There are a variety of ways to mitigate harmonics caused by variable frequency drives (VFDs). After a quick overview on harmonics, IEEE 519, and an assortment of mitigation techniques, this video focuses on comparing an Active Front End (AFE) drive to an Active Filter (AF) strategy. AFE drives are considered a decentralized mitigation strategy, and the harmonics are taken care of at the VFD. In HVACR applications, Active filters are most often applied in a centralized mitigation strategy and the harmonics are taken care of at one point in the system. Both strategies have their own unique advantages. After this video an Engineer will have a better understanding of when to apply which strategy.
See these other videos for more information on harmonics and mitigation techniques.
AFE vs passive filter: https://youtu.be/8qKapfOjYNE
00:00 Introduction
01:00 How a VFD creates harmonics
04:10 Terminology
04:45 IEEE 519
07:55 Harmonic mitigation techniques
10:15 No mitigation
11:50 Chokes
13:03 18-pulse
15:48 Passive filter
17:43 Active solutions
18:19 Active front end (ULH)
21:22 Active filter
26:44 AFE vs AF comparison
33:49 Strategy with examples
42:40 Tie breaker example
46:09 AFE vs AF analogy
47:42 Harmonic mitigation strategy
51:32 Responsibility analogy
53:55 Physical size comparison
56:07 Summary
