Safe and Efficient Polymer Electrolyte Membrane Fuel Cell Control Using Successive Linearization Based Model Predictive Control Validated on Real Vehicle Data

Abstract

In this paper, a polymer electrolyte membrane fuel cell (PEMFC) stack control study is presented. The goal is to track the transient power demand of a real fuel cell (FC) vehicle while ensuring safe and efficient operation. Due to the dynamically changing power demand, fast transients occur in the internal states of the fuel cell (e.g., pressure, humidity, reactant mass) leading to degradation effects (e.g., high/low membrane overpressure, reactants starvation) which are avoided by imposing safety constraints. Efficiency is considered in terms of internal voltage losses minimization as well as minimization of the power of the compressor used to pressurize the cathode. For solving the optimization problem of power demand tracking, adhering to safety constraints, and maximizing efficiency, model predictive control (MPC) has been chosen. Due to the nonlinearity of the FC system, a successive linearization based MPC (SLMPC) is used to control the FC throughout its operating region. Simulation results show that the power demand can be fulfilled while at the same time ensuring safe operation in terms of adhering to constraints and that the minimization of internal voltage losses and compressor power lead to an approximate 9.5% less hydrogen consumption than in the actual reference vehicle.

Efficient Two-Step Parametrization of a Control-Oriented Zero-Dimensional Polymer Electrolyte Membrane Fuel Cell Model Based on Measured Stack Data

“…The difference is that the adapted model has the property of analytical differentiability, which is the reason for its selection. This property is beneficial for various control methodologies [20,21], and parameter sensitivity analyses (Section 3.2). The model is a zero-dimensional physical PEMFC model, and Figure 1 gives a schematic overview.…”

Model-Predictive-Control-Based Reference Governor for Fuel Cells in Automotive Application Compared with Performance from a Real Vehicle

“…In the hybrid electric vehicle, the engine bay was replaced with a fuel cell system. The car is shown in Figure 2 and more information on it can be found in [29,30].…”

“…In this subsection, the model used for the study is briefly presented as the detailed derivation can be found in [29,30]. The model structure is shown in Figure 4.…”

“…In this subsection, the successive linearization framework will be presented and later on used by the controller. This way, nonlinear systems can be easily controlled using the concept of the successive-linearization-based MPC [19,25,27,28,30]. An illustration of the concept can be seen in Figure 6.…”

“…Since the model is nonlinear, the successive linearization technique was used [25][26][27][28]. For more detail regarding the model and the successive linearization-based MPC, the reader is referred to the authors' previous work [29,30]. The problem of state estimation is not treated in this paper for brevity.…”