| Abstract [eng] |
World pollution remains one of the most important problems in the world so more and more attention is focused on renewable energy sources which generated voltage often differs from the public grid or electronics used standard voltage. Voltage source inverters are used to match these voltages. Negative parasitic harmonics are made while changing direct voltage to alternating because of the inverter technical characteristics. Low pass filters are used to filter these parasitic harmonics and ensure voltage quality requirements. If this condition is ensured, to reach maximum energy efficiency, filter parameters have to be kept to a minimum while voltage maintains quality requirements. Microgrid inverters, their schemes, techniques and factors which affects the harmonic distortion are analyzed in this paper. Total harmonic distortion selected as the main evaluation factor. Full bridge inverter controlled by sinusoidal pulse width modulation was selected for research which is widely used in microgrids. Inverter model was made with MATLAB Simulink program. Modelling have shown that total harmonic distortion value depends on various load levels, filter and pulse width modulation parameters. Inverter control scheme and characteristics were presented which allows to ensure harmonic distortion required level while maintaining the highest energy efficiency. |
