POWER ELECTRONICS, RECTIFIERS, AND PULSE-WIDTH MODULATION INVERTERS:THE EFFECT OF INDUCTIVE LOADS ON PHASE ANGLE CONTROL

THE EFFECT OF INDUCTIVE LOADS ON PHASE ANGLE CONTROL

Real machines are inductive loads normally. This introduces new complications to the operation of the controller. Since inductors store magnetic energy, the current in an inductive

load cannot change instantaneously. This means that the current to the load will not rise immediately upon firing the SCR and will not stop flowing at exactly the end of the half- cycle. At the end of the half-cycle, the inductive voltage on the load will keep the SCR turned on for a short time, until the current flowing through the load and the SCR drops below IH (Fig. 9.29).