Probabilistic planning of transmission systems: Why, how and an actual example

This paper discussed the basic concepts, criteria, procedures and methods in probabilistic transmission planning. The main purpose is to capture probabilistic characteristics in power system planning including uncertainties in load forecast, generator locations, and random failures of system equipment. Two key steps in probabilistic transmission planning are probabilistic reliability evaluation and economic analysis. The basic procedures of the two key steps have been presented. The probabilistic transmission planning method adds one more dimension to enhance the planning process. An actual example at BCTC provides more insights and indicates that probabilistic transmission planning is a powerful means and can help save investment in planning while keeping an acceptable system reliability level.