SU408437A1 - ADJUSTABLE RECTIFIER - Google Patents

Description

one

This invention relates to electrical engineering and can be used in controlled and stabilized rectifiers.

When powering stabilized and controlled rectifiers from a three-phase network, circuits are used, according to which symmetric thyristor controllers are included in each phase.

However, due to the low output power of low-voltage rectifiers (tens, units of hundreds of watts), the use of three single-phase regulators (taking into account control devices) makes the rectifier relatively cumbersome.

Using only one phase of the network when using one regulator; entails significant pulsations at the output of the rectifier, as a result, an increase in the dimensions of the filter, a decrease in the efficiency of the regulated rectifier.

The aim of the invention is to reduce the size of the filter and the ripple of the output voltage of the rectifier.

For this, the primary windings of the transformers are connected to different phases of the mains voltage through a regulator that is open for both transformers.

The invention is illustrated in the drawings.

FIG. 1 shows a regulated rectifier circuit.

Adjustable rectifier contains single-phase symmetric thyristor regulator 1, controller 2 control device 1, single-type power transformers 3, 4, full-wave rectifiers 5, 6, identical inductors (filter chokes) 7, 8, rectifier load 9.

If the inductances of the coils 7, 8 are not less critical, then the shapes of the voltages at the output of the rectifiers 5, 6 will be in the form of the oscillograms shown in FIG. 2a and 26.

Since the average values of the voltages at the output of the rectifiers remain equal to each other when the control angle is changed, a current flows through each of the filter chokes, the average of which is half the load current. The main hormones through the chokes are shifted in phase, which, adding up on the total load 9, give a reduced value of output voltage ripple.

Compared to a controlled six-phase rectifier, when three single-phase thyristor controllers are used, the volume of the proposed rectifier as a whole is significantly less - due to a decrease in the number of controllers and their control devices.

Subject invention

Adjustable rectifier with an adjustment range (0.5-1) / mag; c, powered by a three-phase AC line voltage, consisting of a single-phase symmetric regulator and two power transformers of the same type, loaded on full-wave rectifiers with identical inductive inputs, the outputs of which are connected through the inductor coils to one common output terminal of the rectifier, characterized in that, in order to reduce the size of the filter and the ripple of the output voltage of the rectifier, the primary windings of the transistor shaper connected to different phases -eg mains voltage through a controller, common to the two transformers.