SU961096A1 - Digital phase-shifting apparatus - Google Patents

Description

(5) DIGITAL PHASE SURROUND DEVICE

one

The invention relates to digital devices for controlling the phase of control pulses and can be used in systems of pulsed-phase control of thyristor converters with natural commutation.

A digital phase-shifting device is known, which contains a null-organ, a clock pulse generator, a block for recording a code for phase shift 1.

The drawback of the device lies in the lack of reliability due to the delay of the control angle code relative to the control angle.

The closest in technical essence to the present invention is a phase-shifting device comprising a clock generator, a clock counter, a control angle code register, a code comparison unit, a current code counter

angle values and null indicators, the clock generator output being connected to the clock counter 2 input.

A disadvantage of the known device is that the recording of the code of the angle of control occurs twice in the period, which leads to a distortion of the adjustment characteristic for

to account for the delay of the recorded angle value relative to the control voltage at the time of formation of pulses, which reduces reliability because it can lead to violation

15 sequence turn on thyristors. For example, if immediately after the recording of the angle code a control voltage is thrown, the channel in which the angle has started to be counted can throw out this surge with a delay of l8o.

The aim of the invention is to increase reliability by eliminating the 3. distortion of the adjustment characteristic of the thyristor converter. The goal is achieved by the fact that a digital phase-shifting device for controlling a t-phase thyristor converter is equipped with an analog-to-digital converter of a control voltage into a control angle code, one-oscillators, and IS-E elements, and the outputs of the K-lowth counters of the clock pulses are connected to inputs of the analog-digital converter, its outputs are connected to the inputs of the register, whose outputs are connected to the V-inputs of the code comparison block, the second inputs of the comparison block are connected to the outputs of the The code counter, the counting inputs of this., the counter are connected to the K + 1 output of the clock counter, the inputs. The reset of the code counter is connected to the outputs of the AND-NOT elements whose inputs are connected to the outputs of the single-oscillators. The INPUTS of the single-oscillators are connected to the direct and inverse outputs nullindicatoro, as well as to the first inputs of the NAND elements, the second inputs of which are connected to the outputs of the code comparison block. . The drawing shows the block diagram of the device for one pair of antiphase pulses. The device contains 1 clock pulse generator, 2 clock pulse counter, analog-to-digital converter (ADC) 3 control voltage to control angle code, control angle code register control comparison block 5, counter 6 codes of the current angle value, AND-7 element , one-shot 8 and 9, a zero-indicator 10 and elements of NAND and 12. The input signal is indicated by the position 13, the enable signal is recorded. si-lit Generator 1 output is connected to the input of counter 2, outputs of the K-low bits of counter 2 are connected to the inputs of the A / D converter 3, its outputs are connected to the inputs of the register, outputs of which

that are attached to

the first

the input of block 5, the second inputs of block 5 are connected to the outputs of counter 6. The counting inputs of counter 6 are connected to output K + 1 of counter 2, the inputs Reset of counter 6 are connected to the outputs of elements 7, the inputs

Claims (2)

Invention Formula A digital phase shifter for controlling a T-phase thyristor converter containing a clock generator. 64. which are connected to the outputs of the single vibrators 8 and 9. The inputs of the single vibrators 8 and 9 are connected to the outputs of the null indicators 10, as well as to the first inputs of the AND-NE elements 11 and 12, the second inputs of which are connected to the outputs of the block 5. The device operates as follows. The output signals of the K-low bits of counter 2 are fed to the input of the ADC, to which the control signal 13 also arrives. At the moment of obtaining the code value of the control angle by the write resolution signal, the code is written to register k. The counting inputs of counter 6 of the codes of the current angle receive a signal K + 1 of counter 2. In this case, a comparison is made to the current same tact. values of the code of the angle of control, which ensures a constant tracking of the angle of control for a change in the control voltage. The counters 6 are reset to the zero state via the AND-NES element and the single-oscillators B and 9, by the switching fronts of the null-indicators 10 at any change in the sign of the switching voltage. At the moment when the control angle code becomes larger than the current angle code, the code comparison unit 5 generates a signal arriving at the inputs of the AND-NE elements 11 and 12. Depending on the polarity of the switching voltage, this signal, which is a control pulse, arrives at thyristor control electrode, the switching voltage of which is positive. Due to the fact that the device continuously monitors the code for the phase shift angle of the control voltage, the distortion of the control characteristic is eliminated. This eliminates the possibility of violation of the sequence of switching on the thyristors and, therefore, increases the reliability of operation. The counter of clock pulses, the control angle code register, the code comparison block, the counter of codes of the current angle value and null indicators, the clock generator output connected to the counter input clock pulses, characterized in that, in order to increase reliability by eliminating the distortion of the adjusting characteristics of the thyristor converter, it is equipped with an analog-to-digital control converter of the control voltage in the control angle code of one-vibration, elements, and-NOT, with the output of 1 K-minor bits of the clock counter pulses connected to the inputs of the analog-digital converter, its outputs are connected to the inputs of the register, the outputs of which are connected to / from the inputs of block 6 comparison codes, the second inputs of the comparison block are connected to the outputs of the code counter, the counting inputs of this counter are connected to the output of the K + 1 bit of the counter of clock pulses, the inputs of the Reset code counter are connected to the outputs of the NAND elements whose inputs s are connected to the outputs of the monostable multivibrators, connected to the inputs of monostable multivibrators direct and inverted outputs of the zero indicators and tayuke to first inputs of AND-NO element, whose second inputs are connected to outputs of block eravneni .kodov. Sources of information taken into account in the examination of the USSR Copyright Certificate №629621, cl. H 02 R 13/16, 1977. 2. USSR author's certificate and 605305 ,. cl. H 02 R 13/2, 1976;