Wavelet Transform-Based <sc>EMI</sc> Noise Mitigation in Power Converter Topologies

Abstract

This paper proposes a novel wavelet transform-based approach for electromagnetic interference (EMI) noise mitigation in power electronics topologies. The switching action of power semiconductor devices generates EMI in power converter modules which exceeds the noise limit set by the regulation of CISPR11. In order to cancel the EMI noise, the wavelet transform-based timefrequency localization approach has been used for generating a noise cancellation signal. The effectiveness of the proposed method has been evaluated in the terms of signal-to-noise ratio (SNR). Further, the effect of variance of the noise amplitude has been taken into consideration on the SNR. A relationship between the standard deviation, which is proportional to square root of the variance of the signal, and the SNR has been established. The proposed method has been implemented on the different power electronics topologies such as buck converter, boost converter, three-phase voltage source inverter, and Z-source inverter-based ac drive. The proposed method achieves the reduction of noise level below the safe limit set by CISPR11.Index Terms-Boost converter, buck converter, EMI, morlet wavelet, signal-to-noise ratio, three-phase voltage source inverter, wavelet transform, Z-source inverter.

Time–Frequency Analysis of Experimental Measurements for the Determination of EMI Noise Generators in Power Converters

“…As a result, detail is obtained on the frequency components of the signal in a time interval allowing a time-frequency "cross" localisation [25]. Unlike STFT, it is a multiresolution tool, i.e., by compressing or "stretching" the wavelet function (with a variable length window, if we use terms analogous to those of STFT), a compromise between temporal and frequency resolution is achieved for the entire spectrum.…”

“…However, obtaining the time signals is only the first step, as spectral analysis and performing this time-frequency correlation is not as immediate as it may seem at first glance due to the characteristics of the switching signal. The literature reports in [22][23][24][25] that it might not be enough to apply the Fourier transform in some of its implementations (such as the fast Fourier transform or FFT) to obtain the frequency response of the noise generators. These generators, together with the propagation paths, will allow the establishment of a model that links input and output.…”

Aggregated Conducted Electromagnetic Interference Generated by DC/DC Converters with Deterministic and Random Modulation

“…The shape of conducted EMI depends on the source of the interference as well as complex phenomena accompanying the flow of interference in circuits, including parasitic couplings. In the subject matter literature, some papers emphasize the necessity for assurance of reliable operation of complex energy systems and the need for EMC assurance [2][3][4][5][6][7][8]. Furthermore, some papers highlight how approaches concerning deterministic modulation (DetM) and random modulation (RanM), based on the parameters' control of fundamental switching frequency ( f sw ) and duty cycle (d), may contribute to achieving EMC requirements [9][10][11][12][13][14][15][16][17][18][19][20].…”

Investigations on EMI Mitigation Techniques: Intent to Reduce Grid-Tied PV Inverter Common Mode Current and Voltage

“…In [49], controllable devices are used and active filters are presented to suppress CMC generated by the CMV method, called the active noise cancellation scheme, in order to mitigate the noise signal [50]. In [51], a new wavelet transform-based technique to mitigate EMI noise in power converter is presented with a frequency band of 3-30 MHz.…”