
21-36 Power Electronics and Motor Drives
21.9 Summary and Conclusions
Today, a number of dierent control schemes for accurate ux and torque control of the IM are devel-
oped. is chapter has reviewed the basic control strategies for low and medium power drives of PWM
inverter–fed IMs. Starting from the space vector description of the IM, the control strategies are gener-
ally divided into scalar and vector methods.
• Scalar control is based on the IM equations at steady-state operating points and is typically
implemented in open-loop schemes keeping constant V/Hz. However, such a scheme applied
to a multivariable, coupled system like the I