International Special Committee Research Articles

Research on characteristics of radio interference of MMC-HVDC lines

Abstract Previous research on radio interference in DC lines has focused on radio interference caused by corona discharge. But with the development of Modular Multilevel Converter Based High Voltage Direct Current (MMC-HVDC) systems, high frequency signals generated by fast switching of Insulate-Gate Bipolar Transistor (IGBT) are transmitted to Direct Current (DC) lines and radiate radio interference outward. On the one hand, the radio interference formula recommended by the dual-level DC transmission line recommended by International Special Committee on Radio Interference (CISPR) is calculated by the radio interference generated by the line corona discharge; On the other hand, by establishing a MMC-HVDC line model, analyse the high frequency signal transmission generated by the fast switching of IGBT in the Modular Multilevel Converter (MMC) to the radio interference generated by radiating outside the DC line. The results of the study show that the radio interference generated by high -frequency signals of IGBT fast switching will decrease with the length of the line. The radio interference value generated by corona discharge is 47.43 dB(μV/m), the radio interference generated by the high-frequency signal of IGBT fast switching is 40.83 dB(μV/m), which is too small than the radio interference of corona discharge.

Innovative measurement and noise reduction of voltage coupling in shielded cables for enhanced signal integrity

The reliable transmission of electrical signals through shielded cables in the presence of electromagnetic interference (EMI) remains a critical challenge for signal integrity. This paper presents a novel and comprehensive approach for measuring and reducing voltage coupling in shielded cables connected to a shielded room from a waveguide. Additionally, we introduce an innovative active EMI filter to effectively mitigate common-mode (CM) and differential-mode (DM) noises, thereby enhancing the overall signal quality. To address the issue of voltage coupling, an open circuit method with a transmission line is considered for the measurement of output voltage at the end of the shielded cable. In order to assess the impact of EMI on transmitted signals, we utilize a state-of-the-art noise separator that enables precise differentiation and characterization of CM and DM noise components. This analysis provides valuable insights into the overall noise profile, guiding the subsequent steps toward noise reduction. An active EMI filter was designed to effectively attenuate the unwanted noise. The filter intelligently targets and mitigates both CM and DM noises, resulting in improved signal integrity. The experimental setup encompasses a shielded room, shielded cables, a waveguide, and the equipment. The obtained output voltage from the shielded cable is 495 V. It is given as an input to the equipment (Cuk converter). The noises are generated when the input voltage is given; the noises are separated by using a noise separator. CM noise obtained at the output of an active noise separator is 118.8 dBµV. DM noise obtained at the output of a differential mode noise separator is 115.8 dBµV. With the active EMI filter, we achieve remarkable reductions in CM and DM noise levels. After adding a filter to the circuit, the noises are reduced below the limit line according to the International Special Committee on Radio Interference standard; the CM noise is 44.8 dBµV and the DM noise is 47.8 dBµV.

A Test Setup to Assess the Impact of EMI Produced by On-Board Electronics on the Quality of Radio Reception in Vehicles

Radio performance is very important in the automotive industry. It is necessary to provide a careful assessment of radio reception of each vehicle project development. It is well known that the vehicle radio performance may be affected by electromagnetic interferences from the components of the vehicle itself. These interferences degrade the radio signals and prevent the on-board receiver from retrieving correctly the baseband signal. Generally, the car manufacturers rely on the international special committee on radio interference (CISPR) 25 standard to decide whether radio reception tests pass or fail according to the interference limits set in advance. However, although the standard is able to detect interferences and determine their type and level according to various detectors, their consequence on radio reception quality (if any) cannot be assessed in a quantitative manner. This is even more difficult with digital communication systems such as digital analog broadcasting (DAB). For the time being, the final quality of the radio reception is evaluated in a totally independent way, through driving tests. This article introduces an improved test setup that performs both interference level measurements and assessment of the radio reception performance. Two operating modes are described. They are based either on the conducted or the radiated injection of the transmitted radio signal. Although dedicated to analog and digital transmissions, we will deal only with the analog radio (FM) in this article. From a set of experiments, we conclude that interferences measured with average detectors are more likely correlated to radio reception issues.

