Search

This study highlights the critical role of maintaining high power quality in autonomous grids, particularly in complex systems with significant non-linear loads, such as shipboard power systems. Power quality issues such as voltage harmonic distortion and imbalance can lead to serious malfunctions and even accidents. This paper proposes an advanced predictive control algorithm with feedback from the supply current developed for a shunt active power filter. The presented control algorithm is characterized by high effectiveness in compensating supply current harmonics, imbalance, and reactive power, thereby improving power quality. This high performance in executing compensation tasks has been confirmed through experimental tests conducted in an autonomous grid powered by a diesel generator. The research results also include the system's adaptability under varying load conditions, the impact of delays, and the converter's non-linearities on the operation of the active power filter. [ABSTRACT FROM AUTHOR]

Islanded grids operate isolated from the main grid and they allow the use of ac with a different frequency from the main grid. In this paper, it is proposed to use more than one frequency at the same time in such autonomous systems. The grid voltage amplitude at the fundamental frequency can be increased while the voltage peak is constant by adding odd harmonics to the voltage waveform. The grid currents and the power converter currents are decreased for the same power level, which leads to reduced losses in the system. The currents can be minimized if waveform shaping is additionally applied to the current waveforms. The approach also offers the possibility of mitigating the influence of low power factor in single-phase systems. This paper presents the impact of multifrequency power transfer on single-phase converters and grid components such as power cables and protection, and verifies the results with analysis, simulations, and experiments. [ABSTRACT FROM AUTHOR]