, although the bus auxiliary positive terminal acquisition module 1104 and the bus positive terminal acquisition module 1102 are both electrically connected to the second pole LINK+ node of the bus, and both acquire the potential information of the same node, the total auxiliary external voltage value of the bus, as a redundant auxiliary parameter, plays an irreplaceable role in scenarios such as system fault diagnosis, acquisition channel self-test, and key parameter mutual verification. It can effectively avoid the measurement blind zone or misjudgment risk caused by the failure of a single acquisition channel, and improve the overall reliability and safety of the high-voltage circuit acquisition system.

[0088] Specifically, during data acquisition, the first voltage divider network, the switching unit, and the second voltage divider network of the bus auxiliary positive terminal acquisition module 1104 are connected in series between the second pole LINK+ of the bus and the high-voltage reference ground GND. When the switching unit is turned on, the voltage of the second pole LINK+ of the bus relative to the high-voltage reference ground GND is divided by the first and second voltage divider networks. The acquisition unit acquires the bus auxiliary positive terminal electrical signal at the sampling point between the second voltage divider network and the switching unit.

[0089] For ease of description, let the voltage of the second pole of the busbar relative to the high-voltage reference ground be V. LINK+ The total resistance of the first voltage divider network in the bus auxiliary positive terminal acquisition module is R. 上 The total resistance of the second voltage divider network is R. 下 The sampling voltage corresponding to the auxiliary positive terminal electrical signal of the busbar is U. aux According to the principle of series voltage division, U aux Determine according to the following formula (13): U aux =V LINK+×R 下 / (R) 上 +R 下 (13) Based on this, the calculation module 120 calculates the potential of the bus auxiliary positive terminal electrical signal and the high-voltage reference ground GND to generate the total external voltage value of the bus auxiliary. Since the potential of the high-voltage reference ground GND is used as the zero potential reference (i.e., 0), the total external voltage value of the bus auxiliary is the voltage V of the second pole LINK+ of the bus relative to the high-voltage reference ground GND. LINK+ The calculation module 120 can deduce the total auxiliary external voltage value of the bus according to the following formula (14): V LINK+ =U aux ×(R 上 +R 下 ) / R 下 (14) It should be noted that the bus auxiliary external total voltage value in this embodiment is one of the relative voltage values ​​in the aforementioned embodiments, namely, the voltage value between the second pole LINK+ of the bus under test node and the high-voltage reference ground GND. The bus auxiliary external total voltage value can be positive, zero, or negative. When the potential of the second pole LINK+ of the bus is lower than the potential of the high-voltage reference ground GND, the bus auxiliary external total voltage value is negative, thus fully characterizing the potential state of the second pole LINK+ of the bus relative to the high-voltage reference ground.

[0090] The bus auxiliary positive terminal acquisition module in this embodiment connects its second terminal to the second pole of the bus and its first terminal to the high-voltage reference ground. Since the bus auxiliary positive terminal electrical signal is used to characterize the potential of the second pole of the bus relative to the high-voltage reference ground, and the high-voltage reference ground has a zero potential reference, the calculation module can obtain the voltage of the second pole of the bus relative to the high-voltage reference ground by calculating the bus auxiliary positive terminal electrical signal and the high-voltage reference ground potential. This is the total external voltage value of the bus auxiliary terminal. Therefore, this embodiment provides a single-ended auxiliary measurement result to ground for the potential of the second pole of the bus, which can be used for redundancy verification and comparison of the bus voltage, improving system reliability while simplifying the acquisition structure.

[0091] Please see below. Figure 8 , Figure 8 This is a schematic diagram of the structure of a high-voltage circuit acquisition system 100 provided in another embodiment of this application. Optionally, according to some feasible embodiments of this application, such as... Figure 8 As shown, among the N acquisition modules, there is a heating film positive terminal acquisition module 1105. The second terminal of the heating film positive terminal acquisition module 1105 is connected to the heating relay 400, and the first terminal of the heating film positive terminal acquisition module 1105 is connected to the high voltage reference ground GND. The heating relay 400 is located between the first pole LINK- and the second pole LINK+ of the busbar. The acquisition unit in the heating film positive terminal acquisition module 1105 is used to acquire the heating film positive terminal electrical signal and transmit the heating film positive terminal electrical signal to the arithmetic module 120. The heating film positive terminal electrical signal is used to characterize the voltage of the heating relay 400 relative to the high voltage reference ground GND. The arithmetic module 120 is used to perform differential calculations on the electrical signal at the positive end of the heating film and the electrical signal at the common negative end to generate differential voltage values ​​at both ends of the heating film.

[0092] In this embodiment, the heating film positive end acquisition module 1105 is one of N acquisition modules, therefore the heating film positive end acquisition module 1105 still has the following characteristics: Figure 2 and 3 The internal connections of the first voltage divider network 111, the acquisition unit 112, the switching unit 113, and the second voltage divider network 114 shown will not be described in detail here. The difference from the previous embodiment lies in the fact that the node N to be measured corresponding to the positive end acquisition module 1105 of the heating film... i Specifically, the positive terminal of the heating film of the heating relay 400, i.e., the node between the heating relay 400 and the heating film, is the second terminal of the heating film positive terminal acquisition module 1105. Specifically, the second terminal of the first resistor R1 in the first voltage divider network 111 is connected to the positive terminal of the heating film of the heating relay 400. The first terminal of the heating film positive terminal acquisition module 1105 is specifically the first terminal of the third resistor R5 in the second voltage divider network 114, which is connected to the high voltage reference ground GND.

[0093] This section describes the heating relay 400 and the heating film. The heating relay 400 is a switching device in the heating circuit, located between the first terminal LINK- and the second terminal LINK+ of the busbar, used to control the on / off power supply to the heating film. The heating film can be, for example, a positive temperature coefficient (PTC) heating film, which is the heating element for low-temperature heating of the battery pack, increasing the battery pack temperature after being powered on. In one example, the connection of the heating branch is as follows: the second terminal LINK+ of the busbar is connected to the positive terminal of the heating film via the heating relay 400, and the lower end of the heating film is connected to the heating film resistor 500 and finally connected to the first terminal LINK- of the busbar.

[0094] The aforementioned electrical signal at the positive end of the heating film is the electrical signal acquired by the acquisition unit in the heating film positive end acquisition module 1105, which is used to characterize the voltage of the positive end of the heating film relative to the high voltage reference ground GND. In one example, the electrical signal at the positive end of the heating film corresponds to the voltage divider sampling signal of the positive end of the heating film relative to the high voltage reference ground GND.

[0095] Specifically, during data acquisition, the first voltage divider network, the switching unit, and the second voltage divider network of the heating film positive terminal acquisition module 1105 are connected in series between the heating film positive terminal and the high-voltage reference ground GND. When the switching unit is turned on, the voltage of the heating film positive terminal relative to the high-voltage reference ground GND is divided by the first voltage divider network and the second voltage divider network. The acquisition unit acquires the electrical signal of the heating film positive terminal at the sampling point between the second voltage divider network and the switching unit.

