Hybrid Filter

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Hirofumi Akagi - One of the best experts on this subject based on the ideXlab platform.

  • Design and Performance of a Transformerless Shunt Hybrid Filter Integrated Into a Three-Phase Diode Rectifier
    IEEE Transactions on Power Electronics, 2007
    Co-Authors: Wiroj Tangtheerajaroonwong, T. Hatada, Keiji Wada, Hirofumi Akagi
    Abstract:

    This paper addresses a transformerless shunt Hybrid Filter integrated into a three-phase diode rectifier. The Hybrid Filter consists of a three-phase passive Filter tuned to the seventh-harmonic frequency, and a small-rated active Filter based on a three-phase voltage-source pulsewidth modulation converter. The validity of the system design is confirmed by experimental results obtained from a 400-V, 15-kW laboratory system. The experimental results show that the active Filter plays an essential role in reducing supply harmonic currents. The total harmonic distortion of the supply current gets less than 5%. Moreover, the Hybrid Filter provides satisfactory transient performance as a result of having achieved an optimal design of circuit and control parameters including the dc capacitor voltage and feedback gains of the active Filter, along with the cutoff frequency of high-pass Filters for harmonic extraction.

  • a 6 6 kv transformerless shunt Hybrid active Filter for installation on a power distribution system
    IEEE Transactions on Power Electronics, 2005
    Co-Authors: R Inzunza, Hirofumi Akagi
    Abstract:

    This paper presents a fully-digital-controlled shunt Hybrid Filter for damping of harmonic propagation in power distribution systems. The harmonic propagation is caused by resonance between line inductances and power capacitors installed for power factor correction. A possible solution to damping out harmonic propagation is based on installation of a shunt pure active Filter at the end of a feeder. This paper proposes a shunt Hybrid active Filter characterized by series connection of a seventh-tuned LC Filter per phase and a small-rated three-phase active Filter. Like the pure Filter, the Hybrid Filter is connected to the end bus of a feeder. The capacitor of the LC Filter imposes a high impedance to the fundamental frequency, so that the fundamental voltage appears across the capacitor. This unique feature allows us to directly connect the Hybrid Filter to the 6.6-kV power line without step-down transformers. Furthermore, the capacitor used in this Hybrid Filter is lighter, cheaper and smaller than the transformer used in the pure Filter. Theoretical analysis, along with experimental results obtained from a 200-V, 20-kW laboratory system, verifies the viability and effectiveness of the proposed Hybrid Filter.

  • a 6 6 kv transformerless shunt Hybrid active Filter for installation on a power distribution system
    Power Electronics Specialists Conference, 2004
    Co-Authors: R Inzunza, Hirofumi Akagi
    Abstract:

    This paper presents a fully-digital-controlled shunt Hybrid Filter for damping of harmonic propagation in power distribution systems. The harmonic propagation is caused by resonance between line inductances and power capacitors installed for power factor correction. A possible solution to damping out harmonic propagation is based on installation of a shunt pure active Filter at the end of a feeder This paper proposes a shunt Hybrid active Filter characterized by series connection of a 7th tuned LC Filter per phase and a small-rated three-phase active Filter. Like the pure Filter, the Hybrid Filter is connected to the end bus of a feeder. The capacitor of the LC Filter imposes a high impedance to the fundamental frequency, so that the fundamental voltage appears across the capacitor. This unique feature allows us to directly connect the Hybrid Filter to the 6.6 kV power line without step-down transformers. Furthermore, the capacitor used in this Hybrid Filter is lighter, cheaper and smaller than the transformer used in the pure Filter. Theoretical analysis, along with experimental results obtained from a 200-V, 20-kW laboratory system, verifies the viability and effectiveness of the proposed Hybrid Filter.

  • a medium voltage transformerless ac dc power conversion system consisting of a diode rectifier and a shunt Hybrid Filter
    IEEE Industry Applications Society Annual Meeting, 2002
    Co-Authors: S Srianthumrong, Hirofumi Akagi
    Abstract:

    This paper proposes a 3.3-kV transformerless AC-to-DC power conversion system consisting of a three-phase six-pulse diode rectifier and a shunt Hybrid Filter. The Hybrid Filter is formed by a single tuned LC Filter per phase and a small-rated three-phase active Filter, which are directly connected in series without any matching transformer. The required rating of the active Filter is much smaller than that of a conventional standalone active Filter be. In addition, no additional switching-ripple Filter is required for the Hybrid Filter because the LC Filter functions not only as a harmonic Filter tuned at the seventh harmonic frequency but also as a switching-ripple Filter around 10 kHz. Experimental results obtained from a 200-V 5-kW laboratory system and simulation results of a 3.3-kV 300-kW system confirm the validity and effectiveness of the system.

