Showing papers on "Electronic filter published in 2015"

Low-power, chip-based stimulated Brillouin scattering microwave photonic filter with ultrahigh selectivity

Abstract: Highly selective and reconfigurable microwave filters are of great importance in radio-frequency signal processing. Microwave photonic (MWP) filters are of particular interest, as they offer flexible reconfiguration and an order of magnitude higher frequency tuning range than electronic filters. However, all MWP filters to date have been limited by trade-offs between key parameters such as tuning range, resolution, and suppression. This problem is exacerbated in the case of integrated MWP filters, blocking the path to compact, high-performance filters. Here we show the first chip-based MWP bandstop filter with ultrahigh suppression, high resolution in the megahertz range, and 0–30 GHz frequency tuning. This record performance was achieved using an ultralow Brillouin gain from a compact photonic chip and a novel approach of optical resonance-assisted RF signal cancellation. The results point to new ways of creating energy-efficient and reconfigurable integrated MWP signal processors for wireless communications and defence applications.

Virtual RC Damping of LCL -Filtered Voltage Source Converters With Extended Selective Harmonic Compensation

Abstract: Active damping and harmonic compensation are two common challenges faced by LCL -filtered voltage source converters. To manage them holistically, this paper begins by proposing a virtual RC damper in parallel with the passive filter capacitor. The virtual damper is actively inserted by feeding back the passive capacitor current through a high-pass filter, which indirectly, furnishes two superior features. They are the mitigation of phase lag experienced by a conventional damper and the avoidance of instability caused by the negative resistance inserted unintentionally. Moreover, with the virtual RC damper, the frequency region, within which the harmonic compensation is effective, can be extended beyond the gain crossover frequency. This is of interest to some high-performance applications, but has presently not been achieved by existing schemes. Performance of the proposed scheme has been tested in the laboratory with results obtained for demonstrating stability and harmonic compensation.

Power System Harmonics and Passive Filter Designs

Abstract: Description: Power System Harmonics provides comprehensive coverage of generation, effects, and control of harmonics, and presents its state–of–the–art technology and advancements This book is the first to cover Power System Harmonics in–depth, including real world, illustrative case studies. Written by a well–known author with extensive experience designing harmonic filters, this book is written in a thorough and easy to read way, making it an invaluable resource for practicing engineers, consultants, and academia. Coverage includes new harmonic mitigation technologies, detailed step–by–step design of passive filters, interharmonics and flicker, and more. Readers who are new to the field will be able to grasp the subject through the many examples, case studies and illustrations. More advanced readers who are already familiar with Power System Harmonics will be able to learn about new insights and the latest developments. Covers new harmonic mitigation technologies, such as advances in converter technologies for harmonic mitigation and simultaneous improvement of power factor, and detailed step–by–step design of passive filters not covered in other publications Covers comprehensive models of power system components and power systems for harmonic analysis Includes simulations of wind and solar power plants In depth coverage of the effects of harmonics Includes EMTP simulations (Electromagnetic Transients Program) for real world situations Richly illustrated; covers IEEE and IEC standards, and provides extensive references for further reading Power system harmonics, and mitigation of their deleterious effects, has become a fast–developing topic and this book will perform as a useful reference now, and in the future.

Passive Filter Design for China High-Speed Railway With Considering Harmonic Resonance and Characteristic Harmonics

Abstract: In order to make high-speed trains (HSTs) lighter and more reliable, LC or LCL high-pass filters, which are widely adopted to mitigate high-order harmonics, are not installed in most of China HSTs. Therefore, the harmonic problem is a concern, because of the significant adverse impacts it has on the tractive drive system of the train and power quality of the utility system. The harmful harmonic distortions in high-speed railways (HSRs) are mainly caused by harmonic resonance and massive characteristic harmonics emission. This paper presents the results of harmonic assessment and harmonic filter design for a typical HSR line in China. Harmonic penetration analysis (HPA) is implemented and carried out to determine the harmonic distorted types for a wide range of possible train-operating conditions in a timetable. Both statistical field test and numerical calculation are used in passive filter design for HSRs. A C-type filter is designed here to address these typical harmonic distortions. The studies will be validated by detailed simulations based on the train timetable by counting the 95% index of the 24-h profile of harmonic results.

