The lack fault phase protection of main circuit phase, three-phase imbalance protection； Rectifier bridge imbalanceworking protection； Low voltage protection of power grid； Perfect and reliable current limiting (intercepting), pressure limiting (section pressure) protection； Over current protection - any time more than current setting value, implement over current protection； Over-voltage protection - any time over voltage setting value, implementation of over-voltage protection； Low voltage protection of Controlpower supply. Low Frequency protection； Corresponding fault display function. Medium frequency power supply control circuit adopts the fully integrated circuit,of which two main patent technology is: an active high voltage electronic transformer (patent no. : 201420280467.1), and an active high voltage electronic transformer (patent no. : 201410232377 X).Power cupboard of the circuit breaker uses domestic well-known manufacturers of vacuum circuit breaker, completely solves the problem of the ordinary air circuit breaker, arc strike a light. Power circulating water with no carbon contained in the hose connection, than common enhancement conduit with high temperature resistance, resistance to electric wheel hot shot, the bend better sexual characteristics, greatly increase its service life.Inductance of intermediate frequency power supply is pouring type inductance, the inductance has been used widely, but the technology is from our company firstly , the patent is: a kind of intermediate frequency power supply with pouring inductance (patent no. : 201420280428.1), and a kind of intermediate frequency power supply with pouring inductance (patent no. : 201410232308.9). Power supply cabinet internal link uss copper platoon T2 which copper platoon guide, and passes the passivation of sand. All the electrical device or equipment should be insistent for hot and moist environment.