Before-charging output short circuit detection circuit of charging pile suitable for single-phase power input

Abstract

The utility model relates to the technical field of short circuit detection, in particular to an output short circuit detection circuit before charging of a charging pile suitable for single-phase power input, which comprises a relay K5, a triode V1, a first voltage dividing unit, a second voltage dividing unit and a third voltage dividing unit, the base electrode of the triode V1 is connected with an I / O port of an external MCU module, and the first voltage dividing unit is connected with one end of a first contact of a relay K5, one end of a second contact of the relay K5, the output end of an external relay K1, the output end of an external relay K2 and the input end of a charging pile. And the second voltage dividing unit is connected with the other end of the second contact of the relay K5, the third voltage dividing unit and a voltage acquisition end of an external MCU module, so that a short-circuit fault among wires at the end of the charging pile can be prevented, and potential safety hazards caused by wrong electrification of the charging pile can be avoided.

Description

Technical Field

[0001] This utility model relates to the field of short circuit detection technology, and in particular to a short circuit detection circuit for the output of a charging pile before charging, suitable for single-phase power input. Background Technology

[0002] The new national standard GB44263-2024 for AC charging piles requires that "AC power supply equipment should not charge when a short circuit occurs in the AC output circuit before energy transmission." Currently, domestic AC charging piles on the market do not have output circuit detection before charging. In customer applications, short circuits may occur between the lines at the charging pile end. Without pre-charging detection, the charging pile end will close the relay to charge after detecting that the control guide CP line is connected normally. Although there is short circuit detection after normal charging, it may be too late, which poses a serious safety hazard. Therefore, it is urgent to add a short circuit detection function before charging. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a short circuit detection circuit for the output of a charging pile before charging, which is suitable for single-phase power input and can prevent short circuit faults between the lines at the charging pile end, so as to avoid the charging pile being malfunctioning and causing safety hazards.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0005] A short-circuit detection circuit for the output of a charging pile before charging, suitable for single-phase power input, includes a relay K5, a transistor V1, a first voltage divider unit, a second voltage divider unit, and a third voltage divider unit;

[0006] One end of the coil of the relay K5 is connected to the collector of the transistor V1, and the base of the transistor V1 is connected to the I / O port of the peripheral MCU module.

[0007] The first voltage divider unit is connected to one end of the first contact of relay K5, one end of the second contact of relay K5, the output terminal of peripheral relay K1, the output terminal of peripheral relay K2 and the input terminal of charging gun respectively. The second voltage divider unit is connected to the other end of the second contact of relay K5, the third voltage divider unit and the voltage acquisition terminal of peripheral MCU module respectively.

[0008] The MCU module is connected to relays K1 and K2 and the charging gun respectively. The input terminal of relay K1 is connected to the live wire of the single-phase power supply, and the input terminal of relay K2 is connected to the neutral wire of the single-phase power supply.

[0009] Furthermore, it also includes a diode D1, the anode of which is connected to one end of the coil of relay K5 and the collector of transistor V1, and the cathode of diode D1 is connected to the other end of the coil of relay K5 and the cathode of diode D1 is connected to a preset DC power supply.

[0010] Furthermore, it also includes a resistor R214, and the other end of the first contact of the relay K5 is connected to a preset DC power supply through the resistor R214.

[0011] Furthermore, the first voltage divider unit includes resistors R201, R202, and R203. One end of resistor R201 is connected to one end of the first contact of relay K5, the output terminal of peripheral relay K1, and the input terminal of the charging gun, respectively. The other end of resistor R201 is connected to one end of resistor R202. The other end of resistor R202 is connected to one end of resistor R203. The other end of resistor R203 is connected to one end of the second contact of relay K5, the output terminal of peripheral relay K2, and the input terminal of the charging gun, respectively.

