Var Supporting Pricing Based On Branch's Dissipation Power Components

Reactive power support pricing is a fundamental and consequential part of reactive power management. Establishing the pricing mechanisms of reactive power service is important for the deregulated power industry both financially and operationally as the following reasons. Firstly, as a correct price signals, it is an important guidance for consumers to decide their behavior. Secondly, it can promote reasonable planning of reactive power supplies in order to enhance the system stability and reliability. Thirdly, it can improve the voltage quality. Fourthly, it can enhance economic efficiency of system operation.Much research work has been done on reactive power pricing. All of them can be divided into two categories:reactive power pricing method based on marginal cost theory and reactive power pricing method based on aggregate cost theory. In marginal cost theory, shadow prices which are obtained from the reactive power equal constraints of the OPF problem is regarded as the nodal reactive power pricing. The reactive power price based on the marginal cost theory can provide abundant economic information. However, this theory could not achieve payment balance between the cost and income of reactive power support. Even worse, the reactive power price of each node is not steady because of the difference of objective function or constraint condition. The aggregate cost theory changed the reactive power pricing problem into reactive power allocation problem. This method is concise and also can guarantee payment balance. However, this method neglects that different reactive power has different influence to reactive power price. Economic information is also lacked in this method.Based on the above analysis to marginal cost theory and aggregate cost theory, a novel method for reactive power support pricing based on dissipation power components is presented in this paper. Firstly, the traditional concept of reactive power support customer is broken, the load active power, generator active power and load reactive power are defined as reactive power support customer, meanwhile, the generator reactive power, synchronous condenser and also other reactive equipment are defined as reactive power sources in this method. Then each of reactive power sources used for var support is modeled by a shunt susceptance called "cost susceptance"; each of reactive consumers is modeled by each of their equivalent nodal injection current sources based on power flow solution. Finally, both reactive power fractions and var support cost induced by reactive power consumers on cost susceptance are determined based on the algorithm of dissipation power components. The unit var supporting cost is calculated, which is var supporting price of reactive consumers.A novel method for reactive power support pricing based on dependence and dissipation power components is presented in the pool model. Firstly, the sensitivity between reactive power loss and used power is used to quantize the dependence factor. And then, the reactive power support payment is divided into dependence payment and imputation payment. The dependence payment is allocated in proportion to the dependence factor and the imputation payment is allocated based on dissipation power components. The reactive power support payment and price of each unit active/reactive power are obtained by combining these two parts.Furthermore, a novel method for reactive power support pricing based on dependence and dissipation power components is presented in the pool/bilateral model. First, a general tranction vector referred to pool tranction and bilateral tranction is depicted. And then, the reactive power support is constructed as the combination of reactive tranction in pool model and active power tranction in bilateral model. The algorithm of dependence factor and dissipation power components is discussed in pool/bilateral model. Then, the dependence payment and the imputation payment of each tranction are obtained. At last, the reactive power support payment and price of each tranction are obtained.The calculation results of IEEE118 system and other test systems show that the method presented in this paper has these below characteristics:it is applicable for any transmission systems of looped configurations and loop flows; it doesn't need any assumption and simplification and takes account of the interaction between active and reactive power; it achieve payment balance between the cost and income of reactive power support and also has abundant economic information.