Overcurrent protection method and system for charging pile

Abstract

The application provides a method and system for overcurrent protection of a charging pile. The charging pile controller compares the upper limit current required by a vehicle with the maximum current upper limit of the charging pile, and takes the smaller one as a reference to calculate the overcurrent protection threshold. In this way, the threshold is neither too high to effectively protect the vehicle nor too low to limit the charging power. At the same time, the intelligent circuit breaker directly monitors the actual charging current and autonomously executes tripping, without relying on controller software processing and communication links, so that the response speed is faster and the reliability is higher. After being disconnected, the state is actively reported to ensure that the charging pile controller stops power output in time, forming a closed loop of hardware protection and system control.

Description

[0001] This case is a divisional application based on the invention patent filed on August 30, 2023, with application number 202311107379.1 and title "A Method for Intelligent Overcurrent Protection and a Charging Pile". Technical Field

[0002] This invention relates to the field of overcurrent protection technology, and in particular to overcurrent protection methods and systems for charging piles. Background Technology

[0003] With the development of electric vehicles, various models and types of vehicles exist, each with different charging current and voltage requirements. Different electric vehicle models select their protection devices (fuses) based on the battery capacity or the current required by the charging circuit. However, the selection of fuses for the main circuit of charging piles is based on the principle of compatibility with high current, which cannot consider matching with the fuses of electric vehicles. There is a difference in overcurrent or short-circuit protection time between the two; the lower the current rating of the device, the faster the fuse will blow. This can cause the main circuit protection devices of electric vehicles charging with low current to be prioritized for protection, potentially damaging the devices.

[0004] Therefore, how to protect devices such as fuses in the electric vehicle charging circuit from damage and reduce the need for replacement of such devices when charging pile failures cause overcurrent or short circuits has become an urgent problem to be solved. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an overcurrent protection method and system for charging piles, which can provide overcurrent protection for electric vehicles through charging piles.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: An overcurrent protection method for a charging pile includes: The charging pile controller receives messages between the electric vehicle's battery management system and the charging pile, and collects the electric vehicle's maximum current requirement. The charging pile controller determines whether the upper limit current demand is greater than the upper limit current of the charging pile. If so, it calculates the overcurrent protection threshold based on the upper limit current. Otherwise, it calculates the overcurrent protection threshold based on the upper limit current demand and sets the overcurrent protection threshold for the smart circuit breaker. The intelligent circuit breaker monitors the charging current. If the charging current exceeds the overcurrent protection threshold, the intelligent circuit breaker will actively disconnect and report the status to the charging pile controller.

[0007] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is as follows: An overcurrent protection system for a charging pile, comprising the steps of implementing the aforementioned overcurrent protection method for a charging pile, including: A charging pile includes a charging pile controller, a charging gun and a smart circuit breaker that are communicatively connected to the charging pile controller, and one end of the smart circuit breaker is electrically connected to the charging gun. An electric vehicle, connected to the charging gun, includes a battery and a battery management system, wherein the battery management system is communicatively connected to the charging pile controller.

[0008] The beneficial effects of this invention are as follows: By comparing the upper limit of the vehicle's required current with the upper limit of the charging pile's maximum current, the smaller of the two is used as the benchmark to calculate the overcurrent protection threshold. This avoids both an excessively high threshold that fails to effectively protect the vehicle and an excessively low threshold that limits charging power. Simultaneously, the intelligent circuit breaker directly monitors the actual charging current and autonomously trips, without relying on controller software processing and communication, resulting in faster response and higher reliability. After disconnection, it actively reports its status, ensuring that the charging pile controller promptly stops power output, forming a closed loop of hardware protection and system control. Attached Figure Description

[0009] Figure 1 This is a flowchart of an intelligent overcurrent protection method according to an embodiment of the present invention; Figure 2 This is a structural example diagram of a charging pile with intelligent overcurrent protection according to an embodiment of the present invention. Detailed Implementation

