SU1062838A1 - Control device for single-phase voltage inverter - Google Patents

Abstract

A device for controlling a single-phase voltage inverter containing a control voltage source, an integrator and a comparator associated with a control pulse distributor, characterized in that, in order to expand the functional possibilities, the device is equipped with a voltage polarity switch, a clock generator. pulses, a two-bit counter, two threshold nodes, a disjunction and a counting trigger with installation and R and S inputs, the integrator output being connected to the parator and threshold nodes , the output of the first of which is connected to the R-input of the counting trigger, and the output of the second - to the 5-input through the disjunctor, the output of the counting trigger is connected via the polarity switch to the integrator, and the clock generator is connected to the counter, the low-voltage output yes about which is connected with the installation; the trigger input, and the low-order inverse output with a dialgon, the high-output counter of the counter is connected to the distributor. About © OE

Description

The invention relates to electrical engineering.

. A device for controlling pulse-width-controlled inverters (WID) is known, comprising a generator, an off-design ring connected to a decoder, in which each frequency is connected to the switching frequency of the valves, usually rigidly, while in most cases it is required to vary the frequency of the output voltage over a wide range at a constant switching frequency l

In the device with non-multiple ratios of the output and switching frequencies, the formation of a symmetric unipolar output curve. In the case of the inverter, there are considerable difficulties due to the fact that the polarity of the pulses of the output curve can be changed both in the pulse interval and in the pause interval. Such modes usually also lead to an overload of the switching circuits of the inverter valves.

Closest to the invention by technical essence is a device for controlling a valve converter, containing sources of reference and control voltages connected via an adder to a comparator, the output of which is connected to a key element of the integrator, the output of which is connected to a comparator. With direct use, it does not provide a realization of unipolar WID with a variable number of pulses over a half period and a certain order of change of polarity of pulses of the output curve. the voltage of the inverter 2,

The purpose of the invention is to expand the functionality of the device.

This goal is achieved by the fact that a polarity switch, connected to an integrator, a clock pulse generator, and a voltage switch are inserted into the device for controlling a single-phase voltage inverter containing a control voltage source, an integrator and a comparator connected to the control pulse distributor. a two-bit counter, interconnected, two threshold nodes, whose inputs are connected to the integrator output, a counting R5 trigger, the clock input of which is connected to the direct output, the low-order counter, ({- input c It is connected to the output of one threshold node directly, and the 5-input is via a disjunctor with the output of the second threshold node, the output of the counting trigger is connected to the voltage switch polarity, the inverse output of the younger discharge

the counter is connected to the disjunctor, and the high-order output is connected to the distributor.

Figure 1 shows the structural diagram of the proposed device; Fig. 2 shows timing diagrams for explaining its principle of operation (the output voltage is formed from five pulses over a half period).

The proposed device comprises an integrator 1, connected via a cmmparator 2 with a distributor of 3 control pulses. A control voltage source 4 is connected to the comparator input, threshold nodes 5 and 6 are connected to the output. The output of node 5 is directly, and node b via disjunctor 7 is connected to the KR inputs of the counting trigger 8, respectively, through the output switch 9 of the polarity voltage connected with an integrator 1. A 10-pulse generator is connected with a two-bit counter 11. A direct output of the low end of counter 11 is connected to a trigger input of trigger 8, an inverse younger output with a disjunctor. The output of the higher bit of the counter .and connected to the distributor

3 ..;

The algorithm of the device operation is based on the vertical principle of control. The closest voltage generated by the output of the integrator 1 is compared in the comparator 2 with the constant control voltage (Fig. 2a), the operation of the comparator causes the switching of the power inverter inverters, and at the times of the switchings the output voltage curve CDB of the output voltage curve is formed (Fig. 2b ). Threshold nodes 5 and 6 fix the maximum and minimum threshold voltage, respectively, and alternately switch trigger 8, the output voltage of which is shown in Fig. 26. Trigger 8 periodically switches polarity switch 9, the voltage of which has a stable value, integrator 1.

The proposed order of operation of the circuit takes place during the formation of the mid-quarters of the period of the inverter output voltage. At the boundaries of a quarter of a period, the indicated algorithm of the device operation is modified. At the beginning of the half-periods (moments t, 1h, figure 2), the counter 11 is set to a low-order zero, the 1-to-reverse low-order signal sets the trigger 8 to a position, which contributes to the pause in the output voltage curve at the beginning of each half-period (Fig. 2a, b). In the middle of the floor periola (time i2) younger counter bit 1

Claims (1)

DEVICE FOR CONTROLLING A SINGLE-PHASE VOLTAGE INVERTER, containing a control voltage source, an integrator and a comparator connected to a control pulse distributor, distinguishing it in that, in order to expand the functionality, the device is equipped with a voltage polarity switch, a generator clock pulses, a two-bit counter, two threshold nodes, a disjunctor and a countable trigger with installation and R and 5 inputs, the output of the integrator connected to the inputs of the comparator * and threshold nodes, the output of the first of which is connected to the R-input of the counting trigger, and the output of the second to the 5-input through the disjunctor, the output of the counting trigger is connected via the voltage polarity switch to the integrator, and the clock pulse generator is connected to the counter, the low-order direct output of which is connected to the installation ; ® trigger input, and the inverse output of the least significant bit - with a disjunctor, ·. the high-order output of the counter is connected to the distributor. Figure 1