SU1422322A2 - Logical switching device for reversible controlled rectifier - Google Patents

Abstract

The invention relates to power converter technology, in particular, to control devices for ventilating and tilting converters, which can be used in a thyristor electric drive. The purpose of the invention is to increase the reliability of the drive. The device contains sensors of a given and true directions of current 1, 2, to the outputs of which a trigger of a given direction of current 5 and an element OR 4 are connected. The outputs of the elements AND-NE 6-8 are the outputs of the device. Speed sensor 11 is connected to dead time element 9 via nonlinear link with deadband 10. As motor speed increases or decreases, nonlinear link with deadband 10 outputs to the auxiliary input of time delay 9 signal at which the value of dead time increases or decreases. by leap. 1 il. L

Description

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The invention relates to power converter technology, in particular, to control devices for valve converters, and is an improvement of the device according to author. No. 513456.

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

The time delay of the dead time when operating at high speeds of the electric drive is increased to increase reliability.

The drawing is a diagram of the proposed device.

A logical switching device for a reversible controlled rectifier contains sensors i and 2 of the specified and true current direction, the outputs of which are connected to the trigger 3 of the specified current direction and the element OR 4, the trigger 5 of the true direction of the current, the inputs of which are connected to the forward output of the trigger 3 and to the output of the element 4, and the outputs - 25 to the inputs of the elements AND-NOT 6 and 7, the second inputs of which are connected to the corresponding outputs of the trigger 3 of a given current direction, and the outputs to the second input of the element OR 4 through the element IS-NOT 30 8 and ale A time 9, the auxiliary input of which is connected to the output of the speed (frequency) sensor 11 via a nonlinear link 10 with a non-sensitive zone. The outputs of the AND-NE elements 6-8 forming a coincidence circuit are the outputs of the device.

The device works as follows.

If there is a signal on the output

12 (output of element 6) or at the exit

13 (output of element 7), the supply of control pulses to the corresponding power sets of the Forward or Backward direction valve is allowed. ., The appearance at these outputs of signal 1

means prohibiting the issuance of control pulses to the corresponding sets. The signal 1 from the output of element 8 is used as a signal for the permission of the pulses to be output by the system of pulse-phase control. The signal O at this output, appearing when the position of the trigger 3 does not correspond to the position of the trigger 5, prohibits the issuance of pulses to any of the power sets of the rectifier. I

Both triggers are blocked from being switched by signal 1 from sensor 2

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presence of current. In addition, trigger 5 is prevented from being switched by signal 1 from the output of time lag element 9.

When the current setpoint changes, the trigger 3 switches to a new position only if the current does not exist in the power circuit. In this case, due to the incompatibility of the triggers 3 and 5 at outputs 12 and 13, a signal 1 appears, which leads to the removal of control pulses from the previously operated 5 sets of valves and the appearance of the signal O at the output of element 8. This leads to that time delay element 9 begins counting the time delay, after which an O signal also appears at its output. This removes the prohibition on switching of the trigger 5, if during the time delay time does not follow the current in the power circuit. Trigger 5 switches to the position corresponding to the position of trigger 3. Control valves are applied to the valves of the previously not working power set, signals 1 appear at the outputs of elements 8 and 9. 3 instantly returns to the previous state, and the signal O at the output 12 (13) connects the control pulses to the power supply valve previously operated without time delay. At the same time, signal 1 from the output of element 8 instantly returns element 9 to the initial state on the same connection, i.e. At its output, a signal 1 appears, blocking the trigger 5 from switching.

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With increasing speed (EMF) of the engine with the nominal value 0.8 of the nominal value, the nonlinear link 10 sends to the additional input of the time delay element 9 a signal 1, by which the dead time increases in steps. At. decreasing the speed below 0.8 of the nominal value at the output of the threshold element 10, signal O, respectively, abruptly reduces the value of the dead time to a value sufficient to ensure reliable operation of the electric drive at speeds below 0.8 of the nominal value.

31422322

Claims (1)

The invention of speed, non-linear link with a zone insensitivity The logic switching device is provided with an additional input for the reversible controlled house, and the output of the speed sensor of the rectifier is auth.t. No. 513456, is connected via a non-linear link, characterized in that, with a non-sensitive zone to additionally, in order to improve the reliability of the electrical input of the drive's holding element, a time sensor is inserted into the device.