# Harmonics in transformer result in?

Harmonics in transformer result in increased core losses, increased I2R losses, and magnetic interference with communication circuits.

## Related questions

Answer : The main reason for generation of harmonics in a transformer could be saturation of core.

Description : Explain the effect of Harmonics on the Transformer.

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 : Slot harmonics are reduced in induction motors by using (A) fractional-pitch windings (B) fractional-slot windings (C) integral-slot windings (D) distributed windings

Answer : Slot harmonics are reduced in induction motors by using fractional-slot windings

Description : State the need for reduction of harmonics in inverters. Enlist the various methods for reduction of harmonics in inverter output.

Description : Why harmonics are generated in electrical system?

Description : What is mitigation of harmonics?

Description : What is current harmonics?

Description : What are even and odd harmonics?

Description : What are the main causes of harmonics?

Answer : Harmonic is a non linear load because linear load voltage deviated due to connection of some electrinie device such as converter,inverter

Description : Why do non linear loads cause harmonics?

Description : Two transformers are connected in parallel. These transformers do not have equal percentage impedance. This is likely to result in?

Answer : Two transformers are connected in parallel. These transformers do not have equal percentage impedance. This is likely to result in loading of the transformers not in proportion to their kVA ratings.

Answer : A common method of cooling a power transformer is oil cooling.

Answer : Winding will be damaged

Description : If the percentage impedances of the two transformers working in parallel are different, then?

Answer : If the percentage impedances of the two transformers working in parallel are different, then parallel operation will still be possible, but the power factors at which the two transformers operate will be different from the power factor of the common load.

Description : Losses which occur in rotating electric machines and do not occur in transformers are?

Answer : Friction losses windage losses

Answer : Natural oil cooling is used for transformers up to a rating of 3000 kVA.

Answer : Distribution transformers are generally designed for maximum efficiency around 50% load.

Answer : Power transformers are generally designed to have maximum efficiency around near full-load.

Answer : Short circuit test on transformers is conducted to determine copper losses.

Answer : Necessary conditions required to be satisfied in order to ensure successful parallel operation of single phase transformers:  1. Only transformers having the same phase displacement between primary and secondary ... . 7. The phase sequence must be followed strictly on HV and LV side connection.

Answer : Natural air cooling is generally restricted for transformers up to 1.5 MVA .

Description : The efficiency of two identical transformers under load conditions can be determined by?

Answer : The efficiency of two identical transformers under load conditions can be determined by back-to-back test.

Description : The efficiencies of transformers compared with that of electric motors of the same power are?

Answer : Transformers have high efficiency than the same ratted motors

Description : State any two conditions for parallel operation of 3-phase transformer.

Answer : Conditions for Parallel operation of 3 phase transformer 1) Voltage ratings of both the transformers must be identical. 2) Percentage or p.u. impedance should be equal in magnitude. 3) X/R ratio ... between primary & secondary voltages must be same. 6) Phase sequence on both sides must be same.

Description : Compare core type transformer and shell type transformer on the following parameters. (i) Types of winding used, (ii) Application

Description : Define: (i) Commercial efficiency of a transformer and  (ii) All day efficiency of a transformer.

Answer : (i) Commercial Efficiency : It is the ratio of output power in watt to the input power in watt. (ii) All day efficiency of a transformer: It is the ratio of output energy in kWh to the input energy in kWh in the 24 hours of the day

Description : A 50 KVA transformer has iron loss 2 kW on full load. Calculate its iron loss at 75% of full load.

Answer : Iron loss is dependent on voltage and independent of load. Hence iron loss at 75% of Load = Iron loss at full load = 2 kW

Description : State any four properties of Ideal transformer.

Answer : Properties of Ideal transformer: 1) No losses (iron and copper losses), hence no temperature rise. 2) No magnetic leakage i.e (Coefficient of coupling between primary and secondary windings is unity) 3) Zero winding ... drop i.e. E1 = V1, E2 = V2 5) Efficiency 100 %. 6) Regulation 0 %.

Description : Why circuit breaker connect b)w two transformer  (same rating

Answer : Because two transformers connection is in parallel to share the load if any transformer is receives the surge current because of the fault so to protect the other transformer from the fault.