[0096] For ease of description, let the voltage of the positive terminal of the heating film relative to the high-voltage reference ground be V. PTC+ The total resistance of the first voltage divider network in the positive terminal acquisition module 1105 of the heating film is R. 上 The total resistance of the second voltage divider network is R. 下 The sampling voltage corresponding to the electrical signal at the positive end of the heating film is U. PTC According to the principle of series voltage division, U PTC Determine according to the following formula (15): U PTC =V PTC +×R 下 / (R) 上 +R 下 (15) Since the common negative terminal acquisition module uses the same voltage division ratio as the heating film positive terminal acquisition module, the voltage of the first pole of the bus relative to the high voltage reference ground is V. N The sampling voltage corresponding to the common negative terminal electrical signal is U. N ,but: U N =V N ×R 下 / (R) 上 +R 下 (16) Based on this, the calculation module 120 performs differential calculation between the electrical signal at the positive end of the heating film and the electrical signal at the common negative end, that is, subtracts the electrical signal at the common negative end from the electrical signal at the positive end of the heating film to generate the differential voltage value ΔU across the heating film. PTC The difference is determined according to the following formula (17): ΔU PTC =U PTC -U N (17) Substituting equations (15) and (16) into equation (17), we can obtain: ΔU PTC =V PTC ×R 下 / (R) 上 +R 下 ) From the above formula, it can be seen that the differential voltage value ΔU across the heating film is... PTC That is, the voltage V between the two ends of the heating film.PTC The result after voltage division and attenuation. Accordingly, the arithmetic module 120 can deduce the voltage V between the two ends of the heating film according to the following formula (18). PTC : V PTC =ΔU PTC ×(R 上 +R 下 ) / R 下 =(U PTC -U N )×(R 上 +R 下 ) / R 下 (18) It should be noted that the differential voltage across the heating film can be positive, zero, or negative. When the potential at the positive terminal of the heating film is higher than that at the lower terminal, the differential voltage across the heating film is positive; when the potentials are equal, the differential voltage across the heating film is zero; when the potential at the positive terminal is lower than that at the lower terminal, the differential voltage across the heating film is negative.

[0097] The heating film positive terminal acquisition module and its differential calculation in this embodiment utilize the fact that the lower end of the heating film and the common negative terminal sampling point are at the same potential node. Since the heating film positive terminal acquisition module acquires the electrical signal of the heating film positive terminal relative to the high-voltage reference ground, the calculation module subtracts the common negative terminal electrical signal from the heating film positive terminal electrical signal, thus eliminating the common reference point and obtaining the voltage between the heating film positive terminal and the lower end, i.e., the differential voltage value across the heating film. Therefore, this embodiment can complete the differential acquisition of the voltage across the heating film using only the common negative terminal electrical signal, eliminating the need for a separate negative terminal acquisition channel for the heating film. This reduces system complexity and cost while ensuring acquisition accuracy.

[0098] Please see below. Figure 9 , Figure 9 This is a schematic diagram of the structure of a high-voltage circuit acquisition system 100 provided in another embodiment of this application. Optionally, according to some feasible embodiments of this application, such as... Figure 9 As shown, the N acquisition modules include a common negative terminal acquisition module 1101 and a bus positive terminal acquisition module 1102; the system also includes a bias module 600 and a reference voltage source 700. The bias module 600 is located between the reference voltage source 700 and the high voltage reference ground GND. The bias module 600 includes a bias node 601. The first ends of the common negative terminal acquisition module 1101 and the bus positive terminal acquisition module 1102 are both connected to the high voltage reference ground GND through the bias node 601. The bias module 600 is used to provide common-mode DC bias voltage to the common negative terminal acquisition module 1101 and the bus positive terminal acquisition module 1102, respectively.

[0099] In this embodiment, the aforementioned reference voltage source 700 is a reference voltage source located on the high-voltage side, used to output a stable DC reference voltage. The DC reference voltage output by the reference voltage source 700 can be, for example, 2.5V, or other voltage levels such as 1.25V, 3V, etc., and this application does not limit this. In one example, the reference voltage source 700 can be implemented using a low-dropout linear regulator, a voltage reference chip, or a Zener diode, etc., to output a relatively stable DC voltage.

[0100] The aforementioned bias module 600 is a circuit module located between the reference voltage source 700 and the high-voltage reference ground GND, and includes a bias node 601. The bias module 600 is used to form a DC potential at the bias node 601 based on the DC reference voltage output by the reference voltage source 700, and provides this DC potential as a common-mode DC bias voltage to the common negative terminal acquisition module 1101 and the bus positive terminal acquisition module 1102 respectively.

[0101] This section explains the common-mode DC bias voltage and bias node. The common-mode DC bias voltage refers to the DC voltage components of the same magnitude that are simultaneously superimposed on the sampling reference points of the common negative terminal acquisition module 1101 and the bus positive terminal acquisition module 1102. The bias node 601 is the connection node in the bias module 600 used to provide this common-mode DC bias voltage to the two acquisition modules. In this embodiment, the first terminals of the common negative terminal acquisition module 1101 and the bus positive terminal acquisition module 1102 are no longer directly connected to the high-voltage reference ground, but are both connected to the high-voltage reference ground GND through the bias node 601. That is, the first terminals of both acquisition modules are connected to the bias node 601, so that the DC potential at the bias node 601 can act on the two acquisition modules simultaneously in a common-mode form.

[0102] In this embodiment, the core function of the bias module 600 is to inject a stable common-mode DC bias voltage into the high-voltage acquisition circuit, thereby raising the potential of the node under test, which may be negative relative to the high-voltage reference ground, to the range that can be acquired by the single-power-supply acquisition circuit. This allows for the complete acquisition of the negative voltage signal without the need for additional high-voltage negative power supply or bipolar power supply.

[0103] To facilitate understanding the working mechanism of the bias module, it is first necessary to clarify the functional positioning of the common negative terminal acquisition module 1101 and the bus positive terminal acquisition module 1102 in the aforementioned high-voltage circuit acquisition system. The bus positive terminal acquisition module 1102 is used to acquire the single-end voltage to ground of the second pole LINK+ of the bus relative to the high-voltage reference ground. The acquired bus positive terminal electrical signal U... PIt is the positive input for calculating the external differential voltage value; the common negative terminal acquisition module 1101 is used to acquire the single-ended ground voltage of the first pole LINK of the bus relative to the high-voltage reference ground, and the common negative terminal electrical signal U acquired by it. N As the common negative terminal reference for multiple differential channels in the entire system, it is the negative terminal input for calculating the total external differential voltage value. The arithmetic module 120 uses U... P with U N Subtraction yields the total external differential voltage value ΔU 外总 =U P -U N This value, after being converted by the voltage divider ratio, is the actual voltage between the first and second poles of the busbar. Therefore, the busbar positive terminal acquisition module 1102 and the common negative terminal acquisition module 1101 together constitute the core measurement link for external total voltage differential acquisition. The quality of their sampling signals directly determines the accuracy and reliability of the external total differential voltage value.

