Showing papers on "Electromagnetic compatibility published in 2021"

Adaptive Hysteresis Current Based ZVS Modulation and Voltage Gain Compensation for High-Frequency Three-Phase Converters

Abstract: This article proposed a systematic approach for the control of three-phase bidirectional zero-voltage switching (ZVS) converters. Combining the adaptive hysteresis-band current control and turn- on delay modifications, ZVS conditions are realized in full line-cycle in all loading conditions like active power, reactive power, light load, and heavy load. The soft-switching resonant period is carefully analyzed, and the current band is designed accordingly, which minimized the additional conduction loss. Meanwhile, a zero-sequence voltage injection control is included in the approach, which compensates the voltage gain by 15% and narrows down the switching frequency variation range. The hardware design approach is also provided including the LCL filter design and a low-cost high-bandwidth high-accuracy current sensor design. A highly integrated 5-kW silicon carbide implemented three-phase ZVS converter prototype with printed circuit board integrated inductors and customized current sensors is designed. All the control is implemented in a single microcontroller unit, which achieves a high electromagnetic compatibility. The designed prototype achieves a total power density of 5.5 kW/L and a peak efficiency of 98.5%. All the analysis and the proposed control approach are experimentally verified on the designed prototype.

Modelling, fabrication and characterization of graphene/polymer nanocomposites for electromagnetic interference shielding applications

Abstract: The mitigation of electromagnetic pollution is becoming an increasing issue due to the proliferation and miniaturization of electronic components. Electromagnetic interference (EMI) shields must be considered to bring about electromagnetic compatibility (EMC), where analyzing the shielding effectiveness (SE) is of great importance. Graphene-enhanced polymer composite materials are recently introduced as a replacement for metal-based EMI shielding materials due to their low cost, resistance to corrosion, lightweight, versatile, and straightforward processability, as well as broad bandwidth properties compared to conventional metal-based materials. The SE can be determined from the bulk material properties, including permittivity, permeability, and conductivity, using analytical or numerical solutions to Maxwell's equations. Though, Due to the heterogeneity of graphene-based polymer composites, characterization of these values remains difficult. This article attempts to summarise and critically review the state-of-the-art progress in the fabrication and characterization of these materials. Also, this review elaborates on accurate modelling techniques based on the underlying micromechanics, e.g., percolation, electron tunnelling, agglomeration, imperfect interface, frequency-dependent nanocapacitance and electron hopping. The model is designed to predict the electromagnetic properties of the nanocomposite from the pre-determined properties of the polymer matrix and carbon-based filler. This understanding may ultimately lead to the development of graphene/polymer composites with optimized EMI shielding properties to develop emerging EMI shielding materials. This paper focuses heavily on Graphite Nanoplatelet (GnP)/Epoxy as the choice of graphene/polymer.

Power Quality Phenomena, Standards, and Proposed Metrics for DC Grids

Abstract: This work addresses the problem of power quality (PQ) metrics (or indexes) suitable for DC grids, encompassing low and medium voltage applications, including electric transports, all-electric ships and aircrafts, electric vehicles, distributed generation and microgrids, modern data centers, etc. The two main pillars on which such PQ indexes are discussed and built are: (i) the physical justification, so the electric phenomena affecting DC grids and components (PV panels, fuel cells, capacitors, batteries, etc.), causing, e.g., stress of materials, aging, distortion, grid instability; and (ii) the existing standardization framework, pointing out desirable coverage and extension, similarity with AC grids standards, but also inconsistencies. For the first point, each phenomenon is discussed with quantitative conclusions on relevant thresholds: in many cases some percentage of distortion (ripple) is acceptable (stress on capacitors and storage, impact on fuel cells, and PV panels), whereas in other cases, much higher levels may be tolerated (interference to protection and monitoring devices). Standards are reviewed for indications not only of low-order harmonics and voltage fluctuations typical of old DC grid schemes, but also for high-frequency noise, including thus supraharmonics and common-mode disturbance, and filling the gap with the electromagnetic compatibility domain. However, phenomena typical of EMC and electrical safety (such as various types of overvoltages and fast transients) are excluded. Suitable PQ indexes are then reviewed, suggesting integrations and modifications, to cover the relevant phenomena and technological progress, and to better follow the normative exigencies: ripple is considered in time and frequency domain, in particular with a band limited implementation; for transients and pulsed loads, more traditional indexes based on area, energy, and half duration are confronted with indexes evaluating the power trajectory and its derivative.

