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4.1 Refer to FIGURE 4.1 and answer the questions that follow - NSC Electrical Technology Power Systems - Question 4 - 2016 - Paper 1
Question 4
4.1 Refer to FIGURE 4.1 and answer the questions that follow. 4.1.1 State whether there is an electrical connection between the stator and rotor. 4.1.2 Describe th... show full transcript
Worked Solution & Example Answer:4.1 Refer to FIGURE 4.1 and answer the questions that follow - NSC Electrical Technology Power Systems - Question 4 - 2016 - Paper 1
Step 1
Step 2
Describe the operation of the motor.
Answer
The operation of a three-phase induction motor begins with a three-phase voltage supply connected across the stator windings. This action creates three-phase currents throughout the stator windings, which generate a rotating magnetic field.
The rotating magnetic field interacts with the rotor, inducing current in it via electromagnetic induction. This interaction between the magnetic field from the stator and the induced magnetic field in the rotor causes the rotor to rotate. The rotor will attempt to follow the rotating magnetic field, resulting in torque production and motor operation.
Step 3
Describe what would happen to the motor if one phase of the stator winding were an open circuit.
Answer
If one phase of the stator winding becomes an open circuit, the motor will still rotate, but it will not develop the correct torque. The loss of one phase reduces the overall current supplied to the rotor, resulting in lower torque and efficiency. This condition can potentially lead to motor stalling or overheating due to unbalanced phase currents.