Abstract:

With the construction of smart grid in China,the application of electronic circuit breaker is widely used.A dual core current transformer is used to sample the main circuit current,and an electronic release equipped with a LCD screen and buttons that can continuously adjust protection parameters is designed.Practice has shown that the designed release has high accuracy,a wide variety of protection types,and functions such as status display,self diagnosis,auxiliary input and output,historical logs,and communication,which meet the intelligent requirements of the smart grid for circuit breakers.

Key words: molded case circuit breaker (MCCB), intelligent release, dual coils transformer, Modbus-RTU communication