Diode existence detection circuit of charging pile

Abstract

The utility model relates to a diode existence detection circuit of a charging pile. The diode existence detection circuit comprises a CP control guide end of the charging pile; an ADC input end of the single-chip microcomputer; the positive power supply end of the operational amplifier U10 is connected to a 5V power supply, and the negative power supply end is grounded; the resistor R32 is connected between the CP control guide end and the inverting input end of the operational amplifier U10; and the resistor R36 is connected between the output end and the inverted input end of the operational amplifier U10 to form feedback.

Description

Technical Field

[0001] The utility model relates to the technical field, in particular to a diode existence detection circuit for a charging pile. Background Art

[0002] With the widespread use of charging piles, safety hazards and various accidents of old charging piles have occurred frequently, exposing urgent problems that need to be solved in charging safety.

[0003] To improve the safety and reliability of charging piles, the National Standardization Administration of China released the updated GB / T18487-2023 standard for conductive charging systems for electric vehicles in 2023. This new standard, based on the existing standard, imposes higher requirements for charging safety, such as adding the requirement for diode presence detection.

[0004] Diode presence detection involves checking for the presence of a diode on the control line (CP) before the charging station starts charging. The presence of a diode effectively prevents the charging station from misidentifying ordinary loads as electric vehicles, thereby avoiding safety incidents. For example, if a charging station mistakenly identifies a household appliance as an electric vehicle, it may output excessive voltage or current, causing damage to the appliance or even a fire. However, if a diode is present on the CP line, the unidirectional conductivity of the diode prevents the charging station from outputting current, thus preventing a safety incident.

[0005] Currently, existing charging stations generally lack diode presence detection capabilities, making them ineffective in preventing mischarging. While some charging stations can detect the presence of a load by detecting the voltage or current on the CP line, this method is susceptible to interference and lacks reliability. Summary of the Invention

[0006] In order to solve the above problems, the utility model provides a diode presence detection circuit for a charging pile, which effectively prevents the charging pile from mistakenly identifying an ordinary load as an electric vehicle, thereby preventing safety accidents caused by incorrect charging.

[0007] In order to achieve the above-mentioned purpose, the diode presence detection circuit of the charging pile designed by the present invention includes:

[0008] CP control guide terminal of charging pile;

[0009] ADC input of the microcontroller;

[0010] Operational amplifier U10, with its positive power supply terminal connected to a 5V power supply and its negative power supply terminal connected to ground;

[0011] a resistor R32 connected between the CP control pilot terminal and the inverting input terminal of the operational amplifier U10;

[0012] A resistor R36 is connected between the output terminal and the inverting input terminal of the operational amplifier U10 to form a feedback;

[0013] The non-inverting input terminal of the operational amplifier U10 is grounded, and its output terminal is also connected to the ADC input terminal of the microcontroller; the operational amplifier U10 is configured to reversely amplify the input signal of the CP control pilot terminal to a preset proportion of the original signal amplitude; the ADC input terminal of the microcontroller is used to receive the signal after reverse amplification by the operational amplifier U10, so that the microcontroller can determine the existence of the diode.

[0014] A further solution is that the operational amplifier U10 is an LMV321 rail-to-rail operational amplifier.

[0015] A further solution is that the preset ratio is -1 / 4.

[0016] A further solution is that the resistance of the resistor R32 is 402 kΩ, and the resistance of the resistor R36 is 100 kΩ.

[0017] A further solution is to further include a filter capacitor C43, one end of the filter capacitor C43 is connected to the positive power supply terminal of the operational amplifier U10, and the other end is grounded.

[0018] A further solution is that the capacitance value of the filter capacitor C43 is 100nF.

[0019] A further solution is that the input signal of the CP control guide terminal of the charging pile is -12V.

[0020] The diode presence detection circuit for charging piles designed in this utility model can accurately detect the presence of a diode on the CP line, effectively preventing the charging pile from mistakenly identifying ordinary loads as electric vehicles, thereby preventing safety accidents caused by incorrect charging. The circuit has a simple structure and can be implemented using only a few common components such as operational amplifiers, resistors, and capacitors. It is easy to integrate into existing charging pile control systems without major modifications to the original system, thus having the advantages of low cost and strong compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a circuit diagram of a diode presence detection circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0022] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0023] Example 1.

