CAN bus-based smart electric vehicle charger

Abstract

This smart electric vehicle charger, based on the CAN bus and compatible with multiple charging plugs, is provided via CAN bus communication through CP / PP terminals. [Solution] The smart electric vehicle charger comprises a charger body. The charger body includes an MCU and power input terminals and charging interface terminals connected to the MCU, respectively. The charging interface terminals have a charging power terminal and a CP / PP terminal. A CAN transceiver chip for communication with the vehicle based on the CAN bus is additionally installed corresponding to the CP / PP terminal, and the CAN transceiver chip is connected to the MCU. In the first operating state, the CP / PP terminal functions as a channel for CAN signal transmission and establishes a CAN bus communication connection with a vehicle that supports advanced communication. In the second operating state, the CP / PP terminal maintains the conventional CP / PP control mode and connects with a vehicle that does not support advanced communication. This allows CAN bus communication to be achieved using the CP / PP terminal without requiring additional physical connections, reducing the complexity of the system configuration, enabling automatic switching, and improving the level of intelligence.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle chargers, and particularly to a smart electric vehicle charger based on a CAN bus that supports multiple charging plugs (such as CCS1&2, CCS Type1&2, etc.) through CAN bus communication via CP / PP terminals.

Background Art

[0002] As the global interest in environmental protection and energy efficiency continues to grow, the popularity of electric vehicles (EVs) has been rapidly increasing. To meet the requirements of different regions and vehicle manufacturers, the charging interface standards for electric vehicles also exhibit diverse characteristics. Currently, commonly used charging standards include CCS1&2, CCS Type1&2h, etc.

[0003] However, existing AC charging stations typically support only a single charging standard and have the following problems in terms of communication functions. First, it is the functional limitation of the CP / PP terminals. Conventional CP (Control Pilot) and PP (Proximity Pilot) pins are mainly used for simple charging control and status display, and their potential capabilities have not been fully utilized. Second, the lack of integrated CAN bus communication. Existing charging stations usually achieve communication with the vehicle ECU through the vehicle's diagnostic interface (such as OBD-II), and such a method increases the complexity and cost of the system. Furthermore, there is a lack of intelligence. Advanced charging control and battery status monitoring cannot be achieved through the CP / PP terminals.

[0004] Within the industry, there are a few technical solutions that support multiple charging standards, such as Patent Document 1. The "Electric Vehicle Charging System Based on European Standard Charging Stations" disclosed in Patent Document 1 includes a charging socket interface, an electric vehicle communication controller, an onboard charger, and a power battery component. The charging socket interface includes a DC charging port and an AC charging port, the AC charging port including an AC input terminal and a control terminal. The power battery component includes a battery management system and a power battery pack, the power battery pack being connected to the DC charging port. The electric vehicle communication controller includes a first control terminal, a second control terminal, and a third control terminal. The first control terminal is connected to the control terminal, the second control terminal is connected to the onboard charger, and the third control terminal is connected to the battery management system via a fast-charging CAN. The onboard charger includes a power input terminal and a power output terminal, the power input terminal is connected to the AC input terminal, and the power output terminal is connected to the battery management system. The charging system conforms to European standard charging stations and activates the onboard charger via CC lines, PE lines, and CP OUT, and then determines the charging type of the electric vehicle based on its PWM signal. In no event shall the CC line, PE line, or CP line carry the CAN signal.