A 3-D Printed Lightweight X-Band Waveguide Filter Based on Spherical Resonators

Abstract: A fifth order X-band waveguide bandpass filter, based on spherical resonators, has been designed, and fabricated by 3-D printing. In comparison with rectangular waveguide, spherical resonators have a higher unloaded quality factor, but at the same time suffer from closer higher order modes. In this letter, a special topology has been proposed to relieve the impact of the first three higher order modes in the resonator and ultimately to achieve a good out-of-band rejection. Stereolithography based 3-D printing is used to build the filter structure from polymer and a 25 $\mu{\rm m}$ thick copper layer is deposited to the filter. The measurement result of the filter has an excellent agreement with the simulations. The filter is also considerably lighter than a similar metal filter.

Wideband Bandpass Filter Using U-Slotted Substrate Integrated Waveguide (SIW) Cavities

Abstract: A wideband fifth-order bandpass filter (BPF) is proposed and designed using the U-slotted substrate integrated waveguide (SIW) cavities. The U-shape slots, etched on the SIW cavity, are used to form up a new multiple-mode resonator (MMR) in order to achieve a wide passband of operation while keeping the overall size of the filter circuit to be much compact. The proposed fifth-order SIW filter is 2.5 times in size reduction compared with the traditional fifth-order SIW filters using the single-mode SIW cavities. In order to prove the validity, one wideband SIW BPF on a single layer printed circuit board (PCB) is designed and experimentally examined. The measured results show that the filter achieves an insertion loss of 1.1 dB at 8.5 GHz, return loss of higher than 11 dB and 3 dB fractional bandwidth of 42%. The measured results are in good agreement with the simulated results.

Photonics to the Rescue: A Fresh Look at Microwave Photonic Filters

Abstract: Extensively researched in recent years, microwave photonic filters can be implemented either in an incoherent operational regime or in a coherent operational regime. In the incoherent regime, a delay-line configuration is usually used with a finite-impulse response (FIR) or infinite-impulse response (IIR); to avoid optical interference, an incoherence light source or a laser array is used. Filter tuning and reconfiguration are achieved by changing the time delay and the tap coefficients. In the coherent regime, however, a single wavelength is needed, and the filter?s spectral response is translated directly from the spectral response of an optical filter. Thus, a coherent microwave filter requires a well-defined optical filter with a precisely controlled spectral response. This article reviews the techniques for implementing both incoherent and coherent tunable and reconfigurable microwave photonic filters.

Approximated Fractional Order Chebyshev Lowpass Filters

Abstract: We propose the use of nonlinear least squares optimization to approximate the passband ripple characteristics of traditional Chebyshev lowpass filters with fractional order steps in the stopband. MATLAB simulations of , , and order lowpass filters with fractional steps from = 0.1 to = 0.9 are given as examples. SPICE simulations of 1.2, 1.5, and 1.8 order lowpass filters using approximated fractional order capacitors in a Tow-Thomas biquad circuit validate the implementation of these filter circuits.

A Hybrid Filter for the Suppression of Common-Mode Voltage and Differential-Mode Harmonics in Three-Phase Inverters With CPPM

Abstract: In the motor systems driven by sinusoidal pulse width modulation (SPWM) three-phase inverters, the peaks of common-mode (CM) voltage are so high that it will cause many negative effects. In this paper, a hybrid filter is presented to reduce the CM voltage (CMV) and the differential-mode (DM) harmonics in a three-phase inverter with carrier peak position modulation (CPPM). Because the use of CPPM strategy in the inverter can ensure that the output CMV will be only two levels in any condition, the simple active CM filter (composed of a half-bridge circuit) in the hybrid filter can effectively suppress the output CMV and CM current. The passive filter in the hybrid filter consists of an added single tuned filter and the original DM low-pass filter. The single tuned filter is designed to lower the DM harmonics, which are aggravated by the CPPM strategy in the carrier frequency band. Through the experiments, the validity of CMV and DM harmonics suppression by the hybrid filter in the three-phase inverter is verified and the calculation-control active CM filter is proved to be the best in the optional schemes.

