A thyristor control system and device

Abstract

This application relates to the field of rectifier circuits, and particularly to a thyristor control system and device. A thyristor control system includes a power supply board, an adjustment board, a trigger board, and an isolation board. The power supply board is used to convert the AC voltage into a DC voltage and regulate the voltage to provide power for the adjustment board, the trigger board, and the isolation board. The isolation board is used to isolate the output voltage after rectification by the three-phase bridge fully controlled rectifier circuit and feedback the voltage feedback signal generated after isolation to the adjustment board. The adjustment board is used to receive the given signal and the feedback signal from the isolation board, and adjust the output control signal according to the magnitude of the given signal and the voltage feedback signal. The trigger board is used to provide trigger pulses for the thyristors according to the output control signal from the adjustment board and the synchronization voltage to control the output voltage of the three-phase bridge fully controlled rectifier circuit. This application has the effect of improving the stability of the power system and the energy utilization efficiency.

Description

Technical Field

[0001] The present application relates to the field of rectifier circuits, and in particular, to a thyristor control system and device. Background Art

[0002] Currently, the input power stage of the input rectifier circuit of various power electronic converters generally uses an uncontrolled rectifier or a phase-controlled rectifier circuit. Such rectifier circuits have a simple structure and mature control technology, but the input power factor of the AC side is low, and the rectifier valves at the power transmission end, the inverter valves at the power reception end, and various electronic devices generally require DC power supplies with different voltage levels, and inject a large amount of harmonic current into the power grid. Summary of the Invention

[0003] In order to solve the problems of low power factor and large harmonic current in the input rectifier circuit of the power electronic converter, and improve the stability and energy utilization efficiency of the power system, the present application provides a thyristor control system and device.

[0004] In a first aspect, the present application provides a thyristor control system, adopting the following technical solution:

[0005] A thyristor control system includes a power supply board, an adjustment board, a trigger board, and an isolation board. The power supply board is used to convert the AC voltage into a DC voltage and stabilize it, and provide power for the adjustment board, the trigger board, and the isolation board; the isolation board is used to isolate the output voltage after rectification by the three-phase bridge fully controlled rectifier circuit and feedback the voltage feedback signal generated after isolation to the adjustment board; the adjustment board is used to receive the given signal and the feedback signal of the isolation board, and adjust the output control signal according to the magnitude of the given signal and the voltage feedback signal; the trigger board is used to provide trigger pulses for the thyristors according to the output control signal output by the adjustment board and the synchronization voltage to control the output voltage of the three-phase bridge fully controlled rectifier circuit.

[0006] By adopting the above technical solution, the isolation board can isolate the output voltage after rectification and feedback the voltage feedback signal generated after isolation to the adjustment board. The adjustment board adjusts the output control signal according to the magnitude of the given signal and the voltage feedback signal, and at the same time controls the trigger board. The trigger board provides trigger pulses for the thyristors in the three-phase bridge fully controlled rectifier circuit to control the output voltage of the three-phase bridge fully controlled rectifier circuit, making the output voltage approach the given voltage and reducing the harmonic current generated after rectification.

[0007] Optionally, the trigger board includes a trigger unit containing tc787 and six thyristor control units containing capacitors. The thyristor control units are connected to the power supply board. The trigger unit has a phase-shifting voltage input port and six output ports. The thyristor control units are connected to thyristors. The thyristor control units have receiving ports. The output ports of the trigger unit are respectively connected to the receiving ports of the thyristor control units. The thyristor control units control the charging timing of the capacitors in the thyristor control units according to the signals received at the receiving ports to change the trigger pulses.

[0008] By adopting the above technical solution, the trigger unit includes tc787 and can calculate the thyristors connected to the circuit and output modulation pulses through the synchronous voltage and the phase-shifting voltage. After receiving the modulation pulse signal, the thyristor control unit changes the charging timing of the internal capacitor thereof, thereby changing the trigger pulse, and further controlling the conduction angle of the thyristor to change the voltage magnitude.

