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Low Voltage General Purpose Dry Type Transformers
An Overview of Dry, Liquid & Cast Coil Transformers. What is Best for My Application? Ken Box, P.E. - Schneider Electric John Levine, P.E. - Levine Lectronics & Lectric Low Voltage General Purpose Dry Type Transformers Confidentia l Property of Schneider Electric | Selecting & Sizing Dry Type Transformers From EC&M Magazine http://www.csemag.com/single-article/selecting- sizing-transformers-for-commercial- buildings/4efa064775c5e26f27bfce4f0a61378e.htm l 3 Phase: 15 – 1000kVA, 600V max primary 1 Phase: 15 – 333 kVA, 600V max primary Specialty transformers, custom ratings, exceptions Insulation System The insulation system is the maximum internal temperature a transformer can tolerate before it begins to deteriorate and eventually fail. Most ventilated transformers use a Class 220°C insulation system. This temperature rating is the sum of the winding rise temperature, normally 150°C, the maximum ambient temperature, 40°C, and the hot spot allowance inside the coils, 30°C. Insulation = Winding rise + Coil Hot Spot + Max Ambient For ventilated transformers, 80°C and 115°C are also common low temperature rise transformer ratings. The standard winding temperature is 150°C for a ventilated transformer. All three of these temperature rise ratings utilize the 220°C insulation system. Insulation Class 220 insulation Class 180 insulation 40 C ambient 40 C ambient + 150 C average rise + 115 C average rise + 30 C hotspot + 25 C hotspot ______ ______ 220 C hotspot temp. 180 C hotspot temp. Class 200 Insulation Class 150 Insulation 40 C ambient 40 C ambient + 130 C average rise + 80 C average rise + 30 C hotspot + 30 C hotspot ______ ______ 200 C hotspot temp. -
Mandatory Disclosure Part-2
COLLEGE OF ENGINEERING AND TECHNOLOGY, BAMBHORI POST BOX NO. 94, JALGAON – 425001. (M.S.) NBA Accredited Website : www.sscoetjalgaon.ac.in Email : [email protected] Mandatory Disclosure Part-II November 2009 NORTH MAHARASHTRA UNIVERSITY, JALGAON STRUCTURE OF TEACHING AND EVALUATION S.E .(CIVIL ENGINEERING) First term Sr. Subject Teaching Scheme Examination Scheme No. Hours/week Paper Lectures Tutorial Practical Duration Paper TW PR OR Hours 1 Strength of Material 4 1 -- 3 100 25 -- -- 2 Surveying-I 4 -- 2 3 100 25 50 -- 3 Building Construction and 4 -- 4 3 100 25 -- 25 Materials 4 Concrete Technology 4 -- 2 3 100 25 -- 25 5 Engineering Mathematics- 4 1 -- 3 100 25 -- -- III 6 Computer Graphics -- -- 2 25 Total 20 2 10 -- 500 150 50 50 Grand Total 32 750 SECOND TERM Sr. Subject Teaching Scheme Hours/week Examination Scheme No. Paper Lectures Tutorial Practical Duration Paper TW PR OR Hours 1 Theory of Structures-I 4 1 -- 3 100 25 -- -- 2 Surveying-II 4 -- 2 3 100 25 50 -- 3 Building Design and 4 -- 4 4 100 50 -- 25 Drawing 4 Fluid Mechanics-I 4 1 2 3 100 25 -- 25 5 Engineering Geology 4 -- 2 3 100 25 -- -- 20 2 10 -- 500 15 50 50 0 Total Grand 32 750 Total NORTH MAHARASHTRA UNIVERSITY, JALGAON. SYLLABUS OF SECOND YEAR (CIVIL) TERM-IST (w.e.f. 2006-07) STRENGTH OF MATERIALS ---------------------------------------------------------------------------------------------------------------- Teaching Scheme: Examination Scheme: Lectures: 4 Hours/Week Theory Paper: 100 Marks(3 Hrs) Tutorials: 1 Hour/Week Term Work: 25 Marks ---------------------------------------------------------------------------------------------------------------- UNIT-I: ( 11 Hrs., 20 marks) Normal stress & strain, Hooke’s law. -
Classification of Transformers Family
TECHNOLOGY BASICS ABSTRACT Transformers are used in the electrical Classification of networks everywhere: in power plants, substations, industrial plants, buil- dings, data centres, railway vehicles, Transformers Family ships, wind turbines, in the electronic devices, the underground, and even 1. Introduction undersea. The focus of this article is on transformers applied in the trans- ransformers basically perform a of transformers in the most systematic way mission of energy, usually called pow- very simple function: they increase rather than elaborating on each type. er transformers. Due to very versatile Tor decrease voltage and current for