A Systematic Power-Quality Assessment and Harmonic Filter Design Methodology for Variable-Frequency Drive Application in Marine Vessels

Abstract: In maritime industry, high fuel costs encourage use of variable-frequency drives (VFDs) for energy-saving applications. However, introduction of such nonlinear loads in the vessel's power distribution network induces harmonics, which can lead to potential risks if are not predicted and controlled. In this paper, a systematic power-quality assessment and monitoring methodology is proposed to calculate VFD contribution to voltage distortion at the point of common coupling (PCC), considering the source short-circuit capacity and the existing vessel's power system harmonics. According to voltage harmonic distortion limits set by marine classification societies, design and sizing of appropriate harmonic attenuation filters is made, including ac and dc chokes and frequency-tuned passive filter options. The effectiveness of the proposed power-quality analyzing procedure is evaluated through a real practical example, which includes harmonic filter design for VFD retrofit application to fan and pump motors that operate constantly during sea-going operation in a typical tanker vessel. Power-quality field measurements obtained through a harmonic monitoring platform implemented on board verify that total voltage harmonic distortion and individual voltage harmonics at PCC are maintained below 5% and 3%, respectively, showing that design complies with relevant marine harmonic standards even in the worst operating case.

Modeling and stability analysis of active/hybrid common-mode EMI filters for DC/DC power converters

Abstract: Hybrid electromagnetic interference (EMI) filters (HEFs) which are composed of an active filter and a passive filter, have been proposed to reduce the size and weight of conventional passive EMI filters. However, accurate models that can be used to predict the stability and performance of HEFs have not been developed. To cope with this, this paper presents a modeling technique for a hybrid common-mode (CM) filter. The technique can be applied to the modeling of other HEFs. Critical component models were first developed for the HEF. HEF's overall model is further developed based on these individual component models. Experimental results validated that the developed model can successfully predict the stability and performance of the hybrid CM filter.

New design of compact dual band-notch ultra-wideband bandpass filter based on coupled wave canceller inverted T-shaped stubs

Abstract: The procedure of attaining a compact bandpass filter (BPF) with dual band-notch function for ultra-wideband (UWB) applications is presented and discussed. In the proposed BPF, defected ground structure is used in order to improve the out-of-band performance of the filter. Also, four short-circuited bent stubs are employed in order to improve the selectivity of the filter at its cutoff frequencies. Dual band-notch function is added to the performance of the filter by coupling two short-circuited inverted T-shaped stubs to the filter main resonator. The fabricated filter satisfies well the demands of the Federal Communications Committee with two narrow band-notch functions at 5.5 and 8 GHz, which eliminates the interference of the UWB system with wireless local area network (WLAN) and satellite communication systems, respectively. The improved upper stop-band of the proposed filter with more than 20 dB attenuation level extends up to 20 GHz.

Implementation of Hybrid Filter for 12-Pulse Thyristor Rectifier Supplying High-Current Variable-Voltage DC Load

Abstract: This paper presents a parallel combination of a shunt-connected passive filter and a distribution static compensator (DSTATCOM) for a 12-pulse thyristor rectifier feeding a high-current variable-voltage electrolyzer load. Since the process requires variation of voltage and current over a wide range, the reactive power consumed by the thyristor rectifier also varies enormously. As the passive filter is only able to provide a fixed compensation, the DSTATCOM is used to meet variable reactive power demand to keep the input power factor high even at partial load. In order to keep the DSTATCOM rating small, the bulk of reactive power is supplied by the dominant harmonic passive filter. Moreover, DSTATCOM does not provide any harmonic compensation, which is also taken care by the passive filter. Design and control of this system are discussed briefly, and more emphasis is laid on the implementation of the hybrid filter. An experimental system is tested rigorously, and detailed results are presented.

U-Shape Slots Structure on Substrate Integrated Waveguide for 40-GHz Bandpass Filter Using LTCC Technology

Abstract: Millimeter-wave (mmW) bandpass filter using substrate integrated waveguide (SIW) is proposed in this paper The propagation constants of three different types of electromagnetic bandgap (EBG) units are discussed and compared with their passbands and stopbands performance The slotted-SIW unit shows a very good lower stopband and upper stopband performance The mmW bandpass filter with three cascaded uniform slotted-SIW-based EBG units is constructed and designed at 40 GHz The extracted coupling coefficient ( ${K}$ ) and quality factor ( ${Q}$ ) are used to determine the filter circuit dimensions To prove the validity, the previous proposed structure is fabricated in a single circuit layer using low-temperature co-fired ceramic technology and measured at 40 GHz, respectively The measured results are in good agreement with simulated results in such frequency and the measured insertion losses at 40 GHz is 142 dB, respectively

A comparative analysis of passive filters for power quality improvement

Abstract: This paper presents the design procedure of shunt passive filters for improving power quality by eliminating harmonic distortion caused by non-linear loads. The passive filters include single tuned passive filter (STPF) and double tuned passive filter (DTPF) are considered for analysis purpose. In the design of filters, the parameters of passive elements are obtained for 5th, 7th, 11th and 13th harmonic order component. The DTPF is more effective in removal of harmonic distortion while compared with STPF. The simulation of proposed system is done in the MATLAB/Simulink environment. The various results are satisfied under IEEE- 519 harmonic standard limits.

