| 摘要 |
PURPOSE:To improve the reliability of a static scherbius device by a method wherein the power supply voltage and the power supply frequency to be fed to an induction motor are monitored, and compensation is made for a power supply frequency variation within a predetermined range and the device is stopped when the variation exceeds the predetermined range. CONSTITUTION:An adjuster 46 produces an output signal corresponding to the difference between the current target value from a current target value current detector 48 and the detection signal, and this signal is fed to an ignition control device 50. When a control device 54 detects a power supply frequency variation exceeding a predetermined value or a predetermined value of power supply voltage variation, on output signal is given to the ignition control device 50 and an ignition device 60, which ignites a thyristor switch 56., and a power inverter 36 is stopped. |
