Harmonic Distortion Correction
Our Harmonic Distortion Correction Services
Power Survey provides solutions that mitigate undesirable levels of harmonic distortion in industrial and commercial customer facilities.
Our engineers will conduct an in-depth harmonic network analysis using ETAP software to assess:
- Harmonic charges
- Resonant frequency of your network
- Design optimization
Harmonic Mitigation Products
Following analysis and assessment, we will provide turn-key solutions involving these products:
- Power Factor Capacitors Designed to Handle Harmonic Distortion:
All Power Survey capacitors are designed to handle harmonic currents; however, we also offer capacitors custom-designed for systems with high harmonic distortion. If you have a harmonic-reach application, our high-harmonic capacitors will provide a more robust construction compared to using standard capacitors in the same application.
- Passive Harmonic Filters:
We manufacture a passive harmonic filter. The filter creates an “anti-harmonic” at selected harmonic frequencies that significantly reduces the harmonic currents at those frequencies. This filter can be included in your capacitor bank solution.
We offer an active harmonic filter (AHF) that automatically determines the existence of harmonic currents across the frequency spectrum and creates “anti-currents” to reduce the harmonics to acceptable levels. Unlike the passive filters, they do not require a pre-study of the circuit’s harmonic currents to affect the design of the filters.
We will design your harmonics solution, provide recommendations on the necessary products, and install the products on-site.
Problems Resulting from Harmonic Distortion
Harmonic distortion can increase the voltage and current in power systems, resulting in overheating. This reduces the system power factor, causes equipment degradation, and results in less usable power and potential penalties on monthly utility bills.
Higher frequency harmonics can also cause core losses in motors and equipment malfunctions due to excessive voltage distortion – for example false tripping of branch circuit breakers. If left unchecked, increased temperatures and interference can greatly shorten the life of electronic equipment and damage power systems.
Under thermal overload, power factor capacitors’ fuses blow. This is why capacitors provide an early warning signal that harmonic currents exist in the facility.
What Is Harmonic Distortion and Harmonic Distortion Correction?
Harmonic distortion is the interference in an AC power signal created by frequency multiples of the sine wave. Total Harmonic Distortion (THD) is used as a measure of the amount of harmonic distortion in the system, and should be less than 5%.
The non-linear characteristics of many industrial and commercial loads such as power converters, fluorescent lamps, computers, light dimmers, and variable speed motor drives (VSDs) used in conjunction with industrial pumps, fans, compressors, and air conditioning equipment have made harmonic distortion a common occurrence in electrical power networks. Further, large industrial converters and variable speed drives can generate significant levels of distortion at the point of common coupling (PCC), where other users are connected to the network.
Without proper protection, these harmonics can affect other parts of the plant and even the grid.
The existence of harmonic currents is a site-specific problem, resulting from the complex interrelationship between all of the electrical electronic equipment in a facility and is therefore difficult to predict and model. If your total VSD connected horsepower is greater than 20% of the total load, your facility likely has harmonics issues.
Harmonic distortion can be reduced (corrected) by:
- Avoiding odd-number harmonics: 5, 7, 11, and 13
- Using size reactors to filter site-specific harmonic problems
- Using proper filtering and chokes
It’s possible for non-linear equipment and power capacitors to co-exist. You don’t have to give up the benefits of power correction if your facility uses many types of electronic power controls and computers!