In the rapidly evolving landscape of renewable energy, solar photovoltaic (PV) systems are increasingly becoming the go-to solution for sustainable power generation. However, the integration of these systems with the power grid presents unique challenges, particularly when it comes to reducing leakage current and managing reactive power. A groundbreaking study published in IEEE Access, the journal of the Institute of Electrical and Electronics Engineers, addresses these issues head-on. The research, led by Md Faruk Kibria from the Department of Electrical Engineering at the University of Malaya in Kuala Lumpur, Malaysia, introduces a novel hybrid topology for transformerless grid-tied inverters that promises to revolutionize the way we harness solar energy.
The study focuses on a critical aspect of grid-tied PV systems: the elimination of transformers to reduce overall system cost and weight. However, this elimination introduces a significant challenge—the absence of galvanic isolation between the AC grid and the PV system, leading to high leakage currents. “The leakage current with a high peak value flows across the system in the absence of galvanic isolation between an ac grid and PV,” Kibria explains. “This is a major hurdle in the widespread adoption of transformerless grid-tied inverters.”
To tackle this issue, Kibria and his team developed a hybrid topology that combines decoupling and mid-point clamping techniques. This innovative approach not only reduces the root mean square (RMS) and peak value of leakage current but also enables the system to provide both active and reactive power to the grid. “Our proposed topology can provide both active and reactive power to the grid,” Kibria states, highlighting the dual functionality of the system.
The researchers simulated the new topology in the Matlab/Simulink environment under both open-loop and closed-loop conditions. In open-loop conditions, the focus was on addressing the leakage current issue, while in closed-loop conditions, the system was tested for its ability to inject active power (P) and reactive power (Q) into the grid using model predictive control (MPC). The results were validated through experiments, demonstrating the effectiveness of the proposed topology.
The implications of this research are far-reaching for the energy sector. By reducing leakage current and enhancing reactive power capability, this hybrid topology paves the way for more efficient and reliable grid-tied PV systems. This could lead to significant cost savings and improved performance, making solar energy an even more attractive option for both residential and commercial applications.
The study, published in IEEE Access, which translates to “IEEE Open Access,” underscores the importance of innovative solutions in the field of renewable energy. As the demand for clean and sustainable power continues to grow, advancements like this will play a crucial role in shaping the future of the energy sector. The research by Kibria and his team at the University of Malaya represents a significant step forward in this direction, offering a glimpse into the potential of transformerless grid-tied inverters and their impact on the broader energy landscape.