[0012] Furthermore, the second voltage divider unit includes resistors R210, R211, and R212. One end of resistor R210 is connected to the other end of the second contact of relay K5, the other end of resistor R210 is connected to one end of resistor R211, the other end of resistor R211 is connected to one end of resistor R212, and the other end of resistor R212 is connected to the voltage acquisition terminal of the peripheral MCU module.

[0013] Furthermore, the third voltage divider unit includes a resistor R213, one end of which is connected to the voltage acquisition terminal of the second voltage divider unit and the MCU module of the peripheral device, and the other end of which is grounded.

[0014] Furthermore, the third voltage divider unit also includes a capacitor C130. One end of the capacitor C130 is connected to the second voltage divider unit, one end of the resistor R213, and the voltage acquisition terminal of the peripheral MCU module. The other end of the capacitor C130 is connected to the other end of the resistor R213 and grounded.

[0015] Furthermore, the third voltage divider unit also includes a Zener diode (TVS). The cathode of the Zener diode (TVS) is connected to the second voltage divider unit, one end of the resistor R213, and the voltage acquisition terminal of the peripheral MCU module, respectively. The anode of the Zener diode (TVS) is connected to the other end of the resistor R213, and the anode of the Zener diode (TVS) is grounded.

[0016] Furthermore, it also includes resistors R215 and R216. One end of resistor R215 is connected to the I / O port of the MCU module of the peripheral device, and the other end of resistor R215 is connected to one end of resistor R216 and the base of transistor V1, respectively. The other end of resistor R216 is connected to the emitter of transistor V1 and the other end of resistor R216 is grounded.

[0017] Furthermore, the other end of the coil of the relay K5 is connected to a preset DC power supply.

[0018] The beneficial effects of this utility model are as follows:

[0019] This solution uses relay K5, transistor V1, and three voltage divider units. Each time the charging pile is powered on, or when the charging gun is plugged in after power-on (when relays K1 and K2 are not closed), a high-level signal is output from the MCU module's I / O port. This turns on transistor V1, activates relay K5, and closes its first and second contacts. When there is no output short circuit, the voltage is divided by the first, second, and third voltage divider units, allowing the MCU module's voltage acquisition terminal to acquire a reference voltage. If the reference voltage acquired by the MCU module's voltage acquisition terminal differs from the reference voltage, a short circuit is detected, requiring an alarm and fault resolution before normal charging can resume. This prevents short circuits between lines at the charging pile, avoiding potential safety hazards caused by accidental power-on. Attached Figure Description

[0020] Figure 1 This is a connection block diagram of the short-circuit detection circuit for the output of a charging pile before charging, which is applicable to single-phase power input according to this utility model.

[0021] Figure 2 The circuit diagram of the short-circuit detection circuit for charging piles with single-phase power input is shown in this utility model.

[0022] Label Explanation:

[0023] 1. First voltage divider unit; 2. Second voltage divider unit; 3. MCU module; 4. Charging gun; 5. AD-DC power supply module; 6. Third voltage divider unit. Detailed Implementation

[0024] To explain in detail the technical content, objectives, and effects of this utility model, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0025] Please refer to Figure 1 as well as Figure 2A short-circuit detection circuit for the output of a charging pile before charging, suitable for single-phase power input, includes a relay K5, a transistor V1, a first voltage divider unit, a second voltage divider unit, and a third voltage divider unit;

[0026] One end of the coil of the relay K5 is connected to the collector of the transistor V1, and the base of the transistor V1 is connected to the I / O port of the peripheral MCU module.

[0027] The first voltage divider unit is connected to one end of the first contact of relay K5, one end of the second contact of relay K5, the output terminal of peripheral relay K1, the output terminal of peripheral relay K2 and the input terminal of charging gun respectively. The second voltage divider unit is connected to the other end of the second contact of relay K5, the third voltage divider unit and the voltage acquisition terminal of peripheral MCU module respectively.

