This map of the United States shows existing and potential high-voltage DC transmission lines in states with the highest solar potential, as well as candidate sites for multiport autonomous reconfigurable solar power plants. Credit: ORNL, US Department of Energy.
A team led by the Department of Energy’s Oak Ridge National Laboratory has developed a utility-scale design and control system for a hybrid solar power plant that can operate on both direct current and alternating current. It offers greater flexibility, security and reliability than similar power plant operations. today. A hybrid plant includes not only a solar array, but also a battery to store the energy obtained from the sun.
The Multiport Autonomous Reconfigurable Solar Power Station (MARS) project integrates a complete suite of power electronics, electrical architecture, and cybersecurity software into one package to simplify deployment. ORNL and industry partners are working towards the first field demonstrations, or scaled-down versions of the full design, of MARS components that support grid stability.
Most of the US power grid uses alternating current, or AC, which constantly switches the direction of electron flow. In contrast, solar arrays and batteries use unidirectional direct current or DC. The American power transmission system contains fewer high voltage DC lines and is more efficient at delivering large amounts of power over long distances or remote locations. Special power electronics are required to convert current between DC and AC.
Researchers at ORNL were faced with the challenge of finding a cost-effective way to integrate large-scale hybrid renewable energy plants capable of supplying power to both AC and DC high voltage lines. This could make it easier and more reliable to transfer renewable energy to remote cities with high energy demand, potentially supporting decarbonization goals.
Over the course of three years, the ORNL team, led by Suman Debnath, has developed and enhanced a suite of power electronics, circuit architectures, control systems, and cyber intrusion detection algorithms that work together as an integrated system. MARS can be easily scaled to different power levels and integrated with new solar and battery systems.
Southern California Edison is a partner in this research.
Md Arifujjaman, Senior Engineer, Grid Innovations at SCE, said: “MARS is very helpful in terms of good algorithms for tracking cybersecurity issues and technologies that can be used on the DC side.” DC technology also holds promise for reducing DC voltages in electric vehicle charging stations. I added that it is.
This project included innovations in inverters of the type that could maintain grid stability and jump-start the grid after failures. This “grid-forming” technology could help prevent cascading blackouts during the wildfires that plague California, he said.
In addition, MARS’ “one-box” package of software, power electronics and architecture is attractive to utilities as it reduces both the cost and time delays arising from coordinating hardware development and installation.
The project team created a case simulation based on two specific sites in California. Simulations in hardware reveal significant advantages of ORNL’s designed power electronics framework for power grids. Up to 50% less power loss, 16% better AC voltage frequency regulation, and 100% detection of cyber intrusions such as malicious sensors. data.
The system was also more resilient as it could reconfigure autonomously based on available energy. For example, even at night when the solar panels were not generating electricity, MARS could keep the AC and DC transmission systems connected and use battery power to supplement its operation.