With the expansion of power network, Power network stability problems have arised up, the short-circuit current of the device will also significantly exceeded. There exist many problems such as the reliability of power supply reduced, the threat of natural disasters of all the contact line among electromagnetic loop increased, etc. This article is to explore how to achieve optimal efficiency goals. This paper attempt to discuss this problem from the respect of technology and economics, using the Application of Optimal Control Theory to calculate the best model of electromagnetic ring. It is a useful discussion on the economic operation of power systems.