| 摘要 |
PROBLEM TO BE SOLVED: To prevent the overvoltage breakdown of an inverter circuit due to instantaneous regenerative energy.SOLUTION: A converter circuit (11) rectifies an input AC voltage. A DC link section (12) receives an output of the converter circuit (11) and generates a DC voltage including a pulsatile component according to the frequency of the input AC voltage. An inverter circuit (13) converts the DC voltage from the DC link section (12) into an output AC voltage by switching operation and outputs the output AC voltage to a motor (32). A control section (14) controls the switching operation of the inverter circuit (13) so that the difference between the current phase (&bgr;) and the voltage phase (δ) of the motor (32) is less than or equal to a predetermined phase threshold value. |
