SU875575A1 - Device for separate control of converter with load-shunting thyristors - Google Patents

Description

The invention relates to converter technology, in particular to devices for controlling reversible valve converters.

A device for controlling reversing converters is known, which is applicable only to single-channel asynchronous control systems [1].

The closest in technical essence is a logical switching device for a reversible controlled transducer containing triggers, a current sensor, a coincidence element, a delay element 12].

The device is designed to reduce the pause for switching valve groups, if in intermittent current mode the latter changes direction before the time delay ends.

However, this device does not provide a reliable ban on the inclusion of a previously not working group of valves during reverse.

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

This goal is achieved in that the device for separate control of the converter with shunting thyristors is equipped with a sensor of a given current direction and two AND-OR elements, and the outputs of a sensor of a given current direction are connected respectively to the information input of the trigger and the first input of the comparison element, the second and third the inputs of which are connected to the outputs of the trigger, and the output to the input of the current presence sensor, the first output of the current presence sensor is connected to the input of the delay element, the first output is It is connected to the trigger input of the trigger, the first outputs of the current sensor and the delay element are connected to the two inputs of the first group of inputs of both AND-OR elements, the two inputs of the second group of inputs are connected to the second outputs of the delay element and the current sensor, third inputs of the current side , the third inputs of both groups of inputs of AND-OR elements are connected to the corresponding outputs of the trigger.

^J 875575

The drawing shows a schematic diagram of the proposed device.

The device comprises a sensor 1 of a given direction of current, a sensor 2 for the presence of current, a delay element 3, the output of which a signal appears with a delay time, and disappears instantly, trigger 4, AND-OR elements 5 and 6, coincidence element 7. The outputs of the AND-OR elements 5 and 6 are the outputs of the device.

The device operates as follows.

If there is a signal “1” at the output of element 5 or at the output of element 6, the supply of control pulses to the corresponding group of power valves is allowed. With po4, the value not original changes, the signal “0” is generated at the output of the coincidence element 7, prohibiting the passage of signals from the current sensor 2, the _5th time delay countdown is stopped and the control pulses are allowed to pass to the previously operating converter group.

Thus, the device allows you to quench the residual energy in the load with shunt valves, thereby speeding up the process of locking all the valves of the outgoing group, blocks the inclusion of another group of valves for this time, which increases the reliability of the device as a whole.

the phenomenon at the outputs of these signal elements <”0” the control pulses of the corresponding ’group are blocked.

When changing the signal of the sensor 1 of a given direction. current at the output of the element 7 matches the signal is formed "1", which _2C allows the passage of the signal from the sensor 2 of the presence of current to its output. After the converter current drops to zero, the signal “1” appears at the first output of the current presence sensor 2. Changing the signals of the current sensor 2? ₅ leads to the appearance of signals “0” at the outputs of elements 5 and b, which block the supply of pulses to both groups of valves and, at the same time, the delay time starts counting by element 3. After the time delay has passed, the trigger 4 switches over the signal of the time delay element 3 and at the output of the device, an enable signal is generated for passing control pulses to the converter valve group that enters into operation, at the same time, coincidence element 7 blocks the current presence sensor 2.

If during the countdown of the time delay with a constant signal of the sensor 1 for setting the current, the signal of the sensor 2 for the presence of current (the current appears in the power circuit), the countdown of the time delay <0 k stops and instantaneous passage of control pulses to the previously working group of valves of the converter is allowed. Since the control pulses are received by a group that has not previously worked, then the load current decreases rapidly due to the invert mode.

