Timothy Middelkoop

Experimental Evaluation of Frequency Regulation From Commercial Building HVAC Systems

Automated demand response can be a valuable resource for ancillary services in the power grid. This paper illustrates this value with the first experimental demonstration of frequency regulation from commercial building heating ventilation and air conditioning (HVAC) systems. The experiments were conducted in Pugh Hall, a 40000 sq. ft. commercial building located at the University of Florida. Detailed are the steps required to make this possible, including control architecture, system identification, and control design. Experiments demonstrate: that satisfactory frequency regulation service can be provided by the HVAC system without noticeable effect on the indoor climate, and the ancillary service provided by this system passes the qualification criteria for participating in the Pennsylvania-New Jersey-Maryland (PJM) interconnections frequency regulation market.

How demand response from commercial buildings will provide the regulation needs of the grid

The statement “energy is not storable” is heard in energy conference lectures around the world, even though each person in the audience is sitting in a vast energy storage device. The heat storage in buildings is an enormous untapped resource for providing regulation services. This will be especially important as the grid is subject to more and more volatility from the introduction of power from renewable energy sources. This paper describes how regulation services can be obtained by exploiting the inherent flexibility of HVAC (Heating, Ventilation, Air Conditioning) systems in commercial buildings. A particular simulation test case is considered - A large commercial building at the University of Florida. The conclusions of this research demonstrate that, 1) A simplified model of the building that is adequate for control can be obtained from input-output measurements. In this study, the only control input considered is the supply fan power. 2) Control synthesis to regulate the building air temperature while simultaneously providing regulation to the grid can be cast as an LQR problem that admits a simple closed form solution. 3) Numerical experiments show that for this HVAC system, 15% of fan power capacity can be provided for regulation, while maintaining indoor temperature deviation to no more than ±0.2 °C. Based on these results, we conclude that the HVAC systems in 90, 000 medium-sized commercial buildings can provide the entire regulation service needed by PJM today, without any noticeable change in indoor air quality. The total regulation services that can be potentially provided by all the commercial buildings in the U.S. that have the necessary equipment in place are much higher. Our results indicate that supply fans in existing commercial buildings can provide about 70% of the current regulation capacity needed in the United States.

Restart strategies in optimization: parallel and serial cases

This paper addresses the problem of minimizing the average running time of the Las Vegas type algorithm, both in serial and parallel setups. The necessary conditions for the existence of an effective restart strategy are presented. We clarify the counter-intuitive empirical observations of super linear speedup and relate parallel speedup with the restart properties of serial algorithms. The general property of restart distributions is derived. The computational experiments involving the state-of-the-art optimization algorithm are provided.

An experimental investigation of occupancy-based energy-efficient control of commercial building indoor climate

We present results from a week-long experimental evaluation of a scalable control algorithm for a commercial building heating, ventilation, and air-conditioning (HVAC) system. The experiments showed that the controller resulted in 37% energy savings without sacrificing indoor climate. In contrast to prior work that reports energy savings without a careful measure of the effect on indoor climate, we verify that the controller achieves the energy efficiency improvements without any adverse effect on the indoor climate compared to the buildings baseline controller. This is established from measurements of a host of environmental variables and analysis of before-after occupant survey results. We present a complete system to retrofit existing buildings including the control algorithm and the supporting execution platform which includes the deployment of a wireless sensor network. Results show that there is a large variation in energy savings from zone to zone, which indicates that estimating energy savings potential of novel HVAC control systems is not trivial even from experiments-something that prior work with uniformly positive messages did not emphasize.

Demand side frequency regulation from commercial building HVAC systems: An experimental study

Demand side resources can be valuable for providing inexpensive ancillary services to the power grid. This paper present an experimental demonstration of providing frequency regulation from a commercial building Heating Ventilation and Air Conditioning (HVAC) system. The experiments were conducted in Pugh Hall, a 40,000 sq. ft. commercial building located at the University of Florida. In this paper, we describe the steps required to make this possible, including control architecture, system identification, and control design. The field experiments demonstrate: 1. satisfactory frequency regulation service can be provided by the HVAC system without noticeable effect on the indoor climate, and 2. the ancillary services provided by this system passes the qualification criteria for participating in PJM Interconnections frequency regulation market.