[0009] Optionally, the isolation board has a voltage feedback control unit, a voltage feedback unit and a proportional reduction unit. The input end of the proportional reduction unit is connected to the output end of the three-phase bridge fully controlled rectifier circuit. The voltage feedback unit has a voltage feedback port. The voltage feedback unit is associated with the proportional reduction unit through a second transformer. The proportional reduction unit proportionally reduces the output voltage to a detection voltage and sends the detection voltage to the induction unit through the second transformer. The induction unit converts the detection voltage into a voltage feedback signal and outputs it from the voltage feedback port. The voltage feedback control unit is electrically connected to the power supply board. At the same time, the voltage feedback control unit is connected to the proportional reduction unit through a first transformer. When the power supply board supplies power to the voltage feedback control unit, the voltage feedback control unit conducts the proportional reduction unit by transmitting voltage through the first transformer and can be associated with the proportional reduction unit through the second transformer.

[0010] By adopting the above technical solution, the isolation board can proportionally reduce the voltage at the output end of the three-phase bridge fully controlled rectifier circuit and convert the proportionally reduced voltage into a voltage signal for feedback to the regulation board, achieving the purpose of isolation feedback.

[0011] Optionally, the regulation board includes a given unit and an integral link unit. The given unit is used to set a given voltage. The given unit is connected to the integral link unit to provide the given voltage. The integral link unit is electrically connected to the power supply board. The integral link unit has a feedback receiving port and a phase-shifting voltage output port. The phase-shifting voltage output port of the integral link unit is connected to the phase-shifting voltage input port of the trigger unit, and the feedback receiving port is connected to the voltage feedback port of the voltage feedback unit.

[0012] By adopting the above technical solution, after receiving the given voltage, the integral link unit calculates a given signal through the given integral link. The given signal combines with the voltage feedback signal to obtain a phase-shifting voltage signal and outputs it from the phase-shifting voltage output port to the trigger unit.

[0013] Optionally, the regulating board further includes a protection unit, which has a phase loss protection port, an overheat protection port, a three-phase current mutual induction port, and an alarm signal output port. The protection unit is connected to the integration link unit, the alarm signal output port is connected to the alarm circuit, the phase loss protection port is connected to the phase loss detection circuit, the overheat protection port is connected to the motor load, and the three-phase current mutual induction port is connected to the current mutual induction circuit. When any one or more of the situations of phase loss, overheat, overcurrent of DC output, and short circuit of DC output occur, the protection unit cuts off the integration link unit, and at the same time, the alarm signal output port of the protection unit transmits a signal.

[0014] By adopting the above technical solution, the protection unit can start to work when the phase loss detection circuit detects phase loss, when the motor load overheats, or when the current mutual induction circuit detects overcurrent of DC output and short circuit of DC output, cut off the integration link unit, and transmit a signal through the alarm signal output port.

[0015] Optionally, the power supply board includes a third transformer, a rectification unit, and a voltage stabilization unit. The rectification unit and the voltage stabilization unit are connected. The voltage stabilization unit has a +15V port, a ground port, a -15V port, and a +24V port. The primary winding of the third transformer is connected to the AC circuit. The rectification unit obtains low-voltage alternating current through the secondary winding of the third transformer and rectifies it into direct current for transmission to the voltage stabilization unit. After voltage stabilization, the voltage stabilization unit outputs direct current through the +15V port, the ground port, the -15V port, and the +24V port.

[0016] By adopting the above technical solution, the third transformer is used to transform high-voltage alternating current into low-voltage alternating current, the rectification unit rectifies the low-voltage alternating current into direct current, and after voltage stabilization by the voltage stabilization unit, it outputs to provide power for the trigger board, the isolation board, and the regulating board.

[0017] In a second aspect, the present application provides a thyristor control device, adopting the following technical solution:

[0018] A thyristor control device includes a three-phase bridge fully controlled rectifier circuit and the above-mentioned thyristor control system. The trigger board is connected to the control poles of the thyristors in the three-phase bridge fully controlled rectifier circuit.

