SU1046898A2 - Device for control of inverter - Google Patents

Abstract

device for controlling the INVERTER auth. St. 961098, characterized in that, in order to increase stability (r77 / g / V and improve the dynamic characteristics of the inverter, it is equipped with a block of adjustable pulses, as an AND element, reversible counter, code-phase converter, variable frequency generator, the first input of the element And it is connected to the output of the comparison block, second through a variable frequency generator, to the output of the code-phase converter, and the output is connected to the counting input of a reversible counter, the output of which is connected to the input of the code-phase converter, and the output azovatel code phase is intended for connection to the gate electrodes in a trench tiristoO average inverter rack X:. of EO T4

Description

The invention relates to electrical engineering and can be used to regulate a rectifying inverter converter in an inverter mode at a constant storage margin. On the basis of auth. St. No. 961098, a device is known that contains a comparison element, one input of which is connected to the output of the stock angle setting setpoint and the other to the output of the stock angle sensor, the input regulator of which is connected to the output of the reference element, and output to the output of the FPE pulse converter, output phase pulse converter is connected to the controller input. This device regulates the inverter to the constancy of the reserve coal with the implementation of non-linear feedback in the stock angle of the thyristors of the rectifying-inverter converter E. The disadvantage of this device is the presence of positive feedback on the inverter current. This is reflected in the fact that when the inverter's reserve angle is reduced to values below a predetermined value, the regulator decreases the valve unlocking angle to increase the reserve angle to a standard value. In turn, this decreases the voltage at the output of the converter, which causes a further increase in the current of the inverter and a new decrease in the reserve angle. This method of control reduces the quality of regulation of the inverter in a transient regime, which requires an increase in the specified value of the angle of stock and, thereby, impairs the energy performance of the regenerative braking mode. The purpose of the invention is to ensure the stability of the inverter in transition modes and to improve the dynamic characteristics of the converter. The goal is achieved by the fact that the device for controlling the inverter is equipped with a block of adjustable pulses, as an element AND of a reversible counter, converts the code - phase of the variable frequency generator, the first input of the AND element is connected to the output of the comparison unit, the second through the variable frequency generator - with the output the code converter is the phase, and the output is connected to the counting input of the reversible counter, the output of which is connected to the input of the code converter is the phase, and the output of the code-phase converter is intended for connecting Eni with control electrodes of the thyristors of the central rack of the inverter. FIG. 1 shows a block diagram of the device proposed; in fig. 2 is a timing diagram of the inverter output voltage; in fig. 3 is a block diagram of a specific embodiment of a block of adjustable pulses; in fig. 4 is a block diagram of a specific, execution of the controller. The device for adjusting the inverter to the constancy of the stock angle contains a stock angle adjuster 1, a comparison unit 2, a stock angle sensor 3, a controller 4, a pulse-phase converter 5, an inverter 6, an adjustable pulse unit 7, the adjustable pulse unit 7 being made as an element I 8, the first input of which is connected to the output. unit 2 of the comparison, and the output through the reversible counter 9 is connected to the input of the converter 10 of the code phase, one output of the converter 10 is designed to be connected to the electrodes of the central stand, the inverter 6, and the other output through the generator. The variable frequency terminals 11 are connected to the second input of the AND element 8, the first inputs of the elements 12 and 13 of the controller 4 are connected to the output of the comparator unit 2, the second inputs through the variable frequency generator unit 14 are connected to the output of the phase-pulse converter 5, and the outputs of the elements 12 and 13 connected to the corresponding inputs of the binary counter 15, the output of which is connected to the input of the phase-pulse converter 5.. The device works as follows. In each half-period of the voltage in block 2, block 2 compares the set value of the stock angle (coming from setpoint 1 with the current value of the stock angle (T coming from sensor 3, and detecting the error from the stock angle dsG-sG, -sgt) This mismatch is supplied to the input of the regulator 4,. in the controller 4, the time interval D (G, depending on its sign is filled in the elements And 12 min 13 4 FIG. 4) variable frequency pulses {formed by the variable frequency generator 14. The pulse frequency is determined by A signal | unloading signals of thyristors generated by a phase-impulse converter 5. The frequency-modulated signal urff is fed from the outputs of elements 12 and 13 to summation or to the subtracting input of a reversible binary counter 15. Thus, the controller 4 generates a signal proportional to the phase of the angle unlocking the thyristors in the h -th half-period s sCpr, depending on the magnitude of the mismatch ISH and the value of the phase of the control pulse of the previous half-period

