Voltage Multistability and Pulse Emergency Control for Distribution System with Power Flow Reversal

High levels of penetration of distributed generation and aggressive reactive power compensation may result in the reversal of power flows in future distribution grids. The voltage stability of these operating conditions may be very different from the more traditional power consumption regime. This paper focused on demonstration of multistability phenomenon in radial distribution systems with reversed power flow, where multiple stable equilibria co-exist at the given set of parameters. The system may experience transitions between different equilibria after being subjected to disturbances such as short-term losses of distributed generation or transient faults. Convergence to an undesirable equilibrium places the system in an emergency or \textit{in extremis} state. Traditional emergency control schemes are not capable of restoring the system if it gets entrapped in one of the low voltage equilibria. Moreover, undervoltage load shedding may have a reverse action on the system and can induce voltage collapse. We propose a novel pulse emergency control strategy that restores the system to the normal state without any interruption of power delivery. The results are validated with dynamic simulations of IEEE $13$-bus feeder performed with SystemModeler software. The dynamic models can be also used for characterization of the solution branches via a novel approach so-called the admittance homotopy power flow method.Comment: 13 pages, 22 figures. IEEE Transactions on Smart Grid 2015, in pres

A sustainable village phone model to serve the rural developing world

Wireless technologies have created an unprecedented opportunity for rural customers in the developing world to solve their communication and information problems in an instantaneous, interactive and customized way. The framework of the study focuses on existing mobile village phone model in Bangladesh and suggests ways to make it sustainable through mobile information services marketing. The study has treated ‘village phone’ as a cost effective and interactive channel through which various time befitting information can be marketed to serve customers in the rural settings

CleanTX Analysis on the Smart Grid

The utility industry in the United States has an opportunity to revolutionize its electric grid system by utilizing emerging software, hardware and wireless technologies and renewable energy sources. As electricity generation in the U.S. increases by over 30% from today’s generation of 4,100 Terawatt hours per year to a production of 5,400 Terawatt hours per year by 2030, a new type of grid is necessary to ensure reliable and quality power. The projected U.S. population increase and economic growth will require a grid that can transmit and distribute significantly more power than it does today. Known as a Smart Grid, this system enables two- way transmission of electrons and information to create a demand-response system that will optimize electricity delivery to consumers. This paper outlines the issues with the current grid infrastructure, discusses the economic advantages of the Smart Grid for both consumers and utilities, and examines the emerging technologies that will enable cleaner, more efficient and cost- effective power transmission and consumption.IC2 Institut

Incentive Regulation of Electricity Distribution Networks: Lessons of Experience from Britain

This paper reviews the recent experience of the UK electricity distribution sector under incentive regulation. The UK has a significant and transparent history in implementing incentive regulation in the period since 1990. We demonstrate the successes of this period in reducing costs, prices and energy losses while maintaining quality of service. We also draw out the lessons for other countries in implementing distribution sector reform. We conclude by discussing the place of incentive regulation of networks within the wider reform context, the required legislative framework, the need for appropriate unbundling, the importance of quality of service incentives, the regulatory information requirements and the role of sector rationalisation

Power quality and electromagnetic compatibility: special report, session 2

The scope of Session 2 (S2) has been defined as follows by the Session Advisory Group and the Technical Committee: Power Quality (PQ), with the more general concept of electromagnetic compatibility (EMC) and with some related safety problems in electricity distribution systems. Special focus is put on voltage continuity (supply reliability, problem of outages) and voltage quality (voltage level, flicker, unbalance, harmonics). This session will also look at electromagnetic compatibility (mains frequency to 150 kHz), electromagnetic interferences and electric and magnetic fields issues. Also addressed in this session are electrical safety and immunity concerns (lightning issues, step, touch and transferred voltages). The aim of this special report is to present a synthesis of the present concerns in PQ&EMC, based on all selected papers of session 2 and related papers from other sessions, (152 papers in total). The report is divided in the following 4 blocks: Block 1: Electric and Magnetic Fields, EMC, Earthing systems Block 2: Harmonics Block 3: Voltage Variation Block 4: Power Quality Monitoring Two Round Tables will be organised: - Power quality and EMC in the Future Grid (CIGRE/CIRED WG C4.24, RT 13) - Reliability Benchmarking - why we should do it? What should be done in future? (RT 15

Cost-benefit analysis and valuation uncertainty

This thesis addresses the economic trade-offs between hydropower and fish production, based on an empirical assessment of the costs and benefits of changing the water flow of the Ume/Vindel River in northern Sweden at a major hydropower plant in ways that would reduce its production of electricity but increase the number of wild salmon in the river. A theoretical framework for dynamic cost benefit analysis (CBA) is presented and applied to the salmon passage-hydropower production conflict. The approach has wider applicability than suggested here, and should be useful in other, similar contexts. To obtain estimates for the benefit of increasing the number of wild salmon the contingent valuation method (CVM) was applied. The CVM is a survey-based method developed for measuring values of non-market goods by using willingness to pay (WTP) questions. A new open-ended valuation question, the “classic and interval open-ended” (CIOE) question, was introduced to accommodate the fact that many people have an inability to state their preferences accurately. Interpretation of the resulting valuation uncertainty is more straightforward with this type of question than with other types of valuation question. There are other advantages as well. In addition, methods are introduced for: finding a WTP point estimate for the CIOE question; estimating lower and upper boundaries for the WTP; and for estimating confidence intervals for the total present benefit. An important element of the empirical analysis is that estimated changes in resource conditions are based on detailed river-specific data. The resource dynamic considerations were introduced into both the scenarios and the WTP questions, using an estimated salmon population model for the Vindel River as a base. A model predicting the effects of varying the water flows on the salmon’s migration behaviour was used to estimate the costs of increasing the number of salmon. A total of 1785 individuals received a questionnaire including the CIOE question; the response rate was 66%. Passive use (non-use) values are the major contributors to the benefit (96-517 MSEK) of increasing the wild salmon stock in the Vindel River. The sensitivity analysis suggests that the opportunity costs in terms of lost electricity are typically higher than the estimated benefits

A review of microgrid development in the United States – A decade of progress on policies, demonstrations, controls, and software tools

Microgrids have become increasingly popular in the United States. Supported by favorable federal and local policies, microgrid projects can provide greater energy stability and resilience within a project site or community. This paper reviews major federal, state, and utility-level policies driving microgrid development in the United States. Representative U.S. demonstration projects are selected and their technical characteristics and non-technical features are introduced. The paper discusses trends in the technology development of microgrid systems as well as microgrid control methods and interactions within the electricity market. Software tools for microgrid design, planning, and performance analysis are illustrated with each tool's core capability. Finally, the paper summarizes the successes and lessons learned during the recent expansion of the U.S. microgrid industry that may serve as a reference for other countries developing their own microgrid industries

An Assessment of PIER Electric Grid Research 2003-2014 White Paper

This white paper describes the circumstances in California around the turn of the 21st century that led the California Energy Commission (CEC) to direct additional Public Interest Energy Research funds to address critical electric grid issues, especially those arising from integrating high penetrations of variable renewable generation with the electric grid. It contains an assessment of the beneficial science and technology advances of the resultant portfolio of electric grid research projects administered under the direction of the CEC by a competitively selected contractor, the University of California’s California Institute for Energy and the Environment, from 2003-2014