[0019] By adopting the above technical solution, using the thyristor control system to control the thyristors in the three-phase bridge fully controlled rectifier circuit can make the voltage output by the three-phase bridge fully controlled rectifier circuit approach the given value through negative feedback regulation, thereby reducing harmonic current and improving the power factor of the rectifier circuit.

[0020] Optionally, it further includes a rectifier transformer. The primary winding of the rectifier transformer is connected to the AC circuit, the secondary winding of the rectifier transformer is connected to the three-phase bridge fully controlled rectifier circuit, and the rectifier transformer adopts the △ / Y0-11 connection method.

[0021] By adopting the above technical solution, when the rectifier transformer steps down the alternating current, the △ / Y0-11 connection method can reduce the impact on the power grid waveform.

[0022] Optionally, it further includes a fast fuse, and the rectifier transformer is connected to the three-phase bridge fully controlled rectifier circuit through the fast fuse.

[0023] By adopting the above technical solution, since the overload capacity of semiconductor components is very low and they can only withstand a large overload current for a very short time, the fast fuse can quickly blow when a short circuit occurs, playing a role in protecting the thyristor.

[0024] In summary, this application includes at least one of the following beneficial technical effects:

[0025] 1. It can make the voltage output by the three-phase bridge fully controlled rectifier circuit approach the given value through negative feedback regulation, thereby reducing harmonic current and improving the power factor of the rectifier circuit;

[0026] 2. It can quickly cut off the circuit and give an alarm when a phase loss, overheating, short circuit, or overcurrent occurs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of the overall architecture of a thyristor control system provided by an embodiment of this application;

[0028] Figure 2 is a schematic diagram of the principle of a thyristor control device provided by an embodiment of this application;

[0029] Figure 3 is a schematic diagram of the principle of a trigger board provided by an embodiment of this application;

[0030] Figure 4 is a schematic diagram of the principle of an isolation board provided by an embodiment of this application;

[0031] Figure 5 is a schematic diagram of the principle of a given unit provided by an embodiment of this application;

[0032] Figure 6 is a schematic diagram of the principle of an adjustment board provided by an embodiment of this application;

[0033] Figure 7 is a schematic diagram of the principle of an alarm circuit provided by an embodiment of this application;

[0034] Figure 8 is a schematic diagram of the principle of a phase loss detection circuit provided by an embodiment of this application;

[0035] Figure 9 is a schematic diagram of the principle of a power supply board provided by an embodiment of this application.

[0036] Description of reference numerals: 1 - Three - phase bridge fully - controlled rectifier circuit; 2 - Trigger unit; 3 - Thyristor control unit; 4 - Voltage feedback control unit; 5 - Voltage feedback unit; 6 - Scaling - down unit; 7 - Given unit; 8 - Integral - link unit; 9 - Protection unit; 10 - Alarm circuit; 11 - Phase - loss detection circuit; 12 - Current mutual - inductance circuit; 13 - Rectification unit; 14 - Voltage - stabilization unit. Detailed implementation manners

[0037] The following further elaborates on this application Figures 1-9 in conjunction with the attached drawings.

[0038] The embodiment of this application discloses a thyristor control system and a thyristor control device.

[0039] As Figure 1 shown, Figure 1 The overall architecture schematic diagram of the thyristor control system is shown. The thyristor control system includes a power supply board, an adjustment board, a trigger board, and an isolation board. The power supply board is used to convert the AC voltage into a DC voltage and stabilize it, providing power for the adjustment board, the trigger board, and the isolation board; the isolation board is used to isolate the output voltage rectified by the three - phase bridge fully - controlled rectifier circuit 1 and feedback the voltage feedback signal generated after isolation to the adjustment board; the adjustment board is used to receive the given signal and the feedback signal from the isolation board, and adjust the output control signal according to the magnitude of the given signal and the voltage feedback signal; the trigger board is used to provide trigger pulses for the thyristor according to the output control signal output by the adjustment board and the synchronous voltage to control the output voltage of the three - phase bridge fully - controlled rectifier circuit 1.

