Quantitative analysis and optimization of primary frequency characteristic in isolated power grid

Primary frequency regulation of isolated power grid is significantly different with large power system. In this paper, based on the frequency change of isolated power grid, mathematical expressions of a dynamic process of primary frequency regulation are derived. And then mathematical expressions of the maximum frequency deviation, maximum rate of frequency change and static frequency deviation are got. The influence on the primary frequency regulation by generator frequency coefficient, the ratio of generator participating in primary frequency regulation, the generator inertia time constant, and the governor time constant is analyzed. Optimization method of primary frequency regulation by adding the acceleration feed forward is proposed. The method, which equals to increasing the system inertial time, reduces the maximum frequency change rate and the maximum frequency deviation. At last, the validity of this method is verified by the simulation of an isolated power grid.