Input/output EMI filter design for three-phase ultra-high speed motor drive gan inverter stage

Abstract: Pairing wide-bandgap (WBG) inverters with highspeed motors results in compact and efficient motor drives, but requires special attention on electromagnetic interference (EMI) aspects. This paper focuses on electromagnetic compatibility (EMC) of high-speed motor drives, supplied by a DC source. In order to protect the nearby equipment from the EMI noise of the WBG inverter, a filter that complies with conducted EMI regulations is placed at the inverter DC input-side. However, there is no clear mandate requiring from inverters to comply with conducted EMI regulations at the AC output-side, where only the motor is placed. For this reason, there is no full consensus whether it is necessary to use an output filter, and if so, what type of output filter would be suitable, i.e., if differential-mode (DM), common-mode (CM) or both DM/CM output filter would fit best. A full sine-wave output filter (FSF) is proposed in this paper, that features both DM and CM attenuation, and capacitors connected to the DC link. Besides the several well established benefits of a FSF, such as purely sinusoidal motor currents and the protection of the motor against high dw/dt originating from the fast switching of the semiconductor devices, a FSF at the inverter output-side, also reduces the CM EMI emissions at the inverter input-side. Namely, since the inverter housing, the motor housing and the interconnecting shielded cable are all grounded, CM emissions generated at the inverter output-side are directly mapped to the inverter input-side, i.e., there is an input-to-output CM noise interrelation. A FSF reduces the output-side CM EMI emissions and thus mitigates the input-to-output CM noise mutual influence. Two types of FSF (c-FSF and d-FSF) are comparatively evaluated, in terms of volume, losses and EMI performance. The theoretical consideration are tested within the context of a high-speed 280 krpm, 1 kW motor drive, with 80 V DC supply. The experimental results validate the good performance of the proposed filter concept.

The Effect of EMI Generated from Spread-Spectrum-Modulated SiC-Based Buck Converter on the G3-PLC Channel

Abstract: Power line communication (PLC) is increasingly emerging as an important communication technology for the smart-grid environment. As PLC systems use the existing infrastructure, they are always exposed to conducted electromagnetic interference (EMI) from switching mode power converters, which need to be tightly controlled to meet EMC regulations and to ensure the proper operation of the PLC system. For this purpose, spread-spectrum modulation (SSM) techniques are widely adopted to decrease the amplitude of the generated EMI from the power converters so as to comply with EMC regulations. In this paper, the influence of a spread-spectrum-modulated SiC-based buck converter on the G3-PLC channel performance is described in terms of channel capacity reduction using the Shannon–Hartley equation. The experimental setup was implemented to emulate a specific coupling path between the power and communication circuits and the channel capacity reduction was evaluated by the Shannon–Hartley equation in several operating scenarios and compared with the measured frame error rate. Based on the obtained results, SSM provides the EMI spectral peak amplitude reduction required to pass the electromagnetic compatibility (EMC) tests, but results in increased EMI-induced channel capacity degradation and increased transmission error rate in PLC systems.

Impact of rail impedance intrinsic variability on railway system operation, EMC and safety

Abstract: Running rails in electrified transportation systems are the interface element for several phenomena related to system performance, electromagnetic compatibility and safety: useful voltage at rolling stock, short circuit current, induced voltage, stray current, and track circuit operation. This work presents the physical and mathematical groundings of rail electrical parameters (dc and ac resistance, ac internal and external inductance) and experimental results available in the literature, discussing variability and reliability for each interface. The results consist thus of the identification of the relevant rails longitudinal electrical parameters, the presentation of a set of reliable experimental values, and the discussion of the best approach to manage their variability and uncertainty.

