CN115189605B - A controllable starting type twelve-pulse rectifier short-circuit impulse generator excitation system - Google Patents

Abstract

The invention discloses a controllable starting twelve-pulse rectification short-circuit impact generator excitation system. According to the invention, exciting current is provided for a rotor winding of a short-circuit impact generator by using a twelve-pulse rectifying device, harmonic interference of an exciting system to a power grid is effectively reduced, three-phase alternating current voltage is connected into a high-voltage switch, an alternating current power supply is provided for the twelve-pulse rectifying device after the voltage is reduced by a secondary side double-coil d0-y11 step-down transformer, a twelve-pulse triggering device provides triggering pulses for the twelve-pulse rectifying device, meanwhile, a starting resistor control device is adopted to control the switching device, so that the starting resistor is put on and cut off as required, the stable starting of the short-circuit impact generator is ensured, the problem that the starting resistor seriously heats when the short-circuit impact generator runs for a long time and a plurality of short-circuit impact generators are tested in parallel is effectively solved, and the short-circuit test of higher current level of the short-circuit impact generator is realized.

Description

Controllable starting twelve-pulse rectification short-circuit impact generator excitation system

Technical Field

The invention belongs to the field of high-capacity short-circuit impact generators, and particularly relates to a controllable starting twelve-pulse rectification short-circuit impact generator excitation system.

Background

And the high-capacity short-circuit impact generator operates under the working condition of sudden short circuit, outputs instantaneous huge short-circuit current and provides test current for a high-voltage conversion device sample. The short circuit impact generator excitation system is in a separate excitation mode and provides a direct current excitation power supply for the short circuit impact generator rotor excitation winding. The current widely used excitation system of the short-circuit impact generator adopts a six-pulse-wave silicon-controlled full-control rectifying device and an excitation system with a starting resistor connected in a long term, the structure provides effective conduction current for the silicon controlled rectifier through the starting resistor, and provides stable excitation current for the short-circuit impact generator through the six-pulse-wave silicon-controlled full-control rectifying device, so that the short-circuit impact generator is ensured to start stably and operate reliably.

The problems that firstly, a plurality of groups of high-power six-pulse rectification circuits work simultaneously to generate a large amount of harmonic current to flow into a power grid, and serious interference is caused to the power grid; secondly, the short-circuit current provided by the single short-circuit impact generator is insufficient to meet the current required by the test sample of the conversion device, a plurality of short-circuit impact generators are required to be used for parallel operation to provide larger current, and the plurality of short-circuit impact generators are required to be used for parallel operation after being sequentially started to an idle rated working condition, so that the electrified time of the excitation system is prolonged, and the starting resistor is connected in parallel in a rotor loop for a long time to bear the current, so that serious heating is caused, and the stability of the excitation system is influenced.

Disclosure of Invention

The invention aims to disclose a controllable starting twelve-pulse rectification short-circuit impulse generator excitation system which effectively reduces harmonic interference of an excitation system to a power grid through a twelve-pulse rectification principle and solves the problem of heating of a starting resistor under a long-term operation working condition of the excitation system by applying a starting resistor to disconnect a circuit. The three-phase alternating voltage is connected to a secondary side double-coil d0-y11 step-down transformer through a high-voltage switch, the secondary side double-coil d0-y11 step-down transformer outputs two groups of three-phase alternating voltages with the phase difference of 30 degrees to be connected to the alternating current side of a twelve-pulse wave rectifying device, a twelve-pulse wave triggering device sends pulses to the control side of the twelve-pulse wave rectifying device, the machine end voltage of a short-circuit impulse generator and the starting voltage threshold value of a short-circuit test enter a starting resistor control device, the starting resistor control device outputs the starting resistor to a switching device, and the starting resistor is connected with a de-excitation device and the rotor winding of the short-circuit impulse generator in series and then is connected with the direct current output of the twelve-pulse wave rectifying device to form a whole.

In the controllable starting twelve-pulse-wave rectification short-circuit impact generator excitation system, the twelve-pulse-wave rectification device is composed of a three-phase silicon controlled rectifier full-control rectification double-bridge group A, a three-phase silicon controlled rectifier full-control rectification double-bridge group B and a smoothing reactor with a middle tap, two groups of outputs of a secondary side double-coil d0-y11 step-down transformer are respectively connected to alternating current sides of the three-phase silicon controlled rectifier full-control rectification double-bridge group A and the three-phase silicon controlled rectifier full-control rectification double-bridge group B, the direct current positive electrode output of the three-phase silicon controlled rectifier full-control rectification double-bridge group A and the direct current positive electrode output of the three-phase silicon controlled rectifier full-control rectification double-bridge group B are connected in series through the smoothing reactor with the middle tap, the middle tap of the smoothing reactor is led out to be the direct current positive electrode output of the twelve-pulse-wave rectification device, and the direct current negative electrode output of the three-phase silicon controlled rectifier full-control rectification double-bridge group A and the direct current negative electrode output of the three-phase silicon controlled rectifier full-control rectification double-bridge group B are connected together to be led out to be the direct current negative electrode output of the twelve-pulse-wave rectification device.

