Compact storage-based resistance spot welding power supplies / von M.-Tech. Krishna Dora Venkata Mohana Murali. Erster Gutachter: Prof. Dr.-Ing. Joachim Böcker, Zweiter Gutachter: Prof. Dr.-Ing. Jürgen Petzoldt. Paderborn, 2016
Content
Abstract
Zusammenfassung
Acknowledgements
Contents
List of Figures
List of Tables
List of Acronyms
List of Symbols
1 Introduction and Thesis Overview
1.1 Background
1.2 Storage-based welding power supply - state of the art
1.3 Research objectives
1.4 Dissertation Outline
2 Specifications of the desired power supply
2.1 Introduction
2.2 Output characteristics
2.3 Other desirable characteristics
2.3.1 Audible noise
2.3.2 Galvanic isolation between storage element and output
2.3.3 Load duty ratio
2.3.4 Weight and volume
2.4 Specification sheet
3 Power Supply Topology
3.1 Modularity
3.2 Potentially suitable converter topologies
3.3 Interleaved buck converter
3.4 Interleaved buck controlled resonant converter
3.5 Interleaved phase-shifted full-bridge converter
3.6 Inter-cell transformer based buck converter
3.7 Interleaved tapped-inductor buck converter
3.8 Quantitative comparison of the qualified topologies
4 Energy Storage
4.1 Introduction
4.1.1 Criteria for selection of a storage technology
4.1.2 Storage technology pre-selection
4.1.3 Main factors influencing the storage system sizing
4.2 Evaluation of electrolytic capacitor based storage
4.2.1 Energy density
4.2.2 Equivalent circuit representation
4.2.3 Characteristics of equivalent series resistance
4.2.4 Power loss calculation
4.2.5 Designing for life time
4.2.6 Step-wise process for storage sizing
4.3 Evaluation of double layer capacitors based storage
4.3.1 Power density
4.3.2 Frequency characteristics
4.3.3 Equivalent circuit model
4.3.4 Step-wise process for storage sizing
4.4 Evaluation of flywheel storage system
4.4.1 Geometrical structure used for the analysis
4.4.2 Step-wise process for storage sizing
4.4.3 Step 1: Determining the motor dimensions and loss distribution
4.4.4 Step 2: Determining charging and discharging losses
4.4.5 Step 3: Determining the optimal FSS volume
4.4.6 Step 4: Obtaining the volume versus efficiency curves
5 Implementation Using Double Layer Capacitors and Interleaved Buck Converter
5.1 System overview
5.2 Obtaining the worst case plant transfer function
5.2.1 Effect of operating duty-cycle
5.2.2 Effect of load resistance
5.2.3 Effect of load inductance
5.2.4 Worst case plant transfer function
5.3 Influence of source resistance
5.4 Controller design
5.5 Experimental Setup
5.6 Results
6 Conclusions and Future Work
A Appendix A
B Appendix B
B.1 Flywheel basics
B.2 Motor type selection
B.3 Depth of discharge
B.4 Steel flywheel can be the best choice for SBRSWPS
B.5 Motor temperature under intermittent loading
Bibliography