An optimal restoration sequence of generating sets based on fuzzy vector projection was presented to determine the thermal power generating units′starting-up sequence during early stages of power system restoration. The internal and external factors which influence the restoration sequence of the generator were discussed based on existing results. Taking into account the fact that many constraints in the language have greater fuzziness and the trapezoidal fuzzy numbers in L-R forms have good compose operation properties, the fuzzy mathematics method was used to deal with a variety of factors that affect the boot sequence units. The optimal restoration sequence of generator was obtained by fuzzy vector projection between decision-making index vector, ideal solution and negative ideal solution with normalized trapezoidal fuzzy numbers in L-R forms. The correctness and effectiveness were proven through the example of the calculation results.
