Explain the electrical characteristics of transformer.

1 Answer

Answer :

Transformer electrical characteristics:

Area of primary and secondary conductors, Apri and Asec:

Winding loss Pw:

Flux density and core loss:

Leakage inductance:

Rated power:

Load losses:

Rated voltage:

Frequency:

Noise:

Short circuit current:

No load current:



Effect of a rise in temperature on transformer:

High-efficiency transformer has a low rise in temperature while low-efficiency transformer has high rise in temperature. Temperature rise affects the transformer span. The rise in temperature may breakdown insulation which may cause failure of the transformer.

Related questions

Description : Draw a symbol and neat labeling V-I characteristics of GTO and explain its operation.

Last Answer : Ans: Symbol and V-I characteristics of GTO: Operation of GTO: i) As the applied anode to cathode voltage is increased above zero, very small current (leakage current) flows through the device. ... low voltage (VBRR). The reverse breakdown voltage is of the order of 20 to 30 volt only. 

Description : Draw a neat labelling V-I characteristics of SCR and explain the region

Last Answer : (i) Latching current: It is the minimum anode current required to maintain the SCR in the conduction state just after turn-on and the gate signal has been removed.  (ii) Holding current: It is the minimum anode current required to hold the conducting SCR in the ON state. 

Description : Draw symbol & V-I characteristics of (i) LASCR (ii) DIAC (iii) TRIAC

Last Answer : (i) LASCR:  (ii) DIAC:  (iii) TRIAC: 

Description : What are the desirable characteristics of ideal switch?

Last Answer : Desirable characteristics of the ideal switch: It is desirable to have power switches characteristics closer to ideal switch. The ideal switch should have the following characteristics. Zero resistance when ... . 100% efficiency. Able to control power flow with zero power dissipation.

Last Answer : The efficiency of transformer is Greater than electrical Machine because there is no rotational losses in transformer and there is no air gap losses in transformer so losses is less in transformer compare to electrical machine so efficiency is higher in case of transformer.

Description : Draw the structural diagram of GTO. Explain briefly the switching behavior of GTO with the help of appropriate voltage and current waveform.

Last Answer : Gate Turn Off Thyristor (GTO) Conventional Thyristor can be turned on with gate terminal but can not turn off from gate terminal. But in case of Gate Turn Off Thyristor (GTO), we can turn it on and off ... subdivided as storage period (Ts), fall period (Tp) and tail period (Tt).

Description : Explain the characteristics of solar cell.  

Last Answer : Characteristics of solar cell : Explanation :- Solar cells produce direct current ( DC ) electricity and current times voltage equals power, so we can create solar cell I-V curves representing ... system so that it can operate as close to its optimal peak power point (MPP) as possible.

Description : Diode VI characteristics

Last Answer : Diode VI characteristics

Description :  basic characteristics of sound signal.

Last Answer : Level and loudness: The amplitude of a sound wave determines its loudness or volume. A larger amplitude means a louder sound, and a smaller amplitude means a softer sound. The loudness of a ... the reproducing system should be capable of handling the maximum and minimum power in the same ratio. 

Description : Compare characteristics of asynchronous and synchronous transmission mode (four points). 

Last Answer : Synchronous transmission Asynchronous transmission 1. Synchronous transmission are synchronized by an external clock. 1. Asynchronous transmission are synchronized by special signals along the transmission ... for transferring a small amount of data as it is simple and economical.

Description : State characteristics of force.

Last Answer : i) Magnitude: The quantity of force e.g. 10 N, 100 kN etc.  ii) Direction: It is the line along which the force acts. It is also called as line of action of the force.  iii) Point of ... .  Push: If the arrow head is pointed towards the point of application, the nature of the force is push.

Description : What is the smallest unit of a compound with the same chemical characteristics?

Last Answer : The molecule is the smallest unit of a compound with the same chemical characteristics.

