| 摘要 |
PURPOSE:To enable to generate large torque at starting time and at low speed time and to eliminate the decrease in the efficiency of an induction motor at the constant torque time by outputting a strengthening field current reference from a function generator which varies on the basis of the secondary current reference. CONSTITUTION:An output IX relating to the secondary current is outputted from the secondary current reference I2* through a function generator 20, added by an adder 21 to a field current reference I0* to produce a strengthened field current reference I01*, thereby controlling an induction motor. Thus, the magnetic flux density of a motor can be maintained at rated value at a light load time to reduce iron loss and to perform the operation having less noise, and magnetic flux density is raised at the heavy load time. Accordingly, iron loss is large, but high torque can be produced with the same current. |