Electromagnetic Interference Characteristics and Reduction Using CISPR11 for a Medical Light Emitting Diode Drive DCDC Buck Converter

Recently, many low-power LED (Light Emitting Diode) lighting fixtures that can contribute to a low-carbon society have been installed in clinical settings. However, since Alternating Current (AC) voltage cannot be used directly for LED devices, Direct Current (DC) voltage must be applied LED devices. For this reason, it is necessary for the LED equipment to install an ACDC power converter. A buck converter as an ACDC power converter is applied to the LED equipment, but Electromagnetic Interference (EMI) radiated from it has a strong influence on the wireless communication of a medical place. In particular, EMI radiated emission to medical telemeter systems using wireless communication becomes a significant problem of biomedical signal discontinuations. To investigate the EMI radiated strength, it must be measured using CISPR11 medical equipment international standard (International Special Committee on Radio Interference) on Limits and methods of measurement. This paper is focused on the LED drive DC power converter EMI radiated emission. The CISPR11 measurement EMI disturbance characteristics when a buck type current control DCDC buck converter circuit is used for the lighting of an LED device are shown. It is reported experimental results of EMI radiated emission characteristics improvement by changing the input and output circuit constants of the proposed circuit. Moreover, it is shown that can reduce to the floor noise level (background noise) when an output capacitor is inserted without an input filter.

Consideration to Terminating Condition of Mains Cable for Radiated Emission Measurement Caused by Different Disturbance Sources

Very high frequency (VHF)-line impedance stabilization network (VHF-LISN), which is defined as the termination device for mains cable of equipment under test to specify the input impedance of each line at the mains power supply outlet, can improve correlation between test sites that perform radiated emission measurement. Balanced and unbalanced types of VHF-LISN are currently under proposal with International Special Committee on Radio Interference (CISPR) as a device for prescribing the terminating condition of the power supply cable. Simulation analysis with common mode (CM)/differential mode (DM) signal sources was performed to investigate the emission characteristics with the two types of termination devices under several measurement arrangements that used two-wire and three-wire mains cables. Furthermore, to confirm the validity of the simulation analysis, measurement of a versatile comb-generator-operated by ac mains was performed under the same test arrangement and two types of termination devices. Quasi CM/DM signal from an ac-operated comb generator was injected back into the mains cable of the same comb generator. This article explains how we ascertained the radiated emission characteristics with each termination device, and provides guidance for their appropriate usage.

Effectiveness Assessment of a Nanocrystalline Sleeve Ferrite Core Compared with Ceramic Cores for Reducing Conducted EMI

The interconnection of different electronic devices or systems through cables is becoming more difficult due to the hard restrictions related to electromagnetic compatibility (EMC) in order to comply with requirements. Therefore, the use of EMC components is a good solution to manage the problems associated with the filtering of electromagnetic interference (EMI) in cables and to pass the compliance test. In this sense, sleeve ferrite cores become a very interesting solution since they can be set around a wire and, hence, they provide an effective solution against EMI without having to redesign the electronic circuit. This contribution is focused on the characterization of the performance of a sleeve ferrite core based on a novel nanocrystalline (NC) novel material for EMI suppression and comparing it to the most conventional ceramic ferrite cores such as MnZn and NiZn. The research highlights the suitability of an NC novel component in terms of its magnetic properties to reduce EMI within the conducted emissions range. This range is generally defined by the International Special Committee on Radio Interference (CISPR) test standards frequency band that covers from 150 kHz up to 30 MHz (108 MHz in the case of CISPR 25). First, this study presents a description of the main parameters that define the behavior of NC and ceramic cores and, secondly, by analyzing the data obtained from experimental procedures, it is possible to directly determine the insertion loss parameter. Hence, this characterization procedure is used to obtain the performance of NC material compared to the conventional sleeve ferrite core compositions employed to filter the interferences in this problematic frequency range. As can be deduced from the results obtained, an NC sleeve ferrite core provides the best performance in terms of EMI filtering within a significant frequency range between 100 kHz and 100 MHz.

