Higher Order Sliding Mode Observer – Based Fault Diagnosis in Automotive PEM Fuel Cell System.
This synopsis is about higher-order sliding mode observer-based fault diagnosis in polymer electrolyte membrane (PEM) fuel cell system. The PEM fuel cell systems have a potential to reduce pollutant emissions and dependence on fossil fuels as they consume hydrogen gas as a fuel and their major byproduct is portable water. They are promising candidate for automotive propulsion source due to their special characteristics of fast start-ups, light weight, low operating temperature and high power densities. In the last decade, control community has made great deal of efforts to enhance performance, effective monitoring and increase in durability of the system
A robust controller can enhance performance even in the presence of model incompetence, external disturbances and uncertainties. Immeasurable or difficult to measure model parameter can be estimated using model based observers. The observation can made health monitoring of the system possible. Fault diagnosis in the system preventing the system from entering faulty modes, can ensure the reliability and durability of the system
The higher order sliding mode technique is robust, fast convergent and chattering free technique. The robustness property of this technique can enable to detect faults on the basis of parameter estimation even in the presence of disturbances and uncertainties. Higher-order sliding mode observer, having property of unknown input, exhibited accurate parameter estimation that made this technique effective in low current densities and even in the no load conditions. There is no technique effective in such scenarios so far. Therefore the proposed technique would be a worthy contribution to the research.
The critical parameters are estimated using higher order sliding mode observers that include oxidizer mass flow rate and water content across the membrane of PEM fuel cell system. The results were verified by comparing with international bench model of PEM fuel cell system. The designed higher order sliding mode observers will be used for fault diagnosis in PEM fuel cell system. The fuel cell system is prone to faults i.e. water flooding and dehydration of membrane. The manifold leakage of hydrogen and oxygen result in fuel and oxygen starvation in the stack ultimately. The hydrogen leak is potentially dangerous fault also. Therefore the synopsis converges to do fault diagnosis in PEM fuel cell system using higher order sliding mode observers.