Universal Circuit Breaker Control Unit Hardware Circuit And Electromagnetic Compatibility Design

Universal circuit breaker is used to protect electric power line and power equipment,itcontains intelligent sampling,calculation,judgment,analysis and diagnosis,store,record andsending protection instructions and display,etc.Through sampling and processing thesignal,circuit breaker alarms or disconnects according to the set point, which is to achievethe protection of circuit and equipment.Intelligent control unit is a key control device ofuniversal circuit breaker,so it is very important to study the hardware circuit of control unit.According to the specification function of control unit,the hardware circuit will bedesigned,included power supply circuit,current sampling circuit,voltage samplingcircuit,trip circuit,MCR circuit,ZSI circuit,communication circuit,display circuit,etc.Part ofthe hardware circuit will be optimized. Main internal and external interference sources ofthe control unit is analysised in the paper,electromagnetic compatibility design is made toreduce the interference.The prototype of the control unit will be made,then hardware circuit will be tested byoscilloscope.The test mainly includes power supply circuit test,sampling circuit test and tripcircuit test.After this, the control unit will be installed into universal circuit breaker to testits function.Finally,environmental test and electromagnetic compatibility test will be carriedon with the control unit.