[0104] In the aforementioned dual-end acquisition architecture, the bias module 600 injects a common-mode DC bias voltage into the sampling branches of both the bus positive-end acquisition module 1102 and the common negative-end acquisition module 1101 simultaneously through the bias node 601, thereby raising the overall operating point of the sampling points of the two acquisition modules. Specifically, without this common-mode DC bias voltage, when the potential of the second pole LINK+ of the bus is lower than the potential of the high-voltage reference ground GND, the potential of the sampling point of the bus positive-end acquisition module 1102 will also become negative. However, conventional single-supply acquisition circuits typically require the input voltage to be within the positive range from ground potential to the supply voltage, and cannot accept negative voltage input. Therefore, the negative voltage signal will be outside the acquisition range and cannot be acquired, resulting in a detection blind zone in the system under negative voltage fault conditions such as bus reverse connection, motor reverse drive, or energy backflow. In this embodiment, since the bias module 600 establishes a stable DC potential at the bias node 601 that is higher than the high voltage reference ground GND, and injects this potential into the sampling branch of the bus positive terminal acquisition module 1102 and the sampling branch of the common negative terminal acquisition module 1101 in common mode, the sampling point voltages of the two acquisition modules are superimposed with a fixed DC bias component on the original voltage component of the node under test.

[0105] The actual function of the common-mode DC bias voltage described above will be explained below in conjunction with the operating conditions. When the potential of the second pole of the bus is equal to that of the first pole of the bus, the sampling point voltage of the bus positive terminal acquisition module 1102 and the sampling point voltage of the common negative terminal acquisition module 1101 are both near the common-mode DC bias voltage. The corresponding conversion result after subtracting the two is approximately 0V. When the potential of the second pole of the bus is higher than that of the first pole of the bus, the sampling point voltage of the bus positive terminal acquisition module 1102 is higher than the common-mode DC bias voltage, and the sampling point voltage of the common negative terminal acquisition module 1101 is lower than or equal to the common-mode DC bias voltage. The corresponding conversion result after subtracting the two is positive. When the potential of the second pole of the bus is lower than that of the first pole of the bus, the sampling point voltage of the bus positive terminal acquisition module 1102 is lower than the common-mode DC bias voltage. However, due to the rise effect of the common-mode DC bias voltage, the sampling point voltage is still kept above ground potential and within the positive acquisition area. This allows the negative voltage signal that could not originally be acquired by the single power supply acquisition circuit to be completely acquired, and the corresponding conversion result is negative. In the subsequent differential operation, the operation module 120 calculates the external total differential voltage value ΔU. 外总 =U P -U N Bias voltage V bias The bias voltage is completely canceled out during the differential operation, and will not affect the differential measurement results. Therefore, the bias module 600 generates a common-mode DC bias voltage through an equivalent symmetrical resistor voltage divider structure. This not only shifts the bipolar input signal as a whole into the positive acquisition area, enabling the single-supply acquisition circuit to cover the negative voltage detection requirements, but also uses the common-mode cancellation characteristic to ensure that the accuracy of the differential measurement is not affected by the bias voltage. Thus, it solves the technical problem of requiring an additional high-voltage negative power supply or bipolar power supply for negative voltage acquisition at a very low hardware cost.

[0106] It should be noted that the value of the common-mode DC bias voltage can be adjusted as needed. For example, when it is necessary to increase the proportion of the negative vector range, the common-mode DC bias voltage can be increased accordingly; when the positive vector range requirement is greater than the negative vector range, the common-mode DC bias voltage can be decreased accordingly. Correspondingly, the voltage level of the reference voltage source and the resistance ratio of each resistor in the bias module can be set according to the actual range requirements, and this application does not impose any restrictions on this.

[0107] In this embodiment, the bias module and the reference voltage source are positioned between the reference voltage source and the high-voltage reference ground. Since the first terminals of both the common negative terminal acquisition module and the bus positive terminal acquisition module are connected to the high-voltage reference ground via a bias node, the DC potential formed at the bias node can simultaneously raise the sampling operating point of both acquisition modules in common-mode form, causing the bipolar input signal to shift entirely into the positive acquisition region. Furthermore, because this common-mode bias is superimposed on both the positive and negative terminals, the common-mode components cancel each other out during differential calculations, thus the bias does not affect the differential measurement results. Therefore, this embodiment achieves bidirectional voltage acquisition under single-power supply without requiring an additional negative power supply, maintaining acquisition accuracy while expanding negative voltage detection capabilities.

[0108] See below. Figure 9 Optionally, according to some feasible embodiments of this application, the bias module 600 includes at least h1 first bias resistors 602 and h2 second bias resistors 603, wherein the total resistance of h1 first bias resistors 602 is equal to the total resistance of h2 second bias resistors 603, and h1 and h2 are both positive integers; h1 first bias resistors 602 are connected in series between the reference voltage source 700 and the bias node 601. The second end of h1 first bias resistors 602 is connected to the reference voltage source 700, and the first end of h1 first bias resistors 602 is connected to the bias node 601. h2 second bias resistors 603 are connected in series between bias node 601 and high voltage reference ground GND. The second end of h2 second bias resistors 603 is connected to bias node 601, and the first end of h2 second bias resistors 603 is connected to high voltage reference ground GND.

[0109] In this embodiment, the aforementioned first bias resistor 602 is a bias resistor disposed between the reference voltage source 700 and the bias node 601. There are h1 such first bias resistors 602, which are connected in series to form a series branch. The first end of this series branch is connected to the reference voltage source 700, and the last end is connected to the bias node 601. The total resistance of the h1 first bias resistors 602 is the sum of the resistance values ​​of each first bias resistor in this series branch. Here, h1 is a positive integer, meaning h1 can take any positive integer such as 1, 2, or 3.

[0110] The aforementioned second bias resistor 603 is a bias resistor disposed between the bias node 601 and the high-voltage reference ground GND. There are h² such resistors, and these h² second bias resistors 603 are connected in series, forming a series branch. In this series branch, the first end is connected to the bias node 601, and the last end is connected to the high-voltage reference ground GND. The total resistance of the aforementioned h² second bias resistors 603 is the sum of the resistance values ​​of each second bias resistor 603 in this series branch. Here, h² is also a positive integer.

[0111] It should be noted that in this embodiment, the total resistance of the h1 first bias resistors 602 is equal to the total resistance of the h2 second bias resistors 603, thereby making the bias module 600 form an equal and symmetrical voltage divider structure on the upper and lower sides of the bias node 601.

[0112] For ease of description, let the total resistance of the h1 first bias resistors 602 be R. 上偏 The total resistance of the two second bias resistors 603 is R. 下偏 The DC reference voltage output by the reference voltage source 700 is V. ref The voltage at bias node 601, i.e., the common-mode DC bias voltage, is V. bias .

