Reactive power evaluation and market power in liberalized ancillary services market

As result of electric power system liberalization, every ancillary service is worth economically. Clear and transparent rules should be determined for the evaluation of each service. Voltage control is very important ancillary services and therefore open market of reactive power becomes reality in deregulated power markets. All that has consequence in need for economic evaluation of reactive power. Also, because of location-based nature of reactive power and geographically very limited market, arises chance for so-called "market power". In this paper, one method of reactive power evaluation is presented with emphasis on market power measuring.