| 摘要 |
PURPOSE:To hold the flux nearly constant at all times and to suppress the occurrence of vibration and noise, by controlling the voltage applied by calculating the flux of an induction motor in every instant so as to comply with the flux command. CONSTITUTION:The frequency command from a speed setter 4 is converted into the pulse train having a frequency 6f six times as much as the inverter frequency with a voltage/frequency converter 6 and sent out to a ring counter 16. At a ROM 10, the optimum switching signal read out of an output voltage table is sent to each switching element in accordance with the position signal from the ring counter 16 changing in every 1/6 of an inverter output period and the signals of incrementing magnetization, holding magnetization or decrementing magnetization from a ternary hysteresis comparator 15. |