requirements and restrictions in the the electric energy transmission. It is pre- The most important international orga- numerous applications, ranging from cisely stated what a transformer is in the nisations with focus on such transfor- a subsea transformer to a wind turbine International Electrotechnical Vocabula- mers are IEC1 through E14, its technical transformer, a small distribution trans- ry, Chapter 421: Power transformers and committee for the world standards; IEEE2 former to a large phase shifter trans- reactors [1]: through the Transformers Committee former, it is very difficult to organise a mainly for the American standards and structured overview of the transformer “A static piece of apparatus with two or CIGRE3 through the Study Committee types. Also, different companies sup- mo re windings which, by electromag- A2 Transformers which mainly produ- ply different markets and each have netic ind uction, transforms a system ces technical brochures and guidelines their own classification of the trans- of alterna ting voltage and current into on many subjects. Main standards for formers, which makes the transformer another system of voltage and current the transformers in question are the IEC family even more difficult to organise. -
Mutual Inductance and Transformer Theory Questions: 1 Through 15 Lab Exercise: Transformer Voltage/Current Ratios (Question 61)
ELTR 115 (AC 2), section 1 Recommended schedule Day 1 Topics: Mutual inductance and transformer theory Questions: 1 through 15 Lab Exercise: Transformer voltage/current ratios (question 61) Day 2 Topics: Transformer step ratio Questions: 16 through 30 Lab Exercise: Auto-transformers (question 62) Day 3 Topics: Maximum power transfer theorem and impedance matching with transformers Questions: 31 through 45 Lab Exercise: Auto-transformers (question 63) Day 4 Topics: Transformer applications, power ratings, and core effects Questions: 46 through 60 Lab Exercise: Differential voltage measurement using the oscilloscope (question 64) Day 5 Exam 1: includes Transformer voltage ratio performance assessment Lab Exercise: work on project Project: Initial project design checked by instructor and components selected (sensitive audio detector circuit recommended) Practice and challenge problems Questions: 66 through the end of the worksheet Impending deadlines Project due at end of ELTR115, Section 3 Question 65: Sample project grading criteria 1 ELTR 115 (AC 2), section 1 Project ideas AC power supply: (Strongly Recommended!) This is basically one-half of an AC/DC power supply circuit, consisting of a line power plug, on/off switch, fuse, indicator lamp, and a step-down transformer. The reason this project idea is strongly recommended is that it may serve as the basis for the recommended power supply project in the next course (ELTR120 – Semiconductors 1). If you build the AC section now, you will not have to re-build an enclosure or any of the line-power circuitry later! Note that the first lab (step-down transformer circuit) may serve as a prototype for this project with just a few additional components. -
Class-E Audio Modulated Tesla Coil Instruction Manual
Class-E Audio Modulated Tesla Coil CCllaassss--EE AAuuddiioo MMoodduullaatteedd TTeessllaa CCooiill IInnssttrruuccttiioonn MMaannuuaall Eastern Voltage Research, LLC May 19, 2017 REV F − 1 − http://www.EasternVoltageResearch.com Class-E Tesla Coil Instruction Manual Class-E Audio Modulated Tesla Coil BOARD REVISION C This manual only applies to the new Revision C PCB boards. These boards can be identified by their red or green silkscreen color as well as the marking SC2076 REV C which is located underneath the location for T41 on the upper right of the PCB board. May 19, 2017 REV F − 2 − http://www.EasternVoltageResearch.com Class-E Tesla Coil Instruction Manual Class-E Audio Modulated Tesla Coil AGE DISCLAIMER THIS KIT IS AN ADVANCED, HIGH POWER SOLID STATE POWER DEVICE. IT IS INTENDED FOR USE FOR INDIVIDUALS OVER 18 YEARS OF AGE WITH THE PROPER KNOWLEDGE AND EXPERIENCE, AS WELL AS FAMILIARITY WITH LINE VOLTAGE POWER CIRCUITS. BY BUILDING, USING, OR OPERATING THIS KIT, YOU ACKNOWLEDGE THAT YOU ARE OVER 18 YEARS OF AGE, AND THAT YOU HAVE THOROUGHLY READ THROUGH THE SAFETY INFORMATION PRESENTED IN THIS MANUAL. THIS KIT SHALL NOT BE USED AT ANY TIME BY INDIVIDUALS UNDER 18 YEARS OF AGE. May 19, 2017 REV F − 3 − http://www.EasternVoltageResearch.com Class-E Tesla Coil Instruction Manual Class-E Audio Modulated Tesla Coil SAFETY AND EQUIPMENT HAZARDS PLEASE BE SURE TO READ AND UNDERSTAND ALL SAFETY AND EQUIPMENT RELATED HAZARDS AND WARNINGS BEFORE BUILDING AND OPERATING YOUR KIT. THE PURPOSE OF THESE WARNINGS IS NOT TO SCARE YOU, BUT TO KEEP YOU WELL INFORMED TO WHAT HAZARDS MAY APPLY FOR YOUR PARTICULAR KIT. -
