抄録
Open access to electric power transmission networks has been carried out in order to foster generation competition and customer choice in the worldwide. Available transfer capability(ATC) is the largest additional amount of power above some base flow which can be transferred between two sets of buses under constraints such as voltage limit, overloads, stability and n-1 contingencies. Calculation of ATC is important to promote open access to electric power transmission networks. If there are several ATC between two sets of buses, simultaneous transfer capability(STC) of power transmission networks must be calculated. STC is defined as the ability of a transmission network to allow for the reliable movement of electric power from areas of supply to areas of demand. In this paper, a new algorithm to precisely calculate STC is proposed. The proposed method is based on linear programming(LP) based DC power flow and optimal power flow (OPF). Namely, LP base DC power flow is used to obtain the initial solution of STC, and then OPF using successive quadratic programming (SQP) is applied to obtain feasible solution of STC under the operational constraints such as balance of power supply and demand, voltage limit, overloads, generation limit, steady state stability and n-1 contingencies. Furthermore, if power wheeling transactions by several PPSs are simultaneously requested for the transmission network, it seems that the acceptable quantity for the requested wheeling power must be indicated to PPSs from a view point of the transmission network reliability. An algorithm to calculate the acceptable quantity for the requested wheeling power is also proposed by using STC computation. In order to check the validity of the proposed methods, numerical results are shown for 6 and IEEE 30 buses system models.
