The water industry requires a reliable solution for securing the flow of water and wastewater. Pumping and aeration systems are integral parts of a reliable solution and these systems consume a considerable amount of energy. This energy consumption can be substantially reduced when variable frequency drives (VFDs) are properly introduced into these systems.
VFDs, along with many other types of electronics, cause a phenomenon known as power line harmonics. The advantages of using a VFD far outweigh the negative effects of harmonics, but it is important to be aware of harmonics, the potential problems they can cause, and the solutions that are available to mitigate those harmonics.
While this paper focuses on VFDs as a source of harmonics, it is important to note that VFDs are not the only source of harmonics in a system. However, VFDs are often the focus of harmonic calculation and mitigation conversations due to the fact that VFDs in water applications may make up a significant portion of the overall power consumption. Examples of VFDs in water and wastewater applications include pumps, blowers, compressors, digesters and conveyors.