Pre-Clinical Testing of Microwave Radiometer and a Pilot Study on the Screening Inflammation of Knee Joints.

This article presents the pre-clinical evaluation of our custom-built, single-band microwave radiometer centered at 1.3 GHz for deep tissue thermometry, and a pilot study on volunteers for passive detection of inflammation in knee joints. The electromagnetic (EM) compatibility of the battery-operated radiometer for clinical use was assessed as per International Special Committee on Radio Interference (CISPR) 22 standard. The ability to detect inflammation in knee joints was assessed using a substrate integrated waveguide antenna connected to the radiometer. EM compatibility tests carried out in the laboratory indicated device immunity to intentional radiated interference up to -20 dBm injected power in the global system for mobile communication frequency band, and pre-compliance to CISPR 22 standard. Radiometer temperature measurements recorded at the lateral and medial aspects of both knees of 41 volunteers indicated mean temperature greater than 33°C for the diseased sites compared with the mean temperature of 28°C measured for the healthy sites. One-way analysis of variance statistics indicated significantly (P < 0.005) higher radiometer temperature at the diseased sites unlike the healthy sites. Thus, the EM pre-compliance of the device and the potential to measure deep tissue inflammation were demonstrated. Bioelectromagnetics. 2019;40:402-411. © 2019 Bioelectromagnetics Society.

A New Method for Calibrating Impedance of an Artificial Mains Network With a Vector Network Analyzer

In this paper, an impedance calibration method of an artificial mains network with a vector network analyzer is proposed for determining its conformity to the International Special Committee on Radio Interference (CISPR) 16-1-2 standard. In this method, five transfer standards modeled on CISPR 16-1-2 regulated impedance are used. Traceability to the International System of Units is established using these standards. Impedance-format-based calculations can be performed and impedance magnitude and phase can be independently analyzed using the proposed method. A demonstration is performed in the frequency range of 150 kHz to 30 MHz to validate the method. The expanded uncertainty is 10 % smaller than the tolerance by CISPR 16-1-2.

Reduction in Radiation Noise Level for Inductive Power Transfer Systems Using Spread Spectrum Techniques

Two proposed methods of reducing radiation noise caused by inductive power transfer (IPT) systems using spread spectrum techniques were experimentally demonstrated. In IPT systems for electric vehicles (EVs) or plug-in hybrid EVs (PHEVs), noise reduction techniques are necessary because the radiation noise from the IPT system for EVs or PHEVs must not exceed the limits defined by noise standards, such as the well-known regulation set by the International Special Committee on Radio Interference. In the proposed methods, the radiation noise from the transmission coils of the IPT system is spread in the frequency domain by randomly changing the output frequency of the inverter. The output frequency is selected according to the generation of pseudorandom numbers. In the first proposed method, spread spectrum with a uniform distribution (SSUD), the output frequency is selected from the frequency range of 80 to 90 kHz with an even distribution. In the second method, spread spectrum with a biased distribution (SSBD), the output current of the inverter is considered. The possibility of selecting an output frequency in the given range is biased in proportion to the combined impedance from the transmission coil and the resonance capacitors on the primary side. In experiments with a 3-kW prototype, when SSUD and SSBD were applied, the fundamental components of the radiation noise were suppressed by 4.45 and 8.27 dB · μ A, respectively, in comparison with the noise obtained using the conventional system, which operates the inverter at a fixed frequency.

IEC international special committee on radio interference (CISPR) meets in Vladivostok, Russian Federation

The International Electrotechnical Commission (IEC) national committee of the Russian Federation hosted the annual General Meeting of the IEC where the International Special Committee on Radio Interference (CISPR) had its meeting at the same venue in Vladivostok, Russian Federation. The venue was the Far Eastern Federal University (FEFU) Congress and Exhibition Center on Russky Island. Bettina Funk of the Swedish Post and Telecom Authority chaired the CISPR plenary meeting. The author of this article is a member of the CISPR steering committee and immediate past chair.

