PBL Report
Electrical Machines
Muhammad Anas (F2021019008)
Submitted to: DR. Asif Hussain
 Why we use squirrel cage winding in the rotor of high power large
synchronous generator?
The use of a squirrel cage winding in the rotor of a high-power large synchronous generator is primarily
based on its advantages in terms of simplicity, reliability, and robustness. Here are some reasons why
squirrel cage windings are commonly employed in the rotor of high-power synchronous generators:
High Reliability: Squirrel cage rotors are known for their simplicity and robustness. They have a
solid construction with no external connections, brushes, or slip rings. This design minimizes the chances
of mechanical failure and enhances the reliability of the generator.
Low Maintenance: Since squirrel cage rotors have a simple and durable design, they require
minimal maintenance compared to other types of rotor windings. This is particularly important for highpower generators, where downtime and maintenance costs need to be minimized.
Rugged Construction: Squirrel cage rotors are structurally strong and can withstand high
mechanical stresses. This makes them well-suited for high-power applications where the generator is
subjected to heavy loads and operational stresses.
Ease of Manufacturing: Squirrel cage rotors are relatively easy and cost-effective to manufacture
compared to more complex rotor designs. This factor is crucial when dealing with large-scale generators,
where production efficiency and cost considerations are significant.
High Short-Circuit Strength: The construction of the squirrel cage winding provides excellent
short-circuit strength, which is important in large generators where short circuits can produce significant
mechanical and thermal stresses.
Improved Dynamics: Squirrel cage rotors offer good dynamic response characteristics, making
them suitable for applications where rapid changes in load and operating conditions are expected.
Reduced Windage Losses: The absence of external brushes and slip rings reduces windage
losses in squirrel cage rotors. This is advantageous in large generators where minimizing losses is
essential for efficiency.
Cost-Effectiveness: Squirrel cage rotors are generally more cost-effective to produce and maintain
compared to other rotor types. This cost advantage is crucial for high-power generators where economies
of scale become significant.
While squirrel cage rotors are widely used in high-power synchronous generators, it's essential to consider
the specific requirements of the application and weigh the advantages and disadvantages of different rotor
designs based on factors such as efficiency, cost, and operational considerations.