[0024] like Figure 1 As shown, the diode presence detection circuit of the charging pile described in this embodiment includes:

[0025] The CP control pilot terminal of the charging pile has an input signal of -12V;

[0026] ADC input of the microcontroller;

[0027] Operational amplifier U10, whose model is LMV321 rail-to-rail operational amplifier, has a positive power supply terminal connected to a 5V power supply, and a negative power supply terminal connected to ground;

[0028] A resistor R32 having a resistance of 402 kΩ, connected between the CP control pilot terminal and the inverting input terminal of the operational amplifier U10;

[0029] A resistor R36 having a resistance of 100 kΩ is connected between the output terminal and the inverting input terminal of the operational amplifier U10 to form a feedback;

[0030] The non-inverting input terminal of the operational amplifier U10 is grounded, and its output terminal is also connected to the ADC input terminal of the microcontroller; the operational amplifier U10 is configured to reversely amplify the input signal of the CP control pilot terminal to a preset proportion of the original signal amplitude; the ADC input terminal of the microcontroller is used to receive the signal after reverse amplification by the operational amplifier U10, so that the microcontroller can determine the existence of the diode.

[0031] When working, refer to Figure 1 As shown, the CP control pilot terminal of the charging pile outputs a -12V DC signal, and the operational amplifier U10 reversely amplifies the CP signal. In this embodiment, the preset amplification ratio is -1 / 4, so the output voltage of U10 is 3V, which is sent to the ADC input terminal of the microcontroller. The microcontroller samples the voltage through the ADC and calculates the voltage value of the CP control pilot terminal of the charging pile.

[0032] When a diode exists in the peripheral steering circuit, due to the unidirectional conductivity of the diode, the voltage at the CP control steering end remains unchanged at -12V. At this time, no current flows between the internal resistors (resistor R32 and resistor R36) and the external circuit, and no voltage divider effect is generated.

[0033] When there is no diode in the peripheral circuit, for example, when a normal load device is connected, the internal resistors (resistors R32 and R36) will form a voltage divider circuit with the external load. At this time, the voltage at the CP control guide terminal will be divided, and its value will be lower than -12V, with a typical value of -9V or -6V. By detecting this voltage change, the microcontroller can effectively determine whether there is a diode in the connected device, thereby distinguishing between electric vehicles and normal load devices.

[0034] In some embodiments, as Figure 1 As shown, the circuit further includes a filter capacitor C43 having a capacitance of 100 nF. One end of the filter capacitor C43 is connected to the positive power supply terminal of the operational amplifier U10, and the other end is grounded. Filter capacitor C43 effectively filters high-frequency noise on the power supply line 5, preventing it from interfering with the operation of the operational amplifier U10 and improving the circuit's anti-interference capability. Specifically, after filtering out the power supply noise, the operational amplifier U10 operates more stably and produces a purer output signal, thereby improving the accuracy and reliability of diode presence detection.

[0035] The diode presence detection circuit for a charging pile provided in this embodiment can accurately detect the presence of a diode on the CP line, effectively preventing the charging pile from mistakenly identifying ordinary loads as electric vehicles, thereby preventing safety accidents caused by incorrect charging. The circuit has a simple structure and can be implemented using only a few common components such as operational amplifiers, resistors, and capacitors. It is easy to integrate into existing charging pile control systems without major modifications to the original system, thus offering the advantages of low cost and strong compatibility.

[0036] In the description of the present invention, it should be noted that the terms "vertical", "up", "down", "horizontal", etc. indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0037] It should also be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0038] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A diode presence detection circuit for a charging pile, comprising: CP control guide terminal of charging pile; ADC input of the microcontroller; Operational amplifier U10, with its positive power supply terminal connected to a 5V power supply and its negative power supply terminal connected to ground; a resistor R32 connected between the CP control pilot terminal and the inverting input terminal of the operational amplifier U10; A resistor R36 is connected between the output terminal and the inverting input terminal of the operational amplifier U10 to form a feedback; The non-inverting input terminal of the operational amplifier U10 is grounded, and its output terminal is also connected to the ADC input terminal of the microcontroller; the operational amplifier U10 is configured to reversely amplify the input signal of the CP control pilot terminal to a preset proportion of the original signal amplitude; the ADC input terminal of the microcontroller is used to receive the signal after reverse amplification by the operational amplifier U10, so that the microcontroller can determine the existence of the diode.

2. The diode presence detection circuit of the charging pile according to claim 1, characterized in that: The operational amplifier U10 is an LMV321 rail-to-rail operational amplifier.

3. The diode presence detection circuit of the charging pile according to claim 1, characterized in that: The preset ratio is -1 / 4.

4. The diode presence detection circuit of the charging pile according to claim 1, characterized in that: The resistance of the resistor R32 is 402 kΩ, and the resistance of the resistor R36 is 100 kΩ.

5. The diode presence detection circuit of the charging pile according to claim 1, characterized in that: The filter capacitor C43 is further included. One end of the filter capacitor C43 is connected to the positive power supply terminal of the operational amplifier U10, and the other end is grounded.

6. The diode presence detection circuit of the charging pile according to claim 5, characterized in that: The capacitance value of the filter capacitor C43 is 100nF.

7. The diode presence detection circuit of the charging pile according to claim 1, characterized in that: The input signal of the CP control pilot terminal of the charging pile is -12V.

Images