Highway power supply and distribution system is an independent system, is to the front of the system to serve to ensure the normal operation of the entire electromechanical system. It is generally used to centralized or relatively centralized power supply with power from the power plant or from the nearby area of the high voltage grid lead 10kV or 35kV high voltage sent to the highway substation of their own, with step-down transformer 220V/380V supply voltage, and then from the low voltage distribution screen and transmission lines sent to the relevant electrical equipment.