Providing Electromagnetic Compatibility of High-Power Frequency Converters with Active Rectifiers at Internal Power Supply System of Cherepovets Steel Mill

Abstract: This paper presents the method of ensuring electromagnetic compatibility of frequency converters with active rectifiers ACS6000 as a part of main electric drives of four-stand mill with 10 kV distribution network of in-plant power supply system at JSC “Severstal” Cherepovets Steel Mill. The essence of the used method was in application of improved algorithms of PWM for active rectifiers of frequency converters ACS6000 ensuring harmonic composition alteration of currents consumed by ARs with exclusion of harmonics falling into the zone of resonances in the frequency response of the network relative to sections of 10 kV GPP-2. Theoretical studies were conducted on a complex mathematical model of the main electric drives of the mill and the internal 10 kV distribution network implemented in the mathematical package Matlab-Simulink. The analysis of research results showed the effectiveness of the proposed method in terms of reducing the total harmonic distortion factor on the sections of the main step-down substation of the plant, which are intrafactory points of common connection.

Conducted Emission Suppression Using an EMI Filter for Grid-Tied Three-Phase/Level T-Type Solar Inverter

Abstract: Electromagnetic interference in power converters is a crucial problem for circuit designers. Electromagnetically compliant converter design is required for the safety of an operation. A novel filter design approach considering ground leakage current, different winding styles for common mode choke, tolerance of filter capacitor is proposed in this study to solve the electromagnetic interference problem. In the study, electromagnetic compatibility issue is investigated for a 25 kW, 15 kHz switching frequency, three-phase/level T-type grid-connected solar inverter. The test setup is installed based on EN55011 standard, and the interferences emitted by the inverter to the grid through conduction are measured. Then, a filter design is made to prevent these interferences from being transmitted to the grid. After the filter is designed and engaged, the measurements are repeated. So, the noise attenuation of the EMI filter is verified experimentally. Experiences obtained from the hardware modification in the EMI filter, which is designed for an industrial solar inverter, have been discussed. It is observed that the result of conducted emission measurement is within the limits of the EN55011 Class B standard.

Analysis of the Angle Modulated Switching Strategy for use With Fractional Horse Power BLDC Motors

Abstract: In recent years, electromagnetic compatibility (EMC) has become progressively important because of the rise in the number of electronic auxiliary devices in motor vehicles. This article presents an angle modulated switching strategy for fractional horsepower drives. It allows decreasing the size of the necessary EMC filter, for the example case drive used, down to less than 50%, from nine to four capacitors. Simultaneously, it reduces the radiated electromagnetic emissions over a wide frequency range by almost 10 $\,\text{dB}_{\mu \text{V/m}}$ . The EMC measurements performed in a shielded chamber are compared with the results for two conventional switching strategies. Subsequently, the influence of the presented switching strategy on the efficiency and on the emitted airborne and structure-borne noise is investigated.

Measuring and Separating Conducted Three-Wire Emissions From a Fault-Tolerant, NPC Propulsion Inverter With a Split-Battery Using Hardware Separators Based on HF Transformers

Abstract: Conducted emissions on the traction battery's power cables in EVs must be limited to avoid unwanted electromagnetic interference (EMI). When designing an EMI filter, it is advantageous to have information of the common mode (CM) and differential mode (DM) noise levels. This article deals with the measurement and separation of the dc side's three-wire DM/CM noise of a fault-tolerant three-level neutral-point-clamped (NPC) inverter with a split-battery system. Two hardware separators, based on small-circuit highfrequency transformers, were developed to identify the dc side's CM, line-DM, and phase-DM noise levels. Their characterized CM and DM rejection ratios for the frequency range from 150 kHz to 110 MHz are at least $-$ 33 and $-$ 21 dB, respectively. The separated noise of the NPC inverter was measured, using an inductive load, when operating the inverter with three-level and two-level modulation, resembling normal operation and a possible operation under fault, respectively. A simple three-wire CM model of the used testbed and the DM power module oscillation were derived to validate the separated noise's resonance peaks/valleys. It has been seen that the CM noise is dominant, especially below 10 MHz, except for the power module oscillations. Furthermore, when using the two-level modulation, in the case of a clamping diode fault, the noise levels are increased by about 3 dB.

