CAN bus communication circuit and power electronic conversion equipment
Through the integrated CAN communication unit and diode unidirectional signal transmission technology, the problem of space and resources occupied by multi-CAN transceiver solutions is solved, and the effect of reducing power consumption and system complexity is achieved.
Patent Information
- Application Number
- CN202421842845.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-31
- Publication Date
- 2025-05-20
- Estimated Expiration
- 2034-07-31
AI Technical Summary
In the prior art, the multi-CAN transceiver solution occupies a large amount of physical space and resources, increasing signal delay and power consumption, and at the same time, the system complexity and cost are also high.
The integrated CAN communication unit is adopted to ensure unidirectional transmission of signals through diodes, reduce signal delay, and connect all processors through shared CANTX and CANRX buses to reduce physical space and resource usage.
It realizes saving physical space and resources, reducing system complexity and cost, while reducing power consumption and signal delay.
Smart Images
Figure CN222888081U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of CAN bus communication, and particularly to a CAN bus communication circuit and a power electronic conversion device. Background Art
[0002] On the control board of a photovoltaic inverter or an energy storage converter, there are usually two Digital Signal Processors (DSPs for short) and a Complex Programmable Logic Device (CPLD for short). These two DSPs are responsible for processing a large amount of detection data and performing complex control tasks, while the CPLD is used to implement various logic and protection functions, such as signal processing, data transmission, driving timing, protection logic, etc. In addition, between these two DSPs and other circuit boards of the inverter (such as a human-machine interaction circuit board, an arc detection board, an anti-PID board, etc.), they can be connected through CAN communication to achieve sharing, exchange, and control of data and information.
[0003] In the prior art, two or more CAN transceiver signals on the control board are usually sent and received through their respective CAN transceivers, that is, there are as many CAN transceivers as there are processors. These CAN transceivers are responsible for converting digital signals into differential bus signals for communication with other devices through the CAN bus.
[0004] However, the above prior art has some problems in practical applications. First, each CAN transceiver needs to occupy a certain amount of physical space and resources, which is a relatively large burden for a control board with limited space and resources. Second, each CAN transceiver will increase the signal delay, which will have a certain impact on the communication rate, and at the same time increase the power consumption. Finally, since each CAN transceiver needs to perform independent signal processing and conversion, it increases the complexity and cost of the system.
[0005] In view of the above problems, no effective solution has been proposed yet. Summary of the Utility Model
[0006] Embodiments of the present application provide a CAN bus communication circuit and a power electronic conversion device to at least solve the technical problems that the traditional multi-CAN transceiver solution occupies a large amount of physical space and resources, and has high power consumption and cost.
[0007] According to one aspect of the embodiments of the present application, a CAN bus communication circuit is provided, including: a CAN communication unit; wherein, the TX end of the CAN communication unit is connected to the CANTX bus, and the RX end of the CAN communication unit is connected to the CANRX bus through a diode; at least one communication port for connecting to a processor unit, the communication port including the TX end and the RX end of the processor unit; wherein, one end of a first target diode is respectively connected to the CANRX bus and the RX end of the processor unit, and the common end where the other end of the first target diode is connected to one end of a second target diode is connected to the TX end of the processor unit, and the other end of the second target diode is connected to the CANTX bus.
[0008] Optionally, it further includes a first resistor and a second resistor; wherein, one end of the first resistor is connected to a power supply, and the other end of the first resistor is connected to the CANTX bus; one end of the second resistor is connected to the power supply, and the other end of the second resistor is connected to the CANRX bus.
[0009] Optionally, the positive electrode of the diode is connected to the CANRX bus, and the negative electrode of the diode is connected to the RX end of the CAN communication unit.
[0010] Optionally, the positive electrode of the first target diode is connected to the CANRX bus, the negative electrode of the first target diode is connected to the negative electrode of the second target diode, and the positive electrode of the second target diode is connected to the CANTX bus.
[0011] Optionally, the CAN communication unit includes at least two CAN transceivers; wherein, the CANH end of the CAN transceiver is connected to the CANH bus, and the CANL end of the CAN transceiver is connected to the CANL bus.
[0012] Optionally, the CAN communication unit includes a first CAN transceiver, and the first CAN transceiver is any one of the at least two CAN transceivers; wherein, the TX end of the first CAN transceiver is connected to the CANTX bus, and the RX end of the first CAN transceiver is connected to the CANRX bus through a diode.
