Relay adhesion detection circuit for single-phase and three-phase AC charging piles

Abstract

The utility model provides a relay adhesion detection circuit for single-phase and three-phase alternating current charging piles, and relates to the technical field of electric automobile alternating current charging piles, the relay adhesion detection circuit comprises a first optical coupler, a second optical coupler and a third optical coupler, the C pole of the first optical coupler, the C pole of the second optical coupler and the C pole of the third optical coupler are connected, and the C pole of the second optical coupler is connected with the C pole of the third optical coupler. A B pole and an E pole of the first optical coupler are connected, a first diode is arranged between the B pole and the E pole of the first optical coupler, the B pole of the first optical coupler is sequentially connected with a first resistor and a second resistor, and a B pole and an E pole of the second optical coupler are connected, and a second diode is arranged between the B pole and the E pole of the second optical coupler. The B pole of the second optical coupler is sequentially connected with a third resistor and a fourth resistor, the B pole and the E pole of the third optical coupler are connected, a third diode is arranged between the B pole and the E pole of the third optical coupler, and the B pole of the third optical coupler is sequentially connected with a fifth resistor and a sixth resistor. According to the utility model, whether the relay is adhered can be effectively detected.

Description

Technical Field

[0001] The utility model relates to the technical field of electric vehicle piles, and particularly relates to a relay adhesion detection circuit for single-phase and three-phase AC charging piles. Background Technique

[0002] In an electric vehicle pile, it is necessary to detect whether the relay is in a normal working state before each charging to avoid accidents. However, the currently used relay adhesion detection circuit has a high cost and a relatively complex structure.

[0003] Therefore, there is an urgent need for a relay adhesion detection circuit for single-phase and three-phase AC charging piles to solve the problems of high cost and complex structure of the existing relay adhesion detection circuit. Summary of the Utility Model

[0004] The utility model provides a relay adhesion detection circuit for single-phase and three-phase AC charging piles, which solves the problems of high cost and complex structure of the existing relay adhesion detection circuit.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0006] A relay adhesion detection circuit for single-phase and three-phase AC charging piles includes a first optocoupler, a second optocoupler and a third optocoupler. The C poles of the first optocoupler, the second optocoupler and the third optocoupler are connected. The B pole and the E pole of the first optocoupler are connected, and a first diode is arranged therebetween. The B pole of the first optocoupler is sequentially connected with a first resistor and a second resistor. The B pole and the E pole of the second optocoupler are connected, and a second diode is arranged therebetween. The B pole of the second optocoupler is sequentially connected with a third resistor and a fourth resistor. The B pole and the E pole of the third optocoupler are connected, and a third diode is arranged therebetween. The B pole of the third optocoupler is sequentially connected with a fifth resistor and a sixth resistor. The C poles of the first optocoupler, the second optocoupler and the third optocoupler are connected with a seventh resistor.

[0007] Further, the resistance values of the first resistor, the second resistor, the third resistor, the fourth resistor, the fifth resistor and the sixth resistor are 100K, and the resistance value of the seventh resistor is 75K.

[0008] To sum up, due to adopting the above technical solution, the beneficial effects of the utility model are as follows:

[0009] In actual use, the first optocoupler, the second optocoupler and the third optocoupler in the present utility model are connected to the corresponding relay outputs. The positive half-cycle of the AC voltage output by the relay causes the optocoupler to output a low-effective pulse signal consistent with the power supply frequency. When the circuit is applied to a three-phase charging pile, three optocouplers are used, and the output ends of the optocouplers are connected in parallel to reduce the cost of the circuit. When the control circuit performs adhesion detection, the relays of the live wire and the neutral wire will be respectively energized. Since the relays are not energized simultaneously, under normal circumstances, the input ends of the optocouplers will not receive voltage, and no low-level pulse will be detected at the output of the optocouplers. When a certain relay gets stuck, the input end of the optocoupler in the detection process will receive the AC voltage output by the relay, and a low-level pulse will be generated at the output of the optocoupler. In this way, the present utility model can effectively detect whether the relay is stuck at a very low cost, thus achieving... Description of the Drawings

[0010] Figure 1 It is a schematic diagram of the circuit connection structure of the present utility model. Detailed Embodiment

[0011] The present utility model will be described in detail below with reference to the drawings.

