The HARMONIC CALCULATOR provides a tool for determining how much voltage and current distortion might exist on your distribution system when operating non linear loads. This program is not intended to determine harmonic distortion with single phase loads.
The analysis with single phase load is quite different from analyzing a 3 phase ac motor circuit. For single phase circuits, a distorted current wave form can place more stress on the supply system. For a 3 phase motor circuit converted to variable speed, the distorted current wave form does not place more stress on the supply system if the reactive component of current is removed.
Only PWM AFDs eliminate the reactive current component. For a given motor, the electrical system stress is less with the motor operating on a PWM AFD as compared against operating the motor across the line. For additional information about how to correctly measure current distortion for AFDs, refer to the article about: Measuring Current Distortion
This program is intended to provide an estimate on harmonic conditions that might exist when applying non linear equipment which controls ac motors. It does not replace the need to determine base line conditions or an evaluation of a complete electrical system. The program does not determine the existing harmonic conditions, only an estimate of what additional distortion could be likely. Refer to disclaimer within program.
This program is designed to provide an estimate of harmonic distortion and is not intended as an exact power system analysis tool. It is generally accepted that no analysis program can provide an exact representation of an electrical distribution system and that exact values for harmonic distortion can only be determined in the actual installation with all equipment operating.
These programs are provided free of charge to be used as intended. These are for estimations only, and the results are not guaranteed to be accurate. By using the following, you agree to relieve Rockwell Automation or any associated company of any liability or damages caused by direct or indirect use of these programs. They are provided as a convenience to you, our customer.