Considerations on Electromagnetic Compatibility for Medical Devices

Motors in Adjustable Speed Drive (ASD) systems are the major sources of conducted Electromagnetic Interference (EMI), and they are mainly the Common-Mode (CM) currents and voltages. Compliance with Electromagnetic Compatibility (EMC) standards is of utmost importance when maintaining system reliability in the face of ever-stricter Electromagnetic Compatibility standards in the industrial sectors. This work presents the first systematic experimental evaluation of CM impedance in Split Phase Induction Motors (SPIMs) in a wide frequency range (100 Hz to 100 MHz). Unlike prior studies that were limited to either a differential-mode analysis or limited frequencies in the experiment, the study provides comprehensive CM impedance data of two different SPIM setups, explaining resonance and anti-resonance behaviors that have direct implications on EMC performance. It is experimentally proven that high impedance designed motors significantly reduce CM current transfer, thus reducing EMI emissions and enhance EMC compliance. Particularly, the impedance peak of SPIM (I) was 8k at 100 MHz that translated to a 45% decrease in CM current and −15 dB attenuation of conducted EMI compared to SPIM (II). The resonance and anti-resonance frequencies determined the influence of motor architecture on its susceptibility to EMI. As a result, the findings provide prescriptive design information to the optimization of SPIMs in applications, for example, industrial automation and electric vehicle platforms, where very high EMI mitigation levels are of crucial importance.

This paper deals with energy/power quality issues, correlated with Electromagnetic Compatibility (EMC) and electromagnetic interferences (EMI) which appear at urban transportation systems. One presents, briefly, some aspects regarding powers definitions for harmonic and/or unsymmetrical regimes from three-phase circuits, applicable to loads supplied from the a.c. line through low voltage power transformers and uncontrolled three-phase rectifiers. It is analysed the case of a driving system with d.c. motor and chopper, supplied from the d.c. line, which induces a significant non-sinusoidal regime in the a.c. network. The cases in which the load is not compensated, respectively compensated through an active filter are also analyzed through tests on stand. Aspects regarding powers and power flows for both cases are also discussed. Furthermore, the obtained data are compared using the quality standards IEEE 519/1992 and 1459/2000. One discusses the obeying of quality standards and some aspects, which are not approached in the specialty literature, concerning the corresponding EMC and EMI issues. Problems related to the tested driving system connection to the supplying system from the power substation for an urban transportation system are briefly presented. The waveforms of currents through the active filter are depicted. Some conclusions on approaching EMC and EMI at low frequencies, with an extension over 2 kHz and the relation with the IEC 61000-4-30 standard are also presented. It is underlined the necessity of treating energy/power quality issues in correlation with issues regarding EMC and EMI at low frequency for this type of loads.

Switching power converters cause electromagnetic interference (EMI), which can disturb the normal operation of the converter itself and other adjacent systems. Power converters must comply with electromagnetic compatibility (EMC) standards to guarantee proper operation of converters and nearby systems. Soft switching methods can be employed as EMI mitigation techniques in power converters. Although, soft switching converters are commonly addressed to have lower EMI than hard switching counterparts, they may not satisfy EMC regulations. In this study, spread spectrum by the means of pseudorandom modulation is applied to a zero-current transition (ZCT) flyback converter. By extracting the converter EMI model, the effect of using ZCT soft switching method is simulated and compared to its hard switching counterpart. The reduced amount of conducted electromagnetic emission is demonstrated via the proposed simulation method. To justify the theoretical analysis, the experimental results are presented.

As the trend of consumer electronics and mobile communications devices is obviously developing toward to miniature and high-speed processing, the problem involving with electromagnetic compatibility (EMC) or radio frequency interference (RFI) is becoming more critical for the system integration of high-speed digital and RF mixed signal platforms. This paper is mainly focusing on the characteristics analysis of various electromagnetic shielding materials by utilizing the various shielding effectiveness (SE) measuring methods developed by TDK and ASTM (ASTM D4935). We also adopt the electromagnetic interference (EMI) testing methods developed by IEC for chip level (IEC 61967-3 and IEC 61967-6) to investigate the characteristics and distribution of EMI noise sources. To effectively shield the electric, magnetic, or electromagnetic field originated from noise source, we thus analyze the shielding capability for various materials with different measuring methods. Finally, we will show the EMI reduction and RF performance improvement with implementation of shielding material on module under investigated. With the systematic measurement and analysis described in this paper, we can further identify the related EMI problem and resolve the severe chip or module level EMC problem more effectively.

