Available transfer capability analysis method of AC–DC power system based on security region

Available transfer capability (ATC) refers to the reliable power transfer capability for further commercial activities in the system based on current protocols. Traditional ATC method such as continuation power flow (CPF) can calculate ATC only based on a specific direction of load and generator, optimal power flow (OPF) cannot acquire accurate value of the intermediate calculations and have difficulty taking power system stability into account. Here, a novel ATC analysis method of AC–DC power system based on security region was proposed. First, the static security region (SSR) of AC–DC power system considering stability and security constraints of AC–DC power systems and adjustment of HVDC control were presented. An ATC analysis method of AC–DC power system based on security region was then presented. A comparison between ATC based on security region and traditional method was made. Security region under different HVDC controls and its influence on ATC was analysed. Case studies indicated that the method proposed here can acquire optimal generation direction, the adjustment process of HVDC control and the ATC of AC–DC power system, providing reference for power system dispatch and operation.