In the above-mentioned twelve pulse wave rectification short circuit impulse generator excitation system of controllable start-up, start-up resistance control device comprises analog quantity collection module, settlement module, parameter integration module, switch control output module, and short circuit impulse generator machine end voltage enters into parameter integration module after analog quantity collection module processes, and short circuit test start-up voltage threshold enters into parameter integration module through settlement module, and parameter integration module's output enters into switch control output module, and switch control output module's output is the control signal of start-up resistance control device output.

In the controllable starting twelve-pulse wave rectifying short-circuit impact generator excitation system, the switching device is composed of a control signal receiving module, a low-voltage-to-high-voltage conditioning module and a starting switch module, wherein the control signal receiving module receives a control signal output by the starting resistor control device, the output of the control signal receiving module is connected to the low-voltage-to-high-voltage conditioning module, the output of the low-voltage-to-high-voltage conditioning module is connected to the starting switch module, and the output of the starting switch module is the output of the switching device.

Compared with the prior art, the invention has the beneficial effects that:

1. The invention can effectively reduce harmonic interference brought by short circuit impact generator excitation system to the power grid. The twelve-pulse rectifying device can improve 5 times, 7 times and 9 times of harmonic waves brought by the traditional excitation system, thereby reducing harmonic interference brought by the traditional short-circuit impact generator excitation system to a power grid.

2. The invention can realize parallel test of a plurality of short-circuit impact generators and provide larger short-circuit test current for the conversion device test sample. The switching device can disconnect the starting resistor, effectively avoids the heating burning problem caused by long-term pressure bearing of the starting resistor, enables a single short-circuit impact generator to run for a long time under the no-load rated working condition, and waits for a plurality of parallel tests to be carried out after the starting of other short-circuit impact generators is completed.

Drawings

Fig. 1 is a detailed view of a controllable start twelve-pulse rectification short-circuit impulse generator excitation system.

Fig. 2 is a detailed view of the twelve-pulse rectifying device.

Fig. 3 is a detailed view of the starting resistance control device.

Fig. 4 is a detailed view of the switching device.

The reference sign shows that the device comprises a 1-high voltage switch, a 2-secondary side double-coil d0-y11 step-down transformer, a 3-twelve pulse wave rectifying device, a 4-starting resistor, a 5-switching device, a 6-demagnetizing device, a 7-short circuit impact generator rotor winding, an 8-twelve pulse wave triggering device, a 9-starting resistor control device, a 10-three-phase thyristor full-control rectification double-bridge group A, a 11-three-phase thyristor full-control rectification double-bridge group B, a 12-smoothing reactor with a middle tap, a 13-analog quantity acquisition module, a 14-setting module, a 15-parameter integration module, a 16-switching control output module, a 17-control signal receiving module, a 18-low voltage to high voltage conditioning module and a 19-moving switch module.

Detailed Description

The invention is further described below with reference to the drawings and the detailed description.

