Suppression of multiple power line harmonic interference for low frequency signals

Abstract

A novel and simple algorithm capable of extracting and cancelling harmonic disturbance from signals subject to severe power line interference is presented. The key element consists of the adaptation of a filter to a deterministic harmonic reference closely correlated to the interference. The resulting signal is optimal in the mean squared error sense. Simulation results show that this carefully crafted adaptive scheme can improve by up to 30 dB the signal to interference ratio. Minimal remaining interference and fast convergence are obtained by optimisation of the algorithm's parameters.Introduction: Several filter architectures have been proposed, whether adaptive [1, 2] or not [3], in order to eliminate the narrow-band low frequency power line interference (PLI) induced by the power grid. However, few models were proposed in the literature to treat multipleodd and even -harmonic distortion and that are capable of effectively tracking its variations. Such models could be used to process magneto-inductive (MI) radio communications highly distorted signals [4] and mitigate the PLI harmonic components. This Letter presents a recently developed method capable of estimating and extracting severe PLI harmonics in an adaptive fashion using a defined harmonic reference. The proposed method's performance is demonstrated and compared to the other performing method of Ziarani and Konrad [5].

Resistance‐to‐digital converter designed for high power‐line interference rejection capability

“…Similarly, the use of twisted cables ensures lower levels of magnetically coupled interference. Further, many existing resistance measurement schemes employ an analogue/digital filter to further suppress the 50/60 Hz interference in the measurement signal [17][18][19]. On the other hand, RDCs possess either zero or limited inherent interference rejection capabilities [20].…”