HUANG Yue-feng，XV Zheng
（Department of Electrical Engineering，Zhejiang University，Hangzhou 310027，China）
Abstract：Aiming at the capacity of nuclear power generating units is generally larger than that of thermal power generating units，theoperational characteristics of nuclear power generating units are different from those of thermal power generating units，and the proportionof nuclear power rises in the power system which will cause a series of stability problems，a relative simple mathematical model of nuclearpower generating unit was established on the basis of previous detailed models，which can be used in medium-term and long-term power
systemsimulation.ThroughthetransientstabilitysimulationofthesinglemachineinfinitebussysteminSimulinkthemechanical outputand other relevant variables of nuclear power generating unit were observed.Thresultindicatethatintransient stability simulation themechanical output and other relevant variables change little. So the mechanical output can be treated as a constant. This will greatlysimplify the mathematical model of nuclear power generating unit in power system transient stability simulation.
Key words：nuclear power generating unit；mathematical model；medium and long term stability；transient stability