Zilano Design for "Reverse Tesla Coil" Free Energy Generator
Zilano Design for "Reverse Tesla Coil" Free Energy Generator Summary Document A for Beginners by Vrand Thank you Zilano for sharing your very interesting design and we all wish you the very best, keep up the good work! Energetic Forum http://www.energeticforum.com/renewable-energy/ This is a short document describing the work of Zilano as posted on the Don Smith Devices thread at the Energetic Forum so that other researchers can experiment and build their own working free energy generator to power their homes. Zilano stated that this design was based on the combination works of Don Smith, Tesla, Dynatron, Kapanadze and others. Design Summary Key points : - "Reverse Tesla Coil" (in this document) - Conversion of high frequency AC (35kHz) to 50-60Hz (not in this document) "Reverse Tesla Coil" is where the spark gap pulsed DC voltage from a 4000 volt (4kv) 30 kHz NST (neon sign transformer) goes into an air coil primary P of high inductance (80 turns thin wire) that then "steps down" the voltage to 240 volts AC a low inductance Secondary coil centered over the primary coil (5 turns bifilar, center tap, thick wire) with high amperage output. The high frequency (35kHz) AC output can then power loads (light bulbs) or can be rectified to DC to power DC loads. Copper coated welding rods can be inserted into the air coil to increase the inductance of the air coil primary that then increases the output amperage from the secondary coil to the loads. See the below diagram 1 : Parts List - NST 4KV 20-35KHZ - D1 high voltage diode - SG1 SG2 spark gaps - C1 primary tuning HV capacitor - P Primary of air coil, on 2" PVC tube, 80 turns of 6mm wire - S Secondary 3" coil over primary coil, 5 turns bifilar (5 turns CW & 5 turns CCW) of thick wire (up to 16mm) with center tap to ground. -
Sri Venkateswara College of Engineering and Technology Department of Electrical & Electronics Engineering EE 6504-Electrical
Sri Venkateswara College of Engineering and Technology Department of Electrical & Electronics Engineering EE 6504-Electrical Machines-II UNIT-I 1. Why a 3-phase synchronous motor will always run at synchronous speed? Because of the magnetic coupling between the stator poles and rotor poles the motor runs exactly at synchronous speed. 2. What are the two classification synchronous machines? The classification synchronous machines are: i. Cylindrical rotor type ii. Salient pole rotor type 3. What are the essential features of synchronous machine? i. The rotor speed is synchronous with stator rotating field. ii. Varying its field current can easily vary the speed. iii. It is used for constant speed operation. 4. Mention the methods of starting of 3-phase synchronous motor. a. A D.C motor coupled to the synchronous motor shaft. b. A small induction motor coupled to its shaft.(pony method) c. Using damper windings –started as a squirrel cage induction motor. 5. What are the principal advantages of rotating field system type of construction of synchronous machines? · Form Stationary connection between external circuit and system of conditions enable the machine to handle large amount of volt-ampere as high as 500 MVA. · The relatively small amount of power required for field system can be easily supplied to the rotating field system via slip rings and brushes. · More space is available in the stator part of the machine for providing more insulation to the system of conductors. · Insulation to stationary system of conductors is not subjected to mechanical stresses due to centrifugal action. · Stationary system of conductors can easily be braced to prevent deformation. -