[0012] In order to make the purpose, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0013] In this embodiment, a relay adhesion detection circuit for single-phase and three-phase AC charging piles is provided, as Figure 1 shown, which includes a first optocoupler U11, a second optocoupler U15 and a third optocoupler U16. The C electrodes of the first optocoupler U11, the second optocoupler U15 and the third optocoupler U16 are connected. The B electrode and the E electrode of the first optocoupler U11 are connected, and a first diode D3 is arranged therebetween. The B electrode of the first optocoupler U11 is sequentially connected with a first resistor R83 and a second resistor R81. The B electrode and the E electrode of the second optocoupler U15 are connected, and a second diode D13 is arranged therebetween. The B electrode of the second optocoupler U15 is sequentially connected with a third resistor R72 and a fourth resistor R68. The B electrode and the E electrode of the third optocoupler U16 are connected, and a third diode D15 is arranged therebetween. The B electrode of the third optocoupler U16 is sequentially connected with a fifth resistor R78 and a sixth resistor R77. The C electrodes of the first optocoupler U11, the second optocoupler U15 and the third optocoupler U16 are connected with a seventh resistor R80.

[0014] In actual use, the first optocoupler, the second optocoupler and the third optocoupler in the present utility model are connected to the corresponding relay outputs. The positive half cycle of the AC voltage output by the relay causes the optocoupler to output a low-effective pulse signal consistent with the power frequency. When the circuit is applied to a three-phase charging pile, three optocouplers are used, and the output ends of the optocouplers are connected in parallel to reduce the cost of the circuit. When the control circuit performs adhesion detection, the relays of the live wire and the neutral wire are respectively energized. Since the relays are not energized simultaneously, under normal circumstances, the input ends of the optocouplers will not receive voltage, and no low-level pulse will be detected at the output of the optocouplers. When a certain relay is stuck, the input end of the optocoupler in the detection process will receive the AC voltage output by the relay, and a low-level pulse will be generated at the output of the optocoupler. In this way, the present utility model can effectively detect whether the relay is stuck at a very low cost, thus realizing...

[0015] For further optimization of the above embodiments, the resistance values of the first resistor R83, the second resistor R81, the third resistor R72, the fourth resistor R68, the fifth resistor R78 and the sixth resistor R77 are 100K, and the resistance value of the seventh resistor R80 is 75K.

[0016] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A relay adhesion detection circuit for single-phase and three-phase AC charging piles, characterized in that: It includes a first optical coupler U11, a second optical coupler and a third optical coupler, wherein the C poles of the first optical coupler, the second optical coupler and the third optical coupler are connected, the B pole of the first optical coupler is connected to the E pole with a first diode arranged therebetween, the B pole of the first optical coupler is sequentially connected to the first resistor and the second resistor, the B pole of the second optical coupler is connected to the E pole with a second diode arranged therebetween, the B pole of the second optical coupler is sequentially connected to the third resistor and the fourth resistor, the B pole of the third optical coupler is connected to the E pole with a third diode arranged therebetween, the B pole of the third optical coupler is sequentially connected to the fifth resistor and the sixth resistor, and the C poles of the first optical coupler, the second optical coupler and the third optical coupler are connected to the seventh resistor.

2. A relay adhesion detection circuit for single-phase and three-phase AC charging piles according to claim 1, characterized in that: The resistance values ​​of the first resistor, the second resistor, the third resistor, the fourth resistor, the fifth resistor and the sixth resistor are 100K, and the resistance value of the seventh resistor is 75K.

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