WELCOME TO THE TRANSFORMERS COMMITTEE WEBSITE!
The Transformers Committee is one of the largest and most active of the17 technical committees within the IEEE Power and Energy Society (PES). The Committee is comprised of technical and managerial representatives from manufacturers, consultants, vendors and end users of electrical transformers and components. The continuing scope of the Committee is to develop and update standards and guidelines for the design, testing, repair, installation, operation and maintenance of transformers, reactors and associated components that are used within electric utility and industrial power systems.
Jixipix pastello pro 1 1 110. NOTICES:
Please regularly check the Calendar/Events page for web/conf call meetings. We will make every effort to publicize them in advance when notified.
FALL MEETING NOTICE
Transformers: Revenge of the Fallen (or simply Transformers 2) is a 2009 American science fiction action film directed by Michael Bay and executive produced by Steven Spielberg. It is a sequel to 2007's Transformers and the second installment in the live-action Transformers series taking place two years after Transformers. Trivia 1001 Video Games Transformers appears in the book 1001 Video Games You Must Play Before You Die by General Editor Tony Mott. Cancelled sequel There was sequel planned based on the Cybertron series, but Atari moved Melbourne House onto another project, effectively canceling it. Cut content Some characters were dropped from the game. Transformers: Revenge of the Fallen is a 2009 American science fiction action film directed by Michael Bay and is based on the Transformers toy line. It is the sequel to 2007's Transformers, as well as the second installment in the live-action Transformers film series. Some transformer winding primary (usually high-voltage) connecting wires are of many types. May be labeled as H 1, H 2 (sometimes H 0 if it is internally designed to be grounded) and X 1, X2 and sometimes an X 3 tap may be present. Sometimes a second isolated winding (Y 1, Y 2, Y 3) (and third (Z 1, Z 2, Z 3) may also be available on the same.
The On Demand videos of the Newcomers presentation, Awards Ceremony, and Thursday Tutorials are available on the Fall 2020 Virtual Meeting page. The committee password is required for the Thursday Tutorials. Enjoy!
MEMORIAL
It is with regret that we report the passing of Dr. Jitka Fuhr. Dr. Fuhr received her degree in electrical engineering from the Tech. Univ. in Karlsruhe Germany and her PHD at the Tech. Univ Darmstadt Germany. She worked for BBC Mannheim (Germany), Polytechnic Univ. (NY, USA), ABB Corp Research Center (Baden, Switzerland), Swiss utility BKW Energy Ltd and finally as an independent consultant (AF Engineers and Consultants). Dr. Fuhr and her contributions in the field of partial discharge will be greatly missed.
TRAINING
IEEE SA Training & Development has launched a new course “Working Group Chair Fundamentals”. To access the training, click here. You do not need to be an IEEE member to receive this training free of charge.
LAST MEETING:
Fall 2019 – Columbus, Ohio, October 27 – 31, 2019
Presentations (see above Mtg Page)
Attendance: By Company, By Name
Presentations (see above Mtg Page)
Attendance: By Company, By Name
UPCOMING MEETINGS:
Fall 2020 – VIRTUAL MEETING, October 19 – 22, 2020*
Spring 2021 – Toronto, Ontario CANADA April 25-29, 2021**
Fall 2021 – Milwaukee, Wisconsin USA, October 17-21, 2021**
Spring 2022 – Denver, Colorado USA, March 27 – 31, 2022**
Fall 2022 – Charlotte, North Carolina USA, October 16 – 20, 2022**
* Firm date
** Confirmed date and location
Break Sponsors Lis
Spring 2021 – Toronto, Ontario CANADA April 25-29, 2021**
Fall 2021 – Milwaukee, Wisconsin USA, October 17-21, 2021**
Spring 2022 – Denver, Colorado USA, March 27 – 31, 2022**
Fall 2022 – Charlotte, North Carolina USA, October 16 – 20, 2022**
* Firm date
** Confirmed date and location
Break Sponsors Lis
Instrument transformers are high accuracy class electrical devices used to isolate or transform voltage or current levels. The most common usage of instrument transformers is to operate instruments or metering from high voltage or high current circuits, safely isolating secondary control circuity from the high voltages or currents. The primary winding of the transformer is connected to the high voltage or high current circuit, and the meter or relay is connected to the secondary circuit.
Instrument transformers may also be used as an isolation transformer so that secondary quantities may be used in phase shifting without affecting other primary connected devices.[1]
Current transformer[edit]
Current transformers used in metering equipment for three-phase 400 ampere electricity supply
SF6 110 kV current transformer TGFM series, Russia
Current transformers (CT) are a series connected type of instrument transformer. They are designed to present negligible load to the supply being measured and have an accurate current ratio and phase relationship to enable accurate secondary connected metering.
Current transformers are often constructed by passing a single primary turn (either an insulated cable or an uninsulated bus bar) through a well-insulated toroidal core wrapped with many turns of wire. This affords easy implementation on high voltage bushings of grid transformers and other devices by installing the secondary turn core inside high-voltage bushing insulators and using the pass-through conductor as a single turn primary. Flinto 26 0 5 download free.
