The Experts below are selected from a list of 37464 Experts worldwide ranked by ideXlab platform

Boonteck Ooi - One of the best experts on this subject based on the ideXlab platform.

  • feasibility of both vector control and Displacement Factor correction by voltage source type ac ac matrix converter
    IEEE Transactions on Industrial Electronics, 1995
    Co-Authors: M Kazerani, Boonteck Ooi
    Abstract:

    This paper shows that by transforming both sides of the matrix converter to the d-q-o frames of their respective frequencies, there is significant simplification in the transformation matrix which enables the network of one side to be integrated to the other. Thus, it is possible to design for operation with field vector control on the motor side and unity Displacement Factor on the supply side. Laboratory experimental and digital simulation results are presented to substantiate the theory. The matrix converter used in the test is based on three modules of voltage-source SPWM converters to implement the nine switches and it has the innovative feature that the SVC voltages (for Displacement Factor improvement) can be derived from the zero-sequence voltages. >

  • application of dyadic matrix converter theory in conceptual design of dual field vector and Displacement Factor controls
    IEEE Industry Applications Society Annual Meeting, 1994
    Co-Authors: Boonteck Ooi, M Kazerani
    Abstract:

    This paper shows that the direct AC-AC matrix power converter can simultaneously implement field vector control on the variable speed AC motor side and Displacement Factor correction on the supply side. The conceptual design demonstrates that there are sufficient independent levers in the existence matrix of the direct matrix power converter for feedback loops to be implemented. The analytical conclusion is confirmed by detailed digital simulations, showing feedback convergence to reference set points. The results of an open loop experiment are presented as proof for the correctness of the analytical study. The conceptual design is based on the development and application of the dyadic matrix power converter theory. >

  • feasibility of both vector control and Displacement Factor correction by voltage source type ac ac matrix converter
    Conference of the Industrial Electronics Society, 1994
    Co-Authors: M Kazerani, Boonteck Ooi
    Abstract:

    This paper shows that by transforming both sides of the matrix power converter to the d-q-o frames of their respective frequencies, there is significant simplification in the existence matrix which enables the network of one side to be integrated to the other. Thus, it is possible to design for operation with field vector control on the motor side and unity Displacement Factor on the supply side. Laboratory experimental and digital simulation results are presented to substantiate the theory. The matrix power converter used in the test is based on three modules of voltage-source SPWM power converters to implement the 9 switches and it has the innovative feature that the SVC voltages (for Displacement Factor improvement) can be derived from the zero-sequence voltages. >

Suzanne R Pfeffer - One of the best experts on this subject based on the ideXlab platform.

  • purification and properties of yip3 pra1 as a rab gdi Displacement Factor
    Methods in Enzymology, 2005
    Co-Authors: Ulf Sivars, Dikran Aivazian, Suzanne R Pfeffer
    Abstract:

    Prenylated Rab proteins exist in the cytosol bound to guanine dissociation inhibitor (GDI). These dimeric complexes contain all of the information needed for accurate membrane delivery. We have shown that membranes contain a proteinaceous activity that is required for Rab delivery, and we named that activity GDI Displacement Factor (GDF). Biochemical analysis revealed that GDF activity was membrane associated and had a mass of approximately 25 kDa. We therefore used a candidate gene approach and were able to show that pure Yip3/PRA1 protein displays GDF activity. In this chapter, we review key aspects of GDF analysis: our assay and the method by which we purify Yip3/PRA1 in active form.

  • identification of a gdi Displacement Factor that releases endosomal rab gtpases from rab gdi
    The EMBO Journal, 1997
    Co-Authors: Barbara A Diracsvejstrup, Tomoyuki Sumizawa, Suzanne R Pfeffer
    Abstract:

    Prenylated Rab GTPases occur in the cytosol in their GDP‐bound conformations bound to a cytosolic protein termed GDP‐dissociation inhibitor (GDI). Rab–GDI complexes represent a pool of active, recycling Rab proteins that can deliver Rabs to specific and distinct membrane‐bound compartments. Rab delivery to cellular membranes involves release of GDI, and the membrane‐associated Rab protein then exchanges its bound GDP for GTP. We report here the identification of a novel, membrane‐associated protein Factor that can release prenylated Rab proteins from GDI. This GDI‐Displacement Factor (GDF) is not a guanine nucleotide exchange Factor because it did not influence the intrinsic rates of nucleotide exchange by Rabs 5, 7 or 9. Rather, GDF caused the release of each of these endosomal Rabs from GDI, permitting them to exchange nucleotide at their intrinsic rates. GDF displayed the greatest catalytic rate enhancement on Rab9–GDI complexes. However, catalytic rate enhancement paralleled the potency of GDI in blocking nucleotide exchange: GDI was shown to be most potent in blocking nucleotide exchange by Rab9. The failure of GDF to act on Rab1–GDI complexes suggests that it may be specific for endosomal Rab proteins. This novel, membrane‐associated activity may be part of the machinery used to localize Rabs to their correct intracellular compartments.

M Kazerani - One of the best experts on this subject based on the ideXlab platform.

