SU987741A1 - Device for protecting bridge gate-type converter - Google Patents

Description

(5Y DEVICE FOR PROTECTION OF THE BRIDGE VENTILATION.

1 The invention relates to electrical engineering and can be applied in protection devices for valve converters.

A device for protecting a bridge thyristor converter, contains; A common three-pole circuit breaker connected between the mains and the converter, and a unit for simultaneously turning off the thyristors of the rectifying group of the converter tl.

A disadvantage of the known device is low reliability, due to the complexity of the device and the fact that the protection is activated after an overvoltage has already occurred on the control valve.

The closest to the proposed technical essence and the achieved effect is a device to protect the bridge valve CONVERTER

a converter containing a three-pole automatic circuit breaker designed to be connected between the power source and the converter, the anticipated signal contact of which is connected to the same input of the And element connected by the output through the simultaneous switch-on unit to the control switch Q of the cathode valve group of the C2 converter.

A disadvantage of the known device is also low reliability. j The purpose of the invention is to increase reliability by reducing internal overvoltages.

Claims (2)

The goal is achieved by the fact that the device is equipped with a delay element and a disconnected sensor disconnected sensor, the disconnected sensor disconnecting sensor through the delay element connected to another input of element I. The drawing shows a circuit diagram for protection of the bridged vent converter. The device for protection of the converter valve, consisting of cathode valves 1,2 and 3 and anode l, 5 and 6 groups, contains a three-pole circuit breaker 7 connected between the power supply and the valve converter. The preemptive signaling contact 8 of the automatic switch is connected to one input of the element AND 9 to the OTHER input of which, through the element 1 of the delay, the sensor 11 of the disabled state of the automatic bypass is connected -; The output of the element 9 through the block 12 at the same time turning on the valves is connected to the control transitions of the valves of the cathode group of the valve converter, which output is connected to the inductive load 13. The device works as follows. In the closed state of the automatic switch 7, the preemptive signal contact 8 is open, so a logical zero is present at the corresponding input of the And 9 element. At the other input of the element And 9 from the output of the sensor 11 which is disconnected from either the automatic switch, there is a logical unit. When the circuit breaker 7 opens, before the power contacts break and before the overvoltage due to inductive load 13 occurs, contact 8 is closed. Logical units arrive at both inputs of the And 9 element. As a result, the simultaneous switching on unit 12 is actuated and supplies a control pulse to the valves of the cathode group 1, 2 and 3. Gates 1, 2 and 3 are unlocked, and the energy stored in inductive load 13 when the power contacts of the circuit breaker 7 are opened, is discharged through one of the open valves of the cathode group 1 1, 2 or 3 of the anode group that is at that time open state. The duration of the simultaneous arrival of logical units at both inputs of the AND 9 element is determined by the length of the delay of the delay element 10. Thus, the device provides reliable discharge of electromagnetic energy stored in the load, while eliminating the occurrence of overvoltages on the valve elements when the inductive load is disconnected. The application of the invention allows to increase the reliability of protection of the valve converter against overvoltages arising when the inductive load is disconnected. Claim device A device for protecting a bridge of a valve converter containing a three-pole circuit breaker for connecting between a power source and a converter, the anticipatory signal contact of which is connected to one input of an I element connected through a block of simultaneous switching of valves to cathode-to-valve control transitions A converter that is distinguished by the fact that, in order to increase reliability by reducing internal overvoltages, it is equipped with th delay and the OFF state sensor or said breaker. the sensor of the disconnected state of the circuit breaker is connected via a delay element to another input of the element I. Sources of information taken into account during the examination 1. V. Barsky Separate control of reversible thyristor converters. M., Energie, 1973, p. 105-107, fig. 3-5 2. USSR author's certificate for application number 2981736/2-07, cl. H 02 H 7/12, 1979. And in C