| 摘要 |
PURPOSE:To enable torque to be compensated for without exceeding the heat capacity of a converter by arranging a torque component current controlling circuit for limiting torque component current in the lowest speed area of a motor or at a stall time, and a field reference regulating circuit for increasing a field reference when the torque component current comes to a limit point. CONSTITUTION:The input of a speed feedback quantity omegar to a torque component current controlling circuit 44 and a field reference regulating circuit 45 is provided, and a speed is converted to a parameter, and each output is changed. By the torque component current controlling circuit 44, the current loads of respective converters are reduced by lowering the variable limiter characteristic (a) in the low speed area of a speed -n0-n0. Besides, in order to make up for short torque due to the reduction of the current loads, with the field reference regulating circuit 45, a field reference (b) is slowly increased from the normal value of 100%. |