Description : The following is/are the characteristics of SF6 circuit breakers:  (A) It does not need an auxiliary breaking chamber (B) Short break time of 2 to 2.5 cycles (C) All of the above (D) None of the above

Last Answer : The following is/are the characteristics of SF6 circuit breakers:  (A) It does not need an auxiliary breaking chamber (B) Short break time of 2 to 2.5 cycles (C) All of the above (D) None of the above

Description : The terminal characteristics of a dc generator suitable for electric welders is (A) separately excited generator (B) shunt generator (C) series generator (D) differentially compounded generator

Last Answer : The terminal characteristics of a dc generator suitable for electric welders is differentially compounded generator

Description : Which of the following does not show non-linear V-I characteristics? (A) Schottky diode (B) Tunnel diode (C) Thermistor, at a fixed temperature (D) p-n Junction diode.

Last Answer : Which of the following does not show non-linear V-I characteristics? (A) Schottky diode (B) Tunnel diode (C) Thermistor, at a fixed temperature (D) p-n Junction diode.

Last Answer : The desirable static characteristics of a measuring system are accuracy, sensitivity and reproducibility.

Last Answer : The speed/load characteristics of a universal motor is same as that of D.C. series motor.

Description : Explain the single pass transformer design procedure step by step by giving its flowchart.

Last Answer : single pass transformer design procedure step by step by giving its flowchart:

Description : What are the design constraints of transformer design?

Last Answer : Design constraints of transformer design: Core loss, flux density, copper loss and total power loss vs flux density these are the basic constraints in transformer design. Core loss: Flux density: Copper loss: Total power loss vs flux density:

Description : Can transformer convert AC to DC?

Last Answer : No, Transformer cannot convert AC to DC.

Description : State any four characteristics of core type transformer.

Last Answer : Characteristics of core type transformer: i) It has one window. ii) It has one magnetic circuit. iii) Core surrounds the winding. iv) Average length of core is more. v) Area of cross ... Better cooling for winding. vii) Mechnical strength is comparatively less. viii) Repair and maintenance is easy.

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.

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.

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.

Description : Explain about the losses in Transformer?

Last Answer : TRANSFORMER LOSSES - Transformer losses have two sourcescopper loss and magnetic loss. Copper losses are caused by the resistance of the wire (I2R). Magnetic losses are caused by eddy currents ... current. Eddy-current loss, however, is different for each frequency passed through the transformer.

Description : Explain the working principle of Transformer?

Last Answer : A. Working principle of Transformer is based on Faraday's Laws of Electromagnetic Induction. If an alternating current is applied to an electric coil, there will be an alternating flux surrounding ... second coil. Therefore emf will be induced in it as per Faraday's laws electromagnetic induction.

Description : Explain the effect of Harmonics on the Transformer.

Last Answer : Effect of Harmonics on the Transformer:  1. Core loss: Harmonic voltage increases the hysteresis and eddy current losses in the lamination. The amount of the core loss depends on ... small core vibrations.  5. Saturation problem: Sometimes additional harmonic voltage causes core saturation.

Description : Explain construction and working of single phase Auto transformer.

Last Answer : Construction of single phase auto transformer: (i) It has only one winding wound on a laminated circular magnetic core. (ii) The core is made of silicon steel stampings. (iii) The two terminals of the ... help of handle. 5) The same transformer can be used as step-up or step down auto-transformer

Description : Explain construction and working principle of single phase transformer.

Last Answer : A single phase transformers is an electrical device that accepts single-phase AC power and outputs single-phase AC. PRINCIPLE... The single-phase transformer works on the principle of ... and secondary windings. Thin steel laminations shall be employed to prevent power losses from the core.

Description : Explain any four advantages of amorphous transformer.

Last Answer : Advantages of amorphous core transformer: 1) Lowest hysteresis loss. 2) Low eddy current loss. 3) Low temperature rise. 4) Up to 75% energy saving using amorphous metal than conventional metal. 5 ... capacity. 9) High Reliability. 10) Excellent short circuit capacity. 11) Less maintenance cost. 

Description : Explain construction and working of isolation transformer.

Last Answer :  Isolation Transformer https://youtu.be/gq9kjLlhPN0

Description : What is a Transformer ?

Last Answer : Ans : A transformer is a static piece of apparatus which transforms electrical energy from one Circuit to another circuit without changing the frequency either stepping up or stepping down the voltage .

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.

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

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

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

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

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.

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.

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

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

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)

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.

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

Last Answer : Yes, no-load primary current.

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

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.

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

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

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