Dual power supply fast switching circuit and switching method thereof

Abstract

This invention relates to a dual-power fast switching circuit and its switching method. It includes a single-pole double-throw relay K1, optocouplers U1 and U2, IGBT transistors GB1 and GB2, TVS diodes D9 and D10, transistor Q1, multiple rectifier diodes, and multiple resistors. A control signal from the control unit is connected to the base of transistor Q1 via resistor R5. The drain of transistor Q1 is grounded. The collector is connected in parallel to one side of pin 2 of the relay K1 coil and the positive terminal of one pin of diode D11. The coil of relay K1 is connected in parallel to the negative terminal of pin 2 of diode D11, and then connected to pin 2 of optocoupler U1. Pin 1 of optocoupler U1 is connected to pin 2 of optocoupler U2, and pin 1 of optocoupler U2 is connected to the control power supply. This invention improves the switching speed of dual power supplies, ignores the switching delay of the relays, and is suitable for applications requiring rapid dual-power switching.

Description

Technical Field

[0001] This invention relates to the field of anti-power fluctuation control technology, and in particular to a dual-power fast switching circuit and its switching method. Background Technology

[0002] With the continuous development of the national economy, the requirements for the power system are becoming increasingly higher. The power grid is equipped with a large number of relay protection devices, automatic devices, circuit breakers, and other equipment. In particular, the installation of small-scale distributed power sources in the power consumption system makes the power supply network more complex. As the power grid becomes larger and the number of devices increases, the probability of power grid failures is also higher, easily leading to power outages that affect industrial enterprises and residents' lives. Therefore, most power distribution rooms have adopted dual-power supply systems.

[0003] In the field of anti-power fluctuation, most anti-power fluctuation devices currently use direct relay switching for dual power supply switching. If DC power is used after switching, there are adaptation requirements for the contactor. If AC mains power is used after switching, there are extremely high requirements for the relay's operating time and instantaneous current capacity. Moreover, the relay itself has a mechanical operating time when it operates, and cannot switch at the nanosecond level. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a dual-power fast switching circuit and its switching method, which can suppress the instantaneous inrush current during switching, and the switching time can be on the order of nanoseconds, while maintaining the closure of the entire circuit during the mechanical movement of the contacts when the relay is activated.

[0005] The objective of this invention is achieved as follows: A dual-power fast switching circuit includes a single-pole double-throw relay K1, optocouplers U1 and U2, IGBT transistors GB1 and GB2, TVS diodes D9 and D10, transistor Q1, rectifier diodes D1, D2, D3, R4, D5, D6, D7, D8, D11, and resistors R1, R2, R3, R4, R5; The control signal from the control unit is connected to the base of transistor Q1 via resistor R5. The drain of transistor Q1 is grounded. The collector is connected in parallel to one side of pin 2 of the coil of relay K1 and the positive terminal of one pin of diode D11. After the coil of relay K1 is connected in parallel to the negative terminal of two pins of diode D11, it is connected to pin 2 of optocoupler U1. Pin 1 of optocoupler U1 is connected to pin 2 of optocoupler U2. Pin 1 of optocoupler U2 is connected to the control power supply. Pin 4 of optocoupler U1 is connected via resistor R1 to pin 2 of IGBT GB1, the negative terminal of diode D1, and the negative terminal of diode D7, respectively. Pin 6 of optocoupler U1 is connected to two paths: one path is connected to one end of resistor R2, and the other path is connected to pin 1 of IGBT GB1. Pin 3 of IGBT GB1 is connected via TVS diode D9 and the other end of resistor R2 to the positive terminals of diodes D8 and D2. Pin 2 of diode D8 and pin 1 of diode D1 are connected to the second power supply AC2L. Pin 2 of diode D2 and pin 1 of diode D7 are connected to the power output point OutL, which is connected to one side of the external load. Pin 4 of optocoupler U2 is connected to pin 2 of IGBT GB2, the negative terminal of diode D5, and the negative terminal of diode D3 via resistor R3. Pin 6 of optocoupler U2 is connected to two paths: one path is connected to one end of resistor R4, and the other path is connected to pin 1 of IGBT GB2. Pin 3 of IGBT GB2 is connected to the positive terminals of diodes D4 and D6 via TVS diode D10 and the other end of resistor R4. Pin 2 of diode D4 and pin 1 of diode D5 are connected to the second power supply AC2N. Pin 2 of diode D6 and pin 1 of diode D3 are connected to the power output point OutN, which is connected to the other side of the external load.

