Researchers from the University of New South Wales in Sydney, Australia, have developed a novel energy router architecture that could significantly improve the integration and management of renewable energy sources in hybrid AC-DC grids. The team, led by Ehsan Asadi, has proposed a system that enables precise control of voltages and power flows in both AC and DC grids, addressing some of the key challenges in modernizing our energy infrastructure.
The researchers recognize that the share of power from renewable sources, loads, and storage that requires electronic conversion is continuously growing in low- and medium-voltage grids. These sources and loads typically convert grid AC to DC, for example, for a DC link. A DC grid could eliminate the hardware and losses of these conversion stages. However, extended DC grids lack the stabilizing nature of AC impedances, making the voltage more fragile and power flows potentially requiring active control. The proposed partial-power energy router architecture interfaces multiple AC and DC lines, enabling precise control of voltages and both active as well as reactive power flows.
The system uses modular low-voltage high-current series modules supplied through dual active bridges. These modules only need to process a small share of the voltage to control large power flows. This topology reduces component size, cost, energy losses, and improves reliability more than three times compared to conventional technology. The optional integration of battery energy storage can eliminate the need for the sum of the power flows of all inputs to be zero at all times. Through dynamic voltage injection relative to the line voltage, the modules effectively balance feeder currents, regulate reactive power, and improve the power factor in AC grids.
The researchers validated the proposed energy router’s performance under diverse operating conditions using real-time hardware-in-the-loop and prototype measurements. Experimental results confirm the series module’s functionality in both AC and DC grids as an effective solution for controlling extended grids, including power sharing, voltage, and power quality.
This research, published in the IEEE Transactions on Power Electronics, presents a promising solution for the energy sector, particularly for integrating renewable energy sources and managing hybrid AC-DC grids more efficiently and reliably. The proposed energy router architecture could play a significant role in modernizing our energy infrastructure and facilitating the transition to a more sustainable and resilient energy system.
This article is based on research available at arXiv.