[0013] Optionally, the CAN communication unit includes a second CAN transceiver, and the second CAN transceiver is any one of the at least two CAN transceivers other than the first CAN transceiver; wherein, the TX end of the second CAN transceiver is used to connect to the TX end of other devices, and the RX end of the second CAN transceiver is used to connect to the RX end of other devices.
[0014] According to another aspect of the embodiments of the present application, a power electronic conversion device is provided. A complex programmable logic device and multiple processor units are provided on the control board of the power electronic conversion device. The complex programmable logic device includes the CAN bus communication circuit as described above.
[0015] Optionally, the processor unit includes a digital signal processor or a microcontroller unit.
[0016] Optionally, the power electronic conversion device includes a photovoltaic inverter or an energy storage converter.
[0017] In the embodiments of the present application, the CAN bus communication circuit uses an integrated CAN communication unit. This unit is responsible for all the CAN communication tasks of the processors, rather than equipping each processor with a separate CAN transceiver. By using diodes (such as the first target diode D1 and the second target diode D2) between the CAN communication unit and the processors, unidirectional signal transmission is ensured, signal reflux is prevented, the signal path is simplified, and signal delay is reduced. All the processors are connected to the CAN communication unit through the shared CANTX and CANRX buses, which reduces the required physical space and resources, while reducing the system complexity and cost, thus solving the technical problems of the traditional multi-CAN transceiver solution occupying a large amount of physical space and resources, as well as high power consumption and cost, and achieving the technical effects of saving physical space and resources, and reducing power consumption and cost. Description of the Drawings
[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other embodiments can be obtained based on these drawings without creative efforts.
[0019] Figure 1 Schematic diagram of a CAN bus communication circuit provided by an embodiment of the present application;
[0020] Figure 2 Schematic diagram of another CAN bus communication circuit provided by an embodiment of the present application;
[0021] Figure 3 Schematic diagram of the power electronic conversion device provided by an embodiment of the present application. Detailed Embodiments
[0022] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following will refer to the drawings and combine the embodiments to detail the present application.
[0023] Note that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0024] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and values set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed herein, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.
[0025] According to one aspect of the embodiments of the present application, a CAN bus communication circuit is provided. Figure 1 A schematic diagram of a CAN bus communication circuit provided by an embodiment of the present application, as Figure 1 shown, the CAN bus communication circuit includes:
[0026] A CAN communication unit T; wherein, the TX end of the CAN communication unit T is connected to the CAN TX bus, and the RX end of the CAN communication unit T is connected to the CAN RX bus through a diode D1;
[0027] At least one communication port for connecting to a processor unit, the communication port including the TX end (such as TX_1, TX_2,..., TX_n) and the RX end (such as RX_1, RX_2,..., RX_n) of the processor unit; wherein, one end of the first target diodes (such as D2, D4,..., D2n) are respectively connected to the CAN RX bus and the RX end of the processor unit, and the common end where the other ends of the first target diodes (such as D2, D4,..., D2n) are connected to one end of the second target diodes (such as D3, D5,..., D2n+1) is connected to the TX end (such as TX_1, TX_2,..., TX_n) of the processor unit, and the other ends of the second target diodes (such as D3, D5,..., D2n+1) are connected to the CAN TX bus.
[0028] Among them, when the processor unit is the first processor unit, the TX end of the first processor unit is TX_1, the RX end is RX_1, the first target diode is D2, and the second target diode is D3; when the processor unit is the second processor unit, the TX end of the second processor unit is TX_2, the RX end is RX_2, the first target diode is D4, and the second target diode is D5; and so on. When the processor unit is the nth processor unit, the TX end of the nth processor unit is TX_n, the RX end is RX_n, the first target diode is D2n, and the second target diode is D2n + 1.
[0029] In the embodiment of the present application, the CAN bus communication circuit adopts an integrated CAN communication unit, which is responsible for all CAN communication tasks of all processors, rather than equipping each processor with a separate CAN transceiver. By using diodes (such as the first target diode D1 and the second target diode D2) between the CAN communication unit and the processor, the unidirectional transmission of signals is ensured, signal backflow is prevented, the signal path is simplified, and signal delay is reduced. All processors are connected to the CAN communication unit through the shared CANTX and CANRX buses, which reduces the required physical space and resources, and at the same time reduces the system complexity and cost, thereby solving the technical problems of the traditional multi-CAN transceiver solution occupying a large amount of physical space and resources, as well as high power consumption and cost, and achieving the technical effects of saving physical space and resources and reducing power consumption and cost.
