Dynamic sub-transmission system expansion planning incorporating distributed generation using hybrid DCGA and LP technique

Since the emerging of distributed generation (DG) technologies, their penetration into power systems has provided new options in the design and operation of electric networks. In this paper, DG units are considered as a novel alternative for supplying the load of sub-transmission system. Thus, the mathematical model of considering DG on the expansion planning of sub-transmission system is developed. Fix and variable costs of the plan and the related constraints are formulated in the proposed model. The proposed objective function and its constraint are converted to an optimization problem where the hybrid decimal codification genetic algorithm (DCGA) and linear programming (LP) technique are employed to solve it. Solution of the proposed method gives the optimal capacity of substations; optimal location and capacity of DGs as well as optimal configuration of the sub-transmission lines. To demonstrate the effectiveness of the proposed approach, it is applied on a realistic sub-transmission system of Zanjan Regional Electrical Company, Iran, and the results are evaluated.

► DG units are regarded as new alternative in SSEP problem to supply load of subtransmission system.
► Mathematical modeling of DG for expansion planning of subtransmission system is developed.
► Model gives optimal capacity of substations; DGs sizing and sitting and network configuration.
► Composed expansion planning optimization problem is solved using DCGA and linear programming.