Design Method for EMI Filters Connected to Both dc and ac ports of a Residential‐Use Photovoltaic Power Conditioner

SUMMARYElectro‐magnetic interface (EMI) noise radiated from the dc cable of photovoltaic power conditioner systems (PCSs) is a serious problem for radio transmission equipment. In order to prevent the interference, the International Special Committee on Radio Interface (CISPR) is discussing to determine a noise regulation value for this issue. To reduce the radiated noise, this paper studies the attenuation characteristics of EMI filters that are connected to both the dc and the ac sides of the PCS. In this paper, it is pointed out that the EMI filters do not show their own attenuation characteristics if those are connected to the PCS. In particular, when EMI filters are connected to both the dc and the ac sides of the PCS, a specific series resonant frequency is observed and deteriorates the attenuation characteristics of both EMI filters. In order to prevent this problem, a design method for EMI filters which can reduce the common‐mode EMI noise effectively, is proposed in this paper. Further, the effectiveness of the proposed method is confirmed through experiments.

Radio interference excitation function of conductor bundles based on cage test results and comparison with long‐term data

A reasonable excitation function is vital to make a precise evaluation about the radio interference (RI) level of ultra-high-voltage (UHV) AC power lines. To obtain this function, a large number of RI measurements in heavy rain condition were done using different conductor bundles in a corona cage. Then, the excitation function in heavy rain condition was obtained by least-square fitting these measured values. After that, the validity of this function was verified with the statistical data measured from the Hubei long-term station, which is located under the operating 1000 kV Jindongnan–Nanyang–Jingmen UHV AC transmission lines. It turns out that the deviation between the prediction and the long-term average value is 1.1 dB in heavy rain condition, and 1.3 dB in fair weather condition. In addition, the long-term data measured in Hubei Station show that the conversion laws of RI at different weather conditions in International Special Committee on Radio Interference (CISPR)18 are also applicable to 1000 kV UHV transmission lines.

The Input Impedance of Common-Mode and Differential-Mode Noise Separators

This paper discusses the $\Delta$ -networks and other circuits designed to separate the conducted electromagnetic interference (EMI) into its common mode (CM) and differential mode (DM) components. The input impedances of CM/DM separators must be 50 $\Omega$ resistive in the measurement frequency range, and they must be independent of the values of the noise signals and noise source impedances. The conditions for achieving such input impedances are derived. It is shown that many of the proposed separators, including the $\Delta$ -network suggested in the International Special Committee on Radio Interference (CISPR) 16-1-2 standard, do not fulfill the input impedance requirement. This leads to unreliable CM and DM measurements and, consequently, to the oversizing of EMI filters and design by trial and error.

家庭用太陽光発電用パワーコンディショナの入出力EMIフィルタ設計手法

Electro-magnetic interference (EMI) noise radiated from the DC cable of photovoltaic power conditioner systems (PCS) is a serious problem for radio transmission equipment. In order to prevent the interference, the International Special Committee on Radio Interference (CISPR) is discussing to determine a noise regulation value for this issue. To reduce the radiated noise, this paper studies the attenuation characteristics of EMI filters that are connected to both the DC- and the AC-sides of the PCS. In this paper, it is pointed out that the EMI filters do not show their own attenuation characteristic if those are connected to the PCS. In particular, when EMI filters are connected to both the DC- and AC-sides of the PCS, a specific series resonant frequency is observed and deteriorates the attenuation characteristics of both EMI filters. In order to prevent this problem, a design method for EMI filters which can reduce the common-mode EMI noise effectively, is proposed in this paper. Further, the effectiveness of the proposed method is confirmed through experiments.

30MHz 이하 무선 서비스에 대한 전자기기의 잠재적 간섭 영향

This paper analyzed a potential interference of electric equipments on radio service below 30MHz through an experiment with a PDP(Plasma Display Panel) TV and a RF(Radio Frequency) light bulb in an anechoic chamber. The radiation levels of the PDP TV and the RF light bulb are measured and a combined interference is calculated on the basis of the experimental value. As a result, the combined interference signal level is increased according to the number of interferer. The possibility of a potential interference from electric equipments on radio service below 30MHz is realized through comparison between the measured radiation value of electric equipments and the CISPR(International Special Committee on Radio Interference) 11 limit.