Electromagnetic compatibility (EMC) is a critical aspect of electronic and electrical systems, ensuring their ability to function properly within a shared electromagnetic environment without causing or suffering from unacceptable interference. This study employs the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), a multi-criteria decision-making method, to evaluate and rank various EMC parameters. The analysis considers several key EMC factors, including the EMC directive, radiated emissions, conducted emissions, electromagnetic interference (EMI), EMC standards, and electromagnetic susceptibility (EMS). The EMC directive, which serves as a guiding framework for managing electromagnetic disturbances in devices, emerged as the top-ranked criterion, underscoring its pivotal role in regulatory adherence and standardization. Radiated emissions and conducted emissions secured the second and third ranks, respectively, highlighting their substantial impact on EMC performance. Effective management of these emissions is crucial for mitigating potential interference with communication systems, aircraft equipment, and other electronic devices, thereby enhancing the reliability and coexistence of products within the electromagnetic spectrum. Electromagnetic interference (EMI) and EMC standards followed closely, ranking fourth and fifth. EMI shielding and compliance with EMC standards are vital for preventing disruptions caused by electromagnetic radiation and ensuring the smooth operation of electronic circuits and wireless networks. Adherence to these standards promotes interoperability and minimizes the risk of performance degradation. Lastly, electromagnetic susceptibility (EMS) ranked sixth, emphasizing the importance of assessing the sensitivity of electronic devices to electromagnetic energy. By understanding and mitigating EMS, manufacturers can enhance the immunity of their products to external interference, reducing the likelihood of operational issues or physical damage. The TOPSIS method facilitated a comprehensive analysis by considering the ideal and negative ideal solutions, ultimately ranking alternatives based on their proximity to the optimal scenario. The results underscore the multifaceted nature of EMC and the need for a holistic approach that considers various aspects, from regulatory directives to emission control and interference mitigation. By leveraging the TOPSIS method, decision-makers can prioritize and allocate resources effectively, ensuring that EMC challenges are addressed comprehensively and proactively, thereby promoting the harmonious coexistence of electronic systems within the electromagnetic environment.

Unmanned Aircraft Systems may allow to y an uninhabited airplane or satellite with an autonomous control and monitored by the supervisor on ground. Safety y must be guarantee as the rest of airworthiness airplanes or space compliance satellites. The Unmanned Aircraft Systems were designed to operate in dangerous situations, like military missions bud nowadays, civil commercial applications come to be feasible due to the evolution in distributed embedded avionics systems. Dull and tedious surveillance applications are desired for this Unmanned Aerial Vehicles. A pico-satellite is a less than a kilogram mass satellite used mainly on educational projects for Low Earth Orbit (LEO) missions. Due to short time of live, down-link communications are implemented in a very high level of integration and non-gravity conditions in order to deliberate the scienti c information before drop down to the atmosphere. Both, Unmanned Aerial Vehicles and pico-satellites present same electromagnetic compatibility problems. This high level of integration, some times brings an electromagnetic interference situation between embedded systems especially because the near eld of emissions are present in the Unmanned Aircraft System reduced con ned avionics bay. Emission, Susceptibility, and Path are playing in this environment. That was our experience with an UAV Megastar model. The near earth antenna re ection produced a multi-path coupling. The radio transmitter antenna makes unserviceable the entire ight control surfaces, situation that makes an unsafe y. Also, during the pico-satellite design we must take in consideration the near eld for a good electromagnetic compatibility requirements. This paper is an electromagnetic compatibility study for Unmanned Aircraft System. We will show a case of real electromagnetic interference in our particular UAV Megastar, and how was solved. We will present some good EMC practices in order to translate the distributed embedded avionics platform to our new UAV Shadow MK1. Also we present our pico-satellite design and many examples of solutions of electromagnetic interferences. Finally we will consider an electromagnetic interference reduction check list applied on Unmanned Aircraft System where avionics bay con guration may change depending on the requirements of the mission.

