SU532169A1 - Self-tuning switching device - Google Patents

Description

one

The invention relates to the field of electrical engineering, namely, devices for switching valve groups of reversible converters with separate control.

Switching devices are known that are used in separate control systems of reversible valve locators 1 and 2. However, these devices are complex and not reliable enough.

It is also known a switching device with self-tuning, containing a current sensor of a valve soil of a reversible converter, symmetric potential triggers made on transistors, delay elements made on the basis of passive / C-circuits and connected between the outputs of the triggers, transistor controlled keys, through which the inputs of the first trigger connected to the current sensor, and the keys control inputs are connected to the outputs of the second trigger, two diode OR circuits, the inputs of each of which are connected to the same outputs boih triggers, and bootstrap node, which is a transistorized multivibrator transformer output. The timing of the multivibrator drive is made on a transformer with a rectangular hysteresis loop. The time of magnetization reversal of the transformer from one saturation state to another is

half period oscillation frequency of the multivibrator. The positive feedbacks of the multivibrator are closed through transistor controlled switches connected to the current sensor. The output node of the self-tuning is connected to the inputs of the first trigger 3.

In the absence of a current sensor signal, the self-tuning node operates in a self-oscillating mode. With the frequency of oscillation of the multivibrator, trigger inputs are alternately fed to the inputs of the first trigger.

If a signal at the output of the current sensor appears during a pause, then simultaneously with the breakdown of oscillations of the multivibrator (the signal at its output disappears), this signal passes through one of the keys to the center of the first trigger and returns it to the state that existed before switching. The previously operated venous group is re-enabled.

 A special node self-tuning, which includes multivibrators, delay elements and keys, complicates the known device and increases the complexity of the work on its adjustment and tuning.

To simplify the proposed device, delay elements are included between the inputs of the first and the outputs of the second flip-flops.

The 4epTeHve is given the block diagram described by ycTpoiicTBa.

The device contains a sensor 1 of the current of the valve groups of the reversing converter, cP1mmetric potential triggers 2 and 3, made on transistors, two pairs of delay elements 4 and 5, 6 and 7, made on the basis of passive U C-circuits, of which the first pair is connected between the trigger outputs 2 and the trigger inputs 3, and the second pair between the outputs of the trigger 3 and the inputs of the trigger 2, transistor controlled keys 8 and 9, through which the trigger inputs 2 are connected to the current sensor, and the control inputs of the keys 8 and 9 are connected to the outputs of the trigger 3, diode circuit we are OR 10 and 11 whose inputs are connected to the same outputs of the flip-flops 2 and 3. The outputs of the OR circuits are the outputs of the switching device.

If the converter's valve groups are de-energized, then there is no signal at the current sensor output.

The device operates in a self-oscillating mode alternately with intervals of time equal to the value of the dead time, giving the command to turn on the first and second valve groups. The initial state of the device is taken by the position of the flip-flops 2 and 3, when pa their outputs 12 and 13 have signals that go to the inputs of the circuit OR 10. The prohibition signal from the output of the circuit OR 10 goes to the gate group A. With a delay determined delay element 6, the signal from the output 13 of the trigger 3 is fed to the input 14 of the trigger 2, after which the trigger 2 overturns. At its output 12, the signal disappears, and at output 15 it appears. This signal, passing through the OR circuit, and imposes a ban on the operation of the valve group 13. At the same time, the signal from the output 15 of the flip-flop 2 is fed to the input of the delay element 5, the delay time of which is equal to the required dead time. After a time delay, the signal passes to the input 16 of the flip-flop 3, as a result of which the flip-flop 3 is tilted. At its output 13, the signal disappears, and at output 17 it appears. At the output of the circuit OR 10, the signal disappears. Turn on valve group A is allowed.

If there is no current in the valve group A (no reference signal), then through the delay time of the delay element 7, the output 17 of the flip-flop 3 passes to the input 18 of the flip-flop 2 and the operation of the switching device in the second half-period of self-oscillations proceeds similarly. The operation of the device is cyclically repeated. In this mode, keys 8 and 9 are alternately opened by signals from outputs 13 and 17 of trigger 3, however, due to the absence of a signal from sensor 1, current does not affect the operation of the device.

At the current of the converter, a signal is generated at the output of the current sensor 1, which passes through the public key 9 (8) on the input 18 (14) of the trigger 2.

The current sensor signal has a polarity opposite in sign, and the value is slightly larger than the signal from delay element 7 (6). This eliminates the effect of the signal from delay element 7 (b) on the state of trigger 2. Self-tuning

the device, i.e. the search for the state of the circuit uniquely corresponding to the valve group conducting current, is completed. In this state, the device remains for an arbitrarily long time, right up to the moment when, when reversed

or reducing the converter current to zero, the signal from the output of current sensor 1 will disappear.

The signal from delay element 7 then acts on trigger 2, which is tilted. There is no signal from its output 12

pa of the input of the circuit OR 10. A ban is imposed on both valve groups on the dead time, determined by the delay time of the delay element element 4. If during a pause at the output of sensor 1

A current signal appears (which is possible when the current increases in the pause due to a sudden change in the motor emf, for example, when the engine is seized, when the network voltage drops sharply and the converter is in the inverter mode; etc.), then this signal passes from the hidden key 9 to the input 18 of the trigger 2. Since the signal of the current sensor exceeds the signal from the delay element 7 and

opposite to its sign, trigger 2 returns to the state before its switch. The signal at its output 12 disappears, the timing of the delay element 4 is stopped, the device returns to its previous state, and the previously working capillary group A is turned on. Such an embodiment of the proposed device allows refusing a complicated special self-tuning node, as a result of

which simplifies the design of the device and reduces the complexity of the work of setting it up and setting it up.

Claims (3)

1.Avt. CD. No. 306533, cl. H 02M 1/08, H 02P 13/16, 1970. 2. Avt. St. To 235174, cl. H 02 M 1/08, H 02 R 13/16, 1969. 3. V. Barsky, “Separate Control of Reg. Regulated Thyristor Converters. Energie, M., 1973, p. 104, fig. 3-4a and 3-4 (5 (prototype).