[0028] The MCU module is connected to relays K1 and K2 and the charging gun respectively. The input terminal of relay K1 is connected to the live wire of the single-phase power supply, and the input terminal of relay K2 is connected to the neutral wire of the single-phase power supply.

[0029] As can be seen from the above description, the beneficial effects of this utility model are as follows:

[0030] This solution uses relay K5, transistor V1, and three voltage divider units. Each time the charging pile is powered on, or when the charging gun is plugged in after power-on (when relays K1 and K2 are not closed), a high-level signal is output from the MCU module's I / O port. This turns on transistor V1, activates relay K5, and closes its first and second contacts. When there is no output short circuit, the voltage is divided by the first, second, and third voltage divider units, allowing the MCU module's voltage acquisition terminal to acquire a reference voltage. If the reference voltage acquired by the MCU module's voltage acquisition terminal differs from the reference voltage, a short circuit is detected, requiring an alarm and fault resolution before normal charging can resume. This prevents short circuits between lines at the charging pile, avoiding potential safety hazards caused by accidental power-on.

[0031] Furthermore, it also includes a diode D1, the anode of which is connected to one end of the coil of relay K5 and the collector of transistor V1, and the cathode of diode D1 is connected to the other end of the coil of relay K5 and the cathode of diode D1 is connected to a preset DC power supply.

[0032] As can be seen from the above description, diode D1 can be used to suppress the self-induced electromotive force generated by the coil of relay K5.

[0033] Furthermore, it also includes a resistor R214, and the other end of the first contact of the relay K5 is connected to a preset DC power supply through the resistor R214.

[0034] As can be seen from the above description, resistor R214 can prevent the DC12V power supply from being short-circuited to ground when L1_OUT is short-circuited to ground.

[0035] Furthermore, the first voltage divider unit includes resistors R201, R202, and R203. One end of resistor R201 is connected to one end of the first contact of relay K5, the output terminal of peripheral relay K1, and the input terminal of the charging gun, respectively. The other end of resistor R201 is connected to one end of resistor R202. The other end of resistor R202 is connected to one end of resistor R203. The other end of resistor R203 is connected to one end of the second contact of relay K5, the output terminal of peripheral relay K2, and the input terminal of the charging gun, respectively.

[0036] Furthermore, the second voltage divider unit includes resistors R210, R211, and R212. One end of resistor R210 is connected to the other end of the second contact of relay K5, the other end of resistor R210 is connected to one end of resistor R211, the other end of resistor R211 is connected to one end of resistor R212, and the other end of resistor R212 is connected to the voltage acquisition terminal of the peripheral MCU module.

[0037] Furthermore, the third voltage divider unit includes a resistor R213, one end of which is connected to the voltage acquisition terminal of the second voltage divider unit and the MCU module of the peripheral device, and the other end of which is grounded.

[0038] As can be seen from the above description, resistor R213 is a voltage divider pull-down resistor used to adjust the voltage sampling value of the MCU module.

[0039] Furthermore, the third voltage divider unit also includes a capacitor C130. One end of the capacitor C130 is connected to the second voltage divider unit, one end of the resistor R213, and the voltage acquisition terminal of the peripheral MCU module. The other end of the capacitor C130 is connected to the other end of the resistor R213 and grounded.

[0040] As can be seen from the above description, capacitor C130 acts as a filter and provides anti-interference protection for the voltage acquisition terminal of the MCU module.

[0041] Furthermore, the third voltage divider unit also includes a Zener diode (TVS). The cathode of the Zener diode (TVS) is connected to the second voltage divider unit, one end of the resistor R213, and the voltage acquisition terminal of the peripheral MCU module, respectively. The anode of the Zener diode (TVS) is connected to the other end of the resistor R213, and the anode of the Zener diode (TVS) is grounded.

[0042] As can be seen from the above description, a Zener diode (TVS) can prevent excessive voltage in a circuit, thereby protecting electronic components from damage.

