A chronological transmission expansion planning method and its comparison with stochastic planning

We propose a chronological transmission expansion planning (Chr-TEP) model that includes the temporal constraints of thermal power units and considers the time series of wind power, solar power, and load demands. The basic idea of this model is to obtain the optimal planning scheme by simulating the actual operation of the future power system. We adopt a cyclic modeling approach to solve the computational feasibility problem and address the issue of redundancy in the planning scheme through the maximum net load shifting technique. We compare the proposed model with a two-stage stochastic transmission expansion planning (Sto-TEP) model by observing changes in planning schemes, costs, and computational time with different time spans of scenarios or cycles and various clustering methods. Case studies are conducted on Garver’s 6-bus, IEEE 24-bus, and IEEE 118-bus systems. The results show that due to the simulation of future system operation and the consideration of constraints that better align with actual operating conditions, the Chr-TEP model generally plans more lines than the Sto-TEP model to ensure the feasibility of future operation. In addition, when considering temporal constraints in the Sto-TEP model, its computational time increases significantly, while the Chr-TEP model has an advantage in terms of computational efficiency.