Combination switch control circuit of charging pile relay

Abstract

The utility model discloses a composite switch control circuit of a charging pile relay, which relates to the technical field of electronic circuits, and is characterized in that a first relay K1 is connected in series with a second relay K2, the second relay K2 is connected in parallel with a thyristor Q1, the thyristor Q1 is connected in parallel with an output optocoupler U1, and the thyristor Q1 can be driven by the output optocoupler U1. The method comprises the following steps: ensuring that closing and opening of a thyristor Q1 are executed at a zero voltage position, enabling an output optocoupler U1 to have a zero cross trigger function, in a charging process, firstly closing a first relay K1, secondly controlling whether the thyristor Q1 starts to be switched on or not through the output optocoupler U1 to supply power to a rear stage, and finally controlling closing of a second relay K2, when charging is completed, firstly opening the second relay K2, and then opening the second relay K2 through the output optocoupler U1 to supply power to the rear stage. And secondly, the thyristor Q1 is switched off, and then the first relay K1 is controlled to be switched off, so that arcing and adhesion phenomena caused by switching-on and switching-off of the relays under the on-load condition are finally avoided, and the probability of damage to contacts of the relays is reduced.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuit technology, and in particular to a composite switch control circuit for a charging pile relay. Background Technology

[0002] As new energy vehicles become increasingly popular, the market share of charging piles is constantly increasing. However, during the use of charging piles, if abnormal conditions cause the relay to disconnect or engage under load, arcing may occur, leading to relay contact sticking, which affects the normal operation of the charging pile and user safety. Therefore, it is necessary to effectively avoid relay sticking problems caused by abnormal operation.

[0003] Relays are commonly used "switch" control devices in charging piles, and the contacts are the most important and also the most easily damaged part of the relay. Sparking at relay contacts occurs because the contacts bounce continuously when the relay is engaged, constantly making and breaking contact, thus generating large sparks. This sparking is most pronounced when the relay is closed during AC voltage peaks or troughs. Therefore, ensuring the load closes at the AC voltage zero point can significantly reduce sparking. Utility Model Content

[0004] In order to overcome the problem that during the use of charging piles, abnormal conditions may cause the relay to disconnect or engage under load, which may generate arcing, causing the relay contacts to stick together, affecting the normal operation of the charging pile and user safety, the present invention provides a composite switch control circuit for charging pile relays that can avoid the arcing and sticking phenomena caused by the relay closing or opening under load, thereby reducing the probability of relay contact damage.

[0005] To solve the above-mentioned technical problems, this utility model provides a composite switch control circuit for a charging pile relay, including a first relay K1, a second relay K2, a thyristor Q1 and an output optocoupler U1. The first relay K1 and the second relay K2 are connected in series, the second relay K2 is connected in parallel with the thyristor Q1, and the thyristor Q1 is connected in parallel with the output optocoupler U1.

[0006] Preferably, the thyristor Q1 is a bidirectional thyristor, and a third resistor R3 is connected in series between the gate (G) and the main electrode T1 of the bidirectional thyristor. The gate (G) and the main electrode T2 of the bidirectional thyristor are connected in series with the output optocoupler U1 through a second resistor R2.

[0007] Specifically, the use of the second resistor R2 and the third resistor R3 plays a certain role in current limiting and provides a certain degree of protection for the circuit.

[0008] Preferably, the output optocoupler U1 is a silicon controlled rectifier (SCR) output optocoupler, and the second control signal CTR2 is connected in series with the pin 2 of the output optocoupler U1 through the first resistor R1. The pins 4 and 6 of the output optocoupler U1 are connected in series with the thyristor Q1.

[0009] Specifically, pin 2 of the output optocoupler U1 is connected in series with a second control signal CTR2 through a first resistor R1. The first resistor R1 is used for current limiting, which further meets the starting current requirements of the output optocoupler U1 and also provides a certain degree of protection for the output optocoupler U1.

[0010] Preferably, pin 2 and pin 1 of the first relay K1 are connected to the live wire and the neutral wire, respectively, and pin 4 of the first relay K1 is connected to the first control signal CTR1.

