Electromagnetic Interference Modeling Research Articles

Modeling, Analysis and Mitigation of Radiated EMI Due to PCB Ground Impedance in a 65 W High-Density Active-Clamp Flyback Converter

This paper first reviewed the modeling and prediction techniques for the radiated electromagnetic interference (EMI) in active-clamp Flyback (ACF) power converters. An improved radiated EMI model was then developed including the PCB ground impedance based on the ACF converter under investigation. Next, the improved radiated EMI model was quantified and experimentally verified. Two mitigation techniques were developed for the radiated EMI based on the improved model. Experiments were conducted to verify the developed analysis and mitigation techniques for the radiated EMI. The proposed modeling and mitigation techniques were finally extended to other isolated power converter topologies.

A Review of EMI Research of High Power Density Motor Drive Systems for Electric Actuator

With the global attention given to energy issues, the electrification of aviation and the development of more electric aircraft (MEA) have become important trends in the modern aviation industry. The electric actuator plays multiple roles in aircraft such as flight control, making it a crucial technology for MEA. Given the limited space available inside an aircraft, the power density of electric actuators has become a critical design factor. However, the pursuit of high power density results in the need for larger rated power and higher switching frequency, which can lead to severe electromagnetic interference (EMI) issues. This, in turn, poses significant challenges to the overall reliability of the electric actuator. This paper provides a comprehensive review of EMI in high power density motor drive systems for electric actuator systems. Firstly, the state of the art of electric actuator systems are surveyed, pointing out the contradictory relationship between high power density and EMI. Subsequently, various EMI modeling approaches of motor control systems are reviewed. Additionally, the main EMI suppression methods are summarized. Active EMI mitigation methods are emphasized in this paper due to their advantages of higher power density compared with passive EMI filters. Finally, the paper concludes by summarizing the EMI research in motor drive systems and offering the prospects of electric actuators.

Modeling and Prediction of Common Mode Electromagnetic Interference in GaN-Based Switching Power Converters

Behavioral models of common mode (CM) electromagnetic interference (EMI) are proposed herein for a GaN high-electron-mobility transistor (HEMT) synchronous buck converter. First, a CM noise model is developed using a linear equivalent circuit that consists of a voltage source, current source, and two noise impedances. The behavioral parameters of the CM model are then extracted by changing the input-side shunt impedances. A GaN HEMT buck converter setup is then built using switching frequencies of 100 kHz, 200 kHz, and 500 kHz to verify the validity of the CM EMI behavioral model. A comparison between the experimental and predicted results indicated that the proposed CM EMI model of GaN-based power converters was able to predict well the CM EMI current in the 150 kHz–30 MHz frequency range.

Advances in Modeling and Suppression Methods of EMI in Power Electronic Converters of Third-Generation Semiconductor Devices

With the development of high-frequency, miniaturized, and lightweight power electronic devices, third-generation semiconductor devices are more and more used in the main circuits of power electronic converters. The electromagnetic interference (EMI) generated by their fast switching can affect the performance of power electronic converters. Therefore, it is necessary to investigate the modeling and suppression methods of conducted noise in power electronic converters of third-generation semiconductor devices. This paper describes the EMI sources and coupling paths of EMI in third-generation semiconductor devices used in power electronic converters. The modeling methods of EMI are summarized from the perspectives of power devices and coupling paths. The suppression methods of conducted noise are summarized by suppressing EMI sources and improving coupling path characteristics. This paper provides a reference for the electromagnetic compatibility design of power electronic converters for third-generation semiconductor devices.

