One of the major difference between them is that the current transformer convert the high value of current into low value whereas the potential or voltage transformer convert the high value of voltages into low voltage. Due to the covid19 outbreak, people in ohio have been ordered to shelter in place until april 6, 2020. How is current transformer different from potential. The guiding system, the new way to create your electrical installations a comprehensive offer of products with consistent design. Current transformer s performance specifications, includes primary current, secondary current, ratio, insulation voltage, accuracy, and burden. The wire itself becomes the primary winding and the coil wrapped around the ring core will be the secondary the meter translates the output voltage to current.
A current transformer operates with a set primary current and will try to output a constant current to the load, independent of the. Bus protection l overcurrent l differential l backup l under voltage. We will know about what is basic difference between ct and pt. Transformers used for voltage potential measurement steps down the voltage to the level of voltmeter. Since the invention of th e first constantpotential transformer in 1885, transformers have become essential for the transmission, distribution, and utilization of alternating current electrical. Therefore, very cheap moderate rating instruments may be used to measure large currents and high voltages. A current transformer ct is a type of transformer that is used to measure ac current. Instrument transformer ppt free download as powerpoint presentation. A potential transformer is a conventional transformer having primary and secondary windings.
Instrument transformer basic technical information and. Ppt transformers powerpoint presentation free to view. National electrical power company instrument transformers an instrument transformer is a device used to reduce the current or voltage values into. Manufactured using highgrade material like copper, transformer oil, creep tape, insulators, toroidal corelaminationcork sheet kraft paper and steel. Current and voltage transformer symbols and simplified concepts 5 i 1 i 2 v 1 v 2 symbol of a current transformer symbol of a voltage transformer conceptual picture of a current transformer. Potential transformer or voltage transformer gets used in electrical power system for stepping down the system voltage to a safe value which can be fed to low ratings meters and relays. Current transformers pts potential transformers 5 potential transformers pts. Transformers multiple choice questions and answers mcqs electrical engineering interview transformers viva lab manual pdf free download. View potential transformer ppts online, safely and virusfree. Scribd is the worlds largest social reading and publishing site. Commercially available relays and meters used for protection and metering, are designed for low voltage. For pricing and availability of a specific ct model, give us a call at 614 8896152 or use the quote request form.
Unfortunately, we cannot detect rss feed on this website, but you may observe related news or popular pages instead. Typically current transformers consist of a silicon steel ring core wound with many. Ppt instrument transformer powerpoint presentation. The output of a constantvoltage transformer is essentially a square wave, which is desirable for rectifier output applications while, also. Solve problems involving transformer losses and demonstrate the effect they have on efficiency. In this article we will learn about the difference between ct and pt. Current transformers are constructed in various ways. This transformer step down the voltage to a safe limit value which can be easily measured by the ordinary low voltage instrument like a voltmeter, wattmeter and watthour meters, etc. This is step up transformer because when we step up, the voltage increases and current decrease.
Calculate the voltage, current, and power in a transformer. Transformers can be segmented on the basis of type as distribution transformer, power transformer and others, which includes instrument transformer. Ct, pt and cvt it help in measurement of high voltage and current. Difference between ct and pt the electrical portal. Figure 144 shows the magnetic field during one cycle. Primary current, the load of the current transformer, is the measured current. A transformer is a device used to change the voltage levels of electricity to facilitate the transfer of electricity from. Instrument transformers are also used with protective relays for protection of power system basic function of instrument transformers is to step down the ac system voltage and. The current transformer is a stepup transformer which is used to.
One method is quite similar to that of the potential transformer in that there are two separate windings on a. Potential transformer112 free download as powerpoint presentation. Types of instrument transformer instrument transformer has two type 1 current transformer 2potential transformer 5 6. This type of voltage transformer can supply several kva low voltage power directly from a high voltage transmission line. One end of the secondary winding is connected to one end of the primary. The magnetic field around the winding is constantly in motion. Instrument transformers are high accuracy class electrical devices used to isolate or transform voltage or current levels. Current transformers and voltage transformers powerpoint ppt presentation. The current transformers reduce the level of current to the instrument or relay operating range, whereas potential transformers transforms the high voltage to a circuit operating low voltage. Structure of transformer the transformer two inductive coils,these are electrical separated but linked through a common magnetic current circuit these two coils have a high mutual induction one of the two coils is connected of alternating voltage. Hv instrument transformer market 2018 by manufacturers, regions, type and application, forecast to 2023 hv instrument transformer is designed to transform high current and high voltage levels down to low current and low voltage outputs in a known and accurate proportion specified by the product nameplate ratios. Established in the year 1989, we, victrans engineers, are an eminent manufacturer and supplier of an unsurpassed assortment of current transformer 33 kv up to 220 kv and potential transformer 33 kv up to 145 kv. In principle, the only difference between a current transformer and a voltage transformer normal type is that the former is fed with a constant currentwhile the latter is fed with a constant voltage, where constant has the strict circuit theory meaning.
Bus under voltage protection armature shown in the nonenergized trip position normally open contacts to potential transformer. Unique to a current transformer the current transformer function is different than that of a voltage transformer. The constantvoltage transformer cvt has a wide application, particularly where reliability and inherent regulating ability against line voltage changes are of prime importance. Current transformer is used to measure the current flowing in a wire. Current transformer and potential transformer manufacturer. Analysis, size, share, business development and regional overview by 2023 transformers cover a very diverse subject area that encompasses both, small and very large components. It is a device used to measure large current by scaling large primary currents to a smaller, easy to measure, secondary currents. Transformers used for voltage potential measurement. Correct operation of currentcurrent, voltagevoltage, or currentvoltage devices usually depends on the relative instantaneous directions. Types of instrument transformer instrument transformer has two type 1 current transformer 2 potential transformer 5 6. It offers all the benefits of a potential transformer with the applications of a distribution transformer. Instrument transformer ppt transformer electric current scribd.
Some other differences between the current and the potential transformer are explained below in the the comparison chart. We will also learn about the current transformer and potential transformer. The burden with which the transformer is to be tested is connected across the secondary winding, and the normal primary voltage, at the normal frequency is applied to the primary winding. It produces an alternating current ac in its secondary which is proportional to the ac current in its primary. Used in ac system for the measurement of current, voltage, power and energy. 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. Instrument transformer theory and testing steve hudson, pe. Potential transformer pt definition the potential transformer may be defined as an instrument transformer used for the transformation of voltage from a higher value to the lower value. Presentation on current transformers submitted by roopal pancholi b.
This makes the replacement of instrument transformer very easy. If the load is disconnected from the secondary winding of the transformer and a high voltage is applied to the primary winding of the transformer, a magnetizing current will flow in the primary. Current transformer or ct is a type of instrument transformer that is used in power system for measurement, detection, and protection the system. Equivalent current transformer circuit x 1 primary leakage reactance r 1 primary winding resistance x 2 secondary leakage reactance z 0 magnetizing impedance r. Instrument transformers are used in ac system for measurement of electrical quantities i. Start reading the news feed of sooryaelectrocomponents right away. The figure below shows the connections for testing a potential transformer using a resistance potential divider. Tech electrical, iii year, v semester k72 submitted to mr. Current transformers ct are a series connected type of instrument transformer. The singlephase distribution transformer consists of a primary winding and a secondary winding wound on a laminated steel core.
In this article we are going to discuss in detail about the potential transformers. A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction. Voltage transformer or potential transformer theory. Show how to connect singlephase transformers to produce threephase transformers.
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