Which type of connection is used in distribution transformer?

Which type of connection is used in distribution transformer?
by

1 Answer

Answer :

Distribution transformers are connected in delta-star. This arrangement requires 3 conductors in the high voltage side and 4 in the low voltage side, as well as it provides the star point conductor as a neutral point. This can serve single phase as well as three phase loads.
by

Related questions

What will happen if transformer in parallel connection have different phase sequence ?

Description : What will happen if transformer in parallel connection have different phase sequence ?

Last Answer : If the phase sequence is in an incorrect manner, in every cycle each pair of phases will get short-circuited.

What will happen if transformer in parallel connection have different percentage impedance or X/R ratio ?

Description : What will happen if transformer in parallel connection have different percentage impedance or X/R ratio ?

Last Answer : A difference in the ratio of the reactance value to resistance value of the per unit impedance results in a different phase angle of the currents carried by the two paralleled transformers; one ... of the combined output. Hence, the real power will not be proportionally shared by the transformers.

What will happen if transformer in parallel connection have different voltage ratio?

Description : What will happen if transformer in parallel connection have different voltage ratio?

Last Answer : Two transformers in Parallel should have the same primary and secondary voltage ratings. Any error in the voltage ratio would cause heavy circulating currents to flow between the transformers. ... in overloading of one transformer. This circulating current will result in increased copper losses.

What will happen if transformer in parallel connection have opposite polarity?

Description : What will happen if transformer in parallel connection have opposite polarity?

Last Answer : Connecting transformers with wrong polarity can result in circulating currents or short circuits

At what power maximum efficiency of power transformer and distribution transformer is designed

Description : At what power maximum efficiency of power transformer and distribution transformer is designed

Last Answer : Maximum efficiency of the transformer is attained at certain load factor (α) when core losses of transformer is equal to the copper losses. PCore loss = α ^2 X PCopper loss From the ... the day. Hence distribution transformers are designed to have maximum efficiency at 50% of the rated full load

What is the vector group of distribution transformer?

Description : What is the vector group of distribution transformer?

Last Answer : Dy11

Why is an auto-transformer not used as a distribution transformer?

Description : Why is an auto-transformer not used as a distribution transformer?

Last Answer : The autotransformer cannot provide isolation between HV and LV side. Due to open circuit in the common portion, the voltage on the load side may shoot up to dangerously high voltage ... voltage on LV side is potentially dangerous. Hence the autotransformer cannot be used as distribution transformer

What are the salient features of distribution transformer?

Description : What are the salient features of distribution transformer?

Last Answer : 1. The distribution transformer will have low iron loss and higher value of copper loss 2. The capacity of transformers will be up to 500 KVA 3. The transformers will have plain walled ... with cooling tubes or radiators. 4. The leakage reactance and regulation will be low.

Why the efficiency of distribution transformer is 60 to 70 % and not 100%?

Description : Why the efficiency of distribution transformer is 60 to 70 % and not 100%?

Last Answer : Distribution transformer is designed for maximum efficiency at 60% to 70% load as it normally doesn't operate at full load all the time. Its load depends on distribution demand. Whereas power transformer ... efficiency at 100% load as it always runs at 100% load being near to generating station.

What are distribution transformer?

Description : What are distribution transformer?

Last Answer : The distribution transformer is used for the distribution of electrical energy at low voltage as less than 33KV in industrial purpose and 440v-220v in domestic purpose. It works at low efficiency at 60-70%, small size, easy in installation, having low magnetic losses & it is not always fully loaded.

To protect the power transformer (Y-Y with neutral grounded) against fault, what type of connection do the CTs have ?

Description : To protect the power transformer (Y-Y with neutral grounded) against fault, what type of connection do the CTs have ?

Last Answer : To protect the power transformer (Y-Y with neutral grounded) against fault, what type of connection do the CTs have ? Δ-Δ connection

Which of the following 3-phase connection of a transformer causes interference with the

Description : Which of the following 3-phase connection of a transformer causes interference with the neighbouring communication lines:  (A) Delta-Star (B) Star-Delta (C) Delta-Delta (D) Star-Star

Last Answer : Which of the following 3-phase connection of a transformer causes interference with the neighbouring communication lines: Star-Star

Write selection criteria of distribution transformer with any four points.

