CN104601056A

CN104601056A - Triggering control method of synchronous motor excitation device

Info

Publication number: CN104601056A
Application number: CN201510037053.5A
Authority: CN
Inventors: 冉啟柏
Original assignee: Wengfu Group Co Ltd
Current assignee: Wengfu Group Co Ltd
Priority date: 2015-01-26
Filing date: 2015-01-26
Publication date: 2015-05-06

Abstract

A triggering control method of a synchronous motor excitation device comprises the following steps: a TCD-II transistor control device is used for replacing eight excitation control discrete plug-in units of excitation, de-excitation, giving, A-phase triggering, B-phase triggering, C-phase triggering, state and out-of-control of a BKL-I excitation device; the TCD-II transistor control device takes a phase shift trigger TC787 integrated circuit as a core circuit. The triggering control method has the advantages that the cost is low; the structure depends on existing excitation variation, a three-phase half-controlled bridge thyristor primary circuit and an excitation protection link; only one TCD-II transistor excitation control device is needed and is accurately accessed into input and output circuits; giving, feedback, excitation current, under-excitation and over-excitation adjustment are convenient. A special single chip integrated circuit is adopted and the performance is reliable, the power consumption is low and the service life is long. The triggering control method can be applied to the field of triggering control of the synchronous motor excitation device.

Description

A kind of synchronous motor excitation unit trigger control method

Technical field

The present invention relates to electrotechnics, furthermore, relate to a kind of synchronous motor excitation unit trigging control

Method.

Background technology

It is high that synchronous motor has efficiency, stabilization of speed, can improve the feature such as factory and power factor of electric network, apply widely in industrial and mining enterprises.But for a long time, operating synchronous motor and excitation unit failure rate high, the normal operation that frequent impact is produced, through a large amount of accident analyses, the fault of synchronous motor own is little, and main cause is caused by synchronous motor excitation unit technical performance difference, and major failure is excitation trigger control unit, whether the performance of trigger control unit, quality, directly affect synchronous motor and run safely and reliably.Synchronous motor often adopts BKL-I excitation unit, and this device adopts fabricated structure, is formed by excitation transformer, rectifier cabinet, control cubicle three incorporating aspects.This device major loop adopts without the half-controlled bridge type silicon controlled rectification circuit of fly-wheel diode; trigging control is encouraged by throwing, demagnetization, given, triggering, state, out of control, band are encouraged Falling out of step with fields protected location and formed; each unit is separated plug-in unit electronic component; system protection is loaded down with trivial details with debugging; failure rate is high, difficult in maintenance.

Summary of the invention

The object of the present invention is to provide a kind of synchronous motor excitation unit trigger control method, improve synchronous motor excitation unit technical performance, reduce synchronous motor fault.

A kind of synchronous motor excitation unit trigger control method of the present invention, the method is that the throwing replacing BKL-I excitation unit with TCD-II solid-state control is encouraged, demagnetization, given, trigger A phase, trigger B phase, trigger C phase, state, eight pieces of discrete bound cells of excitation con-trol out of control, described TCD-II solid-state control with phase shift trigger TC787 integrated circuit for core cell.

The invention has the advantages that:

1, cost is low, and this structure depends on the change of existing excitation, three-phase half controlled bridge thyristor primary circuit, excitation protection link, only needs a TCD-II transistor excitation controlling device.

2, Installation and Debugging are convenient and swift, removed by the trigging control plug-in unit in old device, pacify into TCD-II excitation trigger controller, correct access input and output circuit, and given, feedback, exciting current, underexcitation, mistake are encouraged easy to adjust.

3, monolithic application-specific integrated circuit (ASIC) is adopted, dependable performance, low in energy consumption, long service life.

4, integrated level is high, easy to maintenance, this control board collection demagnetization, throw encourage, throw that total head, pulse shaping, phase shift are given, the circuit such as pulse amplifying and output, protection, power supply, can failure judgement processing fast and accurately when being out of order.

The present invention has good static characteristic and dynamic characteristic, and plant running reliability and stability are high.

The present invention can be applicable to synchronous motor excitation unit trigging control field.

Accompanying drawing explanation

Fig. 1 is TC787 circuit theory and logic diagram, and Fig. 2 is TCD-II excitation trigger controller structure chart, and Fig. 3 is reconstruction structure figure of the present invention.

