CAN communication circuit of battery management system and battery management system

Abstract

This disclosure relates to the field of battery management technology, and more specifically, to a CAN communication circuit for a battery management system and a battery management system. The CAN communication circuit of the battery management system includes a connector, a terminating resistor circuit, a CAN transceiver, and a controller connected in sequence. The terminating resistor circuit includes a CAN_H line, a CAN_L line, a first resistor, a second resistor, and a first capacitor. The CAN_H line, the first resistor, the first capacitor, and a ground terminal are connected in sequence, and the second resistor is connected to the CAN_L line. The connector includes a first port and a second port. The first port is connected to the first resistor and the first capacitor, and the second port is connected to the second resistor. When the battery management system is located at the end of a CAN bus system, the first port and the second port are connected.

Description

Technical Field

[0001] This disclosure relates to the field of battery management technology, and more specifically, to a CAN communication circuit for a battery management system and a battery management system. Background Technology

[0002] The Battery Management System (BMS) is an essential component of new energy vehicles, used for monitoring and managing batteries. Its main functions include detecting battery parameters such as voltage, current, and temperature; using appropriate algorithms to estimate and monitor battery capacity and SOC; receiving vehicle commands to control contactors during power-on, power-off, and charging processes; and performing battery equalization.

[0003] As the primary communication method between different control units within a vehicle, the CAN bus is used by the Battery Management System (BMS) to receive commands and send battery-related information. In the CAN bus, if the BMS is placed at a terminal node, a terminating resistor is required for impedance matching to reduce the impact of parasitic parameters in the communication harness and ensure stable CAN communication. However, if placed at an intermediate node, a terminating resistor cannot be placed to avoid affecting the communication of other nodes on the CAN bus. In current new energy vehicles, the variety of models is increasing, and the arrangement of various control modules and battery packs within the vehicle is also becoming more diverse. As one of the nodes on the CAN bus, the BMS may be placed at a terminal or in a non-terminal position within the vehicle. Currently, no single BMS can accommodate both scenarios simultaneously. This necessitates automakers using multiple BMS systems, increasing production management and maintenance costs. Summary of the Invention

[0004] One object of this disclosure is to provide a CAN communication circuit for a battery management system that solves the problem that BMS cannot be simultaneously applied to both CAN system terminals and non-terminals.

[0005] According to one aspect of this disclosure, a CAN communication circuit for a battery management system is provided, comprising a connector, a terminating resistor circuit, a CAN transceiver, and a controller connected in sequence.

[0006] The terminating resistor circuit includes a CAN_H line, a CAN_L line, a first resistor, a second resistor, and a first capacitor. The CAN_H line, the first resistor, the first capacitor, and the ground terminal are connected in sequence, and the second resistor is connected to the CAN_L line.

[0007] The connector includes a first port and a second port, the first port being connected to the first resistor and the first capacitor, and the second port being connected to the second resistor;

[0008] When the battery management system is located at the terminal of the CAN bus system, the first port and the second port are connected.

[0009] Optionally, the connector further includes a CAN_H port and a CAN_L port, which are connected to the CAN_H line and the CAN_L line, respectively.

[0010] Optionally, the circuit further includes a connection detection circuit, which is connected to the terminating resistor circuit and the controller respectively, and the controller determines whether the terminating resistor is working properly through the connection detection circuit.

[0011] Optionally, the connection detection circuit includes: a first switching transistor, a second switching transistor, a first optocoupler, and a second optocoupler;

[0012] The first switching transistor is connected to the light emitter of the first optocoupler and the I / O port of the controller. The first switching transistor is turned on under the control of the controller so that the light emitter of the first optocoupler emits light.

[0013] The first end of the photodetector of the first optocoupler is connected to the CAN_L line, and the second end, the third resistor and the ground end of the photodetector of the first optocoupler are connected in sequence. The voltage acquisition port of the controller is connected to the second end of the photodetector.

[0014] The second switch is connected to the light emitter of the second optocoupler and the I / O port of the controller. The second switch is turned on under the control of the controller so that the light emitter of the second optocoupler emits light.