[0113] It should be noted that the h1 first bias resistors 602 and h2 second bias resistors 603 are connected in series. This allows for flexible acquisition of the required total resistance value through combinations of multiple standard resistors. Furthermore, in high-voltage applications, connecting multiple resistors in series can distribute the voltage stress applied to each resistor, improving the voltage withstand reliability of the bias module. The specific resistance values ​​and quantities of each first and second bias resistor can be determined according to actual needs, and this application does not impose any limitations on this.

[0114] It should also be noted that, since the resistors on the upper and lower sides of the bias module in this embodiment are of equal and symmetrical structure, the deviation of the output voltage of the reference voltage source will act on the first bias resistor branch and the second bias resistor branch in the same proportion, thereby superimposing on the sampling signals on both sides of the bias node in the form of common-mode components. This makes the reference source deviation superimposed in the form of common-mode components and canceled out by subtraction in the differential operation, so that the differential measurement result is not affected by the accuracy of the reference voltage source.

[0115] In this embodiment of the bias module, since the total resistance of the h1 first bias resistors is equal to the total resistance of the h2 second bias resistors, forming an equivalent symmetrical voltage divider structure, the voltage of the reference voltage source is evenly divided at the bias node, and the bias node voltage is always half of the output voltage of the reference voltage source. Furthermore, because this symmetrical structure causes the deviation of the reference voltage source to act simultaneously and equally on the upper and lower branches, superimposed as common-mode components and subtracted to cancel each other out during differential operations, the common-mode DC bias voltage is not affected by the accuracy of the reference voltage source. Therefore, this embodiment achieves a stable common-mode DC bias that is insensitive to reference source errors using an equivalent symmetrical voltage divider structure, ensuring bidirectional acquisition capability while allowing the use of low-cost, common reference devices.

[0116] It is understood that the above are all examples and do not serve as a substantial limitation on the high-voltage circuit acquisition system 100 protected by this application.

[0117] Based on the high-voltage circuit acquisition system 100 provided in the foregoing embodiments, correspondingly, this application also provides a detection method for the high-voltage circuit system 1000, which is described below in conjunction with... Figure 10 and Figure 11 The high-voltage circuit system 1000 to which the detection method provided in the embodiments of this application is applicable will be described. Figure 10 The complete structural diagram shown illustrates both the high-voltage circuit acquisition system and the switching device topology of the high-voltage circuit. Optionally, according to some feasible embodiments of this application, this application provides a detection method for a high-voltage circuit system.

[0118] Among them, such as Figure 10 As shown, the high-voltage circuit system 1000 includes a high-voltage circuit acquisition system 100, a main positive relay 200, a main negative relay 800, a pre-charge branch 300, and a heating relay 400. The high-voltage circuit acquisition system 100 includes N acquisition modules 110 and a processing module 120. The N acquisition modules 110 may include a common negative terminal acquisition module 1101, a bus positive terminal acquisition module 1102, a battery pack positive terminal acquisition module 1103, a bus auxiliary positive terminal acquisition module 1104, and a heating film positive terminal acquisition module 1105. A heating film resistor 500 is also provided between the heating relay 400 and the first pole LINK- of the bus. The first terminal of each acquisition module 110 is connected to the high-voltage reference ground GND, and the second terminal of each acquisition module 110 is connected to the corresponding node under test N. i The high-voltage reference ground GND is connected to the first terminal PACK- of the battery pack. The node under test includes at least the first terminal LINK- of the bus, the second terminal LINK+ of the bus, the second terminal PACK+ of the battery pack, and the positive terminal node of the heating film, where N is a positive integer. The positive terminal node of the heating film is the high-voltage node between the heating relay and the heating film. The heating relay is located between the first terminal and the second terminal of the bus.

[0119] In this embodiment, the aforementioned main positive relay 200 is a main circuit positive switch located between the second terminal PACK+ of the battery pack and the second terminal LINK+ of the bus, used to control the connection and disconnection between the second terminal PACK+ of the battery pack and the second terminal LINK+ of the bus. It is closed during normal operation and open when power is off. The aforementioned main negative relay 800 is a main circuit negative switch located between the first terminal PACK- of the battery pack and the first terminal LINK- of the bus, used to control the connection and disconnection between the first terminal PACK- of the battery pack and the first terminal LINK- of the bus, and serves as a safety switch for the negative terminal of the main circuit.

[0120] The aforementioned pre-charge branch 300 is connected in parallel with the main positive relay 200 between the second terminal LINK+ of the bus and the second terminal PACK+ of the battery pack. The pre-charge branch 300 includes a pre-charge relay 301 and a pre-charge resistor 302 connected in series. The pre-charge relay 301 is the switch of the pre-charge circuit, which closes before the main positive relay 200 at the initial stage of power-on. The pre-charge resistor 302 is a current-limiting resistor connected in series in the pre-charge circuit, used to limit the inrush current charging the bus capacitor at the moment of power-on, thereby protecting the relay contacts and the bus capacitor.

[0121] The aforementioned heating relay 400 is a heating circuit switch located between the first pole LINK- and the second pole LINK+ of the busbar, used to control the on / off state of the power supply to the heating film, for example, closing when the battery is heated at low temperatures and opening at normal temperatures. The heating film can be, for example, a positive temperature coefficient heating film.

[0122] Based on the aforementioned high-voltage circuit system 1000, such as Figure 11 As shown, the detection method provided in this application includes the following steps: S100, acquire electrical signals of N nodes under test relative to the high-voltage reference ground; S200, based on the electrical signal of each node under test relative to the high voltage reference ground, generates at least one of the differential voltage value between each node under test and the relative voltage value between each node under test and the high voltage reference ground; S300 determines the electrical state of the high-voltage circuit based on at least one of the differential voltage value and the relative voltage value.

[0123] The specific implementation methods of steps 100 to 300 above will be described in detail below.

[0124] In S300, the aforementioned electrical state refers to the electrical operating state of the high-voltage circuit, which may include, for example, the on / off state of relays in the high-voltage circuit, the voltage state on the busbar and battery pack, etc. Since the differential voltage value and the relative voltage value reflect the voltage relationship between each node under test in the high-voltage circuit, and these voltage relationships are determined by the on / off state of switching devices such as the main positive relay, the main negative relay, the precharge relay, and the heating relay, the electrical state of the high-voltage circuit can be determined based on at least one of the differential voltage value and the relative voltage value.

[0125] It should be noted that, in the embodiments of this application, the electrical state can be determined based on differential voltage values, relative voltage values, or a combination of both; this application does not limit this. Furthermore, the type of electrical state is not limited to the examples above and can be determined according to actual testing requirements.

[0126] The detection method of this application acquires electrical signals from each node under test relative to the same high-voltage reference ground through a data acquisition module, and generates differential and relative voltage values ​​based on these signals. These voltage values ​​correspond to the on / off states of each relay in the high-voltage circuit. Therefore, it is not necessary to directly detect the physical location of the relay contacts; the electrical state of the high-voltage circuit can be determined based on the differential and relative voltage values. Thus, this embodiment indirectly reflects the electrical state of the circuit using voltage acquisition results, achieving non-contact state detection of the high-voltage circuit and improving the reliability and convenience of the detection.