Optimal design of a single tuned passive filter to mitigate harmonics in power frequency

Abstract: Electricity has been one of the most important necessities for industrialization, increasing living standard of people around the world. Power electronic devices are applied in industry as well as in domestic appliances. The excessive use of these devices cause power quality (PQ) problems in the power system (PS), due to generation of harmonics. The consequences of harmonics include; increased probability in occurrence of resonance, neutral overload in 3-phase systems, overheating of all cables and equipment, loss of efficiency in electric machines, electromagnetic interference with communication systems, errors in measurements when using average reading meters, nuisance tripping of thermal protections. Many researches are being done to find out the best solution against the cause. For this, various tools and techniques are being improved and applied to mitigate such cause and enhance the PQ of the PS. One of the methods to mitigate harmonics is by designing and using passive filter. Moreover, it reduces the need of capacitor for supplying extra needed kVAr. Due to these two attracting features of Passive filter, its design and application can be found in many reasearches. The the main aspect of filter design has been challenging issue. This paper presents the optimal design of single tuned passive filter that its application is to mitigate harmonics in power frequency. The optimal parameters of this filter were calculated by using Lagrange interpolation method. The results were obtained by Matlab/simulation which shows the effectiveness of this filter.

A Bidirectional Control Principle of Active Tuned Hybrid Power Filter Based on the Active Reactor Using Active Techniques

Abstract: In this paper, a novel bidirectional control principle of active tuned hybrid power filter (ATHPF) based on the active reactor using active techniques is proposed. The proposed control principle, in essence, is to continuously adjust the filter inductance of the active reactor by regulating active power filter (APF) output current in terms of its magnitude and direction. Therefore, the ATHPF using the bidirectional control principle can simultaneously supply different impedances at different selective suppressed harmonic frequencies. The bidirectional control principle can perform both the normal active tuning function and the abnormal active detuning function. To be specific, the normal active tuning function refers to the harmonic elimination with filtering performance independent of the deviation of passive filter parameters, while the latter, the abnormal active detuning function, refers to the flexible protection against harmonic over-current without losing two harmonic elimination and reactive power compensation at the occurrence of harmonic over-current. Experimental results verify the effectiveness of the ATHPF with the bidirectional control principle in selective harmonic elimination and flexible protection against harmonic over-current.

Reconfigurable fully differential first order all pass filter using digitally controlled CMOS DVCC

Abstract: The paper presents a reconfigurable fully differential all pass filter based on CMOS differential voltage current conveyor. The proposed topology uses two differential voltage current conveyors along with two resistors and two capacitors. The phase angle of the realized fully differential all pass filter can be controlled through an n-bit digital control word. Thus the proposed filter topology provides increased immunity to external noise, reduced even-order harmonics, high resolution capability and reconfigurability. The proposed filter circuit is simulated by using PSPICE. The results thus obtained justify the theory.

Novel VDCC based low-pass and high-pass Ladder filters

Abstract: This paper presents 5th order Low-Pass (LP) and High-Pass (HP) Ladder filters employing two Voltage Differencing Current Conveyors (VDCCs), four resistors and five capacitors The workability of the proposed circuits has been tested using SPICE simulations

Third-order voltage-mode active-C band pass filter

Abstract: In this research article, a new third-order voltage-mode active-C asymmetrical band pass filter is proposed. It uses three numbers of current-controlled current conveyors and three numbers of equal-valued capacitors. The topology has the following important features: uses only three active elements, uses three capacitors, uses all grounded capacitors and no resistor is suitable for integrated circuit design, there is no matching constraint, high input impedance, low output impedance, central frequency can easily be electronically controlled by bias current, and frequency response is asymmetrical in nature. The application of the proposed topology in the realisation of a voltage-mode sixth-order symmetrical band pass filter has been demonstrated. The workability of the proposed topology and sixth-order filter has been confirmed by simulation results using 0.35-µm Austria Micro Systems complementary metal oxide semiconductor technology.

