EMI mitigation in switching power converters combining closed‐loop gate drive and chaotic frequency modulation technique

Abstract

All switching power converters are characterised by inevitable switching actions with relevant interference emissions. The voltage and current transients of power metal oxide semiconductor field effect transistor (MOSFET)/insulated-gate bipolar transistor are the main sources in switching power converters for both conducted and radiated emissions. In this study, a promising electromagnetic interference (EMI) mitigation method combining the closed-loop gate drive method and the chaotic switching frequency modulation technique is demonstrated for switching power converters. A chaotic pulse-width modulation waveform with Gaussian S-shape switching transients was proposed to achieve remarkable reduced EMI generation at all frequencies. Spectral characteristics of this new switching waveform were investigated by the power spectral density to verify the feasibility of reduced EMI generation. A closed-loop gate controller was presented to shape the switching transients of power MOSFET into the proposed switching waveform. Circuit tests were carried out in both simulations and experiments. The results validated that the proposed method could achieve remarkable EMI mitigation in switching power converters.

Recent Contributions, Future Prospects and Limitations of Interlinking Converter Control in Hybrid AC/DC Microgrids

“…EMI is referred to as radiated interference and conducted interference [210], whereas the latter is the focus of this part. High-frequency EMI is one source of pollution to the main grid that should comply with the Electro-Magnetic Compatibility (EMC) of nearby devices [211], [212].…”

EMI filter design for single‐phase grid‐connected inverter with noise source impedance consideration

“…Wide bandgap semiconductors such as silicon carbide (SiC) and gallium nitride, which are characterised by high switching speeds, are being widely used in power converters to achieve greater efficiencies and higher power densities. However, the high voltage transition rate (d v/ d t ) and high current transition rate (d i/ d t ) result in more serious electromagnetic interference (EMI) issues [1–5], which may affect the system safety and reliability. Therefore, power converters should fulfil the regulatory electromagnetic compatibility standards.…”

Analysis and design of an asynchronous pulse‐width modulation technique for switch mode power supply

“…This causes the output signal to produce the undesired harmonic tones that, in turn, raises the power supply noise and also electromagnetic interference (EMI) emission. EMI is coupled into all the circuits that are supplied with the switchedmode power supply (SMPS) [4][5][6][7][8][9][10] and/or nearby circuitries. The acceptable levels of the generated EMI are different for different applications as well as the desired frequency range [8][9][10][11].…”

“…Thus, to ensure high-quality output, a higher-order LPF [12] must be applied at the output of the power supply. However, it is worsening the dynamic performance [12], complicates the design, and is not cost-efficient either [7][8][9][10][11][12][13].…”

“…EMI is coupled into all the circuits that are supplied with the switched‐mode power supply (SMPS) [4–10] and/or nearby circuitries. The acceptable levels of the generated EMI are different for different applications as well as the desired frequency range [8–11]. Unfortunately, the output low‐pass filter (LPF) does not completely suppress these harmonic tones.…”