[0127] The following describes in detail the specific implementation of determining the electrical state of the high-voltage circuit in this application embodiment, based on the circuit structure of the high-voltage circuit system 1000 provided in the foregoing embodiments. In this application embodiment, the electrical state may include one or more of the following: the bus positive circuit relay sticking state, the bus negative circuit relay sticking state, and the heating branch relay sticking state.

[0128] Here, we will first explain adhesion. Adhesion refers to a fault phenomenon where the moving and stationary contacts of a relay remain in a conductive or semi-conductive state even after a disconnection command is issued from the control terminal, due to reasons such as welding, erosion, or mechanical jamming. For example, if the main positive relay is adhered, even if the system has issued a disconnection command, the second terminal of the battery pack and the second terminal of the bus may still remain conductive, and the bus will be continuously charged by the battery pack and unable to discharge normally. The embodiments of this application can perform online diagnosis of the above three types of relay adhesion states based on at least one of the differential voltage value and relative voltage value generated in the aforementioned step S200, without needing to directly detect the physical position of the relay contacts. These will be described in detail below.

[0129] Optionally, according to some feasible embodiments of this application, the electrical state includes the relay sticking state of the bus positive circuit. Determining the electrical state of the high-voltage circuit includes the following steps: When the main positive relay, precharge relay and main negative relay are all disconnected, the reference electrical signal of the common negative terminal is determined based on the electrical signal of the first pole of the bus relative to the high voltage reference ground. The external total differential voltage value is generated based on the electrical signal of the second pole of the bus relative to the high voltage reference ground and the common negative terminal reference electrical signal. The total voltage within the battery pack is determined based on the electrical signal of the second terminal of the battery pack relative to the high-voltage reference ground. If the difference between the external total differential voltage and the total voltage inside the battery pack is greater than or equal to a preset difference threshold, it is determined that at least one of the main positive relay and the precharge relay is stuck together.

[0130] Here, we will first explain the relevant terms involved in the testing.

[0131] The busbar positive circuit refers to the power supply path from the positive terminal of the battery pack to the positive terminal of the busbar, consisting of the second terminal PACK+ of the battery pack, the main positive relay 200, the precharge branch 300, and the second terminal LINK+ of the busbar. Specifically, the main positive relay 200 and the precharge branch 300 are connected in parallel between the second terminal LINK+ of the busbar and the second terminal PACK+ of the battery pack. The precharge branch 300 includes a precharge relay 301 and a precharge resistor 302 connected in series.

[0132] The preset difference threshold is a voltage judgment threshold used to measure the closeness between the external total differential voltage value and the internal total voltage value of the battery pack.

[0133] Specifically, the detection process in this embodiment is performed when the main positive relay 200, precharge relay 301, and main negative relay 800 are all in the command-disconnected state. At this time, the connection between the second terminal PACK+ of the battery pack and the second terminal LINK+ of the bus, and the connection between the first terminal PACK- of the battery pack and the first terminal LINK- of the bus, are normally disconnected, and there is no direct power supply path between the bus side and the battery pack.

[0134] The above-mentioned determination logic will be explained below in conjunction with the circuit structure of the aforementioned high-voltage circuit system 1000.

[0135] When both the main positive relay 200 and the precharge relay 301 are normally disconnected, there is no conductive path between the battery pack's second terminal PACK+ and the bus's second terminal LINK+. The voltage between the bus's second terminal LINK+ and the bus's first terminal LINK- gradually decreases and approaches 0 through the load discharge circuit. Therefore, the external total differential voltage value is lower than the total voltage value inside the battery pack, and the difference between the two is negative. However, when the main positive relay 200 or the precharge relay 301 becomes stuck, the battery pack's second terminal PACK+ will conduct through the stuck contacts to the bus's second terminal LINK+. The bus's second terminal LINK+ is charged to a potential close to that of the battery pack's second terminal PACK+. At this time, the external total differential voltage value will rise and approach the total voltage value inside the battery pack, and the difference between the two will approach 0. Accordingly, in this embodiment, if the difference between the external total differential voltage value and the total voltage value inside the battery pack is greater than or equal to a preset difference threshold, it can be determined that at least one of the main positive relay and the precharge relay has become stuck.

[0136] The aforementioned preset difference threshold can be understood as a voltage criterion used to distinguish between the bus being normally discharged and the bus being charged by the battery pack. The aforementioned preset difference threshold can be set to a negative value close to 0, for example, it can be set in the range of approximately -50V to 0V. The specific value can be determined comprehensively based on factors such as the bus capacitance, the load discharge time constant, and the allowable sampling error. This application does not limit this.

[0137] In this embodiment of the application, the bus auxiliary external total voltage value can also be used to perform redundancy verification on the above determination result. Its specific function and judgment logic are as follows.

[0138] The bus auxiliary positive terminal electrical signal acquired by the bus auxiliary positive terminal acquisition module 1104 is used to generate the bus auxiliary external total voltage value. This value represents the single-end ground voltage of the second pole LINK+ of the bus relative to the high voltage reference ground GND. It forms two independent acquisition channels with the bus positive terminal acquisition module 1102.

[0139] When this application embodiment determines that at least one of the main positive relay and the precharge relay is stuck based on the difference between the external total differential voltage value and the total voltage value inside the battery pack being greater than or equal to a preset difference threshold, the external total voltage value of the bus auxiliary can be further compared with the total voltage value inside the battery pack: if the external total voltage value of the bus auxiliary is also close to the total voltage value inside the battery pack, then the independent single-ended acquisition channel confirms that the second pole of the bus LINK+ has been charged to a potential close to the second pole of the battery pack PACK+, and the sticking determination is established; if the external total voltage value of the bus auxiliary is significantly lower than the total voltage value inside the battery pack, but the external total differential voltage value is close to the total voltage value inside the battery pack, then it indicates that the voltage corresponding to the common negative terminal reference electrical signal may be abnormal, for example, the first pole of the bus LINK- is at a negative potential. In this case, other detection results should be combined for comprehensive judgment to reduce the risk of misjudgment caused by errors or faults in a single acquisition channel.

[0140] Optionally, according to some feasible embodiments of this application, the electrical state also includes the state of relay sticking in the negative busbar circuit. Determining the electrical state of the high-voltage circuit includes the following steps: When the main positive relay is open, the precharge relay is closed, and the main negative relay is open, the reference electrical signal of the common negative terminal is determined based on the electrical signal of the first pole of the bus relative to the high voltage reference ground. A differential voltage value is generated based on the electrical signal of the second terminal of the battery pack relative to the high voltage reference ground and the reference electrical signal of the common negative terminal. If the differential voltage value is greater than the first preset voltage threshold, it is determined that the main negative relay has stuck.

[0141] Here, we will first explain the relevant terms involved in the testing.

