Intro
Supervisors' Foreword
Acknowledgements
Contents
Abbreviations, Nomenclature and Notations
Operators
General Convention
Specific Notation
Specific Observer Notation
Specific Fuel Cell Notation
Specific DC Microgrid Notation
1 Introduction
1.1 Thesis Objective
1.2 Thesis Outline
2 The Observation Problem
2.1 Problem Definition
2.2 Observability Analysis and Necessary Conditions for the Solvability ...
2.3 The Benefits of Observers
References
3 Nonlinear Observer Design
3.1 Observer Definition and Design
3.2 High-Gain Observers

3.2.1 Classic High-Gain Observer
3.2.2 Transformation to a Triangular Form
3.2.3 Extension of the High-Gain Observer: Low-Power Peaking-Free Observer
3.3 Parameter Estimation-Based Observer
3.3.1 Idea and Structure of the Observer
3.3.2 Standard Parameter Estimator
3.3.3 Implicitly-Regularized Observer
3.3.4 Transformation to a State-affine Form
3.4 Nonlinear Observers in the Presence of Unmodelled Elements
References
4 Adding Filters in Nonlinear Observers
4.1 The Conflict of Measurement Noise in Nonlinear Observers
4.2 On Adding Filters in Observers

4.3 Low-Pass Filters in Nonlinear Observer
4.3.1 Cascaded Filters and Iterative Filter Design
4.3.2 Filter Examples
4.4 On Internal-Model Filters
4.4.1 Problem Formulation
4.4.2 Main Assumptions
4.4.3 Internal-Model Filter
4.4.4 Combining Both Filters: Low-Pass Internal-Model Filter
4.5 Dynamic Dead-Zone Filter
References
5 Adaptive Observers: Direct and Indirect Redesign
5.1 Adaptive Observers and the Conflict of Model Uncertainty
5.2 Direct Adaptive Observer Redesign
5.2.1 Constructing a Strict Lyapunov Function

5.2.2 Addressing the Relative Degree Condition: A High-Gain Observer Approach
5.2.3 Library-Based Adaptive Observation: A Sparsity-Promoting Adaptive Observer
5.3 Indirect Adaptive Observer Redesign
References
6 PEM Fuel Cell Monitoring
6.1 Introduction and PEM Fuel Cell Principles
6.2 PEM Fuel Cell Model
6.2.1 Governing Equations
6.2.2 Control Volumes
6.2.3 Membrane Sub-model
6.2.4 Porous Media Sub-model
6.2.5 Liquid Water Dynamics in the Porous Media
6.2.6 Channel Sub-model
6.2.7 Thermal Sub-model
6.2.8 Electrochemical Sub-model

6.2.9 Partial Experimental Validation and Model Feasibility
6.2.10 Estimation Objectives and Model Reduction
6.3 Cathode Liquid Water Saturation Monitoring Through Nonlinear Observers
6.3.1 Observability Analysis
6.3.2 System Transformation
6.3.3 Observer 1: Low-Power Peaking-Free Dead-Zone Observer
6.3.4 Adding the Voltage Sensor
6.3.5 Observer 2: High-Gain Observer with Voltage Sensor and Low-Pass Internal-Model Filter
6.3.6 Observer 3: Direct Adaptive Observer
6.3.7 Numerical Simulation
6.3.8 Experimental Validation
References