The recent R&D 100 awards have proven yet again that innovation is alive and well at the Department of Energy’s national laboratories. The winners included two important projects at Sandia National Laboratories that were supported by the Office of Electricity Delivery and Energy Reliability’s (OE) Advanced Grid R&D Division: the Microgrid Design Toolkit (MDT), and the Control System for Active Damping of Inter-Area Oscillations. Both projects have major implications for improving the resilience and reliability of the nation’s power grid – from design to operation. Allow me to explain.
Microgrids are localized energy grids that provide flexibility through their ability to operate independently from the bulk power grid. Well-designed microgrids are key components of security and resilience in the electrical infrastructure, as they provide local control and increased access to renewable resources. Because microgrids can provide power during emergencies and help with orderly recovery from energy emergencies, more and more people have become interested in microgrids. The Microgrid Design Toolkit (MDT) is a decision support software tool that is intended to be used in the preliminary design phase to aid designers in creating optimal microgrids. Its ability to perform topology optimization and energy resource selection and sizing; account for both grid connected and islanded performance, power and component reliability in islanded mode, and dozens of metrics when performing the trade space search; and present a user with an entire trade space of information from which to draw conclusions make it a significant advancement over anything available to designers today. Already, the MDT technology has been used to design three microgrids at military bases that have subsequently been built and are currently operating as well as a microgrid design for Hoboken, NJ following Hurricane Sandy.
When it comes to operating the grid, inter-area oscillations can be a problem when the demand for power is high. As more power is transmitted, the amplitudes of the oscillations build and can become disruptive to the point of causing power outages. Until now, the only safe and effective way to prevent disruptive oscillations has been to reduce the amount of power sent through a transmission line which is not very economical. The Control System for Active Damping of Inter-Area Oscillations uses measurement data, acquired in real-time, from phasor measurement units, recently installed throughout the western North American Power System. This measurement data serves as a feedback signal to tell the controller as to how much power to add or subtract to the power flow on the high voltage (500 kV) direct current (HVDC) transmission line. The controller then modulates the power flow. This carefully controlled “injection” of power is the action that smooths out oscillations in the grid, allowing utilities to push more electricity through transmission lines, leading to lower costs for utilities and consumers and greater stability for the grid.
Congratulations, Sandia National Laboratories, on receiving these prestigious awards!