Charging pile with leakage current detection function

Abstract

The invention relates to a charging pile with a leakage current detection function, and belongs to the technical field of charging piles. Comprising an onboard residual current detection module used for detecting leakage current, a latch connected with the onboard residual current detection module, a logic unit connected with the latch and a CPU receiving leakage current signals output by the onboard residual current detection module, and the logic unit carries out judgment according to the state of the latch and control signals sent by the CPU. And the logic unit controls the alternating-current relay to be disconnected. It is ensured that the AC relay can be rapidly turned off when any one of the CPU control pin and the latch output pin detects the leakage current signal sent by the onboard residual current detection module, dual guarantee is provided for disconnection of the AC relay after the leakage current signal is detected, and safe use of the AC charging pile is guaranteed. And problem positioning and rapid maintenance during equipment repair are facilitated.

Description

Technical Field

[0001] The present invention relates to a charging pile with leakage current detection, belonging to the technical field of charging piles. Background Art

[0002] In a charging pile, a leakage current detection and protection system is essential. The main function of the leakage current protection system is to monitor whether there is a leakage current in the charging pile. Once a leakage current is detected in the system, the system will immediately cut off the output of the charging gun, thus ensuring the safety of the charging pile equipment, users, and electric vehicles.

[0003] The existing leakage current detection systems are as Figure 1 shown. In a charging controller system of an AC charging pile, an external leakage current protector is added. The power line is first connected to the leakage current protector and then from the leakage current protector to the AC charging controller of the AC charging pile to supply power to the AC charging controller, and the AC charging controller then supplies power to the electric vehicle through the charging gun. In this mode, when a leakage current occurs in the AC charging pile, the leakage current protector will directly cut off the input power supply in hardware. At this time, the power input of the AC charging controller will be turned off, and the external charging function will be cut off, thus realizing the leakage current protection function of the AC charging pile. However, the existing leakage current detection systems have the following problems: 1) The externally connected leakage current protection device needs to be placed in a separately designed position, occupying a certain position space, making it difficult to design the charging pile to be miniaturized. Moreover, the externally connected leakage current protection device is expensive, increasing the product cost; 2) After detecting a leakage current, the externally connected leakage current protector will quickly cut off the input power supply of the charging controller, causing the charging controller to lose its working ability due to power failure, unable to display and report the fault problems of the charging pile, making it difficult for the operation and maintenance personnel to handle the problems in a timely manner and not easy to troubleshoot.

[0004] The Chinese patent document with publication number CN112865271A discloses a controller circuit for an AC charging pile. In this method, the control circuit includes a leakage protection circuit, and the leakage protection circuit of the on-board control circuit performs leakage protection processing on the controller, improving the safety performance. It solves the problem of the high cost of the externally connected leakage current protection device, but does not consider the specific processing method of leakage detection. There is only a leakage current detection circuit, and if a fault occurs, there will be a problem of a high leakage current undetected rate and no corresponding processing method or measure to reduce the undetected rate. Summary of the Invention

[0005] The purpose of the present invention is to provide a charging pile with leakage current detection to solve the problem of high undetected rate of leakage current detection caused by possible failures in the leakage current detection circuit.

[0006] To achieve the above object, the solution of the present invention includes: The present invention provides a charging pile with leakage current detection, including an on-board residual current detection module for leakage current detection, a latch connected to the on-board residual current detection module, a logic unit connected to the latch, and a CPU that receives the leakage current signal output by the on-board residual current detection module. The CPU is also controllably connected to the logic unit, and the logic unit is controllably connected to an AC relay for externally outputting charging power. When the leakage current meets the set conditions, the on-board residual current detection module sends leakage current signals to the latch and the CPU respectively. The logic unit makes a judgment based on the state of the latch and the control signal sent by the CPU. When the CPU receives the leakage current signal and sends a control signal to the logic unit, the logic unit controls the AC relay to disconnect. When the state of the latch indicates the presence of a leakage current signal, the logic unit controls the AC relay to disconnect.

[0007] Furthermore, the CPU is also controllably connected to the latch. When the leakage current signal disappears, the CPU sends a clear instruction to the latch to clear the leakage current signal stored in the latch.

[0008] Furthermore, the CPU records the leakage current signal and reports the fault information to the cloud through a communication device.

