JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisite

Electrical Machines

Course Objectives:

• To identify the methods and assumptions in modeling of machines.
• To recognize the different frames for modeling of AC machines.
• To write voltage and torque equations in state space form for different machines.

Course Outcomes

After completion of the course, students will be able to:

• Develop the mathematical models of various machines like, induction motor and Synchronous machines, permanent magnet synchronous motor, brushless DC motor using modeling equations.
• Analyze the developed models in various reference frames.

UNIT - I

Basic Two-pole DC machine, Primitive 2-axis machine, Voltage and Current relationship, Torque equation. Mathematical model of separately excited DC motor and DC Series motor in state variable form, Transfer function of the motor, Numerical problems. Mathematical model of D.C. shunt motor, D.C. Compound motor in state variable form, Transfer function of the motor, Numerical Problems.

UNIT - II

Linear transformation, Phase transformation (a, b, c to α, β, o), Active transformation (α. β, o to d, q), Circuit model of a 3-phase Induction motor, Linear transformation, Phase Transformation, Transformation to a Reference frame, Two axis models for induction motor, “d-q” model based DOL starting of induction motors.

UNIT - III

Voltage and current Equations in stator reference frame, Equation in Rotor reference frame, Equations in a synchronously rotating frame, Torque equation, Equations in state – space form.

UNIT - IV

Circuit model of a 3-phase Synchronous motor, two- axis representation of Synchronous Motor. Voltage and current Equations in state – space variable form, Torque equation, and “dq” model based short circuit fault analysis, Emphasis on voltage, Frequency and recovery time.

UNIT - V

Modeling of Permanent Magnet Synchronous motor, Modeling of Brushless DC Motor.

TEXTBOOKS:

• 1. P.S. Bimbhra, “Generalized Machine theory”, Khanna Publishers.
• 2. Paul C. Krause, Oleg wasynezuk, Scott D. Sudhoff, “Analysis of electric machinery and Drives systems”.

REFERENCES:

• 1. Vedam Subranmanyam, “Thyristor control of Electric Drives”.
• 2. Prabha Kundur, “Power System Stability and Control”, EPRI.
• 3. Article in IEEE Transactions on Energy Conversion, “Performance optimization of induction motors during Voltage-controlled soft starting”, July, 2004.
• 4. Nithin K.S, Dr.Bos Mathew Jos, Muhammed Rafeek, Dr.Babu Paul, “A Novel Method for Starting of Induction Motor with Improved Transient Torque Pulsations”, International Journal of Engineering and Innovative Technology (IJEIT) Volume 2, Issue 8, February 2013. M. Tech – I Semester L T P C 3 0 0 3