AC motors are essential to a wide range of industries, powering small, medium, and large-scale applications. It's estimated that over 50% of global energy consumption is converted into work by AC motors, which are controlled by drives. These drives are becoming progressively more advanced and electrical, and their operation and monitoring can now be integrated into a plant’s SCADA system. Gaining a comprehensive understanding of maintenance and troubleshooting for such critical industrial equipment results in reduced downtime and enhanced productivity for companies. Additionally, ensuring the proper protection mechanisms and their integration into the system safeguards these costly assets from failure, while also enhancing the safety of operations personnel. This Variable Speed-Drive Troubleshooting training course covers these key aspects for both AC motors and their associated drives.
The objectives of this Variable Speed-Drive Troubleshooting training course are:
- To explain the operation and design of AC electrical motors and drives using advanced inverter technology, focusing on how to match their characteristics with those of the loads they drive.
- To review established industrial standards and procedures for maintaining both motors and drives.
- To demonstrate troubleshooting techniques for both motors and drives, utilizing manufacturer-developed methodologies to significantly reduce downtime.
- To provide hands-on experience with single-line diagrams and other relevant documentation, enabling effective commissioning, maintenance, and troubleshooting.
- To discuss case studies and share practical insights to enhance learning from real-world experiences.
The latest educational methods and strategies will be employed. The Energy training course is designed to maximize delegate benefit from the outset and any specific goals of each participant will be discussed to ensure needs are fulfilled as far as possible. Questions are encouraged throughout the day and at the daily wrap-up sessions. This provides opportunities for participants to discuss with the presenter and other delegates specific problems and appropriate solutions.
All delegates take away a detailed and comprehensive copy of the material presented; therefore, minimal note taking is encouraged to ensure maximum participation and attention.
Variable speed drive and troubleshooting is intended for:
- Electrical engineers
- Technicians and plant operations and maintenance professionals
- Team leaders and professionals in maintenance engineering departments
- Anyone who wishes to update their knowledge on one of the most important equipment combination, i.e. motor/drive and how to get the best of their trouble-free operation in the plant if possible
Day One: AC Motors
- Fundamentals of rotating machines theory, rotor types, rotor slip and principles of operation, equivalent circuit, torque-speed characteristics
- Three phase induction motors types, construction, principle of operation, characteristics and applications
- Three phase synchronous motors construction and characteristics
- Starting of induction motors and associated techniques, accelerating and soft starters
- Speed control requirements of AC motors and load matching
- Medium voltage three phase induction motors
Day Two: Drives-Introduction
- Variable speed drive motors verses general purpose motors, VSD selection
- Reasons and advantages of variable speed drives, DC drive and AC drive comparisons, VFD curves and tests
- Variable speed drives basic theory, voltage source inverter, current course inverter and pulse width modulation
- Variable speed drives disadvantages, harmonics mitigation
- Choosing the best variable frequency drives and installation considerations
- Variable speed drives parameter programming and applications
Day Three: Drives Fundamentals
- Basic principles of AC Variable-Speed Drives (VSD's), constant torque region, constant power (extended speed) region, four quadrant operation
- Power semiconductors, diode, thyristor (SCR), IGBT, MOSFET, GTO and others
- Inverters, voltage-source and current-source, pulse width modulated (PWM) inverters
- Operations of DC link energy and inverters, regeneration or dynamic slowdown, dynamic breaking, plugging
- PWM waveforms and analysis, effects of PWM on motor bearings and insulation and life expectancy, volts/Hertz control, start up and operation, dynamics, PWM rectifier inverter systems
- Switching transients, harmonics and power factor
- AC drive line power factor, insulation voltage stress, electromagnetic interferences (EMI), EMI filtering, VFD shielded cables
Day Four: Troubleshooting and Maintenance of Drives
- Variable speed drives generic troubleshooting techniques
- Variable speed drives modes of operations, converter failures, common failure modes
- Variable speed drives motor bearing maintenance
- Testing and identification of failed thyristor and diode
- Test instruments and VSD analysers
- Preventative maintenance, approaches, guidelines and scheduling, checking, dynamic and static inspections, detecting phase unbalances, loss of phases, and phase reversal
Day Five: Protection of Motors and Drives
- Protection of AC motors, requirements, overload protection, Numerical relays for motor and drives protection
- VFD motor problem areas, voltage on shaft, shaft induced current
- Variable speed drives modular design and maintenance
- Methods of preventing bearing failures in VSDs
- Protection of inverters and electronic converters driving motors
- Medium voltage variable speed drives and protection
