Design of Electric Machines
This course teaches the design process for electric motors and generators based upon fundamental therories. It supplements electric machine theory for advanced courses in electric machines.
Objectives
- A thorough knowledge of the design procedures in design of the electric machines.
- Get a general idea on topics like mechanical, manufacturing and future challenges for machine design.
Textbooks
Design of Brushless Permanent-Magnet Motors Get access Arrow
J R Hendershot, TJE Miller · Oxford Science
Modules
Description: Introduction to the history of electric machines and an overview of the course scope, covering the evolution of motor technology and fundamental design principles.
Description: Foundational theory of electromechanical energy conversion, explaining the physics behind how motors and generators operate.
Description: Overview of power electronics used to drive machines, focusing on three-phase inverters and control strategies for different machine types.
Description: Outlines the step-by-step engineering workflow for designing an electric machine, from specifications to final prototyping.
Description: Methodologies for determining the initial physical dimensions of a machine based on torque and power requirements.
Description: Detailed analysis of various loss mechanisms in motors, including copper, iron (core), friction, and windage losses.
Description: Comparison of traditional analytical sizing calculations versus modern Finite Element Analysis (FEA) for magnetic simulation.
Description: Discussion on key performance metrics such as efficiency maps, torque-speed envelopes, and thermal limits.
Description: Study of soft and hard magnetic materials, including electrical steels and permanent magnet grades (Neodymium, Ferrite).
Description: Guidelines for selecting the optimal combination of pole counts and slot numbers to minimize cogging torque and noise.
Description: Criteria for designing the stator geometry to optimize flux path and structural integrity.
Description: Deep dive into lamination stacking, material selection, and stacking factors for the stator core.
Description: Analysis of insulation materials, classes, and failure modes related to voltage stress and thermal cycling.
Description: Fundamentals of winding layout, including coil span, pitch, and connection diagrams.
Description: Advanced winding techniques, including distributed vs. concentrated windings and their effect on machine performance.
Description: Introduction to the most common industrial motor, the squirrel-cage induction machine.
Description: Detailed theory of operation for induction machines, including rotating magnetic fields and torque production.
Description: Strategies for designing induction machines to meet specific load requirements like starting torque and efficiency.
Description: Derivation of the induction motor equivalent circuit and analysis of torque-speed characteristics.
Description: Design of the rotor structure for induction machines, focusing on bar materials and shapes.
Description: Continued analysis of induction motor rotors, dealing with skewing and harmonic reduction.
Description: Analyzing how Variable Frequency Drives (VFD) and inverters affect the performance and losses of induction motors.
Description: Introduction to synchronous reluctance motors, which generate torque via magnetic saliency rather than magnets.
Description: Theoretical framework for RSM, defining the d-q axis inductances and torque equations.
Description: Design techniques for RSM rotors, specifically flux barrier geometry to maximize the saliency ratio.
Description: Evaluating the efficiency, power factor, and torque ripple of Reluctance Synchronous Machines.
Description: Distinction between BLDC (trapezoidal back-EMF) and PMAC (sinusoidal back-EMF) machines.
Description: Design theory for Surface Permanent Magnet (SPM) and Interior Permanent Magnet (IPM) rotors.
Description: Mechanical and magnetic design constraints for PM rotors, including magnet retention and demagnetization protection.
Description: Calculation of torque, speed, and efficiency for permanent magnet machines.
Description: Deep dive into the motor constants Kt (Torque) and Ke (Back-EMF) and their relationship to performance.
Description: Design considerations specifically for PM generators used in wind turbines and backup power.
Description: Fundamentals of thermal management in electric machines, including heat generation and transfer paths.
Description: Overview of cooling methods such as natural convection, forced air, liquid cooling, and oil spray.
Description: Mechanical engineering aspects of motor design, including housing, bearings, and vibration analysis.
Description: Insight into the manufacturing processes for electric machines, including coil winding, impregnation, and assembly.