[0030] The CAN communication unit T is the core part of the CAN bus interface, which is used to convert the data of the processor into a signal format suitable for transmission on the CAN bus, and is also responsible for receiving the data on the bus and converting it into a format that the processor can understand.
[0031] The TX port of the CAN communication unit T is directly connected to the CANTX bus for sending data; the RX port is connected to the CANRX bus through the diode D1 for receiving data. The diode D1 is used to prevent the reverse current on the bus from entering the CAN communication unit T and protect the circuit from damage.
[0032] The TX and RX ports of the processor are used to communicate with the CAN communication unit. The first target diodes (such as D2, D4, ……, D2n) are connected between the RX terminals of the processor (such as RX_1, RX_2, ……, RX_n) and the CANRX bus, ensuring that only forward signals can reach the processor and preventing errors caused by reverse signals. The second target diodes (such as D3, D5, ……, D2n + 1) are located between the TX terminals of the processor (such as TX_1, TX_2, ……, TX_n) and the CANTX bus, also playing a protective role to ensure that the data sent by the processor is not affected by other signals on the bus. The use of the target diodes (the first target diodes and the second target diodes) provides basic signal isolation, prevents the reverse propagation of the data stream, and protects the circuit components. In addition, the natural one-way conduction characteristic of the diodes ensures the correct data flow direction and avoids signal conflicts.
[0033] TX (Transmit) represents the port or function for transmitting signals. RX (Receive) represents the port or function for receiving signals. CANTX / CANRX respectively represent the transmit and receive signal lines on the CAN bus.
[0034] Diode D1, the first target diodes (such as D2, D4, ……, D2n) and the second target diodes (such as D3, D5, ……, D2n + 1) are all semiconductor devices with one-way conductivity, and are usually used to protect the circuit or control the current direction.
[0035] As an optional embodiment, it further includes a first resistor R1 and a second resistor R2; wherein, one end of the first resistor R1 is connected to the power supply, and the other end of the first resistor R1 is connected to the CANTX bus; one end of the second resistor R2 is connected to the power supply, and the other end of the second resistor R2 is connected to the CANRX bus.
[0036] One end of the first resistor R1 is connected to the power supply, and the other end is connected to the CANTX bus. When the CAN bus is idle, R1 helps maintain the voltage of the CANTX bus at a preset high level state, that is, a pull-up function. Similarly, one end of the second resistor R2 is connected to the power supply, and the other end is connected to the CANRX bus. It also keeps the CANRX bus at a preset high level state when the CAN bus is idle.
[0037] Both the first resistor R1 and the second resistor R2 are pull-up resistors, that is, resistors used to maintain the signal line at a high level when it is in an inactive state.
[0038] When no device is using the CAN bus for communication, the pull-up resistor ensures that the voltage of the bus remains at a stable high level, which helps to initialize the state of the receiver and avoid misjudgment caused by uncertain signal states. In some cases, especially for long-distance transmission or when there are multiple nodes on the bus, the pull-up resistor also plays a role in terminal matching, reducing signal reflection and improving signal integrity and communication reliability.
[0039] The above power supply refers to the power source in the circuit, which can be a battery, a regulated power supply, etc., and is used to provide the electrical energy required for the normal operation of the circuit.
[0040] As an alternative embodiment, the positive electrode of diode D1 is connected to the CANRX bus, and the negative electrode of diode D1 is connected to the RX terminal of CAN communication unit T.
[0041] The positive electrode of diode D1 is connected to the CANRX bus, and the negative electrode is connected to the RX terminal of CAN communication unit T. Such a connection method utilizes the unidirectional conductivity characteristic of the diode to ensure that the signal can only flow from the CANRX bus to CAN communication unit T and cannot flow in the reverse direction.
[0042] Diode D1 can effectively isolate the RX terminal of CAN communication unit T from the CANRX bus, preventing any noise or abnormal current that may flow backward from the bus from damaging the CAN communication unit. Since the diode blocks the reverse propagation of the signal, it can also help reduce the reflection problem that may occur when the signal propagates on the bus, thereby improving the signal integrity and communication quality.
