The impact of switching strategies on power quality for integral cycle controllers

Integral cycle controllers (ICCs) are used for load power control. ICCs are switched at an integral number of cycles to effect this control. The load current for such controllers has an impact on the distribution supply bus: the impact occurs for low frequency (subsynchronous) phenomena and high frequency (supersynchronous) phenomena. Subsynchronous impact includes flicker on the distribution bus, and supersynchronous phenomena includes supply transformer core loss. The management of these power quality issues is discussed in terms of selecting the controller switching strategy. An innovative concept of group frequencies is discussed.