[0006] Furthermore, a set of normally closed contact pins 3 and 8 of the relay K1 are connected to the live and neutral wires of the first power supply.

[0007] Furthermore, pins 4 and 7 of the relay K1 are connected to the load.

[0008] Furthermore, the normally open contact pins 5 and 6 of the relay K1 are connected to the live and neutral wires of the second power supply.

[0009] A switching method for a dual-power supply fast switching circuit includes the following: When CPU-DO is low, transistor Q1 is not conducting, and the circuits of VCC, optocouplers U1 and U2, relay K1, transistor Q1, and GND are closed. Relay K1 does not operate, and the live and neutral wires of the first power supply are used. When CPU-DO is high, transistor Q1 is turned on, and the circuit of VCC, optocouplers U1 and U2, relay K1, transistor Q1 and GND is opened. Relay K1 is energized, and the contacts have not yet switched to normally open contacts. Optocouplers U1 and U2 are turned on, and the power supply circuit of the second set of power supplies is turned on using the secondary path of U1 and U2. Secondary paths for optocouplers U1 and U2: When the AC2L voltage is higher than the AC2N voltage, the circuit diode D1, resistor R1, secondary circuit of optocoupler U1, resistor R2, diode D2, load, diode D3, resistor R3, secondary circuit of optocoupler U2, resistor R4, and diode D4 form a voltage path. The voltage division across resistors R2 and R4 causes IGBTs GB1 and GB2 to be in working state. AC2L, diode D1, IGBT GB1, TVS diode D9, diode D2, load, diode D3, IGBT GB2, TVS diode D10, diode D4, and AC2N form a circuit. When the AC2L voltage is lower than the AC2N voltage, the circuit diode D5, resistor R3, secondary circuit of optocoupler U2, resistor R4, diode D6, load, diode D7, resistor R1, secondary circuit of optocoupler U1, resistor R2, and resistor D8 form a voltage path. The voltage division across resistors R2 and R4 causes IGBTs GB1 and GB2 to be in working state. AC2N, diode D5, IGBT GB2, TVS diode D10, diode D6, load, diode D7, IGBT GB1, TVS diode D9, diode D8, and AC2L form a circuit.

[0010] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a dual-power fast switching circuit and its switching method, based on a single-pole double-throw relay, and also includes a circuit composed of two optocouplers, two IGBTs, two TVS diodes, a rectifier diode, a transistor, and multiple resistors. It can improve the switching speed of dual power supplies, ignore the switching action delay of the relay, and is suitable for occasions requiring fast switching of dual power supplies. It can suppress the instantaneous inrush current during switching, and the switching time can be on the order of nanoseconds. It maintains the closure of the entire circuit during the mechanical movement of the contacts when the relay is activated. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of the present invention. Implementation

[0012] To better understand the technical solution of the present invention, a detailed description will be provided below in conjunction with relevant illustrations. It should be understood that the specific embodiments described below are not intended to limit the specific implementation of the technical solution of the present invention, but are merely possible implementations of the technical solution of the present invention. It should be noted that the descriptions of the positional relationships of the components herein, such as component A being located above component B, are based on the relative positions of the components in the illustrations and are not intended to limit the actual positional relationships of the components. Example 1

[0013] See Figure 1 , Figure 1A schematic diagram of the structure of the present invention has been drawn. As shown in the figure, the present invention relates to a dual-power fast switching circuit, which includes a single-pole double-throw relay K1, optocouplers U1 and U2, IGBT transistors GB1 and GB2, TVS diodes D9 and D10, transistor Q1, rectifier diodes D1, D2, D3, D4, D5, D6, D7, D8, D11, and resistors R1, R2, R3, R4, and R5.

[0014] The control signal "CPU-DO" from the control unit is connected to the base of transistor Q1 via resistor R5. The drain of transistor Q1 is grounded. The collector is connected in parallel to one side of pin 2 of the coil of relay K1 and the positive terminal of one pin of diode D11. The coil of relay K1 is connected in parallel to the negative terminal of pin 2 of diode D11, and then connected to pin 2 of optocoupler U1. Pin 1 of optocoupler U1 is connected to pin 2 of optocoupler U2. Pin 1 of optocoupler U2 is connected to the control power supply Vcc.

