HIGH VOLTAGE FREQUENCY TRANSFORMER FOR LAUNCHING AND CONTROLLING SPEED OF POWERFUL ELECTRIC MOTOR, HAVING ONE OR SEVERAL THREE-PHASED WINDINGS (ITS VARIANTS) Russian patent published in 2007 - IPC H02M7/521 H02P6/18 H02P6/22 

FIELD: electric engineering, possible use for powering, launching and controlling speed of powerful electric motor, for example, high voltage synchronous electric motors with working voltages of 6-10 kV and power ranging from hundreds of kilowatts to dozens of megawatts.

SUBSTANCE: in high voltage frequency transformer for launching and controlling speed of powerful electric motor, serially with phases of three-phased windings of electric motor connected are sources of auxiliary EMF, each one made in form of commutator. Commutator is composed of 4 fully controlled tubes with back conductance connected in accordance to one-phased bridge circuit. Capacitor is connected to direct currents outputs of bridge. Device for controlling tubes of each commutator contains phase shifting device, adders, voltage controller, capacitor voltage indicator and block for setting value of auxiliary EMF. Commutators may be made in accordance to circuit of three-level one-phased module or in form of several serially connected commutators.

EFFECT: provision of smooth electric motor launch, possible combined operation of electric motor with inverters powering it in modes close to optimal, due to change of shift angle between current and voltage of electric motor phases from leading to lagging, and also due to approximation of shape of phase currents to sinusoid.

2 cl, 42 dwg