Study of Controlling Methods of Inverters used in the Grid in conjunction with renewable energy sources

摘要

Power converter devices interfaces the grid with RESs which injects the harmonic current in the system. Hence, this paper presents different controlling schemes for inverters used in the grid. Phase-shifting control of single-phase inverter has been shown in this paper which provides power control injecting to the grid. $3-arphi$ inverter control involves dq control, $lphaeta$ control, and abc control. The use of voltage (reactive) and frequency (active) control scheme provides mitigation of voltage harmonics. Various scheme for controlling Multi-Functional Grid-connected inverter involves double loop dq control on the basis of discrete Fast Fourier Transform and Phase Lock Loop method is used which helps in coordination of active (frequency) and reactive (voltage) power control. Various controlling method for Z-source inverter has been presented which helps in improvement of the quality of power of the distribution system.