SARDAR RAJA COLLEGE OF ENGINEERING

DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING

MICRO LESSON PLAN

SUBJECT NAME : SPECIAL ELECTRICAL MACHINES

SUBJECT CODE : EE73

YEAR : IV

SEM : VII

STAFF NAME Ms.M.RATHIKA

A.P/ EEE

SARDAR RAJA COLLEGE OF ENGINEERINGDEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING

MICRO LESSON PLAN

EE 73 SPECIAL ELECTRICAL MACHINES L T P C

3 0 0 3AIM

To expose the students to the construction, principle of operation and performance of special electrical machines as an extension to the study of basic electrical machines.

OBJECTIVES To impart knowledge on

i. Construction, principle of operation and performance of synchronous reluctance motors.ii. Construction, principle of operation, control and performance of stepping motors.iii. Construction, principle of operation, control and performance of switched reluctance motors.iv. Construction, principle of operation, control and performance of permanent magnet brushless

D.C. motors.v. Construction, principle of operation and performance of permanent magnet synchronous

motors.

1. SYNCHRONOUS RELUCTANCE MOTORS 9Constructional features – Types – Axial and Radial flux motors – Operating principles – Variable Reluctance and Hybrid Motors – SYNREL Motors – Voltage and Torque Equations - Phasor diagram - Characteristics.

2. STEPPING MOTORS 9Constructional features – Principle of operation – Variable reluctance motor – Hybrid motor – Single and multi stack configurations – Torque equations – Modes of excitations – Characteristics – Drive circuits – Microprocessor control of stepping motors – Closed loop control.

3. SWITCHED RELUCTANCE MOTORS 9Constructional features – Rotary and Linear SRMs - Principle of operation – Torque production – Steady state performance prediction- Analytical method -Power Converters and their controllers – Methods of Rotor position sensing – Sensorless operation – Closed loop control of SRM - Characteristics.

4. PERMANENT MAGNET BRUSHLESS D.C. MOTORS 9Permanent Magnet materials – Magnetic Characteristics – Permeance coefficient - Principle of operation – Types – Magnetic circuit analysis – EMF and torque equations –Commutation – Power controllers – Motor characteristics and control.

5. PERMANENT MAGNET SYNCHRONOUS MOTORS 9Principle of operation – Ideal PMSM – EMF and Torque equations – Armature reaction MMF – Synchronous Reactance – Sinewave motor with practical windings - Phasor diagram – Torque/speed characteristics - Power controllers - Converter Voltampere requirements.

TOTAL : 45 PERIODS

TEXT BOOKS1. T.J.E. Miller, ‘Brushless Permanent Magnet and Reluctance Motor Drives’, Clarendon Press, Oxford, 1989. 2. T. Kenjo, ‘Stepping Motors and Their Microprocessor Controls’, Clarendon Press London, 1984.

REFERENCES1. R.Krishnan, ‘Switched Reluctance Motor Drives – Modeling, Simulation, Analysis, Design and Application’, CRC Press, New York, 2001.2. P.P. Aearnley, ‘Stepping Motors – A Guide to Motor Theory and Practice’, Peter Perengrinus, London, 1982.3. T. Kenjo and S. Nagamori, ‘Permanent Magnet and Brushless DC Motors’, Clarendon Press, London, 1988.

MICRO LESSON PLANWEEK HOURS LECTURER TOPICS ASSIGNMENT/

AV CLASS REFERENCE

UNIT-I SYNCHRONOUS RELUCTANCE MOTORS

I

1 Constructional features AV CLASS T1 - 5962 Types – Axial and Radial flux motors T1 - 5963 Operating principles T1 - 5984 Variable Reluctance and Hybrid Motors T1 - 5465 SYNREL Motors Assignment I T1 - 626

II6,7 Voltage and Torque Equations T1 - 5358 Phasor diagram T1 - 5469 Characteristics T1 - 571

UNIT-II STEPPING MOTORSII 10 Constructional features - Principle of operation AV CLASS T2 - 7

III

11 Variable reluctance motor T2 - 2812 Hybrid motor T2 - 3713 Single and multi stack configurations Assignment II T2 - 3614 Torque equations T2 - 7115 Modes of excitations T2 - 51