  • Design of a Transformerless Shunt Hybrid Filter Integrated into a Three-Phase Diode Rectifier
    37th IEEE Power Electronics Specialists Conference, 1
    Co-Authors: Wiroj Tangtheerajaroonwong, T. Hatada, Keiji Wada, Hirofumi Akagi
    Abstract:

    This paper describes design and performance of a transformerless shunt Hybrid Filter integrated into a three-phase diode rectifier. The Hybrid Filter consists of a three-phase passive Filter tuned to the 7th-harmonic frequency, and a small-rated active Filter based on a three-phase voltage-source PWM converter. The validity of the system design is confirmed by experimental results obtained from a 400-V, 15-kW laboratory system. The experimental results show that the active Filter plays an essential role in reducing supply harmonic currents. The THD (total harmonic distortion) of the supply current gets less than 5%. Moreover, the Hybrid Filter provides satisfactory transient performance as a result of having achieved an optimal design of circuit and control parameters including the dc capacitor voltage and feedback gains of the active Filter, along with the cut-off frequency of high-pass Filters for harmonic extraction.

Jacques Oksman - One of the best experts on this subject based on the ideXlab platform.

  • Wide-band, band-pass and versatile Hybrid Filter Bank A/D conversion for software radio
    IEEE Circuits and Systems Magazine, 2009
    Co-Authors: Caroline Lelandais-perrault, Daniel Poulton, Pierre Duhamel, Tudor Petrescu, Jacques Oksman
    Abstract:

    This paper deals with analog-to-digital (A/D) conversion for future software/cognitive radio systems. For these applications, A/D converters should convert wideband signals and offer high resolutions. In order to achieve this and to overcome technological limitations, the A/D conversion systems should be versatile, i.e. it should be possible to adapt the conversion characteristics (resolution and bandwidth) by software. This work studies and adapts Hybrid Filter Banks (HFBs) in this context. First, HFBs, which can provide large conversion bandwidth, are extended to band-pass sampling, thus minimizing the sampling frequency. Then, we provide efficient ways of improving the HFB resolution in a smaller frequency band, only by reprogramming the digital part. Moreover, this study takes into account the main drawback of HFBs which is their very high sensitivity to analog imperfections. Simulation results are presented to demonstrate the performance of HFBs.

  • Subband architecture for Hybrid Filter Bank A/D converters
    IEEE Journal of Selected Topics in Signal Processing, 2008
    Co-Authors: Davud Asemani, Jacques Oksman, Pierre Duhamel
    Abstract:

    Abstract—Hybrid Filter Bank (HFB) A/D converters (ADC) are a candidate to realize the wide-band ADC for future telecommunication systems. The classical HFB-based ADCs are simulated in both time and frequency domains using simplyrealizable analog Filters in this paper. The high sensitivity of HFB to realization errors of analysis Filter bank is studied and it is shown that a new HFB architecture is necessary to employ the blind techniques for correcting the analog imperfections. Using the discrete-time model of HFB, a Multiple-Input Multiple-Output (MIMO) model is proposed for the HFB so that a new architecture called subband HFB-based ADC is obtained. The subband HFB ADC not only leads to a better resolution but is less sensitive to realization errors than the classical case. Besides, a Linear-Time Invariant (LTI) system represents the input-output relation of subband HFB without any spectral overlapping in contrary to the classical HFB. Thus, blind techniques may be used for correcting the realization errors in the subband HFB.

  • Time-Division Multiplexing Architecture for Hybrid Filter Bank A/D converters
    2007
    Co-Authors: Davud Asemani, Jacques Oksman
    Abstract:

    In this paper, a new Hybrid Filter Bank (HFB) architecture called Time-Division Multiplexing (TDM) is proposed for HFB-based A/D Converters (ADC). The TDM HFB architecture is firstly extracted considering the TDM components of analog input as new input vector. The TDM HFB-based ADC is then simulated using simply-realizable analysis Filters to approve the mathematical formulation of the TDM model. At last, the output resolutions of TDM and classical HFB-based ADC are compared considering practical analog Filters including realization errors. It is shown that the TDM architecture is less sensitive to the realization errors than the classical HFB. Besides, the TDM HFB can exploit a blind technique to correct the realization errors in opposite to the classical HFB case.