[0142] The busbar negative circuit refers to the power supply path from the battery pack negative terminal to the busbar negative terminal, formed by the first terminal PACK- of the battery pack, the main negative relay 800, and the first terminal LINK- of the busbar. The main negative relay 800 is connected between the first terminal PACK- of the battery pack and the first terminal LINK- of the busbar, and serves as a safety switch on the negative side of the main circuit. The differential voltage value, in this embodiment, refers to the differential voltage between the voltage of the second terminal PACK+ of the battery pack relative to the high-voltage reference ground GND and the voltage of the first terminal LINK- of the busbar relative to the high-voltage reference ground GND. The first preset voltage threshold is a voltage determination threshold used to measure the magnitude of this differential voltage value and thus determine whether the main negative relay 800 has become stuck.

[0143] Specifically, the detection process in this embodiment is performed with the main positive relay 200 open, the pre-charge relay 301 closed, and the main negative relay 800 open. At this time, with the main positive relay 200 open, there is no direct conductive path between the battery pack's second terminal PACK+ and the bus's second terminal LINK+; with the pre-charge relay 301 closed, the battery pack's second terminal PACK+ provides positive excitation to the bus's second terminal LINK+ via the pre-charge resistor 302; and with the main negative relay 800 open, the connection between the battery pack's first terminal PACK- and the bus's first terminal LINK- is severed.

[0144] The following explanation of the determination logic is based on the circuit structure of the aforementioned high-voltage circuit system 1000.

[0145] When the main negative relay 800 is normally disconnected, there is no conductive path between the first terminal PACK- of the battery pack and the first terminal LINK- of the bus. Because the pre-charge relay 301 is closed, the second terminal PACK+ of the battery pack charges the second terminal LINK+ of the bus via the pre-charge resistor 302, raising the potential of the second terminal LINK+. Meanwhile, because the first terminal LINK- of the bus is disconnected from the first terminal PACK- of the battery pack and cannot form a complete current loop back to the battery pack, its potential is raised along with the second terminal LINK+, thus approaching the potential of the second terminal PACK+ of the battery pack. At this time, the total voltage V inside the battery pack... 内 The voltage V corresponding to the common negative terminal reference electrical signal N When the voltage difference is close, the differential voltage value ΔU approaches 0. However, when the main negative relay 800 sticks, the first terminal of the battery pack, PACK-, is connected to the first terminal of the busbar, LINK-, through the stuck contact. The potential of the first terminal of the busbar, LINK-, is clamped to near the zero potential of the first terminal of the battery pack, PACK-, i.e., the high-voltage reference ground GND. Meanwhile, the second terminal of the battery pack, PACK+, remains at the battery pack voltage. At this time, the differential voltage value ΔU approaches the total voltage value within the battery pack. Therefore, in this embodiment, it can be determined that the main negative relay has stuck when the differential voltage value is greater than a first preset voltage threshold.

[0146] The aforementioned first preset voltage threshold can be understood as a voltage criterion used to distinguish between the first pole LINK- of the busbar being raised while suspended and the first pole LINK- of the busbar being clamped to the reference ground. The first preset voltage threshold can be set to a voltage value that is significantly higher than 0 but lower than the total voltage value in the battery pack. For example, it can be set to about half of the total voltage value in the battery pack, or it can be set to a fixed voltage value. This application does not limit this.

[0147] In this embodiment, the bus auxiliary external total voltage value can also be used to confirm whether the positive excitation is effectively established. Its specific function and judgment logic are as follows.

[0148] The bus auxiliary positive terminal electrical signal acquired by the bus auxiliary positive terminal acquisition module 1104 is used to generate the bus auxiliary external total voltage value, which represents the single-ended ground voltage of the bus second pole LINK+ relative to the high-voltage reference ground GND. After the pre-charge relay 301 is closed, if the pre-charge branch is normally conducting, the battery pack second pole PACK+ charges the bus second pole LINK+ through the pre-charge resistor 302, and the bus auxiliary external total voltage value should rise and approach the total voltage value inside the battery pack. Therefore, in this embodiment, the positive excitation can be determined first based on the bus auxiliary external total voltage value: if the bus auxiliary external total voltage value is close to the total voltage value inside the battery pack, it indicates that the pre-charge branch is conducting and the positive excitation has been established. At this time, the detection condition is met, and then the main negative relay 800 is determined to be stuck based on the relationship between the differential voltage value and the first preset voltage threshold. The determination result is more reliable. If the bus auxiliary external total voltage value is close to 0, it indicates that the pre-charge branch may not be conducting normally and the positive excitation has not been established. At this time, the detection condition is not met, and the state of the pre-charge relay 301 should be reconfirmed before detection, rather than directly determining that the main negative relay 800 is not stuck.

[0149] Optionally, according to some feasible embodiments of this application, the electrical state also includes the state of the heating branch relay sticking. Determining the electrical state of the high-voltage circuit includes the following steps: When the main positive relay is open, the precharge relay is closed, the main negative relay is closed, and the heating relay is open, the reference electrical signal of the common negative terminal is determined based on the electrical signal of the first pole of the bus relative to the high voltage reference ground. Based on the electrical signal of the heating relay relative to the high voltage reference ground and the common negative terminal reference electrical signal, a differential voltage value is generated across the heating film. The external total differential voltage value is generated based on the electrical signal of the second pole of the bus relative to the high voltage reference ground and the common negative terminal reference electrical signal. If the difference between the differential voltage value at both ends of the heating film and the total differential voltage value is greater than or equal to the second preset voltage threshold, it is determined that the heating relay has stuck.

[0150] Here, we will first explain the relevant terms involved in the testing.

[0151] A heating relay 400 is located between the first pole LINK- and the second pole LINK+ of the busbar, used to control the on / off power supply to the heating film. The positive terminal of the heating film is the high-voltage terminal between the heating relay 400 and the heating film, and the lower end of the heating film is connected to the first pole LINK- of the busbar through a heating film resistor 500. The heating film can be, for example, a positive temperature coefficient heating film, which can increase the battery pack temperature after being powered on and generating heat. The differential voltage value across the heating film refers to the differential voltage value between the voltage of the positive terminal of the heating film relative to the high-voltage reference ground GND and the voltage of the first pole LINK- of the busbar relative to the high-voltage reference ground GND, used to characterize the voltage across the heating film. The second preset voltage threshold is a voltage judgment threshold used to measure the closeness between the differential voltage value across the heating film and the total external differential voltage value, thereby determining whether the heating relay 400 has stuck.

[0152] Specifically, the detection process in this embodiment is performed with the main positive relay 200 open, the pre-charge relay 301 closed, the main negative relay 800 closed, and the heating relay 400 open. At this time, the main negative relay 800 is closed, the first terminal of the battery pack PACK- is connected to the first terminal of the bus LINK-, and the first terminal of the bus LINK- is clamped to a zero potential close to the high-voltage reference ground GND; the pre-charge relay 301 is closed, and the second terminal of the battery pack PACK+ provides positive excitation to the second terminal of the bus LINK+ through the pre-charge resistor 302; the heating relay 400 is open, and the connection between the positive terminal of the heating film and the second terminal of the bus LINK+ is cut off.

