Systematic Approach to Design a Finite Time Convergent Differentiator in Second Order Sliding Mode Controller

This paper presents a systematic approach to design a Lyapunov based super twisting differentiator.The differentiator will be shown convergent in a finite time whilst the relevant time is accuratelyestimated. This differentiator is the main part to establish the sliding surface in higher order slidingmode. The differentiator is used in the prescribed control structure to regulate pressures of hydrogen and oxygen of a nonlinear Polymer Electrolyte Membrane Fuel Cells (PEMFCs) to prolong the stacklife. The aim of the control strategy is to minimize and keep the deviation between the pressures ofhydrogen and oxygen. The deviation forms a sliding surface, where its appropriate differentiation is required in the control law. It is the reason for reconstructing finite time derivatives in a closed-loop control. Finally, simulation result and a comparative study verify the performance of the proposeddifferentiator and the control structure to provide convergent estimator in finite time

Keywords:

Finite Time Convergent , Nonlinear Modeling , Twisting Algorithm , Convergent Differentiator , Pressure Regulation