基于辨识模型的中间再热机组一次调频特性研究

Large-scale grid connection of generator sets will cause power grid load changes and generator tripping,resulting in power grid frequency fluctuation accidents and insufficient frequency modulation capacity.In order to solve this problem,a control strategy of coupling the control of high and medium pressure regulating valves of supercritical intermediate reheating units into the primary frequency modulation of power grid is proposed.In this paper,a supercritical intermediate reheat unit model is built on the MATLAB/SIMULINK simulation platform.Based on the measured data,direct LMS and indirect LMS are used to identify unknown parameters in the model and simulate the unit's participation in primary frequency modulation.The simulation results show that both the direct LMS and indirect LMS methods adopted have high identification accuracy,and the overshooting of mechanical power output can be reduced when the high and medium pressure regulating valves are controlled simultaneously and feedforward is added,and the primary frequency modulation requirements of the power grid can be met quickly,stably and safely.The simulation results under different conditions show that the performance of primary frequency modulation can be significantly improved by fitting the parameters in the model.