Multiple-Choice Quiz on Power System Protection

What is the primary function of protective relays in a power system?

• Increase voltage levels

• Detect and isolate faults

• Control power generation

• Improve power factor

Which type of relay determines the direction of fault current?

• Overcurrent relay

• Distance relay

• Directional relay

• Differential relay

What does a Buchholz relay protect against in a transformer?

• Overvoltage

• Internal faults and gas accumulation

• Overcurrent conditions

• Lightning strikes

Which protection scheme is used to protect generators from loss of excitation?

• Reverse power protection

• Differential protection

• Distance protection

• Loss of excitation relay

What is the primary purpose of a power system stabilizer (PSS)?

• Increase voltage levels

• Improve power system damping and stability

• Provide reactive power support

• Reduce transmission losses

Which of the following protection schemes is used for busbars?

• Differential protection

• Overcurrent protection

• Reverse power protection

• Distance protection

What is the primary function of a reclosing relay?

• Detect high-voltage surges

• Automatically restore power after a transient fault

• Control generator speed

• Detect phase faults

Which relay is commonly used to detect underfrequency conditions?

• Overcurrent relay

• Frequency relay

• Distance relay

• Directional relay

What type of fault is most common in power systems?

• Three-phase fault

• Line-to-line fault

• Line-to-ground fault

• Double-line-to-ground fault

What is the primary function of a surge arrester?

• To regulate system voltage

• To protect equipment from transient overvoltages

• To act as a backup relay

• To monitor system frequency