An expert microprocessor controlled voltage regulator for energy conservation and demand reduction in distribution feeders

A microprocessor-controlled voltage regulation system capable of controlling the voltage level on distribution feeders to reduce energy consumption and power demand was successfully built and tested in a laboratory environment. The compensator consists of a thyristor-controlled reactor (TCR) biased by a fixed capacitor. The reactive power injected into the feeder by the compensator is continuously controlled by adjusting the firing angle of the thyristors in the TCR, which results in continuous control of the feeder voltage level. The ability of the controller to distinguish between various types of loads and regulate the load voltage to a particular value for a specific load type was also successfully demonstrated. Harmonic suppression of the third and fifth-order harmonic currents produced by the TCR is also carried out using separate shunt filters. The filters also serve to provide the capacitive biasing of the compensator