This paper unveils the impact of non-linear induction motor drives on operation of transformer-less single-stage solar photovoltaic (SPV) grid tied inverter system. The system is controlled by an indirect type data-based maximum power point tracking (MPPT) technique. A fuzzy-logic controlled (FLC) dynamic voltage restorer (DVR) is operated coordinating two non-linear induction motor drives load: direct torque flux control (DTFC) and field-oriented control (FOC). Importantly, power quality (PQ) analysis for FOC induction motor drive is validated with DTFC induction motor drive. Results reveal mitigation of unbalanced voltage sag and voltage swell among the SPV converter, load and grid during transient conditions produced by fault. The effectiveness of FLC-DVR at FOC drive load is demonstrated over DTFC drive load and linear load for validation. It is worth mentioning that controlling action of FLC-DVR is implemented effectively at non-linear loads. As illustrated by IEEE-519/1547 standard, a reduction in total harmonic distortion (THD) and DC offset current is reported in grid voltage and current for accuracy. The proposed framework illustrates a comparative PQ study to justify satisfactory performance under varying environmental conditions.

Power quality monitoring for a solar PV grid controlled system at non-linear induction drives load

A Comparison of Instantaneous and Extension p-q Methods for Current Controlled Voltage Source Inverter in Microgrid

The energy demand due to the population growth and the exhaustible nature of fossil fuels led to the research and development in the grid integrated renewable energy system. The power electronic interfaces play a vital role for this integration. But the power electronic interfaces and the generally used non-linear loads like switched mode power supplies affect the power quality by making the non-sinusoidal grid current. In order to make the grid current sinusoidal, a controller is essential to govern the power electronic interface. In this work, a solar photovoltaic system is integrated to grid through inverter. Depending upon the weather conditions, the power generation in the solar photovoltaic system varies. This uncertainty is investigated as three cases in this work. They are nil generated power, insufficient generated power, and excess generated power to feed the load. A proportional-resonant controller is employed in this work to handle these cases and also to improve the quality of power. The simulation is performed in MATLAB/SIMULINK environment and the results are presented to validate the cases. 

Power Management in the Grid Integrated Solar Photovoltaic System

http://www.cell.com/article/S240584402305123X/pdf

A. Kavitha

Papers

Control of power in the grid integrated solar photovoltaic system using linear quadratic regulator