| 摘要 |
PURPOSE:To decrease torque ripple to be generated from an induction motor, so as to make a good riding comfortableness without any car vibration by correctly detecting the voltage of a variable frequency voltage on an inverter side and then matching the ignition of a main switching element to a real PWM pulse pattern. CONSTITUTION:An elevator controlling device is constituted by providing an inverter 3 in which a plurality of switching elements are respectively bridge- connected to each other and an inverter controlling device 14 for producing a PWM pulse train according to the output power command, and for drive- controlling the switching elements according to the specific order. And output voltage of the inverter 3 is detected through a filter 19, and a zero-cross point is detected by a zero-cross point detecting means 20, and the detected phase lag by the filter 19 is corrected from the inverter frequency command information, so as to detect the real zero-cross point. And then the bias state of the switching element is so detected as to correct the pulse length of the PWM pulse. Thereby ripples of output voltage and current of the inverter 3 can be decreased. |