If, during the endurance count, the signal of sensor 1 of a given direction, the current again

Claims (2)

The invention relates to a converter technique, in particular, devices for controlling reversible valve converters. A device for controlling reversing converters is known, which is applicable only to single-channel asynchronous control systems 11. The closest in technical essence is a logical switching device for a reversible controlled converter containing triggers, current presence sensor, coincidence element, delay element 12 The device is intended for reduce the voltage on switching valve groups, if in the current-current mode the latter changes, the direction is earlier than the time delay and. However, this device does not provide a reliable ban on the inclusion of a previously not working group of valves during the reverse. The purpose of the invention is to increase the reliability of the device. This goal is achieved by the fact that a device for separate zavavleniyu converter with load-bypass thyristors, is equipped with a sensor of a given current direction and two AND-OR elements, and the outputs of the sensor of a given current direction are connected respectively to the information input of the trigger, the second and third whose inputs are connected to the trigger outputs and the output to the current presence sensor input, the first current presence sensor output is connected to the input of the delay element, the first cat output The op is connected to the trigger clock input, the first outputs of the current presence sensor and the delay element are connected to two inputs of the first group of inputs of both AND-OR elements, two inputs of the second group of inputs of which are connected to the second outputs of the control element and the current presence sensor, the third inputs of the sill the presence of current, the third inputs of both groups of inputs of the elements AND-OR are connected to the corresponding outputs of the trigger. The drawing shows the initial scheme of the device. The device contains a current direction sensor 1, a current presence sensor 2, a delay element 3 at the output of which the signal appears with a time delay, and instantly disappears, a trigger 4, AND-OR elements 5 and 6, a coincidence element 7. The outputs of the elements AND-OR 5 and 6 are the outputs of the device. The device works as follows. If there is a signal 1 at the output of the element 5 shsh at the output of the element 6, the supply of control pulses to the corresponding group of power gates is allowed. When the output of these elements of the signal O appears, the control pulses of the corresponding group are blocked. When the signal of the sensor 1 of a given direction changes, the current at the output of the coincidence element 7 generates a signal 1, which permits the passage of the signal of the sensor 2 in the presence of current to its output. After the current (of the forge generator reaches zero), signal 1 appears at the first output of current sensor 2. Changing the signals of current sensor 2 causes current O, at the outputs of elements 5 and b, which are blocked from the supply of pulses to both groups of valves and about The time delay starts counting by element 3. When the time delay expires, the signal of time delay element 3 {switching of trigger 4 takes place and an output signal is generated at the output of the device for control pulses to go into operation. uppu valves transducer odaovremenno element 7 sovpadeshsh blocks 2 presence sensor current. If during the time delay countdown with a constant signal of the current setting sensor 1 changed the error of the current sensor 2 (through the current in the power circuit), the time delay countdown stops and control pulses are immediately passed to the previously operating group of converter gates. Since the control pulses do not come from a previously operating group, an intensive decrease in the load current beyond the inversion mode occurs. If, during the exposure time, the signal of the sensor 1 of the specified direction, the current again does not change its value, the output signal 7 produces a signal O that inhibits the passage of signals from the current sensor 2, stops time delay and the control pulses are allowed to pass previously working group converter. Thus, the device allows to quench the residual energy in the load with shunt valves, thereby accelerating the process of locking all the valves of the group out of operation, blocking the inclusion of another group of valves at this time, which increases the reliability of the device as a whole. Formula of Invention groups of inputs, the outputs of the sensor of a given current direction are connected respectively to the information input of the trigger and the first input of the coincidence element, the second and third inputs of which are connected to the output am trigger, and the output - to the input of the current presence sensor, the first output of the current availability sensor is connected to the input of the delay element, the first output of which is connected to the trigger input of the trigger, the first outputs of the current availability sensor of the delay element are connected to two inputs of the first group of inputs of both I- elements OR, two inputs of the second group of inputs of which are connected to the second outputs of the current presence sensors and the delay element, the third inputs of both groups of inputs of the AND-OR elements are connected to the corresponding outputs of the trigger. Sources of information taken into account during the examination 1. USSR author's certificate W 6S6161, cl; H 02 M 1/08, 1977. 2. Authors certificate of the USSR N 513456, cl. H 02 M 1/08, 1974.