Description : Write selection criteria of distribution transformer with any four points.

Last Answer : Selection Criteria for Distribution Transformer:  i) Ratings - The kVA ratings should comply with IS:2026 ( Part l )-1977*. The noload secondary voltage should be 433 volts for transformers to be ... is not necessary. vi) Cooling - The transformers covered in this group are generally ONAN, AN

The maximum efficiency of a distribution transformer is?

Last Answer : The maximum efficiency of a distribution transformer is at 50% full load.

In a power or distribution transformer about 10 percent end turns are heavily insulated?

Last Answer : In a power or distribution transformer about 10 percent end turns are heavily insulated to withstand the high voltage drop due to line surge produced by the shunting capacitance of the end turns.

What is oil immersed type transformer?

Description : What is oil immersed type transformer?

Last Answer : In this type of transformer, oil is used as coolant. Entire assembly including core and windings is kept immersed in oil. The developed heat is transferred to the walls of tank through oil. Finally the heat is transferred to the surrounding air from tank wall by radiation.

What are dry type transformer ?

Description : What are dry type transformer ?

Last Answer : In this type of transformer, air is used as coolant.The heat is taken to walls of tank and dissipated to the surrounding air.

Where is core type and shell type construction suitable for a transformer?

Description : Where is core type and shell type construction suitable for a transformer?

Last Answer : Core type transformers are popular in High voltage applications like Distribution transformers, Power transformers, and obviously auto transformers. Where as, Shell type transformers are ... voltage applications like transformers used in electronic circuits and power electronic converters etc

What are the advantages of shell type transformer over core type transformers?

Description : What are the advantages of shell type transformer over core type transformers?

Last Answer : In shell type transformers the coils are well supported on the all sides and so they can withstand higher mechanical stresses developed during short circuit conditions. Also the leakage reactance will be less in shell type transformers.

What advantage has the star connection over the delta connection ?

Description : What advantage has the star connection over the delta connection ?

Last Answer : A. Each star connection transformer is wound for only 57.7% of line voltage . In hv transmission, this admits of much smaller transformer being built for high voltage than possible with delta connection, because of less insulation.

What is the advantage is obtained in the delta connection ?

Description : What is the advantage is obtained in the delta connection ?

Last Answer : A. When three transformer are obtained in delta, one may be removed and two remaining unit will carry 57.7% of the original three phase load and thus maintain the continuity of supply.

What are the transformer losses?

Description : What are the transformer losses?

Last Answer : Answer: TRANSFORMER LOSSES - There are mainly two kinds of losses in a transformer namely 1. Copper loss (ohmic loss) and 2.magnetic loss (core loss). Copper losses are caused by the ... ohmic loss the following two losses are also present in the transformer stray load loss and dielectric loss.

What happen when Transformer is given DC supply ?

Description : What happen when Transformer is given DC supply ?

Last Answer : When DC supply is given to the transformer primary winding no back emf is induced in the transformer. Importance of Back emf is that it limits the current drawn by the machine. In the absence ... in burning down of primary winding. So when dc supply is given to transformer primary windings will burn

During No load why the power factor of the transformer is very low ?

Description : During No load why the power factor of the transformer is very low ?

Last Answer : Current flowing through the transformer consists of two components. Magnetizing current (Im) which is in quadrature (90 0 ) to the applied voltage and in phase current which is in phase to the applied voltage ... power factor of transformer during no load condition will by in the order of 0.1 to 0.2

What is the supply rated o/p if two single phase transformer connect to give three phase o/p from a three phase I/p?

Description : What is the supply rated o/p if two single phase transformer connect to give three phase o/p from a three phase I/p?

Last Answer : A. Each transformer is only capable of supplying 86.6%of its o/p rating

How to connect two single phase transformer to give three phase o/p from a three phase I/p ?

Description : How to connect two single phase transformer to give three phase o/p from a three phase I/p ?

Last Answer : A. They would have to connect in an open-delta.

What is the 3 ph transformer ?

Description : What is the 3 ph transformer ?

