Why inter-turn protection is provided along with differential protection in generator?

Why inter-turn protection is provided along with differential protection in generator?
by

1 Answer

Answer :

Inter-turn protects two separate windings from the fault of the generator.  
by

Related questions

Why generator differential provided?

Description : Why generator differential provided? 

Last Answer : For generator phase to phase faults and 3 phase faults. 

Why main generator/UT is not provided with separate overfluxing protection?

Description : Why main generator/UT is not provided with separate overfluxing protection?

Last Answer : Since GT is provided with overfluxing protection, it is adequate to protect main generator / UT also. Main generator can withstand higher degree of overfluxing. If a generator CB is used, separate overfluxing protection is essential for main generator. 

Explain differential protection?

Description : Explain differential protection?

Last Answer : Differential protection is based on the fact that any fault within an electrical equipment would cause the current entering it, to be different, from that leaving it. Thus, we can compare the two ... phase or both and issue a trip output if the difference exceeds a pre- determined set value.

What are the problems in bus zone differential protection?

Description : What are the problems in bus zone differential protection?

Last Answer : Large number of circuits, different current levels for different circuits for external faults. Saturation of CT cores due to dc component and ac component in short circuit currents. The saturation ... the bus makes circuit complicated. Setting of relays need a change with large load changes.

What are the problems arising in differential protection in power transformer and how are they overcome?

Description : What are the problems arising in differential protection in power transformer and how are they overcome?

Last Answer : 1. Difference in lengths of pilot wires on either sides of the relay. This is overcome by connecting adjustable resistors to pilot wires to get equipotential points on the pilot wires. 2. ... harmonic restraining unit is added to the relay which will block it when the transformer is energized.

What is the coverage of differential protection for SUT?

Description : What is the coverage of differential protection for SUT?

Last Answer : Covers from 230 kV bushing to 6.6 kV breaker end.  

What is differential protection?

Description : What is differential protection? 

Last Answer : It is the current balance type protection, in which vector difference between current entering the winding is used for relay operation. 

Why differential protection for PHT motors?

Description : Why differential protection for PHT motors?

Last Answer : For more than 2500 kW motors it is required to provide differential protection. It is biased Relay against internal phase fault or earth fault very fast. Insensitive to starting current and stalling current. 

Why delta – delta CT’s are used for star – star transformer differential protection?

Description : Why delta – delta CT’s are used for star – star transformer differential protection?

Last Answer : Say primary neutral is not solidly earthed. Then for any earthfault on secondary terminal, the primary current distribution is so for external fault, the differential is likely to operate if sequence current ... into relay. The 2:1:1 distribution is possibly only for core type or delta tertiary.

An AC generator operating in parallel loses its excitation without tripping the circuit breaker. This will __________. A. not affect the faulty generator due to the compensation of the other generators B. cause the slip rings to melt C. cause a low voltage differential to develop between the armature and the bus D. cause high currents to be induced in the field windings

Description : An AC generator operating in parallel loses its excitation without tripping the circuit breaker. This will __________. A. not affect the faulty generator due to the compensation of the other generators B. ... between the armature and the bus D. cause high currents to be induced in the field windings

Last Answer : Answer: D

Will main generator differential relay pick up for generator earth faults?

Description : Will main generator differential relay pick up for generator earth faults? 

Last Answer : No earth fault current limited to 5A, while differential setting is 10%. 

Which one of the following statements for a dc machine which is provided with inter pole winding (IW) as well as compensating winding (CW) is correct a) Both IW and CW are connected in series with Armature winding b) Both IW and CW are connected in parallel with Armature winding c) IW connected in series but CW is connected in parallel with Armature winding d) CW connected in series but IW is connected in parallel with Armature winding

Description : Which one of the following statements for a dc machine which is provided with inter pole winding (IW) as well as compensating winding (CW) is correct a) Both IW and CW are connected in ... parallel with Armature winding d) CW connected in series but IW is connected in parallel with Armature winding

Last Answer : Ans: Both IW and CW are connected in series with Armature winding

Which type of protection is provided on a generator to protect against stator insulation failure?

