Abstract: The significance of auxiliaries variable frequency reformation was presented. The electrical connection schemes of variable frequency speed control system were analyzed and studied. According to the comparison between two electrical connection schemes, the scheme of One Towing Two was recommended. Then the auxiliaries of power plant operated at optimum status by using the variable frequency speed control system, the equipment operation efficiency was raised, and the purpose of energysaving was realized.

Key words: auxiliaries of power plant, variable frequency speed control system, electrical connection, comparison