الفهرس 
Dissertation AbstractsOnly 14 pages are availabe for public view
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Abstract
This thesis presents grid impedance estimation method using the output switching current ripple of a Space Vector Pulse Width Modulation (SVPWM) based grid connected converter. The proposed impedance estimation technique is capable of identifying the total inductance seen by the converter. However, it is unable to identify the resistance of the grid impedance. The estimated impedance is used for islanding detection and online current controller parameter tuning. Theoretical analysis and MATLAB simulation results are presented to verify the proposed method and its effectiveness is validated using experimental testing. It also proposes a method for Integrated Active Damping (IAD) of resonance in LCL-filtered converters connected to weak grids. To extend the system stability range and provide sufficient resonance damping, a participatory design for the grid current controller and the proposed IAD method are presented. The effectiveness of the proposed active damping method and improved stability are firstly demonstrated through time domain simulation and finally experimental investigation obtained in the laboratory. In addition, the effectiveness of the proposed IAD technique under multi-resonance peaks of multiple parallel grid connected converters is presented. Frequency domain analysis for multiple parallel converters without and with the proposed IAD are investigated. Time domain simulation and experimental results for two parallel grid connected converter at different operating scenarios are provided.