Ward T. Jewell

Analysis of the Cost per Kilowatt Hour to Store Electricity

This paper presents a cost analysis of grid-connected electric energy storage. Various energy storage technologies are considered in the analysis. Life-cycle cost analysis is used. The results are presented in terms of the cost added to electricity stored and discharged, in US dollar per kilowatt hour. Results are compared with wholesale and retail electricity costs and with the cost of conventional pumped hydro storage.

Limits on cloud-induced fluctuation in photovoltaic generation

The cost and the effect on utility reliability of rapidly changing PV (photovoltaic) generation on a partly-cloudy day were investigated. When cloud shadows move across a PV array, the arrays power output is reduced. It resumes full production when the shadow moves away. The utility must follow these changes with other types of generation. Under certain cloud conditions, these changes can be large and fast. A methodology is presented to assess the cost of such fluctuations in PV generation and their effect on a utilitys ability to serve its load. A case study of one large utility in Kansas is performed using this technique. >

Pitfalls of electric power quality indices

Several indices are in common use for the quantification of electric power quality. These indices are convenient for condensing complex time and frequency domain waveform phenomena into a number. However, a variety of commonly encountered circumstances are not readily accommodated (e.g. quasiperiodic and aperiodic signal components and noninteger multiples of the power frequency). Also, the power acceptability curves have been used as convenient measures of power quality and these curves do not capture three-phase detail of power quality problems. In this paper, the general subject of pitfalls of power quality indices is discussed and suggestions for alleviating these problems are made.

A study of dispersed photovoltaic generation on the PSO system

Results of a study on dispersed photovoltaic (PV) generation on the Public Service Company of Oklahoma (PSO) system with simulated dispersed PV generation are presented. It is found that, with high penetrations of PV, as insolation changes, significant variations in power flows occur on transmission and subtransmission lines that may require changes in system protection and voltage control practices. >

Wireless AMI application and security for controlled home area networks

Compared to the conventional grid, the smart grid requires active participation of consumers to improve the quality and reliability of power delivery. Advanced metering infrastructure (AMI), commonly known as the smart meter, which has the capability of supporting various functions beyond that of recording energy usage, will facilitate this expected increase in consumer participation. Another primary benefit of AMI is load and cost management for the utility. AMI requires a reliable communication system between the smart meter and consumer equipment. This paper identifies wireless networking solutions such as ZigBee as the best mode for such communication. Due to the shared nature of the wireless medium, however, these deployments face security challenges and interference issues. These must be addressed, taking into account the interests of both the utility and the consumer. This paper takes a comprehensive look at wireless security in the AMI based home-area network by identifying a wide range of possible vulnerabilities. Countermeasures that can be used by both the utility company as well as the customer are developed.

Wireless communication for smart grid applications at distribution level — Feasibility and requirements

Smart grid technology places greater demands for reliability on communications infrastructure. This work focuses on identifying requirements for distribution feeder level communications. Due to the large number of distribution components connected to the distribution level feeders, a massively deployed wireless communication network is identified as the potential technology for this application. This network would allow prioritized communication: high priority for abnormal events and system control operations, and low priority communication for asset management tasks. A three-layer wireless communication architecture is proposed in this work to increase the reliability and reduce the latency of event notification. Fault location is considered as an example application to illustrate the proposed architecture.

Toward a Secure Wireless-Based Home Area Network for Metering in Smart Grids

Compared to the conventional grid, the smart grid requires active participation of consumers to improve the quality and reliability of power delivery. The increase in consumer participation is expected from the advanced metering infrastructure (AMI), commonly known as the smart meter, which has the capability of supporting various functions beyond that of recording energy usage. One of the primary objectives of the AMI is to allow load and cost management for the utility. This is envisioned partly through a communication system implemented between the smart meter and consumer equipment, currently deployed using wireless networking solutions such as ZigBee. Due to the shared nature of the wireless medium, however, these deployments face security challenges and interference issues, which must be addressed, taking into account the interests of both the utility company and the consumer. This work takes a comprehensive look at wireless security in the smart-meter-based home area network scenario and identifies possible vulnerabilities. Subsequently, some countermeasures are developed that can be used by both the utility company and the customer and are integrated into a common framework called SecureHAN that can be agreed to by both. In addition, the experiences from implementing the SecureHAN framework using commercial off-the-shelf hardware are described, including possible challenges.

Professional resources to implement the “smart grid”

A widely supported effort to modernize the United States power system has led to an engineering initiative variously known as ‘smart grid’, ‘intelligrid’, “gridwise”, “modern grid”, “perfect grid”, “future grid”, and similarly denominated programs. These efforts generally include features of: self-healing from power disturbance events, enabling active participation by consumers, assuring resilient operation against physical and cyber attack, delivering power quality for digital economy, accommodating all generation and storage options, enabling new products, and optimizing the use of assets. This paper addresses the question as to where engineers needed to address the smart grid will be educated, how they should be trained, and to what levels of comprehension in integrative fields they must be educated.

Risk-Based Allocation of Distribution System Maintenance Resources

Asset management is an important activity in present day distribution system planning and operation. Utilities are constantly striving to optimize the use of resources available for maintenance while ensuring system reliability is within satisfactory limits. This paper proposes a method to allocate maintenance resources to various distribution system assets. To determine the effects of maintenance, a predictive reliability assessment tool is developed. This paper describes the model on which this tool is based. The results obtained from reliability assessment can be used along with an optimizer to allocate resources to various maintenance tasks in a distribution system.

Transformer design in the undergraduate power engineering laboratory

A power engineering laboratory experiment on transformer design is described. In the experiment the student design, builds, and tests a single-phase transformer to specifications provided by the instructor. From initial test results, the transformer is redesigned, and the new design is tested. Standard open and short-circuit tests are then performed to develop a circuit model for the transformer. The model is then used to predict the transformers operation, and the predictions are compared with the values measured in the laboratory. >