Applying harmonic standards to time-varying harmonics

This paper discusses the need to develop a set of limits for measured or time-varying harmonics. A few methods used or proposed to address this problem have been discussed. All methods share the principle that if the harmonic distortion level is high, a system is expected to have less tolerance on it and, consequently, only shorter duration for the distortion is permitted. The difference is on how to implement the principle. The subject matter is still evolving and further research activities are encouraged.