Sliding Mode Without Reaching Phase Design for Automatic Load Frequency Control of Multi-Time Delays Power System

Abstract

The automatic load frequency control (ALFC) is designed based on integral sliding mode control (ISMC) without reaching time for a multi-time delay power system (MTDPS) with the system disturbances and uncertainties. In contrast with a recent method, the time delay of an area control error (ACE) signal and an interconnected signal are deliberated for the ALFC design in the MTDPS. The sliding mode is proposed with a selection of an integral single-phase surface and control rules such that the sliding state variables begin at the surface at the initial moment and converge to zero without reaching time. In addition, Lyapunov-based new linear matrix inequality (LMI) is applied to analyze the entire power system’s frequency steadiness. Moreover, the integral single-phase surface is advanced to improve the performance of the MTDPS. Using the proposed new integral single-phase surface approach, undershoot/overshoot and settling time were reduced compared to the recent (ISMC) approach. The results show the new scheme is highly robust in sliding variable’s fast convergence to zero asymptotical compared to the recently designed SMC. It has no significant interruption in operation, making its application in real power systems possible.

Keywords

• Automatic load frequency control (ALFC)
• multi-area power system (MAPS)
• integral sliding mode control (ISMC)
• multi-time delay power system (MTDPS)