Improving 9-150 kHz EMI Performance of Single-Phase PFC Rectifier

In order to improve the Electromagnetic Interference (EMI) performance of grid-connected power electronics converters within the new 9-150 kHz frequency range, this digest investigates feasible solutions through modifying the EMI filter and applying spectral shaping method. The proposed solutions are validated based on a 1 kW single-phase Power Factor Correction (PFC) rectifier prototype. Moreover, frequency domain modeling approach is utilized as a virtual-oriented methodology in order to analyze the converter behavior and provide fast prototyping.</p

An EMI characterization and modeling study for consumer electronics and integrated circuits

“As internet-of-things (IoT) applications surge, wireless connectivity becomes an essential part of the network. Smart home, one of the most promising application scenarios of IoT, will improve our life quality enormously. However, electromagnetic interference (EMI) to the receiving antenna, either from another electronic product or from a module/an integrated circuit(IC) inside the same wireless device, will degrade the performance of wireless connectivity, thus influencing the user experience. Characterization and modeling of the EMI become increasingly important. In the first part, an improved method to extract equivalent dipoles from magnitude- only electromagnetic-field data based on the genetic algorithm and back-and-forth iteration algorithm is proposed. The method provides an automatic flow to extract the equivalent dipoles from electromagnetic-field data on arbitrarily shaped scanning surfaces and minimizes the number of extracted dipoles. In the second part, both the differential mode (DM) and common mode (CM) EMI below 1 MHz from the ac-dc power supply in a LED TV is analyzed and modeled. Through joint time-frequency analysis, the drain-to-source voltage of the power MOSFET in the power factor correction (PFC) converter is identified as the dominant noise source of both CM and DM EMI below 1 MHz from the power supply. The current paths of DM and CM EMI are explained and modeled by a linear equivalent circuit model. In the last part, the noise source and current path of the conducted CM EMI noise from a Qi-compliant wireless power transfer (WPT) system for mobile applications are analyzed. The analysis and modeling explain the mechanism of the CM EMI noise and provide guidelines to reduce the CM EMI noise”--Abstract, page iv

Closed-loop impedance modeling and analysis of three-phase active rectifier below 150 kHz frequency range

This paper derives the closed-loop impedance model for the typical three-phase active rectifier and investigates the dominant factors influencing the converter impedance below 150 kHz frequency range from the basic performance (e.g., steady-state and dynamic performance) and EMI perspectives. Therefore, the complete modeling process of the closed-loop impedance is described, including the control analysis and impedance modeling. The discussion of improving basic performances and EMI performance for the power converter is proposed. Moreover, an advanced impedance measurement technique is introduced. Finally, the validation of the derived closed loop impedance model and the dominant influence analysis for the three-phase rectifier are carried out in MATLAB and PLECS