Combined with 4-stage load rejection testing of unit No1 （700MW） at Zhuhai Power Plant

the design characteristics of overspeed limiting system of said unit has been analyzed

the design requirements of the overspeed limiting system discussed

the load rejection testing shows

though a number of electronic loops were designed in the said system

but the power nonequilibrium newly introduced to compensate the speed circuit not only enables the governor valve to be fast closed

but also ensures the system to have good response to load rejection under various load conditions.