A new method to realize the relay protection of AOCT following IEC61850

The optical current transducer is gaining interest because of its obvious advantages over conventional current transducers such as immunity to electromagnetic interference, high dynamic range and ease of integration into future digital control and protection systems. As the digital substation has been the tendency of power system, the study of the interface between electronic transducer and the protective device has become a hot topic. This paper has executed the merging unit, which can collect the digital signal from the adaptive optical current transducer and has realized how to transmit the digital signal to the protective device following IEC61850 through Ethernet. The circuit board based on MSP430 and CS8900A has better integrated level and operates stably. This paper also designed the scheme to realize optical fiber line differential protection based on AOCT following industrial computer and Lab VIEW real-time system.