Higher Order Sliding Mode Observer Based Super Twisting Load Frequency Control with State and Input Time Delay

Abstract

In this article, a novel load frequency problem in single area power system is addressed with time delay in the state and control loop. Increasing use of communication channels and DSP based controllers introduce time delay in states and control loop. The presence of time delay can worsen the performance of the controller and often are the source of system instability. The proposed control scheme comprise of a state observer based controller using a delay predictor. The state observer estimates the system states from the available output and control signal. The super twisting control (STC) guarantees finite time convergence of frequency under load disturbance with chattering free control signal. The merits of the work lies in the robustness and finite time convergence of frequency deviation using chattering free control with time delay. Random step load disturbance, process noise, nonlinearities like generation rate constraints (GRC), governor deadband (GDB) and integration of wind energy have validated the proposed design.