Electricity Today Issue 4 Volume 17, 2005
ET_4_2005 6/3/05 10:41 AM Page 1 A look at the upcoming PES IEEE General Meeting see page 5 ISSUE 4 Volume 17, 2005 INFORMATION TECHNOLOGIES: Protection & Performance and Transformer Maintenance PUBLICATION MAIL AGREEMENT # 40051146 Electrical Buyer’s Guides, Forums, On-Line Magazines, Industry News, Job Postings, www.electricityforum.com Electrical Store, Industry Links ET_4_2005 6/3/05 10:41 AM Page 2 CONNECTINGCONNECTING ...PROTECTING...PROTECTING ® ® ® HTJC, Hi-Temperature Joint Compound With a unique synthetic compound for "gritted" and "non-gritted" specifications, the HTJC high temperature "AA" Oxidation Inhibitor improves thermal and electrical junction performance for all connections: • Compression Lugs and Splices for Distribution and Transmission • Tees, Taps and Stirrups on any conductor • Pad to Pad Underground, Substation and Overhead connections For oxidation protection of ACSS class and other connector surfaces in any environment (-40 oC to +250 oC), visit the Anderson ® / Fargo ® connectors catalogue section of our website www.HubbellPowerSystems.ca Anderson® and Fargo® offer the widest selection of high performance inhibitor compounds: Hubbell Canada LP, Power Systems TM ® ® 870 Brock Road South Inhibox , Fargolene , Versa-Seal Pickering, ON L1W 1Z8 Phone (905) 839-1138 • Fax: (905) 831-6353 www.HubbellPowerSystems.ca POWER SYSTEMS ET_4_2005 6/3/05 10:41 AM Page 3 in this issue Publisher/Executive Editor Randolph W. Hurst [email protected] SPECIAL PREVIEW Associate Publisher/Advertising Sales 5 IEEE PES General Meeting has -
Review of Ground Fault Protection Methods for Grounded, Ungrounded, and Compensated Distribution Systems
REVIEW OF GROUND FAULT PROTECTION METHODS FOR GROUNDED, UNGROUNDED, AND COMPENSATED DISTRIBUTION SYSTEMS Jeff Roberts, Dr. Hector J. Altuve, and Dr. Daqing Hou Schweitzer Engineering Laboratories, Inc. Pullman, WA USA ABSTRACT This paper reviews ground fault protection and detection methods for distribution systems. First, we review and compare medium-voltage distribution-system grounding methods. Next, we describe directional elements suitable to provide ground fault protection in solidly- and low- impedance grounded distribution systems. We then analyze the behavior of ungrounded systems under ground fault conditions and introduce a new ground directional element for these systems. Then we examine the behavior of compensated systems during ground faults and describe traditional fault detection methods. We conclude by introducing new ground fault detection methods for compensated systems. INTRODUCTION Ground fault current magnitudes depend on the system grounding method. Solidly- and low- impedance grounded systems may have high levels of ground fault currents. These high levels typically require line tripping to remove the fault from the system. Ground overcurrent and directional overcurrent relays are the typical ground fault protection solution for such systems. However, high-impedance ground fault detection is difficult in multigrounded four-wire systems, in which the relay measures the ground fault current combined with the unbalance current generated by line phasing and configuration and load unbalance. Ungrounded systems have no intentional ground. For a single-line-to-ground fault on these systems, the only path for ground current to flow is through the distributed line-to-ground capacitance of the surrounding system and of the two remaining unfaulted phases of the faulted circuit. -
Advanced Power Transformer Diagnostics – Detection of Core-Ground Issues
