SU548848A1 - AC voltage regulator with high frequency link - Google Patents

Description

and 14-1 /, which through the filter 18 is connected to the load 19. The regulator contains sensors and 20, 21 and current 22, two-input logic circuits 23 and three-input circuits 24. Synchronized autogenerator 25 output through two-input logic circuits "And 23 connected to the control electrodes of the thyristors 2-8 of the inverter of the primary circuit of the high-frequency transformer, and the input through the delay device 26 to the master oscillator 27, to which the inputs of the phase-shifting devices 28, 29 are also connected, and their outputs and outputs of the said generators are 25, 27 h The three-input logic circuits “And 24” are connected to control electrodes of thyristors 10-17 of the transformer secondary circuit, 1. The sensor voltage 20 is connected to the mains voltage by the input, and the output to one of the two inputs of the logic circuits 23. The voltage sensors 21 and current 22 load cells are connected to the inputs of logic circuits 24. The demodulator is made by a bridge circuit on anti-parallel thyristors in each arm with natural commutation.

FIG. Figure 2 shows timing diagrams explaining the operation of the controller, where 30 is the network voltage; 31 - load current; 32 - pulses of the master oscillator 27 (Fig. 1); 33 - pulses synchronized oscillator 25; 34, 35 —control pulses of a thyristor modulator in the primary circuit of transformer 1; 36 - voltage of the secondary winding of the transformer 1; 37, 38 — pulses acting at the output of phase-shifting devices 28, 29, respectively; 39-42 — the control pulses of the thyristor demodulator in the secondary circuit of transformer 1; 43-46 are timing diagrams for switching the demodulator thyristors; 47 is the output voltage of the variable voltage regulator.

FIG. 3 shows a single cell assembled on two-input logic elements “And, where 48, 49 are two-input logic circuits“ And, performed on transistors. The windings of the synchronized oscillator 25 are connected to one of the inputs 50, the second inputs 51 are the emitter-base junctions of the transistors 7. The output terminals 52 of the transistors are combined and are connected to a control electrode, for example, a thyristor 3 (fig. 1). The control electrodes of the remaining thyristors of the primary circuit are connected to the output of a synchronized oscillator through similar cells.

FIG. 4 shows a cell assembled on three-input logic circuits And 53, 54 and made on the basis of series-connected transistors 55, 56. The numbers 57, 58, 59 denote each of the element inputs, and the output 60 is common and through a cut-off diode is connected to the control the emitting electrode of one of the thyristors of the transformer secondary circuit 1.

Indicated in FIG. 3 and 4 logic cells can also be performed on commercially available integrated circuits with subsequent switching on of the amplifiers.

We consider the operation of the regulator for the most common case of active-inductive load, when the voltage of the network 30 (Fig. 2) is ahead of the current of the narrow 31 at a certain angle and. When the power is turned on, the master oscillator 27 (Fig. 1), which can be made on the basis of both transformer-synchronizers when connecting the secondary windings of transformers in zigzag, and on the basis of autogenerators synchronized with the network

Roera begins to generate pulses 32 with a predetermined frequency (in the description an option is considered when the master oscillators and synchronized auto-generators are made on the basis of Roer auto-generators). It should be noted,

that there may be no synchronization of the wired-1, its generator with the network, for stable operation of the regulator, it is sufficient to synchronize the auto-oscillator 25 and phase-shifting devices 28, 29 with the master oscillator. Impulses

32 are fed to the input of the delay device 26 at the output of which pulses with a duration y (Fig. 2), equal to the recovery time of the thyristor locking properties, act As a delay device can

For example, a standby blocking generator triggered by frontam of 32 pulses is used. The pulses of the delay device are of duration Y and are synchronizing for the synchronized oscillator 25, the output of which produces pulses 33 delayed relative to the pulses of the master oscillator for a strictly fixed time Y - Eq pulses 33 are fed to the input of logic circuits 23, whose operation

This is illustrated by the example of the particular circuit shown in FIG. 3

The output windings of the synchronized oscillator 25 are connected to the inputs 50, and the start of the winding is connected to the emitter of the transistor of the circuit 48, and to the emitter of the transistor of the circuit 49 - the end. The inputs 51 are supplied with signals from a voltage sensor 20 (Fig. 1) with the polarity indicated in Fig. 3. With a positive half-wave of the voltage of the network 30, the polarity at the inputs 51 of the logic elements corresponds to the polarity indicated in FIG. 3 without brackets. This implies that in the presence of the supply voltage of the transistors of the circuits 48, 49, which are the pulses 33 (Fig. 2), the open state of the transistor of the circuit 48 and the closed state of the transistor of the circuit 49. However, the pulses at the output 52 will be ligp at a positive polarity, the pulses 33 acting on

the input 50. When the negative voltage voltage of the network 30 is negative (the polarity at the inputs 51 is shown in Fig. 3 in brackets), the transistor of the circuit 48 is closed and the transistor of the circuit 49 opens, so the negative half-wave of the pulses 33 will act at the output 52.

