Studies on Dynamic Responses of Nuclear Power Plant during Frequency and Voltage Decays

계통주파수 및 전압 저하시 원자력발전소 응동 분석

The safety loads in a nuclear power plant perform a critical function to plant safety. The design of the electrical auxiliary system should ensure the availability and adequacy of the power supply, and therefore, the frequency and voltage relaying schemes should be installed on the system to monitor and protect against the degraded system condition. If unforeseen contingencies degrade the switchyard frequency and voltage to below the minimum values, the safety related bus should properly be transferred to alternate power source. This paper presents guidelines associated with the protection of nuclear power plants during frequency/voltage decay and the steady-state and dynamic analysis of auxiliary power system that should be performed to support the degraded voltage relay(second level undervoltage relay) setting.