SEMINAR: Supporting the power grid with flexible loads and storage
Power grids are currently undergoing large changes due to increasing shares of fluctuating Renewable Energy Sources (RES). The variability of RES brings new challenges to the traditional power system operation because the generation and demand of electric power must be balanced at all times.
This talk discusses control approaches that utilize the flexibility of loads and battery storage to compensate for RES variability. Specifically, the control schemes involve thermal loads such as Heating, Ventilation, and Air Conditioning (HVAC) systems of commercial buildings, as well as smaller Thermostatically Controlled Loads (TCLs), for example, electric water heaters and refrigerators. Due to thermal storage, the electric power consumption of such loads is flexible and can be shifted in time without compromising occupant comfort.
Most of the talk focuses on provision of primary frequency control from large TCL aggregations, secondary frequency control from smaller aggregations of HVAC systems, as well as their combined effect on power system frequency dynamics. In addition, we discuss voltage control options in distribution grids by means of TCL control and optimal battery sizing and placement. Finally, we present an approach to maximize the amount of rooftop photovoltaic energy that is consumed locally within the building premises. We elaborate on control designs that employ methods from hierarchical control, model predictive control, robust and stochastic optimization, and present results from simulation studies, demonstration experiments and field operation.
PhD in Electrical Engineering and Information Technology, Elektrizitätswerke des Kantons Zürich (EKZ), Smart Grid Laboratory,
Evangelos Vrettos is a Home Energy Systems Engineer at the Smart Grid Laboratory of the Swiss electric utility EKZ (Elektrizitätswerke des Kantons Zürich). He received the Dipl.-Ing degree in Electrical and Computer Engineering from the National Technical University of Athens (NTUA), Greece, in 2010. After his graduation, he worked as a research assistant at the Electric Machines and Power Electronics Laboratory of NTUA. In 2011, he joined the Power Systems Laboratory of ETH Zurich, where he obtained the Ph.D. degree in Electrical Engineering and Information Technology in 2016 and continued as a postdoctoral researcher before joining EKZ. In 2015, he was visiting researcher for five months at the University of California, Berkeley (Energy and Resources Group), and the Lawrence Berkeley National Laboratory (Grid Integration Group). Evangelos Vrettos is interested in methods from control theory and optimization that facilitate integration of renewable energy sources in the power grid by engaging flexible demand-side and storage resources.