[0040] The isolation board can isolate the rectified output voltage and feedback the voltage feedback signal generated after isolation to the adjustment board. The adjustment board adjusts the output control signal according to the magnitude of the given signal and the voltage feedback signal, and simultaneously controls the trigger board. The trigger board provides trigger pulses for the thyristors in the three - phase bridge fully - controlled rectifier circuit 1 to control the output voltage of the three - phase bridge fully - controlled rectifier circuit 1, making the output voltage approach the given voltage and reducing the harmonic current generated after rectification.

[0041] As Figure 2 shown, Figure 2The schematic diagram of a thyristor control device is shown. A thyristor control device includes a three-phase bridge fully controlled rectifier circuit 1, a rectifier transformer B5, a fast fuse, and a thyristor control system. The trigger boards in the thyristor control system are respectively connected to the control electrodes of thyristors SCR1 - SCR6 in the three-phase bridge fully controlled rectifier circuit 1. In order to protect the thyristors, a RC series circuit can also be connected in parallel to the thyristors. The primary winding of the rectifier transformer B5 is connected to the AC circuit, and the secondary winding of the rectifier transformer B5 is connected to the three-phase bridge fully controlled rectifier circuit 1 through the fast fuse. Since the overload capacity of semiconductor components is very low and they can only withstand a large overload current for a very short time, the fast fuse can quickly blow when a short circuit occurs, playing a role in protecting the thyristors. The rectifier transformer B5 adopts the △ / Y0 - 11 connection method, and the △ / Y0 - 11 connection method can reduce the impact on the power grid waveform. By using the thyristor control system to control the thyristors in the three-phase bridge fully controlled rectifier circuit 1, the voltage output by the three-phase bridge fully controlled rectifier circuit 1 can be made to approach the given value through negative feedback regulation, thereby reducing harmonic current and improving the power factor of the rectifier circuit.

[0042] As Figure 2 and Figure 3 shown, Figure 3 The schematic diagram of a trigger board provided in this embodiment is shown. The trigger board includes a trigger unit 2 and six thyristor control units 3.

[0043] The trigger unit 2 includes a four-channel operational amplifier LM324N and a phase control circuit tc787. The 3rd contact of the four-channel operational amplifier LM324N, that is, the phase-shifting voltage input port of the trigger unit 2, is used to receive the phase-shifting voltage signal sent by the adjustment board. After being operated by the four-channel operational amplifier LM324N (the operation here is subtraction operation, for example, when the input voltage is 3V, the output voltage is 7V, and when the input voltage is 2V, the output voltage is 2V), it is input to the 4th contact of the phase control circuit tc787. The 18th, 2nd, and 1st contacts of the phase control circuit tc787 are respectively used to receive the synchronous voltage. The 3rd contact and the 17th contact are respectively the GND pole and the VCC pole for power supply. The 5th contact is the output protection inhibition terminal, which can protect the system safety in case of overcurrent and overvoltage. The 6th contact is used to allocate the output mode of the pulse. In this embodiment, the 6th contact is connected to the high level, so the output is in the fully controlled mode. The 12th, 11th, 10th, 9th, 8th, and 7th contacts respectively output double trigger pulses of A, -C; -C, B; B, -A; -A, C; C, -B; and -B, A. Each output contact is connected with a switching diode 1N4148 and is connected to the anode of the switching diode 1N4148. The cathode of each switching diode 1N4148 is respectively connected to the base of TIP122. The emitter of each TIP122 is grounded, and the collector of each TIP122, that is, the output port of the trigger unit 2, is connected to the receiving port of the thyristor control unit 3.

[0044] The thyristor control unit 3 includes a pulse transformer, 1N4007 D100, IN4007 D101, IN4007 D102 and a capacitor C110. Both ends of the capacitor C110 are respectively connected to the control electrode and the cathode of the thyristor. The anode of IN4007 D102, that is, the receiving port of the thyristor control unit 3, is connected to the collector of TIP122. The cathode of IN4007 D102 is connected to the 24V power supply. In order to play a filtering role, the cathode of IN4007 D102 can also be connected to the 24V power supply through an RC parallel circuit. The cathode of IN4007D100 is connected to the anode of IN4007 D101, so that IN4007 D100 and IN4007 D101 are connected in series in the same direction. The series-connected IN4007 D100 and IN4007 D101 are connected in parallel across both ends of the capacitor C110. At the same time, the cathode of IN4007 D101 is connected to the control electrode of the thyristor. IN4007 D102 is connected to IN4007 D100 through the pulse transformer.

