電気学会地域供給系統モデルにおける線路損失最小系統構成の算出

抄録

In Japan, local power systems (77kV) are served from the 275kV or 154kV substations. For enhancement of power supply reliability, the transmission lines are connected to several substations, and the operational configuration is radial. The local power system's configuration is determined by connecting and disconnecting transmission lines so as to keep the radial structure and satisfy the operational constraints. When a local power system has a number of transmission lines, many configuration candidates occurs. Recently, an IEEJ committee made a practical scale local system model (IEEJ Local System Model). Since IEEJ Local System Model has 76 transmission lines, the total number of configuration candidates is 2⁷⁶(=7.5×10²² approximately). In this paper, the authors try to strictly obtain the loss-minimum configuration under constraints such as substation capacity, line capacity and radial structure in IEEJ Local System Model. In order to obtain the optimal configuration, a new computation algorithm is proposed. In the proposed algorithm, the configuration determination problem is replaced as two combinatorial optimization problems based on the operational constraints (1)substation capacity, (2)line capacity and (3)radial structure). One combinatorial optimization problem (subprobleml) is to pick up all partial configurations satisfied with line capacity and radial structure constraints. The, other one (subproblem2) is to select the partial configurations so as to minimize total line loss under the substation capacity constraint. By using the enumeration method, subprobleml is solved. Subproblem2 is solved by using the reduced ordered binary decision diagram (ROBDD). Since the proposed method is based on enumeration and Boolean function, the optimality of obtained solution is guaranteed.