Putting unloaded transmission lines into operation is one of the main steps of network reconfiguration in power system restoration. Whether an unloaded transmission line could be restored successfully or not may have a significant impact on the speed of the whole restoration process. Given this background

an approach to determine optimal restoration paths for a power system is presented with the failure risk of restoring transmission lines taken into account. First

the factors having impacts on restoring transmission lines are analyzed

including the charging capacity and restoration time of the transmission lines. Then

the relative probability of line restoring failure is defined. Based on the severity of line restoring failure

the line restoring risk is defined. Considering that the uncertainty of the restoration time of the lines leads to the uncertainty of the line restoring outcome

two robust optimization models are presented to minimize the total line restoring risks

which are applied to the “series” and “parallel” restoration stages

respectively. The highly efficient commercial solver CPLEX 12.2 is next employed to solve the developed two robust optimization models. Finally

the New England 10-unit 39-bus power system is served for demonstrating the basic characteristics of the developed models and methods. This work is jointly supported by National High Technology Research and Development Program of China (863 Program) (No. 2015AA050202)

National Natural Science Foundation of China (No. 51377005)

Zhejiang Key Science and Technology Innovation Group Program (No. 2010R50004) and State Grid Corporation of China (No. 5211011306TB).