CIGRE-346 2020 CIGRE Canada Conference Toronto, Ontario, October 19-22, 2020 Advanced Power Transformer Diagnostics – Detection of Core-Ground Issues ALI NADERIAN JAHROMI1, PRANAV PATTABI1, JAFAR MOHAMMADI1, MOHSEN TANGSIRI2 1METSCO Energy Solutions, Canada 2MS Hydro Power Plant, Iran SUMMARY The typical construction of a power transformer results in a high potential being induced in the core, due to the electromagnetic coupling that exists between the core and winding assembly. The transformer core is normally grounded at a single point, to safely divert this induced voltage to the local ground. The core-ground connection also provides a low- resistance path under a short circuit scenario between the transformer winding and core. This allows for the reliable operation of the associated transformer protection relay unit. The isolation of core from ground forms an integral part of the transformer’s insulation system. The core-ground connection must be accessible and further removable for testing. Any issue with the transformer core-ground connection can result in improper grounding, the presence of multiple ground paths, unintentional core-grounds, and a floated core. Multiple core-grounds are created when the core comes into direct contact with the grounded internal metallic structure of a power transformer. Based on the value of the core-to-ground resistance, sustained heating effects can be caused by circulating currents that can eventually result in the melting of the transformer core. This paper outlines the use of diagnostic procedures such as Dissolved Gas Analysis (DGA) and Duval’s Pentagon, Dielectric Frequency Response (DFR) testing, and core-to-ground resistance testing for identifying core-ground defects in power transformers. -
How Understanding a Railway's Historic Evolution Can Guide Future
College of Engineering, School of Civil Engineering University of Birmingham Managing Technical and Operational Change: How understanding a railway’s historic evolution can guide future development: A London Underground case study. by Piers Connor Submitted as his PhD Thesis DATE: 15th February 2017 University of Birmingham Research Archive e-theses repository This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder. Managing Technical & Operational Development PhD Thesis Abstract The argument for this thesis is that patterns of past engineering and operational development can be used to support the creation of a good, robust strategy for future development and that, in order to achieve this, a corporate understanding of the history of the engineering, operational and organisational changes in the business is essential for any evolving railway undertaking. It has been the objective of the author of this study to determine whether it is essential that the history and development of a railway undertaking be known and understood by its management and staff in order for the railway to function in an efficient manner and for it to be able to develop robust and appropriate improvement strategies in a cost-effective manner. -
Birmingham Local Section
264 MORRIS AND LISTER: THE TESTING OF [Birmingham, BIRMINGHAM LOCAL SECTION. THE TESTING OF TRANSFORMERS AND TRANSFORMER IRON. By D. K. MORRIS, Ph.D., and G. A. LISTER, Associate Members. (Paper read on April 25, 1906.) SYNOPSIS.—1. Introduction. 2. Regulation diagram. 3. Diagram of voltage charac- teristic. 4. The short-circuit test. 5. Proposed standard transformer test. 6. The 3-point wattmeter method. 7. Standard tests for—(a) core losses: separation by constant-frequency test ; (6) copper losses; (c) efficiency; (d) heating ; (e) regulation. 8. The auxiliary transformer. 9. Special tests— (a) by means of extra turns ; (b) at half power factor; (c) out-of-phase test; (<i) 3-phase transformers. 10. Hysteresis by slow cyclic change—(a) method of constant induced voltage ; (b) theory; (c) application to testing of small samples. 11. Conclusion. APPENDIX.—The 3-point method. Temperature by the wattmeter. Improvements in the constant induced voltage method. Separation of hysteresis from eddy- current loss. 1. INTRODUCTION. In the testing of transformers the principal- qualities which may have to be investigated are :— (a)' Core losses. (b) Copper losses at all loads. (c) Efficiency at light loads as well as full load. (d) Heating at full load. (e) Regulation on all loads and power factors. (/) Insulation (not dealt with in the paper). The designer and manufacturer of the transformers may also require to know the extent to which the core loss is caused by hysteresis or eddy currents. In addition, it would be useful to deter- mine the excellence of the built-up magnetic circuit, having reference to the permeability of the iron and the low magnetic resistance of the joints.