Radiated EMI Reduction with Double Shielding Techniques in Active-clamp Flyback Converters

Abstract: Electromagnetic interference (EMI) issue becomes a headache problem when the switching frequency has been pushed higher and higher for the smaller size and higher power density. Up to now, the conducted EMI can be controlled very well with decades of exploration and research. However, the radiated EMI is still hard to be understood and controlled, the techniques to reduce the radiated EMI are limited. In this paper, active-clamp flyback converters are taken as the example, the radiation model is developed, the double shielding technique is proposed to mitigate the radiated EMI effectively no matter the EMI filters are placed on the AC line or DC bus. The concept of this technique is explained in detail, the experiments are conducted to verify the analysis. The guideline to choose the appropriate connection method of the double shielding technique is given for both the AC line and DC bus EMI filters.

Critical Review of EMC Standards for the Measurement of Radiated Electromagnetic Emissions from Transit Line and Rolling Stock

Abstract: Accurate and comprehensive methods for the assessment of radiated electromagnetic emissions in modern electric transportation systems are a necessity The characteristics and susceptibility of modern victim signaling and communication radio services, operating within and outside the right-of-way, require an update of the measurement methods integrating or replacing the swept frequency technique with time domain approaches Applicable standards are the EN 50121 (equivalent to the IEC 62236) and Urban Mass Transport Association (UMTA) with additional specifications from project contracts This work discusses the standardized methods and settings, and the representative operating conditions, highlighting areas where improvements are possible and opportune (statistical characterization of measurement results, identification and distinction of emissions and line resonances, and narrowband and broadband phenomena) In particular for the Electromagnetic Compatibility (EMC) assessment with new Digital Communication Systems, the characterization of time distribution of spectral properties is discussed, eg, by means of Amplitude Probability Distribution and including time distribution information The problem of determination of site and setup uncertainty and repeatability is also discussed, observing on one hand the lack of clear indications in standards and, on the other hand, the non-ideality and intrinsic variability of measurement conditions (eg, rolling stock operating conditions, synchronization issues, and electric arc intermittence)

Intelligent Electromagnetic Compatibility Diagnosis and Management With Collective Knowledge Graphs and Machine Learning

Abstract: The explosive growth of electronic devices brings a soaring demand for rapid electromagnetic compatibility (EMC) diagnosis. However, there is a significant learning curve for the electrical engineers to apply EMC knowledge. In this article, an efficient EMC diagnosis and management methodology was proposed, which provided a fast way for EMC analysis in seconds other than traditional simulation or calculation. The approach organized the EMC knowledges as knowledge graph composed by the interference/sensitive units, and mathematical set rules. The optimized graph structure is in form of rule, maxterm, basic unit, and entity layers. Based on the condensed relationships, it achieved high searching efficiency and graph expansibility. To facilitate the information retrieval from the knowledge graph, the interference/sensitive units and related parameters were acquired from interactive sessions, in which long short-term memory method was used to extract entities. The EMC specialized corpora were fed in training to enhance the accuracy of inference. Finally, the EMC diagnosis and management reports were automatically generated by knowledge graph searching application. The proposed method improved the calculation efficiency by three times. The storage of relationships and attributes of nodes was reduced by 76% and 60.7%. The identification accuracy was enhanced from 77.7% to 99.5%. The presented method is practically useful for EMC design in crosstalk analysis, radiated, and conducted interference diagnoses.

Analysis of Permanent Magnet Motors in High Frequency—A Review

Abstract: Electric drives consume a great amount of the world’s energy, and it will keep increasing due to the electromobility trend. Thus, the efficiency of electric drives must be improved to reach the desired sustainability goal. The Silicon Carbide devices contribute to this objective due to their high working frequency and lower switching losses. However, working at higher frequencies may bring serious Electromagnetic Compatibility (EMC) problems, as well as insulation stress and higher bearing currents. Hence, it is important to have an electrical machine electrical equivalent circuit model to predict the electromagnetic interference levels. This review summarizes the current state of the art in electrical machine modeling and analysis in high frequency. The main analysis tools as Finite Element Methods, analytic and measurement-based tools are compared in their application on high-frequency electrical machine analysis. Then, different machine high-frequency models are reported, detailing their individual features. Additionally, the influence of the machine design parameters in EMC behavior is outlined for future analysis. All in all, Finite Element analysis is the most accurate tool for high-frequency analysis, provided that mesh size is thinner than the skin depth. It is also concluded that the winding placement is an essential parameter to define the high-frequency behavior of the machine.

