Firstly you may be asking, What exactly is a Micro grid and why are they important? Microgrids are just what the name implies, they are localized subsystems of the larger electrical grid that have the ability operate independently. Microgrids are typically built to power critical and uninterruptible loads in urban areas with an area of approx 1 mile x 1.5 mile, or, about 500 football fields.
Microgrids are important for a number of reasons. From community based initiatives such as resilience, grid efficiency, and the managing of increased deployment of Distributed Energy Resources (DER) to larger scope projects like deferring transmission and distribution (T&D) upgrades, and exploration of non wire alternatives to new generation; microgrids have a wide area of application.
Microgrids are not a new concept. Their use in the petroleum industry (where they are referred to as power management systems) is well documented, and has been the main source of technological innovation in the past few decades. With the declining costs of solar PV and energy storage systems, public and private entities continue to innovate (at a faster pace than ever) in the face of climate change. Our industry should advocate for DER heavy Microgrids so that we may see continued interest from our policy makers in adopting this technology on the electrical utility grid. We at CivicSolar have discussed microgrid regulatory policy in the past and will continue to be active in the space -as the adoption of IEEE standards is recognized as the critical first step.
The purpose of this post is to highlight the role of simulation based control systems and to show how they will drive innovation and increased adoption of Microgrids; specifically those deploying DER’s.
Researchers at the MIT Lincoln Laboratory have developed what they call a Hardware-In-the-Loop Laboratory Testbed and Open Platform (HILLTOP). HILLTOP is a collaborative effort that encourages users to test combinations of control/inverter hardware and specific grid events against a software that is used to generate high fidelity real time grid simulation environments. These experiments allow for the utility to completely evaluate new technologies to high technical standards in a cost effective and timely manner.
It may be helpful to imagine this as a similar problem solving approach taken by that of mapmakers and harbor pilots of the 19th & 20th centuries. Before you could bring a new ship into a new harbor it was critical to test all the variables. At first, measuring depth was good enough but as ships became larger and faster we eventually needed to build models. At a 1:25 scale engineers could effectively test the effects of shallow waters, currents, bank effects, waves, and vessel interactions all with high accuracy and relatively low cost. HILLTOP represents a next generation Utility distribution testing platform which is completely digital.
The North American electrical power grid is famously referred to as the largest and most complicated machine ever built by man. At a high level view this machine can be thought of as a single enormous circuit. It is currently designed around fossil fuel driven high inertia prime mover generators all with minimal controls in place. We are trying to shift to a system characterized by many distributed generators with dynamic digital grid interactive controls. Because there are strict anti-islanding protocols in place under the IEEE 1547 standard, PV energy is typically not prioritized in a microgrid. HILLTOP could provide special benefit to Solar PV users by allowing testing that would support advanced grid support features when islanded and thus updates to the standard. Such a shift would increase the complexity of the grid by an order of magnitude or more. Statistically speaking driving the degrees of freedom up into the thousands. Regardless, in order to shift to a more sustainable from of power generation while maintaining high levels of reliability certain controls must be put in place. I believe initiatives such as HILLTOP provide the tools necessary to make our way towards this goal.
In addition to having a rich nautical history, Boston is an example of a city that has shown excellent vision for planning ahead. Having recently completed the Boston Community Energy Study the city is poised to be on the forefront of local energy generation, district energy and microgrids. Project developers and vendors who wish to contribute to the platform’s repository of results are encouraged to download the source code and documentation required to run such tests on the PowerSystemsHIL github page.
