Manisa Pipattanasomporn

Multi-agent systems in a distributed smart grid: Design and implementation

The objective of this paper is to discuss the design and implementation of a multi-agent system that provides intelligence to a distributed smart grid — a smart grid located at a distribution level. A multi-agent application development will be discussed that involves agent specification, application analysis, application design and application realization. The message exchange in the proposed multi-agent system is designed to be compatible with an IP-based network (IP = Internet Protocol) which is based on the IEEE standard on Foundation for Intelligent Physical Agent (FIPA). The paper demonstrates the use of multi-agent systems to control a distributed smart grid in a simulated environment. The simulation results indicate that the proposed multi-agent system can facilitate the seamless transition from grid connected to an island mode when upstream outages are detected. This denotes the capability of a multi-agent system as a technology for managing the microgrid operation.

An Algorithm for Intelligent Home Energy Management and Demand Response Analysis

A home energy management (HEM) system is an integral part of a smart grid that can potentially enable demand response applications for residential customers. This paper presents an intelligent HEM algorithm for managing high power consumption household appliances with simulation for demand response (DR) analysis. The proposed algorithm manages household loads according to their preset priority and guarantees the total household power consumption below certain levels. A simulation tool is developed to showcase the applicability of the proposed algorithm in performing DR at an appliance level. This paper demonstrates that the tool can be used to analyze DR potentials for residential customers. Given the lack of understanding about DR potentials in this market, this work serves as an essential stepping-stone toward providing an insight into how much DR can be performed for residential customers.

Challenges of PHEV penetration to the residential distribution network

As Plug-in Hybrid Vehicles (PHEVs) take a greater share in the personal automobile market, their penetration levels may bring potential challenges to electric utility especially at the distribution level. This paper examines the impact of charging PHEVs on a distribution transformer under different charging scenarios. The simulation results indicate that at the PHEV penetration level of interest, new load peaks will be created, which in some cases may exceed the distribution transformer capacity. In order to keep the PHEVs from causing harmful new peaks, thus making the system more secure and efficient, several PHEV charging profiles are analyzed and some possible demand management solutions, including PHEV stagger charge and household load control, are explored.

Impact of TOU rates on distribution load shapes in a smart grid with PHEV penetration

A smart grid introduces new opportunities and challenges to electric power grids especially at the distribution level. Advanced metering infrastructure (AMI) and information portals enable customers to have access to real-time electricity pricing information, thus facilitating customer participation in demand response. The objective of this paper is to analyze the impact of time-of-use (TOU) electricity rates on customer behaviors in a residential community. Research findings indicate that the TOU rate can be properly designed to reduce the peak demand even when PHEVs are present. This result is insensitive to seasons, PHEV penetration levels and PHEV charging strategies. It is expected that this paper can give policy makers, electric utilities and other relevant stakeholders an insight into the impacts of various TOU pricing schemes on distribution load shapes in a smart grid with PHEV penetration.

Communication network requirements for major smart grid applications in HAN, NAN and WAN

Since the introduction of the smart grid, accelerated deployment of various smart grid technologies and applications have been experienced. This allows the traditional power grid to become more reliable, resilient, and efficient. Despite such a widespread deployment, it is still not clear which communication technology solutions are the best fit to support grid applications. This is because different smart grid applications have different network requirements – in terms of data payloads, sampling rates, latency and reliability. Based on a variety of smart grid use cases and selected standards, this paper compiles information about different communication network requirements for different smart grid applications, ranging from those used in a Home Area Network (HAN), Neighborhood Area Network (NAN) and Wide-Area Network (WAN). Communication technologies used to support implementation of selected smart grid projects are also discussed. This paper is expected to serve as a comprehensive database of technology requirements and best practices for use by communication engineers when designing a smart grid network.

Implications of on-site distributed generation for commercial/industrial facilities

Next-generation distributed generation (DG) is poised to become a key element in our energy future. Recognizing the increased need for a higher reliability energy system and a cleaner environment, This work presents a technique that helps to identify the impact of grid-connected DG on the reliability of on-site electric power. This analysis shows the optimal DG mix at various facility outage costs with and without an emission restriction. The impact of varying the grid reliability and the capital costs of DG units on the decision to invest in backup power is discussed. The break-even costs of microturbines are also estimated at various facility outage costs and microturbine forced outage levels.

Hardware Demonstration of a Home Energy Management System for Demand Response Applications

A Home Energy Management (HEM) system plays a crucial role in realizing residential Demand Response (DR) programs in the smart grid environment. It provides a homeowner the ability to automatically perform smart load controls based on utility signals, customers preference and load priority. This paper presents the hardware demonstration of the proposed HEM system for managing end-use appliances. The HEMs communication time delay to perform load control is analyzed, along with its residual energy consumption.

Intelligent Distributed Autonomous Power Systems (IDAPS)

The electric power system is an enabling infrastructure that supports the operation of other critical infrastructures and thus the economic well-being of a nation. It is, therefore, very important to design for resiliency and autonomous reconfigurability in the electric power grid to guard against man-made and natural disasters. One way to assure such self-healing characteristics in an electric power system is to design for small and autonomous subsets of the larger grid. This paper presents the concept of a specialized microgrid called an intelligent distributed autonomous power system (IDAPS). The IDAPS microgrid aims at intelligently managing customer-owned distributed energy resources such that these assets can be shared in an autonomous grid both during normal and outage operations. The proposed concept is expected to make significant contributions during emergency conditions, as well as creating a new market for electricity transaction among customers.

Load Profiles of Selected Major Household Appliances and Their Demand Response Opportunities

Electrical power consumption data and load profiles of major household appliances are crucial elements for demand response studies. This paper discusses load profiles of selected major household appliances in the U.S., including two clothes washers, two clothes dryers, two air conditioners, an electric water heater, an electric oven, a dishwasher, and two refrigerators. Their electrical power consumption data measured in one-second intervals, together with one-minute data (averaged over 60 one-second readings), are provided in an online data repository (URL: www.ari.vt.edu/research-data/). The data were gathered from two homes in Virginia and Maryland during July-October 2012. In this paper, demand response opportunities provided by these appliances are also discussed.

Flywheel Energy Storage Systems for Ride-through Applications in a Facility Microgrid

Flywheel energy storage (FES) has attracted new interest for uninterruptible power supply (UPS) applications in a facility microgrid. Due to technological advancements, the FES has become a promising alternative to traditional battery storage technologies. This paper aims at developing a tool to demonstrate the use of FES units for securing critical loads during a utility outage in a microgrid environment. The FES is modeled, simulated and evaluated in the MATLAB/SIMULINK® environment. A data center is used to represent a facility microgrid case study. It illustrates how an FES can help improve the load serving capability and provide a highly reliable ride-through capability for critical loads during a utility disturbance. In comparison with batteries, the application of FES for power security is new on the horizon. This limits the availability of experimental data. The simulation model presented in this paper will enable the analysis of short-term ride-through applications of FES during an islanded operation of a facility microgrid. As a result, it can provide a guideline for facility engineers in a data center or other types of facility microgrids to better design their backup power systems based on FES technology, which can be used in combination with traditional fuel-based generators.