[0005] Furthermore, Patent Document 2 discloses an "integrated AC / DC electric vehicle charging system and its control method," which includes a charging socket, an on-board charger, a power distribution control module, a BMS module, and a battery pack. The charging socket is equipped with an EVCC control module, and the EVCC control module integrates a communication control chip for the electric vehicle. When a DC charging gun is connected, the EVCC control module performs DC communication and control with the BMS module via the power distribution control module, thereby causing the DC charging gun to perform DC charging. When an AC charging gun is connected, AC communication and control are performed via the on-board charger, controlling the on-board charger to convert AC power to DC power and perform AC charging. In this technology, the vehicle's charging socket receives a signal from the charging gun, converts it to a CAN signal, and performs communication and control with the electric vehicle; in other words, the vehicle's charging socket functions as a converter between CP / PP signals and CAN signals. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Chinese Patent No. CN115320446A Specification [Patent Document 2] Chinese Patent No. CN116691385A Specification [Overview of the project] [Problems that the invention aims to solve]

[0007] The aforementioned prior art charging systems all suffer from relatively complex charging strategies and have room for improvement in terms of intelligence. Therefore, the applicant continued research on a smart AC charging stand that can simultaneously support multiple charging standards and implement CAN bus communication via CP / PP terminals.

[0008] In view of the above circumstances, the present invention aims to provide a smart electric vehicle charger based on the CAN bus that overcomes the shortcomings of the prior art by realizing CAN bus communication using CP / PP terminals, eliminating the need for additional physical connections, reducing system complexity, enabling automatic switching, and improving the level of intelligence. [Means for solving the problem]

[0009] To achieve the above objective, the smart electric vehicle charger based on the CAN bus of this invention employs a technical means comprising an electric vehicle charger body. The electric vehicle charger body includes an MCU and power input terminals and charging interface terminals connected to the MCU, respectively. The charging interface terminals have a charging power terminal and a CP / PP terminal. A CAN transceiver chip is additionally installed corresponding to the CP / PP terminal, and the CAN transceiver chip is configured to communicate with the electric vehicle based on the CAN bus and is connected to the MCU.

[0010] In the first operating state, the CP / PP terminal functions as a channel for CAN signal transmission, establishing a CAN bus communication connection with vehicles that support advanced communication.

[0011] In the second operating state, the CP / PP terminal maintains the conventional CP / PP control mode and connects to vehicles that do not support advanced communication.

[0012] This invention offers significant advantages and beneficial effects compared to the prior art. Specifically, as is clear from the above technical configuration, this invention mainly involves adding a CAN transceiver chip to the CP / PP terminal, and the CAN transceiver chip is configured to enable communication with the vehicle based on the CAN bus. The CAN transceiver chip is also connected to the MCU. In the first operating state, the CP / PP terminal is used as a channel for CAN signal transmission, establishing a CAN bus communication connection with a vehicle that supports advanced communication. In the second operating state, the CP / PP terminal maintains the conventional CP / PP control mode and connects with a vehicle that does not support advanced communication. This allows CAN bus communication to be achieved using the CP / PP terminal without requiring additional physical connections, reducing system complexity and improving the level of intelligence through automatic switching.

[0013] Furthermore, the aforementioned structural design allows the charging device to function as a boundary node in an energy management system, improving the overall system's scalability and compatibility.

[0014] In order to more clearly explain the structural features and effects of this invention, the invention will be described in detail below with reference to the attached drawings and specific embodiments. [Brief explanation of the drawing]

[0015] [Figure 1] This figure shows the structure of a smart electric vehicle charger based on a CAN bus according to one embodiment of the present invention. [Figure 2] This figure shows a structure in which a smart electric vehicle charger based on a CAN bus, according to one embodiment of the present invention, is connected to a charging plug with an extension cable. [Figure 3] This is a structural diagram of a CAN bus-based smart electric vehicle charger according to another embodiment of the present invention. [Figure 4]This is a schematic diagram of a CAN bus communication module based on CP / PP terminals between a smart electric vehicle charger and an electric vehicle according to one embodiment of the present invention. [Figure 5] This is a flowchart (showing an automatic switching charging method) of an automatic switching mechanism when a smart electric vehicle charger according to one embodiment of the present invention charges an electric vehicle. [Figure 6] This is a schematic diagram illustrating the communication between a smart electric vehicle charger, according to one embodiment of the present invention, and multiple systems of an electric vehicle. [Modes for carrying out the invention]

[0016] Figures 1 to 6 show specific structures according to embodiments of the present invention.

