Direct Synthesis-based optimal PIDD2 controller design for enhanced load frequency control in microgrid systems with fuel cells and diesel generators

Abstract

This study introduces a proportional-integral-derivative plus second-order derivative (PIDD2) controller, featuring an innovative multiplier to address time delays, utilizing the direct synthesis method (DSM) for load frequency control (LFC) in time-delayed microgrid (MG) systems. The parameters of the proposed PIDD2 controller are tuned using the direct synthesis method, an analytical tuning approach. In the proposed design method, the best values of PIDD2 controller parameters were found by using the integral of time-weighted absolute error (ITAE). The proposed design approach has been developed for four different scenarios of time-delayed MG systems and compared with existing studies in literature. Real system data were utilized to illustrate the relevance of the proposed design methodology in real-time systems characterized by unmodeled dynamics, measurement noise, parameter fluctuations, and stochastic load variations. Based on Monte Carlo simulations conducted under parameter uncertainties, the proposed PIDD2 controller demonstrated improvements of up to 55.22 % in the ITAE index, 20.19 % in settling time, and 33.73 % in overshoot. Moreover, it significantly enhanced system stability across different random load pattern segments, with Integral of Time weighted Absolute Error (ITAE) improvements reaching as high as 99.99 %. The findings of this study provide significant insights into enhancing the stability of MG systems and improving efficiency in energy management.