[0043] Furthermore, it also includes resistors R215 and R216. One end of resistor R215 is connected to the I / O port of the MCU module of the peripheral device, and the other end of resistor R215 is connected to one end of resistor R216 and the base of transistor V1, respectively. The other end of resistor R216 is connected to the emitter of transistor V1 and the other end of resistor R216 is grounded.

[0044] As can be seen from the above description, resistors R215 and R216 are used to limit the current and divide the voltage at the base of transistor V1.

[0045] Furthermore, the other end of the coil of the relay K5 is connected to a preset DC power supply.

[0046] Please refer to Figure 1 and Figure 2 As shown, Embodiment 1 of this utility model is as follows:

[0047] Please refer to Figure 1 and Figure 2 A short-circuit detection circuit for the output of a charging pile before charging, suitable for single-phase power input, includes a relay K5, a transistor V1, a first voltage divider unit 1, a second voltage divider unit 2, and a third voltage divider unit 6.

[0048] Please refer to Figure 2 One end of the coil of the relay K5 is connected to the collector of the transistor V1, and the base of the transistor V1 is connected to the I / O port of the peripheral MCU module 3.

[0049] Please refer to Figure 2 The first voltage divider unit 1 is connected to one end of the first contact of relay K5, one end of the second contact of relay K5, the output terminal of peripheral relay K1, the output terminal of peripheral relay K2 and the input terminal of charging gun 4 respectively. The second voltage divider unit 2 is connected to the other end of the second contact of relay K5, the third voltage divider unit 6 and the voltage acquisition terminal of peripheral MCU module 3 respectively.

[0050] Please refer to Figure 1The MCU module 3 is connected to relays K1 and K2 and charging gun 4 respectively. The input terminal of relay K1 is connected to the live wire of the single-phase power supply, and the input terminal of relay K2 is connected to the neutral wire of the single-phase power supply.

[0051] Please refer to Figure 2 It also includes a diode D1, the anode of which is connected to one end of the coil of relay K5 and the collector of transistor V1, and the cathode of which is connected to the other end of the coil of relay K5 and connected to a preset DC power supply.

[0052] Please refer to Figure 2 It also includes a resistor R214, and the other end of the first contact of the relay K5 is connected to a preset DC power supply through the resistor R214.

[0053] Please refer to Figure 2 The first voltage divider unit 1 includes resistors R201, R202, and R203. One end of resistor R201 is connected to one end of the first contact of relay K5, the output terminal of peripheral relay K1, and the input terminal of charging gun 4. The other end of resistor R201 is connected to one end of resistor R202. The other end of resistor R202 is connected to one end of resistor R203. The other end of resistor R203 is connected to one end of the second contact of relay K5, the output terminal of peripheral relay K2, and the input terminal of charging gun 4.

[0054] Please refer to Figure 2 The second voltage divider unit 2 includes resistors R210, R211, and R212. One end of resistor R210 is connected to the other end of the second contact of relay K5. The other end of resistor R210 is connected to one end of resistor R211. The other end of resistor R211 is connected to one end of resistor R212. The other end of resistor R212 is connected to the voltage acquisition terminal of the peripheral MCU module 3.

[0055] Please refer to Figure 2 The third voltage divider unit 6 includes a resistor R213. One end of the resistor R213 is connected to the other end of the resistor R212 and the voltage acquisition terminal of the peripheral MCU module 3, and the other end of the resistor R213 is grounded.

[0056] Please refer to Figure 2 The third voltage divider unit 6 also includes a capacitor C130. One end of the capacitor C130 is connected to the voltage acquisition terminal of the second voltage divider unit 2, one end of the resistor R213, and the MCU module 3 of the peripheral device. The other end of the capacitor C130 is connected to the other end of the resistor R213 and the other end of the capacitor C130 is grounded.

