SU147667A1 - Device for controlling reversible single-phase asynchronous motor - Google Patents

Description

This invention relates to devices for controlling reversible single-phase asynchronous motors. There are known devices for controlling reversing single-phase asynchronous motors with two electrically not connected windings, one of which is an excitation winding, and the other one is an excitation winding containing a capacitor included in the excitation winding, and containing a capacitor included in the excitation winding, and one containing the excitation winding containing a capacitor included in the excitation winding, and containing a capacitor included in the excitation winding, and containing a capacitor included in the excitation winding containing a capacitor included in the excitation winding containing a capacitor included in the excitation winding, and containing a capacitor included in the excitation winding. transformers, the primary windings of which are included in the supply network, the voltage is series-consistent, and the secondary windings are connected in series but also connected to o.bmotke uiravleii engine.

The proposed device differs from the known ones in that the secondary winding of each transformer is shunted by a semiconductor controlled diode. Such inclusion in the controlled diode circuit provides an increase in the device speed, which makes it possible to use it to create high-speed follow-up drives.

The drawing shows a diagram of the proposed device.

TP1 and TP2 - trafic; UD and UDg - controlled diodes; D - the engine; C - capacitor.

The primary windings of transformers TP1 and TP2 are connected to the supply voltage network and are connected in series-according, and the secondary ones are connected in series to each other, and are connected to the control winding of the OS of the motor. With such switching on, the total output voltage on the secondary windings of the transformers will be zero if this maintains the equal turns of the windings Wi W and Wz-Wz.

Controlling the amplitude and phase of the output voltage is carried out with the help of two controlled diodes UD, and UD2, which shunt the secondary windings of the transformers. Diode control can

No. 147667 2 is implemented from any device, for example, from a push-pull, half-wave, high-speed magnetic amplifier, which provides a change in the firing angle of the diodes in the interval from zero to the half-period of the power frequency.

When a control signal Uyi arrives at the control diode UD, sufficient to fully open it, then this diode opens and bypasses the secondary winding Wz of transformer TP1. At this time, the current through the winding W flows only during one half-period, during the other half-period the current flows through the diode. Since the half-wave rectified current flows through the winding, the core of the TP1 transformer becomes saturated and its reactance becomes almost zero. In this case, a voltage is applied to the engine, determined by the ratio

IF / I - P

Ug-IF /

By selecting the intermediate values of the control signal Ut / i, it is possible to vary the conductivity interval of the LED diode from zero to HALF. the period of the power frequency, while the saturation interval of the core of the transformer TP1 will also change accordingly. As a result, the amount of voltage on the engine can be adjusted from zero to the full voltage of the network.

The motor reversal is performed by applying the control signal Uy2 to the controlled diode UD, the opening of which provides a change in the phase of the output voltage (the diode UD2 must be completely closed).

The time constant (speed) of the proposed device is determined by the time of magnetization reversal of the transformer core in the AC circuit, which, as is well known, is equal to one half of the supply voltage half-period.

Controlled diodes are selected for a current equal to half the load current, since only the half-wave rectified current flows through them.

Subject invention

A device for controlling a reversible single-phase asynchronous motor with two electrically unrelated windings, containing a capacitor connected to the circuit of one of the windings of the machine, and two transformers, the primary windings of which are connected in series to the network, and the secondary ones are connected anti-series and connected to the second control motor winding, characterized in that, in order to increase speed, each of the secondary windings of transformers is shunting controllable semiconductor diode meters