A Deep Learning Method for Modeling the Magnetic Signature of Spacecraft Equipment Using Multiple Magnetic Dipoles

Abstract: In this letter, a deep-learning-based neural network for magnetic dipole modeling (MDMnet) is introduced in the framework of dc magnetic cleanliness for space missions. The developed method targets modeling the static magnetic signature of a spacecraft unit that is obtained during the unit-level characterization stage of the extensive prelaunch electromagnetic compatibility test campaign. By employing synthetic magnetic flux density data generated by virtual dipole sources, the MDMnet can be trained to accurately estimate the magnetic parameters of real equipment based on its near magnetic flux density measurements. The target of the deep learning algorithm is, on the one hand, to effectively minimize the prediction errors (loss function) throughout the training process and, on the other hand, to enable the generalization of the model predictions, i.e., exhibit accurate model estimations with unseen magnetic induction data. Extensive simulations toward the stabilization of the MDMnet hyperparameters are outlined, and indicative model inferences employing artificial magnetic flux density data are carried out. Finally, the MDMnet can achieve a predictive accuracy of 0.8 mm with respect to the dipole localization and 1% with respect to the magnetic induction magnitude, verifying the potency of the developed method.

Near-Field Precision Measurement System of High-Density Integrated Module

Abstract: An automatic near-field precision measurement system was proposed in this article. The work was mainly focused on the hardware structure design of the near-field precision measurement system and the software development of the upper computer. At the same time, the electromagnetic field probes used in the system were selected and introduced. The near-field precision measurement system was composed of an upper computer control part, motion controller, power amplifier module, three-axes mechanical arms, spectrum analyzer, and near-field probes. Three-axes mechanical arm, multi-degree-of-freedom fixture, and electromagnetic field probe cooperate with each other for near-field measurement. The electromagnetic radiation emission of high-density integrated module and liquid crystal display (LCD)-printed circuit board (PCB) of laptop computer were measured. According to the measured data, the visual field distribution map was generated, and the measured results were analyzed. Compared with manual measurement method and commercial electromagnetic compatibility (EMC) scanners, the near-field precision measurement system has more accurate measurement results and can accurately locate the noise source.

Review of Contactless Energy Transfer Concept Applied to Inductive Power Transfer Systems in Electric Vehicles

Abstract: Nowadays the groundbreaking tools of contactless energy transfer reveals new opportunities to supply portable devices with electrical energy by eliminating cables and connectors. One of the important applications of such technology is the energy providing to electric and hybrid vehicles, (EV) and (HEV). These contribute to the use of cleaner energy to protect our environment. In the present paper, after exposing the contactless energy transfer (CET) available systems, we examine the appropriateness of these systems for EV. After such exploration, it is shown that the most suitable solution is the inductive power transfer (IPT) issue. We analyze such procedure in general and indicate its main usages. Next, we consider the practice of IPT in EV and the different option in the energy managing in EV and HEV concerning battery charging. Following, we review the modes of using the IPT in immobile case and in on-road running. Following, the modeling issues for the IPT system escorting the vehicle structure are then exposed. Lastly, the electromagnetic compatibility (EMC) and human exposure analyses are assessed involving typical appliance.