[0011] Preferably, the second relay K2 is a magnetic latching relay, pin 4 of the second relay K2 is connected to the first relay K1, pin 3 of the second relay K2 is connected to the thyristor Q1, and pins 1 and 2 of the second relay K2 are respectively connected to a third control signal CTR3 and a fourth control signal CTR4.

[0012] Preferably, the second relay K2 is connected in series with a load R4.

[0013] Specifically, the second relay K2 is connected in series with the load R4, so that the second relay K2 and the thyristor Q1 can be connected in parallel to effectively shunt the current, which greatly reduces the heat loss of the thyristor Q1 and also reduces the risk of the thyristor Q1 being broken down.

[0014] Preferably, the first relay K1 is model AHES4191, the second relay K2 is model HFE10-1 / 12-HST-L2, the thyristor Q1 is model BTA440Z-800BTQ, and the output optocoupler U1 is model MOC3083SR2M.

[0015] Preferably, pin 1 of the output optocoupler U1, pin 5 of the first relay K1, and pin 5 of the second relay K2 are respectively connected to a power supply, which is VCC-12V.

[0016] Preferably, the power consumption of the load R4 is 7KW.

[0017] Preferably, the resistance of the first resistor R1 is 1KΩ, and the resistance of the second resistor R2 and the third resistor R3 are both 360Ω.

[0018] Beneficial effects

[0019] This invention sets a first relay K1 and a second relay K2 in series, a second relay K2 in parallel with a thyristor Q1, and a thyristor Q1 in parallel with an output optocoupler U1. The drive of the thyristor Q1 can be controlled by the output optocoupler U1, ensuring that the thyristor Q1 closes and opens at zero voltage. The output optocoupler U1 has a zero-cross trigger function. During charging, the first relay K1 is first engaged, then the output optocoupler U1 controls whether the thyristor Q1 starts conducting to supply power to the next stage, and finally the second relay K2 is engaged. When charging is complete, the second relay K2 is first disengaged, then the thyristor Q1 is disengaged, and then the first relay K1 is disengaged. Ultimately, this avoids arcing and sticking caused by the relays closing and opening under load, thereby reducing the probability of relay contact damage.

[0020] The first relay K1 ensures that the circuit meets the electrical clearance requirements of safety regulations.

[0021] The second relay K2 is connected in parallel with the thyristor Q1, and the load R4 is a 7KW load, which realizes the parallel current shunting of the thyristor Q1, reduces the heat loss of the thyristor Q1, and at the same time, the circuit reduces the risk of the thyristor Q1 being broken down. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a circuit diagram of a conventional relay opening and closing control circuit for a charging pile.

[0024] Figure 2 This is a circuit diagram of the composite switch control circuit of the charging pile relay in this utility model. Detailed Implementation

[0025] To further understand the present invention, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are merely illustrative and not intended to limit the scope of the invention.

[0026] Figure 1 This is a typical relay switching control circuit diagram for charging piles, such as... Figure 1As shown, the circuit includes a third relay K3 and a resistor R5. Pins 1 and 2 of the third relay K3 are connected to the neutral and live wires of the power supply, respectively. Pins 7 and 8 of the third relay K3 are connected in series with a resistor R5. Although the circuit is simple, it is prone to arcing and sticking when the relay is engaged or disengaged during charging, which has a significant impact on the power grid. The relay has the lowest power when engaged at zero voltage. To avoid arcing of the relay, this invention proposes a composite switch control circuit for the charging pile relay, which can ensure that the relay closes and opens at zero voltage, avoiding arcing and sticking.

[0027] Example 1

[0028] A composite switch control circuit for a charging pile relay, such as Figure 2 As shown, it includes a first relay K1, a second relay K2, a thyristor Q1, and an output optocoupler U1. The first relay K1 and the second relay K2 are connected in series, the second relay K2 is connected in parallel with the thyristor Q1, and the thyristor Q1 is connected in parallel with the output optocoupler U1.

[0029] The thyristor Q1 is a bidirectional thyristor. A third resistor R3 is connected in series between the gate (G) and the main electrode T1 of the bidirectional thyristor. The gate (G) and the main electrode T2 of the bidirectional thyristor are connected in series with the output optocoupler U1 through a second resistor R2.

