Electrical Motor Control, Trouble shooting Techniques

Overview

Course Outline

Day One

Fundamentals of Electric Systems

• • Capacitors
  • Current and Resistance
  • The Magnetic Field
  • Faraday’s Law of Induction
  • Lenz’s Law
  • Inductance
  • Alternating Currents
  • Three-Phase System

  Introduction to Machinery Principles

  • Electric Machines and Transformers
  • Common Terms and Principles
  • The Magnetic Field
    • Production of a Magnetic Field
  • Magnetic Behavior of Ferromagnetic Materials
    • Energy Losses in a Ferromagnetic Core
  • Faraday’s Law – Induced Voltage From a Magnetic Field Changing with Time
  • Core Loss Values
  • Permanent Magnets
  • Production of Induced Force on a Wire
  • Induced Voltage on a Conductor Moving in a Magnetic Field

  Day Two

  AC Machine Fundamentals

  • The Rotating Magnetic Field
    • Proof of The Rotating Magnetic Field Flux Concept
    • The Relationship between Electrical Frequency and The Speed of Magnetic Field Rotation
    • Reversing The Direction of the Magnetic Field Rotation
    • The Induced Voltage in AC Machines
      • The Induced Voltage in a Coil on a Two-Pole Stator
      • The Induced Voltage in a Three-Phase Set of Coils
      • The RMS Voltage in a Three-Phase Stator
    • The Induced Torque in a Three-Phase Machine
    • Winding Insulation in AC Machines
    • AC Machine Power Flow and Losses

  Induction Motors

  • Induction Motor Construction
  • Basic Induction Motor Concepts
    • The Concept of Rotor Slip
    • The Electrical Frequency of the Rotor
  • The Equivalent Circuit of an Induction Motor
    • The Rotor Circuit Model
  • Losses and The Power-Flow Diagram
  • Induction Motor Torque-Speed Characteristics
    • Comments on The Induction Motor Torque-Speed Curve
    • Variation of The Torque-Speed Characteristics
  • Control of Motor Characteristics By Squirrel-Cage Rotor Design
    • Deep Bar and Double-Cage Rotor Designs
  • Starting Induction Motors
    • Induction Motor Starting Circuits

  Day Three

  Maintenance of Motors

  • Characteristics of Motors
  • Enclosures and Cooling Methods
  • Application Data
  • Design Characteristics
  • Insulation of AC Motors
  • Failures in Three-Phase Stator Windings
  • Predictive Maintenance
  • Motor Troubleshooting
  • Diagnostic Testing for Motors
    • Stator Insulation Tests
    • DC Tests For Stator and Rotor Windings
    • Insulation and Polarization Index
    • Test Setup and Performance
    • Interpretation
    • DC High-Potential (Hipot) Testing
    • Surge Testing
    • Terminal-to-Terminal Resistances (winding resistances)
    • Tests for the Detection of Open Circuits in Induction Motor Cage Windings
    • Stator Current Fluctuation Test
    • Manual Rotation Test
  • Repair and Refurbishment of AC Induction Motors
    • Stator Work
    • Rotor Work
    • Bearings
    • Oil and Water Heat Exchangers
    • Temperature Detectors
    • Motor Repair
    • Motor Rewind
  • Failures in Three-Phase Stator Windings
  • Case Study 1: Rewinding of Motors; to show the participants how the motors been rewind. Also to let the participants to do by them selves the rewinding of most types of motors.

  Day Four

  Synchronous Machines

  • Physical Description
  • Pole Pitch: Electrical Degrees
  • Airgap and Magnetic Circuit of a Synchronous Machine
  • Synchronous Machine Windings
  • Field Excitation
    • Rotating Rectifier Excitation
    • Series Excitation
  • No-Load and Short-Circuit Values
  • Torque Tests
    • Speed-Torque Characteristic
    • Pull-In Torque
    • Pull-Out Torque
  • Excitation of a Synchronous Machine
  • Machine Losses
    • Windage and Friction Loss
    • Core Losses
    • Stray-Load Loss
    • Armature Conductor Loss
    • Excitation Loss

  Day Five

  Speed Control of Induction Motors

  • Speed Control by Changing the Line Frequency
    • 2.0 Speed Control by Changing the Line Voltage
    • 3.0 Speed Control by Changing the Rotor Resistance
    • 4.0 Solid-State Induction Motor Drives
    • 5.0 Motor Protection
    • 6.0 The Induction Generator
  • Induction Generator Operating Alone
    • 7.0 Induction Motor Ratings

  Vibration Analysis

  • The Application of Sine Waves to Vibration
  • Multimass Systems
  • Resonance
  • Logarithms and Decibels (db)
  • The Use of Filtering
  • Vibration Instrumentation
  • Displacement Transducer (proximity probe)
  • Velocity Transducer
  • Acceleration Transducer
  • Transducer Selection
  • Time Domain
  • Frequency Domain
  • Machinery Example
  • Vibration Analysis
  • Vibration Causes
  • Forcing Frequency Causes
  • Unbalance
  • Misalignment
  • Mechanical Looseness
  • Bearing Defects
  • Gear Defects
  • Oil Whirl
  • Blade or Vane Problems
  • Electric Motor Defects
  • Uneven Loading
  • Drive-Shaft Torsion
  • Resonant Frequency
  • Vibration Severity