Control panel for high voltage direct current contactor

Abstract

The utility model relates to a control panel for high voltage direct current contactor for controlling the on-off of contactor coil current in direct current contactor, including power input circuit, PWM square wave generating circuit, switching circuit and switch drive circuit, the contactor coil with the switching circuit is in series between the positive and negative pole of power, the power input circuit provides the working power supply for direct current contactor coil and PWM square wave generating circuit, the PWM square wave generating circuit generates square wave signal, and the on-off of current in the contactor coil is controlled through the switch drive circuit and the switching circuit, and the duty cycle of the PWM square wave signal generated by the PWM square wave generating circuit is adjusted to reach the purpose of reducing the power consumption of direct current contactor, makes direct current contactor maintain the attraction state under the action of smaller current, prevents direct current contactor from causing heat generation due to excessive current, and guarantees the service life of direct current contactor.

Description

Technical Field

[0001] This utility model relates to the field of DC contactor control technology, specifically to a control board for a high-voltage DC contactor. Background Technology

[0002] High-voltage DC contactors are an important component of power systems, widely used in the control and switching of various DC power sources. Their main function is to connect or disconnect DC circuits when needed, thereby achieving control and protection of the power system.

[0003] A high-voltage DC contactor mainly consists of an electromagnet, contacts, and springs. The electromagnet is the control part of the contactor, which uses electromagnetic action to close and open the contacts. The contacts are the actuating part of the contactor, directly participating in the connection and disconnection of the circuit. The springs are used to ensure the stability and reliability of the contacts when they are closed and opened.

[0004] High-voltage DC contactors are high-voltage, high-current switching control devices used in DC circuits. They are widely used in the new energy industry, such as charging piles, electric vehicles, photovoltaic power generation, and energy storage cabinets. High-voltage DC contactors control the switching by the engagement and disengagement of their internal coils. Most current DC contactors are powered by DC power supplies, using a fixed rated voltage. Using higher voltages to control DC contactors can easily cause severe overheating, reducing their lifespan. Utility Model Content

[0005] In view of this, it is necessary to provide a control board for a high-voltage DC contactor that controls and maintains the contactor coil engagement by PWM square wave control.

[0006] A control board for a high-voltage DC contactor, used to control the on / off state of the contactor coil current in the DC contactor, includes a power input circuit, a PWM square wave generation circuit, a switching circuit, and a switch driving circuit. The contactor coil and the switching circuit are connected in series between the positive and negative terminals of the power supply. The output terminal of the power input circuit is connected to the PWM square wave generation circuit, and the output terminal of the PWM square wave generation circuit is connected to the switch driving circuit. The PWM square wave signal output by the PWM square wave generation circuit drives the switching circuit to switch on and off via the switch driving circuit, thereby controlling the opening and closing of the contacts in the DC contactor by controlling the on / off state of the current in the contactor coil.

[0007] Preferably, the power input circuit includes an LC filter circuit and a linear regulator chip U2. The LC filter circuit includes a first inductor L1, a second inductor L2, and a seventh capacitor C7. One end of the first inductor L1 and the second inductor L2 are respectively connected to the positive and negative input terminals V+ / V- of the power input circuit, and the other end is respectively connected to the two ends of the seventh capacitor C7. The midpoint of the first inductor L1 and the seventh capacitor C7 is connected to the positive terminal of the contactor coil through a fourth diode D4. The midpoint of the first inductor L1 and the seventh capacitor C7 is also connected to the linear regulator chip U2 through an eighth diode D8.

[0008] Preferably, the input pin IN of the linear regulator chip U2 is connected to the cathode of the eighth diode D8, the output pin OUT of the linear regulator chip U2 is connected to the input terminal of the PWM square wave generation circuit, and the ground pin GND of the linear regulator chip U2 is grounded; a first Zener diode D1, a fifth capacitor C5, and a third capacitor C3 are connected in parallel between the input pin IN and the ground pin GND of the linear regulator chip U2; a first capacitor C1 and a seventh resistor R7 are connected in series between the output pin OUT and the ground pin GND of the linear regulator chip U2.

[0009] Preferably, the PWM square wave generation circuit includes a PWM generator chip U1, the power supply pin VDD of the PWM generator chip U1 is connected to the output pin OUT of the linear regulator chip U2, the sampling signal input pin PB7 of the PWM generator chip U1 is connected to the cathode of the eighth diode D8 through the fifth resistor R5, and the PWM signal output pin PA4 of the PWM generator chip U1 is connected to the switch drive circuit.

[0010] Preferably, the switching circuit includes a second switching transistor Q1B connected in series, the source of the first switching transistor Q1A is connected to the drain of the second switching transistor Q1B, the drain of the first switching transistor Q1A is connected to the negative terminal of the contactor coil, and the source of the second switching transistor Q1B is grounded.

