Effects of electronic ballasts on utility voltage stability

Some of the newer electronic ballasts have been designed to maintain constant light output and power demand during voltage fluctuations. Recent work has addressed the adverse effect that constant power electronic ballasts can have on demand curtailments during utility-controlled voltage reductions. The author builds on this previous work and explores a mechanism by which these constant power electronic ballasts tend to degrade utility voltage stability. Experimental findings comparing the electrical characteristics of magnetic and electronic ballasts are presented. Load models representing fluorescent lighting loads are developed on the basis of these findings. Conclusions are drawn concerning the potential for electronic ballasts to erode operational safety margins used to avoid voltage instability. Areas requiring further research are suggested.<>