[0009] Furthermore, it further includes an AC-DC conversion module. The AC side of the AC-DC conversion module is connected to the on-board residual current detection module or the AC bus on the grid power supply input side for taking power from the on-board residual current detection module or the AC bus on the grid power supply input side. The DC side of the AC-DC conversion module is connected to the CPU for supplying power to the CPU.

[0010] Furthermore, the on-board residual current detection module is arranged on the AC bus on the grid power supply input side or on the AC bus for externally outputting charging power. When it is arranged on the AC bus on the grid power supply input side, the charging power is externally output through the on-board residual current detection module and the AC relay in sequence. When it is arranged on the AC bus for externally outputting charging power, the charging power is externally output through the AC relay and the on-board residual current detection module in sequence.

[0011] Furthermore, the CPU is also controllably connected to the on-board residual current detection module. The CPU controls the on-board residual current detection module to turn on and off the externally output charging power, and controls the enabling of the leakage current detection function in the on-board residual current detection module during initialization.

[0012] The beneficial effects of the present invention are as follows: The present invention provides a charging pile with leakage current detection. The leakage current detection and protection circuit system can be integrally placed inside the charging controller of the charging pile, thus saving the use of space and making the overall charging pile more compact and concise. In addition, through the summary of the status of the latch and the control signal issued by the CPU in the logic unit to control the AC relay, it is ensured that when a leakage current signal sent by the on-board residual current detection module is detected on any one of the CPU control pins and the latch output pins, the AC relay can be quickly turned off, providing a double guarantee for the disconnection of the AC relay after the leakage current signal is detected, ensuring the safe use of the AC charging pile, and at the same time sending the leakage current signal to the CPU. The CPU uploads the information generated by the leakage current to the server, which is conducive to the positioning and rapid repair of problems during equipment repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of the composition of the prior art leakage current detection circuit system; Figure 2 is a schematic diagram of the composition of the leakage current detection circuit system of the present invention; Figure 3 is a schematic diagram of another connection method of the leakage current detection circuit system of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in detail clearly and completely below with reference to the accompanying drawings and embodiments.

[0015] The inventive concept of the present invention lies in: The present invention provides a charging pile with leakage current detection, which includes an on-board residual current detection module for leakage current detection, a latch connected to the on-board residual current detection module, a logic unit connected to the latch, and a CPU that receives the leakage current signal output by the on-board residual current detection module. The CPU is also connected to control the logic unit, and the logic unit is connected to control an AC relay for externally outputting charging power. When the leakage current meets the set conditions, the on-board residual current detection module sends leakage current signals to the latch and the CPU respectively. The logic unit makes a judgment based on the latch state and the control signal sent by the CPU. When the CPU receives the leakage current signal and sends a control signal to the logic unit, the logic unit controls the AC relay to disconnect. When the latch state indicates the existence of a leakage current signal, the logic unit controls the AC relay to disconnect. Among them, the leakage current detection and protection circuit system can be integrally placed inside the charging controller of the charging pile, thus saving the use of space and making the overall charging pile more compact and concise. In addition, through the summary of the latch state and the control signal sent by the CPU in the logic unit to control the AC relay, it is ensured that when any one of the CPU control pins and the latch output pins detects the leakage current signal sent by the on-board residual current detection module, the AC relay can be quickly turned off, providing a double guarantee for the disconnection of the AC relay after the leakage current signal is detected, ensuring the safe use of the AC charging pile, and at the same time sending the leakage current signal to the CPU, and the CPU uploads the information generated by the leakage current to the server, which is conducive to the positioning and rapid repair of problems during equipment repair.

[0016] Embodiment 1 of a charging pile with leakage current detection: A charging pile with leakage current detection in this embodiment takes an AC charging pile as an example. This AC charging pile includes an AC charging controller, which specifically includes an on-board residual current detection module, a logic unit module, a latch, and a CPU. The entire leakage current detection and protection circuit system of the AC charging controller takes the CPU as the main control core, processes and uploads the leakage current signal, and controls the latch, the logic unit, and the leakage current detection module through the IO port pins. Among them, the CPU controls the clearing of the latch, disconnects the AC relay when a leakage current signal appears, and after the charging pile is repaired and maintained, clears the leakage current signal stored in the latch to ensure that the charging pile resumes normal operation. The CPU sends a control signal to the logic unit when receiving the leakage current signal, controls the opening of the voltage input at the leakage current detection module, and controls the enabling of the leakage current detection module during initialization.

