Direct d.c. converter at the input side of a variable voltage variable frequency inverter driving an induction motor

摘要

The invention provides a control apparatus of a power conversion system for driving an induction motor via a VVVF inverter (5), wherein the AC voltage generated by the inverter (5) is increased so as to expand the high-speed side property of the induction motor, to thereby improve the performance during power running and regenerative braking. In the present system, a DC power supply source (10) having a power storage system (11) with a capacity capable of processing the current flowing into or out of the inverter is inserted in series to the ground side of the input of the inverter (5), and the output voltage thereof is controlled from zero in a continuous manner to be added to the trolley voltage, which is then applied to the inverter (5).