As shown in fig. 1, the excitation system of the controllable starting twelve-pulse rectification short-circuit impulse generator consists of a high-voltage switch 1, a secondary double-coil d0-y11 step-down transformer 2, a twelve-pulse rectification device 3, a starting resistor 4, a switching device 5, a de-excitation device 6, a short-circuit impulse generator rotor winding 7, a twelve-pulse triggering device 8 and a starting resistor control device 9. The three-phase alternating voltage is connected to a secondary double-coil d0-y11 step-down transformer 2 through a high-voltage switch 1, the secondary double-coil d0-y11 step-down transformer 2 outputs two groups of three-phase alternating voltages with the phase difference of 30 degrees to be connected to the alternating current side of a twelve-pulse wave rectifying device 3, a twelve-pulse wave triggering device 8 sends pulses to the control side of the twelve-pulse wave rectifying device 3, the machine end voltage of a short-circuit impulse generator and the starting voltage threshold value of a short-circuit test enter a starting resistor control device 9, the starting resistor control device 9 outputs the starting resistor to a switching device 5, and the starting resistor 4 is connected with a DC output of the twelve-pulse wave rectifying device 3 in parallel with a de-excitation device 6 and a short-circuit impulse generator rotor winding 7 after being connected in series with the switching device 5, so that the whole is formed. The high-voltage switch 1 is closed, three-phase alternating voltage is reduced by the secondary side double-coil d0-y11 to provide alternating current power for the twelve-pulse rectifying device 3 after being reduced by the transformer 2, the starting resistance control device 9 processes software according to the terminal voltage of the short-circuit impact generator and the starting voltage threshold value of the short-circuit test to output control signals to the switching device 5, the switching device 5 controls the input and the withdrawal of the starting resistance 4 according to the received control signals, the stable starting of the generator is ensured, the starting resistance 4 can not generate heat, the twelve-pulse triggering device 8 outputs pulses to the twelve-pulse rectifying device 3 according to test requirements, the twelve-pulse rectifying device 3 outputs direct current to the rotor winding 7 of the short-circuit impact generator, the short-circuit impact generator enters an idle rated state, at the moment, the short-circuit test of the single short-circuit impact generator can be directly performed, and if higher-circuit current is required, the short-circuit impact generators are respectively started to the idle rated state according to the steps, and then the short-circuit test of the short-circuit impact generators is performed in parallel.

As shown in fig. 2, the twelve-pulse rectifier 3 is composed of a three-phase thyristor full-controlled rectifier double-bridge group a10, a three-phase thyristor full-controlled rectifier double-bridge group B11, and a smoothing reactor 12 with a middle tap, two groups of outputs of the secondary double-coil d0-y11 step-down transformer 2 are respectively connected to ac sides of the three-phase thyristor full-controlled rectifier double-bridge group a10 and the three-phase thyristor full-controlled rectifier double-bridge group B11, a direct current positive output of the three-phase thyristor full-controlled rectifier double-bridge group a10 and a direct current positive output of the three-phase thyristor full-controlled rectifier double-bridge group B12 are connected in series through the smoothing reactor 12 with the middle tap, a direct current positive output of the smoothing reactor 12 with the middle tap is led out of the twelve-pulse rectifier 3, and a direct current negative output of the three-phase thyristor full-controlled rectifier double-bridge group a10 and a direct current negative output of the three-phase thyristor full-controlled rectifier double-bridge group B11 are connected together to be led out of the direct current negative output of the twelve-pulse rectifier 3. When the short-circuit impact generator set is tested, the high-voltage switch 1 is closed, three-phase alternating voltage enters the alternating current side of the twelve-pulse-wave silicon controlled rectifier full-control rectifier bridge 3 through the secondary side double-coil d0-y11 step-down transformer 2, the twelve-pulse-wave triggering device 8 sends pulses to the control side of the twelve-pulse-wave rectifier device 3 according to actual working conditions, the smoothing reactor 12 with a middle tap absorbs instantaneous difference values of two groups of three-phase silicon controlled rectifier full-control double-bridge line voltages, the twelve-pulse-wave rectifier device 3 is guaranteed to output stable twelve-pulse-wave voltages, and harmonic interference of a system to a power grid is effectively reduced.

As shown in fig. 3, the starting resistor control device 9 is composed of an analog quantity acquisition module 13, a setting module 14, a parameter integration module 15 and a switch control output module 16, the terminal voltage of the short-circuit impulse generator is processed by the analog quantity acquisition module 13 and then enters the parameter integration module 15, the starting voltage threshold of the short-circuit test enters the parameter integration module 15 through the setting module 14, the output of the parameter integration module 15 enters the switch control output module 16, and the switch control output module 16 is a control signal output by the starting resistor control device 9. Before the short-circuit impact generator test, the starting voltage threshold values corresponding to the short-circuit tests with different current levels are input into the setting module 14, the setting module 14 processes the starting voltage threshold values and then enters the parameter integration module 15, in the short-circuit impact generator starting process, the analog quantity acquisition module 13 samples the terminal voltage of the short-circuit impact generator and then enters the parameter integration module 15, the parameter integration module 15 processes the received numerical value and then outputs a control signal to the switch control output module 16, the signal of the switch control output module 16 is used as the output signal of the starting resistance control device 9, and the starting resistance control device 9 is guaranteed to control the switch device 5 according to the short-circuit test requirements with different current levels.

