SU1626309A1 - Device for controlling reversible valve-type converter - Google Patents

Abstract

The invention relates to electrical engineering and can be used in converter equipment and in a thyristor electric drive. The purpose of the invention is to increase the reliability of work. The device for controlling the reversible vertical converter contains a block 1 time

Description

J

Os Yu O 00

eight

individual operation of valve groups and two identical control units: unit 2 controls the valve group Back converter and unit 3 controls the valve group Forward. Each of these control units 2, 3 incorporates a phase shifting unit 4. Block 4 is connected to the output of block 1 of separate operation of valve groups. The number of outputs of block 4 is equal to the number of phase shift channels. The outputs of block 4 are connected to the inputs of output switches 5, represented in the drawing in the form of transistors. Transistor collectors

The invention relates to electrical engineering and can be used in conversion techniques and thyristor electric drives.

The purpose of the invention is to increase the reliability of operation.

The drawing shows a functional diagram of a device for controlling a reversible valve converter.

The device contains a unit of separate operation of valve groups and two identical structural units: unit 2 controls the valve group Back converter and block 3 controls the ventilation group Forward. Each of these blocks 2 and 3 incorporates a block 4 phase shift. to the input of which is connected the corresponding output of the unit 1 separate work of valve groups. The outputs of the phase shifting unit 4, the number of which is equal to the number of phase shifting channels, are connected to the corresponding inputs of the output switches of the 5 phase shifting channels represented as transistors. The collectors of each of the transistors of the output switches 5 of the phase shifting channels are connected to the beginning of the respective primary windings 6 of the transformer potential dividers (the secondary windings of the potential dividers are not shown) and through the corresponding diodes of the diode assembly 7 to the thyristor cathode 8, and the diodes of the diode diodes 8 are connected assemblies 7, the number of which is equal to the number of phase shift channels of both groups. The ends of the primary windings 6 are connected to the outputs of keys 9 and 10. As keys 9 and 10, in order to improve noise immunity, it is recommended to use optocoupler thyristors. The inputs of the keys 9 and 10 of the groups Back and Forward are connected through a fuse 11 to the common for both groups emitted from the beginning of the corresponding primary windings of 6 potential transformer isolators. The emitters of the transistors of both groups are combined and connected to the negative pole of the power supply 12 common to both groups of the converter. The ends of the windings 6 are connected to keys 9, 10 groups Back and Forward1 The device also has a fuse 11 and a thyristor 8 common to both valve groups. The two control circuits are unlocked using diode assemblies 7. 1 sludge.

Nick 12 of the power supply, to its positive pole, and the negative pole is connected to the emitters of the transistors of the output switches 5 of both groups. The control input of the switch 9 is connected to the corresponding output of the unit 1 of the separate operation of valve groups. The control electrode of the thyristor 8 through a resistor 13 is connected to the output of the key 10 of the valve control unit 3 of the Forward group. The anode of the thyristor 8 is connected to the output of the key 9 of the control unit 2 of the valve group Back.

The operation of the control device of the reversing valve converter is carried out as follows.

The output keys 5 of the phase offset channels are controlled by the program of the phase shifting blocks 4 and the separate operation unit 1 of the valve groups with signals an and av, namely, the moment of arrival of the control pulse is determined by the required control law of the output parameter (signal a) at the input of the phase shifting blocks 4 and the polarity required converter voltage (signal is is at the input of block 1 of separate operation of groups, the latter being blocked by the current sensor signal i).

The keys 9 and 10 are controlled by the program of the unit 1 of the separate operation of valve groups with iH signals and: they are open during the period of operation of the valve group and are closed in an inoperative valve group, and the server program provides that all keys are turned off for the time of the currentless pause of the converter when switching groups Forward and Back.

After the end of the dead time, the enable signal of the block 1 of separate work of valve groups comes, for example, to the control input of the key 9 of the block 2 of the control of the valve group Back of the converter. The key 9 is unlocked and connects the power to the potential dividers of the backward group of ventilators. At the same time, the key 10 of another valve group is closed, and even if the output keys 5 of the valve control unit 3 of the Forward group of the converter receive an enable signal caused by interference, it will still not be transmitted to the potential separators of the Forward group, since at the moment their power is off.

If it is necessary to carry out a reverse, the unit 1 of separate operation of valve groups will stop the supply of the enable signal to the elements of the unit 2 of the control group of the valve group Back converter. Since the control signal is pulsed in nature, at a certain moment the current through the switch 9 is interrupted and it is prohibited.

If, as a result of the interference, keys 9 and 10 of both groups are simultaneously opened, this creates the conditions for unlocking the thyristor 8, since an enabling signal will be sent to its control electrode through resistor 13. However, since all the output switches 5 will be closed, the current will not flow through the thyristor 3 and the converter will be able to continue trouble-free operation if the interference disappears. If with open keys 9 and 10 of both groups any output switch 5 is opened, then the current to the winding 6 of the transformer potential separator will not flow, but will be closed through the thyristor 8 and the corresponding diode of the diode assembly 7, which is determined by a higher speed the current builds up through the thyristor 8 and the diode than through the winding 6 of the transformer potential separator due to the inductive properties of the latter. At a certain current value, the fuse will operate 11.

Claims (1)

Apparatus of the Invention A device for controlling a reversible valve converter consisting of two valve groups, containing a separate operation group of valve groups, connected to electrical displacement units, coaxial outputs are connected to the output switches of phase-shifted channels connected to the first terminals of potential transformer potential windings. separators, the second terminals of which through the first and second keys are combined and connected via a fuse to a DC power source, characterized in that. that, in order to increase reliability, it is equipped with a thyristor, the anode of which is connected to the output of the first key, the control eeptrsd through a resistor is connected to the output of the second key, and the cathode is connected to the anodes of the additional diodes by the offset of both valve groups, the cathode of each diode connected to the first terminals of the potential transformer primary windings separators.