Power Systems - short answer questions from AMIE exam (Winter 2019)

Answer the following in brief (2 x 10) Why Arcing ground should be avoided? A temporary fault creates an arc between an overhead line and ground. This arc extinguishes and restrikes in repeated and regular manner. This phenomenon is known as arcing ground, which is very common in ungrounded system and should be avoided. What is the function of d.c. reactor? This is used to improve the input power factor of the inverter power supply and reduce harmonics. Why is plug setting required? Selection of the required current setting is by means of a plug setting multiplier, which has a single insulated plug. While the plug is withdrawn for adjusting it to a different current setting during on-load condition, the maximum current tap is automatically connected, thus avoiding the risk of open circuiting the secondary of the C.T. under load condition. Explain the concept of speed governor. This is a fly-ball type of speed governor and constitutes the heart of the system as it senses the change