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Showing posts from February, 2012

CAPACITOR FUSING APPLICATION GUIDE RULES

CAPACITOR FUSING APPLICATION GUIDE RULES Basic points to consider in fusing a capacitor in electric system network 1) Purpose of fusing:                 a. to isolate faulted bank from system                 b. to protect against bursting                 c. to give indication                 d. to allow manual switching (fuse control)                 e. to isolate faulted capacitor from bank 2) Recommended rating:                                a. The continuous-current capability of the fuse should be at least 165 percent of the normal capacitor-bank (for delta and floating wye banks the factor may be reduced to 150 percent if necessary).                 b. The total clearing characteristics of the fuse link must be coordinated with the capacitor "case bursting" curves. 3)  Tests have shown that expulsion fuse links will not satisfactorily protect  against violent rupture where the fault current through the capacitor is greater than 5000 amperes. 4)  The c

FUSE APPLICATION GUIDE RULES

FUSE APPLICATION GUIDE RULES Basic points to consider in installing fuses in electrical system network 1)  Cold load pickup -  after 15 minute outage,  200% for.5 seconds                                                                          140% for 5 seconds                                        after 4 hrs, all electric  300% for 5 minutes 2)  "Damage" curve - 75% of minimum melt 3)  Two expulsion fuses cannot be coordinated if the available fault current is great enough to indicate an interruption of less than .8 cycles. 4)  "T" - SLOW and "K" - FAST 5)  Current limiting fuses can be coordinated in the sub-cycle region. 6)  Capacitor protection: The fuse should be rated for 165% of the normal capacitor current.  The fuse should also clear within 300 seconds for the minimum short circuit current. If current exceeds the maximum case rupture point, a current limiting fuse must be used. Current limiting fuses should be used if a s

HIGH IMPEDANCE FAULTS CHARACTERIZATION TECHNICAL PAPER

Authored by: Alicia Valero Masa, Jean-Claude Maun, Stefan Werben ABSTRACT High Impedance Fault (HIF) detection is increasingly a concern of distribution network protection engineers. Practical methods to deal with HIFs are in great demand in the USA, where HIFs are not detected by conventional protection devices. The lack of a globally accepted description of HIFs is a difficulty for HIF detection. In the effort to understand and explain HIFs, we have carried out a theoretical study, simulations, laboratory tests, and studied field recordings. To study the influence of factors affecting HIFs, we have developed an Alternative Transients Program (ATP) simulation model and designed laboratory tests. HIF field recordings provided by Iberdrola Distribución Eléctrica S.A.U. validate the findings. In this paper, we present a  HIF characterization to improve HIF detection. This accurate characterization of HIFs allows us to develop a pattern recognition method to detect HIFs.

ELECTRIC MOTOR BRAKING METHODS TUTORIALS

ELECTRIC MOTOR BRAKING METHODS TUTORIALS What are the methods in stoppng/braking an electric motor? MECHANICAL BRAKING Mechanical braking with magnetic lifting is the technique most widely used for the braking of electric motors . At standstill brakes of this type provide a holding torque, and are therefore used where loss of braking in the event of power failure could be dangerous. However, in certain cases it may be necessary to lift the brake without starting the motor. This can be done by supplying the brake coil from a separate power source, or with a manual release device. The mechanical brakes used for electric motors are shoe, multiple-plate or disc brakes. ABB Motors brakes are disc brakes with asbestos-free brake pads or linings. During braking , the braking torque is constant with mechanical braking . At standstill the brake has a holding torque. On some brakes the braking torque can be reduced for softer deceleration. When the motor is started again, the holdin

PRODUCT REVIEW: RM-18 WATTHOUR PORTABLE METER TEST SYSTEM

PRODUCT REVIEW: RM-18 WATTHOUR PORTABLE METER TEST SYSTEM Review on RM-18: Product for ensuring kilowatt-hour meter accuracy Non-technical loss in an electric utility in the form of pilferage can be in many forms. Many ways of stealing electric power can be done in the current technology today. Direct tapping, installation of jumpers, and meter tampering are just a few of those methods used to pilfer energy. Among the methods mentioned, the most rampant method would be through tampering of meter. Likewise, meter tampering can also have number of methods in doing so; the most common would be adjusting the accuracy of the meter . As we all know, meter accuracy is very important not only to the utility but also to the consumer since this is the one responsible for reflecting the actual consumption of the user. Unfortunately, criminal minds use this knowledge for their own benefit by opening the meter and adjusting its accuracy . Reports are usually given to the utility regarding a

A NEW APPROACH FOR DESIGN AND IMPLEMENTATION OF AMR IN SMART METER TECHNICAL PAPER

Authored by: Ms.Priya S.Kamble and Ms.Sonali T.Bodkhe ABSTRACT This paper elucidates a current measurement method for wide range residual current measurement. The paper discusses Automated Meter Reading , a technology used to automate the task of reading consumption records of subscribers. The problem is first defined in terms of Utilities, critical infrastructure needs, revenue protection and operational efficiencies. Various drivers as well as impediments within such scopes are the defined. Moreover, different technologies proposed and implemented are discussed. The paper concludes by capturing the conclusions obtained and suggestions for further improvements of such technologies for future applications.

