Pricing of generators reactive power delivery and voltage control in the unbundled environment

Reactive power supports by generators are essential for energy and reactive power delivery in the open access grid system. However, so far no fair scheme has been proposed that will enforce capital investment on the needed services, which may jeopardize the cause on power system deregulation. To devise such a scheme, the authors divide reactive support of generators into two functions-reactive power delivery and voltage control-and devise a payment framework to allocate reactive support cost of generators to the bidding loads and bilateral trades on the real-time operating point basis. In their method, the reactive sensitivity matrix derived from the fast decoupled power flow algorithm is used to determine the reactive delivery allocation pattern; meanwhile, efficient reactive loss formulae are developed to charge voltage control costs of generators. The authors demonstrate the potential of their method in a PoolCo. electricity market (EM) by numerical examples.