iiv, i.e., and (fc (f, jby, -). The code at the output of the counter 15 is converted by the converter 5 into phase-impulse information. The pulses formed in block 5 are fed to thyristors 16-19.

The time interval of the signal from the comparison unit by means of the elements of And 8 is filled with pulses shaped by a variable frequency generator 11. These pulses change the code at the output of counter 9, which is proportional to the phase of the recooled pulse B Bp. Code changes can also be made from the machine controller nm. The conversion of code information into a pulse one is carried out in a code converter 10 - phase U).

The Dar OToip dependency is taken into account by pulse-width modulation of the interval / srf in accordance with the tip value at the output of the code converter 10 — phase for which the converter 10 code phase is connected to the generator input 11, then the frequency at the generator output 11 changes in this way During the formation of wolp, the area of 5 54 5e was fulfilled.

Values 5 and 5 are equal (Fig. 2).

Bd v j) 5i "it; ta4) t

.

3 J) tdu) t, ii

where and is the amplitude value of the zone voltage supplying the inverter -,

K - regulation zone. With equality ii 5

 iwtaoit t u (k - i) siniutau t

moreover, in accordance with FIG. 2

we introduce the notation

 , U) t, i-Ap (li .-,) 4-6d-p

UJi, j-Ib-Cf ,,

 t-td-j-urf)

Then, u t-cos (a.p,) + cosc p,

-SK-) and „CC05 () - С05 (GO COS (ci.,.,) &Amp; oLp) (K-1) cOS (cf4-u.rf) -С05СГ SO% Ap („., -,

Transforming the resulting expression, we define the corrective action on the phase of the pulses it controls.

Ad.psQrcCO С (К-1) COV ((G) () COS (f -COSd.p. ,,.

Block 7 adjustable pulses generates signals unlocking

 which are served on. thyristors 20 and 21. At the same time, to eliminate the positive feedback on the current of the inverter, the input of block 7 is given a urf signal from the output of block 2 of the comparison, In this case, when the current value of the angle of the reserve decreases (Г mismatch (Г О and increase the unlocking angle of the controlled pulses oLp by the value of ucip, i.e. a decrease in the output voltage of the inverter by an amount proportional to the area will be compensated for by increasing it by adding the area So,.

Q The output signal of the block of adjustable pulses is fed to the first input of this block, since due to the sinusoidal nature of the supply voltage, the change in the phase of the adjustable pulses oip does not depend

 only from the mismatch in the angle of the stock L (G, but also from its current value of op, i.e.

& oLp iUcr, ol.p)

The introduction of a block of adjustable pulses covered by feedback allows the development of the error between the set and the current values of the inverter stock angle to stabilize the output voltage.

5 by eliminating the positive feedback of the inverter current. This increases the stability and improves the dynamic characteristics of the rectifier-inverter in regenerative braking mode.

l5 5

 Jl I cfflfn)

Ing

iaf

J-u

Claims (1)

DEVICE FOR MANAGING INVERTER by ed. St. No. 961098, characterized in that, in order to increase the stability and improve the dynamic characteristics of the inverter, it is equipped with a block of adjustable pulses, in the form of an And element, a reversible counter, a code-phase converter, a variable frequency generator, and the first input of the And element connected to the output comparison unit. the second through a variable frequency generator - with the output of the code-phase converter, and the output is connected to the counting input of the reverse counter, the output of which is connected to the input of the code-phase converter, and the output of the converter to od-phase is designed to connect with the control electrodes of the thyristors of the middle rack of the inverter.