Last Answer : A. A 3ph transformer is that transformer which is equivalent to three single phase transformer but wound on one core and enclosed within one common case.

What parameters or technical particulars are important to be considered while designing protection scheme of the transformer?

Description : What parameters or technical particulars are important to be considered while designing protection scheme of the transformer?

Last Answer : 1.Network Diagram showing the position of the transformer in the system 2.kVA or MVA rating of the transformer 3.Fault Level at the transformer 4.Voltage Ratio 5.Winding Connections 6.Per Unit ... Oil Filled 11.Length and area of cross section of the connecting leads between CTs and Relay Panel

What can be the reasons for the failure of the transformer?

Description : What can be the reasons for the failure of the transformer?

Last Answer : Answer: Transformer is one of the most expensive equipments in the Power System. Failure of the transformer can cause outage of power supply for even days. However, multiple things can go wrong with ... relays. 3.Short Circuits 4.Open Circuits 5.Earth Faults 6.Over Voltage 7.Reduced system frequency

How Transformer Protection provided for internal faults?

Description : How Transformer Protection provided for internal faults?

Last Answer : 1.Bucholz Relay (1st Stage Alarm and 2nd Stage Trip) 2.Sudden Pressure Relay (1st Stage Alarm and 2nd Stage Trip) 3.Pressure Relief Valve (1st Stage Alarm and 2nd Stage Trip) 4.Pressure Switch ... 8.Gas Temperature Indicator (Alarm) 9.Silicon Breather (Passive - no alarm) 10.Smoke Detector (Alarm)

How does change in frequency affect the operation of a given transformer?

Description : How does change in frequency affect the operation of a given transformer?

Last Answer : a) Iron loss .........increases with a decrease in frequency. A 60-Hz transformer will have nearly 11% higher losses when worked on 50Hz instead of 60 Hz. However, when a 25-Hz ... ....since total loss is greater at a lower frequency, the temperature is increased with decrease in frequency.

Does the transformer draw any current when its secondary is open?

Description : Does the transformer draw any current when its secondary is open?

Last Answer : Yes, no-load primary current.

WHAT is ZIG ZAG Grounding Transformer

Description : WHAT is ZIG ZAG Grounding Transformer

Last Answer : ANSWER: Three Single Phase Transformers can be connected to have a three phase Zig Zag Transformer. This system can be used for either grounding or developing a fourth WIRE from a three phase neutral. An example ... - three phase - three wire system to a 480Y/277 V - three phase - four wire system

What is Meant by Temperature Rise in a Transformer?

Description : What is Meant by Temperature Rise in a Transformer?

Last Answer : ANSWER: Temperature rise in a transformer is the temper¬ature of the windings and insulation above the existing ambi¬ent or surrounding temperature, and is determined by the insulation class used in the transformer coils.

What is Meant by Regulation in a Transformer?

Description : What is Meant by Regulation in a Transformer?

Last Answer : ANSWER: Voltage regulation in transformers is the difference between the no load voltage and the full load voltage. This is usually expressed in terms of percentage. For example: A transformer delivers 100 ... from 2% to 4%, depending on the size and the application for which they are used

What is Polarity, When Associated With a Transformer?

Description : What is Polarity, When Associated With a Transformer?

Last Answer : A: Polarity is the instantaneous voltage obtained from the primary winding in relation to the secondary winding. Transformers 600 volts and below are normally connected in additive polarity - that ... parallel for three phase operations. Polarity is a term used only with single phase transformers

During No load why the power factor of the transformer is very low ?

Description : During No load why the power factor of the transformer is very low ?

Last Answer : A. Current flowing through the transformer consists of two components. Magnetizing current (Im) which is in quadrature (900) to the applied voltage and in phase current which is in phase to the applied voltage ... factor of transformer during no load condition will by in the order of 0.1 to 0.2

Explain about auto transformer?

Description : Explain about auto transformer?

Last Answer : A. It is type of transformer with only one winding a portion of which is shared by both primary and secondary. Advantages: It is used where transformation ratio differs little from unity. As ... voltage as per out requirements and can smoothly increase or decrease its value as per our requirement.

Explain about the open and short circuit tests on transformer?

Description : Explain about the open and short circuit tests on transformer?