[0017] This invention relates to a smart electric vehicle charger (referring to a smart electric vehicle AC charging station) based on a CAN bus. The smart electric vehicle charger based on a CAN bus includes a charger body, which comprises an MCU and power input terminals and charging interface terminals connected to the MCU, respectively. Specifically, as shown in Figure 1, the charger body is further provided with a power module, a wired or wireless communication module, a communication port, and a real-time clock. The power module is connected between the power input terminal and the charging interface terminal, and the power module, real-time clock, and wired or wireless communication module are each connected to the MCU. The other end of the wired or wireless communication module is connected to the communication port. The communication port is used to share data information acquired via the CAN bus with an external EMS or cloud service. In this embodiment, it can be understood more specifically that a protocol conversion module is provided for sharing vehicle information acquired by CAN communication with an external EMS or cloud service via an OCPP protocol stack. The charging interface end includes a charging power terminal and a CP / PP terminal, and a charging plug with an extension cable is detachably or integrally connected to the charging interface end. Here, the charging power terminal and the CP / PP terminal are essential terminals for a general electric vehicle charger.

[0018] The CP / PP terminal includes a CP terminal and a PP terminal. In the relevant standards regarding the charging of new energy vehicles, the CP terminal and the PP terminal have specific meanings. In the AC normal charging plug of the European standard CCS, the CP terminal is a control pilot terminal, and the PP terminal is a plug detection terminal. The charging power terminal includes an L terminal, an N terminal, and a PE terminal. The L terminal is connected to the phase wire of the power supply and is the main current path. The N terminal is connected to the neutral wire and provides a reference potential as the path for the current to return to the power supply. The PE terminal is a protective ground wire, which provides a safe grounding path by connecting the device housing to the ground and prevents electric shock.

[0019] For the CP / PP terminal, a CAN transceiver IC is additionally installed and configured to communicate based on the CAN bus with the electric vehicle. The CAN transceiver chip is connected to the MCU. The charger body has an automatic switching mechanism. When it is detected that the connected vehicle supports high-level communication, the CP / PP terminal becomes a channel for CAN signal transmission to establish a CAN bus communication connection with the high-level communication-compatible vehicle (that is, the charging between the charging system and the electric vehicle is directly performed by CAN communication). On the other hand, when it is detected that the vehicle does not support high-level communication, the conventional CP / PP control mode is maintained. Also, it can be understood as follows. In the first usage state, the CP / PP terminal becomes a channel for CAN signal transmission to establish a CAN bus communication connection with the high-level communication-compatible vehicle. In the second usage state, the CP / PP terminal maintains the conventional CP / PP control mode to correspond to vehicles that do not support high-level communication. This method can be compatible with multiple charging standard interfaces (including but not limited to CCS1&2, CCS Type1&2, etc.).

[0020] The automatic switching mechanism can employ methods such as a handshake protocol, voltage detection, or signal detection. In actual design, one or more of these methods can be combined and configured. Specifically, these are as follows:

[0021] In Method 1, a detection module is added to the CP / PP terminal and configured to detect whether the vehicle supports advanced communication. The detection module is connected to the MCU, and if the detection module detects that the vehicle supports advanced communication, the CP / PP terminal becomes a channel for CAN signal transmission and a CAN bus communication connection is established (i.e., charging of the electric vehicle and the charging system are performed directly via CAN communication). On the other hand, if it is detected that the vehicle does not support advanced communication, the conventional CP / PP control mode is maintained. The detection module includes a voltage detection circuit. The voltage detection circuit is configured to determine whether the vehicle supports advanced communication by measuring the voltage change at the CP / PP terminal. Alternatively, the detection module includes a signal analysis unit. The signal analysis unit is configured to analyze the signal characteristics (e.g., frequency and waveform) of the CP / PP terminal. As shown in Figure 1, one end of the detection module is connected to the CP / PP terminal and the other end is connected to a switching control circuit (the structure within the dashed box in Figure 1 is a simplified representation of the switching control circuit). The MCU has a conventional CP / PP signal connection terminal and a CAN communication connection terminal (the CAN communication connection terminal is connected to the CAN communication module). The switching control circuit switches the CP / PP terminal to either the conventional CP / PP signal connection terminal or the CAN communication connection terminal depending on the detection result of the detection module.