[0010] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0011] Please refer to Figure 1 A method for intelligent overcurrent protection includes the following steps: S1. When the charging gun is detected to be connected to the electric vehicle, the charging information of the electric vehicle, including the upper limit current demand and the current demand, is obtained. S2. Based on the required upper limit current and the maximum current limit of the charging pile, set the overcurrent protection threshold for the smart circuit breaker and enter the charging pile charging start process. S3. In conjunction with the intelligent circuit breaker, based on the required current and the overcurrent protection threshold, overcurrent protection is provided for the charging of the electric vehicle. The intelligent circuit breaker is located between the charging gun and the power module that supplies power to the charging gun.

[0012] As can be seen from the above description, the beneficial effects of the present invention are as follows: The present invention provides an intelligent overcurrent protection method and charging pile, in which an intelligent circuit breaker is installed inside the charging pile, and the overcurrent protection threshold of the intelligent circuit breaker is set according to the charging specifications of the electric vehicle. At the same time, combined with the demand current of the electric vehicle, the overcurrent protection is adapted to the charging process of electric vehicles of different specifications, which greatly avoids the replacement and maintenance of electric vehicle charging circuit devices caused by overcurrent due to short circuit faults in the charging pile.

[0013] Furthermore, the determination of the overcurrent protection threshold is specifically as follows: Determine whether the upper limit current of the demand is greater than the upper limit current of the charging pile. If so, use a preset first multiple of the upper limit current of the charging pile as the overcurrent protection threshold; otherwise, use a preset second multiple of the upper limit current of the demand as the overcurrent protection threshold.

[0014] As described above, by comparing the maximum current limit of the charging pile with the maximum current requirement of the electric vehicle, the value of the overcurrent protection threshold is determined, ensuring that effective overcurrent protection can be formed by the value of the overcurrent protection threshold.

[0015] Further, step S3 includes the following steps: According to the required current, a current control command is sent to the power module, and the charging current is monitored in real time. If the current is greater than the required current but does not reach the overcurrent protection threshold, an active disconnection command is sent to the smart circuit breaker.

[0016] As described above, the current is controlled according to the required current. When the current exceeds the required current, the power module may malfunction. Even if the overcurrent protection threshold is not reached, the intelligent circuit breaker can still be controlled to actively disconnect to perform priority overcurrent protection when the circuit breaker does not react.

[0017] Further, step S3 includes the following steps: The system receives overcurrent information reported by the intelligent circuit breaker and sends a command to the power module to stop supplying power. The overcurrent information is monitored in real time by the intelligent circuit breaker. When the overcurrent protection threshold is detected, the circuit breaker will actively disconnect and report the overcurrent information.

[0018] As described above, the intelligent circuit breaker also monitors the charging current in real time. If the current exceeds the overcurrent protection threshold, it will actively disconnect and report the overcurrent, and the charging pile controller will control the power module to stop supplying power.

[0019] Furthermore, step S2 also includes the following steps: S21. Set the operating time for overcurrent protection: vehicle fuse blowing time > overcurrent protection operating time > short circuit protection time.

[0020] As described above, the overcurrent protection action time is also set to adapt to the protection of electric vehicles of different specifications during the charging process.

[0021] Please refer to Figure 2 A charging pile with intelligent overcurrent protection includes a power module, an intelligent circuit breaker, a charging pile controller, and a charging gun. One end of the intelligent circuit breaker is electrically connected to the charging gun, and the other end is electrically connected to the power module; The charging pile controller is communicatively connected to the power module and the intelligent circuit breaker, and implements the steps in the intelligent overcurrent protection method described above.

[0022] As can be seen from the above description, the beneficial effects of the present invention are as follows: The present invention provides an intelligent overcurrent protection method and charging pile, in which an intelligent circuit breaker is installed inside the charging pile, and the overcurrent protection threshold of the intelligent circuit breaker is set according to the charging specifications of the electric vehicle. At the same time, combined with the demand current of the electric vehicle, the overcurrent protection is adapted to the charging process of electric vehicles of different specifications, which greatly avoids the replacement and maintenance of electric vehicle charging circuit devices caused by overcurrent due to short circuit faults in the charging pile.

