A consideration on rate of reactive power service from generators in liberalized power market

In recent years, the deregulation of electric power industry has progressed in the world. It contributes to reducing electric rates, but there is possibility that the power system might become deteriorated. Under the circumstances, ancillary services that maintain system reliability and security become more important. There are various services in ancillary services, for example long-term power reserves, power/frequency control, voltage/reactive power control and so on. In these services, it becomes a subject of discussion on how to procure and receive the services and how to pay money for the cost of the supply of ancillary services. In. this paper, we focus our attention on reactive power supply of ancillary services. Then, we propose a calculation method for the rates based on an improved Nodal Pricing, and consider rates of reactive power supply service from generators.