Electromagnetic interference modeling and elimination for a solar/hydrogen hybrid powered small-scale UAV

The trajectory related and Direct Current (DC) Electromagnetic Interference (EMI) of lithium battery, fuel cell and photovoltaic modules has a great influence on the small-scale Unmanned Aerial Vehicle (UAV) airborne magnetometer and is hard to be shielded, calibrated or filtered. Besides, the mechanisms underlying the DC EMI have been rarely investigated yet. To cope with this problem, this paper systematically studies the EMI models, and proposes an online 3-layer EMI reduction scheme. First, EMI coupled with UAV motion model and hybrid power system is established. Second, the mechanism EMI models of hybrid power system are established and verified based on the proposed concept “equivalent current”. Third, an online 3-layer EMI reduction scheme is proposed, including battery layer, trajectory planning layer and energy management layer. In the first main layer, EMI self-cancellation is realized by rotating battery inclinations and symmetrical circuits. In response to errors, the trajectory planning layer reduces the EMI intensity by optimizing an optimal trajectory, while the energy management layer prioritizes power allocation to power sources that can produce small and stable EMI. Simulation results of climb, level flight and descent illustrate the efficaciousness and applicability of the proposed online 3-layer EMI reduction scheme.

Submodule Switching-State Based EMI Modeling and Mixed-Mode EMI Phenomenon in MMC

Modular multilevel converter (MMC) is widely used in high-voltage occasions for its good power qualities and flexible controls. However, the large number of semiconductor switches would lead to an extremely complicated electromagnetic environment. To clarify the detailed conducted electromagnetic interference (EMI) mechanisms of MMC, this article builds an EMI model of MMC considering different submodule switching states. Based on this model, the EMI paths of submodule switching- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> and switching- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> processes are analyzed. Then, this article analyzes the effects of submodule heatsink connecting patterns on EMI, and explains the mechanisms of mixed-mode (MM) EMI phenomenon that common-mode component brings in extra differential-mode component. Simulation and experiment results verify the proposed EMI mechanisms and MM phenomenon. The conclusions of this article have great reference significance for the EMI research of MMC and other high-voltage converters.

Prediction and Measurement Techniques for Radiated EMI of Power Converters with Cables

Recently, radiated electromagnetic interference (EMI) has become a research hotspot in power electronics systems, as the switching frequencies of power electronics systems have increased significantly with the adoption of wide-bandgap devices. In this article, a generalized radiated EMI model for power electronics converters with power cables is first reviewed. The radiated EMI model is then developed for a flyback power converter with critical ground impedance included. Based on the developed model, accurate high-frequency parameter extraction techniques and a radiated EMI prediction technique are developed and experimentally validated. Finally, essential measurement techniques are identified and developed to accurately extract parameters for accurate EMI prediction. The effects of the resolution bandwidth of the spectrum analyzer and critical PCB ground impedance on the radiated EMI are experimentally validated. PCB's impact on the common-mode (CM) choke's impedance and the radiated EMI is further validated. Techniques for minimizing the undesired near-field couplings in parameter extraction are discussed. The predicted EMI properly agreed with the measured EMI in the range of 30–230 MHz based on the EN55032 3 m class B standard.

Common-mode Electromagnetic Interference Mitigation for Solid-state Transformers

Solid-state transformers (SSTs) have been widely used in many areas owing to their advantages of high-frequency isolation and high power density. However, high-frequency switching causes severe electromagnetic interference (EMI) problems. Particularly, the common-mode (CM) EMI caused by the switching of the dual active bridge (DAB) converter is conducted through the parasitic capacitances in the high-frequency transformer and impacts the system reliability. With the understanding of the CM EMI model in SSTs, CM EMI mitigation methods have been studied. For passive mitigation, the coupled inductor can be integrated with the phase-shift inductor function to reduce CM EMI. For active mitigation, variations in the DAB switching frequency can help reduce the CM EMI peak. An active EMI filter can also be designed to sample and compensate for CM EMI. Using these methods, CM EMI can be reduced in SSTs.

Modeling, Analysis, and Reduction of Radiated EMI Due to the Voltage Across Input and Output Cables in an Automotive Non-Isolated Power Converter

This article investigates the radiated electromagnetic interference (EMI) due to the voltage between input and output cables in a non-isolated power converter. The radiated EMI model of a non-isolated power converter is first developed and quantified based on the circuit topologies, printed circuit board (PCB) parasitics, switching waveforms, and transfer functions. Second, an antenna model is developed for converter cables based on the antenna impedance and the antenna transfer function. Third, a complete radiated EMI model is developed based on the converter&#x0027;s EMI model and the cable&#x0027;s antenna model. Fourth, the radiated EMI is analyzed based on the developed model. Finally, two radiated EMI noise reduction techniques, optimizing PCB layout and adding a cross capacitor, are proposed. The developed radiated EMI model and the proposed radiated EMI reduction techniques are verified with both simulations and experiments. The techniques are also extended to other two non-isolated power converter topologies when the radiated EMI is caused by the voltage between the input and output cables.