[0015] The first end of the photodetector of the second optocoupler is connected to the power supply, and the second end of the photodetector of the second optocoupler is connected to the CAN_H line.

[0016] Optionally, the terminating resistor circuit further includes a fourth resistor, a fifth resistor, and a second capacitor. The CAN_H line, the fourth resistor, the second capacitor, and the ground terminal are connected in sequence, and the fifth resistor is connected to the CAN_L line.

[0017] The fourth resistor and the fifth resistor are connected based on the control of the controller.

[0018] Optionally, the battery management system further includes a resistor control circuit, one end of which is connected between the fourth resistor and the second capacitor, and the other end of which is connected to the fifth resistor.

[0019] The resistor control circuit is connected to the controller, and the controller controls the fourth and fifth resistors as terminating resistors through the resistor control circuit.

[0020] Optionally, the resistor control circuit includes: a third switching transistor and a third optocoupler;

[0021] The third switch is connected to the light emitter of the third optocoupler and the I / O port of the controller respectively. The third switch is turned on under the control of the controller so that the light emitter of the first optocoupler emits light.

[0022] The first end of the photodetector of the third optocoupler is connected between the fourth resistor and the second capacitor, and the second end of the photodetector of the third optocoupler is connected to the fifth resistor.

[0023] Optionally, if the battery management system is not located at an intermediate node of the CAN bus system, the first port and the second port are not connected.

[0024] Optionally, the CAN communication circuit of the battery management system implements the following operating modes under the control of the controller;

[0025] In the detection mode, the controller controls the first and second switching transistors to be turned on and the third switching transistor to be turned off, so as to detect the voltage value of the third resistor and determine the connection state of the first and second resistors based on the voltage value.

[0026] Normal operating mode, corresponding to the normal operating mode, when the connection state of the first resistor and the second resistor is normal, controls the first switch, the second switch and the third switch to be disconnected;

[0027] An abnormal operating mode, corresponding to the normal operating mode, involves controlling the first and second switching transistors to disconnect and the third switching transistor to close when the connection state of the first and second resistors is abnormal.

[0028] According to a second aspect of this disclosure, a battery management system is provided, including the CAN communication circuit of the battery management system as described in any of the first aspects.

[0029] One technical advantage of this disclosure is that it provides a CAN communication circuit for a battery management system, including a connector, a terminating resistor circuit, a CAN transceiver, and a controller connected in sequence. The CAN_H line, the first resistor, the first capacitor, and the ground terminal in the terminating resistor circuit are connected in sequence, and the second resistor is connected to the CAN_L line. The connector includes a first port connected to the first resistor and the first capacitor, and a second port connected to the second resistor; when the battery management system is located at the end of a CAN bus system, the first port and the second port are connected. Through the above-described CAN communication circuit for the battery management system, when the battery management system is located at the end of a CAN bus system, the first and second resistors can be connected to the CAN bus as terminating resistors, ensuring stable CAN communication. This allows the battery management system to be located at either the end or non-end of the bus system.

[0030] Other features and advantages of the embodiments of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0031] The accompanying drawings, which form part of this specification, illustrate embodiments of the present disclosure and, together with the specification, serve to explain the principles of the embodiments of the present disclosure.

[0032] Figure 1 This is a schematic diagram of the CAN communication circuit of a battery management system according to one embodiment;

[0033] Figure 2 This is a schematic diagram of the CAN communication circuit of a battery management system according to another embodiment;

[0034] Figure 3 This is a schematic diagram of the connection detection circuit according to one embodiment;

[0035] Figure 4 This is a schematic diagram of a resistor control circuit according to one embodiment;

[0036] Explanation of reference numerals in the attached figures

[0037] First resistor R1, second resistor R2, third resistor R3, fourth resistor R4, fifth resistor R5, first capacitor C1, second capacitor C2, first switch Q1, second switch Q2, third switch Q3, first optocoupler U3, second optocoupler U4, third optocoupler U5; Detailed Implementation

[0038] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0039] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0040] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0041] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0042] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0043] This application discloses a CAN communication circuit for a battery management system, including a connector P1, a terminating resistor circuit, a CAN transceiver U1, and a controller MCU connected in sequence. The terminating resistor circuit includes a CAN_H line, a CAN_L line, a first resistor R1, a second resistor R2, and a first capacitor C1. The CAN_H line, the first resistor R1, the first capacitor C1, and a ground terminal are connected in sequence, and the second resistor R2 is connected to the CAN_L line. The connector P1 includes a first port and a second port. The first port is connected to the first resistor R1 and the first capacitor C1, and the second port is connected to the second resistor R2. When the battery management system is located at the end of a CAN bus system, the first port and the second port are connected.

[0044] In this embodiment, the BMS's CAN communication circuit includes connector P1, through which the battery management system can access an external CAN bus system. This CAN communication circuit includes connector P1, a terminating resistor circuit, a CAN transceiver U1, and a controller MCU connected in sequence. In this example, the terminating resistor circuit includes CAN_H and CAN_L lines, and connects both connector P1 and the CAN transceiver U1. When connector P1 is connected to the CAN bus system, the CAN transceiver U1 can receive data from the CAN bus system based on this connection and forward it to the connected controller MCU, or convert the data sent by the controller MCU into electrical signals and send them out through the connection.

[0045] In one example of this embodiment, connector P1 further includes a CAN_H port and a CAN_L port, which are connected to the CAN_H line and the CAN_L line, respectively.

[0046] like Figure 1 As shown, connector P1 includes a CAN_H port and a CAN_L port, which are respectively connected to the CAN_H line and CAN_L line in the CAN communication circuit of the battery management system. The BMS can connect to an external CAN bus system through connector P1. For example, the CAN_H port can be connected to the CAN_H line of an external CAN bus system, and the CAN_L port can be connected to the CAN_L line of an external CAN bus system.

[0047] In an embodiment, such as Figure 1 As shown, in the terminating resistor circuit, the CAN_H line, the first resistor R1, the first capacitor C1, and the ground terminal are connected in sequence. Simultaneously, the first resistor R1 and the first capacitor C1 are also connected to the first port of connector P1. The terminating resistor circuit also includes a second resistor R2, with its two ends connected to the CAN_L line and the second port, respectively.

[0048] In this embodiment, when the battery management system is located at the terminal of the CAN bus system, the first and second ports of the CAN communication circuit of the battery management system can be connected. For example, the first and second ports of connector P1, or their corresponding ports on the other end, can be connected via a wiring harness. In another example, a relay, switching transistor, or other switching device can be installed on the connection line between the first and second ports, which can be opened or closed based on the control of the controller MCU. When the battery management system is located at the terminal of the CAN bus system, the controller MCU controls its closure accordingly, connecting the terminating resistor. The first resistor R1 and the second resistor R2 are connected to the CAN bus as terminating resistors, forming an RC filter with the first capacitor C1 to filter common-mode interference on the bus, ensuring stable CAN communication.

[0049] In another embodiment of this example, when the battery management system is located at the intermediate node of the CAN bus system, the first port and the second port are not connected.

[0050] In this embodiment, when the battery management system is located at an intermediate node of the CAN bus system, i.e., at a non-terminal position, the first and second ports of the CAN communication circuit of the battery management system do not need to be connected. For example, the first and second ports of connector P1, or their corresponding ports on the other end, can be connected without using a wiring harness. In another example, a relay, switching device, or other switching device can be provided on the connection line between the first and second ports, which can be opened or closed based on the control of the controller MCU. When the battery management system is located at an intermediate node of the CAN bus system, the controller MCU controls it to be opened, so that the terminating resistor is not connected to the CAN bus.

[0051] In this embodiment, as Figure 2 As shown, a third and a fourth capacitor can be set on the CAN_H and CAN_L lines as line filter capacitors. At the same time, a common-mode inductor can also be set to filter out radiated noise from the CAN transceiver U1 or noise entering the CAN transceiver U1 from the bus.

[0052] In this example, a CAN communication circuit for a battery management system is provided, including a connector P1, a terminating resistor circuit, a CAN transceiver U1, and a controller MCU connected in sequence. The CAN_H line, the first resistor R1, the first capacitor C1, and the ground terminal in the terminating resistor circuit are connected in sequence, and the second resistor R2 is connected to the CAN_L line. The connector P1 includes a first port connected to the first resistor R1 and the first capacitor C1, and a second port connected to the second resistor R2; when the battery management system is set as a terminal of the CAN bus system, the first port and the second port are connected. Through the above-described CAN communication circuit for the battery management system, when the battery management system is set as a terminal of the CAN bus system, the first resistor R1 and the second resistor R2 can be connected to the CAN bus as terminating resistors, ensuring stable CAN communication. This allows the battery management system to be set as a terminal or non-terminal of the bus system.

[0053] In one example of this embodiment, the circuit further includes a connection detection circuit, which is connected to both the terminating resistor circuit and the controller MCU. The controller MCU determines whether the terminating resistor is working properly through the connection detection circuit.

[0054] like Figure 2 As shown, the CAN communication circuit also includes a connection detection circuit. The two ends of the connection detection circuit are connected to the terminating resistor circuit and the controller MCU, respectively. Specifically, the connection detection circuit can be connected to CAN_H and CAN_L in the terminating circuit. The controller MCU can use this connection detection circuit to detect whether the terminating resistor is connected and whether it is working properly.

[0055] In this embodiment, the connection detection circuit includes: a first switch Q1, a second switch Q2, a first optocoupler U3, and a second optocoupler U4; the first switch Q1 is connected to the emitter of the first optocoupler U3 and the I / O port of the controller MCU, and the first switch Q1 is turned on under the control of the controller MCU to make the emitter of the first optocoupler U3 emit light; the first end of the light receiver of the first optocoupler U3 is connected to the CAN_L line, the second end of the light receiver of the first optocoupler U3, the third resistor R3, and the ground terminal are connected in sequence, and the voltage acquisition port of the controller MCU is connected to the second end of the light receiver; the second switch Q2 is connected to the emitter of the second optocoupler U4 and the I / O port of the controller MCU, and the second switch Q2 is turned on under the control of the controller MCU to make the emitter of the second optocoupler U4 emit light; the first end of the light receiver of the second optocoupler U4 is connected to the power supply, and the second end of the light receiver of the second optocoupler U4 is connected to the CAN_H line.

[0056] In this embodiment, the first switch Q1 and the second switch Q2 can be transistors, MOSFETs, or other similar switching transistors. The first switch Q1 and the second switch Q2 are respectively connected to the MCU's I / O ports, and are turned on or off via the I / O ports. In one example, such as... Figure 3 As shown, the first switch Q1 and the second switch Q2 are NMOS transistors. The gates of both transistors are electrically connected to the I / O port. The drain of the first switch Q1 is connected to the light emitter of the first optocoupler U3, and the drain of the second switch Q2 is connected to the light emitter of the second optocoupler U4. The sources of both transistors are grounded. In this embodiment, the other ends of the light emitters of the first optocoupler U3 and the second optocoupler U4 can be connected to a system power supply, i.e. Figure 3 With a 5V power supply, when the switching transistor is turned on, current flows through the LED, causing it to emit light.

[0057] In this embodiment, the first switch Q1, the second switch Q2, and the emitter of the first optocoupler U3 can all be equipped with corresponding current-limiting resistors, capacitors, pull-up resistors, etc. For example... Figure 3 The numbers R8, R6, R7, R9, R10, R11, C5, and C6 are among them.