Canada welcomes CISPR, TC77 and TC106!

The 2013 meeting of the International Special Committee on Radio Interference (CISPR) was held this year in Ottawa, Canada. The meeting was sponsored by the Canadian National Committee of the International Electrotechnical Commission (IEC). CISPR is a technical committee of the IEC. In parallel, TC77 (EMC) met as well as TC106 (Human Exposure). This article will describe the CISPR meetings.

Validation of emission measurement site above 1 GHz

[1] The International Special Committee on Radio Interference (CISPR) (CISPR 16-1-4) measured the site voltage standing wave ratio (SVSWR) to determine the site imperfections of a radiated emission measurement site above 1 GHz. However, the technical background of the SVSWR measurement parameters is not included in this standard. In this paper, we first propose a simple propagation model to evaluate the relation between the SVSWR parameters and the measurement values. The calculated SVSWR values of the total displacement defined in CISPR 16-1-4 (0.4 m) were almost the same as those obtained when the transmitting antenna was moved up to 2.0 m from the reference point. In addition, the SVSWR values obtained with a 50 MHz frequency resolution, as defined in CISPR 16-1-4 were almost the same as those values obtained with a 1 MHz resolution. From these results, we confirmed that the CISPR measurement parameters are reasonable and effective.

Compatibility between ISM Equipment and WiBro Service at 2.3 GHz band

This paper calculates protection distance to protect WiBro service from ISM(Industrial Scientific Medical) equipment which is used in the same frequency with WiBro. We analyze with a scenario that WiBro receiver is closed to ISM equipment which has interfering power of CISPR(International Special Committee on Radio Interference) 11 limit. As a result, the protection distance of 14 m was calculated by using MCL (Minimum Coupling Loss) for the worst case. And, the protection distance of 10 m was calculated to meet 5 % interference probability below by using MC(Monte Carlo) for statistic analysis in case of a interferer.

CHANNEL CAPACITY OF HIGH-SPEED POWERLINE COMMUNICATION IN VEHICLES

Powerline Communication (PLC) Systems intents to use the mains network in vehicles for high-speed data transmission. Carrier frequencies in the range of MHz are required to establish data rates of some megabits per second. In this paper, typical reference channels extracted from channel measurements are presented and computation results of their capacities according to Shannon’s theorem are presented. Furthermore, the effect of limitations of frequency range and power spectral density of transmitted signal on achievable capacity is investigated. This paper outlines an assessment for theoretical channel capacity and achievable data rates of vehicular PLC transmission schemes. Finally, EMC (Electromagnetics Compatibility) constraint according to CISPR 25 (Comite International Special des Perturbations Radioelectrique – The International Special Committee on Radio Interference) is deeply considered.

Uncertainties in 3-m Radiated Emission Measurements Due to the Use of Different Types of Receive Antennas

This work describes the results of an investigation into uncertainties in radiated emission measurement results due to the use of different receive antennas. These antennas are used during electromagnetic-compatibility tests of products which must comply with regulatory radiated emission requirements. In the past few years, the standardization International Special Committee for Radio Protection (CISPR) Subcommittee A (SCA) has tried to improve the radiated emission measurements by quantifying most of the uncertainty sources. We deal with the uncertainty due to the free space antenna factor's inability to fully specify the antenna properties at frequencies up to 1000 MHz. We have simulated and measured the radiated emission of an equipment-under-test (EUT) using various types of receive antennas. The simulated radiated emission measurement results using a biconical antenna give a maximum difference of 1.2 dB in relation to the use of a tuned dipole. The use of bow-tie antennas leads to a radiated emission difference of maximal 2.5 dB in relation to the tuned dipole. Finally, the use of a log-periodical antenna leads to a maximum deviation of 2.8 dB in relation to the tuned dipole. This means that the uncertainty caused by using different types of receive antennas in 3-m radiated emission measurements may be significant, so the presented uncertainty budgets in CISPR 16-4-2 should therefore be reconsidered and expanded.