Common-mode Filter Research Articles

Design and Fabrication of a novel wideband common mode noise suppression filter using fuzzy interpolation method

This article proposes two new wideband common-mode noise suppression filters based on a defected ground structure. The first design uses the Butterworth equivalent circuit achieving a fractional bandwidth of 117 %. At first, the resonators are arranged next to each other and the equivalent circuit is extracted. Also, samples with different dimensions of resonators are prepared by electromagnetic simulation analysis, and the fuzzy interpolation method is used for estimating the circuit behavior. The ADS software is used to optimize the values of the variables to achieve the desired bandwidth in the schematic environment. This paper utilizes the Taguchi method to strike a balance between various parameters in the filter design, aiming to minimize errors during the fabrication process. Then, the new values estimated with the fuzzy interpolation method are verified by electromagnetic simulation. The fractional bandwidth of the filter increases to 124 %, and noise can be suppressed by more than 10 dB at the center frequency of 21.45 GHz in the range from 8.1 to 34.8 GHz, with a loss of less than 3 dB in the differential lines. A new equivalent circuit is proposed using the first-order Chebyshev model. It is observed that the electromagnetic simulations and circuit modeling have good agreement with the measurements. Moreover, the eye pattern with a speed rate of 21.45 Gb/s is proposed for USB 3.2 and HDMI 2.0 applications.

A nondestructive high-resistance fault diagnosis method of XLPE medium voltage cables based on Chirp-TDR

Diagnosing and locating the high resistance fault (HIF) of XLPE medium voltage cables without causing secondary damage has been a trouble for power maintainers. Among the previous methods proposed by researchers, the frequency domain reflection method has the strongest sensitivity, which still cannot meet the broad dynamic range requirement of HIF detection. This paper proposes a chirp-TDR high resistance fault detection method, which fully taps the signal processing gain of the chirp signal after pulse compression. The method increases the practical detection limit to hundreds of kΩ. A prototype is implemented, and the performance is simulated. The influence of incidence and terminal reflection signals on fault point reflection signal detection is reduced by common mode filtering and access matching impedances. The selected detection signal with 5 ms duration and 20 MHz bandwidth can produce a signal processing gain of 50 dB. A signal coaxial cable and an XLPE power cable with artificial simulated defects were installed as test specimens. The test results show that the method is feasible and has strong anti-noise ability. The technology is compared with FDR, which also uses the chirp signal. The proposed method has a performance improvement of about 12 dB, showing better fault point resolution ability.

Design of Absorptive Common-Mode Filters Based on Coupled Stripline λ/4 Resonator

Design of Absorptive Common-Mode Filters Based on Coupled Stripline λ/4 Resonator

Research on Analysis and Suppression Methods of the Bearing Current for Electric Vehicle Motor Driven by SiC Inverter

The silicon carbide (SiC) inverter brings great advantages to the motor drive systems of new energy vehicles; however, severe challenges to the bearings also happen. The high dc bus voltage and switching frequency of SiC inverter can increase the discharge frequency and energy when the bearing grease film collapses. As a result, the bearing suffers severe electric corrosion, and the service life of the motor drive system can be shortened. In this paper, the characteristics of common-mode voltage and bearing voltage are analyzed, firstly under space vector pulse width modulation (SVPWM). After that, the common-mode equivalent circuit model of the motor drive system is established. The frequency characteristics of bearing voltage are revealed, and the safe working area is determined. Then, the frequency characteristics of bearing voltage and current are verified based on IGBT and SiC inverters in experiments. After that, by designing a common-mode filter, the bearing voltage and current are significantly attenuated. Furthermore, the active zero state PWM (AZSPWM) is adopted to reduce the common-mode voltage from the inverter. At the same time, combined with the common-mode filter, the bearing voltage and current are further reduced. The experimental results show that the switching frequency has a decisive effect on the amplitude of bearing voltage and current. The bearing voltage can be attenuated to around half of the reference bearing voltage by using the common-mode filter and AZSPWM strategy, respectively. The combination of the common-mode filter and AZSPWM strategy can reduce the bearing voltage to around one-fourth of the reference bearing voltage, which can effectively reduce the breakdown time and discharge energy of the grease oil film.