As shown in fig. 4, the switching device 5 is composed of a control signal receiving module 17, a low-voltage to high-voltage conditioning module 18 and a starting switch module 19, the control signal receiving module 17 receives a control signal output by the starting resistor control device 9, the output of the control signal receiving module 17 is connected to the low-voltage to high-voltage conditioning module 18, the output of the low-voltage to high-voltage conditioning module 18 is connected to the starting switch module 19, and the output of the starting switch module 19 is the output of the switching device 5. In the starting process of the unit, the control signal receiving module 17 sends a control signal of the starting resistor control device 9 to the low-voltage-to-high-voltage conditioning module 18, and the low-voltage-to-high-voltage conditioning module 18 controls the on-off of the starting switch module 19, so that the starting resistor is put into and disconnected as required, the starting resistor is free-wheeling of the silicon controlled rectifier in the twelve-pulse rectifying device 3, meanwhile, the starting resistor is prevented from being put into severe heating for a long time, and the stability of an excitation system is improved.

The invention is suitable for the excitation system of the high-capacity short-circuit impact generator, can effectively solve the problems existing in the traditional design scheme, and has the characteristics of high module integration, good stability, obvious effect and the like.

Finally, the protective scope of the invention is not limited to the embodiments described above. It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the scope or spirit of the invention. The present invention is intended to include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims (3)

1. A controllable starting type twelve-pulse rectifier short-circuit impulse generator excitation system, characterized in that it is composed of a high-voltage switch (1), a secondary double-coil d0-y11 step-down transformer (2), a twelve-pulse rectifier (3), a starting resistor (4), a switch device (5), a demagnetization device (6), a short-circuit impulse generator rotor winding (7), a twelve-pulse trigger device (8), and a starting resistor control device (9). The three-phase AC voltage is connected to the secondary double-coil d0-y11 step-down transformer (2) through the high-voltage switch (1). The double-coil d0-y11 step-down transformer (2) outputs two sets of three-phase AC voltages with a phase difference of 30° and is connected to the AC side of the twelve-pulse rectifier (3). The twelve-pulse trigger device (8) sends pulses to the control side of the twelve-pulse rectifier (3). The short-circuit impulse generator terminal voltage and the short-circuit test starting voltage threshold enter the starting resistor control device (9). The starting resistor control device (9) outputs to the switch device (5). The starting resistor (4) is connected in series with the switch device (5) and then connected to the demagnetization device (6) and the short-circuit impulse generator. The sub-winding (7) is connected in parallel to the DC output of the twelve-pulse rectifier (3) to form a whole. The twelve-pulse rectifier (3) is composed of a three-phase thyristor fully controlled rectifier double bridge group A (10), a three-phase thyristor fully controlled rectifier double bridge group B (11), and a smoothing reactor (12) with an intermediate tap. The two groups of outputs of the secondary double-coil d0-y11 step-down transformer (2) are respectively connected to the AC side of the three-phase thyristor fully controlled rectifier double bridge group A (10) and the three-phase thyristor fully controlled rectifier double bridge group B (11). The three-phase thyristor fully controlled rectifier double bridge group The DC positive output of the bridge group A (10) and the DC positive output of the three-phase thyristor fully controlled rectifier double bridge group B (11) are connected in series via a smoothing reactor (12) with a middle tap, and the middle tap of the smoothing reactor (12) with a middle tap is led out as the DC positive output of the twelve-pulse rectifier device (3), and the DC negative output of the three-phase thyristor fully controlled rectifier double bridge group A (10) and the DC negative output of the three-phase thyristor fully controlled rectifier double bridge group B (11) are connected together and led out as the DC negative output of the twelve-pulse rectifier device (3). 2. A controllable starting twelve-pulse rectifier short-circuit impulse generator excitation system according to claim 1, characterized in that: the starting resistance control device (9) is composed of an analog quantity acquisition module (13), a setting module (14), a parameter integration module (15), and a switch control output module (16); the short-circuit impulse generator terminal voltage enters the parameter integration module (15) after being processed by the analog quantity acquisition module (13); the short-circuit test starting voltage threshold enters the parameter integration module (15) through the setting module (14); the output of the parameter integration module (15) enters the switch control output module (16); and the output of the switch control output module (16) is the control signal output by the starting resistance control device (9). 3. A controllable starting type twelve-pulse rectifier short-circuit impulse generator excitation system according to claim 1, characterized in that: the switch device (5) is composed of a control signal receiving module (17), a low voltage to high voltage conditioning module (18), and a starting switch module (19), the control signal receiving module (17) receives the control signal output by the starting resistance control device (9), the output of the control signal receiving module (17) is connected to the low voltage to high voltage conditioning module (18), the output of the low voltage to high voltage conditioning module (18) is connected to the starting switch module (19), and the output of the starting switch module (19) is the output of the switch device (5).