WTT Electrical Systems 3

Question 1

What is the function of the slip rings and brushes in a wound-rotor induction generator?

Accepted Answer

To carry electrical current between the stationary and rotating rotor circuits

Answer

Slip rings and brushes create the electrical connection that allows current to flow between the stationary converter and the rotating rotor windings in a DFIG.

Question 2

A wind turbine's 24 VDC control system shows a ground fault alarm. The FIRST step a technician should take is:

Accepted Answer

Isolate circuit sections systematically to locate the fault before further energizing

Answer

Systematic isolation narrows the fault location safely and prevents damage or misdiagnosis before the fault source is confirmed.

Question 3

What standard specifies electrical safety requirements for working on or near wind turbines in the United States?

Accepted Answer

NFPA 70E

Answer

NFPA 70E establishes arc flash and shock protection requirements for electrical workers, including wind turbine technicians in the US.

Question 4

In a three-phase system, if phase A current is 120 A, phase B is 118 A, and phase C is 119 A, the system is best described as:

Accepted Answer

Balanced within acceptable limits for generator operation

Answer

A current imbalance of less than 2% (here about 1.7%) is within typical acceptable limits for three-phase generator operation.

Question 5

The purpose of a load break switch in a wind turbine's medium-voltage collection system is to:

Accepted Answer

Disconnect circuits under normal load current without interrupting fault current

Answer

A load break switch can open and close under normal load conditions but is not rated to interrupt short-circuit fault currents, unlike a circuit breaker.

(WTT) Wind Turbine Technician Certification Practice Test

(WTT) Wind Turbine Technician Certification Practice Test

WTT Electrical Systems 3