Table of Contents
- 1 Does the generator voltage increase when the excitation current increases very much?
- 2 What happens to a DC generator when the field excitation current increases?
- 3 Why does a generator needed to be tripped in the case of loss of excitation?
- 4 Why does the terminal voltage of a self excited DC generator tends to decrease with increasing load current?
- 5 What are natural causes of over voltage?
- 6 How does voltage change in a generator when the load increases?
- 7 What is the output voltage of a magnet generator?
- 8 What happens to voltage when excitation is reduced?
Does the generator voltage increase when the excitation current increases very much?
This is accomplished by the generator excitation system. As the load on the generator is increased, an increase in current flow causes the voltage to drop. The excitation system senses this decrease in voltage and increases the strength of the magnetic field to return the voltage to the desired level.
What happens to a DC generator when the field excitation current increases?
When the load supplied by the generator is increased, IL (and therefore IA) increases. As the armature current increases, the lARA drop increases, so the terminal voltage of the generator falls.
How does excitation work on a generator?
Generators turn mechanical energy into electrical energy by moving electrical conductors in a magnetic field. Excitation creates the electromagnetic field to make this mechanical to electrical conversion occur. The excitation system creates the electromagnetic field in the rotor.
Why does a generator needed to be tripped in the case of loss of excitation?
The loss-of-field protection is normally connected to trip the main generator breaker(s) and the field breaker and transfer unit auxiliaries. The field breaker is tripped to minimize damage to the rotor field in case the loss of field is due to a rotor field short circuit or a slip ring flashover.
Why does the terminal voltage of a self excited DC generator tends to decrease with increasing load current?
As the armature load current increases, the terminal voltage will decrease linearly. The terminal voltage of the separately excited DC generator would be expected to decrease in a linear manner due to the voltage drop across the armature circuit resistance.
Why is my generator bringing low current?
A bad capacity will result in a low voltage reading from the generator as the power being generated will be from the residual magnetism of the rotor (usually about 2-5V). To test a capacitor, a multi-meter that can test capacitance is required. If not, the capacitor should be replaced.
What are natural causes of over voltage?
Natural Causes of Over Voltages
- Examination of over voltages on the power system includes a study of their magnitudes, shapes, durations, and frequency of occurrence.
- External overvoltage: generated by atmospheric disturbances of these disturbances, lightning is the most common and the most severe.
How does voltage change in a generator when the load increases?
Honestly, I don’t see how this one plays out: generators are designed by very knowledgeable and experienced electrical engineers to provide a specific voltage and to be adjustable when that voltage is affect by the connected load. When the load increases, voltage drops and must be adjusted upward by increasing field excitation.
What is the excitation current in a generator?
Generators with field coils use DC current to excite a magnetic field in the field coils. Higher excitation current produces a stronger magnetic fields, which in turn increases the output voltage. For this reason, generators use field excitation as a means of controlling the output voltage.
What is the output voltage of a magnet generator?
The output voltage of any generator is directly proportional to the magnetic field. In the case of a permanent magnet generator, the magnetic field is fixed, which also means the output voltage is fixed. Generators with field coils use DC current to excite a magnetic field in the field coils.
What happens to voltage when excitation is reduced?
When the load increases, voltage drops and must be adjusted upward by increasing field excitation. When load is decreased, available voltage increases because excitation hasn’t been adjusted downward yet. When excitation is reduced, voltage is corrected to normal.