[0058] In this embodiment, as Figure 3 As shown, the photodetectors of the first optocoupler U3 and the second optocoupler U4 can be photosensitive devices such as phototransistors and photodiodes. One end of the photodetector of the first optocoupler U3 is connected to the CAN_L line, and the other end is connected to the third resistor R3 and the ground terminal in sequence. The voltage acquisition port of the controller MCU is connected to the third resistor R3 to acquire the voltage of the third resistor R3. One end of the photodetector of the second optocoupler U4 is connected to the power supply. Figure 3One end is connected to a 3.3V power supply, and the other end is connected to the CAN_H line. When the CAN communication circuit of the battery management system is connected to the terminating resistor, that is, when R1 and R2 are directly connected, the controller MCU can control the first switch Q1 and the second switch Q2 to conduct, so that the 3.3V power supply can supply power to the circuit of R1, R2, and R3. At this time, the MCU's AD port can collect the voltage of the third resistor R3 and determine the resistance value and connection status of R1 and R2 based on this voltage.

[0059] It should be noted that the voltage of each power supply connected to the detection circuit can be set based on the actual device and system requirements.

[0060] In this example, the CAN communication circuit may also include a connection detection circuit to detect whether the system's terminating resistor is connected, so that problems with the terminating resistor can be detected in time, ensuring the quality of CAN communication.

[0061] In one example of this embodiment, the terminating resistor circuit further includes a fourth resistor R4, a fifth resistor R5, and a second capacitor. The CAN_H line, the fourth resistor R4, the second capacitor, and the ground terminal are connected in sequence, and the fifth resistor R5 is connected to the CAN_L line. The fourth resistor R4 and the fifth resistor R5 are connected based on the control of the controller MCU.

[0062] In the terminating resistor circuit, the CAN_H line, the fourth resistor R4, the second capacitor, and the ground terminal are connected sequentially. Simultaneously, the fourth resistor R4 and the first capacitor C1 are also connected to the first port of connector P1. The terminating resistor circuit also includes a fifth resistor R5, which is connected to the CAN_L line. In this example, the fourth resistor R4 and the fifth resistor R5 are also connected based on the control of the controller MCU. For example, a connection circuit with a switching device can be provided between the fourth and fifth resistors R5, allowing them to be connected under the control of the MCU.

[0063] In this example, if there is a problem with the connection of the first resistor R1 and the second resistor R2, the controller can control the connection of the fourth resistor R4 and the fifth resistor R5 to continue communication as terminating resistors.

[0064] In one example of this embodiment, the battery management system further includes a resistor control circuit. One end of the resistor control circuit is connected between the fourth resistor R4 and the second capacitor, and the other end is connected to the fifth resistor R5. The resistor control circuit is connected to the controller MCU, which controls the fourth resistor R4 and the fifth resistor R5 as terminating resistors.

[0065] like Figure 2As shown, the battery management system also includes a resistor control circuit, which is located between the fourth resistor R4 and the fifth resistor R5. The resistor control circuit is also connected to the controller MCU, and can control the fourth resistor R4 and the fifth resistor R5 to connect to the CAN communication circuit under the control of the controller MCU, so as to serve as terminating resistors to ensure communication.

[0066] In one example of this embodiment, the resistor control circuit includes: a third switch Q3 and a third optocoupler U5; the third switch Q3 is connected to the emitter of the third optocoupler U5 and the IO port of the controller MCU respectively, and the third switch Q3 is turned on under the control of the controller MCU so that the emitter of the first optocoupler U3 emits light; the first end of the light receiver of the third optocoupler U5 is connected to the fourth resistor R4 and the second capacitor, and the second end of the light receiver of the third optocoupler U5 is connected to the fifth resistor R5.

[0067] In this embodiment, the third switch Q3 can be a transistor, MOSFET, or other similar type of switch. The third switch Q3 is connected to the MCU's I / O port, and the MCU controls the switch to turn it on or off via the I / O port. In one example, such as... Figure 4 As shown, the third switch Q3 is an NMOS transistor. The gate of the third switch Q3 is electrically connected to the I / O port, the drain of the third switch Q3 is connected to the emitter of the third optocoupler U5, and the source of the third switch Q3 is grounded. In this embodiment, the other end of the emitter of the third optocoupler U5 can be connected to a system power supply, i.e. Figure 4 With a 5V power supply, when the switching transistor is turned on, current flows through the LED, causing it to emit light.

