Calculation Of Available Transfer Capability In Power Market

In power market environment, Available Transfer Capability (ATC) of power system is important index of transfer capability and system security. ATC refers to the maximum transfer capability of transmission network to power market. With development of power market, bilateral trade increase greatly. Study on ATC is a significant topic with much attention.In dissertation, a new smooth model for ATC calculation is developed base on smooth function theory. According to the new model, experimental studies on ATC computation of bilateral trade are carried out. Theoretical analysis confirmed that without considering the Saddle-node Bifurcation problem, this model could handle most of the non-smooth problem caused by enormous inequation constraints in power system.Traditional model of ATC consists of a set of equations with constraints. The larger the system is, the more enormous equations and inequations it consists of, and the harder to solve the ATC problem. Without considering the Saddle-node Bifurcation problem, the solution of ATC is mainly decided by those inequation constrains. There are too many inequation constraints and the one which is on the boundary is the key of ATC calculation. It is difficult to deal with those inequation constrains: the non-smooth property caused by transferring inequation constrains to equation ones and consequential vibration during solving process. To overcome it, based on the theory of smooth function, a new smooth ATC model is presented in this dissertation. The model gathers information of all inequation constrains into one equation. Non-smooth problem caused by inequation constrains can be avoided. Newton method is adopted in present dissertation to solve smooth ATC model. Numerical tests have been done on the standard IEEE-9/30/118 buses power systems and compared to traditional incremental method (one type of CPF methods). Results show that the new model and algorithm of this dissertation can find the boundary constraint reliably and quickly. It can easily be programmed and used in practical. It is efficient algorithm of ATC problem.