| 摘要 |
PURPOSE:To maintain torque coefficient constant, by correcting the secondary resistance employed for slip frequency calculation such that a true value is provided at all times. CONSTITUTION:Controller for induction motor 3 comprises a vector control command operating circuit 1 and a power converter 2. The operating circuit 1 comprises a magnetizing circuit operating unit 20, a torque current operating unit 21, a two phase-three phase converter 23, comparators 26-28, a vector transforming unit 30, a slip frequency operating unit 31, an integrator 32, an adder 34 and the like, where the comparators 26-28 control output current of the power converter 3. Furthermore, a resistance compensating circuit 40 is provided in order to correct the secondary resistance R2 employed for slip frequency operation. A coordinate conversion circuit 25 converts the flux on a fixed shaft into the flux on a rotary coordinates, and the secondary resistance employed for slip frequency operation is corrected upon provision of a true value. By such arrangement, the secondary resistance is corrected to provide a true value at all times thus maintaining a normal vector control performance. |
