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N. Yousefi

Publications and source records attributed to N. Yousefi.

2 recordsLinked to original sources

A storage expansion planning framework using reinforcement learning and simulation-based optimization

In the wake of the highly electrified future ahead of us, the role of energy storage is crucial wherever distributed generation is abundant, such as in microgrid settings. Given the variety of storage options that are becoming more and more economical, determining which type of storage technology to invest in, along with the appropriate timing and capacity becomes a critical research question. It is inevitable that these problems will continue to become increasingly relevant in the future and require strategic planning and holistic and modern frameworks in order to be solved. Reinforcement Learning algorithms have already proven to be successful in problems where sequential decision-making is inherent. In the operations planning area, these algorithms are already used but mostly in short-term problems with well-defined constraints. On the contrary, we expand and tailor these techniques to long-term planning by utilizing model-free algorithms combined with simulation-based models. A model and expansion plan have been developed to optimally determine microgrid designs as they evolve to dynamically react to changing conditions and to exploit energy storage capabilities. We show that it is possible to derive better engineering solutions that would point to the types of energy storage units which could be at the core of future microgrid applications. Another key finding is that the optimal storage capacity threshold for a system depends heavily on the price movements of the available storage units. By utilizing the proposed approaches, it is possible to model inherent problem uncertainties and optimize the whole streamline of sequential investment decision-making.

cs.LG

The impact of analytical outage modeling on expansion planning problems in the area of power systems

Expansion planning problems refer to the monetary and unit investment needed for energy production or storage. An inherent element in these problems is the element of stochasticity in various aspects, such as the generation output of the units, climate change or frequency and duration of grid outages. Especially for the latter one, outage modeling is crucial to be carefully considered when designing systems with distributed generation at their core, such as microgrids. In most studies so far, a single statistical distribution is used, such as a Poisson Process. However, by taking a closer look at the real outage data provided by the state of NY, it is observed that the outages do not seem to come from the same distribution. In some years, there is a huge spike in the average duration per outage and this is because of catastrophic events. Therefore, in this study we propose and test an alternative modeling for outage events. This alternative scheme will be based on the premise that outages can be broadly classified into two categories: regular and severe. Under this taxonomy, it can still be assumed that each type of events follows a Poisson Process but outages, in general, follow a Poisson Process which is truly a superposition of these two types. A reinforcement learning approach is used to solve the expansion planning problem and real location-specific data are used. The results verify our initial hypothesis and show that the optimization results are significantly affected by the outage modeling. To sum up, modeling accurately the grid outage events and measuring directly the reliability performance of an energy system during catastrophic failures could provide invaluable tools and insights that could therefore be used for the best possible preparation for this type of outages.

eess.SY