FIELD: electrical engineering.
SUBSTANCE: invention relates to the field of electrical engineering, in particular to systems and methods for increasing the reliability of the operation of an electric drive with a multi-level inverter based on the reverse conversion of the kinetic energy of the load electric motor into electrical energy by reducing the frequency at the output of the electric drive. The essence of the invention lies in the fact that when the supply voltage is lost, the electric drive is switched to the mode of maintaining a constant voltage of the DC link. In this case, the value of the supply voltage of the electric drive is continuously monitored, according to which the voltage (Ud) of the DC link of the electric drive and the value of the total current (It) of the electric motor are regulated.
EFFECT: improved reliability and accuracy of regulation of the system, which includes a variable frequency drive with an electric motor, in case of supply voltage dips.
5 cl, 4 dwg