  • Influences of oversampling and analog imperfections on Hybrid Filter Bank A/D converters
    2006
    Co-Authors: Davud Asemani, Jacques Oksman
    Abstract:

    Hybrid Filter Banks (HFB) are considered as good candidate for implementing wide-band, high-frequency A/D parallel converters. The performance of HFB (original and twostage) structures is analyzed for different values of oversampling ratios leading to the choice of the optimal value. The electronic elements of the analysis Filter bank of HFB structure are considered with real constraints (realization errors and drifts). Real analysis Filters of HFB are considered with the analog elements for which the real values are randomly Gaussian-distributed. Sensitivity to the deviations from real values is simulated and the performance of two HFB (original and two-stage) structures are compared. The possible methods for decreasing the sensitivity to realization errors such as Total Least Squares (TLS) optimization are discussed. Original structure is found to be a better candidate rather than the two-stage one in practical cases. However, it is shown that a blind estimation method would be necessary to compensate the realization errors for practically implementing the HFB-based A/D converters.

  • sensitivity of Hybrid Filter banks a d converters to analog realization errors and finite word length
    International Conference on Acoustics Speech and Signal Processing, 2006
    Co-Authors: Teodor Petrescu, Jacques Oksman
    Abstract:

    This paper studies the sensitivity of Hybrid Filter banks (HFB) to analog inaccuracies and finite word implementation. It is shown that very small errors affecting very simple analog structures have a dramatic influence on the performances of the HFB. The influence of the quantization of digital Filter coefficients is also studied. A theoretical limit for the error introduced by the quantization of digital Filter coefficients is derived.

Pierre Duhamel - One of the best experts on this subject based on the ideXlab platform.

  • Wide-band, band-pass and versatile Hybrid Filter Bank A/D conversion for software radio
    IEEE Circuits and Systems Magazine, 2009
    Co-Authors: Caroline Lelandais-perrault, Daniel Poulton, Pierre Duhamel, Tudor Petrescu, Jacques Oksman
    Abstract:

    This paper deals with analog-to-digital (A/D) conversion for future software/cognitive radio systems. For these applications, A/D converters should convert wideband signals and offer high resolutions. In order to achieve this and to overcome technological limitations, the A/D conversion systems should be versatile, i.e. it should be possible to adapt the conversion characteristics (resolution and bandwidth) by software. This work studies and adapts Hybrid Filter Banks (HFBs) in this context. First, HFBs, which can provide large conversion bandwidth, are extended to band-pass sampling, thus minimizing the sampling frequency. Then, we provide efficient ways of improving the HFB resolution in a smaller frequency band, only by reprogramming the digital part. Moreover, this study takes into account the main drawback of HFBs which is their very high sensitivity to analog imperfections. Simulation results are presented to demonstrate the performance of HFBs.

  • wideband bandpass and versatile Hybrid Filter bank a d conversion for software radio
    Custom Integrated Circuits Conference, 2009
    Co-Authors: Caroline Lelandaisperrault, Teodor Petrescu, Pierre Duhamel, D Poulton, J Oksman
    Abstract:

    This paper deals with analog-to-digital (A/D) conversion for future software/cognitive radio systems. For these applications, A/D converters should convert wideband signals and offer high resolutions. In order to achieve this and to overcome technological limitations, the A/D conversion systems should be versatile, i.e., it should be possible to adapt the conversion characteristics (resolution and bandwidth) by software. This work studies and adapts Hybrid Filter banks (HFBs) in this context. First, HFBs, which can provide a large conversion bandwidth, are extended to bandpass sampling, thus minimizing the sampling frequency. Then, we provide efficient ways of improving the HFB resolution in a smaller frequency band, only by reprogramming the digital part. Moreover, this paper takes into account the main drawback of HFBs which is their very high sensitivity to analog imperfections. Simulation results are presented to demonstrate the performance of HFBs.

  • Subband architecture for Hybrid Filter Bank A/D converters
    IEEE Journal of Selected Topics in Signal Processing, 2008
    Co-Authors: Davud Asemani, Jacques Oksman, Pierre Duhamel
    Abstract:

    Abstract—Hybrid Filter Bank (HFB) A/D converters (ADC) are a candidate to realize the wide-band ADC for future telecommunication systems. The classical HFB-based ADCs are simulated in both time and frequency domains using simplyrealizable analog Filters in this paper. The high sensitivity of HFB to realization errors of analysis Filter bank is studied and it is shown that a new HFB architecture is necessary to employ the blind techniques for correcting the analog imperfections. Using the discrete-time model of HFB, a Multiple-Input Multiple-Output (MIMO) model is proposed for the HFB so that a new architecture called subband HFB-based ADC is obtained. The subband HFB ADC not only leads to a better resolution but is less sensitive to realization errors than the classical case. Besides, a Linear-Time Invariant (LTI) system represents the input-output relation of subband HFB without any spectral overlapping in contrary to the classical HFB. Thus, blind techniques may be used for correcting the realization errors in the subband HFB.

