Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
The over voltage surges in power system may be caused by
Lightening
Resonance
Switching
All of above
All of above
Overvoltage surges in a power system are transient voltage elevations that exceed the normal operating range. These surges originate from either external atmospheric disturbances or internal system operational changes, all of which pose a significant risk to electrical insulation.
Overvoltage surges in a power system are transient voltage elevations that exceed the normal operating range. These surges originate from either external atmospheric disturbances or internal system operational changes, all of which pose a significant risk to electrical insulation.
VsurgeтАЛ=LdtdiтАЛ тАФ Voltage spike due to rapid current change during switching
fnтАЛ=2╧АLCтАЛ1тАЛ тАФ Natural frequency of resonance
Lightning causes external surges through electromagnetic induction or direct strikes, injecting massive charge into the grid. Switching surges occur during operations like circuit breaker opening/closing, which cause abrupt changes in current leading to V=LdtdiтАЛ transients. Resonance occurs when the system frequency matches the natural frequency of an LC circuit, leading to extreme voltage amplification.
Lightning causes surges due to high atmospheric energy discharge.
Switching transients result from abrupt interruption of inductive or capacitive currents.
Ferro-resonance can occur in transformers during low load conditions.
Insulation coordination is vital to protect against these voltage magnitudes.
Categorizing surges helps in selecting proper Surge Protection Devices (SPD).
Understanding mechanisms allows for better insulation design.
Excessive surge energy can lead to catastrophic failure of transformer windings.
Repeated transients degrade dielectric materials over time.
Insulation coordination studies.
Designing Lightning Arresters and Surge Suppressors.
Switching surges are generally of lower amplitude than lightning surges but have longer durations.
Lightning surges are considered the most severe external transients in power systems.
D is correct тАФ Overvoltage surges in a power system are generated by a combination of atmospheric factors (lightning), operational procedures (switching), and circuit configurations (resonance).
Always remember that lightning causes external overvoltages, whereas switching and resonance are inherent internal power system characteristics.