[0153] The following explanation of the determination logic is based on the circuit structure of the aforementioned high-voltage circuit system 1000.

[0154] When the heating relay 400 is normally disconnected, the connection between the positive terminal of the heating film and the second pole LINK+ of the bus is broken, and the positive terminal of the heating film is only connected to the first pole LINK- of the bus through the heating film. Since the main negative relay 800 is closed at this time, and the first pole LINK- of the bus is clamped to a zero potential close to the high-voltage reference ground GND, the positive terminal of the heating film will discharge to near 0V through the heating film. Therefore, the differential voltage value across the heating film approaches 0; while the external total differential voltage value is the voltage between the second pole LINK+ and the first pole LINK- of the bus, which approaches the total voltage value within the battery pack under the excitation of the pre-charge relay 301 closing. At this time, the difference between the two is negative. When the heating relay 400 sticks, the positive terminal of the heating film is connected to the second pole LINK+ of the bus through the stuck contact, and the positive terminal of the heating film is charged to a potential close to the second pole LINK+ of the bus. The differential voltage value across the heating film rises accordingly and approaches the external total differential voltage value, and the difference between the two approaches 0. Accordingly, in this embodiment of the application, if the difference between the differential voltage value at both ends of the heating film and the total external differential voltage value is greater than or equal to a second preset voltage threshold, it can be determined that the heating relay has stuck.

[0155] The aforementioned second preset voltage threshold can be understood as a voltage criterion used to distinguish between a disconnected heating film branch and a charged heating film branch. The second preset voltage threshold can be set to a negative value close to 0, for example, it can be set in the range of approximately -30V to 0V. The specific value can be determined comprehensively based on factors such as sampling error, and this application does not limit it in this regard.

[0156] In this embodiment, the auxiliary external total voltage value of the bus can also be used to cross-verify the external total differential voltage value. Its specific function and judgment logic are as follows.

[0157] The bus auxiliary positive terminal electrical signal acquired by the bus auxiliary positive terminal acquisition module 1104 is used to generate the bus auxiliary external total voltage value, which represents the single-ended ground voltage of the second pole LINK+ of the bus relative to the high-voltage reference ground GND. Since the main negative relay 800 is closed, the first pole LINK- of the bus is clamped to near 0V. Therefore, the external total differential voltage value should be close to the ground voltage of the second pole LINK+ of the bus, that is, it should be close to the bus auxiliary external total voltage value. In this embodiment, the external total differential voltage value can be compared with the bus auxiliary external total voltage value: if the two are close, it means that the external total differential voltage value used to determine whether the heating relay 400 is stuck is relatively accurate and reliable. At this time, the judgment is made based on the relationship between the difference between the differential voltage value at both ends of the heating film and the external total differential voltage value and the second preset voltage threshold. If the difference is large, it means that there may be an abnormality in the bus positive terminal acquisition channel or the bus auxiliary positive terminal acquisition channel. At this time, the judgment can be paused and the acquisition channel checked to avoid misjudgment caused by abnormality of the acquisition channel.

[0158] The functional blocks shown in the above block diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0159] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0160] It should be clarified that the various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. According to the embodiments described above, these embodiments do not exhaustively describe all details, nor do they limit the application to the specific embodiments described. Obviously, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to make good use of this application and modifications based on it. This application is limited only by the claims and their full scope and equivalents.

[0161] Those skilled in the art will understand that the above embodiments are exemplary and not restrictive. Different technical features appearing in different embodiments can be combined to achieve beneficial effects. Based on a study of the drawings, specification, and claims, those skilled in the art should be able to understand and implement other variations of the disclosed embodiments. In the claims, the term "comprising" does not exclude other structures; the quantity refers to "one" but does not exclude multiple; the terms "first" and "second" are used to identify names and not to indicate any particular order. Any reference numerals in the claims should not be construed as limiting the scope of protection. The appearance of certain technical features in different dependent claims does not mean that these technical features cannot be combined to achieve beneficial effects.

[0162] This document uses specific examples to illustrate the principles and implementation methods of this application. The examples are merely for the purpose of helping to understand the method and core ideas of this application. The above are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, and the existence of an infinite number of specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the concept and technical solution of this application to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A high-voltage circuit acquisition system, characterized in that, include: N acquisition modules, each with its first terminal connected to a high-voltage reference ground and its second terminal connected to the corresponding node under test, are used to acquire electrical signals of each node under test relative to the high-voltage reference ground, where N is a positive integer, and the high-voltage reference ground is connected to the first terminal of the battery pack. The calculation module is used to generate at least one of the differential voltage value between each of the nodes under test and the relative voltage value between each node under test and the high voltage reference ground, based on the electrical signal of each node under test relative to the high voltage reference ground. The node under test includes at least the first pole of the busbar, the second pole of the busbar, the second pole of the battery pack, and the positive terminal node of the heating film. The positive terminal node of the heating film is a high-voltage node between the heating relay and the heating film. The heating relay is located between the first pole of the busbar and the second pole of the busbar.

2. The system according to claim 1, characterized in that, Each of the aforementioned acquisition modules includes a first voltage divider network, an acquisition unit, a switching unit, and a second voltage divider network; The first voltage divider network includes one or more resistors connected in series. The first end of the first voltage divider network is connected to the second end of the switching unit, and the second end of the first voltage divider network is connected to the corresponding node under test. The first voltage divider network is used to divide the voltage between each node under test and the switching unit. The first terminal of the switching unit is connected to the second terminal of the second voltage divider network and the second terminal of the acquisition unit, respectively. The first terminal of the second voltage divider network is connected to the high voltage reference ground. The second voltage divider network includes one or more resistors connected in series. The second voltage divider network is used to divide the voltage between the switching unit and the high voltage reference ground. The acquisition unit is located between the switching unit and the second voltage divider network. The acquisition unit is connected to the computing module. The acquisition unit is used to acquire the electrical signal between each node under test and the high voltage reference ground, and transmit the electrical signal to the computing module.

3. The system according to claim 2, characterized in that, The N acquisition modules include a common negative terminal acquisition module, the first end of which is connected to the high voltage reference ground, and the second end of which is connected to the first pole of the busbar. The acquisition unit in the common negative terminal acquisition module is used to acquire the common negative terminal electrical signal and transmit the common negative terminal electrical signal to the calculation module. The common negative terminal electrical signal is used to characterize the voltage of the first pole of the bus relative to the high voltage reference ground.

4. The system according to claim 2, characterized in that, The N acquisition modules include a busbar positive end acquisition module, the first end of which is connected to the high voltage reference ground, and the second end of which is connected to the second pole of the busbar. The acquisition unit of the bus positive terminal acquisition module is used to acquire the bus positive terminal electrical signal and transmit the bus positive terminal electrical signal to the calculation module. The bus positive terminal electrical signal is used to characterize the voltage of the second pole of the bus relative to the high voltage reference ground. The calculation module is used to perform differential calculation on the positive terminal electrical signal of the bus and the common negative terminal electrical signal to generate an external total differential voltage value. The external total differential voltage value is used to characterize the voltage between the first pole and the second pole of the bus.

