SU758464A1 - Method of single-channel control of power-diode converter - Google Patents

Description

(54) METHOD FOR SINGLE-CHANNEL CONTROL OF VENTILATION CONVERTER

one

This invention relates to power conversion technology and can be used in valve converters with natural switching of valves, rectifiers, slave inverters, reversible converters and direct frequency converters.

The known method of single-channel control by a converter, by which the mains voltage of all phases is filtered, segments are separated from the filtered voltage, the beginning and end of which are limited to the generation of corrective pulses, and these segments are compared with the control voltage; when the voltages are equal, control pulses 1, 12 are generated. The formation of the reference voltage from the network voltage is possible only with high quality of the network voltage, since otherwise when filtering distortions a large phase error is introduced in the determination of the control angle. This limits the scope of application of the device.

The closest in technical essence to the present invention is a control method.

consisting in forming linearly varying voltage and constant voltage, taking normalized values, summing up linearly varying, controlling and constant voltage, fixing the equality of their sum to zero and at the same time, as well as at the end of the forward stroke linearly varying voltages vary the value of the constant voltage 3.

However, in this method when forming

10 reverse stroke of a linearly varying voltage, the device may be falsely triggered, i.e. generating a false control pulse. This reduces the reliability of devices that implement this method.

15

The aim of the invention is to increase reliability.

Claims (3)

For this, according to the proposed method, linearly varying voltage and constant voltage are formed, taking normalized values, summing up linearly varying, controlling and constant stresses, fixing their sum to zero and the completion of linear motion of linearly varying voltage if the sum of the indicated voltages is equal to zero, a control pulse is formed and the value of the constant voltage is changed, and at the end of the forward stroke the linearly varying voltage also changes the value of the constant voltage . In this case, a change in the value of a constant voltage at the completion of the forward stroke of a linearly varying voltage is delayed by a time equal to the duration of the reverse stroke of the indicated voltage. FIG. 1 shows a block diagram of a device implementing the proposed method; in fig. 2 - time diagrams. Control voltage generator 1, linear voltage generator 2 and constant voltage source 3 are connected via adder 4 to a null organ 5, at the output of which control switch-generator 6 is connected. clock pulses 7, the output of which through the delay circuit 8 is connected to the control input of source 3. The latter is also connected to the output of the null organ 5. In FIG. 2, diagrams 9 and 10 relate to the prototype, diagrams 11 and 12 to the proposed method; Diagrams 9 and I show linearly varying voltages, diagrams 10 and 12 show the sum of linearly varying and constant voltages, as well as the control voltage of the converter. The principle of operation of the device implementing the proposed method favorably differs from the prototype. If in a known device, in the presence of a linearly varying voltage reverse (diagrams 9 and 10), the sum of the linearly variable and constant voltages has a surge directed towards the control voltage, which may cause a false zero-body response 5 then, according to the proposed method, the surge is directed in the opposite direction, since first the reverse occurs, and then the constant voltage switches. False tripping is not possible. If the equality of the voltages at the input of the zero-body 5 coincides with the moment of the return stroke, then the generation of the control pulse will be delayed for the duration of the return stroke 7 44. Does the} linearly varying voltage. B1 exclusion of non-linearity of the control characteristic, the duration of the reverse stroke must be within the accuracy of setting the control angle, which is realized by appropriate selection of the generator of linearly varying voltage 2. Thus, the proposed method allows to increase the reliability of the single-channel control systems by eliminating the possibility of false positive system. Thus, the advantages of this class of single-channel control systems are realized: high symmetry of control pulses, speed, linearity of adjusting properties, the ability to function when there is distortion in the network, compactness of hardware implementation by means of microelectronics. Claims The method of single-channel control of a valve converter, which consists in forming linearly varying voltage and constant voltage of a normalized value, summarizes the linearly varying, control and constant voltage, fixes their sum to zero and terminating the direct voltage. the course of a linearly varying voltage, when the specified sum is equal to zero, a control pulse is formed and the value of the direct voltage is changed, and at the end of the forward stroke the linearly varying voltage kzhe alter the magnitude ngo constant voltage, characterized in that, in order to increase reliability, the variation of DC voltage at the completion of the forward stroke of linearly varying voltage is delayed by a time equal to the duration of said flyback voltage. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 547962, cl. H 02 R 13/16, 1975. 2. USSR author's certificate number 547963, cl. H 02 B 13/16, 1978. 3. USSR author's certificate number 586539, cl. H 02 R 13/16, 1976 (prototype).