[0043] A diode has two terminals, namely the positive electrode (anode) and the negative electrode (cathode). The current can only flow from the positive electrode to the negative electrode, which determines the unidirectional conductivity characteristic of the diode.
[0044] The CANRX bus is the receive signal line in the CAN bus system and is used to receive data signals from the bus to a local device (such as a microcontroller or a CAN communication module).
[0045] The RX terminal of CAN communication unit T is an input port of the CAN communication unit and is used to receive data signals from the CAN bus.
[0046] As an alternative embodiment, the positive electrode of the first target diode D2 is connected to the CANRX bus, the negative electrode of the first target diode (such as D2, D4,..., D2n) is connected to the negative electrode of the second target diode (such as D3, D5,..., D2n + 1), and the positive electrode of the second target diode (such as D3, D5,..., D2n + 1) is connected to the CANTX bus.
[0047] The first target diodes (such as D2, D4, ……, D2n), the anode of each diode is connected to the CANRX bus, and the cathode is connected to the cathode of the diode in the corresponding second target diode group; the second target diodes (such as D3, D5, ……, D2n+1), the anode of each diode is connected to the CANTX bus, and the cathode is connected to the cathode of the diode in the corresponding first target diode group. Among them, the signal can only flow from the CANRX bus through a series of diodes to the CANTX bus, but cannot flow in the reverse direction.
[0048] From the receiving bus (CANRX) to the transmitting bus (CANTX), it effectively prevents the reverse propagation of signals and reduces the risk of signal reflection and cross-interference. Diodes (the first target diodes and the second target diodes), as basic non-linear elements, can absorb transient voltages and currents, protect the subsequent circuits from overvoltage and reverse current, and enhance the robustness and reliability of the circuit.
[0049] The first target diodes (such as D2, D4, ……, D2n), the main function of these diodes is to receive signals from the CANRX bus and direct them to the subsequent circuits. The second target diodes (such as D3, D5, ……, D2n+1), the function of these diodes is to transfer the signals from the first target diode group to the CANTX bus and prevent the signals from flowing in the reverse direction at the same time.
[0050] Figure 2 Another schematic diagram of the CAN bus communication circuit provided by the embodiment of the present application, as Figure 2 shown, the CAN communication unit T includes at least two CAN transceivers; among them, the CANH terminal of the CAN transceiver is connected to the CANH bus, and the CANL terminal of the CAN transceiver is connected to the CANL bus.
[0051] At least two independent CAN transceivers are integrated in the CAN communication unit T, and each transceiver has its own CANH (High) and CANL (Low) ports, which are respectively connected to the CANH bus and the CANL bus.
[0052] Multiple CAN transceivers can process multiple data streams simultaneously, significantly improving the data processing capacity and communication efficiency of the system, and are suitable for applications with high bandwidth requirements. If one transceiver fails, the system can automatically switch to another transceiver to maintain the continuity of communication, greatly improving the reliability and fault tolerance of the system.
[0053] The CAN transceiver is the core component in the CAN bus communication system, which is used to convert the data of the processor into signals suitable for transmission on the CAN bus, and is also responsible for receiving and decoding the data from the bus.
[0054] CANH / CANL are two signal lines of the CAN bus. Among them, CANH (High) represents the high signal line, and CANL (Low) represents the low signal line. In CAN communication, data is encoded and transmitted through the voltage difference between these two signal lines.
[0055] As an alternative embodiment, the CAN communication unit T includes a first CAN transceiver T1, and the first CAN transceiver T1 is any one of at least two CAN transceivers; wherein, the TX terminal of the first CAN transceiver T1 is connected to the CANTX bus, and the RX terminal of the first CAN transceiver T1 is connected to the CANRX bus through a diode D1.
[0056] The TX terminal of the first CAN transceiver T1 is directly connected to the CANTX bus, which is used to send the data of the local device to the CAN bus; the RX terminal of T1 is connected to the CANRX bus through a diode D1, which is used to receive the data from the bus. The diode D1 plays a role of signal isolation and protection here.
