## YEAR & SEM:   I-I                                                                 REGULATION: R18

UNIT-I

1. Explain per unit system and Parks transformation.
2. Derive stator flux linkage equations of synchronous machine.
3. Derive Rotor flux linkage equations of synchronous mnachine.
4. Explain per unit system for the rotor and stator of synchronous machine.
5. Derive power and torque equations in per unit system of synchronous machine.
6. Discuss alternative per unit system and transformations.
7. Draw equivalent circuits for direct and quadrature axis of synchronous machine with neat sketch.
8. Derive stator voltage and rotor voltage equations in per unit system of synchronous machine.
9. Derive mathematical model of synchronous machine.
10. Briefly expain the different physical description of synchronous machine.

UNIT-II

1. Explain in detail the concepts of related voltage stability.
2. Discuss concept of voltage collapse in detail.
3. Discuss concept of voltage stability analysis in detail.
4. Briefly explain the prevention of voltage collapse.
5. Discuss the system design measures for prevention of voltage collapse.
6. Discuss the system operating measures for prevention of voltage collapse.
7. Derive the voltage and current equations of synchronous machine.
8. Derive the Formulation of State-space equations of synchronous machine.

9. Draw Equivalent circuits for direct and quadrature axis of synchronous machine.
10. What are the assumptions associated with the mathematical model of synchronous machines?

UNIT-III

1. Briefly explain the Sub-transient and transient inductances of synchronous machine
2. Explain the electrical transient performance characteristics of synchronous machine.
3. Explain the phase short circuit at the terminals of synchronous machines.
4. Explain elimination of dc offset short circuit current.
5. Explain the Simplified models of synchronous machines
6. Explain the improved modeling of saturation.
7. Explain the open circuit and short circuit characteristics of synchronous machines
8. Explain the constant flux linkage model including the effect of sub-transient circuit.
9. Determination of synchronous machine parameters.
10. Derive the state model for multi machine system with one axis model.

UNIT-IV

1. Explain frequency mode and Excitation systems .

2. Draw the block diagram and explain the excitation control system.

3. Discuss the different types of AC excitation system
4. Explain the need for digital stabilizer with neat sketch?
5. Explain the characteristics of small signal stability problems.
6. Briefly explain the Philips model.
7. Briefly explain the Heffron model.

8. Explain small signal stability of single machine infinite bus.

9. Distinguish between the Philips & Heffron models?

UNIT-V

1. Draw the Block diagram of SMIB configuration represented by classical models.

2. Discuss in detail with necessary equations and block diagrams of SMIB configuration with the inclusion of PSS and the effect of increasing the phase lead provided by the PSS.

3. Explain in detail with necessary equations and block diagram of supplamentary control of synchronous machine excitation using the three types of PSS

4. What is meant by PSS? Briefly explain it.

5. Derive the Modeling of Induction Motors.

6. Explain about the Prime mover controllers.