Question

In: Electrical Engineering

1) List various types of faults occurring in generator and their consequences.

1) List various types of faults occurring in generator and their consequences.

Solutions

Expert Solution

The common faults are

  1. Stator Faults
  2. Rotor Faults
  3. Operational faults

Stator Faults:

Stator faults are those which occur on the stator of the Alternator. These faults can be categorized into

1. Phase-to-Phase Faults which occur between two phases

2.   Phase-to-Earth faults which occur between a phase and the ground and

3. Inter-turn Faults which occur between the turns of a winding of the same phase.

Stator faults occur due to failure of the winding insulation. The heat generated by these faults can cause serious damage to the laminated core of the Stator. This may require expensive re-insulation and rebuilding.

Rotor faults:

Rotor Faults on the Alternator when the rotor winding gets grounded or short circuited. The rotor winding is usually ungrounded; hence the first earth fault is not always obvious. However, if a second earth fault occurs on the rotor, the fault becomes a virtual short-circuit through the rotor body. Rotor winding short-circuit leads to an increase of excitation current and a decrease of excitation voltage.

Operational Faults:

Overloading :

Overloading causes the flow of high currents which causes the stator winding to heat up.

Reverse Power:
This occurs due to failure of the prime mover and insufficient torque supplied to the generator.

Underexcitation:
Underexcitation occurs when the excitation to the generator is cut off and the Power factor goes to the leading side. This can lead to the failure of the diodes on the rotor and pole slipping.

Negative Phase Sequence:
Negative Phase sequence occurs when the Alternator is loaded in an unbalanced manner. That is, the current on the three phases are not balanced. This results in heating of the Alternator rotor.

Overvoltage :

Overvoltage occurs due to failure of the excitation control system. If the excitation input to the alternator does not match the voltage. It can result in the voltage rising above normal levels and the risk of the winding insulation getting damaged.

Overspeeding:
Overspeeding is an extremely serious and dangerous condition. This occurs when the speed controller regulating the speed of the prime mover fails. When the speed of the alternator rises above the nominal speed, the centrifugal forces developed within the Alternator are so enormous that the poles of a salient pole rotor can get damaged and can come out of the rotor. This can then hit the stator and the alternator will be severely damaged.


Related Solutions

1. List any four types of faults that can occur in power transformers?    2. List any...
1. List any four types of faults that can occur in power transformers?    2. List any four effects of sustained low power factor on equipment. 3. List any four methods that can be used to improve power factor? 4. List any two economic benefits of power factor correction?
1. List the various types of transactions that impact and the direction of the impact on...
1. List the various types of transactions that impact and the direction of the impact on reporting Cash Flows from Investing. 2. List the various types of transactions that impact and the direction of the impact on reporting Cash Flows from Financing. 3. What information does the Stmt of Cash Flows provide?
types of faults in induction machine and how to solve each problem and which types of...
types of faults in induction machine and how to solve each problem and which types of test for the problem online or offline or both of them I can use
types of faults in transformer and each problem how to solve it and which type of...
types of faults in transformer and each problem how to solve it and which type of test for each problem online or offline
The following is a list of various types of economies of scale: The firm can benefit...
The following is a list of various types of economies of scale: The firm can benefit from the specialization and division of labour. It can overcome the problem of indivisibilities. It can obtain inputs at a lower prices. Large containers/machines have a great capacity relative to their surface area. The firm may be able to obtain finance at lower cost. It becomes economical to sell by-products. Production can take place in integrated plants. Risks can be spread with a larger...
List the types of noise and their sources. What are the various ways of enhancing Signal-toNoise...
List the types of noise and their sources. What are the various ways of enhancing Signal-toNoise ratio?
1.         To gain the benefit of _______________, a bank makes various types of loans, to various...
1.         To gain the benefit of _______________, a bank makes various types of loans, to various types of borrowers. A.     guaranteed income B.      diversification C.      more firm-specific risk exposure D.     reduced operational risk E.      reduced off-balance-sheet risk 2.         Argentina unilaterally told its creditors in 2005 that it would henceforth repay only $0.30 for every $1.00 of its debt that was outstanding. Argentina’s creditors had been exposed to ______________ risk, which was then realized. A.     sovereign B.      operational C.      technology D.    ...
- What are the consequences of climate change for organisms?List several consequences of climate change for...
- What are the consequences of climate change for organisms?List several consequences of climate change for organisms and ecosystems.   -Describe a positive feedback loop that may accelerate climate change.
1. Discuss what plagiarism is and the various ways that people plagiarize. 2. State the consequences...
1. Discuss what plagiarism is and the various ways that people plagiarize. 2. State the consequences for plagiarism at The University of Southern Mississippi and in the real world 3. Type one full page or longer, double-spaced, indent paragraphs, and do not plagiarize!
a. explain the various types of rainfall. b. list three factors that influences the energy conversion...
a. explain the various types of rainfall. b. list three factors that influences the energy conversion and intake or not of the agroecosystem ? c. why should the temperature vary across latitude? is it called latitudinal variation? if so why?
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT