CONTROL METHOD FOR CVCF INVERTER

摘要

PURPOSE:To protect a machine by suppressing transversal current and to realize stabilized power supply in safety. CONSTITUTION:Voltage control loops 8-11 and frequency control loops 12-14 are provided for an inverter main circuit 1. CVCF control is normally performed through the control loops and when a comparator 17 detects that the output current of inverter exceeds a predetermined level, a switch 19 is closed to take an effective power component operated through an operating unit 15 into the frequency control loop. A reference frequency is then regulated depending on the magnitude and polarity of the effective power component to suppress phase difference between the inverter and other units including a rotating generator thus suppressing the traversal current.