Data-Driven Methods for Virtual Energy Storage System Optimisation Under Uncertainties

This thesis focuses on development of efficient data-driven model-based and model- free solution methodologies as a key feature to address the challenges of building energy management systems (BEMSs). As the major consumers of global elec- tricity, BEMSs have recently attracted significant research interest. Nevertheless, traditional methods suffer from inefficient control strategy with regard to building local and central controllers. Moreover, they rely on assumption of a known model of uncertainties and system characteristics which could be far from reality, and impair the system optimality and security, and consumer’s comfort. Modern technologies have provided a data-rich environment that the traditional methods fail to fully exploit or to adapt. Thus, data-driven methods by use of advanced mathematical- and deep reinforcement learning (DRL)-based methods are required. While virtual energy storage systems have become a viable solution for provision of frequency reg- ulation services (FRS), the optimal capacity of a building for provision of FRS is not modelled. Lastly, available real-time DRL-based methods suffer from computational inefficiency for hyper-parameter tuning, and security issues for constraint violations. In chapter 2, a novel hierarchically coordinated control methodology is proposed which fully addresses the mutual impact between local and central controllers. In chapter 3, a novel model for optimal capacity of building for provision of FRS is developed, in which safe operation in pre- and post-FRS is considered. In chapter 2 and 3, data-driven distributionally robust optimisation method based on Wasserstein metric and a finite set of data is developed. The proposed data-driven methods tackle various uncertainties by guaranteeing that the out-of-sample performance complies with a pre-defined conservatism level. In chapter 4, an advanced DRL methodology is proposed for day-ahead and real-time BEMSs. Specifically, a multi- agent deep constrained Q-learning algorithm is developed, where safe action spaces of various agents are directly addressed in the Q-update process. The proposed method satisfies the agents’ individual and system-wide constraints, and improves hyper-parameter tuning by avoiding reward shaping technique. In the comprehensive numerical analysis of all the proposed methods, comparison with various traditional methods is carried out, demonstrating superiority of the proposed methods in terms of computational efficiency and optimal performance

Foundations of Infrastructure CPS

Infrastructures have been around as long as urban centers, supporting a society’s needs for its planning, operation, and safety. As we move deeper into the 21st century, these infrastructures are becoming smart – they monitor themselves, communicate, and most importantly self-govern, which we denote as Infrastructure CPS. Cyber-physical systems are now becoming increasingly prevalent and possibly even mainstream. With the basics of CPS in place, such as stability, robustness, and reliability properties at a systems level, and hybrid, switched, and eventtriggered properties at a network level, we believe that the time is right to go to the next step, Infrastructure CPS, which forms the focus of the proposed tutorial. We discuss three different foundations, (i) Human Empowerment, (ii) Transactive Control, and (iii) Resilience. This will be followed by two examples, one on the nexus between power and communication infrastructure, and the other between natural gas and electricity, both of which have been investigated extensively of late, and are emerging to be apt illustrations of Infrastructure CPS

Energy Optimization and Coordination Frameworks for Smart Homes Considering Incentives From Discomfort and Market Analysis

The electricity demand is increasing with the growing use of electricity-based appliances in today’s world. The residential sector’s electricity consumption share is also increasing. Demand response (DR) is a typical way to schedule consumers’ energy consumption and help utility to reduce the peak load demand. Residential demand management can contribute to reduce peak electric demand, decrease electricity costs, and maintain grid reliability. Though the demand management has benefits to the utility and the consumers, controlling the consumers electricity consumption provides inconvenience to the consumers. The challenge here is to properly address the customers’ inconvenience to encourage them to participate and meanwhile satisfy the required demand reduction efficiently. In this work, new incentive-based demand management schemes for residential houses are designed and implemented. This work investigates two separate DR frameworks designed with different demand reduction coordination strategies. The first framework design constitutes a utility, several aggregators, and residential houses participating in DR program. Demand response potential (DRP), an indicator of whether an appliance can contribute to the DR, guides the strategic allocation of the demand limit to the aggregators. Each aggregator aggregates the DRP of all the controllable appliances under it and sends to the utility. The utility allocates different demand limits to the aggregators based on their respective DRP ratios. Participating residential customers are benefited with financial compensation with consideration of their inconvenience. Two scenarios are discussed in this approach with DRP. One where the thermostatically controlled loads (TCLs) are controlled. The thermal comfort of residents and rewards are used to evaluate the demand response performance. The other scenario includes the time-shiftable appliances control with the same framework. The second framework is a three-level hierarchical control framework for large-scale residential DR with a novel bidding scheme and market-level analysis. It comprises of several residential communities, local controllers (LCs), a central controller (CC), and the electricity market. A demand reduction bidding strategy is introduced for the coordination among several LCs under a CC in this framework. Incentives are provided to the participating residential consumers, while considering their preferences, using a continuous reward structure. A simulation study on the 6-bus Roy Billinton Test System with 1;200 residential consumers demonstrates the financial benefits to both the electric utility and consumers

