Date(s) - 6 Dec 2017
1:10 PM - 2:00 PM
2222 Coover Hall
Speaker: Ashraf Radaideh, ECpE Graduate Student
Adviser: Venkataramana Ajjarapu
Title: Sequential Set-Point Control of Thermostatic Loads Using Extended Markov Chain Abstraction to Improve Future Renewable Energy Integration
Abstract: Additional flexible resources are required to achieve resilience and sustainable power systems. Challenges emerged due to the increasing amounts of renewable generation penetrations at both the bulk power system and the distribution sides. Among the possible solutions, demand side resources can make the system more elastic and help in integrating the future renewable energy plans. In this work, a novel demand side control on the Thermostatically Controlled Loads (TCLs) is introduced to provide grid support in various ancillary services. The Markov chain abstraction method is used to aggregate the TCLs and describe their collective dynamics at fixed temperature set-point. Markov chains are identified using statistical learning techniques of hidden Markov chain analysis. The resulting models are used to develop an Extended Markov Model (EMM) which describes devices transition and the aggregated power dynamics when a new set-point is instructed. The accuracy of the EMM model is affected by devices heterogeneity. Therefore, K-mean clustering is proposed to divide the devices into multiple clusters based on the power ratings and the cycling characteristics. The results have shown that the clustering approach highly improves the EMM performance and minimize the heterogeneity errors. Set-point adjustments cause the aggregated power to experience abrupt changes and oscillations before it converges to the new steady state value. Such power profiles may cause serious stability issues. Therefore, Model Predictive Control (MPC) with direct ON/OFF switching capability is proposed to apply the set-point control sequentially and prevent any possible oscillations. In contrast to the methods introduced in the literature, the proposed modeling and control approaches provide the required ancillary services while maintaining both the customers comfort and the devices integrity.