AMR-AUTOMATED METER READING SYSTEM FOR LOSS REDUCTION DUE TO ERROR READING ISSUES

AMR System for electric utility use in automated meter reading AMR system or the Automated Meter Reading System is a modern technology application of automatically collecting information, status report, and reading from utility meters like in the water, gas and energy. This automation process is made possible through the use of digital communication techniques such that it saves utility providers the expense of periodic trips to each physical location to read a meter.

LOAD PROFILE SHAPE OBJECTIVES FOR DEMAND SIDE MANAGEMENT TUTORIALS

LOAD PROFILE SHAPE OBJECTIVES FOR DEMAND SIDE MANAGEMENT TUTORIALS Load profile management for demand side management action plan Customer load profile is an excellent guide in implementing demand side management . This serves as a monitoring tool for in which action plan method is to be applied. Levelling the load profile behaviour of the customer load will maximize the use the utilities generation capacity thus lowering the load factor . This is usually done by shifting some customer loads from peak loads hours to off-peak hours. Alternatively, off-peak load hours can also be increased to reduce the company’s load factor . PEAK CLIPPING Peak clipping refers to the reduction of utility loads during peak demand periods. This can defer the need for additional generation capacity. The net effect is a reduction in both peak demand and total energy consumption. This is usually implemented by direct utility control of consumer appliances or end use equipment. VALLEY FILLING Valley fil

DEMAND SIDE MANAGEMENT BEST PRACTICES GUIDE BOOK PDF

Guidebook prepared by International Institute for Energy Conservation (IIEC) EXECUTIVE SUMMARY The International Institute for Energy Conservation (IIEC) has developed this Guidebook as part of the Pacific Island Demand-Side Management (DSM) initiative, a programme funded by the United Nations Department of Economic and Social Affairs (UNDESA). The purpose of this Guidebook is to facilitate the development, financing and implementation of Demand-Side Management (DSM) projects in the Pacific Island Countries (PICs), by providing guidelines for DSM programme development and documented international DSM case studies. This Guidebook introduces the DSM concepts, gives the reader a perspective on the DSM opportunities in the PICs and provides a compendium of case studies from different sectors and countries and a proposed methodology for implementation of DSM in the Pacific Island utilities.

DEMAND SIDE MANAGEMENT FOR LOSS REDUCTION IN ELECTRIC POWER SYSTEM

Reducing electric power loss using the demand side of the utility Reducing losses in an electric utility can be done in many different ways each of its own advantages and disadvantages. Majority of this loss reduction program focuses on the supply side of the utility. To name a few includes conductor wire upgrades, increasing the primary voltages, balancing the currents in each phases, adding line capacitors and many more.

ENERGY THEFT: TYPICAL LOCATION FOR ELECTRIC PILFERAGE OCCURENCE

Where electric pilferages are usually practiced and applied? Energy theft or pilferage is one of the common causes of non-technical loss in any electric distribution utility. These pilferages  are the losses that are not caused by the electrical characteristics of the system rather it is the result of the intentional attempt to harness power for free. For detailed discussion regarding the non-technical losses, you can always look back to the previous topics .

ENERGY THEFT: A COMPARATIVE ANALYSIS TECHNICAL PAPER

Authored by: Thomas B. Smith ABSTRACT Electricity theft can be in the form of fraud (meter tampering), stealing (illegal connections), billing irregularities, and unpaid bills. Estimates of the extent of electricity theft in a sample of 102 countries for 1980 and 2000 are undertaken. The evidence shows that theft is increasing in most regions of the world. The financial impacts of theft are reduced income from the sale of electricity and the necessity to charge more to consumers. Electricity theft is closely related to governance indicators, with higher levels of theft in countries without effective accountability, political instability, low government effectiveness and high levels of corruption. Electricity theft can be reduced by applying technical solutions such as tamper-proof meters, managerial methods such as inspection and monitoring, and in some cases restructuring power systems ownership and regulation.