[0045] When the output contact of tc787 in the trigger unit 2 outputs, the base of the corresponding TIP122 receives a pulse signal to adjust the opening of the circuit, change the power of the pulse transformer, thereby affecting the charging timing of the capacitor C110, and further changing the trigger pulse to change the conduction angle of the thyristor and control the magnitude of the output voltage.

[0046] As Figure 2 、 Figure 4 shown, Figure 4 Fig. shows the schematic diagram of an isolation board provided in this embodiment. The isolation board includes a first transformer B1, a second transformer B2, a voltage feedback control unit 4, a voltage feedback unit 5 and a proportional reduction unit 6.

[0047] The proportional reduction unit 6 includes 3DK4B T3, 3DK4B T4, a resistor R107, a resistor R108 and a resistor R109. The resistor R107, the resistor R108 and the resistor R109 are connected in series. The series-connected resistor R107, resistor R108 and resistor R109 are the input end of the proportional reduction unit 6 and are connected to the output end of the three-phase bridge fully controlled rectifier circuit 1. A capacitor C2 is connected in parallel at the resistor R108. The reduced voltage is collected from the resistor R108. The high-potential end of the resistor R108 is respectively connected to the collectors of 3DK4B T3 and 3DK4B T4 through the primary winding of the second transformer B2. The emitters of 3DK4B T3 and 3DK4B T4 are respectively connected to the low-potential end of the resistor R108.

[0048] The voltage feedback control unit 4 is electrically connected to the power supply board. The voltage feedback control unit 4 is connected to the proportional reduction unit 6 through the first transformer B1. When the power supply board supplies power to the voltage feedback control unit 4, the voltage feedback control unit 4 transmits a voltage between the base and emitter of 3DK4B T3 and 3DK4B T4 in the proportional reduction unit 6 through the secondary winding of the first transformer B1 to turn them on, enabling the proportional reduction unit 6 to transmit the detected voltage to the voltage feedback unit 5 through the second transformer B2.

[0049] The voltage feedback unit 5 includes a potentiometer W1, a switching diode 1N4148 D5, and a switching diode 1N4148 D6. The anodes of the switching diode 1N4148 D5 and the switching diode 1N4148 D6 are connected through the secondary winding of the second transformer B2. The cathodes of the switching diode 1N4148 D5 and the switching diode 1N4148 D6 are simultaneously connected to the input end of the potentiometer W1. The grounded end of the potentiometer W1 is grounded, and the output end of the potentiometer W1, that is, the voltage feedback port of the voltage feedback unit 5, is used to output a voltage feedback signal.

[0050] As Figure 5 and Figure 6 shown, Figure 5 Figure 1 shows the schematic diagram of a given unit 7 provided in this embodiment. Figure 6 Figure 2 shows the schematic diagram of an adjustment board provided in this embodiment. The adjustment board includes a given unit 7, an integral link unit 8, and a protection unit 9.

[0051] The given unit 7 includes a resistor R112 and a potentiometer W100. The grounded end of the potentiometer W100 is grounded. The input end of the potentiometer W100 is connected to the output contact of the relay KA1 through the resistor R112. The normally open contact of the relay KA1 is connected to the 15V power supply, and the normally closed contact of the relay KA1 is connected to the -15V power supply. The given voltage is set by adjusting the potentiometer W100.

