44608 - Dynamic Behaviour of Electrical Drives (Graduate Course)

Learning outcomes

The course is focused on the mathematical models of electrical machines valid for transient analysis. The aim is to introduce the students to the area of mathematical models and simulation in MATLAB of DC motor drives, brushless motor drives, induction motor drives and switched reluctance motor drives.

Course contents

DC MOTOR DRIVES

Dynamic model of the DC machine. Dynamic behaviour of DC motors with constant flux. Block diagram of a DC motor coupled with a mechanical load. Torque production and control. Closed-loop control of torque and speed. Implementation of the whole drive system in SIMULINK environment of MATLAB. Simulation of starting and speed reversal transients.

 

BRUSHLESS AC MOTOR DRIVES

Dynamic model of permanent magnet synchronous machines with surface mounted magnets. The dq machine and flux equations. Principles of field orientation. Torque production and control. Dynamic model of permanent magnet synchronous machines with interior magnets. The dq machine and flux equations. Torque production and control. Control of the synchronous machine supplied by current controlled PWM inverter. Implementation of torque control schemes in SIMULINK. Simulation of electromechanical transients. Maximum torque capability of the machine in the flux weakening region.

 

INDUCTION MOTOR DRIVES

Dynamic model of induction machines. The dq machine and flux equations. Torque equation. Principles of field orientation. Machine equations and torque in the rotor flux oriented reference frame. Decoupling control of flux and torque in the rotor flux oriented reference frame. Flux models. Direct scheme and indirect scheme of induction motor field oriented control. Control of the induction machine supplied by current controlled PWM inverter. Implementation of torque control schemes in SIMULINK. Simulation of electromechanical transients. Maximum torque capability of the machine in the flux weakening region. Control of the slip-ring induction machine with impressed rotor currents.

 

SWITCHED RELUCTANCE MOTOR DRIVES.

Magnetic circuit analysis. Number of phases and poles. Stator and rotor pole arcs. Feasible triangle for three-phase motors and four-phase motors. Inductance characteristics. Static torque characteristic. Dynamic machine equations. Converters for switched reluctance motors. Control strategies.  Single pulse operation. PWM current controlled operation. Torque-speed characteristic.

 

Readings/Bibliography

I. Boldea, S. A. Nasar : ELECTRIC DRIVES, CRC Press, New York, 1999.

 

P. Vas: VECTOR CONTROL of AC MACHINES, Oxford University Press, New York, 1990.

 

T.J.E. Miller: SWITCHED RELUCTANCE MOTORS AND THEIR CONTROL. Clarendon Press, Oxford, 1993.

 

W. Leonard: CONTROL OF ELECTRICAL DRIVES. Springer-Verlag, Berlin, 2001.

Teaching methods

The theoretical part of the course is integrated by numerical simulations of electrical drives in SIMULINK of MATLAB. Assignments of project works to groups of 3-5 students.

Assessment methods

Discussion of theoretical topics and presentation of the projectwork.

Teaching tools

Copy of the trasparencies employed for lecturing. Basic mathematical models of electrical drives for numerical simulations.

Office hours

See the website of Domenico Casadei