The Real-time Reactive Power Pricing Model Considering Voltage Stability And Its Algorithm

How to price reactive power service is getting more and more important with the fast development of electricity market. The introduction of electric market competition mechanism in power system makes the network transmission capacity approach its breaking point and increases the insecure factor of the grid. Therefore, it is imperative to apply voltage stability into reactive power pricing, which is useful to ensure power system safe economic operation. The main work in this thesis is to solve reactive pricing problem considering voltage stability with immune algorithm combining multiple centrality corrections interior point method in power market.Firstly, the reactive service and reactive power market are elaborated in detail and the operation pattern of reactive power in foreign electricity market is introduced. Meanwhile, the existing reactive power pricing methods are analyzed. On this basis, a new model for real-time reactive power pricing considering voltage stability is proposed. In the proposed model, line voltage stability index is deduced by using circuit theory. Based on this index, the weakest voltage branch can be quickly found. The voltage stability index used as constraints condition is introduced into reactive pricing model so as to consider the influence of voltage stability to reactive power price. This is helpful to guide users to rational consumption and improve the safe and economic operation of the system.Secondly, the interior point method used to solve OPF is simply introduced the shortcoming of traditional interior point method is pointed out. Then a new method which combines the adaptive immune algorithm with nonlinear multiple centrality corrections interior point method is presented for the reactive power pricing. As a result, the computing time is saved and it leads to the optimization of calculation speed and convergence. It's suitable for online application. The proposed method is tested on several systems and the numeric results demonstrated its validity.Finally, the simulation results of the IEEE-14 bus system and the IEEE-118 bus system show that the proposed method is reasonable and feasible.