[0011] Preferably, the switch driving circuit includes a first switch driving circuit and a second switch driving circuit, wherein the first switch driving circuit is connected to the gate of the first switch transistor Q1A and the second switch driving circuit is connected to the gate of the second switch transistor Q1B.

[0012] Preferably, the first switch driving circuit includes a third Zener diode D3, a sixth Zener diode D6, a first resistor R1, a fourth resistor R4, and a sixth capacitor C6; the gate of the first switch Q1A is connected to the output terminal of the power input circuit through the first resistor R1 and the third Zener diode D3; the sixth Zener diode D6, the fourth resistor R4, and the sixth capacitor C6 are connected in parallel between the gate and the source of the first switch Q1A; a second diode D2 is connected between the source of the first switch Q1A and the output terminal of the power input circuit to prevent reverse connection of the power supply on the contactor coil.

[0013] Preferably, the second switch driving circuit includes a second resistor R2 and a seventh diode D7, and the gate of the second switch Q1B is connected to the output terminal of the PWM square wave generation circuit through the second resistor R2 and the seventh diode D7 connected in parallel.

[0014] In the control board for the aforementioned high-voltage DC contactor, the power input circuit provides operating power to the DC contactor coil and the PWM square wave generation circuit. The PWM square wave generation circuit generates a square wave signal, which controls the on / off state of the current in the contactor coil through the switch drive circuit and the switch circuit. By adjusting the duty cycle of the PWM square wave signal generated by the PWM square wave generation circuit, the power consumption of the DC contactor is reduced, allowing the DC contactor to maintain its engaged state under a smaller current, preventing overheating due to excessive current, and ensuring the service life of the DC contactor. Simultaneously, the DC contactor can operate in a low-power state for extended periods, saving energy and reducing electromagnetic interference to the external environment. This invention features a simple circuit structure, is easy to implement, has low cost, and is readily applicable. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the circuit structure of the control board for the high-voltage DC contactor according to an embodiment of the present invention.

[0016] Figure 2 This is a circuit diagram of the control board for a high-voltage DC contactor according to an embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram of the power input circuit, switching circuit, and switch drive circuit of the control board for the high-voltage DC contactor according to an embodiment of the present invention.

[0018] Figure 4 This is a schematic diagram of the power input circuit of the control board for a high-voltage DC contactor according to an embodiment of the present invention.

[0019] Figure 5This is a schematic diagram of the PWM square wave generation circuit of the control board for a high-voltage DC contactor according to an embodiment of this utility model. Detailed Implementation

[0020] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0021] Please see Figure 1 and Figure 2 This paper illustrates a control board for a high-voltage DC contactor, comprising a power input circuit, a PWM square wave generation circuit, a switching circuit, and a switch driving circuit. The contactor coil and the switching circuit are connected in series between the positive and negative terminals of the power supply. The output terminal of the power input circuit is connected to the PWM square wave generation circuit, and the output terminal of the PWM square wave generation circuit is connected to the switch driving circuit. The PWM square wave signal output by the PWM square wave generation circuit drives the switching circuit to switch on and off via the switch driving circuit, thereby controlling the opening and closing of the contacts in the DC contactor by switching the current in the contactor coil on and off.

[0022] Preferably, please refer to Figure 3 The diagram illustrates the power input circuit, switching circuit, and switching drive circuit in this embodiment. The power input circuit includes an LC filter circuit and a linear regulator chip U2. The LC filter circuit includes a first inductor L1, a second inductor L2, and a seventh capacitor C7. One end of the first inductor L1 and the second inductor L2 are respectively connected to the positive and negative input terminals V+ / V- of the power input circuit, and the other end is respectively connected to the two ends of the seventh capacitor C7. The midpoint of the first inductor L1 and the seventh capacitor C7 is connected to the positive terminal of the contactor coil through a fourth diode D4. The midpoint of the first inductor L1 and the seventh capacitor C7 is also connected to the linear regulator chip U2 through an eighth diode D8.

[0023] Specifically, the anodes of the fourth diode D4 and the eighth diode D8 are respectively connected to the positive input terminal V+ of the power input circuit through the first inductor L1, and the fourth diode D4 and the eighth diode D8 serve to prevent reverse connection.

[0024] Specifically, it also includes an eighth capacitor, the two ends of which are connected to the cathode of the fourth diode D4, the midpoint of the second inductor L2 and the fourth capacitor C7, respectively.

