SU1092693A1 - Device for controlling commutator of three-phase voltage source for electrochemical units - Google Patents

Abstract

DEVICE TO CONTROL SWITCH PHASE POWER VOLTAGE FOR ELECTROCHEMICAL DEVICES comprising a phase synchronizer, the outputs of which are connected in each phase through the respective differentiating element with a first adder input and via respective conditioners rectangular pulses - to the first inputs of two-input AND gates, vtorae inputs of two-input AND gates connected with the output of the block is a match. niv, and exits through the memory block. P power amplifiers, the outputs of which are intended to be connected to the switch inputs, one of the inputs of the coincidence unit is connected to the current setter, and the other input through the delay unit and the pulse width former, the output of the first adder, and each shaper of rectangular pulses. consists of a three-input element AND, two elements AND-NOT and an inverter, the first inputs of the three-input element AND and two elements AND-NOT are connected to the corresponding output of the synchronizer with the other outputs of which are connected the second inputs of the NAND elements are the second and the third inputs of the three-input AND element connected to the outputs of the NAND elements, the third input of one NAND element is connected to the input of the inverter, and the third input of the other NAND element is connected to the output of the inverter, the input of which is connected to The output of the delay unit is different from the fact that, in order to expand it (L Rheni technological capabilities of the voltage source, it is equipped with a slave adder, trigger, generator of trigger pulses, three-input. elements And, moreover, the outputs of the memory unit through the second adder are connected to the counting input of the trigger, the reset input of which is soy; The output of the pulse shaper is one of the pulses, and the outputs are connected to the first inputs of the three-input elements And, the second inputs of the three-input element And are connected to the output of the generator of trigger pulses, and the third inputs - with the outputs of the corresponding square drivers and poles, and the outputs of the three-input elements And are connected to the inputs of the amplifier-shapers.

Description

The invention relates to an electrical device, can be used for the technological voltage sources of electrochemical plants. i A device for controlling a pulsed voltage source is known, which contains a sync pulse allocator, a pulse width former, a pause duration former, memory elements, logic cells and amplifiers (1. The device has a small output voltage control range, as a result of which their time shift of the sequence of control pulses by the magnitude of the larger period of their following. The closest to the invention according to its technical essence is a sequence A three-phase voltage source control switch for electrochemical plants that contains a three-phase synchronizer included in phase-shaped zero-organs, the outputs of which are connected via phase-connected differentiating elements to the inputs of the summing unit and simultaneously through the sync pulses, the number of which corresponds to the number of phases , to the same inputs of the phase elements And, the outputs of which are connected through the serially connected memory block and phase amplifiers form The connectors are connected to the inputs of the controlled switch, and the other inputs of all three-phase elements are connected to the output of the coincidence element, one input of which is connected to the terminal for switching on the technological current source, and the second input through the delay unit and the pulse width former . Moreover, each sync pulse conversion unit is made on an AND element, two NAND elements and an inverter, the first inputs of all three elements are connected to one of the phases, the second inputs of the AND AND elements are connected respectively to the input and output of the inverter, whose input is simultaneously connected to the output the delay lines, the third inputs of the NAND elements are connected to two other phases, and the outputs of the NAND elements are connected respectively to the second and third inputs of the AND element, the output of which is connected to the input of the corresponding phase element II. For an accurate high-performance electrochemical shaping process, it is necessary to vary within wide limits such process voltage parameters as the amplitude and frequency of the pulse. Moreover, at the initial stage of processing, the technological voltage should be maximal. Since the load of the power source at this stage is insignificant, the power source operates in a mode close to the idle mode, for which there is a critical angle of control o. : p equal to 4.0-50 °, so that when the regulation is not possible, since insignificant adjustment angles are required to obtain the maximum process voltage, regulation in this voltage area in a known device presents certain difficulties. Avoiding them allows an increase in the duration of the control pulses to a value of at least 3 ms. Moreover, in order to reduce the control power, there is no need to constantly have such a duration of control pulses, and it would be desirable to reduce it as the load of the power supply increases and the process voltage decreases, which is necessary for the final stage of processing. Obtaining such a magnitude of control pulses and adapting it to the process in a known device is not possible. The frequency of the control pulses of the controlled switch and, consequently, of the technological voltage pulses in the known device is constant and equal to 150 Hz. It can be changed only with the help of a complex re-switching in the memory block, which reduces the reliability and stability of the power supply. Thus, due to the lack of adjustment of the amplitude of the technological voltage pulses in the region of small cL in idle mode and the difficulty of changing their frequency, the known device has. Malug 4 and technological capabilities, which limits its scope. The purpose of the invention is to expand the technological capabilities of the voltage source. This goal is achieved by the fact that the device for controlling a three-phase source switch is for electrochemical installations, containing a three-phase synchronizer, the outputs of which are connected in each phase through corresponding differentiating elements to the inputs of the primary adder and through the corresponding shapers of square: pulses to the first inputs the two-input elements And, the second inputs of the two-input elements And are connected to the output of the matching unit, and the outputs through the memory unit - to the amplifiers Atel E, kotopttx outputs. they are intended to be connected to the switch inputs, one of the matches block inputs is connected to the current setpoint device, and the other input is connected to the output of the first adder through the delayer and the pulse width former, and the square pulse shaper consists of a three-input AND element, two AND-NOT elements and an inverter, the first inputs of the three-input element AND and two elements NAND are connected by d corresponding input of the synchronizer with other outputs of which the second inputs of elements NAND are connected, the second and third inputs of the input element AND is connected to the outputs of the NAND elements, the third input of one element IS-NOT is connected to the input of the inverter, and the third input of the other element IS-NOT connected to the output of the inverter, the input of which is connected to the output of the delay unit, is equipped with a second adder, a trigger, three-input elements And and a trigger pulse generator, the outputs of the memory unit through the second adder are connected to the counting trigger input, the reset input of which is connected to the output of the pulse width generator, and the outputs are connected to the first odes trehvhodovyh element and the second inputs of the AND trehvhodovogo connected to the output trigger pulse generator, and the third input - to the outputs of respective pulse formers rectangular and trehvhodovyh outputs of AND gates are connected to inputs shaping amplifiers.