IV

16 Characteristics T2 - 6617 Drive circuits T2-12618 Microprocessor control of stepping motors –

Closed loop controlT2-132

UNIT-III SWITCHED RELUCTANCE MOTORS

IV19 Constructional features - Rotary and Linear SRMs AV CLASS T1 – 152 , R1-

5320 Principle of operation T1-149

V

21 Torque production T1-15522 Steady state performance prediction- Analytical

methodNotes

23 Power Converters and their controllers Assignment III T1 -17324 Methods of Rotor position sensing T1-18825 Sensorless operation T1-190

VI 26 Closed loop control of SRM R1-316

VI 27 Characteristics R1-317UNIT-IV PERMANENT MAGNET BRUSHLESS D.C. MOTORS

VI28 Permanent Magnet materials T1-3429 Magnetic Characteristics T1-3430 Permeance coefficient - Principle of operation AV CLASS T1-42

VII

31 Types T1-5432 Magnetic circuit analysis T1-5833 EMF and torque equations T1-6034 Commutation T1-8135 Power controllers Assignment IV T1-83

VIII 36 Motor characteristics and control T1-84UNIT-V PERMANENT MAGNET SYNCHRONOUS MOTORS

VIII

37 Principle of operation – Ideal PMSM AV CLASS T1-8838 EMF and Torque equations T1-89, R3-37739 Armature reaction MMF T1-9440 Synchronous Reactance T1-96

IX

41 Sinewave motor with practical windings Assignment V T1-9642 Phasor diagram R3- 354,T1-

10043 Torque/speed characteristics T1-10344 Power controllers T1- 11245 Converter Voltampere requirements. T1-125

ASSIGNMENT QUESTIONS

UNIT-I SYNCHRONOUS RELUCTANCE MOTORS

Explain in detail about SYNREL Motors

UNIT-II STEPPING MOTORS

Explain in detail the configurations of Single and multi stack

UNIT-III SWITCHED RELUCTANCE MOTORS

Explain the types of power controllers for SRM

UNIT-IV PERMANENT MAGNET BRUSHLESS D.C. MOTORS

Explain the rotor position sensors for BLPM motors

UNIT-V PERMANENT MAGNET SYNCHRONOUS MOTORS

Comparison of BLPMSNW motor with BLPM square wave motor.

SARDAR RAJA COLLEGE OF ENGINEERINGDEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING

EE 73 – SPECIAL ELECTRICAL MACHINESQUESTION BANK

UNIT – I SYNCHRONOUS RELUCTANCE MOTOR

PART – A1. What is the basic principles of synchronous reluctance motor?2. Compare synchronous reluctance motor with Switched reluctance motor.3. What are the advantages and disadvantages of synchronous reluctance motor? 4. Mention some applications of synchronous reluctance motor. 5. Define synchronous reluctance. 6. Define reluctance torque. 7. What are the main differences between the axial and radial airgap motors.8. Draw the steady state phasor diagram of synchronous reluctance motor. 9. List out the primary design considerations of synchronous reluctance motor. 10. State the advantages of synchronous reluctance motor over PM machines. 11.What are factors to be considered while designing a vernier motor? 12.Write the torque equation of synchronous reluctance motor13.What are the applications of Vernier motor?14.What is an axial flux motor?

PART – B1. Explain the constructional & operational features of a variable reluctance motor. Draw and explain its unipolar wave drive, bipolar full step drive , bipolar 6-step drive waveforms. (16)2.(i) Derive the voltage and torque equations of a synchronous reluctance motor (10) (ii) Explain the phasor diagram of the synchronous reluctance motor (6)2. Explain in detail about classification of synchronous reluctance motor. (16)4. Derive the torque equation of synchronous reluctance motor. (16)5. Draw and explain the characteristics of synchronous reluctance motor. (16)6. Explain in detail about vernier motor. (16)7.Derive an equation for open circuit emf equation of synchronous reluctance motor. (16)

UNIT – II STEPPER MOTORPART – A

1.What is stepper motor? 2. Define the term step angle.3.Draw any two drive circuits for stepper motor4. Define slewing. 5. What are the different modes of excitation used in variable reluctance stepper motor? 6. Mention some applications of stepper motor? 7. Define resolution. 8. What are the advantages and disadvantages of stepper motor? 9. What is micro stepping in stepper motor? 10. Differential between VR, PM and hybrid stepper motor? 11. Define holding torque & detent torque.

12. Define pull-in torque and pull-out torque. 13. Draw the typical dynamic characteristics of a stepper motor. 14. What is slew range? 15. What is synchronism in stepper motor? 16. Draw the block diagram of the drive system of a stepper motor.