Description : Which type of protection is provided on a generator to protect against stator insulation failure? A) Differential protection B) Overcurrent relay C) Thermocouple actuated alarm D) Reverse power relay

Last Answer : Which type of protection is provided on a generator to protect against stator insulation failure? A) Differential protection B) Overcurrent relay C) Thermocouple actuated alarm D) Reverse power relay 

Why 100% winding protection is felt essential for main generator stator E/F protection? (Used in NAPS onwards?)

Description : Why 100% winding protection is felt essential for main generator stator E/F protection? (Used in NAPS onwards?)  

Last Answer : At MAPS 4% of winding is not protected. Earlier felt that the Electro magnetic stress due high external fault currents near 4% of neutral may not be high to cause E/F here. But now felt that the mechanical stress can leads to E/F. 

How main generator protection grouped?

Description : How main generator protection grouped?

Last Answer : The various protections associated with the generator, Generator transformer and Unit transformer are connected to a trip unit through trip relays 86A, 86B and 86C. The protective levels of generator are in ... breaker. During Class C trip, the generator will come on House load mode of operation.  

What is the purpose of back up impedance protection in main generator?

Description : What is the purpose of back up impedance protection in main generator?  

Last Answer : Covers inter-phase faults both externals to the GT and in GT. This also covers partially faults inside generator, time delayed to coordinate with 230 kV-distance protection. 

Where automatic restart does not present a hazard after a power failure, Coast Guard Regulations (46 CFR) require motor controllers for auxiliaries vital to the propelling equipment to be provided with ________________. A. overload protection B. low voltage protection C. low voltage release D. reverse current protection

Description : Where automatic restart does not present a hazard after a power failure, Coast Guard Regulations (46 CFR) require motor controllers for auxiliaries vital to the propelling equipment to be provided ... overload protection B. low voltage protection C. low voltage release D. reverse current protection

Last Answer : Answer: C

Which of the following statements is true concerning the motor controller diagram shown in the illustration? EL-0023 A. Terminal 'T2' is hot only on high speed. B. Both indicating lights will be lit on both high and low speeds as they are connected to the common lead when the motor is running. C. Overload protection is provided for high speed operation only. D. 'L2' is always connected to 'T2' whenever the motor is running.

Description : Which of the following statements is true concerning the motor controller diagram shown in the illustration? EL-0023 A. Terminal 'T2' is hot only on high speed. B. Both indicating lights will be lit on ... high speed operation only. D. 'L2' is always connected to 'T2' whenever the motor is running.

Last Answer : Answer: D

Protection against sustained overloads occurring in molded-case circuit breakers is provided by a/an __________. A. overvoltage release B. thermal acting trip C. thermal overload relay D. current overload relay

Description : Protection against sustained overloads occurring in molded-case circuit breakers is provided by a/an __________. A. overvoltage release B. thermal acting trip C. thermal overload relay D. current overload relay

Last Answer : Answer: B

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)

Coast Guard Regulations (46 CFR) require that each alternating current generator arranged for parallel operation shall be provided with _____________. A. more than one means of excitation B. individual circuit fuses C. a high back-pressure trip D. a reverse-power trip

Description : Coast Guard Regulations (46 CFR) require that each alternating current generator arranged for parallel operation shall be provided with _____________. A. more than one means of excitation B. individual circuit fuses C. a high back-pressure trip D. a reverse-power trip

Last Answer : Answer: D

As shown in the illustration, the generator field is excited with DC current provided by ____________. EL-0016 A. conductors '1', '2' and '3' B. inductor 'L1' C. rectifier 'CR1' D. winding 'S-2'

Description : As shown in the illustration, the generator field is excited with DC current provided by ____________. EL-0016 A. conductors '1', '2' and '3' B. inductor 'L1' C. rectifier 'CR1' D. winding 'S-2'

