Real-Time Flow Control of Blade Section Using a Hydraulic Transmission System Based on an H-Inf Controller with LMI Design

Abstract

Vibration and real-time flow control of the 2D blade section of wind turbines with three degrees of freedom (3-DOF), excited by external pitch motion, are investigated based on an H-inf (H∞) controller using linear-matrix-inequality (HIC/LMI) design. The real-time flow control for the purpose of aeroelastic flutter suppression includes not only the driving process of real-time physical equipment, but also the realization of real-time control algorithm in the physical controller. The aeroelastic system combined with pitch motion is controlled by a kind of HIC/LMI algorithm. The real-time external pitch motion is driven by rack-piston cylinder (RPC) using a hydraulic transmission system (HTS). The unsteady aerodynamic loads model is simplified by the HTS system. The HTS is actuated by a proportional-flow valve (PFV) which is controlled by another HIC/LMI algorithm, a novel algorithm for waveform tracking. According to the result of waveform tracking, the input current signal of PFV is realized by the configuration of the controller hardware system and its external circuits. In two types of HIC/LMI algorithms, controller stabilities are affirmed using Lyapunov analyses, and controller values are derived and obtained by using LMI designs. Flutter suppression for divergent and instable displacements is shown, with obvious controlled effects illustrated. An online monitoring experimental platform using hardware-in-the-loop simulation, based on Siemens S7-200 programmable logic controller (PLC) hardware and Kingview detection system, is built to implement pitch motion based on HTS and configure the signal input of PFV in pitch control.

Flutter Suppression of Wind Turbine Blade based on Adaptive Fuzzy Sliding Mode Control

“…Aeroelastic divergent unstable vibration is an important cause of blade fracture failure, among which the classical flutter caused by the coupled movement in flap/twist direction is one of the manifestations. The recent fracture failures of wind turbine blades all over the world have also verified this problem, so it is of positive significance to explore the method of suppressing the coupled flutter of blades [1][2].…”

Stability Control of Transport Robot Based on Iterative Learning Control

“…The characteristics of these robots are designed and embodied as ingenuity of structure with small size, simple motion, complete function and high reliability. The source of driving of these robots is often realized by pneumatic transmission and hydraulic transmission that just can match the control performance of PLC perfectly [5][6]. In the present study, a pneumatic manipulator used for loading and unloading sheet material is designed, with its stability analyzed.…”

Vibration control and trajectory tracking for nonlinear aeroelastic system based on adaptive iterative learning control

“…System modeling and aeroelastic control for divergent instability of stall-induced composite blades have been investigated based on pitch control using PID controller to reduce blade loads of wind turbine, with the pitch actuator performed by hydraulic transmission system. 3 A PID controller, aiming at achieving maximum power tracking and protect from high wind gusts, has been developed for pitch control of wind turbine blades by using electrohydraulic pitch actuation system. 4 In order to implement pitch control accurately, various intelligent control theories and advanced control methods, such as fuzzy control theory, neural network control (NNC), model predictive control (MPC) theory, sliding mode control (SMC) approach and other robust control approaches for instable system with uncertainties, have been frequently used in relevant research, either to achieve load mitigation control or to achieve maximum power acquisition.…”