| 摘要 |
PROBLEM TO BE SOLVED: To surely restart an induction motor when coasting stably. SOLUTION: A vector control means for controlling an inverter 1 on a dq-axis rotatory coordinate system is constituted of a current command computing means 5 for computing a torque axis current command and a magnetic flux axis current command from a torque command and a magnetic flux command, a voltage command computing means 6 for computing a d-axis voltage command and a q-axis voltage command from at least a torque axis current command and a magnetic flux axis current command, an output frequency computing means 7 for computing the output frequency of the inverter 1 from at least one of the current commands, voltage commands, and phase current of an induction motor 2, an integrating means 9 for computing a phase by integrating the output frequency of the inverter 1, a gate control means 8 for controlling the gates of the inverter 1 from the phase and voltage commands, and an output frequency correcting means 10 for correcting the output frequency of the inverter 1, when restart of the induction motor 2 at which rising of magnetic flux is performed by the inverter 1 is performed, from its coasting state at which the frequency of rotation of the induction motor 2 is unknown, from at least one of the current commands, voltage commands, and phase current of the induction motor 2. |
