电网低频故障对核电机组运行安全的影响分析

Operation safety analysis of nuclear power unit under power grid low frequency fault conditions

外部电网故障会对核电机组运行产生影响,建立合适的核电机组仿真模型对研究电网与核电机组的相互影响具有重要的实用价值。本文基于等值建模方法建立了M310堆型核电机组整体模型,并针对冷却剂主泵对电网频率变化敏感的特性在主泵模型中引入了电网故障接口,该模型有效性通过与设计手册中工况的对比得到了验证。结合机组涉网保护措施,进行电网低频故障对机组运行影响的仿真分析,结果表明:电网发生频率降低速度较慢的低频故障时对堆芯热工参数影响会较明显,但在机组的运行安全保护措施下不会对机组运行安全产生危害。

External power grid fault will affect the operation of nuclear power units.It is of great practical value to establish a suitable simulation model of nuclear power unit to study the interaction between power grid and nuclear power units.Based on the equivalent modeling method,the whole model of M310 reactor unit is established,and according to the sensitivity of coolant main pump to the change of power grid frequency,the power grid fault interface is introduced into the main pump model.The effectiveness of the overall model of the unit is verified by comparing with the working conditions in design manual.Combined with the power grid protection measures of the unit,simulation on the influence of low frequency fault on the unit operation is carried out.The results show that,when a low frequency fault occurs in the power grid with slow frequency reduction rate,the influence of the fault on thermal parameters of the reactor core is obvious.However,under the operation safety protection measures of the unit,there will be no harm to the unit operation safety.