FIG. 1 is a schematic diagram of the device; in fig. 2 time diagrams for his work.

The device for controlling the switch of the three-phase voltage source contains a three-phase synchronizer 1, a semiconductor switch 2 whose outputs are connected to a three-phase valve transformer 3. Three outputs of the synchronizer 1 are connected through differentiating elements 4-6 and the first adder 7 to the pulse width former 8, which also and synchronizer 1 is connected to three square pulse drivers 9-11. In each of these blocks, one of the phases of the synchronizer 1 is connected to the input of the three-input element I 12 and simultaneously to the first inputs of the three-input elements AND-NOT 13 and 14. The remaining two inputs of one of the elements AND-NOT 13 are connected to the leading phase of the synchronizer 1 and the output of the duration ramp. pulses 8, and the remaining inputs of the other element AND-NOT 14 - lagging phase and through the inverter 15 - output of the driver long t ;: pulses 8. The outputs of the elements AND-HE 13 and 14 are connected to the remaining two inputs of the element 12. The outputs of the blocks 9 -11 connected to n The first inputs are two-input elements And 16-18.

To the second inputs of the elements And 16-18 is connected through the delay unit 19 and the element coincidence 20 output

0 pulse width generator 8. The outputs of the AND elements 16-18 through the memory block 21 and through the second adder 22 are connected to the counting input of the trigger 23, the reset input of which is connected to the output of the pulse width former 8. The output of the trigger 23 is connected to one of the three inputs elements 24-26 and each of their other inputs are connected to a generator of triggering pulses 27 and the corresponding output of a rectangular pulse generator 8, 10, and 11, and the outputs of elements 24-26 are connected via amplifiers 28-30 to control inputs semiconductor commutator {torus 2.

FIG. 2 shows rectangular sync pulses with a duration of IbO el.grasht, at the output of sync0

and

and

torus 1 - and

impulses

-J8

1C

-1A

the voltage at the output of the valve transformer 3 - U2, the sequence of control. and fflylyv U-, output pulses of duration with

5 pulse shapers Ug, rectangular clock pulses at the output of rectal pulse shapers 9-11 duration

120 PLN hail. - and

and.

and

- YOU9

ten

travel needle pulses of delay unit 19 and

command to turn on the technology19

chesky current and

weekend imwtt

trigger pulses 23 - and., control pulses and 24 f 26 2b

The device works as follows.

5 way.