Last Answer : Answer: C

The purpose of the reverse power relay, provided on a ship's service alternator panel, is to trip the circuit in the event of ______________. A. main circuit overload B. high power transfer C. generator overspeeding D. alternator motorization

Description : The purpose of the reverse power relay, provided on a ship's service alternator panel, is to trip the circuit in the event of ______________. A. main circuit overload B. high power transfer C. generator overspeeding D. alternator motorization

Last Answer : Answer: D

Automatic voltage regulators provided on switchboards function to _____________. A. regulate the AC load on the generator B. protect the switchboard from high voltage C. govern prime mover speed to control voltage D. vary the field excitation to the generators

Description : Automatic voltage regulators provided on switchboards function to _____________. A. regulate the AC load on the generator B. protect the switchboard from high voltage C. govern prime mover speed to control voltage D. vary the field excitation to the generators

Last Answer : Answer: D

As load is added to an AC generator provided with constant field excitation, the prime mover slows down with the effect of ____________. A. lowering frequency and lowering generated voltage B. increasing frequency and increasing generated voltage C. increasing frequency and lowering generated voltage D. lowering frequency and increasing generated voltage

Description : As load is added to an AC generator provided with constant field excitation, the prime mover slows down with the effect of ____________. A. lowering frequency and lowering generated ... C. increasing frequency and lowering generated voltage D. lowering frequency and increasing generated voltage

Last Answer : Answer: A

What type of cooling is provided for Generator in power plant?

Description : What type of cooling is provided for Generator in power plant?

Last Answer : Hydrogen gas cooling is employed for large size generators because of better heat carrying ability of the hydrogen. Hydrogen cooling is provided for rotors and core of the generator. Water cooling is provided for the stator of the alternator.

Which one of the following statements regarding the Human Rights Council is not correct? (1) It is an inter-governmental body within the United Nations system made up of all members of the UN (2) It is responsible for the promotion and protection of all human rights around the globe. (3) It replaced the former United Nations Commission on Human Rights. : (4) It is made up of 47 UN Member States which are elected by the UN General Assembly.

Description : Which one of the following statements regarding the Human Rights Council is not correct? (1) It is an inter-governmental body within the United Nations system made up of all members of the UN (2) It is ... : (4) It is made up of 47 UN Member States which are elected by the UN General Assembly.

Last Answer : (1) It is an intergovernmental body within the United Nations system made up of all members of the UN Explanation: The United Nations Human Rights Council (UNHRC) is a United Nations body whose mission ... seat is three years, and no member may occupy a seat for more than two consecutive terms.

Which of the following comes under the jurisdiction of both the High Court and the Supreme Court? (1) Disputes between the states inter se (2) Protection against the violation of the Constitution (3) Protection of Fundamental Rights (4) Disputes between Centre and the States

Description : Which of the following comes under the jurisdiction of both the High Court and the Supreme Court? (1) Disputes between the states inter se (2) Protection against the violation of the Constitution (3) Protection of Fundamental Rights (4) Disputes between Centre and the States

Last Answer : (3) Protection of Fundamental Rights Explanation: Article 32 of the Indian Constitution confers the Right to Constitutional Remedies for the protection of Fundamental Rights contained in Part III, It states ... may be appropriate, for the enforcement of any of the rights conferred by this Part.

For which of the following ratings of the transformer differential protection is recommended ? (a) above 30 kVA. (b) equal to and above 5 MVA (c) equal to and above 25 MVA (d) none of the above

Description : For which of the following ratings of the transformer differential protection is recommended ? (a) above 30 kVA. (b) equal to and above 5 MVA (c) equal to and above 25 MVA (d) none of the above

Last Answer : (b) equal to and above 5 MVA

Large internal faults are protected by (a) merz price percentage differential protection (b) mho and ohm relays (c) horn gaps and temperature relays (d) earth fault and positive sequence relays

Description : Large internal faults are protected by (a) merz price percentage differential protection (b) mho and ohm relays (c) horn gaps and temperature relays (d) earth fault and positive sequence relays

Last Answer : (a) merz price percentage differential protection

Explain the “Differential Protection Scheme” used for alternators with neat labeled diagram.

