The New Dual Input DC Power Supply System

In the field of power system relay protection,the 220volts dc power supply is ofen used, and we often use the dual input power supply in order to increase reliability, however there are many shortcomings in the current dual switch switching circuit, for example,it needs a long time for the two power supply to switch when one of them fail to provide the electricity,besides , the two input power supply is not electrically isolated, and it exits switching noise and sparks when it is working. So it can not meet the requirements .This article describes a new type of dual input dc power system, and it gives the specific circuit diagram design and control strategies, and we has designed a 11kW dual input dc power supply which takes the TMS320LF2407A controller as the core controller. Finally, by means of simulation and experiments ,it shows that the new designed dual input dc power system has good reliability and availability, it meet the requirements well which is the zero-time switching and electrical isolation of the dual input power supply, it has high reference value in the field of power system relay protection.