
Switched-Reluctance Machines 7-11
7.4.1.4 A Control Strategy for Regulation of the Phase Current at Low Speeds
At low speeds where the induced EMF is small, a method for control of the phase current is necessary.
In the absence of such routines, the phase current will increase exponentially, possibly damaging the
semiconductor devices or motor windings. Hysteresis and PWM control strategies are commonly used
for regulating the phase current at low speeds. At higher speeds, the presence of a signicantly larger
back-EMF limits the growth of the phase current and there is no need for such regulation schemes. e
prole of the regulated current ...