[0023] Furthermore, the power module includes a power module controller and a DC-DC power module; The charging pile controller is communicatively connected to the power module controller, and the power module controller is communicatively connected to the DC-DC power module.

[0024] As described above, the power module specifically includes a power module controller and a DC-DC power module. The charging pile controller controls the output of the DC-DC power module by issuing commands to the power module controller.

[0025] Furthermore, the charging pile controller communicates with the power module controller via LAN, and the power module controller communicates with the DC-DC power module via CAN.

[0026] As described above, the communication between the charging pile controller, the power module controller, and the DC-DC power module is as shown above, which is a specific embodiment of the present invention.

[0027] Furthermore, a DC meter is connected between the intelligent circuit breaker and the charging gun, and the charging pile controller is connected to the DC meter.

[0028] As described above, the charging pile controller obtains charging current information by connecting a DC meter between the smart circuit breaker and the charging gun.

[0029] Furthermore, the charging pile controller communicates with the smart circuit breaker and with the DC meter via RS485, and the charging pile controller communicates with the electric vehicle via CAN through the charging gun.

[0030] As described above, the communication methods between the charging pile controller and the smart circuit breaker, and between the charging pile controller and the DC meter, are as shown above, which is a specific embodiment of the present invention.

[0031] The present invention relates to an intelligent overcurrent protection method and a charging pile, which is applicable to scenarios where the charging pile needs to be adapted to charge different models of electric vehicles, such as charging piles in charging stations.

[0032] Please refer to Figure 1 Embodiment 1 of the present invention is as follows: A method for intelligent overcurrent protection includes the following steps: S1. When a connection is established between the charging gun and the electric vehicle, the charging information of the electric vehicle, including the upper limit current demand and the current demand, is obtained.

[0033] In this embodiment, after the charging gun establishes a connection with the electric vehicle, the charging pile controller receives information from the electric vehicle via CAN communication, including the required upper limit current, SOC, upper limit voltage, and required current. Among these: Maximum current demand: This is the maximum current that may be required during the entire charging process of an electric vehicle.

[0034] Required current: This is the real-time current when the electric vehicle is charging. It is not allowed to exceed this current during charging. The charging module can be controlled by the charging pile controller to ensure that the charging does not exceed this current.

[0035] S2. Based on the required upper limit current and the maximum current limit of the charging pile, set the overcurrent protection threshold for the smart circuit breaker and enter the charging pile charging start process. The overcurrent protection threshold is determined as follows: Determine whether the upper limit current of the demand is greater than the upper limit current of the charging pile. If so, use a preset first multiple of the upper limit current of the charging pile as the overcurrent protection threshold; otherwise, use a preset second multiple of the upper limit current of the demand as the overcurrent protection threshold.

[0036] In this embodiment, both the first preset multiple and the second preset multiple are 1.2 times. In other equivalent embodiments, they can be set according to actual needs.

[0037] Based on the collected electric vehicle information, the charging pile controller determines whether the upper limit current demand exceeds the maximum current limit of the charging pile. If it does, 1.2 times the maximum current of the charging pile is used as the overcurrent protection value; otherwise, 1.2 times the upper limit current demand of the electric vehicle is used as the overcurrent protection value. The intelligent circuit breaker is configured via RS485 communication as the overcurrent protection threshold for this charging process.

[0038] Step S2 also includes the following steps: S21. Set the operating time for overcurrent protection: vehicle fuse blowing time > overcurrent protection operating time > short circuit protection time.

[0039] The charging pile controller can be configured via RS485 to set the overcurrent protection action time, which can be set according to actual conditions, for example, from 1 to 5ms. The vehicle fuse blowing time > the overcurrent protection action time > the short circuit protection time; the vehicle fuse blowing time is generally more than 10ms.

