With the rapid development of China's economy, a sharp increase in large-scale multi-user substation, for the security of supply and distribution system, real-time, ease of use and control of the power supply system and management put forward higher requirements. Originally applied to the high voltage transmission system, power monitoring technology has begun to be widely used 0.4KV low voltage distribution systems. In remote monitoring, digital protection, fieldbus, computer integrated management technology as the basic requirements of the low voltage intelligent power distribution system has been used as a standardized configuration in many areas began to spread.