Chapter 1 Introduction
1.1Background and significance of study
1.2Objective of the thesis and main contributions
1.3Review of related research
1.4Outlines of the thesis
Chapter 2 Fundamentals of Grid-Connected PV Systems and Their Controls
2.1 Introduction
2.2Structure and topologies
2.2.1 Connection topologies of PV systems
2.2.2 Power conditioning unit
2.3Description of grid-connected PV system and component modeling
2.3.1 Description of PV system structure
2.3.2Modelling of PV system components
2.4Mathematical model of a grid-connected PV system in dq frame
2.4.1Park’s transformation (or dq transformation)
2.4.2Mathematical model of a PV system in dq frame
2.4.3 Grid synchronization
2.5PV system control under normal operation
2.5.1DC-DC converter control and MPPT
2.5.2Three-layer control scheme
2.6Simulation results
2.7 Summary
Chapter 3 Control of PV Systems under Balanced Grid Faults
3.1 Introduction
3.2Standards and requirements for PV grid integration
3.2.1 Grid codes
3.2.2 Stationary grid support
3.2.3 Voltage support during grid disturbance
3.3Control strategies under balanced gridfaults
3.3.1 Boost DC‐DC converter control
3.3.2Two-layer inverter controlscheme
3.4Simulation results
3.5 Summary
Chapter 4 Control of PV Systems under Unbalanced Grid Faults
4.1 Introduction
4.2Control strategy under unbalanced grid faults
4.2.1 Framework of the proposed control strategy
4.2.2 Fault detection and grid voltage synchronization
4.2.3 Power references calculation
4.2.4Power reduction strategy for DC-link voltage control
4.2.5 Proposed current reference generators
4.3 Inverter controller implementations
4.3.1Inner control loop:current controller design
4.3.2Outer control loops
4.3.3Inverter current limitation
4.4 Simulation results
4.5 Summary
Chapter 5 Impactsof PV Integration on Voltage Stability of Weak Grids
5.1 Introduction
5.2 Definition and measure of grid strength
5.2.1 Definition of grid strength
5.2.2Measurement of grid strength
5.3Overview of voltage stability analysis
5.3.1Definition of voltage stability
5.3.2 Classification of voltage stability
5.4Test system and its modeling
5.4.1 Test system
5.4.2Simplified PV system model
5.4.3Load modeling
5.5Impacts of FRT strategies of PV systems on voltage stability of weak grids
5.5.1 Existing FRT control strategies
5.5.2Proposed FRT control strategy
5.5.3Case studies for analysis of voltage stability
5.6 Summary
Conclusions and Future Work
Conclusions
Future work
参考文献
Publication During the Doctoral Study
声明
致谢
Cirriculum Vitae (CV)
哈尔滨工业大学;
