| 摘要 |
PURPOSE: To prevent a smoothing capacitor on the DC side of an inverter from being broken by the application of overvoltage, when a main switch is turned off by a fault, etc., during the operation of a motor. CONSTITUTION: The title driving method is a method for driving a permanent magnet synchronous motor at variable speed by an inverter 3 connected to a DC power source through a main switch 2 and a smoothing capacitor 4. A diode 7 is connected by a polarity which causes current to flow from the inverter 3 to the DC power source 1. The voltage of the smoothing capacitor 4 is limited to the voltage value of the DC power source by forming a circuit reaching the DC power source 1 from the smoothing capacitor 4 through the diode 7, when the main switch 2 is turned off by a fault, etc., during the operation of the motor 5A. |