Differential Mode Noise Prediction and Analysis in Single-Phase Boost PFC for the New Frequency Range of 9–150 kHz

High penetration of power electronics due to the concentration of switching frequency in the range of 9–150 kHz may create new challenging issues. Currently, regarding the recent version standard (IEC 61000-6-3), there is a lack of enough insight and fundamental studies despite reported electromagnetic interference (EMI) noise problems in this frequency range. Hence, this article proposes a time-frequency analytical modeling method for characterizing differential mode (DM) noise in a single-phase power factor correction (PFC) converter in this new frequency range. Provided comparative simulation analysis shows the proposed method's ability to estimate DM noise with a 9–150 kHz frequency range at high accuracy utilizing the double Fourier analysis method. Moreover, the obtained experimental results on a 1-kW single-phase boost PFC converter validate the proposed EMI modeling approach's effectiveness, demonstrating an error of less than 1.8 dB for the considered experimental case studies.

Black-Box Modelling of Low-Switching-Frequency Power Inverters for EMC Analyses in Renewable Power Systems

Electromagnetic interference (EMI) from renewable power systems to the grid attracts more attention especially in the low-frequency range, due to the low switching frequency of high-power inverters. It is significantly important to derive EMI models of power inverters as well as to develop strategies to suppress the related conducted emissions. In this work, black-box modelling is applied to a three-phase inverter system, by implementing an alternative procedure to identify the parameters describing the active part of the model. Besides, two limitations of black-box modelling are investigated. The first regards the need for the system to satisfy the linear and time-invariant (LTI) assumption. The influence of this assumption on prediction accuracy is analysed with reference to the zero, positive and negative sequence decomposition. It is showing that predictions for the positive/negative sequence are highly influenced by this assumption, unlike those for the zero sequence. The second limitation is related to the possible variation of the mains impedance which is not satisfactorily stabilized at a low frequency outside the operating frequency range of standard line impedance stabilization networks.

Expert System-Based EMI Modeling Method for IGBT in Electric Drive System of EV

In the working process of the electric drive system, the transient, high-amplitude, high-frequency voltage and current generated by the turn-on and turn-off of the IGBT (Insulated Gate Bipolar Transistor) are the most important sources of electromagnetic interference in EVs (electric vehicles). To this end, this paper proposes an EMI (Electromagnetic interference) modeling method for IGBT power modules of electric drive systems, which can realize accurate simulation of EMI source characteristics. First, an expert system based on IGBT model library is proposed. Then the expert system is used to simulate the characteristic curves provided in the IGBT module datasheet and extract the key parameters. Based on the expert system, an IGBT behavioral model is established, and a double-pulse simulation circuit is built to evaluate the simulation waveforms of the collector-emitter voltage, gate-emitter voltage and collector current during the two pulse switching periods. At the same time, measure the collector-emitter voltage, gate-emitter voltage and collector current test waveforms collected in the above simulation test on the built double-pulse test circuit, and compare the turn-on and turn-off processes of the simulation and test respectively to evaluate the accuracy of the EMI source model. Finally, to further test the universality of the model, the IGBT behavior model and the double pulse simulation circuit are established on the Simulink platform, and the accuracy of the model is evaluated by comparing with the test waveform. The comparative analysis results show that the proposed EMI source modeling method for IGBT power module has good versatility and accuracy.

Modeling and Reduction of Radiated EMI in a GaN IC-Based Active Clamp Flyback Adapter

This article first develops a radiated electromagnetic interference (EMI) model for a gallium nitride (GaN) integrated circuit (IC)-based active clamp flyback converter. Important capacitive couplings, which play a big role in the radiated EMI, are identified, extracted, and validated in the converter. The radiated EMI model is improved to characterize the impact of capacitive couplings. Based on the improved model, techniques to reduce capacitive couplings and the radiated EMI are proposed and experimentally validated.

