SU498612A1 - Power source - Google Patents

Description

one

 The invention relates to the field of converter technology and can be used in rectifier units with an output LC filter for supplying low-voltage radio circuits.

The known power sources containing a thyristor rectifier with an LC filter at the output and a continuous control system consisting of a synchronizing organ and a phase-shifting node, which includes a sawtooth generator with a key transistor and an output organ, are characterized by large deviations of the output voltage during shedding and overload, due to the inertia of the filter and the inadequate speed of proportional control systems.

In the proposed power supply, this disadvantage is eliminated due to the fact that the source is equipped with two discrete action channels, one of which contains a capacitor bank connected through a resistor to the input of an LC filter and through a series-connected choke and discharge thyristor to the output of the thyristor rectifier and organ control, consisting of a series-connected element of selection of a jump of the load current when it is thrown, an amplitude selector, an element of setting a time of operation of a discrete channel, which Connected to the emitter of the key transistor of the phase-shifting node and the driver of the control pulse of the thyristor, the capacitor bank capacitance being equal to the capacitor of the filter, and the other correction channel contains series-connected elements that highlight the load current jump, reset amplitude selector element and connected to the base of the key transistor of the phase-shifting node through an uncoupling diode.

FIG. 1 is a schematic diagram of a power source; in fig. 2, 3 are voltage diagrams with decreasing (FIG. 2) and increasing (FIG. 3) loads. The unit contains a thyristor transformer-rectifying unit 1, to the input of which are connected: RC-circuit 2, 3 with choke 4 and thyristor 5 in the capacitor discharge circuit; LC filter 6, 7, load 8. The device of discrete regulation at

the reduction of the load current contains a current transformer 9 with a diode circuit 10 of the selection of load jumps with its decrease, connected to one of the inputs of a balanced diode-regenerative comparator 11, the second input

which is connected to a voltage divider

12, and the output of the comparator is connected to the input of the extender — the underlying multivibrator.

Proportional voltage deflection of the rectifier is performed by a controller containing a synchronization unit 14, a phase shifter consisting of T | rigger 15, a sawtooth voltage generator 16, a comparison circuit of a balanced diode-regenerative comparator 17, an output device 18, a measuring unit 19 and a DC amplifier iiU. The output of the expander 13 is connected to the input of the sawtooth generator 15 in proportional control.

The discrete control device with an increase in the load current contains a current transformer 21 with a diode selection circuit 22 load jumps when it is increased, connected to one of the inputs of a balanced diode-generator comparator 23, the second input of which is connected to the voltage divider 24, and the comparator output is connected to the input the extender is a standby multivibrator 25. The output of the extender 25 is connected to the emitter of the key transistor of the saw-tooth generator 16, as well as to the input of the relay amplifier 26, which controls iem thyristor 5.

The control system works as follows. At a certain output voltage of the rectifier 1 and the load current 8, the proportional regulator ensures the inclusion of thyristors with a certain phase angle.

With a sharp decrease in the load current, when a signal proportional to the amplitude of the current jump (Fig. 2aj at one of the inputs of the comparator 11, exceeds the voltage set by the divider 12 by another input, a comparative pulse is generated at the output of the comparator (Fig. 26), which in element 13 is converted into a signal of a given duration (Fig. 2c). Due to this signal, fed to the input of the saw-tooth generator 16, generation of tyrnstor control pulses is prevented (Fig. 2d} and, accordingly, the next t In the selected time interval, the rectified voltage at the input of the smoothing filter 6, / is formed by a voltage dip (Fig. 2e), which compensates for the corresponding surge voltage on the load 8 (Fig. 2e).

With a sharp increase in the load current, when a signal proportional to the amplitude of the current jump at the input of the comparator 23 (Fig. 3a) exceeds the voltage set at its other input using a divider

24, a pulse is generated at the output of the element 23 (FIG. 36). This pulse, after a corresponding expansion in element 25 (Fig. Sv), is used to switch the rectifier thyristors to the minimum control angle by applying a voltage difference to the emitter of the key transistor of the sawtooth generator 16. The voltage diagram at the output of the generator 16 for this case is shown in FIG. 3g. At the same time, the output signal of element 25, amplified and transformed in amplifier 2b, turns on the thyristor 5 in the capacitor 3 circuit and discharges the latter through the choke 4 to the load 8. The voltage diagrams at the input of the smoothing LC filter of the rectifier unit and the load are shown respectively on FIG. Rear and FIG. Ze.

Thus, the voltage dip at the output of the thyristor rectifying unit (the shaded area in Fig. Ze) is compensated by the discharge energy of the storage capacitor and the energy obtained by the stepwise switching of the thyristors switching on with a minimum angle.

Subject invention

A power supply containing a thyristor rectifier with an LC output filter and a continuous control system consisting of a synchronizing organ, a phase-shifting node, which includes a sawtooth voltage generator with a key transistor, and an output organ, characterized in that in order to reduce the output deviations during the reset and load ramping, the source is equipped with two discrete action channels, one of which contains a capacitor bank connected through a resistor to the input Lt -Filter and through the series-connected choke and discharge thyristor to the output of the thyristor rectifier, and the control consisting of successively connected elements of the selection of the jump current of the load at its inlet, amplitude selector, element of the operation time of the discrete channel that is connected to the emitter of the key transistor of the phase-shifting node and the control pulse shaper of the discharge thyristor, and the other correction channel contains series-connected jump selection elements load current when it is reset, the amplitude selector, an element for specifying the time of action of a discrete channel and is connected to the base circuit of the key transistor of the phase-shifting node through an isolating diode.

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