A Novel Common-Mode Voltage Suppression Strategy for Current Source Converter

The problem of common-mode voltage (CMV) in current source converter (CSC) has been concerned with the development and application of CSC, such as in the transformerless motor drive system. Using a common-mode choke is a popular solution to suppressing CMV. The high-frequency harmonics of the CMV can be eliminated by the common-mode filter. However, the low-order harmonics cannot be eliminated effectively, especially at low modulation index, which may cause common-mode resonance and increase the size of the choke. In this paper, a novel virtual space vector modulation (VSVM) method is proposed, which constructs virtual space vectors by the original vectors. The average value of the CMV produced by each virtual vector is zero. The proposed method can reduce the amplitude and third-order harmonic component of the CMV. In addition, the number of switching transitions in a switching sequence of the proposed method is the same as the conventional 5-segment SVM. The suppression effects of different methods on the low-order harmonics of CMV are compared through simulation and experiments, and the effectiveness of the proposed methods is verified.

Mitigating Camera Interference Arising From RF High Transmit Power: The Role of Common Mode Filters and Receiver Compensation Techniques

Mitigating Camera Interference Arising From RF High Transmit Power: The Role of Common Mode Filters and Receiver Compensation Techniques

Measures for attenuation of interference at the level of design of the measuring device of spacecraft

When developing temperature control interface modules used as part of spacecraft onboard equipment, it is important to correctly substantiate the set of measures to ensure their noise immunity, taken at the design levels of the measuring system, measuring device and temperature control interface module. Such a justification involves an assessment of the effectiveness of possible interference mitigation techniques at each design level. The article is devoted to the consideration of interference mitigation measures at the design level of the measuring device, which should be taken to ensure the required noise immunity of the temperature control interface module in combination with measures taken at other design levels. It is shown that in order to ensure the required noise immunity of temperature control interface modules, it is necessary at the design level of the measuring device to provide for measures to mitigate interference in the power supply module, the central instrument module and inter-module interfaces, as well as measures to eliminate gross measurement errors (misses) when processing digital data in the central instrument module. In the power supply module, it is possible to attenuate interference by introducing differential and common mode filters at the input and switching filters at the output. In the central instrument module and inter-module interfaces of the secondary power buses, noise mitigation is possible by dividing the common power bus into analog and digital buses and combining them at an equipotential point. In the central instrument module, it is possible to eliminate misses by using various statistical methods for processing digital data.

Skin Effect and Losses in Soft Magnetic Sheets: From Low Inductions to Magnetic Saturation

High frequencies are ubiquitous in present-day power applications: most electrical equipment, like rotating machines, are supplied by Pulse Width Modulation (PWM) switching inverters, often working at tens or hundreds of kilohertz. PWM is responsible of minor cycles along the major hysteresis loop of the magnetic core, lasting a few microseconds. Such minor loops can cause deep skin effect, even if the thinnest today available laminations (0.1 - 0.2 mm thick sheets) are used. Common mode currents in the megahertz range, flowing from the electrical machine windings to the machine chassis through capacitive effects, can engender strong electromagnetic disturbances and bearing damages. A correct prediction of high frequency phenomena is necessary, for example, for the accurate calculation of common mode filters, requiring a magnetic model of the laminated cores suited to high frequencies and low induction values and the ensuing dramatic skin effect. For power conversion applications, such as embedded planar transformers, the mandatory reduction of volume and cross-sectional area of the core, often made of high-permeability grain-oriented (HGO) sheets, imposes the increase of the conversion frequency from a few hundred hertz to several kilohertz and high peak induction values. The skin effect in this case is affected by the non-linear saturable magnetic response of the material and its treatment requires non-trivial experimental methods and modeling approaches. In this work, we discuss physically based modeling of magnetization process and energy loss in magnetic sheets at high frequencies. We focus first on the low induction regimes occurring in thin non-oriented (NO) Fe-Si laminations. We consider then the case of high inductions, as encountered in power conversion devices using NO, HGO, and Fe-Co alloys, where non-linear models, possibly validated by magneto-optical observations of the domain wall dynamics, are developed and implemented.

