Risk Assessment for Transmission Network Planning Scheme based on Conditional Value-at-Risk

Power supply reliability is an important indicator for the transmission network planning department and the operation department. A large number of new energy access has brought more and more uncertainties to the power grid, which have a great impact on the power supply reliability of the transmission network. Therefore, it is particularly necessary to evaluate the power supply reliability after the transmission network planning scheme is formed. The traditional determinacy evaluation methods are becoming more and more difficult to meet the requirements of power supply reliability. Traditional risk assessment methods considering uncertain factors also have some limitations. This paper applies the Conditional Value-at-Risk (CvaR) method which is used in financial risk management to the risk assessment of the transmission network planning. The concept of Conditional Value-at-Risk of Energy Not Supplied (CvarENS) is put forward, which will be used as the risk indicator to evaluate the risk of the power supply capacity of a given transmission network planning scheme. Compared with traditional evaluation methods, CvarENS can effectively evaluate the power supply risk of a planning scheme from different levels by adjusting the confidence level. So we can control the risk of power supply capability in transmission network planning, the limitation of traditional risk assessment method is solved. Finally, the validity of the proposed method is verified by a case.