Description : Define transformation ratio in terms of current and voltage.

Answer : (i) Transformation Ratio (K) is defined as the ratio of the primary current to the secondary current.  (ii) Transformation Ratio (K) is defined as the ratio of the secondary voltage to the primary voltage.

Description : In a transmission line if booster transformers are to be used, preferred location will be  (A) At the receiving end (B) At the sending end (C) At the intermediate point (D) Anywhere in the line

Answer : In a transmission line if booster transformers are to be used, preferred location will be At the intermediate point

Description : The friction losses in Real Transformers are :  (A) 0% (B) 5% (C) 25% (D) 50%

Description : Two 3-phase transformers cannot be operated in parallel, if their :  (A) kVAs are different (B) phase sequences are different (C) % impedances are different (D) voltage ratios are different

Answer : Two 3-phase transformers cannot be operated in parallel, if their : phase sequences are different

Description : Which of the following is the advantage of using CRGO steel in transformers? A) High magnetic flux density B) Low permeability C) Both A and B D) None of these

Answer : It definitely High Magnetic Flux Density since a crgo steel has always a more around 3% of silicon proportion among the remaining ferrite which make cold rolled grain oriented steel having high flux magnetic ... for more about the crgo core you can learn here https://nicoreindia.com/crgo-core/

Description : What is the back EMF in Transformers?

Answer : Current transformers (CT) : Current transformer (CT) actually step down the high current to low current for the operation of relays. Current transformer is use for measurement of ... use for relay. This is about potential transformer.

Description : State any two applications of single phase autotransformer.

Answer : Applications of single phase auto transformers: 1) Give small boost to distribution cable to correct the voltage drop. 2) As auto transformer starter for induction motors. 3) As furnace supply ... . 5) In control equipment for single phase locomotives. 6) As dimmer in lighting circuits.

Description : Draw the connection diagram of long shunt differential D.C. compound generator.

Description : Classify the transformers based on the construction, frequency and power.

Answer : Classification of Transformer Based On: i) Construction: Shell type, Core type, Berry type ii) Change in voltage level: Step-Up, Step-Down, iii) Number of phases: Single phase, Three phase iv) ... Control vi) Cooling: Self-cooled, Air-cooled, Forced-air cooled, Oil-cooled, Forced-oil cooled.

Description : Which of the following connection of transformers will give highest value of secondary voltage ? (A) Delta primary delta secondary (B) Delta primary star secondary (C) Star primary star secondary (D) Star primary delta secondary

Answer : Which of the following connection of transformers will give highest value of secondary voltage ? (A) Delta primary delta secondary (B) Delta primary star secondary (C) Star primary star secondary (D) Star primary delta secondary

Description : Two transformers A and B having equal outputs and voltage ratios but unequal percentage impedances of 4 and 2 are operating in parallel. The transformer A will be overloaded by

Answer : Two transformers A and B having equal outputs and voltage ratios but unequal percentage impedances of 4 and 2 are operating in parallel. The transformer A will be overloaded by 33%

Description : Core type transformers are popular in___________.  (A) High voltage applications (B) Low voltage applications (C) All of the above (D) None of the above

Answer : Core type transformers are popular in High voltage applications

Description : An additional condition for parallel operation of three-phase transformers over single-phase transformers is that

Answer : An additional condition for parallel operation of three-phase transformers over single-phase transformers is that the transformers should belong to the same vector group

Answer : Instrument transformers are potential transformers, current transformers.

Description : Why do transformers make noise?

Answer : Transformers make noise based on it out put if an transformer outputs is 400v maximum than a 398v be apply to that transformer it also make a noise because of that

Description : In star-star connection of 3-phase transformer, the triplen harmonics are suppressed by using (A) star connected tertiary windings (B) delta connected tertiary windings (C) neutral conductor (D) additional insulation for the phases

Answer : The short circuit in any winding of the transformer is the result of impulse voltage.

Description : Full load copper loss in a transformer is 1600 watts. At half load the copper loss will be: A) 6400 watt B) 1600 watt C) 800 watt D) 400 watt

Answer :  Full load cupper loss in a transformer is 1600 watts. At half load the cupper loss will be: 400 watt

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