Transmission surplus capacity based power transmission expansion planning

A power transmission expansion planning model with consideration of transmission surplus capacity and network load factor is presented. With traditional planning model, some transmission lines will operate on high load factors due to ignorance of the load levels of transmission lines. This may lead to network congestion or degrade the dispatch flexibility of future network. Traditional planning model has put more emphasis on investment cost rather than other aspects such as operation environment, transmission benefit, etc. The transmission expansion planning model in the paper aims to maximize network transmission surplus capacity and optimize network load factor distribution with least investment. Chaos Optimal Algorithm (COA) is introduced to solve this nonlinear integer planning optimization problem for its advantage of stochastic and ergodic searching characteristics. The effectiveness of proposed model and methodology is tested with two typical systems.