[0052] The integration unit 8 includes four operational amplifiers LM348 and a shorting piece J1. The integration unit 8 has a feedback receiving port and a phase-shifted voltage output port. The 5th contact of the four operational amplifiers LM348 is connected to the output terminal of the potentiometer W100 to receive the given voltage set by the given unit 7. At the same time, the 1st contact of the shorting piece J1 is connected to the output terminal of the potentiometer W100 to receive the given voltage set by the given unit 7. The 9th contact of the four operational amplifiers LM348, that is, the feedback receiving port of the integration unit 8, is connected to the voltage feedback port of the voltage feedback control unit 4. The 8th contact of the four operational amplifiers LM348 is connected to the 3rd contact of the shorting piece J1 to output the phase-shifted voltage after the given integration link and voltage negative feedback regulation. The 2nd contact of the shorting piece J1, that is, the phase-shifted voltage output port of the integration unit 8. When the 1st contact and the 2nd contact of the shorting piece J1 are shorted, the 2nd contact of the shorting piece J1 directly outputs the given voltage set by the given unit 7, and at this time the whole system is in an open loop; when the 3rd contact and the 2nd contact of the shorting piece J1 are shorted, the 2nd contact of the shorting piece J1 outputs the phase-shifted voltage after the given integration link and voltage negative feedback regulation, and at this time the whole system is in a closed loop.

[0053] The integration unit 8 further includes integration capacitors C7 - C10, chip capacitors C1 - C6 for filtering, chip resistors R1 - R12, R15 - R17, R19 - R23 for filtering, switching diodes 1N4148 D9 - D10 and potentiometers W1 - W2 for the clamping circuit, resistors R18, switching diodes 1N4148 D1 - D2, D4 - D8 for setting the ratio, switching diode 1N4148 D3 for preventing reverse, and W6 for adjusting the amplification factor. The connection methods of the above electronic components are common knowledge in the art and are not elaborated in this application.

[0054] The protection unit 9 includes a dual D flip-flop CD4013, a voltage comparator LM311, a PNP transistor 8550 T1, and a thyristor 2P4M. The protection unit 9 has a phase loss protection port, an overheat protection port, a three-phase current mutual induction port, and an alarm signal output port. The overheat protection port is connected to the 3rd contact of the voltage comparator LM311 after being filtered by the chip resistors R31, R32, and a chip capacitor; the phase loss protection port is connected to the 3rd contact of the voltage comparator LM311 after being rectified by IN4007 and filtered by the chip resistors R33 - R35 and the capacitor C14; the three-phase current mutual induction port is connected to the 3rd contact of the voltage comparator LM311 after being rectified by a three-phase bridge uncontrolled circuit. The 7th contact of the voltage comparator LM311 is connected to the 6th contact of the dual D flip-flop CD4013. The 1st contact of the dual D flip-flop CD4013 is connected to the voltage feedback port of the voltage feedback control unit 4. The 12th contact of the dual D flip-flop CD4013 is connected to the base of the PNP transistor 8550 T1. At the same time, the base of the PNP transistor 8550 T1 is connected to the 15V power supply. The emitter of the PNP transistor 8550 T1 is connected to the 15V power supply through a zener diode. The collector of the PNP transistor 8550 T1 is connected to the control pole of the thyristor 2P4M. The input pole of the thyristor 2P4M, that is, the alarm signal output port of the protection unit 9, is connected to the alarm circuit 10, and the output pole of the thyristor 2P4M is grounded.

[0055] When there is no phase loss, overheat, overcurrent in the DC output, and short circuit in the DC output, the dual D flip-flop CD4013 is not activated. The base potential of the PNP transistor 8550 T1 is greater than the emitter potential of the PNP transistor 8550 T1, the PNP transistor 8550 T1 is cut off, and the thyristor 2P4M is cut off. When any one or more of the phase loss, overheat, overcurrent in the DC output, and short circuit in the DC output occur, the polarity of the voltage comparator LM311 flips. The 7th contact of the voltage comparator LM311 emits a high-level signal, the dual D flip-flop CD4013 is activated, the 1st contact of the dual D flip-flop CD4013 outputs a high level, cutting off the input of the voltage feedback port and the output of the 8th contact of the four-channel operational amplifier LM348. The 12th contact of the dual D flip-flop CD4013 outputs a low level. The base potential of the PNP transistor 8550 T1 is less than the emitter potential of the PNP transistor 8550 T1, the PNP transistor 8550 T1 conducts, controlling the thyristor 2P4M to conduct. In the case where the thyristor 2P4M conducts, the alarm circuit 10 conducts.