[0057] As an alternative embodiment, the CAN communication unit T includes a second CAN transceiver T2, and the second CAN transceiver T2 is any one of at least two CAN transceivers other than the first CAN transceiver T1; wherein, the TX terminal of the second CAN transceiver T2 is used to connect the TX terminal of other devices (such as TX_n+1), and the RX terminal of the second CAN transceiver T2 is used to connect the RX terminal of other devices (such as RX_n+1).
[0058] The TX and RX terminals of the second CAN transceiver T2 are respectively connected to the TX_n+1 and RX_n+1 ports of other devices. T2 can not only establish a point-to-point communication link between the local device and a specific external device, but also act as a gateway or bridge to expand the scope and function of the communication network.
[0059] The first / second CAN transceiver (T1 / T2) is a key component in the CAN communication unit T, responsible for different communication tasks respectively. T1 is mainly used for interaction with the CAN bus, while T2 is used for direct communication with other specific devices.
[0060] The TX and RX port numbers "n+1" represent the communication ports of other devices connected to the second CAN transceiver T2, which is a dynamic or scalable connection method.
[0061] According to another aspect of the embodiments of the present application, a power electronic conversion device is provided. A complex programmable logic device and multiple processor units are arranged on the control board of the power electronic conversion device, and the complex programmable logic device includes a CAN bus communication circuit as described above.
[0062] As an alternative embodiment, the above-mentioned processor unit includes a digital signal processor or a microcontroller unit.
[0063] As an alternative embodiment, the above-mentioned power electronic conversion device includes a photovoltaic inverter or an energy storage converter.
[0064] Figure 3 Schematic diagram of the power electronic conversion device provided by the embodiment of the present application, as Figure 3 shown, the power electronic conversion device includes a complex programmable logic device (CPLD), two digital signal processors (DSP_1 and DSP_2), a microcontroller unit (MCU), and two CAN transceivers (transceiver 1 and transceiver 2).
[0065] Optionally, on the control board of the photovoltaic inverter or the energy storage converter, two digital signal processors (DSPs) and a programmable logic device (CPLD) are provided. Communication between these two DSPs and with other circuit boards of the inverter or converter (such as the human-machine interaction circuit board, arc strike detection board, PID board, etc.) is connected through CAN communication.
[0066] Communication can be connected between the two DSPs and with other circuit boards of the inverter (such as the human-machine interaction circuit board, arc strike detection board, anti-PID board, etc.) through CAN communication to achieve sharing, exchange, and control of data and information, etc.
[0067] Since the two DSPs are located on the same circuit board and the communication distance is relatively short, the CAN transceiver is omitted through circuit simplification, and the CPLD processes and realizes direct communication between devices. In addition to realizing direct CAN communication between several adjacent devices or processors through the communication connection of the CPLD, a connection port for the transceiver is reserved, and at the same time, the function of converting to a differential signal bus through the transceiver for communication with remote devices is realized. The above solutions are used to achieve the purposes of cost savings, circuit board space savings, and reliability improvement.
[0068] Furthermore, by using the logic processing ability of the CPLD, the two-way CAN transceiver signals on the control board are merged into one bus transceiver signal. Specifically, the CPLD performs a logical OR operation on the receiving end and the sending end of the two-way CAN transceiver signals respectively through the internal logic gate circuit, so as to merge the two-way signals or multiple signals into one way, enabling direct CAN communication between them.
[0069] Furthermore, through the CAN transceiver, the merged bus transceiver signal is converted into a differential bus signal. This CAN transceiver can convert the parallel bus transceiver signal into a differential CAN bus signal for CAN communication with other devices.
[0070] In the embodiments of the present application, it is possible to effectively save the physical space and resources on the control board, while also reducing the complexity and cost of the system. At the same time, this design can not only save CAN transceivers, but also reduce the power consumption of the photovoltaic inverter and improve its working efficiency.
[0071] In view of the characteristic that differential signals are conducive to long-distance transmission, the proximal device (the same circuit board or adjacent circuit boards with a short distance) is connected through the TX and RX signals, and the distal device (circuit boards or devices with a long distance, or in an environment with large interference) is connected through the differential CANH and CANL signals to achieve the optimization of the design.
[0072] The above circuit form can also implement related functions through discrete devices such as signal diodes and resistors (different from CPLD), and can also achieve CAN communication connection in a circuit without CPLD, thereby achieving the effect of saving transceivers.