[0040] After the charging pile controller completes the overcurrent protection threshold setting, it enters the normal charging pile startup process.

[0041] S3. In conjunction with the intelligent circuit breaker, based on the required current and the overcurrent protection threshold, overcurrent protection is provided for the charging of the electric vehicle. The intelligent circuit breaker is located between the charging gun and the power module that supplies power to the charging gun.

[0042] Step S3 includes the following steps: According to the required current, a current control command is sent to the power module, and the charging current is monitored in real time. If the current is greater than the required current but does not reach the overcurrent protection threshold, an active disconnection command is sent to the smart circuit breaker.

[0043] Step S3 includes the following steps: The system receives overcurrent information reported by the intelligent circuit breaker and sends a command to the power module to stop supplying power. The overcurrent information is monitored in real time by the intelligent circuit breaker. When the overcurrent protection threshold is detected, the circuit breaker will actively disconnect and report the overcurrent information.

[0044] In this embodiment, when the intelligent circuit breaker detects an overcurrent (charging current greater than the overcurrent protection threshold), it actively disconnects and reports the status to the charging pile controller. The charging pile controller then issues a command based on the status to stop the power module from outputting power.

[0045] Meanwhile, if the charging pile controller detects an overcurrent (charging current greater than the required current), but the overcurrent protection threshold preset by the circuit breaker is not reached, the controller will control the smart circuit breaker to disconnect, thus providing priority protection.

[0046] Please refer to Figure 2 Embodiment two of the present invention is as follows: A charging pile with intelligent overcurrent protection includes a power module, an intelligent circuit breaker, a charging pile controller, a DC meter, and a charging gun. The power module includes a power module controller and a DC-DC power module.

[0047] In this embodiment, a charging pile with intelligent overcurrent protection mainly consists of a DC-DC power module, an intelligent circuit breaker, a DC meter, a charging gun, a charging pile controller, and a power module controller.

[0048] One end of the intelligent circuit breaker is electrically connected to the charging gun, and the other end is electrically connected to the power module; The charging pile controller is communicatively connected to the power module controller, and the power module controller is communicatively connected to the DC-DC power module.

[0049] A DC meter is connected between the intelligent circuit breaker and the charging gun, and the charging pile controller is connected to the DC meter.

[0050] The charging pile controller is communicatively connected to the power module and the smart circuit breaker.

[0051] The charging pile controller communicates with the power module controller via LAN, and the power module controller communicates with the DC-DC power module via CAN.

[0052] The charging pile controller communicates with the smart circuit breaker and with the DC meter via RS485, while the charging pile controller communicates with the electric vehicle via CAN through the charging gun.

[0053] In this embodiment: The charging pile controller is the core component of the charging pile. It has a CAN interface to receive and send messages between the electric vehicle BMS and the charging pile, and to collect information about the electric vehicle battery, including the upper limit current demand, SOC, upper limit voltage, and demand current. It also has an RS485 communication interface with the smart circuit breaker to set the protection threshold and protection design of the smart circuit breaker, provide feedback on the operating status of the smart circuit breaker, and control the opening and closing of the smart circuit breaker in real time.

[0054] A DC-DC power module provides the output power and voltage required by electric vehicles to the charging station, and can consist of one or more modules.

[0055] The intelligent circuit breaker features rapid short-circuit protection with a response time of less than 1ms; it also has a fast sampling function to collect current and quickly disconnect the main circuit in case of overcurrent. The current value and time for rapid overcurrent protection can be set to default values ​​or can be configured via an external source (such as a charging pile controller) through an RS485 communication interface; the intelligent circuit breaker can also receive on / off control via an RS485 communication interface; and it provides primary short-circuit protection in case of main component failure.

[0056] A split-type charging station is a device that connects a charging station to an electric vehicle.

[0057] A DC meter is a device for measuring the amount of electricity charged by an electric vehicle. It is connected to the charging pile controller via RS485.

