SU851741A1 - Method of negulating valve-type converter - Google Patents

Description

(54) METHOD FOR REGULATING VENTILATING CURRENT CONVERTER

I

The invention relates to electrical engineering, in particular, to methods of regulating valve converters, direct current transmissions and direct current inserts.

Known methods for regulating the current of valve converters are based on controlling the phase of control pulses in the range with upper and lower limits of limitation, which are the basis for the implementation of control systems for valve converters in which the control zone is strictly limited regardless of the magnitude of the alarm current. converter The upper limit of the limiting zone is set according to the condition of the converter (rectifier) in the inverter mode with an unregulated extinction angle l and 2.

Closest to the proposed method of regulating the current of a valve converter, in which the converter current is compared with the set and according to the result;

Comparison tattoos change the valve control angle in the range with upper and lower limit limits, and the upper limit value is additionally changed depending on the measured current: when the current rises to a suitable value corresponding to the upper limit of the control angle, the upper limit decreases adjustment limit up to the required intermediate value of 3j.

The disadvantage of the known method is that in the case of a significant rate of increase of the controlled current, the next switch may not be successful if the regulation of the upper limit of the zone is made only after the controlled current reaches the specified acceptable value, resulting in qjbm

20 bridge converter.

The purpose of the invention is to increase the switching SUSTAINABILITY of the valve preformer in transient modes, accompanied by significant speeds of the accumulated current at any time point of its change.

This goal is achieved by the fact that the decrease in the value of the upper limit of the limit within the interval of its regulation is additionally made with a lead that depends on the rate of growth of the current when it exceeds a certain predetermined value. As a result of anticipation, if the slew rate of the current exceeds a predetermined amount, an additional effect is generated, depending on the magnitude of the indicated speed, by reducing the specified limit, which ensures the success of the next commutation of the converter.

Fig, 1 isofazheno device for the implementation of the proposed method; in fig. 2 - diagrams explaining his work.

The valve converter 1 is alphabetized from a control system 2 consisting of a generator of 3 synchronizing pulses, a block 4 forming a zone of limiting the phase of the control pulses and a block 5 controlling the phase of the control pulses to which the control signal is applied

The auxiliary control input of the zone formation unit is connected to the output of the adder 6 ,. one input of which is coi | Dinen with the output of functional converter 7, and the second with block 8 of the derivative. At this, the first inputs of the last two blocks are given respectively to the setpoint parameters Eab and to the second inputs - a signal that is projective for current 3 in line 9 from current sensor 1O.

The device operates as follows.

From the voltage UQ of the converter supplying 1, the synchrose pulses are generated by the generator, corresponding to the lower limit of the limiting zone, which is formed by using the former 4 of the limiting zones of the control pulse phases. A signal corresponding to this zone is fed to the control pulse phase control unit 5, from the output of which the control pulses are fed to the control electrodes of the converter valves.

With an increase in the current in the line of a given value of p, the functional converter 7 produces a screenal effect through the adder 6 on the driver 4 of the control pulse phase limiting phase, which changes its upper limit 11 when the current reaches the specified Ozaa value.

However, at sufficiently high current rise rates, despite the fact that the current has not reached a given J-jcj value, switching may not be successful.

FIG. 2 shows the current switching of converter 1 with a rapid increase in current. Although at the Time t, which determines the intermediate upper limit of the pulse phase, the current did not reach the specified value. Ezod ° mutation is unsuccessful due to a lack of angle caused by an excessively fast current incrementing factor. From FIG. 2a, it is seen that the next control pulse is applied at the instant of -b2, and not at the instant of fc, at which there is an additional margin of extinction, corresponding to an increase in the ignition advance angle by the value of it -fca.

To prevent tilting the converter, an additional block 8 is introduced in production, which, if the current rise rate is exceeded, generates an additional signal (figure 2) acting on the upper limit of the limiter 4 zones through the adder 6. Thus, it is possible to increase the forward angle of the next valve, despite the fact that the current value in LINE has not yet reached the specified value.

FIG. 2c shows the process of successful switching when an additional signal is applied in terms of the rate of increase of the current exceeding the speed setpoint (). In this case, the supply of the next pulse coincides with the limit of the specified intermediate limit limit.

The implementation of the proposed method on transmissions and DC inserts allows for optimal regulation of the current in transients without the appearance of overcurrents and to keep the converter in operation during the appearance of supercurrents growing at significant speeds and thereby prevent the emergency mode from declining. his works.

Claims (1)

Invention Formula The method of regulating the current of the valve converter by reducing the AlAmbibi upper limit of the limitation of the zone of change of the phase of the control pulses I with an increase in the controlled current, probably because, with the aim of controlling the resistance of the converter, they measure the current rise in the junction shaft above some predetermined magnitudes decrease in proportion to the magnitude of the upper limit of the limits in the adjustment intervals. Sources of information taken into account during the examination 65 16 1. Unified the management system for valve pre-phaseters MV. . (Zvste we uflavleni tristornymi vonnye electric drives. VNIIEM. Informele ktro, M. 1971, p. 54. 2, Combined regsshttor tsnsa for the transfer of posts of ganogo current Volgograd-DSn bass, Lime NIIPT, 1962, 9, p. 86 3. USSR author's certificate in accordance with the application M 2615814 / O7, class Q 05 F l / bil, H 02 R 13/16, 1978 (prototype). ","