Design of performance-weighted blended mode filters for underwater experiments

Normal mode signals are valuable in ocean acoustic tomography and source localization, assuming that they can be separated using spatial or temporal filtering. Common spatial mode filters include the matched filter (MF) [Ferris, JASA, 1972] and the pseudo-inverse (PI) filter [Tindle et al., JASA, 1978]. Choosing a filter and its parameters, e.g., the PI filter rank, requires knowledge that is not readily available. For instance, it is unlikely that the levels of ambient noise or interference from other modes is known a priori. To address this problem, Chakrabarti and Wage [IEEE Oceans, 2021, 2022] developed a Performance-Weighted Blended mode filtering algorithm that adapts quickly to changing conditions and achieves better performance than a single fixed mode filter. The PWB filter blends a set of PI filters of varying ranks, including a rank-1 PI filter (MF). A PI filter can suppress interference from neighboring modes but is more vulnerable to noise than the MF, which has the maximum white noise gain. This talk explores practical aspects of the PWB implementation, including how to select the set of filters to blend given realistic underwater noise conditions. We will show experimental and simulated data to illustrate performance in different environments. [Work supported by ONR.]

Passive CM Filter Configuration for a Multistage Grid-Tied Solid State Transformer

<bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">This work proposes a common mode (CM) filter configuration for a grid-tied two-stage AC/DC solid state transformer (SST). The proposed CM filter utilizes passive components along with the heat-sinks of the individual power converter stages to mitigate the overall conducted emissions (CE) injected by the SST system into the grid. The working principle of the proposed CM filter is analyzed and elucidated using CM equivalent circuit models. In addition to CE reduction with the proposed CM filter, it is also demonstrated that the heat-sinks of the SST system can be closer to ground-potential while being impedance grounded. The effectiveness of the proposed CM filter is validated by experimentally measuring the CE of the grid-tied SST system using a Line Impedance Stabilization Network (LISN).</b>

An Improved Asymmetric Modulation of Current-Source Rectifier With CM Filter for Low Voltage Stress on Switching Devices

Common mode (CM) filters are usually utilized in high power density three-phase current source rectifier (3ph-CSR) to suppress the CM noise in the input currents. However, when CM filters are utilized, the inductor currents at the positive and the negative ends of the DC side of 3ph-CSR are unequal, which brings high voltage stress on switching devices. To reduce the voltage stress on the switching devices, an improved asymmetric modulation is proposed in this letter. In the proposed asymmetric modulation, two switching devices are always turned on in each sector, which clamps the voltage of the switching devices to the peak of the input line voltages. A 1kW experimental prototype of the 3ph-CSR is built to verify the analysis results.

Enhanced Three-Phase AC Common-Mode Filter With Optimized Damping Network for VFDs

This paper presents a highly integrated three-phase AC common-mode (CM) filter with optimized damping network for low voltage, high current motor drive applications. Simplified reduced order models and design guidelines for tuning of RLC parameters are proposed. A single turn AC-CM inductor can be realized using the proposed circuit and design technique, due to lower magnetizing inductance requirement. The RC network is found to provide 50% higher attenuation to peak CM currents compared to a conventional AC inductor alone. At the same time, the peak-volt-second across the CM inductor can be reduced, which is critical for weight sensitive applications. A trade-off between AC-CM inductance and damping resistor losses is evaluated to extract the desired optimal RLC parameters of the AC filter. The proposed circuit is designed and verified with high power <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SiC</i> -based Three Level T-type inverter.

A Compact Broadband Common-Mode Suppression Filter That Integrates Series-Mushroom into Defected Corrugated Reference Plane Structures.