[0022] In Method 2, the automatic switching mechanism defines a specific CAN message frame to confirm the communication capabilities of both parties. For example, by performing CAN bus communication using the ISO15764 and KWP2000 protocols and sending a specific diagnostic message frame at the handshake phase, the communication capabilities of both parties are confirmed, and the functional mode of the CP / PP terminal is dynamically adjusted based on the detection result. In either Method 1 or Method 2, the automatic switching mechanism achieves functional switching by adjusting the hardware configuration or software protocol stack based on the detection result (specifically, the detection result by the detection module or the confirmation result by the handshake protocol).

[0023] This charger can connect not only to electric vehicles but also to other energy nodes such as portable batteries or stationary battery storage systems. These energy nodes are connected to the charger via interfaces used for power transmission and CAN communication, enabling mutual communication of energy and status information under a unified data model.

[0024] Referring to Figures 1 and 3, the CAN bus is a serial communication protocol widely used in the control field of the automotive industry and other applications. It is used for communication between automotive electronic systems and possesses high reliability, excellent noise immunity, and good real-time capabilities. In a CAN communication system, the CAN communication module is an important component. The CAN communication module includes a CAN controller and a CAN transceiver chip. The CAN controller is usually integrated into a processor, microcontroller, or embedded system, but there are also standalone CAN controllers that independently transmit and receive CAN bus data. Therefore, in this invention, if the MCU integrates a CAN controller, the CAN transceiver chip is connected to the CAN controller. On the other hand, if the MCU does not integrate a CAN controller, a CAN communication module is additionally installed to the CP / PP terminals. The CAN communication module includes an interconnected CAN controller and a CAN transceiver chip, and the CAN controller is connected to the MCU.

[0025] Next, with reference to Figures 1 and 5, an automatic switching charging method for charging a vehicle using the CAN bus-based smart electric vehicle charger described above will be explained. This method includes the following steps.

[0026] In step 1, connect the charging interface terminal to the vehicle. In Step 2, when the user connects the vehicle to the smart electric vehicle charger, the smart electric vehicle charger immediately detects the vehicle's communication capabilities. Specifically, it uses voltage changes at the CP / PP terminals, specific signal characteristics (e.g., frequency and waveform), or a handshake signal to determine whether the vehicle supports CAN communication. In other words, it detects whether the vehicle's communication capabilities support advanced communication (CAN communication) and automatically selects a communication mode based on the detection result.

[0027] If the vehicle's communication capabilities support advanced communication, the CP / PP terminal becomes a channel for CAN signal transmission, establishing a CAN bus communication connection with the vehicle. This CAN bus communication connects to the vehicle's internal network system, thus establishing a CAN network (see Figure 6). When the smart electric vehicle charger is connected to the vehicle and CAN communication is activated, the smart electric vehicle charger acquires the vehicle's battery parameters (e.g., capacity, charging current, etc.) and notifies the vehicle of its own parameters (e.g., charger capacity, etc.), and then begins charging the vehicle (electric vehicle). In this process, the conventional CP / PP function is replaced by CAN communication, battery status parameters are acquired in real time, smart charging control is performed, and safety and efficiency during the charging process are ensured. During the charging process, the charging status is continuously monitored between the smart electric vehicle charger and the vehicle via CAN communication, and parameters such as charging current are controlled. This enables battery status monitoring (e.g., reading battery SOC, SOH, and other parameters), fault diagnosis (e.g., obtaining vehicle fault codes and detailed information using diagnostic protocols such as UDS / KWP2000), and advanced charging control (e.g., working in conjunction with the vehicle's ECU to realize smart charging modes such as constant current / constant voltage charging), and disconnects the connection after charging is complete. In this embodiment, data information acquired via the CAN bus is shared with an external EMS or cloud service via the OCPP protocol stack.