5. The system according to claim 2, characterized in that, The N acquisition modules include a battery pack positive electrode acquisition module, the second end of which is connected to the second electrode of the battery pack, and the first end of which is connected to the high voltage reference ground. The acquisition unit of the battery pack positive terminal acquisition module is used to acquire the battery pack positive terminal electrical signal and transmit the battery pack positive terminal electrical signal to the computing module. The battery pack positive terminal electrical signal is used to characterize the voltage of the second terminal of the battery pack relative to the high voltage reference ground. The calculation module is used to calculate the potential of the positive terminal electrical signal of the battery pack and the high voltage reference ground to generate the total voltage value inside the battery pack.

6. The system according to claim 2, characterized in that, The N acquisition modules include a bus auxiliary positive terminal acquisition module, the second end of which is connected to the second pole of the bus, and the first end of which is connected to the high voltage reference ground. The acquisition unit in the bus auxiliary positive terminal acquisition module is used to acquire the bus auxiliary positive terminal electrical signal and transmit the bus auxiliary positive terminal electrical signal to the calculation module. The bus auxiliary positive terminal electrical signal is used to characterize the voltage of the second pole of the bus relative to the high voltage reference ground. The calculation module is used to calculate the potential of the bus auxiliary positive terminal electrical signal and the high voltage reference ground to generate the bus auxiliary external total voltage value.

7. The system according to claim 2, characterized in that, The N acquisition modules include a heating film positive end acquisition module, the second end of which is connected to the heating relay, and the first end of which is connected to the high voltage reference ground. The acquisition unit in the heating film positive terminal acquisition module is used to acquire the heating film positive terminal electrical signal and transmit the heating film positive terminal electrical signal to the calculation module. The heating film positive terminal electrical signal is used to characterize the voltage of the heating relay relative to the high voltage reference ground. The calculation module is used to perform differential calculation on the electrical signal at the positive end of the heating film and the electrical signal at the common negative end to generate the differential voltage value at both ends of the heating film.

8. The system according to claim 1, characterized in that, The N acquisition modules include a common negative terminal acquisition module and a busbar positive terminal acquisition module; The system also includes a bias module and a reference voltage source; The bias module is disposed between the reference voltage source and the high voltage reference ground. The bias module includes a bias node. The first ends of the common negative terminal acquisition module and the bus positive terminal acquisition module are both connected to the high voltage reference ground through the bias node. The bias module is used to provide common-mode DC bias voltage to the common negative terminal acquisition module and the bus positive terminal acquisition module, respectively.

9. The system according to claim 8, characterized in that, The bias module includes at least h1 first bias resistors and h2 second bias resistors, wherein the total resistance of h1 first bias resistors is equal to the total resistance of h2 second bias resistors, and h1 and h2 are both positive integers; h1 first bias resistors are connected in series between the reference voltage source and the bias node, the second end of h1 first bias resistors is connected to the reference voltage source, and the first end of h1 first bias resistors is connected to the bias node; h2 second bias resistors are connected in series between the bias node and the high voltage reference ground, the second end of h2 second bias resistors is connected to the bias node, and the first end of h2 second bias resistors is connected to the high voltage reference ground.

10. A detection method for a high-voltage circuit system, the high-voltage circuit system comprising a high-voltage circuit acquisition system, a main positive relay, a main negative relay, a pre-charge branch, and a heating relay, characterized in that, The high-voltage circuit acquisition system includes: N acquisition modules and a processing module. The first end of each acquisition module is connected to the high-voltage reference ground, and the second end of each acquisition module is connected to the corresponding node under test. The high-voltage reference ground is connected to the first pole of the battery pack. The node under test includes at least the first pole of the busbar, the second pole of the busbar, the second pole of the battery pack, and the positive terminal node of the heating film, where N is a positive integer. The positive terminal node of the heating film is a high-voltage node between the heating relay and the heating film. The heating relay is located between the first pole of the busbar and the second pole of the busbar. The main positive relay and the pre-charge branch are connected in parallel between the second pole of the bus and the second pole of the battery pack. The pre-charge branch includes a pre-charge relay and a pre-charge resistor connected in series. The main negative relay is connected between the first pole of the battery pack and the first pole of the bus. The heating relay is connected between the first pole of the bus and the second pole of the bus. The method includes: Acquire the electrical signals of N nodes under test relative to the high-voltage reference ground; Based on the electrical signal of each node under test relative to the high-voltage reference ground, at least one of the differential voltage value between each node under test and the relative voltage value between each node under test and the high-voltage reference ground is generated; The electrical state of the high-voltage circuit is determined based on at least one of the differential voltage value and the relative voltage value.

11. The method according to claim 10, characterized in that, The electrical state includes the sticking state of the bus positive circuit relay; Determining the electrical state of the high-voltage circuit includes: When the main positive relay, the precharge relay and the main negative relay are all disconnected, the common negative terminal reference electrical signal is determined based on the electrical signal of the first pole of the bus relative to the high voltage reference ground. An external total differential voltage value is generated based on the electrical signal of the second pole of the bus relative to the high voltage reference ground and the reference electrical signal of the common negative terminal; The total voltage value inside the battery pack is determined based on the electrical signal of the second pole of the battery pack relative to the high voltage reference ground; If the difference between the external total differential voltage value and the total voltage value inside the battery pack is greater than or equal to a preset difference threshold, it is determined that at least one of the main positive relay and the precharge relay is stuck together.

12. The method according to claim 10, characterized in that, The electrical state includes the sticking state of the bus negative circuit relay; Determining the electrical state of the high-voltage circuit includes: When the main positive relay is open, the precharge relay is closed, and the main negative relay is open, the common negative terminal reference electrical signal is determined based on the electrical signal of the first pole of the bus relative to the high voltage reference ground. A differential voltage value is generated based on the electrical signal of the second terminal of the battery pack relative to the high voltage reference ground and the reference electrical signal of the common negative terminal; If the differential voltage value is greater than a first preset voltage threshold, it is determined that the main negative relay has become stuck.

13. The method according to claim 10, characterized in that, The electrical condition includes the heating branch relay sticking. Determining the electrical state of the high-voltage circuit includes: When the main positive relay is open, the precharge relay is closed, the main negative relay is closed, and the heating relay is open, the common negative terminal reference electrical signal is determined based on the electrical signal of the first pole of the bus relative to the high voltage reference ground. Based on the electrical signal of the heating relay relative to the high-voltage reference ground and the common negative terminal reference electrical signal, a differential voltage value is generated across the heating film. An external total differential voltage value is generated based on the electrical signal of the second pole of the bus relative to the high voltage reference ground and the reference electrical signal of the common negative terminal; If the difference between the differential voltage value at both ends of the heating film and the total external differential voltage value is greater than or equal to the second preset voltage threshold, it is determined that the heating relay has become stuck.

Images