Electrostatic discharge (ESD) has been known to cause electromagnetic noise against electronic equipment and devices even before the technical concept of electromagnetic compatibility (EMC) was established 68 years ago in the United States and 48 years ago in Japan, while the ESD still continues to be studied as one of the most significant issues that should be solved in EMC areas. This is largely because the underlying nature of ESD has yet to be essentially elucidated from an EMC perspective. On the other hand, as an academic research organization on EMC in Japan, a Technical Committee named ‘EMCJ’ on ‘Environmental Electromagnetic Engineering’ was founded in 1976 in both the Institute of Electrical Engineers of Japan (IEEJ) and the Institute of Electronics and Communication Engineers or the present IEICE (Institute of Electronics, Information and Communication Engineers) to address EMC concerns. Since then, the EMCJ has been jointly conducting EMC research activities under the IEICE as the nominating body and the IEEJ as the associative body, whereas the EMCJ of IEEJ was dissolved in 1999 to form a new Technical Committee on EMC (TC‐EMC) in order to deal with EMC issues appropriate to the IEEJ. In this review, to mark the 25th anniversary of the IEEJ Technical Committee on EMC (TC‐EMC) in 2024, the EMC research efforts and activities that the TC‐EMC has conducted over the past 25 years from January 2000 to March 2024 are surveyed from 1272 technical papers presented at the technical meetings. Furthermore, among the ESD issues identified in these technical papers, the latest case studies utilizing ‘spark resistance laws’ that allow the analysis of the initial behavior of sparks, in which a spark is the essence of ESD and is the key to open the door to elucidate the phenomenon, particularly from an EMC perspective, are reviewed. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

In the process of high-efficiency control of aircraft, power electronic equipment brings a series of electromagnetic interference problems due to its own electromagnetic characteristics, which makes the electromagnetic environment on the aircraft carrier become worse. Therefore, it must take measures to control the electromagnetic interference. In this paper, the mechanism of electromagnetic interference generation of airborne power electronic equipment is analyzed. And some electromagnetic interference control techniques are proposed from the aspects of anti-interference design and electromagnetic compatibility test which can provide technical guidance for electromagnetic compatibility design and testing of airborne power electronic equipment.

There is serious conducted electromagnetic interference (EMI) in the application of medium-power variable-frequency drive (VFD) systems. The EMI passive filters which can suppress the noise can make the VFD systems comply with the relevant electromagnetic compatibility (EMC) standards. In this paper, combined with the experiment and measuring experience in related subjects, it describes the proper use of the filter, and does the EMI noise test. At the same time, a series of corrective measures and precautions are summed up. The final results testified the filter and the corrective measures have a good effect on EMI noise suppression.

This paper studies the electromagnetic compatibility (EMC) for the instrumentation & control system, communication devices and electric equipments in commercial nuclear power plants (NPPs). It reviews the EMC research activities and practices for NPPs in United States, France, Russia and China. The paper first familiars the readers with electromagnetic interference (EMI) knowledge and examples that are most related to NPP EMC issues, including EMI source, coupling path and sensitive equipment. It then summarizes the historical research activities, focusing on the development of EMC standards for NPPs in those four countries. It is concluded that the current EMC standard systems are not uniform and lack of specific test procedures and quantification methods. They are insufficient for the nuclear industry to execute. At last, recent popular research topics for NPPs are reviewed including systematic EMC design, EMC design and control measures, EMC prediction and electromagnetic environment monitoring. Similar research work done in the general EMC community or by other industries has been introduced. It indicates that for NPPs EMC design especially at the system level is still immature, electromagnetic simulation can be a good tool to assist the EMC design and that EMC control regulations and environment monitoring become more and more necessary as wireless components and devices are being used.

