Elasticity modeling for transmission network expansion planning in deregulated power system

In deregulated power system, the transmission networks are experiencing significant changes in both the operational and expansion planning. Traditionally, transmission network expansion planning was based on minimization the total cost of energy delivering with a certainty level of reliability, and it is optimal under strict constraints. But some constraints and objectives are flexibility or elasticity due to uncertain in electricity market, the solution is insignificante in practice under strict constraints. This paper presents a new approach and model for transmission network expansion planning in deregulated power system. This method adopts elasticity constraints and elasticity coefficients for transmission network expansion planning, the main elastic factors node real power injection, circuit real power limitation and circuit investment cost are considered. The optimal solution is based on a certain belief level, it can overcome the shortcoming of strict constraints, and accords with the engineering practice. This Elaticity modelling method for transmission network expansion planning provides a new planning conceptual in deregulated power system.