Integrated Robust Governor Technique for Hydraulic Generating Regulated System via Uncertainty Estimator based Sliding Mode Control

Abstract

ABSTRACT This paper proposes a new robust governor for an intricate and nonlinear hydraulic generating regulated system. The system embodies uncertain chaotic dynamics, hydro-turbine governor as a controller and hydro-generator as a controlled unit. In literature, various speed governor frameworks have been investigated for the asymptotic stabilization of generator speed with a highly conservative conjecture that the lumped system uncertainties should be known in advance. In order to obviate this conservatism, a new governor is synthesized in this paper, which amalgamates a terminal sliding mode control (TSMC) with an uncertainty and disturbance estimator. The paramount merits of the introduced technique are finite-time convergence capability of the selected sliding surface, hydro-electric station stability, and robustness without requiring the prior uncertainty knowledge. To support the efficacy of the proposed technique, the closed loop time domain performances are evaluated through four different critical tests, such as fixed point stabilization test, periodic orbit tracking test, variable speed deviation tracking, and robustness test to stochastic disturbances. Moreover, the obtained results are also compared with four previously established techniques, such as conventional sliding mode control (SMC), Proportional Integral Derivative (PID), PID-SMC, and fast terminal SMC. In contrast to the existing governing techniques, the proposed technique is also able to render better time domain performances, such as 77.39% decrease in settling time, 100% reduction in peak overshoot, 96.85% reduction in integral time of absolute error, 70.40% decrease in integral absolute error, and 46.01% decrease in CPU time of implementation.