565:
67:
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 ) 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.
31:
219:
The tuning of the divider to the line frequency makes the overall division ratio less sensitive to changes in the burden of the connected metering or protection devices. The device has at least four terminals: a terminal for connection to the high voltage signal, a ground terminal, and two secondary
57:
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
66:
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
123:) 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.
198:
49:. They are designed to present a negligible load to the supply being measured and have an accurate voltage ratio and phase relationship to enable accurate secondary connected metering.
239:, this reduces the required insulation level of the voltage transformer. This makes CVTs more economical than the wound voltage transformers under high voltage (over 100
383:
246:
In communication systems, CVTs in combination with wave traps are used for filtering high-frequency communication signals from power frequency. This forms a
216:
to tune the device to the line frequency, and a voltage transformer to isolate and further step down the voltage for metering devices or protective relay.
679:
659:
194:
signal to the actual VT (voltage transformer) used for operating metering/protective relays due to a lower cost than an electromagnetic PT.
432:
527:
376:
352:
331:
247:
817:
699:
549:
369:
608:
477:
613:
497:
442:
437:
227:
is often constructed as a stack of smaller capacitors connected in series. This provides a large voltage drop across C
586:
564:
591:
75:
Transformer winding primary (usually high-voltage) connecting wires are of many types. They may be labeled as H
689:
596:
542:
664:
630:
537:
46:
131:
There are three primary types of potential transformers (PT): electromagnetic, capacitor, and optical.
647:
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603:
492:
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289:
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149:
776:
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635:
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452:
17:
786:
704:
674:
669:
652:
507:
487:
457:
187:
573:
472:
348:
327:
771:
581:
532:
512:
502:
209:
166:
169:
to reduce the line voltage before applying it to an ordinary electromagnetic transformer.
740:
735:
725:
447:
427:
412:
30:
290:"PS-E-15 — Provisional Specifications for Approval of Electronic Voltage Transformers"
268:"PS-E-15 — Provisional Specifications for Approval of Electronic Voltage Transformers"
811:
750:
183:
554:
34:
A 120:120 instrument isolation transformer showing two polarity marking conventions
720:
522:
462:
392:
191:
179:
745:
730:
422:
206:
781:
467:
250:
throughout the transmission network, to communicate between substations.
213:
791:
517:
361:
220:
terminals which connect to the instrumentation or protective relay.
407:
205:
In its most basic form, the device consists of three parts: a two
29:
796:
365:
766:
201:
The circuit diagram for a simple capacitor voltage transformer
197:
243:
kV), as the latter one requires more winding and materials.
99:
tap may be present. Sometimes a second isolated winding (Y
324:
Protection of industrial power systems second edition
759:
713:
572:
400:
87:if it is internally designed to be grounded) and X
152:, rotating polarized light, in optical materials.
377:
235:. As the majority of the voltage drop is on C
8:
231:and a relatively small voltage drop across C
178:A capacitor voltage transformer (CVT), is a
384:
370:
362:
311:Network Protection & Automation anshu
680:Rotary variable differential transformer
660:Linear variable differential transformer
196:
259:
212:across which the transmission line, an
137:electromagnetic potential transformer
7:
433:Condition monitoring of transformers
343:Stanley H. Horowitz, Arun G. Phadke
528:Toroidal inductors and transformers
345:Power system relaying third edition
45:, are a parallel-connected type of
18:Coupling capacitor potential device
25:
563:
700:Variable-frequency transformer
550:Transformer utilization factor
326:, Butterworth-Heinemann, 1996
163:capacitive voltage transformer
27:Type of electrical transformer
1:
248:carrier communication network
174:capacitor voltage transformer
159:capacitor voltage transformer
127:Types of voltage transformers
609:Energy efficient transformer
347:, John Wiley and Sons, 2008
139:is a wire-wound transformer.
614:Amorphous metal transformer
498:Resonant inductive coupling
438:Electrical insulation paper
146:optical voltage transformer
43:potential transformers (PT)
834:
561:
39:Voltage transformers (VT)
592:Distribution transformer
690:Solid-state transformer
597:Pad-mounted transformer
543:Transformer oil testing
58:measuring instruments.
665:Parametric transformer
631:Instrument transformer
587:Buck–boost transformer
538:Dissolved gas analysis
202:
190:signals and provide a
47:instrument transformer
35:
818:Electric transformers
648:Isolation transformer
626:Grounding transformer
604:Delta-wye transformer
483:Pressure relief valve
200:
33:
292:. Measurement Canada
270:. Measurement Canada
777:Mitsubishi Electric
695:Trigger transformer
685:Scott-T transformer
641:Voltage transformer
636:Current transformer
621:Flyback transformer
453:Induction regulator
62:Burden and accuracy
787:Schneider Electric
705:Zigzag transformer
675:Rotary transformer
670:Planar transformer
653:Austin transformer
508:Short-circuit test
488:Quadrature booster
458:Leakage inductance
203:
188:extra high voltage
165:uses a capacitive
95:and sometimes an X
36:
805:
804:
473:Open-circuit test
214:inductive element
94:
16:(Redirected from
825:
772:General Electric
567:
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822:
808:
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755:
709:
582:Autotransformer
568:
559:
533:Transformer oil
513:Stacking factor
503:Severity factor
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210:voltage divider
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167:voltage divider
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111:) (and third (Z
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748:
743:
741:Repeating coil
738:
736:Polyphase coil
733:
728:
726:Induction coil
723:
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448:High-leg delta
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428:Circle diagram
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413:Buchholz relay
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150:Faraday effect
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41:, also called
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10:
9:
6:
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2:
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815:
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760:Manufacturers
758:
752:
751:Trembler coil
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734:
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353:0-470-05712-2
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332:0-7506-2662-3
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186:to step down
185:
184:power systems
181:
173:
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164:
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156:
155:
151:
148:exploits the
147:
143:
142:
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134:
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126:
124:
70:
68:
61:
59:
52:
50:
48:
44:
40:
32:
19:
640:
555:Vector group
344:
339:
323:
318:
313:, AREVA 2002
310:
306:
294:. Retrieved
284:
272:. Retrieved
262:
245:
222:
218:
204:
177:
162:
158:
145:
136:
130:
83:(sometimes H
74:
65:
56:
42:
38:
37:
721:Hybrid coil
523:Tap changer
463:Magnet wire
393:Transformer
355:pages 64–65
223:Capacitor C
192:low voltage
180:transformer
746:Tesla coil
731:Oudin coil
423:Center tap
322:T. Davies
254:References
207:capacitor
812:Category
782:ProlecGE
493:Resolver
478:Polarity
468:Metadyne
296:18 April
274:18 April
182:used in
71:Markings
792:Siemens
518:Synchro
443:Growler
418:Bushing
334:page 55
401:Topics
395:topics
351:
330:
241:
714:Coils
574:Types
408:Balun
161:, or
53:Ratio
797:TBEA
349:ISBN
328:ISBN
298:2013
276:2013
767:ABB
144:An
135:An
119:, Z
115:, Z
107:, Y
103:, Y
91:, X
79:, H
814::
157:A
385:e
378:t
371:v
300:.
278:.
237:1
233:2
229:1
225:1
121:3
117:2
113:1
109:3
105:2
101:1
97:3
93:2
89:1
85:0
81:2
77:1
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