[0057] Please refer to Figure 2 The third voltage divider unit 6 also includes a Zener diode (TVS). The cathode of the Zener diode (TVS) is connected to the second voltage divider unit 2, one end of the resistor R213, and the voltage acquisition terminal of the peripheral MCU module 3, respectively. The anode of the Zener diode (TVS) is connected to the other end of the resistor R213 and the anode of the Zener diode (TVS) is grounded.

[0058] Please refer to Figure 2 It also includes resistors R215 and R216. One end of resistor R215 is connected to the I / O port of the MCU module 3 of the peripheral device. The other end of resistor R215 is connected to one end of resistor R216 and the base of transistor V1, respectively. The other end of resistor R216 is connected to the emitter of transistor V1 and the other end of resistor R216 is grounded.

[0059] Please refer to Figure 2 The other end of the coil of the relay K5 is connected to a preset DC power supply.

[0060] Please refer to Figure 1 The MCU module 3 is connected to the AC-DC power supply module and is powered by the AC-DC power supply module.

[0061] The working principle of the above-mentioned short-circuit detection circuit for charging piles with single-phase power input before charging is as follows:

[0062] Each time the charging pile 4 is powered on, or when the charging gun is plugged in after power-on (at this time, the contacts of relays K1 and K2 are not closed), a high level is output from the I / O port of MCU module 3, turning on transistor V1 and activating relay K5. The first and second contacts of relay K5 are both closed. When there is no output short circuit, the voltage is divided by the first voltage divider unit 1, the second voltage divider unit 2, and the third voltage divider unit 6, allowing the voltage acquisition terminal of MCU module 3 to acquire the reference voltage (the voltage value acquired by the voltage acquisition terminal of MCU module 3 is adjusted by the third voltage divider unit 6). The ADC voltage acquisition calculation formula of MCU module 3 is: 12 * pull-down resistor / (pull-up resistor + pull-down resistor), where resistors R201, R202, R203, R210, R211, and R212 are pull-up resistors, and resistor R213 is a pull-down resistor. The reference voltage U... ADC =12*R213 / (R214+R201+R202+R203+R210+R211+R212+R213), except for resistor R214 which is 10KΩ, all other resistors are 1.5MΩ. U can then be calculated. ADC =1.71V. If the voltage collected by the voltage acquisition terminal of MCU module 3 is not equal to 1.71V, it can be determined that there is a short circuit in the output. An alarm needs to be triggered to troubleshoot the problem before normal charging can proceed.

[0063] In summary, this utility model provides a short-circuit detection circuit for charging piles with single-phase power input before charging. By setting up relay K5, transistor V1, a first voltage divider unit, a second voltage divider unit, and a third voltage divider unit, a high-level signal is output from the I / O port of the MCU module each time the charging pile is powered on or when the charging gun is plugged in after power-on (when relays K1 and K2 are not closed). This turns on transistor V1, activates relay K5, and closes both the first and second contacts of relay K5. When there is no output short circuit, the voltage is divided by the first, second, and third voltage divider units, allowing the voltage acquisition terminal of the MCU module to acquire a reference voltage. If the reference voltage acquired by the voltage acquisition terminal of the MCU module is different from the reference voltage, a short circuit can be detected at the output, requiring an alarm to be triggered and the fault to be cleared before normal charging can proceed. This prevents short circuits between the lines at the charging pile, thus avoiding potential safety hazards caused by accidental power-on of the charging pile.

[0064] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent modifications made based on the content of this utility model specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A short-circuit detection circuit for the output of a charging pile before charging, suitable for single-phase power input, characterized in that, Includes relay K5, transistor V1, first voltage divider unit, second voltage divider unit, and third voltage divider unit; One end of the coil of the relay K5 is connected to the collector of the transistor V1, and the base of the transistor V1 is connected to the I / O port of the peripheral MCU module. The first voltage divider unit is connected to one end of the first contact of relay K5, one end of the second contact of relay K5, the output terminal of peripheral relay K1, the output terminal of peripheral relay K2 and the input terminal of charging gun respectively. The second voltage divider unit is connected to the other end of the second contact of relay K5, the third voltage divider unit and the voltage acquisition terminal of peripheral MCU module respectively. The MCU module is connected to relays K1 and K2 and the charging gun respectively. The input terminal of relay K1 is connected to the live wire of the single-phase power supply, and the input terminal of relay K2 is connected to the neutral wire of the single-phase power supply.

