Electricity industries are being transformed worldwide, driven by the need for more energy, urbanization, scarcity of natural resources and global warming. Building a safe, reliable and highly stable power grid system has become an inevitable trend. The smart grid came into being therefore. Automatic control is an advanced modern communication technology. Automatic control system can improve network security and stability effectively, what refers to in the paper is a typical automatic control mode mentioned, the PI control, through theory and experiment we demonstrate the feasibility of improving the motor's stability by PI control.