So the pulses are formed 34. The pulses 35 are formed by a similar cell, in which the beginnings of the windings connected to the inputs 50 are switched on the opposite. Said pulses 34 and 35 are applied to the control electrodes of thyristors 2, 3 and 4, 5, respectively. Tirnstorit 2, 3, 4, 5 are switched with a higher frequency according to pulses 34, 35, and in the time intervals av and a, thyristors 3 and 4 will alternately be in a conducting state, and in intervals and a ,, i - thyristors 2 and 5. The diagrams of the conducting and closed state of the thyristors in the indicated intervals correspond exactly to the duration of the pulses 34 and 35 (the open state of the thyristors 3, 5 and 2, 4, respectively) and the duration of the pauses between the impulses (the closed state of these thyristors). Such switching of thyristors connects the primary half windings of the transformer 1 to the same terminal of the network either to the beginning or the horse terminal, and when the network voltage passes through zero, it remains connected to the same terminal of the network that end or beginning of the half windings that were last connected in the previous half of the network voltage. This makes it possible to form in the secondary winding of the transformer 1 a high-frequency voltage 36 with a sinus envelope and, in addition, it can change the polarity of this voltage 36 irn by changing the polarity of the voltage of the network 30.

Each of the thyristors 7 and 8 is switched on for the entire half-period of the mains voltage and, together with the choke 9, serves to release reactive energy.

The rectification and regulation of the high-frequency voltage 36 is carried out by a demodulator on thyristors 10-17 in the secondary circuit of the transformer, which are controlled by three-input logic circuits And 24 are supplied by pulses 32 of the master oscillator, by pulses 33 of the synchronized auto-oscillator, and also out of phase by an angle adjusting Or, and f5n pulses 37, 38. These pulses are shifted by phase-shifting devices 28, 29 with adjustable angles of delay Op and advance pl, to the input of which are received pulses 32 of the master oscillator.

The principle of formation of the required pulse sequences by logical elements will be considered on the example of the operation of the logic cell shown in FIG. four.

The inputs 58 of this cell are supplied with signals, for example, from a voltage sensor, and the inputs 59 from the current sensor with the polarity indicated in FIG. 4, with the polarity indicated without parentheses corresponding to the positive half-waves of voltage and current (time interval an in Fig. 2). The inputs 57 of the logic circuits 53 and 54 are connected to the output windings of the synchronous oscillator 25 and the phase shifter 29, respectively. In the specified interval A, in the conducting state, the transistors of the circuits 53 are at

positive zero voltages 33. At the time the voltage of the network 30 passes through zero (interval ac), the polarity at the inputs 58 is reversed (in Fig. 4, this polarity is shown in parentheses), the transistor 55 of the logic circuit 53 is closed And the like transistor of the circuit 54 opens, since the transistor 56 of this circuit is energized, then negative pulses 38 will act at the output 60. When the current 31 changes its direction, the transistors 56 of both logic circuits 53, 54 are closed and at the output 60 in ts to the next changes in current direction 31. Thus, pulses 39 are formed.

For the formed pulses 40, it is necessary to turn on the windings connected to the inputs 57 back to the designation indicated by

in fig. 4, and for generating the pulses 41, 42, the windings of the phase-shifting device 28, at the output of which the pulses 37 act, and the master oscillator 27 are also connected in antiphase. In FIG. 2 alternation of operation of logic circuits 53 and 54 for consistency is shown by pulses of different amplitudes (time intervals a and axis).

Thus, the pulses 39, 40, 41, 42 are applied to the control electrodes of the thyristors 10, 11, 12, 13, respectively.

The operation of the demodulator is considered on the basis of one bridge rectifier 10, 11, 12, 13. which operates at a positive half-wave of current 31 (time intervals apia),

the processes occurring during the operation of the counter-parallel-connected bridge 14, 15, 16, 17. operating at the opposite half-wave of the current (intervals -ani, -ai, i), are similar to stern-recurring.

