Evaluation of available transfer capability in AC-DC hybrid power systems using point estimation

In deregulated market, available transfer capability (ATC) is a market signal refers to the capability of a system to transport above already subscribed transmission uses. It can provide significant information for power market participants. This paper deals with the evaluation of ATC for the integration of HVDC link with an AC power system. The computational model of ATC for AC-DC transmission system is formulated. Some numerical characteristics of ATC are estimated by robust statistic based on Monte Carlo simulations. The optimal power flow model is added into the repeated power flow method to consider both safe and economical operation. Sequential solution method is employed to deal with the AC-DC power flow. Case study with a modified IEEE 14-bus AC-DC transmission system is used and the program compiled based on MATPOWER in MATLAB R2008a. Several robust estimates of ATC indices are calculated. Comparison with the sample moments verifies the proposed method.