This page covers the VFD overview. From power electronics to control systems to motor theory.. These are topics that have been brought up during design, installation and troubleshooting drive systems over the past 8 years.
Topics listed without a link are yet to be written. : ) I’ll get there, hopefully at a rate of one a week…
Drive ( and some Motor) Theory:
What is a Variable Frequency Drive?
Input rectifier stage
3 phase power fundamentals
Types of input rectifiers
Filtering- types and effects
6 pulse ,12 pulse and 18 pulse VFD
DC bus- What is the DC bus – Types of capacitors and other components
Output/Inverter Stage
Switching frequencies and its effects
When does regeneration onto the VFD DC bus occur?
Variable Speed Drive, Speed, Torque and Power
Drive applications:
Choosing between VFD’s and Soft Starts
Constant Torque VFD Applications – What happens to voltage, current and power?
Corner grounded systems and its effects on VFD’s
Efficiency of a VFD
Harmonic distortion – power factor, and the effect of capacitors and inductance
PM synchronous vs. AC induction motors
Noise issues visualized
LTSpice simulation setup for VFD
Effects of cable length on a drive installation
Submersible pumps
Abnormal sounds from a motor driven by a drive
Variable and constant torque
Power factor on a drive installation
Setting up a drive for pump applications
Submersible pumps and drives- always check drive trip history if there are issues
Line/Load Reactors and Filters
Why is the line reactor noisy?
Can a 3 phase drive run a single phase motor?
Drive Control:
Potentiometer wiring
Sink and source logic inputs and outputs