[0058] The power module controller communicates with the DC-DC power module via CAN to control the start-up, shutdown, and operating power of the DC-DC power module; it also has an Ethernet communication interface to communicate with the charging pile controller, forward the operating instructions executed by the charging pile, and provide feedback on the DC-DC status, etc.

[0059] In this embodiment, the charging pile controller is communicatively connected to the power module and the smart circuit breaker, and implements the steps in the above-described method for intelligent overcurrent protection.

[0060] In summary, the present invention provides an intelligent overcurrent protection method and charging pile, which installs an intelligent circuit breaker inside the charging pile and sets the overcurrent protection threshold of the intelligent circuit breaker according to the charging specifications of the electric vehicle. At the same time, it combines the current demand of the electric vehicle to realize overcurrent protection adapted to the charging process of electric vehicles of different specifications, which greatly avoids the replacement and maintenance of electric vehicle charging circuit devices caused by overcurrent due to short circuit faults in the charging pile.

[0061] Traditional charging piles cannot prioritize disconnecting the charging pile's fuses in case of overcurrent or short circuit protection for different electric vehicles, thus failing to protect the electric vehicle's components. This invention provides an intelligent overcurrent protection method and charging pile that, even after a short circuit fault, prioritizes overcurrent protection over the electric vehicle's internal fuses for different models of electric vehicles. It allows for setting overcurrent thresholds and overcurrent time settings to adapt to the charging process of different electric vehicles, significantly reducing the need for replacement and maintenance of electric vehicle charging circuit components due to charging pile malfunctions.

[0062] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An overcurrent protection method for a charging pile, characterized in that, include: The charging pile controller receives messages between the electric vehicle's battery management system and the charging pile, and collects the electric vehicle's maximum current requirement. The charging pile controller determines whether the upper limit current demand is greater than the upper limit current of the charging pile. If so, it calculates the overcurrent protection threshold based on the upper limit current. Otherwise, it calculates the overcurrent protection threshold based on the upper limit current demand and sets the overcurrent protection threshold for the smart circuit breaker. The intelligent circuit breaker monitors the charging current. If the charging current exceeds the overcurrent protection threshold, the intelligent circuit breaker will actively disconnect and report the status to the charging pile controller.

2. The method according to claim 1, characterized in that, The overcurrent protection threshold is calculated based on the maximum current limit, including using a preset first multiple of the maximum current limit of the charging pile as the overcurrent protection threshold; The overcurrent protection threshold is calculated based on the upper limit current of the demand, including using a preset second multiple of the upper limit current of the demand as the overcurrent protection threshold.

3. The method according to claim 1, characterized in that, Setting the overcurrent protection threshold for the intelligent circuit breaker also includes: The charging pile controller sets the overcurrent protection action time for the smart circuit breaker, which is 1ms to 5ms.

4. The method according to claim 1, characterized in that, The intelligent circuit breaker actively disconnects and reports its status to the charging pile controller, followed by: The charging pile controller sends a command to the power module to stop supplying power.

5. An overcurrent protection system for a charging pile, used to implement the steps of the overcurrent protection method for a charging pile according to any one of claims 1 to 4, characterized in that, include: A charging pile includes a charging pile controller, a charging gun and a smart circuit breaker that are communicatively connected to the charging pile controller, and one end of the smart circuit breaker is electrically connected to the charging gun. An electric vehicle, connected to the charging gun, includes a battery and a battery management system, the battery management system being communicatively connected to the charging pile controller.

6. The system according to claim 5, characterized in that, Also includes: The power module includes a DC-DC power module and a power module controller. The power module controller communicates with the charging pile controller via LAN, and the DC-DC power module communicates with the power module controller via CAN. The other end of the intelligent circuit breaker is electrically connected to the DC-DC power module.

7. The system according to claim 5, characterized in that, Also includes: A DC meter is connected between the intelligent circuit breaker and the charging gun, and the charging pile controller is connected to the DC meter.

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