SU143892A1 - Device for controlling the speed of rotation and reversal of a two-phase asynchronous motor - Google Patents

Description

Known schemes for controlling the speed of rotation and reversal of a two-phase asynchronous motor using contactless booster devices.,;

The proposed device differs from the known ones in that it allows to increase the speed of the control system and reduce its weight and dimensions. This is achieved by using two DC / AC semiconductor converters with an adjustable phase as the booster devices. The secondary windings of the transducers are connected between the AC network and the primary winding of the output transformer, which has a midpoint terminal, and the motor control winding is connected to the secondary winding of the output transformer.

A second option has been proposed for switching on booster semiconductor converters, in which the secondary winding of one of them is connected between the network and the control winding, and the second between the network and the motor excitation winding.

The proposed device is adopted for use in one of the products.

FIG. 1 and 2: two variants of the proposed device are shown.

In each arm of the circuit (Fig. 1), the primary winding / output transformer 2 is connected in series with the secondary winding of booster devices 3 and 4, for which semiconductor DC to AC converters are used; The phase of the voltage transformed in this winding with the help of the steel semiconductor converter 143892-2 is floating 180 °. , ,

The input signal is fed simultaneously to both fa- eury circuits of 5 and 6 transducers, and from these circuits to transducers 3 and. 4., power semiconductor converters applied rectifier 7, which eliminates the possibility of short circuit in the device in the presence of a control signal. The winding 8 of the engine control 9 is connected to the secondary winding 10 of the output transformer 2,

Thus, the load voltage is the geometric sum of the network voltage and the booster voltage. In the absence of a control signal, these voltages are equal and opposite in phase, therefore the output voltage is zero. At the maximum control signal, the phases of these voltages coincide and the voltage on the load is equal to the double voltage of the network. When the control signal polarity changes, the second voltage boosting device works, and the phase of the output voltage changes to the opposite, having reversed the motor 9.

In the second embodiment (Fig. 2), the secondary winding of the semiconductor converter 3 is connected in series with the network // to the winding 8 of the engine control 9, and the secondary winding of converter 4 is sequentially connected with the network to the winding of the engine 12. In this scheme, the reversal and regulation of the rotational speed of the motor is provided without the use of the output transformer 2 (Fig. 1), which reduces the size and weight of the device.

Subject invention

Claims (2)

1. A device for controlling the rotational speed and reversing a two-phase asynchronous motor using voltage booster devices, characterized in that the latter used two DC-AC semiconductor converters with an adjustable phase, the secondary windings of which are connected between the AC network and the primary winding of the output transformer made with the midpoint terminal, and the motor control winding is connected to the secondary winding of the output transformer. 2. In order to reduce the size and weight of the device according to claim 1, the secondary winding of one semiconductor converter is connected between the network and the control winding, and the second between the network and the motor excitation winding. Lll