SU1511831A1 - Method and apparatus for switching over control windings of reactor - Google Patents

Abstract

The invention relates to electrical engineering. The aim of the invention is to increase reliability and efficiency. The goal is achieved due to a significant limitation of the volumetric charge recovery when the semiconductor switch is closed and, accordingly, the restoring voltage. The effect of limiting overvoltage is achieved by choosing the time period (phase) of the applied alternating voltage separately for connecting and disconnecting the control winding without using additional protective elements. For this purpose, a switching pulse shaper 16 is inserted into the device for switching the control windings of the reactor, generating at its outputs pulses that are out of phase by 0.9 - 0.92ϕ + ϕK and 0.99 - 1.01ϕ + ϕK, where K = 1 , 2,3 ..., switching pulses selection unit 15, controlling D-triggers 11,12,13, depending on the initial state of the switches and the required combination of switching on the control windings set by the distributor-encoder 14. 2 cps f-ly, 1 ill.

Description

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respectively, the restoring stress. The effect of limiting overvoltage is achieved by selecting the time period (phase) of the applied alternating voltage separately for the case of connecting and disconnecting the control winding without using additional protective elements. For this purpose, a shaper 16 switching pulses are introduced into the device for switching the control windings of the reactor, producing at their outputs pulses that are phase-shifted by 0.9-0.92 G + nK and by 0.99 i, where, 2, 3, ..., switching impulse selection unit 15, controlling i-triggers 1.1-13 depending on the initial state of the switches and the required combination of switching on the control windings, specified by the distributor-encoder 14. 2 sec., P. f-ly, 1 ill.

The invention relates to electrical engineering.

The purpose of the invention H1-w - povpepeniya reliability and efficiency.

The drawing shows a diagram of the device for switching the control windings of the reactor implementing the method.

The power supply source 1 is connected in series with the main winding 2 of the reactor and control windings 3 and 4. The leads of windings 2-4 through switches 5-7 are connected to a common point and connected to source 1, Matching blocks 8-10 are connected to control ones the electrodes of the corresponding semiconductor switches 5-7. The inputs of matching blocks 8-10 are connected to the outputs of the corresponding D-flip-flops, the information inputs of which are connected to the outputs of the distributor 14, the outputs of the D-flip-flops P-13 are also connected to the information inputs of the switching pulse selection block I5, and the large inputs of which are connected to the outputs a switching pulse generator 16, the input is connected to the output of synchronization unit 17 connected to the source 1. The bbDfs of unit 15 are connected to the C inputs of the corresponding D-flip-flops 11-13.

The device works as follows.

Suppose that in the initial state, under the action of source 1, a main current flows through the main winding 2, the control winding 3, and the closed semiconductor switch b. Switches 5 and 7 are open. The matching unit 9 generates a control voltage for the switch 6, the output of the D-flip-flop 12 has a logical unit, the output of the D-flip-flops 11 and

13 is a logical zero. On one output of the encoder-distributor 14, connected to the D-flip-flop 12, there is a logical one, on the O-outputs there are logical zeros.

The synchronization unit 17 controls the operation of the switching generator 16 and pulses, on two outputs of which in the celsome period

the voltages of source 1 are formed by short rectangular pulses with a duration of the order of 1 ms. At one output, a pulse is formed, which is shifted in phase from the moment when the alternating voltage of source 1 (the beginning of its period) passes through zero, by an angle equal to 0.9-0, and at the other output is a similarly shaped pulse, shifted in phase by angle 0.991, 011Г. .

Pulses with a phase of 0.9–0.92 arrive at the first pulse input of the switching pulses selection unit 15 and are designed to control the process of switching off the control winding windings, pulses with a phase of 0.99-1.01 G are fed to the second pulse input of the unit I5 and are intended to control the process of connecting adjusting windings. Unit 15, depending on the combination of logical signals on the information inputs, passes one specific switching pulse to its outputs. Block 15 is a type of logical device of the selector-multiplexer type.

The truth table of block 15 is as follows.

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In this case, the first output of block 15, connected to the clock input of D-flip-flop 11, receives a pulse with phase O, 9-0.927, through which this flip-flop can go to one state for subsequent closing of switch 5 and turning off the control winding 3. At the third output of the block 15 / connected to the clock input of the D-flip-flop 13, a pulse with a phase of 0.99-1.01 / iT appears, through which this flip-flop can go into one state for subsequent closing of switch 7 and connecting adjustment winding 4.

If an external control device receives a command to reduce the number of turns of the reactor, then the outputs of the encoder-distributor 14 connected to D-flip-flops 12 and 13 are set to logical zeros, and the output connected to D-flip-flop 11 is a logical one.

Upon the arrival of a switching pulse with a phase of 0.9–0.92 iT from block 15 to the clock input D of the trigger 1 1, the latter changes the logical state of its output from zero to one, and the D flip-flop 12 from one to zero. D-flip-flop 13 does not change its state, since a logical zero remains at its information input;

Thereafter, the matching unit 9 stops the supply of control voltage to the switch 6, and the matching unit 8 applies the control voltage to the switch 5. The control winding 3 is forcibly turned off at the optimal time of the applied alternating voltage period. At the same time, there is a minimum regenerative voltage on the closing switch 6.

Blocks 8-10 matching, are identical and are controlled by the generator of high-frequency pulses, which, after transformer isolation and straightening come on

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control electrodes of semiconductor (thyristor) switches.

Claims (2)

1. The method of switching the regulation windings of the reactor by semiconductor switches by feeding Q of the control signal to the switched on switches and simultaneous removal of the control signal from the disconnecting switches, characterized in that, in order to increase reliability and efficiency, the control windings are disconnected during the phase of the AC supply voltage equal to 0.9-0 , 92ir + k M, and the connection - with the phase equal to 0.990 1.01 i Hk r, where, 2,3, ... 2. A device for switching the control windings of the reactor containing the Main and control windings, the outputs of which are connected 5 through semiconductor switches to a common point, matching blocks connected to corresponding semiconductor switches, synchronization unit, distributor encoder, 30 characterized in that, in order to increase reliability and efficiency, the switching pulses selection block, three D-flip-flops and the switching driver are introduced chg of pulses, whose input is connected to the synchronization unit and has two outputs, on the first form of pulses with a phase equal to 0.9-0.92 ir + k n, and on the second - with a phase of 0.99-1, 01 lT + k, 40 where, 2, 3 ..., both of which are connected to the pulse inputs of the switching pulses selection unit, the information inputs of which are connected to the corresponding outputs 45 D-flip-flops and inputs of matching blocks, and outputs are connected to C-inputs of D-flip-flops, the information inputs of which are connected to the corresponding outputs of the distributor distributor, the input of the synchronization unit is connected to the supply voltage source. Note. Both switching impulses are output.