[0028] On the other hand, if the vehicle's communication capabilities do not support advanced communication, the CP / PP terminal will maintain the conventional CP / PP control mode, start charging the vehicle (electric vehicle), and disconnect after charging is complete.

[0029] During the charging process in CAN communication mode (i.e., CP / PP-based CAN mode), the smart electric vehicle charger is in a state of bidirectional communication with the vehicle's ECU and other systems via the CAN bus interface, and therefore can perform the following functions: (1) Battery health assessment. The health of the battery is assessed and its lifespan is predicted through long-term monitoring of battery condition parameters. (2) Anomaly detection. The system monitors abnormalities during the charging process (overvoltage, undervoltage, overcurrent, etc.) in real time, reads the vehicle's fault code, and transmits warning information via the CAN bus. It also combines feedback information from the vehicle's ECU to adjust the charging mode and ensure safe and efficient charging. (3) Energy management. It communicates with the vehicle's energy management system via CAN bus communication and dynamically adjusts its operation in coordination with the system. Based on battery information acquired via CAN communication, it optimizes the charging strategy and improves energy utilization efficiency. (4) Information acquired via the CAN bus can be uploaded to a cloud server via a wired or wireless communication module. Specifically, data information is shared with an external EMS or cloud service via the OCPP protocol stack, enabling local or remote cloud monitoring and management (at least battery status monitoring, fault diagnosis, charging strategy optimization, V2H control, etc.).

[0030] The smart electric vehicle charger supports multiple charging plugs (CCS1&2, CCS Type1&2, etc.) and enables advanced communication with electric vehicles via CP / PP terminals. Specifically, this invention has the following advantages. (1) Supports multiple standards. It supports multiple charging interface standards such as CCS1&2 and CCS Type1&2, meeting the needs of different vehicle models and markets. The adapter, which supports multiple charging plug standards, can automatically adapt to the needs of each vehicle through an electrical interface switching circuit. (2) It has backward compatibility. It implements CAN functionality based on CP / PP in each standard, while maintaining the conventional CP / PP functionality. Therefore, even if the vehicle to be charged (electric vehicle) does not support CAN, it can be charged using the conventional CP / PP functionality. (3) Integrated CAN bus. CAN bus communication is achieved using CP / PP terminals, eliminating the need for additional physical connections and reducing system complexity. Compared to conventional electric vehicle chargers, this invention adds a CAN transmit / receive transceiver chip to the hardware design, enabling bidirectional communication with the vehicle's ECU, thus eliminating the need for additional hardware adapters. Regarding software protocols, compatibility is ensured by adopting standard automotive CAN protocols (ISO15764, KWP2000) and diagnostic protocols (UDS). (4) It has an automatic switching mechanism. When the smart electric vehicle charger is connected to an electric vehicle, it can automatically switch between the CP / PP control function and the CAN communication function according to the vehicle's requirements. When connecting to an electric vehicle, the charger checks whether the electric vehicle supports CP / PP-based CAN functions using methods such as voltage detection, signal analysis, and handshake protocols, and decides whether to switch to the CAN communication function. If it switches to CP / PP-based CAN functions, the conventional CP / PP function is replaced by CAN communication, and the smart electric vehicle charger communicates with the electric vehicle via the CAN bus to realize advanced charging functions. (5) Perform smart diagnostics and control. By communicating with the vehicle's ECU (engine) and other systems (instrument panel assembly, air conditioning heating system, anti-lock braking system, passive safety devices, vehicle control module, etc.) via the CAN bus interface, it enables battery status monitoring, fault diagnosis, advanced charging control, etc. (6) Data sharing and remote cloud monitoring and management. Data information acquired via the CAN bus is shared with external EMS or cloud services via the OCPP protocol stack, enabling monitoring and management locally or remotely in the cloud (including at least battery status monitoring, fault diagnosis, charging strategy optimization, V2H control, etc.).

