Comparative analysis of external characteristics of nuclear power units and thermal power units

Abstract

In recent years, nuclear power units in China begin to participate in peak regulation and have a certain capacity of load tracking. These nuclear power units show different characteristics from those running with fixed load and share some similarities with thermal power units. The matured experience of thermal power units can be used on the operation of nuclear power units, so the quantitative comparison between both units is of great significance. For this purpose, modellings of both nuclear power units and thermal power units are established based on Power System Analysis Software Package (PSASP). After being connected to the same power grid, the response characteristics of the two units are tested respectively. The simulation results show that the load tracking speed of nuclear power units is lower than that of thermal power units, and their responses to external failure are almost the same. Furthermore, it is verified by comparison that the steam pressure is the main cause of the difference between nuclear and thermal power. Finally, it is proved that when analyzing the electromechanical transient process of large-scale power grid, a thermal power unit with the same output can replace the nuclear power unit for analysis due to their similar external characteristics.