[0025] Preferably, please refer to Figure 4The diagram shows the linear regulator chip U2 in the power input circuit of this embodiment. The input pin IN of the linear regulator chip U2 is connected to the cathode of the eighth diode D8, and the output pin OUT of the linear regulator chip U2 is connected to the input terminal of the PWM square wave generation circuit. The ground pin GND of the linear regulator chip U2 is grounded. A first Zener diode D1, a fifth capacitor C5, and a third capacitor C3 are connected in parallel between the input pin IN and the ground pin GND of the linear regulator chip U2. A first capacitor C1 and a seventh resistor R7 are connected in series between the output pin OUT and the ground pin GND of the linear regulator chip U2.

[0026] Specifically, the linear regulator chip U2 is preferably an SE86750K1 chip. In this embodiment, the voltage regulation value of the first Zener diode D1 is 36V, so that the upper limit of the input voltage of the linear regulator chip U2 is 36V, and the output voltage of the linear regulator chip U2 is 5V, which is used as the power supply for the PWM square wave generation circuit.

[0027] The power input circuit provides a wider range of applicable power supply voltages, from 9V to 36V.

[0028] Preferably, please refer to Figure 5 The diagram illustrates the PWM square wave generation circuit in this embodiment. The PWM square wave generation circuit includes a PWM generator chip U1. The power supply pin VDD of the PWM generator chip U1 is connected to the output pin OUT of the linear regulator chip U2. The sampling signal input pin PB7 of the PWM generator chip U1 is connected to the cathode of the eighth diode D8 through the fifth resistor R5. The PWM signal output pin PA4 of the PWM generator chip U1 is connected to the switch drive circuit.

[0029] Specifically, the PB7 pin of the PWM generator chip U1 is also connected to a fifth Zener diode D5, a third resistor R3, and a fourth capacitor C4 in parallel. The fifth resistor R5 and the third resistor R3 form a voltage sampling circuit, and the fourth capacitor C4 serves as a filter.

[0030] Specifically, the PB7 pin of the PWM generator chip U1 is used for power supply voltage sampling, feeding back the input voltage value of the power input circuit to the PWM generator chip U1. The PWM generator chip U1 controls the duty cycle of the output PWM square wave signal based on the input voltage value fed back from the PB7 pin, thereby automatically adjusting the duty cycle of the PWM square wave signal through the external operating voltage, thus achieving the purpose of regulating the contactor coil current.

[0031] Preferably, please refer to Figure 3The switching circuit includes a second switching transistor Q1B connected in series. The source of the first switching transistor Q1A is connected to the drain of the second switching transistor Q1B. The drain of the first switching transistor Q1A is connected to the negative terminal of the contactor coil. The source of the second switching transistor Q1B is grounded.

[0032] Preferably, the switch driving circuit includes a first switch driving circuit and a second switch driving circuit, wherein the first switch driving circuit is connected to the gate of the first switch transistor Q1A and the second switch driving circuit is connected to the gate of the second switch transistor Q1B.

[0033] Preferably, the first switch driving circuit includes a third Zener diode D3, a sixth Zener diode D6, a first resistor R1, a fourth resistor R4, and a sixth capacitor C6; the gate of the first switch Q1A is connected to the output terminal of the power input circuit through the first resistor R1 and the third Zener diode D3; the sixth Zener diode D6, the fourth resistor R4, and the sixth capacitor C6 are connected in parallel between the gate and the source of the first switch Q1A; a second diode D2 is connected between the source of the first switch Q1A and the output terminal of the power input circuit to prevent reverse connection of the power supply on the contactor coil.

[0034] Specifically, the first resistor R1 and the fourth resistor R4 form a power supply voltage divider circuit, which gives the gate of the first switch Q1A a forward bias voltage. When the voltage output from the power input circuit to the switch circuit is normal, the first switch Q1A is turned on.

[0035] Preferably, the second switch driving circuit includes a second resistor R2 and a seventh diode D7, and the gate of the second switch Q1B is connected to the output terminal of the PWM square wave generation circuit through the second resistor R2 and the seventh diode D7 connected in parallel.

[0036] Specifically, the PWM signal output pin PA4 of the PWM generator chip U1 is connected to the second switch drive circuit. The output PWM square wave signal controls the conduction and disconnection of the second switch transistor Q1B, thereby controlling the current flow in the contactor coil.

[0037] Specifically, in this embodiment, the linear regulator chip U2 uses the SE8650K1 chip to broaden the range of power supply voltage, thus making it easier for users to select the voltage of the switching power supply; the PWM generator chip U1 uses the PMS132B chip, which outputs for 10-15 milliseconds with a duty cycle of 90-95% at the moment of power-on to meet the pull-in condition, then adjusts the duty cycle to about 85% for a buffer of 20 milliseconds, and finally locks it between 2W and 3W. According to the customer's requirements, it meets the requirements of energy saving and reliability, thereby ensuring that the energy-saving board is in a wide voltage range, low power consumption, energy saving and environmental protection, and safe and reliable operation for a long time.

