In the ever-evolving landscape of energy distribution, a groundbreaking study published in the IEEE Open Journal of the Industrial Electronics Society is set to redefine how we manage power quality and grid hosting capacity in low-voltage grids. Led by Joao Marcus S. Callegari from the Graduate Program in Electrical Engineering at Universidade Federal de Minas Gerais in Belo Horizonte, Brazil, this research introduces a novel approach to controlling power in grid-connected AC microgrids (MGs), promising significant improvements for both utilities and consumers.
The increasing integration of nonlinear loads (NLLs) and distributed energy resources (DERs) into our power grids has presented a formidable challenge. These elements can degrade power quality and strain grid hosting capacity, leading to inefficiencies and potential disruptions. Callegari’s innovative solution tackles these issues head-on with a centralized multimode selective power control strategy that doesn’t require prior knowledge of microgrid parameters.
At the heart of this strategy lies a generalized power-based control algorithm, which operates in two nonsimultaneous modes: centralized and decentralized. In the centralized mode, the algorithm enables selective harmonic and distortion power dispatch, enhancing disturbance rejection and accuracy in power tracking at the point of common coupling (PCC). This is a game-changer, as it allows for the first-ever application of feedback, feedforward, and disturbance decoupling actions to distortion and harmonic power in microgrids.
“Our approach ensures that we can maintain high power quality even as we integrate more complex loads and resources into the grid,” Callegari explains. “This is crucial for both the reliability of the grid and the satisfaction of end-users.”
In the decentralized mode, the strategy achieves harmonic current compensation without the need for communication links, significantly reducing data traffic. This mode also enables resistive load synthesis at the PCC to dampen upstream grid resonances, sinusoidal current synthesis for improved current quality, and harmonic current compensation based on voltage measurements to enhance voltage quality at internal nodes.
The implications for the energy sector are vast. Improved power quality means reduced equipment wear and tear, lower maintenance costs, and enhanced reliability for both utilities and consumers. Moreover, the ability to manage harmonic and distortion power more effectively can lead to better compliance with standards, potentially opening up new market opportunities for energy providers.
Callegari’s research, published in the IEEE Open Journal of the Industrial Electronics Society (translated to English as IEEE Open Journal of the Industrial Electronics Society), has already shown promising results in simulations and experimental setups. In decentralized mode, the total harmonic distortion (THD) of PCC voltage improved from 10.65% to 1.09% under weak grids. In centralized mode, with sinusoidal current synthesis up to the 11th harmonic, PCC current THD was reduced from 61.18% to 3.42% under stiff grids.
As we look to the future, this research could pave the way for more intelligent and adaptive microgrid management systems. The ability to selectively control power in real-time, without prior knowledge of grid parameters, could revolutionize how we approach energy distribution and consumption. It’s a significant step forward in our journey towards smarter, more resilient energy grids.