DEVICE TO CONTROL ELECTRIC MOTOR DRIVE Russian patent published in 2013 - IPC H02P6/08 H02P6/18 

FIELD: electricity.

SUBSTANCE: device to control an electric motor drive is made as capable of execution of high-frequency propulsion. The device of electric motor drive control comprises a three-phase bridge circuit to control a power supply phase so that voltage is inverted on terminals when power is unavailable by means of cyclic repetition of periods of power supply of positive direction, unavailability of power supply, supply of power of negative direction and unavailability of power supply. In case of high-frequency start the phase is adjusted so that voltage on terminals is inverted immediately after disconnection of power supply. If the required frequency of rotation is not achieved, the time of power supply is reduced. As a result the phase angle for actually applied voltage may be displaced forward, and high-frequency rotation of the system with weak field is realised. With sufficient voltage reserve the phase is adjusted so that voltage is inverted on terminals directly before connection of supply, and width of power supply pulse is adjusted so that phase ratio of power disconnection time and time of voltage inversion on terminals could be the required ratio, and the applied voltage and phase of current were optimised, and the maximum efficiency factor was provided.

EFFECT: provision of control of an electric motor with weak field.

10 cl, 8 dwg