[0030] Specifically, the use of the second resistor R2 and the third resistor R3 plays a certain role in current limiting and provides a certain degree of protection for the circuit.

[0031] The output optocoupler U1 is a silicon controlled rectifier (SCR) output optocoupler. Pin 2 of the output optocoupler U1 is connected in series with a second control signal CTR2 through a first resistor R1. Pins 4 and 6 of the output optocoupler U1 are connected in series with the thyristor Q1.

[0032] Specifically, pin 2 of the output optocoupler U1 is connected in series with a second control signal CTR2 through a first resistor R1. The first resistor R1 is used for current limiting, which further meets the starting current requirements of the output optocoupler U1 and also provides a certain degree of protection for the output optocoupler U1.

[0033] Pin 2 and pin 1 of the first relay K1 are connected to the live wire and the neutral wire, respectively, and pin 4 of the first relay K1 is connected to the first control signal CTR1.

[0034] The second relay K2 is a magnetic latching relay. Pin 4 of the second relay K2 is connected to the first relay K1, and pin 3 of the second relay K2 is connected to the thyristor Q1. Pins 1 and 2 of the second relay K2 are respectively connected to the third control signal CTR3 and the fourth control signal CTR4.

[0035] The second relay K2 is connected in series with the load R4.

[0036] Specifically, the second relay K2 is connected in series with the load R4, so that the second relay K2 and the thyristor Q1 can be connected in parallel to effectively shunt the current, which greatly reduces the heat loss of the thyristor Q1 and also reduces the risk of the thyristor Q1 being broken down.

[0037] The first relay K1 is model AHES4191, the second relay K2 is model HFE10-1 / 12-HST-L2, the thyristor Q1 is model BTA440Z-800BTQ, and the output optocoupler U1 is model MOC3083SR2M.

[0038] Pin 1 of the output optocoupler U1, pin 5 of the first relay K1, and pin 5 of the second relay K2 are respectively connected to a power supply, which is VCC-12V.

[0039] The power consumption of the load R4 is 7KW.

[0040] The resistance of the first resistor R1 is 1KΩ, and the resistance of the second resistor R2 and the third resistor R3 are both 360Ω.

[0041] Working principle: When the charging station starts charging, after plugging in the charging gun, the vehicle and the charging station are ready to start charging. The first control signal CTR1 is triggered to activate the first relay K1, and the second relay K2 is triggered to activate the output optocoupler U1. The activation of the output optocoupler U1 then controls the thyristor Q1 to conduct and supply power to the subsequent stage. Since the output optocoupler U1 has a zero-crossing trigger function, it ensures that the thyristor Q1 is closed at the zero voltage point. Finally, the third control signal CTR3 and the fourth control signal CTR4 are triggered to activate the second relay K2, and the charging pile starts charging. The second relay K2 is connected in parallel with the thyristor Q1, and the second relay K2 is connected in series with a 7KW load R4, thereby realizing the parallel current shunting of the thyristor Q1 and reducing the heat loss of the thyristor Q1. Since the output optocoupler U1 is a silicon controlled rectifier optocoupler with a zero-crossing trigger function, and the combination of the output optocoupler U1 and the thyristor Q1 can ensure that the first relay K1 is activated at zero voltage, thereby avoiding the phenomenon of arcing and sticking of the first relay K1 when it is activated.

[0042] After the charging pile finishes charging, the second relay K2 is disconnected by triggering the third control signal CTR3 and the fourth control signal CTR4. The second relay K2 stops the output optocoupler U1 from operating. The stopping of the output optocoupler U1 then controls the thyristor Q1 to disconnect. Since the output optocoupler U1 has a zero-crossing trigger function, it ensures that the thyristor Q1 disconnects at the zero voltage point. Finally, the first relay K1 is disconnected by triggering the first control signal CTR1. Then the charging gun is unplugged. Since the output optocoupler U1 is a thyristor optocoupler with a zero-crossing trigger function, and the combination of the output optocoupler U1 and the thyristor Q1 can ensure that the first relay K1 disconnects at zero voltage, it avoids the phenomenon of arcing and sticking when the first relay K1 is disconnected.

[0043] The composite switch control circuit of the charging pile relay is applied to the charging pile, which not only improves the life of the main relay in the charging pile circuit, but also ensures the safety of the charging process, reduces the replacement cost of the relay in the charging pile circuit, and makes the overall circuit more stable.