This paper proposes a common-mode noise suppression filter scheme for use in the servers and computer systems of high-speed buses such as SATA Express, HDMI 2.0, USB 3.2, and PCI Express 5.0. The filter uses a novel series-mushroom-defected corrugated reference plane (SMDCRP) structure. The measured results are similar to the full-wave simulation results. In the frequency domain, the measured insertion loss of the SMDCRP structure filter in differential mode (DM) can be kept below -4.838 dB from DC to 32 GHz and can maintain signal integrity characteristics. The common-mode (CM) suppression performance can suppress more than -10 dB from 8.81 GHz to 32.65 GHz. Fractional bandwidth can be increased to 115%, and CM noise can be ameliorated by 55.2%. In the time domain, using eye diagram verification, the filter shows complete differential signal transmission capability and supports a transmission rate of 32 Gb/s for high-speed buses. The SMDCRP structure filter reduces the electromagnetic interference (EMI) problem and meets the quality requirements for the controllers and sensors used in the server and computer systems of high-speed buses.

Design of a Novel Ultra-Wideband Common-Mode Filter Using a Magnified Coupled Defected Ground Structure

An ultra-wideband common-mode (CM) filter for a gigahertz (GHz) data rate signal is proposed in this paper. The proposed filter was designed only on the printed circuit board (PCB) ground plane; no additional components wererequired. We took advantage of producing second-order transmission zero by an asymmetrical magnified coupled DGS to extend the suppression bandwidth. Full-wave simulations and equivalent circuit models of the DGS resonator were established to predict the suppression performance. The measured differential-mode insertion loss (Sdd21) from direct current (DC) to 12.35 GHz was obtained within the −3 dB definitionin the frequency domain. The CM noise was suppressed by more than10 dB in the frequency range from 2.9 GHz to 16.2 GHz. The fractional bandwidth (FBW) reached 139.3%. The proposed filter blocked 62.3% of the CM noise magnitude in the time domain measurement. In addition, the eye diagram measurement proved that good transmission quality was maintained. The proposed filter can be widely implemented to reduce electromagnetic interference (EMI) in radio frequency (RF) andWi-Fi (wireless fidelitystandard) 5 and 6E wireless communication applications.

Integrated Common-Mode Filter for GaN Power Module With Improved High-Frequency EMI Performance

While the employment of wide bandgap (WBG) devices in high-frequency and high-voltage applications brings benefits such as reduced system size and improved efficiency, it aggravates the electromagnetic interference (EMI) issue due to fast switching. High-frequency EMI noise suppression relies mainly on the filter design, where the filter's performance is strongly affected by parasitics. Through analyzing the common-mode (CM) equivalent circuit of a half-bridge power module, this letter identifies the key parasitics that dominate the performance of a common-mode filter (CMF) at high frequencies. To minimize the parasitics, the concept of integrating the CMF inside the WBG power module package is developed to improve the noise attenuation. A π-type CMF is integrated with a half-bridge GaN-based power module as a prototype to validate the concept. Experiments are conducted by measuring the CM noise spectrum received by the line impedance stabilization networks (LISNs) from the hard switching of the designed power module under 70 V and 80 kHz. Comparing the measured results of the integrated CMF to the externally-added CMF, up to 50 dBμV more attenuation is achieved by the integrated CMF in the frequency range of 10 MHz to 100 MHz, verifying the theoretical analysis and the established CM equivalent circuit.

A Selective Common Mode Noise Mitigation Method Using Phase-Shifted Modulation for Four-Switch Buck–Boost DC/DC Converter

Wide bandgap (WBG) power devices can work at higher switching frequencies compared to silicon competitors. It helps reduce the volume of passive components but brings more serious electromagnetic interference (EMI) noise issue. The increased noise filtering requirements may restrict the power density improvement. This study discusses the conducted EMI issue and noise filtering in the four-switch buck-boost DC/DC converter (FSBB). The differential mode (DM) and common mode (CM) noise model embedded with noise sources features are derived and analyzed. It is found that modifying the spectral distribution of the CM noise is a challenge when the duty cycles are fixed by voltage gain. Inspired by the CM model, a phase-shifted modulation method is proposed to achieve selective CM noise mitigation. The recommended operating range and the implementation process are presented. The theoretical modeling and the proposed method are verified through a FSBB converter with 48V input and 100kHz switching frequency. And experimental results validate that the proposed method can achieve 30% volume reduction of the CM filter.