[0073] Compared with the prior art, the beneficial effects of the technical solutions in the embodiments of the present application are as follows:
[0074] 1. Save resources: After being processed by CPLD logic and merged into a single bus for transceiver signals, the number of CAN transceivers and related components on the control board can be reduced, thus saving physical space and resources and alleviating the space and resource pressure on the control board.
[0075] 2. Reduce power consumption: Since the number of CAN transceivers is reduced, the corresponding power consumption will also be reduced, which is helpful for improving the energy utilization efficiency of the power consumption-sensitive photovoltaic inverter.
[0076] 3. Simplify the system: By merging multiple CAN transceiver signals into a single bus for transceiver signals, independent signal processing and conversion can be reduced, simplifying the system structure and reducing the complexity and cost of the system.
[0077] 4. Improve communication efficiency: By converting to differential bus signals through the CAN transceiver chip, communication delay can be reduced, the quality and efficiency of communication can be improved, and reliable transmission of data and information can be ensured.
[0078] 5. Enhance compatibility: Through CAN communication connection, data and information can be shared and exchanged with other circuit boards such as the human-machine interaction circuit board, arc strike detection board, and PID board, enhancing the compatibility and expandability of the system.
[0079] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper", etc. may be used herein to describe the spatial positional relationship of one device or feature to other devices or features as shown in the figures. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "beneath" the other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding explanations for the spatial relative descriptions used herein will be made accordingly.
[0080] In addition, it should be noted that the use of terms such as "first" and "second" to define components is only for the convenience of differentiating the corresponding components. Without further statement, the above terms have no special meaning, and thus should not be construed as limiting the protection scope of the present application.
[0081] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.
Claims
1. A CAN bus communication circuit, characterized in that: include: CAN communication unit; wherein the TX end of the CAN communication unit is connected to the CANTX bus, and the RX end of the CAN communication unit is connected to the CANRX bus through a diode; At least one communication port for connecting a processor unit, the communication port comprising a TX terminal and an RX terminal of the processor unit; wherein one end of a first target diode is respectively connected to the CANRX bus and the RX terminal of the processor unit, the other end of the first target diode is connected to a common end connected to one end of a second target diode and is connected to the TX terminal of the processor unit, and the other end of the second target diode is connected to the CANTX bus.
2. The CAN bus communication circuit according to claim 1, characterized in that: It also includes a first resistor and a second resistor; wherein one end of the first resistor is connected to a power supply, and the other end of the first resistor is connected to the CANTX bus; one end of the second resistor is connected to a power supply, and the other end of the second resistor is connected to the CANRX bus.
3. The CAN bus communication circuit according to claim 1, characterized in that: The anode of the diode is connected to the CANRX bus, and the cathode of the diode is connected to the RX terminal of the CAN communication unit.
4. The CAN bus communication circuit according to claim 1, characterized in that: An anode of the first target diode is connected to the CANRX bus, a cathode of the first target diode is connected to a cathode of the second target diode, and an anode of the second target diode is connected to the CANTX bus.
5. The CAN bus communication circuit according to claim 1, characterized in that: The CAN communication unit includes at least two CAN transceivers; wherein the CANH end of the CAN transceiver is connected to the CANH bus, and the CANL end of the CAN transceiver is connected to the CANL bus.
6. The CAN bus communication circuit according to claim 5, characterized in that: The CAN communication unit includes a first CAN transceiver, which is any one of at least two CAN transceivers; wherein the TX end of the first CAN transceiver is connected to a CANTX bus, and the RX end of the first CAN transceiver is connected to a CANRX bus via a diode.
7. The CAN bus communication circuit according to claim 6, characterized in that: The CAN communication unit includes a second CAN transceiver, which is any one of at least two CAN transceivers except the first CAN transceiver; wherein the TX end of the second CAN transceiver is used to connect to the TX end of other devices, and the RX end of the second CAN transceiver is used to connect to the RX end of other devices.
8. A power electronic conversion device, characterized in that: A complex programmable logic device and a plurality of processor units are arranged on a control board of the power electronic conversion device, and the complex programmable logic device includes a CAN bus communication circuit as claimed in any one of claims 1 to 7.
9. The power electronic conversion device according to claim 8, characterized in that: The processor unit comprises a digital signal processor or a microcontroller unit.
10. The power electronic conversion device according to claim 8, characterized in that: The power electronic conversion device includes a photovoltaic inverter or an energy storage converter.