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Abstract
Solar Panel Companion Inverters (SPCIs) have been proposed as H-bridge inverters embedded with a PV module. These inverters employ a unique methodology that converts the conventional DC voltage output of a solar panel to switched quasi-square wave voltages with variable pulse width. These SPCIs are connected in series to produce an aggregated superior quality multilevel waveform that can be directly interfaced with the AC grid. This alternative approach offers advantages of micro-inverters in realizing panel-level maximum power point transfer and realization of system-level cost benefits of a central inverter. In this dissertation, dynamic analysis and closed loop controller design of SPCIs is presented. Maximum Power Point Tracking (MPPT) for SPCIs is proposed to demonstrate the panel level maximum power extraction from the solar panels. Simulations are performed using MATLAB Simulink, to demonstrate efficacy of the MPPT algorithm. Reactive power support of SPCIs while maintaining MPPT is explored. Panel level optimization is investigated by performing analysis for synthesizing AC output voltage across each SPCI. Using the analysis, a modified sort and stack algorithm is presented to implement Sorted Stair Case Modulation and Sorted Pulse Width Modulation strategies. A laboratory prototype was constructed to demonstrate the principle of sort and stack algorithm, closed loop current control and grid tie operation. Also, reactive power support while maintaining MPPT is experimentally demonstrated.