The Research Of Reactive Power Pricing Basing On Marginal Cost And Power Flow Tracing

The appearance of power market brings forward many new problems about power system research. The market mechanism of reactive power service and reactive power pricing method become one of the hotspots being attention. It is difficulty that how to establish a reactive power market mechanism that can not only incarnate the character of reactive power service itself but also insure the security and stability of power systems. It is also difficult that how to establish a reasonable and executable pricing system for reactive power support.The market mechanism for reactive power service in the power market is investigated in this paper. At first, some contents correlative with reactive power market, such as the basic concepts and theories of power market, the items and character of reactive power service, and the current situations of the reactive power market overseas, are analyzed. Then the basic frame of reactive power market is proposed. The localized reactive power market is also investigated.This paper focuses on the pricing of reactive power service. Beginning with the principle and methods for electricity pricing, the existing methods for reactive power pricing and their advantages are summarized. Real-time pricing of reactive power can provide rich information about marginal operation cost of a power system, but doesn't guarantee recovery of revenue of reactive power generation. On the contrary, the pricing method based on composite cost allocation can guarantee recovery of the revenue, but fails to provide relevant economic information. Also investigated are optimal power flow (OPF) and power flow tracing used as tools of electricity pricing. A reactive power flow tracing method is proposed for further study of reactive power pricing.In order to overcome the defects inherent in the existing reactive power pricing methods, a new reactive power pricing method that combines organically real-time pricing method and cost allocation method is presented in this paper. The proposed method firstly allots the reactive power generation cost to each branch basing on the marginal cost theory. Then each branch's reactive power generation cost is further allotted to individual loads that use the branch basing on their reactive power flow traced. The reactive power cost and price to charge a load are thus obtained. The proposed method can guarantee the recovery of reactive power generation cost and provide relevant economic information. It remedies the defects inherent in the two classic methods. The simulation results of a 5-bus system and the IEEE 14-bus system show that the proposed method is reasonable and feasible.