压水堆核电厂对电网低频振荡的影响

Effects of Pressurized Water Reactor Nuclear Power Plant on Low-frequency-oscillation of Power Grid

针对压水堆核电厂的运行特性,研究核电厂接入电网后对电网低频振荡的影响,这对于核电厂及电力系统的稳定运行与及时实施有效地控制具有重要的意义。利用特征值分析法搜索2015年湖北电网中与大畈核电相关的振荡模式,并通过矩阵束分析法对扰动后的电网功率振荡曲线进行模态分析与曲线拟合来识别电网发生扰动后的主导振荡模式,最后在与该模式强相关的大畈核电机组上配置电力系统稳定器(power system stabilizer,PSS)来达到提高系统阻尼从而提高系统稳定性的目的。仿真结果表明,扰动后会激发电网中若干弱阻尼振荡模式从而引起大畈核电及其邻近地区发生较大幅度的功率振荡,而PSS的合理配置可以有效地抑制低频振荡从而保证系统的安全稳定运行。

With respect to the operation characteristics of pressurized water reactor（PWR） nuclear power plants,the impact on power system low frequency oscillation when large PWR nuclear power plants integrated in the grid was studied,which had an important significance for the steady operation of the nuclear power plants as well as the power system and effective control application in real time.Eigenvalue analysis method was used to search the oscillation modes related to Dafan nuclear power plant in Hubei power grid in 2015.Then matrix pencil analysis was utilized to make mode identification and curve fitting of the power oscillation to identify the dominant oscillation mode after disturbance in the grid.At last,power system stabilizer（PSS） was installed on Dafan nuclear power plant strongly correlated to the dominant mode to enhance system damping,so as to achieve the purpose of improve system stability.Simulation results show that the disturbance can stimulate some weak damping oscillation modes in the grid which may lead to large amplitude power oscillation occurred in Dafan nuclear power plant and its neighboring areas,and the rational allocation of PSS can effectively suppress low frequency oscillation to ensure safe and stable operation of the system.