[0068] In this embodiment, as Figure 4 As shown, the photodetector of the third optocoupler U5 can be a photosensitive device such as a phototransistor or photodiode. One end of the photodetector of the third optocoupler U5 is connected to the fifth resistor R5, and the other end is connected to the position between the fourth resistor R4 and the second capacitor. The controller MCU can control the third switch Q3 to conduct, so that the fourth resistor R4 and the fifth resistor R5 are connected and connected to the CAN communication circuit as a terminating resistor.

[0069] In this embodiment, when the original terminating resistors of the system, namely the first resistor R1 and the second resistor R2, fail or cannot be connected to the CAN communication circuit, the controller MCU can control the third switch Q3 to turn on, so that the fourth resistor R4 and the fifth resistor R5 can be connected to the CAN communication circuit as terminating resistors to continue to ensure circuit communication, thereby reducing production management costs and maintenance costs.

[0070] In one example of this embodiment, the CAN communication circuit of the battery management system implements the following operating modes under the control of the controller MCU: Detection mode, in which the controller MCU controls the first switch Q1 and the second switch Q2 to be turned on, and the third switch Q3 to be turned off, to detect the voltage value of the third resistor R3, and determine the connection state of the first resistor R1 and the second resistor R2 based on the voltage value; Normal operating mode, in which the first switch Q1, the second switch Q2, and the third switch Q3 are turned off when the connection state of the first resistor R1 and the second resistor R2 is normal; Abnormal operating mode, in which the first switch Q1 and the second switch Q2 are turned off and the third switch Q3 is turned on when the connection state of the first resistor R1 and the second resistor R2 is abnormal.

[0071] In this embodiment, after the CAN communication circuit of the battery management system is connected to the CAN bus system, especially after the BMS is connected to the terminal of the CAN bus system, the battery management system can operate in a corresponding working mode. For example, after connecting to the CAN bus system, before performing CAN communication, the controller MCU can first enter the detection mode, turning on the first switch Q1 and the second switch Q2, and turning off the third switch Q3. By detecting the voltage across the third resistor R3 in the circuit of the first resistor R1, the second resistor R2, and the third resistor R3, the voltage values ​​of the first resistor R1 and the second resistor R2 are determined, thereby determining whether the first resistor R1 and the second resistor R2 are connected to the circuit.

[0072] When the first resistor R1 and the second resistor R2 are properly connected, the controller MCU can enter the normal operating mode, causing all three switches Q3 to be disconnected, and the first resistor R1 and the second resistor R2 can communicate normally. When the first resistor R1 and the second resistor R2 are not properly connected, the controller MCU can enter the abnormal operating mode, controlling the first switch Q1 and the second switch Q2 to be disconnected, and the third switch Q3 to be closed. This allows the fourth resistor R4 and the fifth resistor R5 to be connected in the circuit as terminating resistors to reduce the influence of parasitic parameters in the communication harness and ensure normal and stable CAN communication.

[0073] This application also provides a battery management system, including a CAN communication circuit for the battery management system. Any of the CAN communication circuits of the battery management system embodiments can achieve the same technical effect, and will not be described again here to avoid repetition.

[0074] The various embodiments in this disclosure are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the device and apparatus embodiments are basically similar to the method embodiments, so the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0075] The foregoing has described specific embodiments of this disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0076] Embodiments of this disclosure may be systems, methods, and / or computer program products. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of the embodiments of this disclosure.

[0077] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination thereof. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0078] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0079] Computer program instructions used to perform the operations of embodiments of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on a user's computer, partially on a user's computer, as a standalone software package, partially on a user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing state information from the computer-readable program instructions. This electronic circuitry can execute the computer-readable program instructions to implement various aspects of embodiments of this disclosure.

[0080] Various aspects of embodiments of this disclosure are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0081] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when executed by the processor of the computer or other programmable data processing apparatus, they create means for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, programmable data processing apparatus, and / or other device to operate in a particular manner; thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0082] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0083] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction, which contains one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions. It will be known to those skilled in the art that implementation in hardware, implementation in software, and implementation in a combination of software and hardware are equivalent.

