SU851729A1 - Device for pulse-phase control of converter - Google Patents

Description

The invention relates to electrical engineering and can be used in an automated valve-driven electric drive. A device for pulse-phase control (SIFU) is known, which contains filters, saw-tooth voltage generators at adders, drivers of control pulses, power valve block, control signal source D-1. However, this device is characterized by low noise immunity. The closest to the proposed technical entity is a device containing adders, an integral of a controller, amplifiers, driver-formers, and Jiz power units. A disadvantage of the known device is low noise immunity. The purpose of the invention is to increase resistance to resistance. The goal is achieved by the fact that. The device is equipped with a frequency-analog converter, and in each phase an additional summer G amplitude modulator and a relay element, the input of the relay element serving to connect to the voltage source the corresponding phase, and the output is connected to the first input of the amplitude modulator, the second input of which is connected through the first input of the additional adder to the output of the frequency-analog converter, the output to the third input of the adder, the second input of the additional adder serves to connect to the reference source A signal, an input of a frequency converter, is used to - connect to the voltage source of one of the phases. The drawing shows a functional diagram of the device. The device contains additional adders 1-3, adders 4-6, amplitude modulators 7-9, integrators 10-12, amplifiers of direct current 13-15, drivers of control pulses 16-18, unit 19 of power valves, frequency converter 20 analogue and relay elements 21-23. The drawing also indicates: xTt) - control signal; Ho reference signal (ho iconst); xd (1), X (1), Xc (t) voltage from the corresponding phase SIFU. The principle of operation of each channel of the corresponding phase SIFU is identical. The device works as follows.

The relay elements 21-23 have a small value with respect to the amplitude of the voltages x (t),) and XgCt. switching thresholds and are designed to convert sinusoidal voltages into rectangular different-polarized pulses with an average zero value. The moment of changing the sign of the signal at the output of the elements 21-23 practically corresponds to the point in time when the conditions are met

0, Xc (t).

Xg (t)

xd (and Oh,

-The pulses at the output of the relay elements 21-23 have a fixed amplitude, independent of amplitude. phase voltages.

The signal from the output of the relay element 21 is fed to the input of the amplitude modulator 7, where it is limited by the c1 amplitude at level i x. The value of the reference signal x determines the initial value of c1MpL of the pulses at the input of the adder 4, and their frequency is equal to the frequency of the voltage Hd (1) .. The amplitude of the pulses on. the modulator output 7 must exceed the value of the acceptable channel input signal. In this case, the channel link goes into the mode of forced oscillations with a voltage frequency x. (T). Under the influence of the control signal X (t), the sawtooth signal at the output of the integrator 10 is shifted vertically relative to the threshold voltages of the amplifier 13, which causes a change in the duty cycle of its output pulses.

The imaging unit 16 applies control pulses to the corresponding gate of the unit 19.

Converter 20 generates a signal proportional to the frequency of eg CNIF network. In adders 1-3. the summation of the signals occurs. Increasing the frequency of the voltages xd (1) ,. Xjg (t), XgCt) causes an increase in the amplitude of the voltage at the output of the converter 20. As a result, the amplitude of the pulses at the output of the modulators 7–9 increases, which ensures that the condition

where TD is constant time-.

Tu, is the synchronization period

impact;

Ац is the relative value of the amplitude of the synchronizing signal, t i: e. independence of dynamic characteristics

SIFU (degree of noise immunity) of the amplitude and frequency stability of the stresses XdX t), Xgd), Xc (t).

Thus, the relay elements 21-23 stabilize the characteristics of SIFUs in amplitude and the converter 20 in terms of the frequency of the voltages Xd (d), X.g (t), Xc, (t).

Thus, the proposed device differs from the known higher noise immunity to additive interference signals with. SIFU information entry side.

Claims (2)

1. Shipillo V.P., Vutalov O.G. Calculation of semiconductor control systems of valve converters. $ Energy, 1966, p. 144 2. USSR Author's Certificate for Application No. 2680999 / 24-07, cl. H 02 R 13/16, 1978.