SI/PI-Database of PCB-Based Interconnects for Machine Learning Applications

Abstract: A database is presented that allows the investigation of machine learning (ML) tools and techniques in the signal integrity (SI), power integrity (PI), and electromagnetic compatibility (EMC) domains. The database contains different types of printed circuit board (PCB)-based interconnects and corresponding frequency domain data from a physics-based (PB) tool and represent multiple electromagnetic (EM) aspects to SI and PI optimization. The interconnects have been used in the past by the authors to investigate ML techniques in SI and PI. However, many more tools and techniques can be developed and applied to these structures. The setup of the database, its data sets, and examples on how to apply ML techniques to the data will be discussed in detail. Overall 78961 variations of interconnects are presented. By making this database available we invite other researchers to apply and customize their ML techniques using our results. This provides the possibility to accelerate ML research in EMC engineering without the need to generate expensive data.

Adaptive Space-Time and Polarisation-Time Signal Processing in Mobile Communication Systems of Next Generations

Abstract: The possibilities of improving electromagnetic compatibility in mobile communication systems of next generations are analysed based on application of adaptive space-time signal processing in antennas of base stations Features of solving the problem of interference suppression in adaptive antenna arrays are considered using recurrent adaptation algorithms realized on the basis of the minimum mean square error criterion The results of modelling adaptation of signal processing and its analysis are presented A promising method of interference suppression using polarisation-time processing of signals using optimal stochastic control is considered

Simulink-Based FPGA Control for EMI Investigations of Power Electronic Systems

Abstract: Control schemes applying sinusoidal pulsewidth (sPWM) have been widely employed in power conversion solutions. With the development of the future smart grid, more capabilities of the converters are required introducing additional electromagnetic interference (EMI) control measures. In this article, a MATLAB controllable sPWM generator has been developed to optimize electromagnetic compatibility. The field-programmable gate array running at 100 MHz is capable of producing simultaneous and synchronous control signals for 16 power electronic switches. Six flexible control parameters have been implemented, which allow the controller to be tuned to a large number of applications and investigate several EMI mitigation techniques and investigate the disturbance dependence on operational parameters. As an example, the detrimental dead time effect is shown, with a variation in emissions of 10–20 dB in the frequency range of 50 kHz to 50 MHz. Highest experimentally tested switching frequencies have been recorded at 2 MHz with resulting sinusoidal waveforms from 50 Hz to 250 kHz.

Analysis and Research on Electromagnetic Compatibility of High Speed Railway Traction Current Harmonics to Track Circuit

Abstract: The harmonic interference during the operation of rolling stock or EMU is an important interference source of signal system, especially the running track circuit. The harmonic currents in the signal band exceed the limit, which will affect the reliable operation of the track circuit. Analysis of harmonic characteristics based on traction current and the principle of harmonic suppression, a method of harmonic suppression using multiple control strategies is proposed according to the harmonic distribution characteristics of track circuit. Effectiveness of multiple control strategy for harmonic suppression of traction current is verified by simulation analysis and line operation test. The RMS of traction harmonic current can be controlled in the range of 0.3A. The overall performance of the vehicle is optimized and the electromagnetic interference of the track circuit is effectively suppressed.

In-Circuit Differential-Mode Impedance Extraction at the AC Input of a Motor Drive System

Abstract: The in-circuit differential-mode (DM) impedance at the AC input of a motor drive system (MDS) serves as a key parameter to evaluate and estimate the DM electromagnetic interference (EMI) noise caused by the switching of power semiconductor devices in the MDS. This paper discusses a single-probe setup (SPS) with frequency-domain measurement to extract the in-circuit DM impedance of an MDS under its different operating modes. The advantages of the SPS are its non-contact measurement and simple structure.

Measurement of In-Circuit Common-Mode Impedance at the AC Input of a Motor Drive System

Abstract: The in-circuit common-mode (CM) impedance at the AC input of a motor drive system (MDS) provides valuable inputs for evaluating and estimating the CM electromagnetic interference (EMI) noise generated by the switching of power semiconductor devices in the MDS. This paper introduces a single-probe setup (SPS) with frequency-domain measurement to extract the in-circuit CM impedance of a MDS under its different operating modes. The SPS has the merits of noncontact measurement and simple structure.