Caroline Lelandais-perrault - One of the best experts on this subject based on the ideXlab platform.

Daniel Poulton - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis of Subband Hybrid Filter Banks ADCs with Finite Word-length Coefficients using Adaptive Equalization
    2010
    Co-Authors: Zhiguo Song, Daniel Poulton, Caroline Lelandais-perrault, Philippe Benabes
    Abstract:

    Subband Hybrid Filter Banks (SHFB) ADCs are able to convert one or several narrow subbands among a given wideband signal. That provides an appropriate solution to "flexible spectrum" management for cognitive radio applications. In this paper, a SHFB ADC delivering a complex signal is considered. The optimal values of the digital coecients are obtained thanks to an adaptive equalization method. The impact of digital coecients quantization to the SHFB is studied. For a reconstruction quality target, the minimum quantization step is determined. This is validated in time and frequency domain with simulation results.

  • Adaptive Equalization for Calibration of Subband Hybrid Filter Banks A/D Converters
    2009
    Co-Authors: Zhiguo Song, Daniel Poulton, Caroline Lelandais-perrault, Philippe Benabes
    Abstract:

    Hybrid Filter Banks (HFB) A/D converters (ADC) are attractive to software-defined radio application, however their high sensitivity to analog imperfections is still a bottleneck for their realization. In this paper, adaptive equalization is applied for calibrating a subband HFB ADC. Thus, the synthesis Filter coefficients are iteratively adjusted for compensating the mis-matches between the analog part and the digital part. Simulations show that the robustness of subband HFB ADC is therefore improved.

  • Wide-band, band-pass and versatile Hybrid Filter Bank A/D conversion for software radio
    IEEE Circuits and Systems Magazine, 2009
    Co-Authors: Caroline Lelandais-perrault, Daniel Poulton, Pierre Duhamel, Tudor Petrescu, Jacques Oksman
    Abstract:

    This paper deals with analog-to-digital (A/D) conversion for future software/cognitive radio systems. For these applications, A/D converters should convert wideband signals and offer high resolutions. In order to achieve this and to overcome technological limitations, the A/D conversion systems should be versatile, i.e. it should be possible to adapt the conversion characteristics (resolution and bandwidth) by software. This work studies and adapts Hybrid Filter Banks (HFBs) in this context. First, HFBs, which can provide large conversion bandwidth, are extended to band-pass sampling, thus minimizing the sampling frequency. Then, we provide efficient ways of improving the HFB resolution in a smaller frequency band, only by reprogramming the digital part. Moreover, this study takes into account the main drawback of HFBs which is their very high sensitivity to analog imperfections. Simulation results are presented to demonstrate the performance of HFBs.

  • Hybrid Filter Bank A/D conversion systems applied to future telecommunication scenarios
    2009
    Co-Authors: Caroline Lelandais-perrault, Zhiguo Song, Daniel Poulton
    Abstract:

    Hybrid Filter Banks (HFB) A/D converters (ADC) are attractive to software-defined radio applications. Starting from a given sampling rate, they enlarge the conversion band-width. Also, it is possible to adapt the conversion characteristics (e.g. bandwidth and resolution) by software control. HFB have been studied in the context of the ANR VersaNum project. This work proposes optimal HFBs and a calibration technique to compensate the mismatch between the analog part and the digital part. Results are given for future telecommunication scenarios.

  • Anti-aliasing Filter in Hybrid Filter Banks
    2006
    Co-Authors: Daniel Poulton
    Abstract:

    Hybrid Filter Banks allow wide-band, high frequency conversion. All existing design methods suppose that the input signal is band-limited and that each sub-band signal is sampled at 1/M times the effective Nyquist frequency of the input signal 1/T . To avoid aliasing in the sampling process, an analog anti-aliasing Filter should be used in order to eliminate noise in frequency bands in which there is no signal (or a few signal) . In this paper, it is shown that this pre-Filtering operation is critical and has to be done taking into account the respective power spectral densities of signal and noise due to the spectral aliasing with the sampling rate compressor. Results will be demonstrated for the design of a realistic 8 channel Hybrid Filter Bank.

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