When a three-phase voltage is applied to the outputs of the synchronizer 1, right-angle clock pulses U, d, U, g, U -k are formed;

0

duration 180 e. hail. Passing through the differentiating chains 4-6 and the first adder 7, the sync pulses are transformed into a sequence of short duration UT control pulses with a shift 120 eh grades. and with the following period T, which is converted by the pulse shaper 8 into pulses Ug of duration t

0

Square shapers named jibcoB 9-11 reduce the duration of the clock pulses U.c, U, | g, and., C to a value of 120 eh grades. by shortening them from CTOpciHu of the front and rear edges depending on the value of T, which determines the phase of the new sync pulses Uj,, and. These sync pulses are resolution pulses for AND elements 16-18. The pulses Ug also arrive at the delay block 19, where along their falling edge they are formed and shifted by f 2 relative to and the pulses of short duration U e are delivered to the coincidence element QO. The value of t: determines the angle of the thyristors of the semiconductor switch 2. When the command to turn on the technological current U Hg control is issued, the pulses U arrive at. the inputs of the elements 16-18 and, if available, the resolution pulses Od and pass to the memory block 21. From the output of the memory block 21, the control pulses through the second adder 22 arrive at the counting input of the trigger 23g to the reset input of which pulses Ug . Moreover, the resetting of the three-hera 23 is carried out on the trailing edge of the pulses Ug. Thus, the trigger 23 generates a sequence of pulses Ux, duration H- T (1). Assuming that the match (1) takes the form 4. -T — If there are enabling synchronizing pulses Ug, U.JO, the pulses Ujj modulated by the frequency of the trigger pulse generator 27 pass through the elements 24-26 on the amplifiers driver 28-30 and then to the corresponding inputs of semiconductor switch 2. This ensures the appearance of voltage pulses V of a certain duration at the output of a valve transformer with a rectifier unit 3. Moreover, the duration of control pulses 24 2S 2k varies depending on the control angle d-, you ekaet from equation (2). In order to form technological voltage pulses with a following frequency of 75 Hz in the proposed device, it is enough to swap the phase ends of any two elements And 16-18 at the input of the memory block. In this case, in a memory block organized, for example, by the principle of a shift register, an exception occurs after one impulse I. „, which corresponds to the frequency of their succession equal to 75 Hz. Thus, an increase in the duration of the control pulses and its adaptation to the magnitude of the thyristor control angle allows the power source to operate in the area of maximum process voltages during idle mode. This and the possibility of changing the frequency of the technological pulses allows us to expand the technological capabilities and the field of application of power sources for dimensional electrochemical processing. Thus, the proposed control device has great technological capabilities as compared with the prototype, which results in an increase in the maximum voltage of the power source. This reduces processing time by 50%. The basic control system makes it possible to obtain control pulse durations of 0.15-0.20 ms, which is not enough to ensure the operation of the power source in the region of small angles of regulation of the thyristors of the semiconductor switch at near idle modes. This significantly affects the magnitude of the maximum voltage of the power source and, consequently, the processing performance with its use. The use of this device as compared to the base voltage allows to significantly increase the maximum voltage of the power source, due to the extension of the duration of the control pulses to 6/7 ms at the thyristor control angle close to Oeh.grad., Which, in turn, leads to a reduction in processing time.

FI.2

Claims (1)

DEVICE FOR CONTROL OF A THREE-PHASE VOLTAGE SOURCE FOR ELECTROCHEMICAL INSTALLATIONS CONTROLLER, containing a three-phase synchronizer, the outputs of which are connected in each phase through the corresponding differentiating elements with the inputs of the first adder and through the corresponding formers of rectangular pulses - with the first inputs and two inputs of two inputs block output coincides. niya, and the outputs through the memory block. - r amplifiers-shapers, the outputs of which are intended to be connected to the inputs of the switch, one of the inputs of the coincidence unit is connected to the current master, and the other input, through the delay unit and the pulse shaper, is connected to the output of the first adder, and each rectangular pulse shaper consists of a three-input the AND element, two AND-NOT elements and an inverter, the first inputs of the three-input AND element and the two AND-NOT elements are connected to the corresponding output of the synchronizer with the other outputs of which the second e inputs of AND-NOT elements the second and third inputs of the three-input AND element are connected to the outputs of AND-NOT elements, the third input of one AND-NOT element is connected to the inverter input, and the third input of the other AND-NOT element is connected to the inverter output, the input of which is connected to the output of the delay unit, characterized in that, in order to expand the technological capabilities of the voltage source, it is equipped with a second adder, a trigger, a trigger pulse generator, three-input elements And, and the outputs of the memory unit through a second adder are connected to about the counting input of the trigger, the reset input of which is: dined with the output of the pulse shaper, and the outputs are connected to the first inputs of the three-input elements And, the second inputs of the three-input element And are connected to the output of the trigger pulse generator, and the third inputs are connected to the outputs • forming shafts of rectangular pulses, and the outputs of the three-input elements And are connected to the inputs of the amplifiers-shapers. SU., "1092693>