At the moment of time when the current 31 goes through a zero value and becomes positive, the bridge 10, 11, 12, 13 is switched on with rectifier mode. The voltage 36 of the secondary winding of the high-frequency transformer I at this time point is positive and polar corresponds to the polarity shown in FIG. 1 without brackets. The logic circuits 24 at the same time pass control pulses only for two transponders

11. 13 that open and the load current flows through the peep; (+) transformer secondary winding 1, thyristor 11, ftl 18, load 19, sensor 21, filter 18, thyristor 13, (-) secondary winding. The time frames 43. 44, 45, 46 of the conducting (closed and ground) and nonconducting (open) ground states of the thyristors show that, in the time interval ti - tz, there are thyristors in the conducting state

Claims (1)

And, 13. At time 4, high-frequency voltage 36 reverses its polarity (shown in brackets in Fig. 1), creating conditions for switching on thyristors 10, 12, but unlike (prototype) the control pulse 40 enters only to the thyristor 12, which, including, switches the thyristor II and short-circuits the transducer 19, creating a circuit for the flow of the reactive load current but: load 19, sensor 22, filter 18, thyristor 13, transistor 12, filter 18, load 19. Since in the time interval / 2-ts, the thyristors are 12, 13, and the thyristors 10, 11 are closed, then m The tuner with a high-frequency transformer goes into idle mode for a specified time. When the control angle Or is reached, the converter 10 receives a normal pulse 42, the thyristor turns on, the thyristor 13 switches, and the transformer 1 is connected to load 19 again, the current in this interval r3 4 flows along the following values: (+) transformer secondary winding, thyristor 12, filter 18, load 19, current sensor 22, filter 18, thyristor 10, (-) transformer windings. At time / 4, the voltage of the secondary winding of the transformer changes its polarity again, creating the conditions for turning on the thyristors 11, 13, however, only the thyristor 11 switches on to the control pulse 39, the thyristor 12 switches, the load shorts up again, idle mode. When the control angle ap is reached, the thyristor 13 is turned on and the load is connected to the secondary winding of transformer 1. The processes described above are repeated until the supply voltage of the network 30 does not replace its polarity, from which moment the rectifying bridge 10-13 turns into inverter . His work should be considered from the previous high frequency period when the bridge was still operating in the rectification mode. The control pulses 40, 42 arrived at the thyristors 12, 10, and the load current was described in the above circuit for the case when the polarity of the applied secondary winding of the transformer corresponded to the polarity shown in FIG. 1 in brackets (time interval When the mains voltage goes through zero, the voltage of the secondary winding of the transformer changes its polarity, thereby creating conditions for switching on the thyristors 11, 13. However, the control pulses 40, 42, due to the logic elements And (see Fig. 2) post on those thyristors that were included in the previous half-cycle of high frequency, i.e., on thyristors 10, 12. For this reason, the current determined by the active-inductive nature of the load will continue to flow specified chain but now meet in the case of the secondary winding of the transformer, since the polarity of this voltage has changed (shown in Fig. 1 without brackets). When an advanced control angle PP is reached, the logic cell transmits a pulse 39 to the thyristor I, which, including, switches the thyristor 12 and short-circuits the load-voltage on the load is equal to 5 10 15 20 25 30 35 40 45 50 55 60 65. At the time t, the control emulsion 41 from the winding of the master oscillator goes to the thyristor 13, which switches on and switches to the thyristor 10 bridge to rectification mode. After a while, the polarity of the secondary winding of transformer 1 is reversed (in brackets in FIG. 1), and the bridge automatically switches to the inverter mode. The processes described below are repeated until the current changes its current. From this point on, a bipolarly connected bridge 14–17 with a neutral mode is switched on, since at the inputs 59 of the described logic cells (FIG. 4) the polarity becomes locking for both transistors 56 n controlling pulses during intervals a, 1 and OB on the bridge 10-13 will not come. In the other, the soils of similar cells connected to the control electrodes of thyristors 14-17, the polarity at said inputs 59 will be unlocking, and they will control this bridge in the same way. Thus, at the output of the regulator, a voltage 47 acts, which is controlled by a phase shift of the control pulses. It is obvious when considering thyristor switching diagrams that increasing the control angles ap and PP leads to an increase in the zero shelf tz-tz, and consequently, to a decrease in the output voltage. By changing the angles Op and pp from 0 to 180 °, the output tension can be adjusted from zero to the maximum value. Claims An alternating voltage regulator with a high-frequency link containing a thyristor modulator loaded on the primary winding of a high-frequency transformer, to the secondary winding of which a thyristor demodulator input is connected, a control system with a master oscillator and two controlled phase-shifting blocks, as well as input sensors and output connections and an output current sensor, characterized in that, in order to reduce the mass and improve the energy performance, about A valid parallel voltage inverter, as a demodulator, a direct frequency converter, and the control unit is equipped with an auto-oscillator connected via a delay unit to the master oscillator and connected to its outputs via the two-input logic circuits of the modulator, and the output of the input voltage sensor is connected to the inputs of the said "two-input" circuits and to the master oscillator; the outputs of the sensors of the output voltage and current are connected via three-input logic inputs e scheme "And ti9 Ristori demodulator, and other inputs of these circuits" And nodklyucheny to specify the generator of ge10 directly through said n fazosdvngayuschie blokn.  T lrw (j ef TTr   AND i I I J L-j UJ