SU877778A1 - Thyristor control device - Google Patents

Description

The invention relates to electrical engineering, namely, to a powerful source of power for DC power consumers and, in particular, to such sources that are required to precisely set the output voltage. A thyristor control device based on integrated circuits is known which uses the frequency-impulse control principle. The device contains a master oscillator, a oscillator, a pulse shaper, output amplifiers, thyristors, 13 The disadvantage of such a device is that it does not provide linear adjustment of the output to the yarn, i.e. proportional relationship between the input of the regulator and the value of the output voltage. The closest to the proposed technical entity is a thyristor control device, containing a master oscillator, a synchronizer connected to the network, an AND gate, a counter, a comparator unit, a digital control code driver, a pulse driver, an output amplifier, and thyristors. the outputs of the synchronizer and the master oscillator are connected to the inputs of the element I, the output of which is connected to the input of the counter, the outputs of the counter and the driver of the digital control code are connected to the inputs of the comparator, the output of which is connected to the input of the driver of pulses, and the output of the driver of the pulse generator is connected to the input of the amplifier, the output of which is connected to the control electrode thyristors. A disadvantage of this device is that it does not provide a linear relationship between the input signal (digital control code generation unit code} and output rectified voltage. The purpose of the invention is to provide a linear relationship between the input control signal and the output rectified voltage. Delivered The goal is achieved in that the thyristor control device is equipped with a functional converter and a voltage-frequency converter, with the input of the functional converter is connected to the mains, the output is connected to a voltage-frequency converter, the output of which is connected to the counter input of the counter, the installed input of which is from the synchronizer output 5. Figure 5 shows the functional diagram of the device shown in Figure 2 is a timing diagram, illustrating the state of individual device nodes.

The device consists (Fig. 1 of a voltage-frequency converter 1 connected in series, counter 2, comparison unit 3, to the input of which a digital control code generation unit 4 is connected, a pulse shaper 5, a coincidence unit 6, an amplifier unit 7 (for positive and negative half-periods,), thyristors 8, functional converter 9 connected to voltage-frequency converter 1 and network, synchronizer 10 connected to counter 2, coincidence unit 6 and network.

The device works as follows (device operation is presented for Single Phase).

A sinusoidal mains voltage (Fig. 2, a) is fed to the input of a converter 9, from the output of which is fed to the control input of a voltage-frequency converter 1 Signals of the back ground form (Fig. 2) {HL As a result voltage-to-frequency converter 1 generates pulses at intervals / proportional to coscyt, and the duration of each packet is approximately equal to the loop voltage of the network (Fig.). The number of pulses in each bundle must correspond to the number of stages of adjustment. In counter 2, after each zero signal of synchronizer 10, as the mains voltage passes through zero (Fig. 2.6), the counting of pulses begins, the value of which is continuously digital block 3 comparison. At the same time, the other input is supplied from the digital control code generation unit 4, which is a voltage-to-voltage converter, a predetermined value, which is determined by the input control action Uypp and determines the unlocking angle of the thyristor 8. At the time when Both digital values become equal, single signals (twice per period, Fig. 2, yic) appear at the output of the comparator unit 3, which, when fed to the imaging unit 5, are converted into pulses of the duration necessary to open the thyristors (Fig. 2). From the output of the pulse shaper 5, signals are fed to a block 6 of coincidence, and the other inputs from the synchronizer 10 are fed to clock pulses.

foot and, respectively, negative half-period (Fig. 2, t, d).

Moreover, their duration corresponds to the time of one half-wave. Thus, the separation of the control signals of the positive and negative half-periods into separate independent channels occurs (Fig. 2, U., Lc). After block 7 of the amplifiers, power amplified pulses fall on the control electrodes of the respective tristors.

The linear relationship between the control signal and the rectified output voltage is obtained due to the uneven intervals between the discrete steps that determine the opening angles of the thyristors for each half-period of the mains voltage. Moreover, these intervals should be such that the areas bounded by the sinusoid of the mains voltage and the ordinates of the opening angles of the thyristors would be equal to each other, in this case the average increment of the straightening voltage for each stage of adjustment will be uniform.

The adjustment steps must be changed in accordance with the values of the cosine function.

Thus, the introduction of additional devices and connections allows to obtain a linear dependence of the rectified voltage on the unlocking angle of the thyristors.

Claims (2)

1. Authors certificate of the USSR 350124, cl. H 02 R 13/16, 1964. 2. USSR author's certificate “according to application No. 2669479, cl. H 02 R 13/16, .1977. 0