[0015] Pin 4 of optocoupler U1 is connected to pin 2 of IGBT GB1, pin 2 of diode D1, and pin 2 (negative terminal) of diode D7 via resistor R1. Pin 6 of optocoupler U1 is connected to two paths: one path is connected to one end of resistor R2, and the other path is connected to pin 1 of IGBT GB1. Pin 3 of IGBT GB1 is connected to pin 1 (positive terminal) of diodes D8 and D2 via TVS diode D9 and the other end of resistor R2. Pin 2 of diode D8 and pin 1 of diode D1 are connected to the second power supply AC2L. Pin 2 of diode D2 and pin 1 of diode D7 are connected to the power output point OutL, which is connected to the side of the external load.

[0016] Pin 4 of optocoupler U2 is connected via resistor R3 to pin 2 of IGBT GB2, pin 2 of diode D5, and pin 2 (negative terminal) of diode D3. Pin 6 of optocoupler U2 is connected to two paths: one path is connected to one end of resistor R4, and the other path is connected to pin 1 of IGBT GB2. Pin 3 of IGBT GB2 is connected via TVS diode D10 and the other end of resistor R4 to pin 1 (positive terminal) of diodes D4 and D6. Pin 2 of diode D4 and pin 1 of diode D5 are connected to the second power supply AC2N. Pin 2 of diode D6 and pin 1 of diode D3 are connected to the power output point OutN, which is connected to the other side of the external load.

[0017] Relay K1 has a set of normally closed contacts, pins 3 and 8, connected to the live and neutral wires (AC1N and AC1L) of the first power supply. Pins 4 and 7 are connected to the load (OutN and OutL). Normally open contacts, pins 5 and 6, are connected to the live and neutral wires (AC2N and AC2L) of the second power supply. When the CPU-DO output is low, OutN and OutL output the live and neutral wires of the first power supply. When the CPU-DO output is high, OutN and OutL output the live and neutral wires of the second power supply.

[0018] The present invention relates to a switching method for a dual-power supply fast switching circuit, comprising the following: 1. When CPU-DO is low, transistor Q1 is not conducting, and the circuits of VCC, optocouplers U1 and U2, relay K1, transistor Q1 and GND are closed. Relay K1 does not operate, and the live and neutral wires (AC1N and AC1L) of the first power supply are used. 2. When CPU-DO is high, transistor Q1 is turned on, and the circuit of VCC, optocouplers U1 and U2, relay K1, transistor Q1 and GND is opened. Relay K1 is energized, but the contacts have not yet switched to normally open contacts. Optocouplers U1 and U2 are turned on, and the power supply circuit of the second set of power supplies is turned on using the secondary path of U1 and U2.

[0019] 3. Secondary paths of optocouplers U1 and U2; 3.1 When the AC2L voltage is higher than the AC2N voltage, the circuit diode D1, resistor R1, the secondary circuit of optocoupler U1, resistor R2, diode D2, load, diode D3, resistor R3, the secondary circuit of optocoupler U2, resistor R4, and diode D4 form a voltage path. The voltage division across resistors R2 and R4 causes IGBTs GB1 and GB2 to be in working state. AC2L, diode D1, IGBT GB1, TVS diode D9, diode D2, load, diode D3, IGBT GB2, TVS diode D10, diode D4, and AC2N form a circuit. 3.2 When the AC2L voltage is lower than the AC2N voltage, the circuit diode D5, resistor R3, secondary circuit of optocoupler U2, resistor R4, diode D6, load, diode D7, resistor R1, secondary circuit of optocoupler U1, resistor R2, and resistor D8 form a voltage path. The voltage division across resistors R2 and R4 causes IGBTs GB1 and GB2 to be in working state. AC2N, diode D5, IGBT GB2, TVS diode D10, diode D6, load, diode D7, IGBT GB1, TVS diode D9, diode D8, and AC2L form a circuit.

[0020] The above are merely specific application examples of the present invention and do not constitute any limitation on the scope of protection of the present invention. All technical solutions formed by equivalent transformations or substitutions fall within the scope of protection of the present invention.