SUMMARY This paper proposes spread-spectrum clock modulationalgorithms for EMI reduction in digitally-controlled DC-DC converters.In switching regulators using PWM, switching noise and harmonic noiseconcentrated in a narrow spectrum around the switching frequency cancause severe EMI. Spread-spectrum clock modulation can be used to min-imize EMI. In conventional switching regulators using analog control it isvery difficult to realize complex spread-spectrum clocking, however thispaper shows that it is relatively easy to implement spread-spectrum EMI-reduction using digital control. The proposed algorithm was verified usinga power converter simulator (SCAT). key words: PWM control, spread-spectrum clock modulation, EMI,digitally-controlled DC-DC converter 1. Introduction Most portable electronic devices have low-voltage high-current power supplies using high-efficiency switching reg-ulators. However, the considerable switching noise (andEMI) that switching regulators produce is a big demerit.EMI-related regulations are becoming more severe [1]. Reg-ulations prescribe limits on the generation of Electromag-netic Interference (EMI) and also noise-tolerance or Elec-tromagnetic Susceptibility (EMS) requirements; the combi-nation of both EMI and EMS is called EMC (Electromag-netic Compatibility). In many countries it is illegal to sellelectrical and electronic devices that do not comply with lo-cal EMC standards (in many cases devices must be type-approved, or tested and certified as complying). In mostconventional switching regulators, shielding and filteringare used to reduce EMI. While shielding and filtering areeffective ways of reducing noise, penalties associated withthis approach include the cost of transformers and coils andthe size/weight of shielding.We considered, as an alternative to extensive shield-ing and filtering, how to reduce EMI by switching regu-lator control-module design changes. After examining thepossible application of digital control systems with spread-spectrum technology [2]–[5] to analog-controlled switching

Using commercial off the shelf (COTS) computing equipment in military aircraft applications may cause harmful electromagnetic interference (EMI) to other on-board systems, including communication and navigation equipment. An electromagnetic compatibility (EMC) design approach to successfully integrate COTS equipment into an existing military aircraft is described. The following system design and development steps are outlined: (1) requirements definition, (2) preliminary EMC analysis, (3) EMC control measure design, (4) COTS equipment EMI characterization tests, and (5) system level EMC verification.

Since January 1996 all manufacturers have to design their equipment to comply with the protection requirements of the electro-magnetic compatibility (EMC) directive 89/336/EEC of the European Commission. The protection requirements define, that the manufacturer has to minimise the probability of causing or suffering from electromagnetic disturbances. Manufacturers of power drive systems (PDS) normally define a rated input voltage range, rated power range as well as a climatic ambient within which the PDS has to operate. The EMC product standard EN 61800-3 for adjustable speed electrical PDS, on the other hand accepts light load or unloaded test condition during the conducted emission measurement according to the emission standard EN 55011. This paper looks at the EMC behaviour of PDS, especially in combination with an input electromagnetic interference (EMI) filter in function of the supply voltage and its real load condition. Investigation shows direct influence of real ambient and load conditions on EMI filter performance. Therefore in many cases passing the EMC tests in laboratory conditions does not mean fulfilling protection requirements in the field.

Conducted electromagnetic compatibility (EMC) noise qualification tests are normally carried out after a prototype has been designed, built and tested and the process is repeated in the event of non‐compliance. The ability to determine compliance with electromagnetic interference (EMI) standards at the design stage is therefore desirable. This study will present conducted EMC noise modelling and measurement techniques, yielding simulated and measurement noise results accurate enough to serve as a prequalification test at the design and prototyping stages, respectively. Accurate models of the power feed line connecting the line impedance stabilisation network to the device under test (converter), including the load are developed. Predictive conducted EMC modelling is accomplished using detailed active level 3 SPICE‐based models, creating a real‐time circuit model consisting of a complete converter in its operational state, without the need to separate into equivalent models. Effects of the power feed‐line length on EMI noise measurements are investigated as currently available literature has not dealt adequately with this issue. The modelling and measurements are performed using software and instruments available in a development laboratory..

The Liquid Crystal Display (LCD) module in a high power TEA CO2 laser is easy to couple with electromagnetic interference, so as to affect the normal work of the laser. Therefore, this paper explores the prediction method of Electromagnetic Compatibility (EMC) for the LCD module under transient irradiation in an electromagnetic field. The coupling mechanism of electromagnetic interference received by the LCD module integrated in the laser system was analyzed. On the basis of the coupling of field and line, the field line electromagnetic interference of the LCD module was analyzed and calculated by using the BLT equation in the Taylor form, then, the prediction results were verified by several experimentally. The experimental results show that the interference voltage produced by connect cables coupled with electromagnetic fields on the data lines of LCD display module is 1 V, and exceeds the noise margin of the circuit. So the EMC control measures must be taken to ensure the performance of the LCD module. Moreover, the verification experiments indicate that prediction results for the EMC has correctly reflected the actual EMC performance of LCD module. The method has a guiding significance for prediction and design of EMC of electrical equipment in high-power TEA CO2 lasers.