[0017] Specifically, the on-board residual current detection module is a signal collector that collects the leakage current of the input power supply. When a leakage current occurs, the leakage current signal is transmitted to the CPU and the latch through the IO port; the latch is used to save the leakage current signal of the on-board residual current detection module; the logic unit module is responsible for logically judging the leakage current signal in the latch and the control signal output by the CPU, and then controlling the charging function of the AC charging pile; the CPU part is responsible for judging and outputting a control signal after receiving the leakage current signal, sorting out the leakage current signal, and reporting the fault information. Through the control of the AC relay by summarizing the state of the latch and the control signal sent by the CPU in the logic unit, no matter where a fault occurs in the latch circuit or the CPU, it can ensure that when any one of the CPU control pin and the latch output pin detects the leakage current signal sent by the on-board residual current detection module, the AC relay can be quickly turned off, providing double protection for the disconnection of the AC relay after the leakage current signal is detected, and ensuring the safe use of the AC charging pile.

[0018] The latch saves the leakage current signal of the on-board residual current detection module, which can prevent the situation that the AC relay cannot be turned off due to the occurrence of a leakage current but the control signal of the CPU fails to be sent in time. When the situation that the CPU does not send the control signal to disconnect the AC relay occurs, the logic unit makes a logical judgment on the leakage current signal stored in the latch. If there is a leakage current signal, a control signal to disconnect the AC relay is sent. In addition, the clearing of the leakage current signal saved in the latch is jointly affected by the CPU and the on-board residual current detection module. Only when the leakage current signal disappears and the CPU sends a control instruction to clear the latch, the latch clears the saved leakage current signal.

[0019] The logic unit makes a logical judgment on the leakage current signal saved by the latch and the control signal sent by the CPU, and then outputs an AC relay control signal. When the CPU sends a control signal, the logic unit sends a control signal to disconnect the AC relay; when the situation that the CPU does not send the control signal to disconnect the AC relay occurs, the logic unit makes a logical judgment on the leakage current signal stored in the latch. If there is a leakage current signal, a control signal to disconnect the AC relay is sent. Ensure that the AC relay can be quickly turned off when any one of the CPU control pin and the latch output pin changes.

[0020] In addition to the situation where the CPU sends a signal to turn off the AC relay when encountering a leakage current signal, when encountering other fault signals, the CPU can also send a control signal to the logic unit to turn off the AC relay. At the same time, the CPU records the leakage current signal and reports the fault information to the cloud through the communication device.

[0021] The AC charging controller of this embodiment is as Figure 2As shown below, the specific control steps are as follows: (1) Set the on-board residual current detection module on the AC bus on the input side of the grid power supply. Part of it passes through the AC-DC conversion module (i.e., the AC-DC circuit), whose AC terminal is connected to the on-board residual current detection module for taking power from the on-board residual current detection module; the DC terminal is connected to the CPU for supplying power to the CPU; the other part outputs power externally through the AC relay; therefore, the on-board residual current detection module can supply power to the CPU through the AC-DC circuit respectively and output power to the charging gun through the AC relay; (2) The leakage current signals detected by the on-board residual current detection module are respectively transmitted to the CPU and the latch. The CPU receives the leakage current signals, makes a judgment and outputs a control signal to the logic unit. The logic unit makes a logical judgment on the leakage current signal sent by the on-board residual current detection module stored in the latch and the control signal sent by the CPU. When the CPU sends a control signal, the logic unit sends a control signal to disconnect the AC relay; when the latch status is that there is a leakage current signal, the logic unit sends a control signal to disconnect the AC relay.

[0022] Embodiment 2 of the charging pile with leakage current detection: Based on Embodiment 1 of the charging pile with leakage current detection, there is another connection method for the on-board residual current detection module in this embodiment, which can also implement a charging pile with leakage current detection provided by the present invention, and its functional effect is the same as that described in Embodiment 1.