Mains-Synchronized Pulse Density Modulation Strategy Applied to a ZVS Resonant Matrix Inverter

Abstract: Multi-output inverters have become a key enabling technology to increase surface flexibility in domestic induction heating appliances. The most commonly used power converter topologies are based on electromechanical relays in order to multiplex the connected loads and obtain a proper heat distribution. This solution, which is used in combination with other modulations such as square waveform, relies on the thermal inertia of the pot as it needs long power-averaging periods to reduce the reiteration of the switching noise. However, it presents a significant limitation in terms of acoustic noise, reliability, and thermal performance. To overcome these limitations, complete solid-state inverters that can be operated at higher frequencies are proposed. This change in the design paradigm of the pulse density modulation strategies leads to improved thermal control in the pot and better user experience, but at the same time increases challenges due to design constraints imposed by electromagnetic compatibility regulations. This article analyzes the possibilities of a new mains-synchronized pulse density modulation applied to a flexible induction cooktop that uses a multiple-output ZVS resonant inverter topology. The feasibility of the control strategies has been tested by means of a prototype featuring 12 2-kW induction heating loads.

Stator Impedance Modeling Platform for the Electromagnetic Compatibility Aware Design of 3.7- to 7.5-KW Squirrel-Cage Induction Motors

Abstract: This article presents an electromagnetic compatibility (EMC) aware motor design method based on the prediction of the impedances of a stator winding structure. The stator structure is divided into several two-dimensional parts, and their network parameters are extracted by electromagnetic (EM) simulations. Through conversion and synthesis of the multiport network parameters, the input impedance can be found for the full-winding structure. The calculated input impedance approximately follows the measured impedance of tested induction motors. The impedance calculation method has been realized in a parametric analysis platform to enable the EMC-aware design of induction motors. By using the platform, the variations of the input impedances by different design parameters can be analyzed along with consideration of loss and torque ripple. To verify the proposed method, prototype motors were assembled and the common-mode (CM) currents were measured under driving operation. The results show that the CM current can be reduced up to 10 dB in the frequency range of interest when the number of parallel circuit is reduced, as estimated from the calculated input impedances.

Cancellation Conditions of Magnetic Field Leakage From Inductive Power Transfer Systems

Abstract: In inductive power transfer systems, a transmitter array can maintain high power transfer efficiency (PTE), despite lateral misalignment between the transmitter and receiver. However, a control method for reducing magnetic field leakage in this situation has not been found. Therefore, a novel theory of controlling the transmitter array is necessary for electromagnetic compatibility and user safety. In this study, we optimize the input currents at the transmitter array and the load impedance at the receiver to maximize PTE under the cancellation condition of the magnetic field leakage. Simulations show that the proposed method reduces magnetic field leakage by more than 10 and 38 dB, with and without ferrite plates, respectively, compared with existing PTE maximization methods, even when there is a lateral misalignment between the transmitter and receiver. Additionally, experiments using coils having ferrite plates show that the proposed method reduces magnetic field leakage by more than 6.75 dB. The decrease in PTE is within 4.17 %, which compares favorably with existing methods.

Common Mode and Differential Mode noise of AC/DC LED Driver

Abstract: Electromagnetic interference (EMI) represents one of the biggest problems facing the production of any electronic device. The impact on the performance of the device caused such unwanted interference must be carefully measured to understand and quantify the electromagnetic compatibility (EMC) of the instrument under test. The electrical power conversions are among the sources of electromagnetic pollution, they provide a low power factor and generate electromagnetic interference (EMI). The white light emitting diode (LED) has attracted a lot of attention from industry and scientific researchers due to its high efficiency, easy of driving, and long life. Nevertheless, LED driver can interfere with the electronic device system due to rapid voltage variation and current. In this paper we simulate some LED driver topology on LTspice software in order to measure the electromagnetic disturbances using LISN (line impedance stabilizer network) device.

Electromagnetic Compatibility of Power Electronic Devices in Electric Vehicle Drive System

Abstract: Most of the electromagnetic interference of electric vehicles comes from the electric drive system. In this paper, the electromagnetic interference (EMI) of power components in electric vehicle (EV) drive system is studied, including its propagation path and the method of interference measurement. On this basis, the common methods to reduce electromagnetic interference are explored, and the future development of electromagnetic compatibility of electric vehicles is prospected.