[0031] As described above, the CAN bus-based smart electric vehicle charger of this invention, with its multi-standard compatibility and advanced communication capabilities, can significantly improve the charging experience and battery management capabilities. This technology not only reduces system complexity but also provides a foundation for future intelligent electric vehicle charging, cloud-based charging services, energy management, and vehicle maintenance.

Claims

1. A smart electric vehicle charger based on a CAN bus, which includes an electric vehicle charger unit, The electric vehicle charger body includes an MCU and a power input terminal and a charging interface terminal connected to the MCU, respectively. The aforementioned charging interface terminal has a charging power terminal and a CP / PP terminal. A CAN transceiver chip for communication with an electric vehicle based on a CAN bus is additionally installed in accordance with the CP / PP terminal, and the CAN transceiver chip is connected to the MCU. In the first operating state, the CP / PP terminal is used as a channel for CAN signal transmission, establishing a CAN bus communication connection with a vehicle that supports advanced communication. In a second operating state, the CP / PP terminal maintains the conventional CP / PP control mode and connects to a vehicle that does not support advanced communication, characterized by a CAN bus-based smart electric vehicle charger.

2. A detection module is additionally installed on the aforementioned CP / PP terminal, which is used to detect whether or not the vehicle supports advanced communication. The smart electric vehicle charger based on a CAN bus according to claim 1, characterized in that the detection module is connected to the MCU, and when the detection module detects that the vehicle supports advanced communication, the CP / PP terminal becomes a channel for CAN signal transmission and establishes a CAN bus communication connection, and when the detection module detects that the vehicle does not support advanced communication, the conventional CP / PP control mode is maintained.

3. The smart electric vehicle charger based on a CAN bus according to claim 2, wherein the detection module includes a voltage detection circuit, which is used to measure the voltage change of the CP / PP terminals and to determine whether or not the vehicle supports advanced communication.

4. The CAN bus-based smart electric vehicle charger according to claim 2, characterized in that the detection module includes a signal analysis unit used to analyze the signal characteristics of the CP / PP terminals.

5. The smart electric vehicle charger based on a CAN bus according to claim 2, characterized in that one end of the detection module is connected to the CP / PP terminal and the other end is connected to a switching control circuit, the MCU has a conventional CP / PP signal connection terminal and a CAN communication connection terminal, and the switching control circuit switches and connects the CP / PP terminal to either the conventional CP / PP signal connection terminal or the CAN communication connection terminal based on the detection result of the detection module.

6. The charger body is further provided with a power module, a wired or wireless communication module, and a communication port, the power module is connected between the power input terminal and the charging interface terminal, the power module and the wired or wireless communication module are each connected to the MCU, and the other end of the wired or wireless communication module is connected to the communication port, characterized in that the smart electric vehicle charger based on a CAN bus according to claim 1.

7. The smart electric vehicle charger based on a CAN bus according to claim 1, characterized in that the charger body is further provided with a real-time clock, and the real-time clock is connected to the MCU.

8. The CAN bus-based smart electric vehicle charger according to claim 1, characterized in that the CP / PP terminal includes a CP terminal and a PP terminal, and the charging power terminal includes an L terminal, an N terminal, and a PE terminal.

9. The smart electric vehicle charger based on a CAN bus according to claim 1, characterized in that the MCU integrates a CAN controller and the CAN transceiver chip is connected to the CAN controller, or, if the MCU does not integrate a CAN controller, a CAN communication module is additionally installed corresponding to the CP / PP terminals, the CAN communication module includes interconnected CAN controllers and the CAN transceiver chip, and the CAN controller is connected to the MCU.

10. The CAN bus-based smart electric vehicle charger according to claim 1 is characterized in that the charging interface terminal is detachably or integrally connected to a charging plug with an extension cable.

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