PART – B1. Explain the construction and various modes of excitation of

(i) VR stepper motor. (ii) PM stepper motor. (16)2.(i) Briefly explain the construction and working principle of a Hybrid motor. (7) (ii) Explain in detail about the various types of drive circuits for stepper motors. (9) 3. State and explain the static and dynamic characteristics of a stepper motor. (16)4. Explain in detail about different types of power drive circuits for stepper motor. (16)5. Explain the mechanism of torque production in VR stepper motor. (16)

UNIT – III SWITCHED RELUCTANCE MOTORPART – A

1. Write the torque equation of Switched Reluctance Motor.2. Name any two current control schemes used for Switched Reluctance Motor.3. What is switched reluctance motor? 4. What are the essential differences between a stepper motor and SRM? 5. Mention any four advantages of switched reluctance motor. 6. What is the different power controllers used for the control of SRM? 7. Why rotor position sensor is essential for the operation of SRM? 8. What is meant by energy ratio? 9. Draw the ‘λ– i’ curve for SRM. 10. What is phase winding? 11.What are power controllers?12.What are the significant of closed loop control in SRM?

PART – B1. Explain the construction and working principle of switched reluctance motor. (16)2. Describe the various power controller circuits applicable to switched reluctance motor and explain the operation of any one scheme with suitable circuit diagram. (16)3.Draw and explain the general torque-speed characteristics of SRM and discuss the type of control strategy used for different regions of the curve. Sketch the typical phase current waveforms of low speed operation. (16)4. (i)Draw the schematic diagram and explain the operation of a ‘C’ dump converter (10) (ii)What is the need for rotor position sensing in switched reluctance motor? (6)5. Derive the torque equation of SRM. (16)6. Describe the hysteresis type and PWM type current regulator for one phase of a SRM (16)

UNIT – IV PERMANENT MAGNET BRSHLESS DC MOTORPART – A

1. What are the advantages & disadvantages of dc brushless dc motor drives? 2. List out the various permanent magnet materials. 3. Draw the magnetic equivalent circuit of 2 pole permanent magnet brushless dc motor 4. Why a PMBLDC motor is called an electronically commutated motor?

5. Write the torque and emf equation of square wave brushless motor. 6. Mention some applications of PMBLDC motor. 7. What are the differences between the mechanical and electronic Commutator? 8. What are the difference between the conventional dc motor and PMBLDC motor? 9. What are the classifications of PMBLDC motor? 10. What are the two types of rotor position sensors? 11. What are the materials used for making Hall IC pallet?

PART – B1.(i) Sketch the structure of controller for PMBLDC motor and explain the functions of each block. (10) (ii)Explain the operation an of electronic Commutator (6)2. Explain the closed loop control scheme of a permanent magnet brushless dc motor drive with a suitable schematic diagram. (16)3. (i) Drive the expressions for the emf and torque of a PMBLDC motor. (10) (ii) Sketch the torque-speed characteristics of a PMBLDC motor. (6)4. Discuss the use of Hall sensors for position sensing in PMBLDC motor. (16)5.(i)Explain microprocessor based control of PM sychronous motor(10) (ii)Discuss self control model of PM synchronous reluctance motor(6)

UNIT – V PERMANENT MAGNET SYNCHRONOUS MOTORPART – A

1.What are the features of closed-loop speed control of load commutated inverter fed synchronous motor drive?2.Why PMSM operating in self controlled mode is known commutatorless dc motor?3.What is permanent magnet synchronous motor?4. What are the advantages and disadvantages of PMSM?5. What are the applications of PMSM?6. What are the different types of PMSM?7. Compare electromagnetic excitation with permanent magnet of PMSM.8. Clearly explain the differences between the synchronous reluctance motor and PMSM.9. What are the differences in the constructional features of PMBLDC motor and PMSM?10. Write the emf equation and torque equation of PMSM. 11. What is meant by self control? 12. What is ‘pulsed mode’? 13. What is load commutation? 14.List the advantages of microprocessor based control of PMSM.