Multi-mega VAR passive filters for mining applications: Practical limitations and technical considerations

Abstract: This paper analyzes and proposes technical considerations for the selection and design of passive filter schemes rated at several mega-vars to compensate reactive power and current harmonics in mining power distribution systems. The paper includes technical information and analysis required to select the most adequate passive filter topology, to select the tuning frequency for each unit, to calculate filter parameters, and to distribute reactive power between passive filters. Passive filter schemes analyzed in this paper are used to compensate mining power distribution systems, especially when high power grinding mill drives energized from 12-pulse cycloconverters are used in conjunction with several other nonlinear loads. The manuscript also analyzes technical limitations that passive filters present in the attenuation of low frequency current harmonics. Finally, two power distribution systems with different passive filters schemes are evaluated, and the limitations in the attenuation of low frequency current harmonics generated by cycloconverters are demonstrated with measured results.

Grid connected CM noise considerations of a three-phase multi-stage SST

Abstract: Solid State Transformer (SST) is an alternative to the conventional distribution transformer for smart grid applications. By employing a compact Medium-Frequency (MF) transformer for isolation, the SST has merits on size and weight. It also provides flexible utilization as a FACTS component. The switching converters are a potential source of Common-Mode (CM) and HF EMI noises. These noises are more nuisance in a SiC device based SST which switches at a high dV/dT at the Medium-Voltage (MV) level resulting in high CM voltages. The SST floating metalic surfaces such as heatsink and the output must be grounded for safety and smooth operation. However there are various significant low impedance paths present, including the parasitics of the compact transformer, which may conduct CM noise to the grid. The generated CM noise may affect the controls. This paper presents the CM and grounding challenges in the multistage integration of a three-phase SST system based on 15kV SiC IGBTs termed as Transformerless Intelligent Power Substation (TIPS). The TIPS interfaces MV 13.8kV and LV 480V grids using MV ac-dc, MV to LV dc-dc dual active bridge and LV dc-ac inverter stages. A study on the CM noise in the TIPS and a passive filter solution for its attenuation is presented in this paper. A time domain simulation considering the passive filter specification is also presented. The experimental results for line to line 3.64kV MV grid integration are presented. A LV prototype is used to verify the complete grounding and the CM choke design at a scaled-down condition.

Research and realization of a novel active common-mode EMI filter

Abstract: Voltages and currents of high power density power electronic circuits vary rapidly for its high speed switching, which results in serious electromagnetic interference (EMI) problems. The conventional used EMI filters are made of passive inductors and capacitors. Its size is usually comparable to that of the converter itself. As to this, active EMI filters (AEF) made of amplifiers and transistors are proposed. In this paper, a novel AEF topology used for DC-DC power converters is proposed. The most distinguished feature of this filter is that it shares the same power supply with the DC-DC converter. Thus, the size and weight of the whole filter is reduced to a great extent. The experimental results show that the proposed filter worked well and could attenuate the noise with high effectiveness.

Design, Application and Comparison of Passive Filters for Three-Phase Grid-Connected Renewable Energy Systems

Abstract: Second and third-order passive filters (LC and LCL) are interesting filters to use for grid-connected PWM inverters. Because of the stability problems of these filters around resonance frequency, series and damping resistor can be add to an LCL filter. However, the resistor value has impact on the filter respond, voltage and current harmonic distortion and filter power loss. In this paper, the mathematic characteristics of LC, LCL filter, series and parallel damping LCL filters will be described with their design to apply in 3-phase PV grid-connected inverter. And, simulations have down to validate the theoretical analysis of the filters on filter performance, power quality and filter power loss for 3-phase grid-connected renewable energy system application.

Lamb Wave AlN Micromechanical Filters Integrated With On-chip Capacitors for RF Front-End Architectures

Abstract: This paper reports on the implementation of an ultraminiature 140 MHz narrowband filter based on aluminum nitride Lamb wave resonators. Monolithically integrated with a pair of on-chip capacitors and cascaded with a pair of inductors, the filter is well matched to 50 ohm, showing a remarkably high performance. A low pass-band insertion loss of 2.78 dB and steep filter skirts are achieved. The form factor of the monolithic microelectromechanical systems filter is more than ten times smaller than its surface acoustic wave counterpart in the intermediate frequency band and it involves much simpler matching circuits.