[0023] The AC charging controller in this embodiment is as Figure 3 shown below, and the specific control steps are as follows: (1) The AC-DC conversion module (i.e., the AC-DC circuit), whose AC terminal is connected to the AC bus on the input side of the grid power supply for taking power from the AC bus on the input side of the grid power supply; the DC terminal is connected to the CPU for supplying power to the CPU; one end of the AC relay is connected to the AC bus on the input side of the grid power supply, and the other end is connected to the on-board residual current detection module, so that the grid power supply input outputs charging power to the outside through the AC relay and the on-board residual current detection module in sequence to supply power to the charging gun; (2) The leakage current signals detected by the on-board residual current detection module are respectively transmitted to the CPU and the latch. The CPU receives the leakage current signals, makes a judgment and outputs a control signal to the logic unit. The logic unit makes a logical judgment on the leakage current signal sent by the on-board residual current detection module stored in the latch and the control signal sent by the CPU. When the CPU sends a control signal, the logic unit sends a control signal to disconnect the AC relay; when the latch status is that there is a leakage current signal, the logic unit sends a control signal to disconnect the AC relay.

[0024] The leakage current detection and protection circuit system can be integrated and placed inside the charging controller of the charging pile, thus saving the use of space and making the overall charging pile more compact and concise. In addition, through the summary of the status of the latch and the control signal sent by the CPU in the logic unit to control the AC relay, it is ensured that when any one of the CPU control pins and the latch output pins detects the leakage current signal sent by the on-board residual current detection module, the AC relay can be quickly turned off, providing double protection for the disconnection of the AC relay after the leakage current signal is detected, ensuring the safe use of the AC charging pile, and at the same time sending the leakage current signal to the CPU. The CPU uploads the information generated by the leakage current to the server, which is beneficial to the location and quick repair of problems during equipment repair.

[0025] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. The patent protection scope of the present invention is subject to the claims. Any equivalent structural changes made by using the description and drawings of the present invention should, by the same token, be included in the protection scope of the present invention.

Claims

1. A charging pile with leakage current detection, characterized in that: It includes an onboard residual current detection module for leakage current detection, a latch connected to the onboard residual current detection module, a logic unit connected to the latch, and a CPU receiving a leakage current signal output by the onboard residual current detection module, wherein the CPU also controls the connection to the logic unit, and the logic unit controls the connection to an AC relay for outputting charging power to the outside; when the leakage current meets the set conditions, the onboard residual current detection module sends a leakage current signal to the latch and the CPU respectively, and the logic unit makes a judgment based on the latch state and the control signal sent by the CPU. When the CPU receives the leakage current signal and sends a control signal to the logic unit, the logic unit controls the AC relay to disconnect; when the latch state is that there is a leakage current signal, the logic unit controls the AC relay to disconnect.

2. The charging pile with leakage current detection according to claim 1, characterized in that: The CPU also controls the connection latch. When the leakage current signal disappears, the CPU sends a clear instruction to the latch to clear the leakage current signal stored in the latch.

3. The charging pile with leakage current detection according to claim 1, characterized in that: The CPU records the leakage current signal and reports the fault information to the cloud through the communication device.

4. The charging pile with leakage current detection according to claim 1, characterized in that: It also includes an AC-DC conversion module, the AC end of the AC-DC conversion module is connected to the onboard residual current detection module or the AC bus on the power supply input side of the power grid, and is used to draw power from the onboard residual current detection module or the AC bus on the power supply input side of the power grid; the DC end of the AC-DC conversion module is connected to the CPU, and is used to power the CPU.

5. The charging pile with leakage current detection according to claim 1, characterized in that: The onboard residual current detection module is arranged on the AC bus on the power supply input side of the power grid or on the AC bus for outputting charging power to the outside. When it is arranged on the AC bus on the power supply input side of the power grid, the charging power is output to the outside through the onboard residual current detection module and the AC relay in sequence; when it is arranged on the AC bus for outputting charging power to the outside, the charging power is output to the outside through the AC relay and the onboard residual current detection module in sequence.

6. The charging pile with leakage current detection according to claim 5, characterized in that: The CPU also controls the connection of the onboard residual current detection module. The CPU controls the onboard residual current detection module to turn on and off the external output of charging power, and controls the enabling of the leakage current detection function in the onboard residual current detection module during initialization.

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