Field control system for controlling induction machines

摘要

In a system for controlling field of an induction machine such that the torque of the induction machine is reduced in proportion to a running speed thereof a frequency-voltage converter converts the frequency of a pulse signal (fN or f) given from or to the induction machine into a voltage. A function generator varies the voltage into an output (VFG) of a predetermined variation characteristic. A multiplier multiplies the output with a reference value (I2) indicative of a desired torque. And a voltage-frequency converter converts the product into a frequency (fS) used for the control of the induction machine.