CONTROL METHOD OF AC ELECTRIC DRIVE Russian patent published in 2020 - IPC H02P25/02 H02P27/04 

FIELD: electrical engineering.

SUBSTANCE: in the AC electric drive control method, amplitude and frequency of the motor voltage are coordinated by means of relay voltage controllers by determining the motor current amplitude, adjusting the current at the inverter input of the frequency converter with an uncontrolled rectifier, for this purpose, by means of a relay current controller, the first fully controlled valve, which is located in the DC link between the rectifier and the reactor, is periodically switched on and off, and energy is transferred from the uncontrolled rectifier through the reactor and the inverter to the motor in a dosed way. At valve disconnection, current flow circuit is created by inverse diode introduced into DC link, in case of insufficient value of voltage at input of rectifier to obtain maximum voltage of motor, periodically by means of relay regulators and logical units switching on and switching off second fully controlled valve installed in parallel aiding input of inverter.

EFFECT: reduction of reactive power consumption, reduction of higher harmonic components introduced into the network, possibility to increase inverter output voltage higher than mains voltage.

1 cl, 1 dwg