SU845258A1 - Digital device for control of thyristirized unit - Google Patents

Description

the converter and does not provide control of the thyristor unit according to an algorithm different from the principles of pulse-phase control.

The aim of the invention is to expand the functionality of the control device.

This is achieved by the fact that the digital device for controlling the thyristor unit is equipped with an additional decoder, six additional AND elements, an NOT element, two OR elements, and the inputs of the first decoder are connected to the logical outputs of the second counter and to the output of the first counter, the additional decoder BXOjObi of the additional decoder are connected to logical outputs the outputs of the third counter, additional element And the inputs are connected to the three first outputs of the first decoder, the second inputs of the additional elements And connected to the output of the NOT the input of the additional decoder connected to the last output, the inputs of the first and second elements of the switchgear are connected to all outputs of the first and second decoders respectively, the outputs of the first and second elements OR are connected respectively to the fault inputs of the first and second counters, and the output of the pulse generator is connected to the first the counter through the element And, the second input of which is connected to the output of the control unit.

 FIG. 1 shows the power circuit of a constant electric drive with a thyristor unit; in fig. 2 digital device for controlling the thyristor unit.

The power circuit contains motors 1 and 2 with successive windings 3 and 4 and excitations, in series with which start-up rheostats 5 and 6 connected via a linear contactor 7 and the positive pole of the power source. The starting rheostat 6 is divided into three parts of equal resistance, connected with the help of contactors 8, 9 and 10. The starting rheostat 5, the value of which is equal to one of the parts of the starting rectifier 6, is also divided into equal parts that are shunted by thyristors 11- 16 thyristor block and contactor 17. Parshgpelno

The windings 3 and 4 of the excitation and the rheostat 5 through the contactor 18 are connected to the rheostat 19 of the weakening field and the inductive shunt 20. The rheostat 19 of the weakening field is divided into three parts by connecting the thyristors 21, 22 and the contactor 23. In addition, from the ground the power circuit is connected by a linear contactor 24

The digital device for controlling the thyristor unit (see Fig. 2) contains a pulse generator 25 connected to one input of the AND element 26, to the other input of which the output of the control unit 27 is connected. 1 The input element I 26 is connected to the counting input of the first counter 28, the output of which is connected to the input of the first decoder 29 and to the counting input of the second counter 30, whose logical outputs, which are the forward and inverse outputs of the counter triggers, are connected to the logic inputs of the first decoder 29 The overflow output 31 of the second counter 30 is connected to the counting input of the third counter 32, the logical outputs of which are connected to the inputs of the additional decoder 33. The outputs 34-40 of the first decoder according to the number of start-up cycles The rheostat 5 is connected to the inputs of the first IZH element 41 by the outputs of the first counter 28 connected to the reset input 42. The counter 30 has a reset input 43. The first three outputs 34, 35 and 36 of the decoder 29 are connected to the same inputs of the And 44, 45 and 46 elements first groups 47 and to the same inputs of elements And 48, 49 and 50 of the second group 51, other inputs of elements And groups 47, 51 are connected to the output of the element HE 52, whose input is connected to the last output 53, additional decoder 33, also having outputs 54, 55 and 56. The outputs 53-56 of the additional decoder 33 are connected to the second CB OR element 57, whose output is connected to the reset input 53 of the second counter 30. The outputs of decoders 29 and 33 and group 47 elements and 5 are connected to the corresponding elements of the power circuit (see. FIG. 1), which are indicated in brackets in FIG. 2

The device works in the following way.

Initially, according to a Komavda line from the control unit 27, the line contactors 7 and 24 are turned on (see Fig. 1).

When one of the operating modes of the power circuit is installed, the control unit 27 sends a signal to one input of an element 26, to the other input of which impulses are received from the generator 25 at a frequency of its operation. These pulses lead to a change in the state of the triggers of the counter 28, after filling which from its output simultaneously a signal is sent to the input of the decoder 29 and to the counting input of the second counter 30. The counter 30 changes its state. In accordance with the establishment of the first state of the counter 30, its binary outputs receive a binary code to the logical inputs of the first decoder 29, which leads to the appearance of a signal at the first output 34 of the decoder 29. This signal through the And 44 element of the first group 47 elements And, since at this stage of regulation the signal from the output of the element NOT 52 is sent to the second inputs of elements AND of this group, the thyristor 11 enters (see Fig. 1) At the same time, the signal from the output 34 of the decoder 29 through the element OR 42 steps to the fault input 43 first counts ka 28, returning it to the zero state. At the same time, from its output, the signal to the input of the decoder 29 stops feeding, which leads to a loss of the signal at the output 34 of the decoder, despite the fact that the counter 30 is in the first state. The latter leads to an increase in the noise immunity of the system and to a decrease in power consumption .

