Real-Time Implementation of Maximum Net Power Strategy Based on Sliding Mode Variable Structure Control for Proton-Exchange Membrane Fuel Cell System

Increasing in the net output power of proton-exchange membrane fuel cell (PEMFC) systems is an important aspect of improving the performance of PEMFC. In order to enhance the net output power of the PEMFC system, the maximum net power strategy of the PEMFC system is proposed. Since the PEMFC system is a nonlinear system with time delay and uncertainty, sliding mode variable structure control (SMVSC) based on the exponential approach law is applied to achieve real-time operation at the maximum net PowerPoint. This article has two main contributions. The first major contribution of this article is to obtain the maximum net power surface of the PEMFC by multivariate fitting and to design the maximum net power regulator. The second major contribution of this article is to design a sliding mode variable structure based on the exponential approach law. The Lyapunov function is used to converge the sliding mode surface to the defined neighborhood. The advantage of this structural design is that the approach speed is gradually reduced from a larger value, and the response time is shortened. The control effect of the maximum net power strategy based on SMVSC is verified by the PEMFC experimental platform.