Claims

1. A dual-power supply fast switching circuit, characterized in that: It includes a single-pole double-throw relay K1, optocouplers U1 and U2, IGBT transistors GB1 and GB2, TVS diodes D9 and D10, transistor Q1, rectifier diodes D1, D2, D3, D4, D5, D6, D7, D8, D11, and resistors R1, R2, R3, R4, R5; The control signal from the control unit is connected to the base of transistor Q1 via resistor R5. The drain of transistor Q1 is grounded. The collector is connected in parallel to one side of pin 2 of the coil of relay K1 and the positive terminal of one pin of diode D11. After the coil of relay K1 is connected in parallel to the negative terminal of two pins of diode D11, it is connected to pin 2 of optocoupler U1. Pin 1 of optocoupler U1 is connected to pin 2 of optocoupler U2. Pin 1 of optocoupler U2 is connected to the control power supply. Pin 4 of optocoupler U1 is connected via resistor R1 to pin 2 of IGBT GB1, the negative terminal of diode D1, and the negative terminal of diode D7, respectively. Pin 6 of optocoupler U1 is connected to two paths: one path is connected to one end of resistor R2, and the other path is connected to pin 1 of IGBT GB1. Pin 3 of IGBT GB1 is connected via TVS diode D9 and the other end of resistor R2 to the positive terminals of diodes D8 and D2. Pin 2 of diode D8 and pin 1 of diode D1 are connected to the second power supply AC2L. Pin 2 of diode D2 and pin 1 of diode D7 are connected to the power output point OutL, which is connected to one side of the external load. Pin 4 of optocoupler U2 is connected to pin 2 of IGBT GB2, the negative terminal of diode D5, and the negative terminal of diode D3 via resistor R3. Pin 6 of optocoupler U2 is connected to two paths: one path is connected to one end of resistor R4, and the other path is connected to pin 1 of IGBT GB2. Pin 3 of IGBT GB2 is connected to the positive terminals of diodes D4 and D6 via TVS diode D10 and the other end of resistor R4. Pin 2 of diode D4 and pin 1 of diode D5 are connected to the second power supply AC2N. Pin 2 of diode D6 and pin 1 of diode D3 are connected to the power output point OutN, which is connected to the other side of the external load.

2. The dual-power fast switching circuit according to claim 1, characterized in that: A set of normally closed contacts, pins 3 and 8, of the relay K1 are connected to the live and neutral wires of the first power supply.

3. The dual power supply fast switching circuit according to claim 1, characterized in that: The relay K1 has pins 4 and 7 connected to the load.

4. The dual-power fast switching circuit according to claim 1, characterized in that: The normally open contacts 5 and 6 of the relay K1 are connected to the live and neutral wires of the second power supply.

5. A switching method for the dual-power fast switching circuit as described in claim 1, characterized in that, Includes the following: When CPU-DO is low, transistor Q1 is not conducting, and the circuits of VCC, optocouplers U1 and U2, relay K1, transistor Q1, and GND are closed. Relay K1 does not operate, and the live and neutral wires of the first power supply are used. When CPU-DO is high, transistor Q1 is turned on, and the circuit of VCC, optocouplers U1 and U2, relay K1, transistor Q1 and GND is opened. Relay K1 is energized, and the contacts have not yet switched to normally open contacts. Optocouplers U1 and U2 are turned on, and the power supply circuit of the second set of power supplies is turned on using the secondary path of U1 and U2. Secondary paths for optocouplers U1 and U2: When the AC2L voltage is higher than the AC2N voltage, the circuit diode D1, resistor R1, secondary circuit of optocoupler U1, resistor R2, diode D2, load, diode D3, resistor R3, secondary circuit of optocoupler U2, resistor R4, and diode D4 form a voltage path. The voltage division across resistors R2 and R4 causes IGBTs GB1 and GB2 to be in working state. AC2L, diode D1, IGBT GB1, TVS diode D9, diode D2, load, diode D3, IGBT GB2, TVS diode D10, diode D4, and AC2N form a circuit. When the AC2L voltage is lower than the AC2N voltage, the circuit diode D5, resistor R3, secondary circuit of optocoupler U2, resistor R4, diode D6, load, diode D7, resistor R1, secondary circuit of optocoupler U1, resistor R2, and resistor D8 form a voltage path. The voltage division across resistors R2 and R4 causes IGBTs GB1 and GB2 to be in working state. AC2N, diode D5, IGBT GB2, TVS diode D10, diode D6, load, diode D7, IGBT GB1, TVS diode D9, diode D8, and AC2L form a circuit.

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