Glide Symmetry Applied to the Design of Common-Mode Rejection Filters Based on Complementary Split-Ring Resonators

In this paper, glide symmetry is applied to design common-mode rejection filters based on defected ground structures with bandstop response. To this aim, complementary split-ring resonators are chosen as the basic components for common-mode rejection. To illustrate the advantages of using glide symmetry, three implementations are studied and compared. The results reveal that glide symmetry offers the best performance in terms of common-mode rejection level and fractional bandwidth. Furthermore, glide symmetry barely affects the integrity of the differential mode. A prototype of each of the considered symmetries has been designed, simulated, and tested for practical validation. Good agreement is observed between the simulated and measured results, experimentally demonstrating the advantages of glide symmetry.

All‐SiC 99.4%‐efficient three‐phase T‐type inverter with DC‐side common‐mode filter

AbstractThis letter presents a hardware demonstrator of an all‐SiC three‐level T‐type (3LTT) inverter with the common‐mode (CM) EMI filter stages placed on the DC input instead of the AC output side, targeting, for example, high‐efficiency PV applications. The extensive experimental characterization shows that state‐of‐the‐art SiC transistors and a DC‐side CM filter enable an unprecedented peak/full‐load efficiency of 99.4% (calorimetric measurement) at 12.5 kW and a power density of 2.4 kW/dm3(39 W/in3). The demonstrator fulfills CISPR 11 Class A EMI regulations as well as upcoming EMI standards for the frequency range of 9–150 kHz. Compared to other high‐efficiency converters, which often employ bridge legs with more output voltage levels, the described 3LTT concept thus offers a very favorable trade‐off between complexity and performance.

A Compact Bandwidth and Frequency-Range Reconfigurable CM Filter Using Varactor-Loaded Dual-Slot-Based Defected Ground Structure

A reconfigurable common-mode (CM) filter with a wide tunable bandwidth and frequency-range is proposed in this article. The filter adopts four compact dual-slot-based defected ground structure (DGS) cells to achieve a wide suppression of CM noise. To simplify the design, only one varactor and one dc-blocking capacitance are loaded on one DGS cell directly, which retains the original structure of the DGS cell. A wide continuously adjustable frequency range and bandwidth can be achieved when different voltages are applied to different varactors. A dynamic equivalent circuit model is built to explain the filter's working principle, which is helpful to obtain the filtering characteristics under different varactor parameters quickly and accurately. In order to verify the feasibility of the scheme, a DGS-based filter with an area of 19 mm × 9.2 mm is implemented under the microstrip line. The simulated results show the filter can achieve a continuously tunable CM suppression of frequency range from 1.9 to 7.3 GHz, and a tunable bandwidth using different voltage supplies. Good agreement between full-wave simulation and measured results is observed.

A Compact Sixth-Order Common-Mode Noise Suppression Filter Based on 3-D Integration Technology

Based on three-dimensional (3-D) integration technology, a compact sixth-order common-mode noise suppression filter is proposed according to delay line theory. As the important parts of the filter, the on-chip inductors are established by through-silicon vias (TSVs) and the capacitors are realized by double layer interdigital structure. Compared with other relative literatures, the proposed filter has a minimized size of 0.29×0.32 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (0.0203 × 0.0224 λg <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ). And it can suppress the common-mode noise more than 10 dB from 3.8 to 8.6 GHz or more than 20 dB from 4.45 to 7.85 GHz. Meanwhile, the differential signal insertion loss is kept less than 3dB.