Automatic Protection System of Neutral Wire-broken based on Supply-side Protection

Neutral wire is one form of distribution lines for faults. Neutral wire will cause the neutral potential shift and increase the voltage, which may endanger electrical appliances and persons. The entire existing neutral wire automatic protection device are to protect the load side and there are not protective measures on the supply side. Has load protection side. The research of the protection system is that Bi-directional zero-phase method will be taken to obtain the voltage and current square wave after the emergence of neutral wire of the load side. Then each wave is sampled and the phase difference is calculated by microcomputer control system, which will be combined with the neutral current change detection to cut off the power of supply side and achieve the automatic protection. The system can well achieve automatic protection of neutral wire on the supply side.