Grid-Tied Inverter for Smart Grids

A grid-tied inverter plays a crucial role in integrating renewable energy sources, such as solar or wind, with the existing power grid. It converts the DC power generated by these sources into AC power that can be fed back into the grid or used locally. This article aims to explore the performance and application of a grid-tied inverter in smart grids, focusing on a specific case study.

Literature Review: Several research studies have focused on inverter control techniques for grid-tied renewable and alternative power systems. Khan et al. (2020) conducted an in-depth analysis of grid-connected solar inverters, discussing different configurations, modulation methods, and control strategies. They categorized various multilevel inverter topologies and modulation methods and described different control reference frames for inverters. Other studies have emphasized the grid integration of sustainable energy technologies and the dynamic behavior of generation systems during grid faults and voltage sags.

System Overview: The investigated system in this study consists of a centralized grid-tied one-stage three-level diode clamped inverter connected to a hybrid PV-fuel cell (FC) system. The inverter operates under a synchronous PQ open-loop control scheme, aiming to achieve a current harmonic distortion of below 5%. The system includes a 150 kW/1400 V FC, a 150 kW/700 V PV array, a 265 kW/415 V inverter, and a passive LCL filter connecting the grid and the inverter.

Performance Evaluation: The performance of the grid-tied inverter system was evaluated using two operating scenarios. In scenario one, the hybrid PV-FC system produces power to feed a neighborhood load while also transferring the surplus to the grid. In scenario two, a neighborhood load of 365 kW is powered by the grid-tied PV-FC inverter, with additional power imported from the grid. The study demonstrated that the proposed system performed well, achieving a current harmonic distortion of about 0.33%.

Conclusion: In conclusion, the grid-tied inverter is a key component in smart grids, enabling the integration of renewable energy sources with the existing power grid. This article explored the performance and application of a grid-tied inverter in a specific case study. The study demonstrated the effectiveness of a centralized grid-tied one-stage three-level diode clamped inverter connected to a hybrid PV-FC system, achieving low current harmonic distortion. Further research and development in this field can lead to more efficient and sustainable energy systems for smart grids.