An Analysis of the Effects of Flexibility Modification on System Frequency Regulation

With the flexibility modification of thermal power plant, the minimum technical output of units has been reduced. Different kinds of operating modes can be chosen by operators of power grids, which will influence the frequency regulation of power grids. The mathematical model of reheater steam turbine and load frequency control (LFC) are established considering flexibility modification of thermal power plants. Two scenarios are created and simulations are carried out. The results indicate that with the increase of units investigated in power system, the frequency deviation decrease obviously in both a stand-alone control area and two interconnected control areas. The conclusions presented here provide some guidance on operation of thermal power plants in regions to reduce the amplitude of frequency oscillation.