PART – B1.(i)Explain the construction and operation of Permanent Magnet Synchronous Motors. (10) (ii)Write short notes on self control of Permanent Magnet Synchronous Motors. (6)2. Explain the principle of operation of a sine wave PM synchronous machine in detail. Draw its phasor diagram and derive its torque equation. (16)3. (i)Derive the emf equation of PMSM. (8) (ii)Derive the expression for the d-axis synchronous reactance of the PMSM.(8)4. Derive the expressions for power input and torque of a PMSM. Explain how its torque speed characteristics are obtained. (16)5. (i)Explain in detail the vector control of permanent magnet synchronous motor. (10) (ii) What is synchronous reactance? Explain. (6)

B.E/B.TECH DEGREE EXAMINATION NOVEMBER/DECEMBER 2010Seventh Semester

Electrical and Electronics EngineeringEE1001-SPECIAL ELECTRICAL MACHINES

Answer all the questions PART A (10X2=20 marks)1. Compare synchronous reluctance motor with Switched reluctance motor.2. Why the power factor of Synchronous reluctance motor is much lower than Permanent magnet motor?3. Write down the equation for step angle of stepper motor.4. Draw the equivalent circuit of a winding in a stepper motor.5. Differentiate Variable reluctance stepper motor with Switched reluctance motor.6. Define Energy ratio.7. What is PMBLDC machine?8. What is electronic commutator?9. Draw the torque-speed characteristics of PMSM.10. Define Synchronous reluctance.

PART-B(5X16=80 marks)11.(a) Derive the open circuit emf of Synchronous reluctance motor. (16) Or11.(b)(i) Explain the steady state phasor diagram of Synchronous motor. (8) (ii) Derive the expression for d-axis synchronous reactance of a permanent magnet Synchronous reluctance motor. (8)

12.(a) Explain the modes of excitation of a stepper motor with neat diagram. (16) Or12.(b) With a neat sketch, explain the different types of Logic sequencers for a stepper motor. (16)

13.(a)(i)Derive the torque expression for Switched reluctance motor. (8) (ii)Explain the non linear analysis of SRM. (8) Or13.(b)(i) Explain the role of microprocessors in control of switched reluctance motor. (8) (ii) Explain the speed-torque characteristics of SRM. (8)

14.(a)(i) Prove that the torque equation in BLDC motor is similar to that of dc motor. (10)(ii) Compare electronic commutator and mechanical commutator. (6) Or14. (b)(i) Derive the equation for permeance coefficient (PC) of BLDC motor. (6)(ii) Explain the construction and principle of operation of PMBLDC with neat diagram.

(10)15. (a)(i) Derive self and mutual inductance of Permanent magnet synchronous motor. (10) (ii) Compare the volt-ampere and torque/ampere of a BLDC with PMSM. (6) Or15. (b) With a neat sketch, explain the microprocessor based speed control of PMSM.(16)

B.E/B.TECH DEGREE EXAMINATION APRIL/MAY 2010 Seventh Semester

Electrical and Electronics EngineeringEE1001-SPECIAL ELECTRICAL MACHINES

Answer all the questions. PART-A (10X2=20 marks)1.What are the types of rotor available in synchronous reluctance motor?2.What is vernier motor?3.Give the classification of stepper motor.4.Define the term slewing.5.Draw the speed-torque characteristics of switched reluctance motor.6.List any four applications of switched reluctance motor.7.What are the advantages of PMBLDC motor?8.Give the expression for the emf and torque of a PMBLDC motor.9.What is load commutation?10.What is the magnitude of stator current in PMSM to achieve demagnetization?

PART B(5X16=80 marks)11.(a) Explain the principle of operation and constructional features of different types of synchronous reluctance motor. (16) (Or)(b) Explain the circle diagram and torque speed characteristics of synchronous reluctance motor.

(16)

12.(a)(i) Describe the operation of a variable reluctance type stepper motor. (8)(ii) Draw and explain the torque pulse rate characteristics of a stepper motor. (8) (Or)(b)(i) Explain the working of hybrid motor with neat diagram. (8)(ii) What is stepping angle? A VR stepper motor 8 poles in the stator and they have five teeth in each pole. If the rotor has 50 teeth, calculate the step angle and resolution. (8)

13.(a) Describe the Hysteresis type and PWM type current regulator for one phase of a switched reluctance motor with relevant circuit diagram. (16) (Or)(b)With neat diagram, explain the microprocessor based control of switched reluctance motor.

(16)

14.(a) Explain the construction and principle of operation of PMBLDC motor with neat diagram.(16)

(Or)(b)Describe the operation of power controllers for PMBLDC motor with neat diagram. (16)

15.(a) Explain the construction and performance of a permanent magnet synchronous motor with neat diagram. (16)(b) Derive the emf and torque equation of permanent magnet synchronous motor. (16)