Frequency-domain Analysis of A Modified Active Disturbance Rejection Control With Application to Superheated Steam Temperature Control

Superheated steam temperature (SST) systems face many control difficulties caused by unknown disturbances and high order dynamics. This is becoming more and more severe due to the rapid growing of intermittent renewable generation. To improve the tracking and disturbance rejection performance of SST systems, a modified active disturbance rejection control (ADRC) is proposed. Based on its equivalent structure, this paper develops the frequency-domain analysis of the modified ADRC to present the influence of parameters on the control performance. Then the modified ADRC based on the frequency-domain analysis is applied to the SST control to verify the superiority of the modified ADRC. Based on the results of the simulation and the field application on a power plant simulator, the modified ADRC can obtain the best tracking performance with a small overshoot and short settling time compared with other comparative controllers. Besides, the modified ADRC has the smallest fluctuation range of SST under the input disturbance and load varying conditions. The superiority of the modified ADRC ensures the satisfactory control performance and shows a great potential in industrial applications.