About The Series: ESIG members play many different kinds of roles in energy systems integration and have followed unique paths to their current positions. This “Career Perspectives” blog series taps into the diversity of experiences and perspectives of ESIG members through interviews that explore their educational backgrounds, career trajectories, key decision points, and mentorship experiences, as well as how they see today’s workforce needs in energy systems integration and what advice they would give students considering a career in this area.
Deepak Ramasubramanian, EPRI
What did you study when pursuing your undergraduate and graduate degrees, and what were your original career goals?
I did my undergraduate and master’s degrees in India, with an undergraduate degree in electrical and electronics engineering and a master’s degree in electrical engineering with a specialization in power systems. Looking back, what started me on this trajectory was an undergraduate semester project in which another student and I built a small electrical motor from scratch from things we found lying around. Until then, for me the concepts of electromagnetism and its association with Newton’s laws of motion were only in textbooks. That experience of putting these concepts into motion, seeing things moving, and appreciating how electrical energy can translate through “thin air” and bring about mechanical energy that ultimately produces tangible results was what brought me into the field of power systems. The way in which the physical and mathematics aspects merged appealed to me, especially when studying electrical machines. Distinct physical properties play a role, but you can also envision them by looking at the mathematical equations; the two fit together.
My focus on renewable energy and energy systems integration emerged while completing my master’s degree between 2011 and 2013. This was a time in India when microgrids were beginning to attract more attention, as were uninterrupted power supplies, which allowed homes to ride through the hot summers — one of India’s major blackouts occurred during the summer peak in 2012. The costs of solar were also starting to decline, and solar was no longer considered a fancy item. These all put me on the path toward renewable energy and energy systems integration.
What was the focus of your first major research project in power systems engineering?
I did my PhD at Arizona State University working with Professor Vijay Vittal, who had been an advisor to one of the professors in my master’s program in India. My research was funded by the Power Systems Engineering Resource Center, a group of industries and utilities that fund academic research. I had the opportunity to interact with ESIG (then UVIG (the Utility Variable-Generation Integration Group) industry members who served as advisors on my dissertation and were also active participants in this organization. The ESIG spring and fall technical workshops offered an ideal setting for students to meet prospective employers. In addition, working with my advisor at Arizona State and Dr. John Undrill, who were very well known in the industry, exposed me to an industry perspective in addition to my academic perspective.
My PhD research looked at how you operate a large power system when you have a lot of inverter-based resources. More specifically, I studied the impacts of converter-interface generation and load on grid performance. Where we were going toward was — with the massive decarbonization happening in California and starting to happen in Arizona — if you have to operate the entire western part of the United States, one synchronous power network, only on renewable energy, can you be stable and secure and still supply a reliable source of power across the entire network?
My dissertation investigated how to simulate and how to mathematically model these devices. If you have growth of solar and wind, how do you represent them in your studies, how do you parameterize them, and how do you ensure they are stable in a dynamic sense? If you have a fault, a generation trip event, how would the system react?
The other aspect of my dissertation looked at it from the perspective of consumer or industrial loads. When you have a lot of smart devices, you no longer just hook up a motor to the electrical supply. You always have a smart device between the load and the electric network. While this increases the energy efficiency of the device, it also isolates the natural characteristics of the device from the network. Thus, the network now sees only a characteristic that has been programmed and is not natural. Understanding how they impact the entire network was one aspect of my dissertation.
My research also looked at the generation side. When the natural behavior of generation is changing from rotating machine–interfaced to inverter-interfaced (like solar, wind, and storage), how do you study such a system? And once you can study it, what are you supposed to be looking for? Is there a different stability profile, or is there a different way in which electricity can be supplied reliably and optimally? Would there be new kinds of operating modes that would be applicable, such as moving away from frequency control and only focusing on voltage control? Would the traditional centralized top-down method of delivery of power change to become a decentralized delivery?
What job did you move into after you completed your PhD?
I finished my PhD in 2017 and joined the Electric Power Research Institute (EPRI). In my current position there I play a few different roles. The first is technical. As a collaborative resource entity with multiple funders, EPRI’s work gets split up into numerous technical projects and programs. I lead some, where I’m actually doing the technical work, and manage others, overseeing their design and tracking their progress. In one project, I work on grid-forming inverters, looking at how to design and operate them. For example, I set up experimental studies to analyze whether a grid-forming inverters will be useful or harmful for the grid in given situations.
I also interact with our utility members, serving as a technical point of contact to answer questions, help them understand what they’re seeing in their studies, or help design future studies. Much of the research I am involved with at EPRI is focused on the development of simulation models and defining how to accurately parameterize such models. How do you mathematically represent a specific solar plant in your simulation software, which model do you use, what are the parameters to set? For example, a utility might have received a model of a solar plant from the owner for the purpose of studying the potential effect of the generator on the system, but something came up in the simulation results that doesn’t make intuitive sense or is causing an issue. The utility might reach out to EPRI and ask, have you seen this before in your research? How can we mitigate this?
Additionally, I represent EPRI on various task forces and working groups such as those of the Institute of Electrical and Electronics Engineers (IEEE), ESIG, the North American Electric Reliability Corporation (NERC), and others, where people from different aspects of industry come together to solve a problem or try to understand how problems should be addressed going forward, for example, by creating a technical reference document. I present EPRI’s research, participate in discussion, and see where we can contribute for the public benefit, which is what EPRI is all about.
What guidance would you offer a young person interested in a career in renewable energy and energy systems integration?
Power systems engineering is increasingly interdisciplinary. Ten or 15 years ago, power systems might have been 80 percent about electrical networks and 20 percent other topics to bring them all together, but our understanding of the network now and our way of operating and controlling it requires massive interdisciplinary research. We now have operations research and optimization, statistical analysis, machine learning, communications protocols, and control systems theory all rolled together. An example is the mechanics of how to design controllers for inverter-based resources so that they recognize when a grid fault, for instance, occurs on the network and react in a favorable manner (the nature of their reaction can depend on their operating point, network characteristics, weather forecasts, etc.) to help prevent the power system from collapsing. It is important to have as much of a background in interdisciplinary fields as possible, for someone who wants to dip their toe in the pond.