Last Answer : A. Open circuit test (No load test) and short circuit test (full load test) are performed on a transformer to determine (i) Equivalent circuit of transformer (ii) Voltage ... determine copper loss in transformer at full load and parameters of approximate equivalent circuit of transformer.

EMF equation of the transformer?

Description : EMF equation of the transformer?

Last Answer : A. E = 4.44ΦmfN Volts. If E1 & E2 are primary and secondary emf’s and N1 & N2 are primary and secondary turns then, Voltage ratio= E1/E2 and Turns ratio of transformer = N1/N2 E1/E2 = N1/N2

What is tertiary winding? What is Three Winding Transformer? What are its advantages?

Description : What is tertiary winding? What is Three Winding Transformer? What are its advantages?

Last Answer : A. In some high rating transformers, one winding, in addition to the primary and secondary winding, is used. This is known as Tertiary Winding of Transformer. Because of this third winding, the ... it assists in limitation of fault current in the event of a short circuit from line to neutral.

What is polarity, when associated with a transformer?

Description : What is polarity, when associated with a transformer?

Last Answer : A. Polarity is the instantaneous voltage obtained from the primary winding in relation to the secondary winding. Transformers 600 volts and below are normally connected in additive polarity - that ... parallel for three phase operations. Polarity is a term used only with single phase transformers.

Can a Single Phase Transformer be used on a Three Phase source?

Description : Can a Single Phase Transformer be used on a Three Phase source?

Last Answer : A. Any single phase transformer can be used on a three phase source by connecting the primary leads to any two wires of a three phase system, regardless of whether the source is three phase 3-wire or three phase 4 wire. The transformer output will be single phase.

What is meant by regulation in a transformer?

Description : What is meant by regulation in a transformer?

Last Answer : A. Voltage regulation in transformers is the difference between the no load voltage and the full load voltage. This is usually expressed in terms of percentage. Example: A Transformer delivers 100 ... The regulation capacity varies depending on the size and the application for which they are used.

What will happen if DC supply is given on the primary of a transformer?

Description : What will happen if DC supply is given on the primary of a transformer?

Last Answer : A. Mainly transformer has high inductance and low resistance. In case of DC supply there is no inductance, only resistance will act in the electrical circuit. So, high electrical current will flow through primary side of the transformer. Due to this the coil and insulation will burn out.

Explain the operation of variable frequency transformer?

Description : Explain the operation of variable frequency transformer?

Last Answer : A. A variable frequency transformer is used to transmit electricity between two asynchronous alternating current domains. It is a double fed electric machine resembling a vertical shaft hydroelectric ... adjustable phase shifting transformer. It allows control of the power flow between two networks.

What is voltage ratio of a transformer?

Description : What is voltage ratio of a transformer?

Last Answer : A. Voltage ratio is the ratio of the voltage between the line terminals of one winding to that between the line terminals of another winding at no load.

If we give 2334 A, 540V on Primary side of 1.125 MVA step up transformer, then what will be the Secondary Current, If Secondary Voltage=11 KV?

Description : If we give 2334 A, 540V on Primary side of 1.125 MVA step up transformer, then what will be the Secondary Current, If Secondary Voltage=11 KV?

Last Answer : A. As we know the Voltage & current relation for transformer-V1/V2 = I2/I1 We Know, VI= 540 V; V2=11KV or 11000 V; I1= 2334 Amps. By putting these value on Relation540/11000= I2/2334 So,I2 = 114.5 Amps

What is the function of transformer oil?

Description : What is the function of transformer oil?

Last Answer : A. Transformer Oil serves mainly two purposes 1. It acts as liquid insulation in electrical power transformer 2. It dissipates heat of the transformer i.e acts as coolant. In addition to these ... acid (C7, C8) esters are also becoming increasingly common as alternatives to naphthenic mineral oil.

What is the difference between delta-delta, delta-star transformer?

Description : What is the difference between delta-delta, delta-star transformer?

Last Answer : A. Delta-delta transformer is used at generating station or a receiving station for Change of Voltage (i,e) generally it is used where the Voltage is high & Current is low whereas Delta-star ... star neutral is taken as a return path and this configuration is used for Step down voltage phenomena.