EMI modeling considering the impedance behavior of isolated off-line converter

As everyone knows, the electromagnetic interference (EMI) modeling becomes more important over time. So far, many EMI models have been developed in power electronics. Almost all of them are composed of two to three impedances as well as two current or voltage sources. What distinguishes a model from another is especially its identification method, which in fact determines the most of its performances. In this paper, a new three-terminal EMI model is proposed for DC-DC converters. This model is very easy to identify, and takes into account the converter impedance behavior. The model thus proposed is a complete representation of the conducted emission behavior of the converter, where it takes not only the level of the interfering line and neutral signals, but also the complete impedance behavior of the converter. Experimental illustrations are also included to verify the validity of the proposed model. Comparison between measured and predicted results under different operating conditions with and without filter, shows that the proposed model is able to successfully predict conducted emissions up to 100 MHz with an error not exceeding 6 dB in the worst case.

A Fast and Precise Method for Modeling EMI Source in Two-Level Three-Phase Converter

Currently, frequency-domain electromagnetic interference (EMI) modeling has become the most commonly used method for EMI prediction and filter design. However, because of the unpredictability of the ringing effect in the present frequency-domain EMI modeling methods, the precision of the predicted EMI interference source is notably limited, which results in the inaccuracy of the system level EMI prediction. In order to achieve an accurate EMI prediction, this study presents a systematical study on the interference source of a 10 kVA three-phase bridge converter. The precise mathematical models of the common-mode and differential-mode interference source are constructed. Then, the characteristics of the multiple ringing effect, which is an important part of the interference source, are intensively analyzed. Based on the investigation of interference source, an improved interference source synthesis method is proposed. It can quickly and precisely predict the CM and DM interference source with multiple ringing effect, which can be used to achieve accurate frequency domain EMI prediction. Moreover, the multiple ringing effect is extended for IGBT parasitic parameter measuring. Instead of complicated device-level measurement, the grounding capacitance and junction capacitance can be effectively extracted through the ringing frequency measurement.

An Accurate and Fast Method for Conducted EMI Modeling and Simulation of MMC-Based HVdc Converter Station

The analysis of electromagnetic interference (EMI) noise of power electronic circuits involves both the transient characteristics of power semiconductor devices and the wideband stray parameters of passive equipment. Modular multilevel converters (MMCs) used in high-voltage direct current (HVdc) transmission systems contain thousands of submodules (SMs), which makes it considerably challenging to perform device-level simulation on the traditional commercial software. This article presents an accurate and fast method for wideband modeling and simulation of MMC-HVdc system for the assessment of conducted EMI during the design stage. Physical characteristics of the semiconductor devices, parasitic parameters of the insulated-gate bipolar transistor (IGBT) packages, and stray capacitances of the SMs are all taken into consideration, and massively parallel transient simulation of the wideband MMC model is carried out on the graphics processor (GPU). The accuracy and efficiency of the GPU-based parallel algorithm are validated by the comparison with the experimental measurement of an 11-level full-bridge MMC prototype. Furthermore, the stray capacitance network of the valve tower in HVdc project is extracted, and a matrix partition method based on the shielding plate configuration is utilized to conduct the computation in a fully parallelized manner. The developed GPU program is used to run the large-scale case of a 201-level two-terminal MMC-HVdc system, and the primarily affected frequency range by various factors is analyzed. Execution time test is conducted for different level topology, and it is demonstrated that the GPU can achieve a remarkable speedup over multicore CPUs, especially when the system scale is more substantial.

