At the core of a more sustainable and robust power grid lies a crucial technological gap waiting to be bridged by scientists at the Department of Energy’s Oak Ridge National Laboratory (ORNL). Their mission is to create a harmonious balance within the grid, facilitating the integration of medium-voltage power electronics, a critical aspect for modernizing America’s electric grid.
The Gap in Power Electronics Voltage
Current power electronics operate at the polar ends of the voltage spectrum. Low voltage is used in everyday applications such as charging electric vehicles or managing solar panel outputs, while high-voltage applications are reserved for weightier tasks, including utility-scale renewable energy projects and power system linkages. However, the ‘medium-voltage’ area, which ranges between 1,500 and 50,000 volts, plays a pivotal role in larger-scale clean energy implementations and in the operation of heavier electric vehicles, like trains and certain aircraft.
By effectively addressing this ‘medium-voltage gap’, the U.S. can progress towards its clean energy objectives and enhance its power grid infrastructure, eliminating the need for additional transmission lines.
ORNL’s Dedication to Medium-Voltage Innovation
Prasad Kandula, leader of ORNL’s Grid Systems Hardware group, emphasizes the importance of developing medium-voltage technology that is both reliable and economically viable. As the guiding force behind DOE’s Medium Voltage Resource Integration Technology program (MERIT), ORNL, alongside its network of four national labs and five universities, is pioneering new devices designed to operate within this voltage spectrum efficiently.
Adopting medium-voltage power electronics not only promises cost benefits but also reduces the size and weight of systems. Kandula highlighted the expected efficiency gains and the ability to consolidate power in a compact space.
Grid Reliability and the Path to Clean Energy
Developing medium-voltage power electronics holds the key to upgrading electric grid capacity and providing economic development opportunities. These electronics facilitate the transition between alternating current (AC) and direct current (DC), an essential conversion given that renewable energy sources and electric vehicles primarily use DC.
Imagine the ability to transfer surplus electricity from one region to another to prevent energy shortages. Medium-voltage electronics can make this a reality, averting rolling blackouts and the need to rely on polluting backup generators. Additionally, converting segments of the grid from AC to DC increases the efficiency of long-distance power transmission without modifying existing infrastructure.
Kandula envisions a decentralized DC power ecosystem, starting with isolated microgrids that include solar power and battery storage, and potentially expanding to broader sections of the grid. A DC-centric approach minimizes power conversion equipment, thereby reducing energy loss and bolstering the efficiency and economy of clean energy sources.
ORNL’s Leadership in Medium-Voltage Research and Development
ORNL researchers are crafting a series of medium-voltage components that will shape the future of power electronics. Components like converter modules, advanced magnetics, and fault protection systems are part of a greater puzzle. MERIT’s strategy involves creating a modular approach, allowing for the combination of different building blocks to achieve desired voltage levels and explore a range of power applications, from recharging electric trucks to generating green hydrogen.
Leveraging the capabilities of ORNL’s Grid Research Integration and Development Center (GRID-C), the team simulates and tests different architectures, developing converters that can manage up to 13,000 volts.
MERIT’s strategic partnerships with utilities also help pinpoint the requirements for medium-voltage technology, enabling faster integration of lab innovations into the electric grid. This approach, coupled with ORNL’s extensive expertise, promises rapid advancements in the realm of medium-voltage power electronics.
With a coalition of renowned research partners, the MERIT project is committed to realizing the potential of medium-voltage power electronics, thereby transforming the U.S. power grid and taking a crucial step towards meeting the nation’s clean energy goals.
