SU731548A1 - Method of control of parallel static converters connected to subdivided transformer - Google Patents

Description

lei by the amount of Do, and the adjustable angle of the subsequent zone of the second group of transducers is larger than the adjustable angle of the first group of transducers by the value of Areg. the second half-period of the mains takes the opposite picture.

The phase difference of like pulses (AO and Areg) is chosen as a function of the respective control angles and the magnitude of the load current.

As an example, consider the application of the proposed control method to parallel-operating rectifier inverter converters of the VL80R locomotive.

FIG. Figure 2 shows the proposed functional control circuit of the converters.

FIG. 3 is a simplified schematic diagram of a single VL80R electric locomotive converter.

The control unit 1, which forms the control pulses with the predetermined unlocking angle (oo) and the phase-adjustable unlocking angle (org) control pulses, is connected to the delay block 2, which performs the control pulses delay for the time A / (areg, /) connected to the logical elements 3, 4.

Logic elements 3, 4 are connected to static converters 5-8, which in turn are connected to power transformers 9, 10. Positions 11-14 designate the load of static converters 5-8 (for example, traction motors), positions 15- 22 in FIG. 3 - thyristor shoulders of a static converter, nanometer 5, connected to the secondary windings 23, 24, 25 of the power transformer 9 or 10, position 26 - the load of the converter.

FIG. Figure 1 shows a control diagram of parallel-connected converters (for example, 5 and 6).

Suppose the transducers operate in the fourth voltage control zone. Then on the shoulders 17, 22, in one of the half periods and 18, 21, control pulses with a given unlocking angle (OQ-fAo) are supplied to the next half period of each parallel-connected converter, and the phase control is performed by changing the angle of the shoulders 15, 16, by which respectively receive control pulses with angles

(aper-f Areg) and ttper.

at the moment of time preceding the phase voltage regulation, all the converters operate with the fully selected 3rd control zone and control emulses are supplied to the shoulders 17, 22 and 18, 21 of each converter with a given unlocking angle ao. When the phase regulation at time i on the shoulders 17, 22 of the transducer 5 (direction

The EMF of the transformer is indicated in FIG. 3) control pulses are passed with a given angle of unlocking ao, and in a moment

.

5 The pulses are applied to the shoulders 17, 22 of the transducer 6 with a predetermined unlocking angle (zda + Ao). At the time point C, the regulating pulse 15 of the converter 6 is supplied with a pulse of control with an adjustable unlocking angle "per, and at time t an equalizing pulse with the unlocking angle Oper-f Areg enters the converter arm 15 15. In the next half-period, shoulders 17,

5 and 22 of the converter 6 at the moment of time i, a control pulse is applied with a given unlocking angle ao, and at time 2 1 + AO, control pulses are applied to the shoulders 17, 22 of the converter 5 with a given unlocking angle (coch-ao). Respectively, at the time of the control pulse with the angle, the regression is transmitted to the arm 16 of the converter 5, and at the moment t to the arm 16 of the converter 6 with an angle (oreh-b

5 -fAper).

In the subsequent half-periods of phase control, the specified control algorithm is preserved, with the values of To and Areg being greater, the greater the controlling impulse

0 to 90 el. hail, and the greater the load current. In the example above, we consider the case of alternation of different-phase pulses, iodavimi on the shoulders of the same name of two parallel non-transducers.

5 However, the proposed control method is applicable for an arbitrarily large number of parallel operating transducers. The number of like pulses that differ from each other in phase

0 by some value A, equal to the number of converters.

The implementation of the proposed method makes it possible to reduce the influence of psophometric currents on communication lines, automatic

locomotive signaling, as well as reducing the number of control zones of rectified nanograms and, as a result, simplifies the operation algorithm of the control equipment, increases the reliability of the electric drive and reduces its cost.

Claims (3)

1. A method of controlling parallel static converters, each of which is connected to a sectioned transformer having several control zones, by applying control pulses to the control angle and load current, and to the thyristors of the previous zone of all parallel converters control pulses with a predetermined unlocking angle are supplied , and on the thyristors of the subsequent zone - with an adjustable unlocking angle, characterized in that, in order to reduce psofometric currents, the time shift is each other no control pulses controlling the different zones of similar converters. 2. A method according to claim 1, characterized in that the angles of unlocking zones of the same name periodically mutually change, with the smallest angle of the previous zone corresponding to the smallest angle of the subsequent zone and vice versa. 3. The method according to paragraphs. 1 and 2, characterized in that, as a function of the control angle and the magnitude of the load current, the phase difference between the control pulses of the same name is additionally changed. Sources of information taken into account in the examination 1. Lozanovsky A. L. and others. Testing of an AC alternating current thyristor type VL80R. Electrical Engineering, № 2, 1970. ; - - / g - P