Clampmeter utilizing a split core
A current clamp uses a current transformer with a split core that can be easily wrapped around a conductor in a circuit. This is a common method used in portable current measuring instruments but permanent installations use more economical types of current transformer.Specially constructed wideband CTs are also used, usually with an oscilloscope, to measure high frequencywaveforms or pulsed currents within pulsed power systems. One type provides an IR voltage output that is proportional to the measured current; another, called a Rogowski coil, requires an external integrator in order to provide a proportional output.
Ratio[edit]
The CT is typically described by its current ratio from primary to secondary. A 1000:5 CT will provide an output current of 5 amperes when 1000 amperes are flowing through its primary winding. Standard secondary current ratings are 5 amperes or 1 ampere, compatible with standard measuring instruments. It is used to step down current for metering purposes for the safety of the equipments as well as operator.
Burden and accuracy[edit]
Burden and accuracy are usually stated as a combined parameter due to being dependent on each other.
- Metering style CTs are designed with smaller cores and VA capacities. This causes metering CTs to saturate at lower secondary voltages saving sensitive connected metering devices from damaging large fault currents in the event of a primary electrical fault. A CT with a rating of 0.3B0.6 would indicate with up to 0.6 ohms of secondary burden the secondary current will be within a 0.3 percent error parallelogram on an accuracy diagram incorporating both phase angle and ratio errors.[2]
- Relaying CTs used for protective circuits are designed with larger cores and higher VA capacities to ensure secondary measuring devices have true representations with massive grid fault currents on primary circuits. A CT with a rating of 2.5L400 would indicate it can produce a secondary voltage to 400 volts with a secondary current of 100 amperes (20 times its rated 5 ampere rating) and still be within 2.5 amperes of true accuracy.
Care must be taken that the secondary winding of a CT is not disconnected from its low-impedance load while current flows in the primary, as this may produce a dangerously high voltage across the open secondary (especially in a relaying type CT) and could permanently affect the accuracy of the transformer.
Multi-ratio CT[edit]
The secondary winding can be single ratio or have several tap points to provide a range of ratios.
Voltage transformer or potential transformer[edit]
A 120:120 instrument isolation transformer showing two polarity marking conventions
Voltage transformers (VT), also called potential transformers (PT), are a parallel connected type of instrument transformer. They are designed to present negligible load to the supply being measured and have an accurate voltage ratio and phase relationship to enable accurate secondary connected metering.
Ratio[edit]
The PT is typically described by its voltage ratio from primary to secondary. A 600:120 PT will provide an output voltage of 120 volts when 600 volts are impressed across its primary winding. Standard secondary voltage ratings are 120 volts and 70 volts, compatible with standard measuring instruments.
Burden and accuracy[edit]
Transformer 2 05 01
Burden and accuracy are usually stated as a combined parameter due to being dependent on each other.
- Metering style PTs are designed with smaller cores and VA capacities than power transformers. This causes metering PTs to saturate at lower secondary voltage outputs saving sensitive connected metering devices from damaging large voltage spikes found in grid disturbances. A small PT (see nameplate in photo) with a rating of 0.3W, 0.6X would indicate with up to W load (12.5 watts[3] ) of secondary burden the secondary current will be within a 0.3 percent error parallelogram on an accuracy diagram incorporating both phase angle and ratio errors. The same technique applies for the X load (25 watts) rating except inside a 0.6% accuracy parallelogram.[4]
Markings[edit]
Some transformer winding primary (usually high-voltage) connecting wires are of many types. may be labeled as H1, H2 (sometimes H0 if it is internally designed to be grounded) and X1, X2 and sometimes an X3 tap may be present. Sometimes a second isolated winding (Y1, Y2, Y3) (and third (Z1, Z2, Z3) may also be available on the same voltage transformer. The primary may be connected phase to ground or phase to phase. The secondary is usually grounded on one terminal to avoid capacitive induction from damaging low-voltage equipment and for human safety.
Types of PTs[edit]
Simplified circuit diagram of a CVT
There are three primary types of potential transformers (PT): electromagnetic, capacitor, and optical. The electromagnetic potential transformer is a wire-wound transformer. The capacitor voltage transformer (CVT) uses a capacitance potential divider and is used at higher voltages due to a lower cost than an electromagnetic PT. An optical voltage transformer exploits the Faraday effect, rotating polarized light, in optical materials.[5]
References[edit]
Transformer 2005
- ^'Measurement Canada Standard Dwg. No.3400 D3 Delta Connected CTs'(PDF). MEASUREMENT CANADA. Retrieved 12 December 2012.
- ^'Limits of the 0.3 and 0.6 accuracy classes for measuring current transformers'. Measurement Canada. Retrieved 18 April 2013.
- ^'PS-E-15 — Provisional Specifications for Approval of Electronic Voltage Transformers'. Measurement Canada. Retrieved 18 April 2013.
- ^'PS-E-15 — Provisional Specifications for Approval of Electronic Voltage Transformers'. Measurement Canada. Retrieved 18 April 2013.
- ^Network Protection & Automation anshu, AREVA 2002
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