Electric Motors and Drives: Index

1. ELECTRIC MOTORS: Introduction

• Introduction
• Producing Rotation
  • Magnetic field and magnetic flux
  • Magnetic flux density
  • Force on a conductor
• Magnetic Circuits
  • Magnetomotive force (MMF)
  • Electric circuit analogy
  • The air-gap
  • Reluctance and air-gap flux densities
  • Saturation
  • Magnetic circuits in motors
• Torque Production
  • Magnitude of torque
  • The beauty of slotting
• Specific Loadings and Specific Output
  • Specific loadings
  • Torque and motor volume
  • Specific output power – importance of speed
• Energy Conversion – Motional EMF
  • Elementary motor – stationary conditions
  • Power relationships – conductor moving at constant speed
• Equivalent Circuit
  • Motoring condition
  • Behavior with no mechanical load
  • Behavior with a mechanical load
  • Relative magnitudes of V and E, and efficiency
  • Analysis of primitive motor – conclusions
• General Properties of Electric Motors
  • Operating temperature and cooling
  • Torque per unit volume
  • Power per unit volume – importance of speed
  • Size effects – specific torque and efficiency
  • Efficiency and speed Rated voltage
  • Short-term overload
  • Review Questions

2. POWER ELECTRONIC CONVERTERS FOR MOTOR DRIVES

• Introduction
  • General arrangement of drives
• Voltage Control – DC Output from DC Supply
  • Switching control Transistor chopper
  • Chopper with inductive load – overvoltage protection, Features of power electronic converters
• DC from AC – Controlled Rectification
  • The thyristor Single-pulse rectifier
  • Single-phase fully controlled converter – output voltage and control 3-phase fully controlled converter, Output voltage range, Firing circuits
• AC from DC SP – SP Inversion
  • Single-phase inverter Output voltage control Sinusoidal PWM 3-phase inverter
  • Forced and natural commutation – historical perspective Matrix converters
• Inverter Switching Devices
  • Bipolar junction transistor (BJT) Metal oxide semiconductor field effect transistor (MOSFET) Insulated gate bipolar transistor (IGBT) Gate turn-off thyristor (GTO)
• Converter Waveforms and Acoustic Noise
• Cooling of Power Switching Devices
  • Thermal resistance
  • Arrangement of heatsinks and forced air cooling Cooling fans
• Review Questions

3. CONVENTIONAL DC MOTORS

• Introduction
• Torque Production
• Function of the commutator
• Operation of the commutator – interpoles
• Motional E.M.F.
• Equivalent circuit
• DC motor – Steady-State Characteristics
• No-load speed
• Performance calculation – example
• Behavior when loaded
• Base speed and field weakening
• Armature reaction
• Maximum output power
• Transient Behavior – Current Surges
• Dynamic behavior and time-constants
• Shunt, Series and Compound Motors
• Shunt motor – steady-state operating characteristics
• Series motor – steady-state operating characteristics
• Universal motors
• Compound motors
• Four-Quadrant Operation and Regenerative Braking
• Full speed regenerative reversal
• Dynamic braking
• Toy Motors
• Review Questions

4. DC MOTOR DRIVES

• Introduction
• Thyristor DC Drives – General
  • Motor operation with converter supply
  • Motor current waveforms
  • Discontinuous current
  • Converter output impedance: overlap
  • Four-quadrant operation and inversion
  • Single-converter reversing drives
  • Double SP-converter reversing drives
  • Power factor and supply effects
• Control Arrangements for DC Drives
  • Current control
  • Torque control
  • Speed control
  • Overall operating region
  • Armature voltage feedback and IR compensation
  • Drives without current control
• Chopper-Fed DC Motor Drives
  • Performance of chopper-fed DC motor drives
  • Torque–speed characteristics and control arrangements
• DC Servo Drives
  • Servo motors
  • Position control
• Digitally Controlled Drives
• Review Questions

5. INDUCTION MOTORS – ROTATING FIELD, SLIP AND TORQUE

• Introduction
• Outline of approach
• The Rotating Magnetic Field
• Production of rotating magnetic field
• Field produced by each phase winding
• Resultant field
• Direction of rotation
• Main (air-gap) flux and leakage flux
• Magnitude of rotating flux wave
• Excitation power and VA
• Summary
• Torque Production
• Rotor construction
• Slip
• Rotor induced emf, current and torque
• Rotor currents and torque – small slip
• Rotor currents and torque – large slip
• Influence of Rotor Current on Flux
• Reduction of flux by rotor current
• Stator Current-Speed Characteristics
• Test Questions