Research on operation optimization of building energy systems based on machine learning

北九州市立大学博士(工学)本研究では、建築エネルギーシステムの運用を最適化するために機械学習を応用し、建築エネルギーシステムの運用コストを削減し、再生可能エネルギーの自給率を向上させることを重点的に扱っています。これらの一連の研究成果は、この分野に新たな知見をもたらし、建築エネルギーシステムの経済的効率を向上させるのに役立っています。In this study, we focus on applying machine learning to optimize the operation of building energy systems, with a primary emphasis on reducing the operational costs of these systems and enhancing the self-sufficiency of renewable energy. This series of research outcomes has brought new insights to the field and contributes to improving the economic efficiency of building energy systems.doctoral thesi

Hierarchical feature extraction from spatiotemporal data for cyber-physical system analytics

With the advent of ubiquitous sensing, robust communication and advanced computation, data-driven modeling is increasingly becoming popular for many engineering problems. Eliminating difficulties of physics-based modeling, avoiding simplifying assumptions and ad hoc empirical models are significant among many advantages of data-driven approaches, especially for large-scale complex systems. While classical statistics and signal processing algorithms have been widely used by the engineering community, advanced machine learning techniques have not been sufficiently explored in this regard. This study summarizes various categories of machine learning tools that have been applied or may be a candidate for addressing engineering problems. While there are increasing number of machine learning algorithms, the main steps involved in applying such techniques to the problems consist in: data collection and pre-processing, feature extraction, model training and inference for decision-making. To support decision-making processes in many applications, hierarchical feature extraction is key. Among various feature extraction principles, recent studies emphasize hierarchical approaches of extracting salient features that is carried out at multiple abstraction levels from data. In this context, the focus of the dissertation is towards developing hierarchical feature extraction algorithms within the framework of machine learning in order to solve challenging cyber-physical problems in various domains such as electromechanical systems and agricultural systems. Furthermore, the feature extraction techniques are described using the spatial, temporal and spatiotemporal data types collected from the systems. The wide applicability of such features in solving some selected real-life domain problems are demonstrated throughout this study

Responsive Building Envelope for Grid-Interactive Efficient Buildings – Thermal Performance and Control

The building sector accounts for 30% of total energy consumption worldwide. Responsive building envelopes (or RBEs) are one of the approaches to achieving net-zero energy and grid-interactive efficient buildings. However, research and development of RBEs are still in the early stages of technologies, simulation, control, and design. The control strategies in prior studies did not fully explore the potential of RBEs or they obtained good performance with high design and deployment costs. A low-cost strategy that does not require knowledge of complex systems is needed, while no studies have investigated online implementations of model-free control approaches for RBEs. To address these challenges, this dissertation describes a multidisciplinary study of the modeling, control, and design of RBEs, to understand mechanisms governing their dynamic properties and synthesis rules of multiple technologies through simulation analyses. Widely applicable mathematical models are developed that can be easily extended for multiple RBE types with validation. Computational frameworks (or co-simulation testbeds) that flexibly integrate multiple control methods and building simulation models are established with higher computation efficiency than that using commercial software during offline training. To overcome the limitations of the control strategies (e.g., rule-based control and MPC) in prior research, a novel easy-to-implement yet flexible ‘demand-based’ control strategy, and model-free online control strategies using deep reinforced learning are proposed for RBEs composed of active insulation systems (AISs). Both the physics-derived and model-free control strategies fully leverage the advantages of AISs and provide higher energy savings and thermal comfort improvement over traditional temperature-based control methods in prior research and demand-based control. The case studies of RBEs that integrate AISs and high thermal mass or self-adaptive/active modules (e.g., evaporative cooling techniques and dynamic glazing/shading) demonstrate the superior performance of AISs in regulating thermal energy transfer to offset AC demands during the synergy. Moreover, the controller design and training implications are elaborated. The applicability assessment of promising RBE configurations is presented along with design implications based on building energy analyses in multiple scenarios. The design and control implications represent an interactive and holistic way to operate RBEs allowing energy and thermal comfort performances to be tuned for maximum efficiency