| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem wherein no current flow to DC circuits and no current can be detected, thereby drive cannot be performed stably due to voltage drop close to 0 V when the capacitance of smoothing capacitors is decreased for miniaturization.SOLUTION: When a voltage decision means 115 determines that a pulsating bus voltage drops lower than a preset threshold, a control means 114 of controlling a voltage to be applied to a motor 106 from an inverter 105 energizes an output to the motor 106 for an extremely short time so that a DC current becomes a negative current, thus preventing the voltage between DC buses from dropping close to 0 V because the motor 106 charges the smoothing capacitor, detecting current even if the capacitance of the capacitor 103 is reduced extremely, thereby performing stable drive. |