Development of EDA Techniques for Power Module EMI Modeling and Layout Optimization

Abstract The design of power electronics modules is undergoing renewed interest as new challenges and technologies emerge in the realm of wide bandgap (WBG) power device packaging. In order to meet the demands of these high-speed transistors, novel techniques are required to produce modules with reduced parasitics and noise generation without exceeding the operating temperature of the devices or their packaging materials. Traditionally, power module design has been a highly iterative process—repeatedly reworking and simulating designs using finite element analysis (FEA) tools that require considerable time in terms of both labor and computation. To overcome these issues, an electronic design automation tool (EDA) known as PowerSynth is ongoing in its development toward power module layout synthesis and optimization based on electrical and thermal criteria. In this paper, work to extend the capabilities of PowerSynth to optimize layouts with reduced electromagnetic interference (EMI) is presented. Optimization strategies based on the transfer functions of noise propagation paths are introduced and results showing layouts with reduced noise generation are compared with FEA simulations.

Three-Terminal Common-Mode EMI Model for EMI Generation, Propagation, and Mitigation in a Full-SiC Three-Phase UPS Module

With superior loss characteristics, wide bandgap devices such as silicon carbide (SiC) mosfet s are expected to replace Si-IGBTs in grid-connected applications. Uninterruptible power supply (UPS) is an application in which low conduction-loss and switching-loss from SiC devices can largely improve the system efficiency. However, fast switching of an SiC mosfet worsens the electromagnetic interference (EMI). In addition, the UPS is comprised of multiple converters wherein different combinations of the converters take part in power-transfer depending on the mode of operation. This complicates the prediction and strategies for noise, especially the common-mode (CM) part. Such complexity calls for deliberate strategies to be set before prototyping to contain and mitigate the CM noise. In this paper, a three-terminal CM circuit model is presented for a three-phase UPS with an active battery charger and a battery rack. The significance of a dc–dc converter on CM EMI generation and propagation has been analyzed based on the model. In a mode of operation where the dc–dc converter is active, a considerable amount of the CM noise is generated from the dc–dc converter. Also, the multiple resonances on the propagation path associated with dc inductors and the battery rack highly deteriorates CM EMI. As a mitigation strategy in the design phase, different topologies and pulsewidth modulation schemes for the ac–ac stage and the dc–dc stage have been compared based on the model. A 20-kW full-SiC UPS has been built and tested to experimentally verify the impact of the dc–dc converter operation on the noise and to validate the mitigation strategy.

Suppression of EMI radiation noise by inductor current recoil on boost PFC

As the development of switching power and power factor correction (PFC) technology in electronic devices, there is strong transient current rate and electromagnetic interference (EMI) noise caused by switching power supply MOSFET, IGBT, and other semiconductor, which can seriously affect the normal operation of electronic devices and the electromagnetic environment. This paper established a radiation EMI model of Boost PFC circuit under critical conduction mode (CRM); extracted the high-frequency noise current caused by Boost PFC switching device; proposed EMI radiation noise suppression technology by inductor current recoil; discussed the influence of the boost inductor and the parasitic capacitance, the transient current change rate, and the radiation EMI noise; built a Boost PFC hardware circuit; examined on EMI standardisation based on RE 101 (magnetic field radiation) and RE 102 (electric field radiation). It is proved that the boost inductor current recoil method can effectively suppress the radiation EMI noise of the Boost PFC circuit under CRM. Results show that the magnetic field radiation noise can be reduced to 2 dBpT in frequency 25 Hz–100 kHz, the radiation noise can be reduced to 20 dB V/m in frequency 100 kHz–5 MHz.

Estimation of Common-Mode Current Coupled to the Communication Cable in a Motor Drive System

Electromagnetic interference (EMI) couplings between a motor drive and an adjacent communication network induce a considerable common-mode (CM) current in a communication cable, which has a serious impact on the performance of the communication network. In order to estimate the CM current, it is necessary to study the coupling mechanism between the motor drive and the communication network. In this paper, a commercial motor drive system with an RS485 communication circuit is used for analysis. The conducted and near-field coupling paths are analyzed and modeled. By integrating the models of coupling paths with the EMI models of the motor drive and the dc/dc converter, an estimation model of the CM current coupled to the communication cable is built. Furthermore, online measurement methods and numerical simulation are presented to extract the impedance parameters of the conducted and near-field coupling paths. The estimation model is validated by comparing the simulated currents with the measured currents in the two configurations. This model is applicable for estimating the CM current coupled to the communication cable in various configurations.