Semiconductor device for starting a three-phase asynchronous electric motor from a single-phase network

摘要

A semiconductor device for starting a three-phase asynchronous electric motor from a single-phase network is intended for use in an electric drive to power asynchronous three-phase electric motors, the stator windings of which are connected according to the "broken star" scheme. Two semiconductor switches of the device are formed by counter-parallel pairs of semiconductor elements made in the form of transistors. The stator windings of the electric motor are connected as a “torn star”. In the first semiconductor key, the collector of the first transistor is connected to the emitter of the second transistor and connected to the beginning of the second stator winding, and the emitter of the first transistor is connected to the collector of the second transistor and with zero supply network made in the form of a single-phase AC network for supplying a three-phase asynchronous motor. In the second semiconductor key, the collector of the third transistor is connected to the emitter of the fourth transistor and connected to the beginning of the third stator winding, and the emitter of the third transistor is connected to the collector of the fourth transistor and with zero supply network. The end of the second stator winding is connected to the end of the third stator winding and is connected to the phase of the supply network. The end of the first stator winding is connected to zero of the supply network, and the beginning of the first stator winding is connected to the phase of the supply network. Significantly increases the reliability of the device with increased efficiency.