2. The short-circuit detection circuit for charging piles before charging, applicable to single-phase power input, as described in claim 1, is characterized in that... It also includes a diode D1, the anode of which is connected to one end of the coil of relay K5 and the collector of transistor V1, and the cathode of diode D1 is connected to the other end of the coil of relay K5 and the cathode of diode D1 is connected to a preset DC power supply.

3. The short-circuit detection circuit for charging piles before charging, applicable to single-phase power input, as described in claim 1, is characterized in that... It also includes a resistor R214, and the other end of the first contact of the relay K5 is connected to a preset DC power supply through the resistor R214.

4. The short-circuit detection circuit for charging piles before charging, applicable to single-phase power input, as described in claim 1, is characterized in that... The first voltage divider unit includes resistors R201, R202, and R203. One end of resistor R201 is connected to one end of the first contact of relay K5, the output terminal of peripheral relay K1, and the input terminal of the charging gun. The other end of resistor R201 is connected to one end of resistor R202. The other end of resistor R202 is connected to one end of resistor R203. The other end of resistor R203 is connected to one end of the second contact of relay K5, the output terminal of peripheral relay K2, and the input terminal of the charging gun.

5. The short-circuit detection circuit for charging piles before charging, applicable to single-phase power input, as described in claim 1, is characterized in that... The second voltage divider unit includes resistors R210, R211, and R212. One end of resistor R210 is connected to the other end of the second contact of relay K5. The other end of resistor R210 is connected to one end of resistor R211. The other end of resistor R211 is connected to one end of resistor R212. The other end of resistor R212 is connected to the voltage acquisition terminal of the MCU module of the peripheral device.

6. The short-circuit detection circuit for charging piles before charging, applicable to single-phase power input, as described in claim 1, is characterized in that... The third voltage divider unit includes a resistor R213. One end of the resistor R213 is connected to the voltage acquisition terminal of the second voltage divider unit and the MCU module of the peripheral device, respectively, and the other end of the resistor R213 is grounded.

7. The short-circuit detection circuit for charging piles before charging, applicable to single-phase power input, as described in claim 6, is characterized in that... The third voltage divider unit also includes a capacitor C130. One end of the capacitor C130 is connected to the second voltage divider unit, one end of the resistor R213, and the voltage acquisition terminal of the peripheral MCU module. The other end of the capacitor C130 is connected to the other end of the resistor R213 and grounded.

8. The short-circuit detection circuit for charging pile output before charging, applicable to single-phase power input, as described in claim 6, is characterized in that... The third voltage divider unit also includes a Zener diode (TVS). The cathode of the Zener diode (TVS) is connected to the second voltage divider unit, one end of the resistor R213, and the voltage acquisition terminal of the peripheral MCU module, respectively. The anode of the Zener diode (TVS) is connected to the other end of the resistor R213, and the anode of the Zener diode (TVS) is grounded.

9. The short-circuit detection circuit for charging piles before charging, applicable to single-phase power input, as described in claim 1, is characterized in that... It also includes resistors R215 and R216. One end of resistor R215 is connected to the I / O port of the MCU module of the peripheral device. The other end of resistor R215 is connected to one end of resistor R216 and the base of transistor V1, respectively. The other end of resistor R216 is connected to the emitter of transistor V1 and the other end of resistor R216 is grounded.

10. The short-circuit detection circuit for charging piles before charging, applicable to single-phase power input, as described in claim 1, is characterized in that... The other end of the coil of the relay K5 is connected to a preset DC power supply.

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