Description : Explain the “Differential Protection Scheme” used for alternators with neat labeled diagram.

Last Answer : Differential Protection Scheme for Alternator: Figure shows the differential protection provided to 3 phase alternator. Here identical CTs are placed on both sides of 3 phase alternator and ... causing its operation. Relay sends trip signal to the CB, thereby alternator circuit is tripped.

Explain differential protection scheme for busbars with neat sketch.

Description : Explain differential protection scheme for busbars with neat sketch.

Last Answer : Differential Protection Scheme for Bus bar:  Under normal conditions, the sum of the currents entering the bus bar zone is equal to those leaving it and no current flows through the relay ... of these currents will flow through the relay coil causing opening of circuit breaker of bus-bar.

List two limitations of Differential-Protection scheme for transformer.

Description : List two limitations of Differential-Protection scheme for transformer.

Last Answer : Limitations of Differential Protection Scheme of Transformer:  1) Due to the magnetization characteristics of the CTs used, the ratio errors change with respect to the circulating currents.  2) ... & improper operation.  5) Inrush of magnetizing current may lead to inadvertent operation.

Explain differential protection of busbar.

Description : Explain differential protection of busbar.

Last Answer : Differential protection Scheme for bus bar: Under normal conditions the sum of the currents entering the bus bar zone is equal to those leaving it and no current flows through the relay ... . The difference of these currents will flow through the relay coil causing opening of circuit breaker.

Write down limitation of differential protection of transformer.

Description : Write down limitation of differential protection of transformer.

Last Answer : Limitations of differential protection of transformer: 1) Due to the magnetization characteristics of the CTs used, the ratio errors change with respect to the circulating currents. 2) The pilot wires ... current (higher imbalance) due to which accuracy of sensing & operation is decreased. 

A series resistance is added to the over-current relay in a bus bar differential protection scheme which:

Description : A series resistance is added to the over-current relay in a bus bar differential protection scheme which: a. Helps to develop some voltage across it which otherwise should appear across the relay and is ... the effects of CT saturation and lowers the pickup value of the relay d. All of the above 

Last Answer : A series resistance is added to the over-current relay in a bus bar differential protection scheme which: a. Helps to develop some voltage across it which otherwise should appear across the relay and is ... the effects of CT saturation and lowers the pickup value of the relay d. All of the above 

Why Isolation switches are provided along with the circuit breakers?

Description : Why Isolation switches are provided along with the circuit breakers?

Last Answer : Isolation switches are provided for separating the disconnected element from the live portion of the system for the purpose of safety

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

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

Last Answer : Ans:

An entity, relying on the transmission, switching and local distribution facilities of local exchange and inter-exchange operators, and overseas carriers, offers enhanced services beyond those ordinarily provided by such carriers. A. International carrier B. Value-added service provided C. Inter-exchange carrier D. Local exchange carrier

Description : An entity, relying on the transmission, switching and local distribution facilities of local exchange and inter-exchange operators, and overseas carriers, offers enhanced services beyond those ordinarily ... B. Value-added service provided C. Inter-exchange carrier D. Local exchange carrier

Last Answer : B. Value-added service provided

Which of the following should be the FIRST step in removing a generator from parallel operation? A. Trip the generator off the switchboard. B. Turn off all electrical equipment. C. Remove the load from the 'off going' generator. D. Increase the cycles of the generator staying on the line.

Description : Which of the following should be the FIRST step in removing a generator from parallel operation? A. Trip the generator off the switchboard. B. Turn off all electrical equipment. C. Remove the load from the 'off going' generator. D. Increase the cycles of the generator staying on the line.

