Testing for EMC (electromagnetic compatibility) in the clinical environment.

The short-circuit current(SCC) is far larger than the rated current of existing circuit breakers, which has been a serious problem threatening the safety of the power grid. The economical high-voltage AC current limiter based on high coupled split reactor(HCSR) and rapid switch can be used to suppress the SCC. In this paper, the composition structure and working principle of the limiter are introduced at first. The main source of electromagnetic interference(EMI) in the system is explained then. In order to improve the reliability of the economical limiter and also to reduce the interference from its own, both electromagnetic compatibility(EMC) immunity tests and EMC emission tests should be done. As there is no testing standard basis for this new type of limiter, this paper gives the EMC test requirements, test methods and test criterion. According to different EMC tests and tested port types, specific test parameters and test procedures are given as well. At the end of the paper, the practical anti-interference measures are given to ensures the reliability of the design. Beyond that, however, this paper also offers reference for establishing testing standards of the economical high-voltage AC current limiter.

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.

Protecting COVID-19 Vaccine Transportation and Storage from Analog Cybersecurity Threats

To bring automotive integrated circuits (ICs) to market, manufacturers must subject their products to numerous electromagnetic compatibility (EMC) tests such as electromagnetic immunity and emission tests, or electrostatic discharge (ESD) tests. These tests need EMC test boards that meet the requirements of the specific standards. However, the current need to increase the frequency range of EMC tests poses a challenge in designing standard-compliant test boards. In this paper, we address this issue by introducing a modular and reusable IC level EMC test system. We demonstrate the system’s effectiveness with an example of two frequently used and conducted EMC tests: the direct power injection (DPI) immunity test and the 150Ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$150\\,\\mathrm{\\Omega}$$\\end{document} electromagnetic emission measurement. The two test setups are constructed and validated using the presented modules. It is shown how the frequency range can be expanded while minimizing costs and design efforts for the EMC test board design.

A calculation method of electromagnetic interference(EMI) margin of spacecraft wireless system is analyzed and researched in this paper, meanwhile the EMI margin is simulated and calculated. The electromagnetic compatibility (EMC) of wireless system is prognosed for a couple of wireless equipment which indicate that there is a risk of EMI among this couple of wireless equipment. According to the simulation results, a series of EMC test including tabletop dispersedly test and comprehensive test has been implemented to verify the prediction method. The test results indicate that there is EMI phenomenon among this couple of wireless equipment which support the accuracy of the prediction method. Combined with simulation and test results, a method for spacecraft wireless system EMC prediction has been proposed. The method will reduce the EMI problem in spacecraft development process and be benefit to subsequent maintenance.

Review of EMC standards for Underwater Vehicles

The identification and localization of large-range, wide-band electromagnetic interference (EMI) sources have always been both costly and time-consuming. The measurements at different times and places are often required before a typical system can locate a target. In this paper, we proposed a 2D electromagnetic imaging system to localize interference sources and identify the EMI frequency in real time. In this system, an offset paraboloid with a diameter of three meters is designed for large-range EMI imaging, while a multi-channel digital signal acquisition system is developed for wide-band EMI localization. The located interference source is segmented by the maximum entropy method based on particle swarm optimization, and the modified generalized regression neural network (MGRNN) is applied to identify the EMI frequency effectively by excluding misleading effects of outliers. The experiment which has been completed on our dataset indicates that our approach not only increases accuracy by 5% compared with the standard generalized regression neural network approaches for identification, but also exerts a large-range wide-band localization of the EMI source detection method.

In this paper, common mode (CM) and differential mode (DM) far-field radiation models of a typical digital inverter with cables are built up to predict electromagnetic field strength and analyze field characteristics. The CM current model and its analyses are based on the imbalance difference method. It is found out that the voltage between the drain and the source electrodes of upper transistor is the key equivalent source of electromagnetic interference (EMI). Far-field radiation strength of the digital inverter in free space is predicted by using the asymmetrical antenna radiation method and current loop radiation method. The accuracy of these methods is verified by the CST electromagnetic simulation results in the frequency range from 1 MHz to 400 MHz. Furthermore, the radiation models are improved by using the mirror method, which enables to include the reflection effect of the metal ground plane at the electromagnetic compatibility (EMC) test site. Both the results of measurements in a semi-anechoic chamber and the simulation results confirm the proposed electromagnetic radiation prediction method.

For the deployment of Wireless Sensor Networks (WSN) in nuclear reactor environment to monitor and measure the plant parameters, the WSN nodes should be rugged, able to withstand high temperature, radiation and should be qualified in the environmental tests, Electromagnetic compatibility (EMC) and seismic tests as per the international standards. Hence Industrial grade wireless sensor networking nodes which meet the required specifications have been designed and developed. The nodes after successful development and functionality testing have been subjected to EMC tests at EMI/EMC Lab in Indira Gandhi Centre for Atomic Research (IGCAR). Subsequently they have been successfully qualified for EMC tests at SAMEER (Society for Applied Microwave Electronic Engineering and Research), chennai. This paper describes briefly about the design and development of nodes, measures taken for EMC qualification of nodes, qualification tests done and the test results.

