HVDC

The HVDC converter

• Does not consume reactive power

• Consumes as much reactive power as real power

• Consumes 50% of the real power

• None of the above

Fault on a two terminal DC link is removed by

• Breakers on DC side

• Breakers on AC side

• Current control of converters

• None of the above

Voltage regulation of a short transmission line is

• always positive

• always negative

• none

• either positive, negative, or zero

Shunt compensation for long EHV lines is primarily resorted to

• improve voltage profile

• improve stability

• reduce fault currents

• all the above

Transmission voltages in the range 230 kV-765 kV are known as

• High voltage

• Extra High Voltage

• Ultra High Voltage

• Extra Voltage

Which one of the following statements is false? As the transmission voltage increases

• Corona loss decreases

• Conductor copper loss decreases

• Fluctuations may happen

• Cost of insulators, transformers, switches & circuit breakers increases

VSC Converters of HVDC use:

• Thyristors

• Power diode

• Transistors

• All of the above

Generally the Converter transformers used in VSC HVDC systems are _________ as compare to LCC HVDC systems:

• Complex

• Simple

• Identical

• Parallel

“Statement: Corona is violet glow, hissing noise and ozone formation phenomenon.

Assertion: DC lines have no corona”

• Statement is Correct, assertion is Wrong

• Statement is wrong, assertion is correct

• Both are correct

• Both are wrong

Which one of the following statements is true?

• Skin effect at 50 Hz is negligible for larger diameter conductors but becomes appreciable for smaller conductor

• Skin effect at 50 Hz is negligible whatever the diameter of the conductor.

• Skin effect at 50 Hz is negligible for the smaller diameter conductors but becomes appreciable for the larger conductor conductor.

• Skin effect at 50 Hz is negligible for the larger diameter conductors but becomes appreciable for the larger conductor conductor