Fault Tolerant Control via Input-Output Linearization Method for LED-Driver Using a Boost Converter

Abstract

This paper proposes a method based on an input-output linearization controller with a nonlinear adaptive observer, in order to achieve both an effective light-emitting diode (LED) current tracking and an actuator fault tolerant controller strategy for a LED-driver, using a boost converter. The partial fault is presented as a Loss of Effectiveness (LoE) in the embedded control target by considering that it generates a faulty Pulse-Width Modulation (PWM) signal. Also, faults of energy storage components in the power system are considered as actuator partial faults. An internal stability analysis is presented to ensure the feasibility of the nonlinear controller design. The nominal feedback controller is able to compensate for the nonlinearity of the system exactly, thus yielding a linear control loop. Furthermore, a nonlinear adaptive observer is considered for fault estimation. When the actuator fault is detected and estimated correctly, fault accommodation and reconfiguration strategies are performed to reduce the fault’s effect. The controller and observer gains are tuned using genetic algorithm techniques to have a desired closed-loop and fault estimation error response. Finally, simulations results are done in order to illustrate the effectiveness of the proposed methodology.

Keywords

• Boost converter
• fault tolerant control
• genetic algorithm
• input-output linearization
• LED-driver