RU1786617C - Device for control over thyristor interrupter for layer-period electroslag welding - Google Patents

Description

The features distinguishing the claimed solution from the prototype are not revealed in other technical solutions when studying this and related technical fields and, therefore, provide the declared solutions with the criterion of Substantial differences.

In FIG. 1 is a block diagram of a control device; in FIG. 2 timing charts.

The thyristor circuit breaker control device for layered-period electrode electroslag welding contains a voltage phase sensor 1 that generates rectangular pulses, the leading edges of which correspond to positive and negative transitions of the mains voltage through zero, and short pulses at times corresponding to the phase of the mains voltage 90 and 270 electric grad., a sawtooth voltage generator 2 of a step shape, a control trigger 3, a voltage-shaping unit 4 of a triangular-step shape, a zero-organ 5, a there are 6 pulses along the front of the input signal, three ZI-NOT elements 7, 8, and 9 and a pulse amplifier 10.

In the presented voltage diagrams (Fig. 2), the voltages on the circuit elements have the index of this element, so 1Io is the voltage at the output of the element 10.

From the fourth output of the voltage phase 1 sensor, synchronization pulses are fed to the input of a step-shaped sawtooth voltage generator 2, synchronizing it with the frequency of the supply network. From the third output of the step-shaped sawtooth voltage generator 2, short pulses, the trailing edges of which correspond to the moment of formation of the step-shaped sawtooth voltage, are input to the trigger trigger 3. From the first and second outputs of the generator 2, a step-increasing and step-decreasing voltage is supplied to the information inputs of a voltage-forming unit 4 of a triangular-step form, and to the control inputs, signals from the direct and inverse outputs of the control trigger 3.

The time interval forming unit 4 sets a control period, and at a predetermined period, a triangular-step voltage is generated, which is applied to one of the two inputs of the zero-organ 5, to the other input of which the reference voltage is supplied. From the output of the null-organ 5, the signal enters the input of the 6 pulse shaper along the front of the input signal and the first input of the element

ZI-NOT 9. The signal from the output of the 6 pulse shaper is fed to one of the two combined inputs of the ZI-NOT 7 and 8 elements, the other combined input of which 5 receives a signal from the first output of the voltage phase 1 sensor, from the second and third outputs whose rectangular pulses, the leading edges of which correspond to. yut positive and negative

0 transitions of the mains voltage through zero, respectively, are supplied to the third inputs of the elements ZI-NOT 7 and 8, the output of which is connected respectively to the second and third inputs of the element ZI-NOT 9, the output of which

5 controls the operation of the pulse amplifier 10. From the output of the latter, control pulses are fed to the input of the thyristor chopper.

The control device operates as follows.

Suppose that at time ti (see Fig. 2), the zero-element 5 is triggered. 5. On the front of the signal from the output of the zero-organ 5, the shaper 6 pulses along the front of the input Signal 5 form a pulse with a duration of 15 ms 15 (time interval ti-t4), which arrives at the combined first inputs of elements ZI-NOT 7 and 8. The combined, second inputs and third inputs of the latter receive impulses from the first, second and third outputs of the voltage phase 1 sensor, respectively. At the same time, a high logic level is set simultaneously at all inputs of the ZI-NOT 8.

At the output of the ZI-NOT 8 element, a low logic level is set. At time 2, the ZI-NOT 8 element is closed by a logic zero level coming from the first and third outputs of the phase 1 sensor

0 voltage, and at its output a logic unit level is set. At the same time, the signal from the output of the element ZI-NOT 9 prohibits the operation of the pulse amplifier 10. At the time ts, a high logical level

5 is installed simultaneously at all inputs of the ZI-NOT 7 logic element, coming from the first and second outputs of the voltage phase sensor 1 and from the output of the pulse shaper 6. At the same time, at the output of the ZI-NOT 7 element, a logic zero level appears, which arrives at the second input of the ZI-NOT 9 element, from the output of which a high logical level allows the short-term operation of pulse bodies 10 with a phase angle of 90 el. At time IA, at the same time, all inputs of the ZI-NOT 7 element are set to a low logic level, and a logic level appears at its output

units. In this case, the element ZI-NOT 9 prohibits the operation of the pulse amplifier 10,

At time t5, null-organ 5 returns to its original state, i.e. at its output, a low logic level is set, which is supplied to the first input of the ZI-NOT 9 element, and the second and third inputs of which are supplied with the level of a logical unit. In this case, the signal from the output of the element ZI-NOT 9 allows the operation of the pulse amplifier 10 with a phase angle of 270 el.