After the counter 28 has returned to the zero state, its filling again begins with pulses coming from the generator of 25 pulses. After filling the counter 28, a signal appears at its output, which is fed to the depigraphor 29 and to the counting input of the second counter 30, which assumes the second state. In accordance with the code received by the logical outputs. The counter 30 appears at the second output 35 of the decoder 29 which, through the element 45, enters the thyristor 12 (see Fig. 1). Receipt of the same signal to the element OR 42 and further to the fault input 43 of the counter 28 will again lead to the return of the counter 28 to the zero state.

Each subsequent filling of the first counter 28 will lead to the next change in the state of the second counter 30 and, accordingly, to a sequential detection of the signals at the outputs 36-39, which arrive at the thyristors 13-16.

The arrival of the seventh pulse at the input of the second counter 30 will result in a signal at the output 40 of the decoder 28 which will turn on the contactor 17. On the eighth state of the counter 30, output 31 sends an overflow signal to the third account, chick 32, which takes its first state in which at the output 56 of the additional decoder 33 a signal appears that goes to the contactor 8, while opening the contactor 17 simultaneously.

At the same time, the output 56 through the element OR 57 sends a signal to the fault input 43 of the second counter 30, returning it to its original state.

The subsequent filling of the first counter 28 will cause the overflow signal to be sent to the second counter 30, which at each successive filling of it will allow the signals at the output 34-40 of the decoder 29 to appear successively with the contactor 8 closed. The arrival of the eighth signal from the output of the first counter 28 to the input of the second counter 30 leads to a change in its state, which causes the overflow synal to be supplied to the third counter 32, which in this case will occupy the second state. In this state of counter 32, a signal appears at the second output 55 of additional decoder 33, which enters ira contactor 9, and the flow of this signal to the fault input 43 of counter 30 through element 1-ШИ 57 returns it to its original state, while the contactor is turned off 17.

Subsequent cycles of filling the second counter 30 will again result in a sequential occurrence

signals at outputs 34-40 of the decoder 29. At the next overflow of the hatch 30, a signal comes in again and the counting input of the third counter 32, which then takes the next j third state, in which o is the signal at the output 54 of the additional decoder 33, which arrives at the contactor 10, while simultaneously resetting the second counter 30 to the initial state and turning off the contactor 17. At the next filling cycle of the second counter 30, the signals at the outputs 34-40 of the decoder 29 and c will appear sequentially. Responsibility is a set of positions 26-32. When counter 30 overflows, a signal is output at output 31 to a third counter, which then takes its fourth state, in which the output 53 of additional decoder 33 appears. This signal goes to contactor 18 , including the circuit 25 for regulating the attenuation of the zero (see Fig. 1). At the same time, this signal is fed to the input of the HE element 52, from the output of which the signal will disappear, excluding the AND element of the first group 47 from operation. 21 and 22 and the contactor 35 23 of the weakening circuit of the windings of the 3 and 4 excitations.

So, with the next fillings of the first counter 28, which will change the state of the second counter 49 30, the signals will appear: at output 34 of the decoder 29, which through element 48 comes to thyristor 21 at output 35, which through element 49 will go to thyristor 5, 22, and, finally, from output 36 will go to contactor 23, thereby setting the maximum degree of weakening of the field.

Thus, a digital 50 device for controlling in accordance with the description is provided

the ability to provide digital control of the thyristor unit, which regulates the magnitude of the starting rheostat and the magnitude of the degree of attenuation of the magnetic flux of the traction motors.

Claims (2)

1. USSR author's certificate number 366540, cl. H 02 R 13/16, 1969. 2. For Japan Japan 51-32496, cl. H 02 M 1/08, 1976. ss 4Hi v. "3 and V -and -N hell t t -J4