A decisive evaluation of parks transformation based commonly used voltage detection method

Abstract

The abc-to-dq0 based voltage detection technique is commonly employed in static transfer switch (STS) applications, which are targeted to protect sensitive loads against variety of disturbances. The technique is quite fast and precise especially in case of balanced disturbances. However balanced events seldom occur as compared to unbalances in supply system. Also there is every possibility that sensitive load may comprise of combination of single phase and three phase loads and therefore to offer a ride through capability during most of events, it is equally important to maintain good power quality at both single-phase and three-phase levels. The effectiveness and the capacity of the detection scheme are analyzed against common disturbances, routine operations of power system, under balanced variations which are within acceptable limits and against unbalances of hybrid nature (simultaneous presence of the sag and swell events). The impact of control elements on the detection process is also discussed.