| 摘要 |
PURPOSE:To enable to correct torque control error due to variation in the temperature by assuming the temperature rise of a secondary coil from secondary copper loss and correcting by the result the slip angle frequency. CONSTITUTION:The output of a circuit 2 which generates a torque current is squared by a squaring circuit 31, and multiplied by a multiplier 32 by the output R'2/R20 of an adder 36. As a result, the output of the multiplier 32 becomes the amount which is proportional to the secondary copper loss which is produced in the secondary circuit. The temperature rise of the secondary coil is assumed from the amount which is proportional to the copper loss, and the slip angle frequency is corrected by the result. In this manner, the torque control error due to the variation in the temperature can be corrected even at the starting time or in the low speed range. |