This paper discusses the design and testing of the lasers built for the Clementine Laser Rangefinder that was used to map the lunar topology. a baseline Acceptance Test Procedure (ATP) was run once and the flight laser was built. Then the Laser Resonator Assembly (LRA) and the Laser Power Supply (LPS) were subjected to vibration and electromagnetic compatibility (EMC) testing as well as a 50 hour Thermal Vacuum test (T- VAC). Laser energy and boresight stability was checked after each vibration axis and after EMC testing. A complete ATP was run again after all environmental tests were completed, results were compared to baseline.

This paper addresses improved electromagnetic compatibility (EMC) in switched-mode power converters (SMPCs), without using electromagnetic interference (EMI) filters. A practical solution is proposed for minimizing conductive EMI in a pulsewidth modulated (PWM), and random PWM dc-dc power converters. A comparative investigation is performed into the use of different random modulation schemes (driven by the DSP-2 board with the TMS320C32) as against the normal PWM. The effectiveness of randomization on spreading those dominating frequencies that normally exist in constant frequency PWM schemes is evaluated by power spectral density (PSD) estimations in the low-frequency range. Some parasitical- and topology-based EMI sources in devices are presented and frequency analysis is shown by using the discrete Fourier transform (DFT). SPICE simulations are also used to verify practical solutions for eliminating negative EMI sources and achieving EMC improvements. Finally, levels of conductive EMI are estimated with DFT, and experimentally verified to comply with the CISPR 25 (or EN 55025) regulations. Moreover, it is clearly shown, that limited speed PWM driving of the power switches with appropriate snubber circuits guarantees reduced conductive EMI. When considering the price and high EMC, in the final solution the power converter is driven by the mu-controller PIC16F876 with limited numerical and peripheral capabilities, where only normal PWM and randomized PWM can be implemented

Radiofrequency (RF) sources in the non clinical environment can expose medical devices to field strengths that exceed several volts per meter Electric (E) field strengths were measured at typical usage sites for home or ambulatory medical devices. Isotropic, broadband E field probes and calibrated antennas with spectrum analyzers were used. Three distinct categories of RF source/exposure situations were identified: Distant Transmitters includes high power radio and television broadcast transmitters. These can produce field strengths that are greater than 3 V/m at distances greater than 500 meters from the broadcast antenna. Local Transmitters such as 25-100 watt transceivers in emergency vehicles can produce exposure field strengths of more than 3 V/m up to 10 meters from their antenna. User Handheld Transceivers such as handheld cellular phones and security guard transceivers radiate 0.6 to 7 watts and produce field strengths that can exceed 3 V/m at distances of over 3 meters. These field strengths all equal the minimum 3 V/m immunity level specified in the prevailing IEC-601-1-2 international medical device electromagnetic compatibility standard. >

This paper presents the calibration of pulse generator according to International Special Committee on Radio Interference (CISPR) 16-1-1 standard using Fast Fourier Transform (FFT) technique for Electromagnetic Compatibility (EMC) Testing. The pulse generator is configured to source a pulse signal for each CISPR frequency band A, B and C respectively and the signal is then split into two paths using a splitter. A delay line is inserted into one path of them as a trigger signal to allow the sampling head of digital sampling oscilloscope to capture the signal from the other path. After that, the data is recorded and transferred to the computer using Labview software via a GPIB interface. This signal waveform is now analyzed using FFT and calculated on Matlab to compare with the standard. Finally, the calibration results are shown with uncertainty budget.

For extended critical infrastructures such as the power grid, electromagnetic compatibility (EMC) testing of electronic components alone is not sufficient to assess the risk of electromagnetic (EM) attacks. This paper presents results on a methodology for high-power EM based risk assessment of large structures considering the example of smart grid substations. The evaluation involves control, protection, and communication equipment used in substations as part of supervisory control and data acquisition systems and ready for the smart grid. The methodology developed in this paper evaluates the threat, vulnerability, impact, and protective measures as indicators in various scenarios of both conducted and radiated intentional EM interference (IEMI) threats to these systems. In order to assess these indicators, fundamental data on available IEMI sources, generic substation layouts, and their mitigating effects, coupling paths, and IEMI susceptibilities has been gathered in several test campaigns and studies. Electrical field strengths generable by commercially available power sources inside substations have been estimated considering measured shielding characteristics of the buildings and attainable target distances. A comparison with measured susceptibilities of control equipment to IEMI reveals noticeable security issues. In particular, expected field strengths inside substation buildings can be much higher than the immunity levels for control systems as requested in EMC standards.

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.