[0056] Such as Figure 7As shown, the alarm circuit 10 includes an alarm relay and a switching diode 1N4007 D127. The positive power supply terminal of the alarm relay is connected to the 24V power supply, and the negative power supply terminal of the alarm relay is connected to the input terminal of the thyristor 2P4M. The cathode of the switching diode 1N4007 D127 is connected to the positive power supply terminal of the alarm relay, and the anode of the switching diode 1N4007 D127 is connected to the negative power supply of the alarm relay to prevent reverse voltage.

[0057] As Figure 8 shown, the phase loss detection circuit 11 includes a fourth transformer B4. One end of the primary winding of the fourth transformer B4 is respectively connected to the three phases after being transformed by the rectifier transformer B5 through capacitors C103 - C105, and the other end is connected to the neutral line; one end of the secondary winding of the fourth transformer B4 is connected to the phase loss protection port of the protection unit 9, and the other end is grounded.

[0058] As Figure 2 shown, the current mutual inductance circuit 12 includes three current mutual inductance windings. The three current mutual inductance windings are respectively wound around the three-phase live wires after being transformed by the rectifier transformer B5. One end of the three current mutual inductance windings is connected together, and the other end is respectively connected to the three-phase current mutual inductance ports.

[0059] As Figure 9 shown, Figure 9 The schematic diagram of a power supply board provided in this embodiment is shown. The power supply board includes a third transformer B3, a rectification unit 13, and a voltage stabilization unit 14.

[0060] The primary winding of the third transformer B3 is connected to the AC circuit. The secondary winding of the third transformer B3 provides three-phase low-voltage alternating current and a synchronization voltage respectively.

[0061] The rectification unit 13 includes three single-phase bridge rectification circuits. The AC input poles of the three single-phase bridge rectification circuits are used to receive three-phase low-voltage alternating current, and the DC output poles of the three single-phase bridge rectification circuits are connected to the voltage stabilization unit 14.

[0062] The voltage stabilization unit 14 includes a three-terminal voltage regulator integrated circuit lm7815 IC1 and a three-terminal voltage regulator integrated circuit lm7915 IC2. The voltage stabilization unit 14 has a 15V port, a ground port, a -15V port, and a 24V port. The input contacts of the three-terminal voltage regulator integrated circuit lm7815 IC1 and the three-terminal voltage regulator integrated circuit lm7915 IC2 are respectively connected to the DC output poles of the three single-phase bridge rectification circuits as the positive and negative poles. The output contacts of the three-terminal voltage regulator integrated circuit lm7815 IC1 and the three-terminal voltage regulator integrated circuit lm7915 IC2 are divided into a 15V port, a ground port, a -15V port, and a 24V port after voltage regulation.

[0063] The above are all preferred embodiments of the present application, and do not limit the protection scope of the present application. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application shall be covered within the protection scope of the present application.

