Study On The Spot Price

Chinese power industry is carrying out the trail of generation unbundling and the competition bidding, in order to introduce competition and open electricity market on generation gradually. Electricity price is the lever for regulating electricity market, so it is clear for its important. Recent years electricity price is becoming the hot problem to research for many experts. Depending on the balance of supplying and needing instantaneously and meeting safe running in power system, Spot price is provided and being a kind of theory on electricity price using the Short Run Marginal Cost Method.The paper first presents a survey and comparison to the electricity power of the abroad and our country. According to Chinese power industry, a new method for spot price definition is presented in this paper. This method is based on Schwepp F C's spot price active model, the reactive is added to it. The result includes active and reactive spot price.Secondly, the general of optimal power flow development is introduced, and the merits and shortcomings of each method are overviewed. The method of nonlinear optimal power flow is discussed mostly, and the successive quadratic programming is used for large scale nonlinear optimal power flow.According to the theory of spot price and the relation between spot pricing models and the optimal power flow(OPF), this paper presents the objective function of generation least fee, thinking about the limit on power balance and network, finally OPF can be used to calculatespot price because Lagrange multiplier is the same with active and reactive spot price. This paper also decomposes the formulation of spot price into different components corresponding to generation, loss and transmission limits. Then uses the diagrams to expatiate how to affect the spot price by the Lagrange multiplier.The steps of calculating spot price are below:(1) Input generation parameter on consuming, limits on running and primitive power flow data; (2): Run a simple Newton power flow; (3): input OPF termination criterion, and the objective function;(4): Use a successive quadratic to run optimal power flow, obtain the real-time prices of active and reactive power at each bus and Lagrange multiplier, then print the results.The numerical results of IEEE 14-bus test system are given to demonstrate the feasibility of the proposed method.