Probability-based circuit breaker modeling for power system fault analysis

Circuit breakers are widely applied in power system protection by interrupting fault current. Among all types of circuit breakers, we focus on the modeling of thermal-magnetic circuit breakers in this paper. Data regression and curve fitting methodologies are employed to study the manufacturer's time/current data. A brand new simulation model that contains probability tools is developed to realistically describe the tripping characteristics, and a product failure rate is also considered to reflect possible circumstances in real-world application of the thermal-magnetic circuit breakers. A simulation testbed system is included for the purposes of illustration and validation.