[0044] Furthermore, the second relay K2 is a magnetic latching relay of model HFE10-1 / 12-HST-L2, which has a holding function. Once set or reset, the relay remains in its original state even if the coil is de-energized. Its normally closed or normally open state depends entirely on the action of the permanent magnet. The switching state transition is triggered by a pulse electrical signal of a certain width. When using the HFE10-1 / 12-HST-L2 relay, ensure that the excitation voltage applied to the coil reaches the rated voltage and that the pulse width is greater than 5 times the action or reset time. Do not apply voltage to the action coil and the reset coil at the same time, and do not apply voltage to the coil for a long time (more than 1 minute).

[0045] Furthermore, the thyristor Q1 is a bidirectional thyristor with the model number BTA440Z-800BTQ. The BTA440Z-800BTQ thyristor is a high-performance bidirectional thyristor, which is particularly suitable for switching and controlling high voltage and high current loads, and has high off-state voltage and on-state current capabilities.

[0046] Furthermore, the output optocoupler U1 adopts the MOC3083SR2M optocoupler, which realizes the isolation and control between the logic circuit and the power supply circuit through optocoupler, switches at zero voltage point, reduces conducted and radiated line noise, and can work normally in the temperature range of -40°C to +85°C.

[0047] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this utility model without departing from the spirit and scope of this utility model. Any modifications or equivalent substitutions should be covered within the protection scope of the claims of this utility model.

Claims

1. A composite switch control circuit for a charging post relay, characterized in that, The first relay K1, the second relay K2, the thyristor Q1 and the output optocoupler U1 are included, the first relay K1 is connected with the second relay K2 in series, the second relay K2 is connected with the thyristor Q1 in parallel, and the thyristor Q1 is connected with the output optocoupler U1 in parallel.

2. The composite switch control circuit of a charging pile relay according to claim 1, characterized in that, The thyristor Q1 is a bidirectional thyristor, a third resistor R3 is connected between the G electrode and the main electrode T1 of the bidirectional thyristor, and the bidirectional thyristor is connected with the output optocoupler U1 in series through the second resistor R2 and the main electrode T2.

3. The composite switch control circuit for a charging pile relay as described in claim 2, characterized in that, The output optocoupler U1 is a silicon controlled output optocoupler, the pin 2 of the output optocoupler U1 is connected with the second control signal CTR2 through the first resistor R1, and the pin 4 and the pin 6 of the output optocoupler U1 are connected with the thyristor Q1 in series.

4. The composite switch control circuit of claim 1, wherein, The pin 2 and the pin 1 of the first relay K1 are connected with the live wire and the zero line respectively, and the pin 4 of the first relay K1 is connected with the first control signal CTR1.

5. The composite switch control circuit for a charging pile relay as described in claim 1, characterized in that, The second relay K2 is a magnetic latching relay, the pin 4 of the second relay K2 is connected with the first relay K1, the pin 3 of the second relay K2 is connected with the thyristor Q1, and the pin 1 and the pin 2 of the second relay K2 are connected with the third control signal CTR3 and the fourth control signal CTR4 respectively.

6. The composite switch control circuit of a charging station relay according to claim 1, wherein, The second relay K2 is connected with the load R4 in series.

7. The composite switch control circuit of a charging station relay according to claim 1, wherein, The model of the first relay K1 is AHES4191, the model of the second relay K2 is HFE10-1 / 12-HST-L2, the model of the thyristor Q1 is BTA440Z-800BTQ, and the model of the output optocoupler U1 is MOC3083SR2M.

8. The composite switch control circuit of a charging station relay according to claim 1, wherein, The pin 1 of the output optocoupler U1, the pin 5 of the first relay K1 and the pin 5 of the second relay K2 are connected with the power supply respectively, and the power supply is VCC-12V.

9. The composite switch control circuit of claim 6, wherein, The power consumption of the load R4 is 7KW.

10. The composite switch control circuit of claim 3, wherein, The resistance value of the first resistor R1 is 1KΩ, and the resistance values of the second resistor R2 and the third resistor R3 are both 360Ω.

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