| 摘要 |
PROBLEM TO BE SOLVED: To ensure a stable operation at the time of saturation of output volt age. SOLUTION: An excitation-current command Id' and a torque-current command Iq' are output, and an induction motor 4 is supplied with an AC current from an inverter 13 so that an excitation-current detecting value IdFB displaying an excitation current and a torque-current detecting value IqFB indicating a torque current reach command values respectively. When output voltage from the inverter 13 is not saturated, the excitation-current command Id' is kept constant. When the output voltage from the inverter 13 is saturated, both the excitation-current command Id' and the torque-current command Iq' are reduced. The excitation-current detecting value IdFB displaying an actual excitation current is reduced up to the command value, and the torque-current command Iq' is increased and a torque current is augmented by a section compensating torque shortage by the decrease of the excitation current. |
