Patent ID: 6750629
Filing Date: 2004-06-15
Classification: H02P

Abstract:
A motor driving system for driving an induction motor with a rotation frequency detector, wherein said induction motor drives a load, and said rotation frequency detector detects a rotation frequency of said induction motor, comprising:a variable speed driving unit connected to said induction motor and having a capacitance at its output, wherein said variable speed driving unit rectifies first 3-phase AC power to produce DC power, and converts the DC power into second 3-phase AC power with a frequency, and drives said induction motor with the second 3-phase AC power; and an inverter control unit which generates a frequency instruction and a temporary current instruction based on said detected rotation frequency and a rotation frequency instruction at least, corrects said temporary current instruction based on at least one of first correction depending on a value of said capacitance and second correction depending on a predetermined frequency component of said temporary current instruction to produce a current instruction, and controls said variable speed driving unit based on said frequency instruction and said current instruction.