[0038] Specifically, using the energy-saving control board in this technical solution has four major advantages:

[0039] 1. Wide applicable voltage range: 9~36V, facilitating voltage selection;

[0040] 2. Reduce power consumption to approximately 2W to maintain operation;

[0041] 3. Energy-saving and environmentally friendly, it operates in a low-power state for extended periods, saving energy and reducing electromagnetic interference to the environment;

[0042] 4. Safe and reliable, low power consumption greatly reduces coil heating and extends coil life.

[0043] It should be noted that this utility model is not limited to the above-described embodiments. Based on the inventive spirit of this utility model, those skilled in the art can make other changes, and these changes made based on the inventive spirit of this utility model should be included within the scope of protection claimed by this utility model.

Claims

1. A control board for a high-voltage DC contactor, used to control the on / off state of the contactor coil current in the DC contactor, characterized in that, The device includes a power input circuit, a PWM square wave generation circuit, a switching circuit, and a switch driving circuit. The contactor coil and the switching circuit are connected in series between the positive and negative terminals of the power supply. The output terminal of the power input circuit is connected to the PWM square wave generation circuit, and the output terminal of the PWM square wave generation circuit is connected to the switch driving circuit. The PWM square wave signal output by the PWM square wave generation circuit drives the switching circuit to open and close via the switch driving circuit, thereby controlling the opening and closing of the contacts in the DC contactor by switching the current in the contactor coil. The switching circuit includes a first switching transistor Q1A and a second switching transistor Q1B connected in series. The source of the first switching transistor Q1A is connected to the drain of the second switching transistor Q1B, the drain of the first switching transistor Q1A is connected to the negative terminal of the contactor coil, and the source of the second switching transistor Q1B is grounded. The switch driving circuit includes a first switch driving circuit and a second switch driving circuit. The first switch driving circuit is connected to the gate of the first switch transistor Q1A, and the second switch driving circuit is connected to the gate of the second switch transistor Q1B.

2. The control board for a high-voltage DC contactor as described in claim 1, characterized in that, The power input circuit includes an LC filter circuit and a linear regulator chip U2. The LC filter circuit includes a first inductor L1, a second inductor L2, and a seventh capacitor C7. One end of the first inductor L1 and the second inductor L2 are respectively connected to the positive and negative input terminals V+ / V- of the power input circuit, and the other end is respectively connected to the two ends of the seventh capacitor C7. The midpoint of the first inductor L1 and the seventh capacitor C7 is connected to the positive terminal of the contactor coil through a fourth diode D4. The midpoint of the first inductor L1 and the seventh capacitor C7 is also connected to the linear regulator chip U2 through an eighth diode D8.

3. The control board for a high-voltage DC contactor as described in claim 2, characterized in that, The input pin IN of the linear regulator chip U2 is connected to the cathode of the eighth diode D8, and the output pin OUT of the linear regulator chip U2 is connected to the input terminal of the PWM square wave generation circuit. The ground pin GND of the linear regulator chip U2 is grounded. The first Zener diode D1, the fifth capacitor C5, and the third capacitor C3 are connected in parallel between the input pin IN and the ground pin GND of the linear regulator chip U2. The first capacitor C1 and the seventh resistor R7 are connected in series between the output pin OUT and the ground pin GND of the linear regulator chip U2.

4. The control board for a high-voltage DC contactor as described in claim 3, characterized in that, The PWM square wave generation circuit includes a PWM generator chip U1. The power supply pin VDD of the PWM generator chip U1 is connected to the output pin OUT of the linear regulator chip U2. The sampling signal input pin PB7 of the PWM generator chip U1 is connected to the cathode of the eighth diode D8 through the fifth resistor R5. The PWM signal output pin PA4 of the PWM generator chip U1 is connected to the switch drive circuit.

5. The control board for a high-voltage DC contactor as described in claim 1, characterized in that, The first switch driving circuit includes a third Zener diode D3, a sixth Zener diode D6, a first resistor R1, a fourth resistor R4, and a sixth capacitor C6; the gate of the first switch Q1A is connected to the output terminal of the power input circuit through the first resistor R1 and the third Zener diode D3; the sixth Zener diode D6, the fourth resistor R4, and the sixth capacitor C6 are connected in parallel between the gate and the source of the first switch Q1A; a second diode D2 is connected between the source of the first switch Q1A and the output terminal of the power input circuit to prevent reverse connection of the power supply on the contactor coil.

6. The control board for a high-voltage DC contactor as described in claim 1, characterized in that, The second switch driving circuit includes a second resistor R2 and a seventh diode D7. The gate of the second switch Q1B is connected to the output terminal of the PWM square wave generation circuit through the second resistor R2 and the seventh diode D7 connected in parallel.

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