  • feasibility of both vector control and Displacement Factor correction by voltage source type ac ac matrix converter
    IEEE Transactions on Industrial Electronics, 1995
    Co-Authors: M Kazerani, Boonteck Ooi
    Abstract:

    This paper shows that by transforming both sides of the matrix converter to the d-q-o frames of their respective frequencies, there is significant simplification in the transformation matrix which enables the network of one side to be integrated to the other. Thus, it is possible to design for operation with field vector control on the motor side and unity Displacement Factor on the supply side. Laboratory experimental and digital simulation results are presented to substantiate the theory. The matrix converter used in the test is based on three modules of voltage-source SPWM converters to implement the nine switches and it has the innovative feature that the SVC voltages (for Displacement Factor improvement) can be derived from the zero-sequence voltages. >

  • application of dyadic matrix converter theory in conceptual design of dual field vector and Displacement Factor controls
    IEEE Industry Applications Society Annual Meeting, 1994
    Co-Authors: Boonteck Ooi, M Kazerani
    Abstract:

    This paper shows that the direct AC-AC matrix power converter can simultaneously implement field vector control on the variable speed AC motor side and Displacement Factor correction on the supply side. The conceptual design demonstrates that there are sufficient independent levers in the existence matrix of the direct matrix power converter for feedback loops to be implemented. The analytical conclusion is confirmed by detailed digital simulations, showing feedback convergence to reference set points. The results of an open loop experiment are presented as proof for the correctness of the analytical study. The conceptual design is based on the development and application of the dyadic matrix power converter theory. >

  • feasibility of both vector control and Displacement Factor correction by voltage source type ac ac matrix converter
    Conference of the Industrial Electronics Society, 1994
    Co-Authors: M Kazerani, Boonteck Ooi
    Abstract:

    This paper shows that by transforming both sides of the matrix power converter to the d-q-o frames of their respective frequencies, there is significant simplification in the existence matrix which enables the network of one side to be integrated to the other. Thus, it is possible to design for operation with field vector control on the motor side and unity Displacement Factor on the supply side. Laboratory experimental and digital simulation results are presented to substantiate the theory. The matrix power converter used in the test is based on three modules of voltage-source SPWM power converters to implement the 9 switches and it has the innovative feature that the SVC voltages (for Displacement Factor improvement) can be derived from the zero-sequence voltages. >

A K Chattopadhyay - One of the best experts on this subject based on the ideXlab platform.

  • observer based stator flux oriented vector control of cycloconverter fed synchronous motor drive
    IEEE Transactions on Industry Applications, 1997
    Co-Authors: A K Chattopadhyay
    Abstract:

    A six-pulse noncirculating-current cycloconverter-fed synchronous motor with stator-flux-oriented vector control for high-power and low-speed applications is discussed here. Vector control is achieved by stator flux estimation through a novel closed-loop reduced-order observer exhibiting stable speed regulation. Variable Displacement Factor operation is incorporated to keep both the system current continuous and the system utilization optimum. A simple method is used in designing the controller for armature current regulation with good performance. A generalized digital simulation of the drive system is made, and the simulation results are validated by a low-cost laboratory implementation of the drive with a 386DX PC-based system with 80387 floating point support.

  • observer based stator flux oriented vector control of cycloconverter fed synchronous motor drive
    IEEE International Conference on Power Electronics Drives and Energy Systems, 1996
    Co-Authors: A K Chattopadhyay
    Abstract:

    A 6-pulse noncirculating current cycloconverter-fed synchronous motor with stator flux oriented vector control for high power and low speed applications is discussed here. Vector control is achieved by stator flux estimation through a novel closed loop reduced order observer robust to speed variation. Variable Displacement Factor operation is incorporated to keep both the system current continuous and system utilisation optimum. A simple method is used for armature current regulation with good performance. A generalized digital simulation of the drive system is made and the simulation results are validated by a practical implementation of the drive with a 386DX-387 based system.

Ahmed Elserougi - One of the best experts on this subject based on the ideXlab platform.

  • An interline dynamic voltage restoring and Displacement Factor controlling device (IVDFC)
    IEEE Transactions on Power Electronics, 2014
    Co-Authors: Ahmed Elserougi, Ayman S. Abdel-khalik, Shehab Ahmed, Ahmed M. Massoud, Ahmed Abdalla Hossam-eldin
    Abstract:

    An interline dynamic voltage restorer (IDVR) is invariably employed in distribution systems to mitigate voltage sag/swell problems. An IDVR merely consists of several dynamic voltage restorers (DVRs) sharing a common dc link connecting independent feeders to secure electric power to critical loads. While one of the DVRs compensates for the local voltage sag in its feeder, the other DVRs replenish the common dc-link voltage. For normal voltage levels, the DVRs should be bypassed. Instead of bypassing the DVRs in normal conditions, this paper proposes operating the DVRs, if needed, to improve the Displacement Factor (DF) of one of the involved feeders. DF improvement can be achieved via active and reactive power exchange (PQ sharing) between different feeders. To successfully apply this concept, several constraints are addressed throughout the paper. Simulation and experimental results elucidate and substantiate the proposed concept.

  • Active and reactive power management of photovoltaic-based interline dynamic voltage restorer in low voltage distribution networks
    2012 IEEE Energy Conversion Congress and Exposition (ECCE), 2012
    Co-Authors: Ahmed Elserougi, Ayman S. Abdel-khalik, S. Ahmed, A. Massoud
    Abstract:

    A dynamic voltage restorer (DVR) is a series connected device that can support the voltage at existing critical loads during voltage sags. Voltage restoration may need active and/or reactive power injection into the distribution feeder. Due to the limitation of the DVR energy storage element, the Interline Dynamic Voltage Restorer (IDVR) can be used to mitigate the voltage sag in distribution systems. In a two-line IDVR system, the active power required for voltage restoration is obtained from the neighboring feeder. The maximum active power that can be injected by the neighboring feeder depends on its load Displacement Factor. Renewable energy sources and batteries can be connected across the common DC link to share the required active power in case of insufficient mitigation of the voltage sag by the neighboring feeder or both feeders are experiencing simultaneous voltage sag. This paper focuses on active and reactive power management of a photovoltaic-based (PV-based) IDVR for supporting the system during voltage sags to enhance the system reliability and power quality. A complete strategy with operational constraints for a two-line PV-based IDVR in low voltage distribution networks is proposed in this paper. Simulation and practical results are presented to substantiate the proposed concept.