At time ta, a null-organ 5 is triggered. On the signal front from the output of the last, the pulse shaper b generates another pulse with a duration of 15 ms. At the same time, a high logic level is established at all three inputs of the logic element ZI-NOT 7. At the output of the element ZI-NOT 7, a low logic level is established. At the moment the voltage of the network passes through zero (moment t), the ZI-NOT 7 element is closed by a low logic level coming from the first and second outputs of the voltage phase sensor 1, and a high logic level is established at its output. In this case, the signal from the output of the ZI-NOT 9 element prohibits the operation of the pulse amplifier 10. At the time ta, at the same time, all inputs of the -ZI-NOT 8 element are set to a high logic level coming from the first and third outputs of the phase T sensor, for example. nor from the output of the shaper 6 pulses. At the same time, at the output of the ZI-NOT 8 element, a logic zero level appears, which goes to the third input of the ZI-NOT 9 element, from the output of which a high logical level allows short-term operation of the pulse amplifier 10 with a phase angle of 270 el. At time tg, a logic zero level is set at all inputs of element 8, and a high logic level appears at its output. In this case, element ZI-NOT 9 prohibits the operation of pulse amplifier 10.

The next thyristor circuit breaker cycle begins with a phase angle of 90 degrees, (time xy).

The proposed device does not require the introduction of a phasing unit to demagnetize the transformer. This simplifies the setup of the thyristor circuit breaker control device.

Claims (1)

The claims A device for controlling a thyristor interrupter for period-wise-period-electric-varnish welding, comprising a voltage phase sensor with a first output short pulses at times corresponding to the phase of the mains voltage of 90 and 270 electric degrees, the second and third outputs of rectangular pulses, front the edges of which correspond to positive and negative transitions of the mains voltage through zero and the fourth output of the synchronization of the sawtooth voltage generator of a stepped form, a zero-organ, one of the inputs of which is intended for connecting a reference signal, a pulse shaper along the front of the input signal, a pulse amplifier, which, in order to increase reliability by simplifying the circuit, a control trigger, three ZI-NOT elements and a triangular-shaped voltage-generating unit are introduced to it, and a sawtooth-shaped voltage-generating generator is additionally equipped with an output of a decreasing-voltage and an output of short pulses, the leading edges of which correspond to comfort to the moment of formation of a sawtooth voltage in a step-like form, the first and second information inputs of a voltage-forming block of a triangular-step shape being connected respectively to the output of a stepwise increasing and the output of the step-decreasing voltage of the sawtooth voltage generator of the stepped form, and the first and second control inputs are connected to the corresponding outputs of the control trigger, the input the control of which is connected to the output of short pulses of a sawtooth voltage generator of a stepped form, while the first combined inputs of the first and second elements ZI-NOT connected to the output of the pulse shaper along the front of the input signal, the second combined inputs of the first and second elements are ZI-NOT connected to the first output of the short pulses of the voltage phase sensor. and the third inputs of the first and second ZI-NOT elements are connected respectively to the second and third inputs of the square, n and pulses of the phase sensor. voltage, while the first input of the third the ZI-NOT element is connected to the input of the pulse generator along the front of the input signal and the output of the zero-organ, the second input of which is connected to the output of the voltage-forming block of the triangular step 5 shape, the second and third inputs of the third ZI-NOT element are connected to the outputs of the first and the second element ZI-NOT, the output of the third element ZI-NOT connected to the input of the pulse amplifier. None Of Uu DM and, 1LGSH LLL LLL LG-YAG / 1 // 1L I I  " I I