To provide an economical circuit breaker model system in which the opening and the closing conditions of simulation circuit breakers constituting the power system model of a power system simulator can be changed by the control device of the system during a test.

A circuit breaker model system BMS is composed of simulation circuit breakers RM1, etc., and a simulation circuit breaker control device BMC for controlling the simulation circuit breakers RM1, etc. Circuit breaker data DCB for appointing the time of opening and closing the simulation circuit breakers RM1, etc., is transmitted from a system control device SC and stored into the data memory means of the simulation circuit breaker control device BMC. When the simulation circuit breaker control device BMC receives a test starting signal from the system control device SC, it makes a control arithmetic means 1 execute a circuit breaker model control program P2, thereby outputting cut-off signals TS1, etc., or closing signals CS1, etc., to the simulation circuit breakers RM1, etc., in conformity with the circuit breaker data DCB.