Fig. 1 illustrates TC787 circuit theory: three-phase synchronous voltage enters circuit through T-shaped network, the zero point of synchronizing voltage is designed to 1/2 supply voltage (circuit input synchronizing voltage peak value should not be greater than supply voltage), after going out zero point and polarity by zero passage detection and polarity discriminating electric circuit inspection, at Ca, Cb, Cc tri-electric capacity upper integrals form sawtooth waveforms, owing to adopting centralized constant-current source, relative error is minimum, sawtooth waveforms has good linear, choosing of electric capacity answers relative error little, produce sawtooth amplitude greatly and not flat-top be advisable, sawtooth waveforms compares with phase-shifting voltages in a comparator and obtains phase point, phase-shifting voltages is obtained by potentiometer or external circuit adjustment by 4 pin, anti-jamming circuit has lock function, after handing over phase point, the fluctuation of sawtooth waveforms or phase-shifting voltages can not affect output, ensure to hand over unique mutually and stablize.Pulse shaping circuit provides modulating pulse (TC787) by pulse generator, and modulating pulse width is determined by the value changing Cx electric capacity, and need wide, increase Cx, narrow, reduce Cx, 1000P electric capacity about produces the pulse duration of 100us.Pulse distribution and drive circuit are by the way of output of 6 foot control pulse distribution, 6 pin meet low level VL, export as half control mode, 12,11,10,9,8,7 ono shot pulses exporting A ,-C, B ,-A, C ,-B respectively, 6 pin meet high level VH, export as full prosecutor formula, export A ,-C respectively;-C, B; B ,-A;-A, C; C ,-B; Two trigger impulses of-B, A, user can select, and 5 pin are protection end, when overcurrent, overvoltage appear in system, 5 pin are set high level VH, and exporting pulse can forbid.

Fig. 2 illustrates TCD-II excitation trigger controller structure and System Working Principle: the eliminationg work when synchronous motor starts, and makes rotor respond to the positive and negative half-wave of alternating voltage all by discharge resistance, ensures the normal startup of motor.In start-up course, rectification circuit controllable silicon no pulse, is in blocking state.When electric motor starting is to metasynchronism (rotor slippage to 0.05), throw and encourage link and automatically send throwing and encourage signal, trigger impulse is added on rectification thyristor, and silicon controlled rectifier puts into excitation to motor immediately, makes synchronous machine pull synchronous operation into.The voltage signal that controller power source part is introduced by negative voltage feedback link and Setting signal comprehensively, when ensureing voltage ripple of power network, keep rectification to export excitation substantially constant, to realize the constant excitation megnet to motor.Throw total head link for electric machine step-down starting setting, the pulse that this link sends, by the total head switch of Control motor stator side, makes it by slippage precision maneuver of adjusting.

Fig. 3 illustrates that the throwing replacing BKL-I excitation unit with TCD-II solid-state control is encouraged, demagnetization, given, trigger A phase, trigger B phase, trigger C phase, state, eight pieces of discrete bound cells of excitation con-trol out of control.

embodiment

Below in conjunction with embodiment, the invention will be further described.

embodiment:

There are six air compressors in certain chemical company of Co., Ltd, motor is the synchronous motor of 250KW, use BKL-I type excitation unit, now adopt the inventive method, BKL-I trigging control is thrown and encourages, demagnetization, given, state, triggering A phase, trigger B phase, trigger the discrete plug-in units of C phase eight blocks and remove, loading TCD-II excitation trigger controller.During startup, control cubicle is to high-tension switch cabinet switching signal, high-tension switch cabinet auxiliary switch normally opened contact closes to TCD-II controller switching signal, controller power source switch closes, trigger controller exports enabling signal to BKL-I rectifying device, controls rectifier cabinet and starts controllable silicon work, makes synchronous electric motor rotor respond to alternating current two half-wave and is all discharged by discharge resistance, ensure the normal startup of synchronous motor, in start-up course, block the control trigger impulse of rectification thyristor simultaneously.When synchronous motor starts to metasynchronism, controller sends start pulse signal on rectification thyristor, and excitation puts into excitation to synchronous motor immediately, and synchronous motor is pulled into synchronous operation.When synchronous motor step-out or when shutting down, TCD-II exports demagnetization signal to BKL-I rectifying device, and demagnetization controllable silicon works, and resistance-capacitance circuit carries out demagnetization to synchronous electric motor rotor.When loss of excitation and belt encourage step-loss or cross encourage, underexcitation protection action time; controller detects output protection signal to BKL-I excitation protection device by current feedback signal; the time delay of excitation protection device exports trip signal to high-tension switch cabinet; high-voltage switch cabinet breaker tripping operation makes synchronous motor out of service; high-tension switch cabinet auxiliary switch disconnects TCD-II simultaneously, demagnetization circuit work.

Claims

1. a synchronous motor excitation unit trigger control method, be that the throwing replacing BKL-I excitation unit with TCD-II solid-state control is encouraged, demagnetization, given, trigger A phase, trigger B phase, trigger C phase, state, eight pieces of discrete bound cells of excitation con-trol out of control, described TCD-II solid-state control with phase shift trigger TC787 integrated circuit for core cell.