Multi-agent design architecture for Integrated Design Systems

Integrated Design Systems (IDS) represent integration of broad range of high delity knowledge from expert sources in near real time to synthesize and reene design and product realization. Such a system should result in an order of magnitude reduction in product realization time. The characteristics of IDS are: coordination of asynchronous design activities; connict management; interoperability among heterogeneous software and hardware environments to accomplish an eeective collaborative computational system , and to provide tools to facilitate human designers participation. Due to the constant evolution of software tools and techniques, IDS should be able to accommodate changes easily. Multi-Agent Design Architecture (MADA), described in this paper, is designed to address the above requirements and provide additional features. This architecture provides seamless integration of product realization activities across heterogeneous machines, computing platforms, programming languages, data and process representations using distributed intelligent agents. An agent in the context of MADA is an autonomous computational entity which is capable of migrating across computing environments asyn-chronously. These agents posses intelligence in the form of individual goals, beliefs and learning mechanisms, and interact cooperatively to accomplish overall IDS objectives. This paper presents an application of the MADA model to the design of aerospace components. Speciically, we demonstrate the use of integrated design and analysis tools for creating a High Speed Civil Transport exhaust nozzle. Introduction In an increasingly global market, the need for more eecient design methodologies is driven by the requirement to introduce new, cost eeective products into the market quickly. This is especially true in the aerospace industry, where the shrinking defense budgets and international competition are forcing manufacturers to reduce the concept{to{delivery time for products sig-niicantly. In order to achieve these objectives, integrated design systems, which incorporate high delity analysis, experimental testing, manufacturing and cost information at the design stage, have been proposed. Such systems enhance the probability of creating high quality products, without cycling through the product redesign iterations. The use of multidisciplinary knowledge at the product development stage early in the product life cycle presents opportunities for signiicantly impacting the product cost and performance. By catching design errors early, downstream re-engineering costs can be greatly reduced. Proper communications and technology transfer can also result in cost saving innovations or infusion of new technology in the designs. However, as the tools in the integrated design environment increase in both numbers and sophistication, the ability to use these tools eeectively becomes increasingly diicult. …

Experimental evaluation of occupancy-based energy-efficient climate control of VAV terminal units

Results are presented from a nearly week-long experimental evaluation of a scalable control algorithm for a commercial building HVAC system based on real-time measurements of occupancy obtained from motion detectors. The control algorithm decides air flow rate and amount of reheat for each variable air volume terminal box based on real-time measurements of occupancy and space temperature. It is a rule-based controller, so the control computations are simple. The experiments showed that the proposed controller resulted in 37% energy savings over baseline on average without sacrificing indoor climate. In contrast to prior work that reports energy savings without a careful measure of the effect on indoor climate, it is verified that the controller indeed maintains indoor climate as well as the buildings baseline controller does. This verification is performed from measurements of a host of environmental variables and analysis of before/after occupant survey results. A complete system required to retrofit existing buildings with the controller is presented, which includes a wireless sensor network and a software execution platform. Two useful observations from this work are: (i) considerable energy savings—along with compliance with ASHRAE ventilation standards—are possible with simple occupancy-based control algorithms that are easy to retrofit; and (ii) these savings are attained with binary occupancy measurements from motion detectors that do not provide occupancy-count measurements. Results also show that there is a large variation in energy savings from zone to zone and from day to day.

Distributed Collaborative Designs: Challenges and Opportunities

This chapter focuses on distributed product development, and highlights issues that can arise when distributed designer’s attempt to reach a consensus on a good design alternative. Specifically, we address the issue of quality of the overall design as a function of negotiations between different designers, as well as the correctness of the solution. First, we present an iterative agreement protocol for resolving conflict, and examine the solution characteristics and conditions for convergence. Second, we present a diagnostic tool to determine if the design team’s ordering of design choices, after aggregating individual designer’s preferences, is rational. We identify the characteristics of individual designer’s utility functions that lead to irrational outcomes, and present parametric approaches for manipulating utility curves to avoid irrational outcomes.

Measuring the Costs of Custom Products through Better Technology Utilization

This case study details the process of determining the economic feasibility of implementing lean manufacturing in a small mass customization manufacturing company in the medical industry. The case study investigates the information required for a lean implementation and proposes a number of changes to the work procedures (including instrumentation) to obtain the data. A large number of enterprise resource planning systems were evaluated for their suitability to track data in the mass customization environment and the top candidates are compared in the article. The current labor and materials costs are estimated to determine the magnitude of potential savings to support the changes. Based on the analysis the recommended solution has a payback period of approximately two years.

Multiagent Design Architecture for Intelligent Synthesis Environment

The intelligent synthesis environment (ISE) represents the integration of a broad range of high-fidelity knowledge at the design stage to facilitate the product realization process. ISE has the potential of reducing the product realization time by several orders of magnitude. The key characteristics of ISE are integrated evaluation of product life-cycle stages in a virtual environment, coordination of asynchronous design activities, design configuration selection based on multiple design criteria, and interoperability among heterogeneous software and hardware environments to accomplish an effective collaborative computational system. Multiagent design architecture (MADA) is designed to provide a flexible integration framework for ISE. This architecture provides seamless integration of product realization activities across heterogeneous machines, computing platforms, programming languages, data, and process representations using distributed intelligent agents. An agent in the context of MADA is an autonomous computational entity that is capable of migrating across computing environments asynchronously. These agents have intelligence in the form of individual goals, beliefs, learning mechanisms and interact cooperatively to accomplish overall product design objectives. An application of the MADA information framework for the design of aerospace components is presented. Specifically, the use of integrated design and analysis tools for creating a high-speed civil transport exhaust nozzle is demonstrated.