Harmonicˋs Study, recommendations & solutions


By drawing current in a non-linear or non-sinusoidal manner, the VFDs and electronics loads can introduce excessive levels of both current and voltage harmonics. Non-linear loading on marine vessels can now reach 80% of the onboard electrical generating capacity and result in total harmonic voltage distortion (THDv) over 30%. All marine classification bodies are extremely concerned about high harmonic voltage distortion and its consequences including critical items of equipment malfunction or failure. Often viewed by SOLAS (Safety Of Life At Sea) as a potential issue, classification bodies have imposed strict limitations on the magnitude of harmonic voltage distortion permitted on vessels classed under their rules. Any vessels seeking classification are now being required to demonstrate compliance with these standards.
Steps to follow:
· Recompilation of data: Every feature of each electric element should be provided.
· Measurement in a proper spot of the installation: It is necessary to spend some time, on-site, to check and measure current and voltage distortion. 
· Analysis: Once gathering the information and modeling the system on the computer, possible solutions will show up. 
· Installation of some of the following equipment: After the analysis, we propose different actions to mitigate the distortion. Installations of active filters, passive filters, in-line reactor, VFDs, or selection of the correct cable, would be part of the solution.