Parameter estimation of PEMFC system with unknown input

Abstract

This paper presents the synthesis of a model-based robust observer with an unknown input that observes a state (manifold pressure) of Fuel Cell System (FCS) in the presence of uncertainties. Using this observer the proportionality constant of the inlet manifold orifice is estimated. Then this estimated parameter is used to calculate the time varying air mass flow. As the mass flow rates of reactant gases play a pivotal role in the reliable and efficient operation of FCS. Their precise and exact value is necessary and important for the control and diagnostics of FCS. In the particular sense of inlet manifold of fuel cell system, appropriate air mass flow is very critical for the proper maintenance of chemical reactions taking place in the cathode and anode chambers. The sliding mode observer (SMO) with super twisting algorithm is utilized for the estimation of the mass flow rate of air despite the unknown input (load current). The estimates come out to be quite close to the nominal values. The simulation results show robustness to the uncertainties and fast convergence of estimates to nominal values of the parameter. The chattering phenomenon is attenuated significantly by employing higher order sliding mode. The standard SMO results are also presented for the sake of comparison. The proposed strategy is useful for sensor reduction, fault diagnostics and control.

Observer-Based Air Excess Ratio Control of a PEM Fuel Cell System via High-Order Sliding Mode

“…Finally, TEST 4 investigates the performance under the simultaneous effect of parameter uncertainties and noisy measurements. The operating range for the load current is 0-200 A, and the adopted current demand is I st (t) = 100 A for t ∈ [0, 15), 150 A for t ∈ [15,25), 120 A for t ∈ [25,35), and 190 A for t ∈ [25,45].…”

“…An important parameter that is useful to know in order to avoid faulty behaviors in the FC is the water content, and in [14], it was proposed to replace the humidity sensor by a properly designed first-order SMO. In [15], the proportionality constant of the inlet manifold orifice is estimated by means of an SMO, and this estimated parameter is used to calculate the air mass flow rate, which is useful for control purposes.…”

Control of oxygen excess ratio in a PEM fuel cell system using high-order sliding-mode controller and observer

“…Meanwhile, the bounds of the estimation error dynamics are overestimated due to consideration of the worst-case design during the state variations within set M in Eq. (16). Meanwhile, the parameters of the output injection law in Eqs.…”

“…However, the Kalman observer needs a linearized model with high accuracy that is still sensitive to uncertainties. This problem may be solved using Luenberger observers in state estimation [9,16]. In [17,18], a first-order sliding-mode observer was designed to estimate the states of a PEMFC system.…”

Fault Detection And Recovery For Spacecraft Formation And Attitude

“…Much like the above case with the broken super twisting sliding mode observer, the super twisting differentiator can be used for fault detection and various state estimation applications. In [Kazmi 2010], a sliding mode observer is used in parameter estimation for abnormal current levels in a fuel cell system with unknown inputs. In [Benallegue 2008], position, velocity and jerk are estimated from position noise corrupted measurements from an IMU.…”