[0084] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A CAN communication circuit for a battery management system, characterized in that, It includes connectors, terminating resistor circuits, CAN transceivers, and controllers connected in sequence; The terminating resistor circuit includes a CAN_H line, a CAN_L line, a first resistor, a second resistor, and a first capacitor. The CAN_H line, the first resistor, the first capacitor, and the ground terminal are connected in sequence, and the second resistor is connected to the CAN_L line. The connector includes a first port and a second port, the first port being connected to the first resistor and the first capacitor, and the second port being connected to the second resistor; The connector also includes a CAN_H port and a CAN_L port, which are respectively connected to the CAN_H line and the CAN_L line; When the battery management system is located at the terminal of the CAN bus system, the first port and the second port are connected. When the battery management system is located at the intermediate node of the CAN bus system, the first port and the second port are not connected.

2. The circuit according to claim 1, characterized in that, The circuit also includes a connection detection circuit, which is connected to the terminating resistor circuit and the controller respectively. The controller determines whether the terminating resistor is working properly through the connection detection circuit.

3. The circuit according to claim 2, characterized in that, The connection detection circuit includes: a first switching transistor, a second switching transistor, a first optocoupler, and a second optocoupler; The first switching transistor is connected to the light emitter of the first optocoupler and the I / O port of the controller. The first switching transistor is turned on under the control of the controller so that the light emitter of the first optocoupler emits light. The first end of the photodetector of the first optocoupler is connected to the CAN_L line, and the second end, the third resistor and the ground end of the photodetector of the first optocoupler are connected in sequence. The voltage acquisition port of the controller is connected to the second end of the photodetector. The second switch is connected to the light emitter of the second optocoupler and the I / O port of the controller. The second switch is turned on under the control of the controller so that the light emitter of the second optocoupler emits light. The first end of the photodetector of the second optocoupler is connected to the power supply, and the second end of the photodetector of the second optocoupler is connected to the CAN_H line.

4. The circuit according to claim 3, characterized in that, The terminating resistor circuit also includes a fourth resistor, a fifth resistor, and a second capacitor. The CAN_H line, the fourth resistor, the second capacitor, and the ground terminal are connected in sequence, and the fifth resistor is connected to the CAN_L line. The fourth resistor and the fifth resistor are connected based on the control of the controller.

5. The circuit according to claim 4, characterized in that, The battery management system further includes a resistor control circuit, one end of which is connected between the fourth resistor and the second capacitor, and the other end of which is connected to the fifth resistor. The resistor control circuit is connected to the controller, and the controller controls the fourth and fifth resistors as terminating resistors through the resistor control circuit.

6. The circuit according to claim 5, characterized in that, The resistor control circuit includes: a third switching transistor and a third optocoupler; The third switch is connected to the light emitter of the third optocoupler and the I / O port of the controller respectively. The third switch is turned on under the control of the controller so that the light emitter of the first optocoupler emits light. The first end of the photodetector of the third optocoupler is connected between the fourth resistor and the second capacitor, and the second end of the photodetector of the third optocoupler is connected to the fifth resistor.

7. The circuit according to claim 6, characterized in that, The CAN communication circuit of the battery management system implements the following working modes under the control of the controller; In the detection mode, the controller controls the first and second switching transistors to be turned on and the third switching transistor to be turned off, so as to detect the voltage value of the third resistor and determine the connection state of the first and second resistors based on the voltage value. Normal operating mode, corresponding to the normal operating mode, when the connection state of the first resistor and the second resistor is normal, controls the first switch, the second switch and the third switch to be disconnected; An abnormal operating mode, corresponding to the abnormal operating mode, is to control the first switch and the second switch to disconnect and control the third switch to close when the connection state of the first resistor and the second resistor is abnormal.

8. A battery management system, characterized in that, Includes the CAN communication circuit of the battery management system as described in any one of claims 1-7.

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