Last Answer : Answer: C

Maximum Differential pressure: a. Is the maximum authorized pressure difference between the inside of the fuselage and the atmospheric ambient pressure b. Is the absolute pressure provided by the vacuum pump c. Is the pressure loss over a given time limit d. Is the absolute pressure the cabin pressure ducting is designed to carry

Description : Maximum Differential pressure: a. Is the maximum authorized pressure difference between the inside of the fuselage and the atmospheric ambient pressure b. Is the absolute pressure provided by the vacuum ... time limit d. Is the absolute pressure the cabin pressure ducting is designed to carry

Last Answer : a. Is the maximum authorized pressure difference between the inside of the fuselage and the atmospheric ambient pressure

Maximum Differential pressure: a. Is the maximum authorized pressure difference between the inside of the fuselage and the atmospheric ambient pressure b. Is the absolute pressure provided by the vacuum pump c. Is the pressure loss over a given time limit d. Is the absolute pressure the cabin pressure ducting is designed to carry

Description : Maximum Differential pressure: a. Is the maximum authorized pressure difference between the inside of the fuselage and the atmospheric ambient pressure b. Is the absolute pressure provided by the ... time limit d. Is the absolute pressure the cabin pressure ducting is designed to carry

Last Answer : a. Is the maximum authorized pressure difference between the inside of the fuselage and the atmospheric ambient pressure

Honey contain glucose and fructose along with some other ingredients, it has greater viscosity due to------? A. hydrogen bonding B. irregular shape of the molecules C. irregular shape of the molecules and strong inter-molecular forces (Answer) D. greater molecular size

Description : Honey contain glucose and fructose along with some other ingredients, it has greater viscosity due to------? A. hydrogen bonding B. irregular shape of the molecules C. irregular shape of the molecules and strong inter-molecular forces (Answer) D. greater molecular size

Last Answer : C. irregular shape of the molecules and strong inter-molecular forces (Answer)

If x% is the gradient of an alignment and y% is the gradient after proper super-elevation along a curved portion of a highway, the differential grade along the curve, is (A) (x + y) % (B) (x - y) % (C) (y - x) % (D) (y + x) %

Description : If x% is the gradient of an alignment and y% is the gradient after proper super-elevation along a curved portion of a highway, the differential grade along the curve, is (A) (x + y) % (B) (x - y) % (C) (y - x) % (D) (y + x) %

Last Answer : Answer: Option C

How the alternator can be protected from inter-turn fault?

Description : How the alternator can be protected from inter-turn fault?

Last Answer : Inter-turn fault Protection: Figure shows scheme for one phase only. It is identical for other phases. Under normal working condition, the two currents in the stator winding sections (S1 and S2) are ... relay coil to operate it, leading to isolation of the alternator from the power system.

While Taking A Turn, What Action Differential Makes?

Description : While Taking A Turn, What Action Differential Makes?

Last Answer : An increase in the speed of the outer wheel.

Explain the process of commutation in a dc machine. Explain what are inter-poles and why they are required in a dc machine.

Description : Explain the process of commutation in a dc machine. Explain what are inter-poles and why they are required in a dc machine.

Last Answer : Commutation: It is phenomenon when an armature coil moves under the influence of one pole- pair; it carries constant current in one direction. As the coil moves into the influence of the ... region of the main poles and therefore influence the armature coils only when these undergo commutation.

Which of the following operating characteristics for DC motors is considered to give high starting torque? A. series B. shunt C. cumulative-compound D. differential-compound

Description : Which of the following operating characteristics for DC motors is considered to give high starting torque? A. series B. shunt C. cumulative-compound D. differential-compound

Last Answer : Answer: A

Figure 'A' of the diagram shown in the illustration represents a ______________. EL-0092 A. differential transformer B. saturable reactor C. synchro system D. magnetic amplifier

Description : Figure 'A' of the diagram shown in the illustration represents a ______________. EL-0092 A. differential transformer B. saturable reactor C. synchro system D. magnetic amplifier

Last Answer : Answer: C