Claims

1. A thyristor control system for controlling thyristors in a three-phase bridge fully controlled rectifier circuit (1), characterized in that: include: Power board, regulation board, trigger board and isolation board, The power board is used to convert AC voltage into DC voltage and stabilize the voltage, and provide power to the regulating board, trigger board and isolation board; The isolation board is used to isolate the output voltage after rectification of the three-phase bridge full-controlled rectifier circuit (1) and feed back the voltage feedback signal generated after isolation to the regulating board; The regulating board is used to receive the given signal and the feedback signal of the isolation board, and adjust the output control signal according to the size of the given signal and the voltage feedback signal; The trigger board is used to provide a trigger pulse for the thyristor according to the output control signal and the synchronous voltage output by the regulating board, so as to control the output voltage of the three-phase bridge type full-controlled rectifier circuit (1). The trigger board comprises a trigger unit (2) containing a TC787 and six thyristor control units (3) containing capacitors. The thyristor control unit (3) is connected to a power board. The trigger unit (2) has a phase-shift voltage input port and six output ports. The thyristor control unit (3) is connected to the thyristor. The thyristor control unit (3) has a receiving port. The output ports of the trigger unit (2) are respectively connected to the receiving ports of the thyristor control unit (3). The thyristor control unit (3) controls the charging timing of the capacitor of the thyristor control unit (3) according to the signal received by the receiving port, so as to change the trigger pulse. The isolation board comprises a voltage feedback control unit (4), a voltage feedback unit (5) and a proportional reduction unit (6); the input end of the proportional reduction unit (6) is connected to the output end of the three-phase bridge full-controlled rectifier circuit (1); the voltage feedback unit (5) comprises a voltage feedback port; the voltage feedback unit (5) is associated with the proportional reduction unit (6) through a second transformer; the proportional reduction unit (6) proportionally reduces the output voltage to a detection voltage and transmits the detection voltage to the voltage feedback unit (5) through the second transformer; the detection voltage is converted into a voltage feedback signal by the voltage feedback unit (5) and outputted from the voltage feedback port; the voltage feedback control unit (4) is electrically connected to the power board; the voltage feedback control unit (4) is connected to the proportional reduction unit (6) through the first transformer; when the power board supplies power to the voltage feedback control unit (4), the voltage feedback control unit (4) transmits voltage to the proportional reduction unit (6) through the first transformer to make it conductive; and the voltage feedback control unit (4) can be associated with the proportional reduction unit (6) through the second transformer.

2. A thyristor control system according to claim 1, characterized in that: The regulating board comprises a given unit (7) and an integral link unit (8), the given unit (7) being used to set a given voltage, the given unit (7) being connected to the integral link unit (8) to provide a given voltage, the integral link unit (8) being electrically connected to the power board, the integral link unit (8) having a feedback receiving port and a phase-shift voltage output port, the phase-shift voltage output port of the integral link unit (8) being connected to the phase-shift voltage input port of the trigger unit (2), and the feedback receiving port being connected to the voltage feedback port of the voltage feedback unit (5).

3. A thyristor control system according to claim 2, characterized in that: The regulating board also includes a protection unit (9), the protection unit (9) having a phase loss protection port, an overheat protection port, a three-phase current mutual induction port and an alarm signal output port. The protection unit (9) is connected to the integral link unit (8), the alarm signal output port is connected to the alarm circuit (10), the phase loss protection port is connected to the phase loss detection circuit (11), the overheat protection port is connected to the motor load, and the three-phase current mutual induction port is connected to the current mutual induction circuit (12). When any one or more of the following conditions occurs: phase loss, overheat, DC output overcurrent and DC output short circuit, the protection unit (9) cuts off the integral link unit (8), and at the same time, the alarm signal output port of the protection unit (9) transmits a signal.

4. A thyristor control system according to claim 1, characterized in that: The power board comprises a third transformer, a rectifier unit (13) and a voltage stabilizing unit (14); the rectifier unit (13) and the voltage stabilizing unit (14) are connected; the voltage stabilizing unit (14) has a +15V port, a ground port, a -15V port and a +24V port; the primary winding of the third transformer is connected to the AC circuit; the rectifier unit (13) obtains low-voltage AC power through the secondary winding of the third transformer and rectifies it into DC power, which is then transmitted to the voltage stabilizing unit (14); and the voltage stabilizing unit (14) outputs DC power through the 15V port, the ground port, the -15V port and the 24V port after voltage stabilization.

5. A thyristor control device, characterized in that It comprises a three-phase bridge fully-controlled rectifier circuit (1) and a thyristor control system as claimed in any one of claims 1 to 4, wherein the trigger board is connected to the control electrode of the thyristor of the three-phase bridge fully-controlled rectifier circuit (1).

6. A thyristor control device according to claim 5, characterized in that: It also includes a rectifier transformer, the primary winding of the rectifier transformer is connected to the AC circuit, the secondary winding of the rectifier transformer is connected to the three-phase bridge type full-controlled rectifier circuit (1), and the rectifier transformer adopts a △ / Y0-11 connection method.

7. A thyristor control device according to claim 6, characterized in that It also includes a fast fuse, through which the rectifier transformer is connected to the three-phase bridge type full-controlled rectifier circuit (1).

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