The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform

Andrea Pascucci - One of the best experts on this subject based on the ideXlab platform.

Marco Di Francesco - One of the best experts on this subject based on the ideXlab platform.

J A Ferreira - One of the best experts on this subject based on the ideXlab platform.

  • detailed derivation and minimization of the equivalent parasitic capacitances of a high voltage multiplier based on the Complete Model
    IEEE Transactions on Industry Applications, 2015
    Co-Authors: Jianing Wang, Sjoerd W H De Haan, J A Ferreira
    Abstract:

    The authors' previous paper presents the Complete Model of parasitic capacitances in a high-voltage (HV) multiplier in the HV generator in a medical X-ray machine. The equivalent parasitic capacitance of the multiplier $C_{\rm em}$ based on the Model is exhibited to interpret the role of the parasitic capacitances in circuit operation of the generator. Without derivation of the analytical expression of $C_{\rm em}$ , its dependence on the component parameters is directly shown, which leads to guidelines for minimization of $C_{\rm em}$ . However, the Complete capacitance Model has a complicated structure and contains voltage-dependent capacitances and voltage sources, which gives complexity to derivation of $C_{\rm em}$ as well as difficulties to clear understanding of the voltage dependence of $C_{\rm em}$ . Thus, this paper presents the detailed derivation and analytical expression of $C_{\rm em}$ . Exactly speaking, the key part of $C_{\rm em}$ , namely, the total chain capacitance $C_{\rm Dcht}$ that determines the voltage dependence of $C_{\rm em}$ , is conducted. A simple way is presented for the derivation of $C_{\rm Dcht}$ . The derivation enables a clear understanding of the voltage dependence of $C_{\rm Dcht}$ . Moreover, a design procedure for minimization of $C_{\rm em}$ is created, accompanied by a case study. It gives designers step-by-step rules to make an optimal HV multiplier with a minimum $C_{\rm em}$ .

  • Detailed derivation and minimization of the equivalent parasitic capacitance of a high voltage multiplier based on the Complete Model
    2013 IEEE Energy Conversion Congress and Exposition, 2013
    Co-Authors: Jianing Wang, Sjoerd W H De Haan, J A Ferreira
    Abstract:

    This is a follow-up paper to the publication [1]. The previous paper presents the Complete Model of parasitic capacitances of a high voltage (HV) multiplier, which is employed as a capacitive rectifier in HV generator in medical x-ray machine. The equivalent parasitic capacitance of the multiplier Cem based on the Model is exhibited to interpret the role of the parasitic capacitances in circuit operation of the HV generator. Without detailed explanation about derivation of analytical expression of Cem, its dependence on the component parameters are directly shown, which leads to guidelines for minimization of Cem. However, the Complete Model shows a capacitance network with complicated structure and containing voltage-dependent capacitances and constant voltage sources, which gives complexity to derivation of Cem as well as difficulties to clear understanding of the voltage dependence of Cem. Thus, this paper presents the detailed derivation and analytical expression of Cem. Exactly speaking, the key part of Cem, namely the total chain capacitance CDcht that determines the voltage dependence of Cem, is conducted. A simple way is presented for the derivation of CDcht. The derivation can give readers a clear understanding of the voltage dependence of CDcht. Besides the derivation, a design procedure for minimization of Cem is created based on the proposed guidelines in [1], accompanied by a case study. It gives designers step-by-step rules to make an optimal HV multiplier with a minimum Cem.

  • Complete Model of parasitic capacitances in a cascade voltage multiplier in the high voltage generator
    2013 IEEE ECCE Asia Downunder, 2013
    Co-Authors: Jianing Wang, Sjoerd W H De Haan, J A Ferreira, Peter Luerkens
    Abstract:

    Symmetry Cockcroft Walton multiplier is a typical cascade voltage multiplier. It is an attractive alternative to the high voltage (HV) transformer with high turn ratio and bridge rectifier in the HV generator in medical X-ray machine. It can reduce the stray capacitance of the HV transformer. However, previous work reports that the parasitic capacitances in the multiplier itself can be added to the stray capacitance of the transformer, which becomes a burden to the resonant capacitance of the generator. Thus, it is crucial to minimize the parasitic capacitances in the multiplier. In this paper, the Complete Model of the parasitic capacitances in the multiplier is exhibited. The Model gives full description of parasitic capacitances in any spatial configuration of the multiplier module. Then, the equivalent capacitance of the Model is obtained and analyzed to exhibit the role of parasitic capacitances in the system circuit. The dependence of the equivalent capacitance on different parameters, such as different groups of parasitic capacitances and the number of diodes per chain, is addressed. Besides, the impact of breakdown of the diodes on the equivalent capacitance is also exhibited. The Complete capacitance Model and the analysis of the equivalent parasitic capacitance are validated by the experimental measurements. In the end, guidelines are concluded for how to minimize the equivalent parasitic.

Jianing Wang - One of the best experts on this subject based on the ideXlab platform.

  • detailed derivation and minimization of the equivalent parasitic capacitances of a high voltage multiplier based on the Complete Model
    IEEE Transactions on Industry Applications, 2015
    Co-Authors: Jianing Wang, Sjoerd W H De Haan, J A Ferreira
    Abstract:

    The authors' previous paper presents the Complete Model of parasitic capacitances in a high-voltage (HV) multiplier in the HV generator in a medical X-ray machine. The equivalent parasitic capacitance of the multiplier $C_{\rm em}$ based on the Model is exhibited to interpret the role of the parasitic capacitances in circuit operation of the generator. Without derivation of the analytical expression of $C_{\rm em}$ , its dependence on the component parameters is directly shown, which leads to guidelines for minimization of $C_{\rm em}$ . However, the Complete capacitance Model has a complicated structure and contains voltage-dependent capacitances and voltage sources, which gives complexity to derivation of $C_{\rm em}$ as well as difficulties to clear understanding of the voltage dependence of $C_{\rm em}$ . Thus, this paper presents the detailed derivation and analytical expression of $C_{\rm em}$ . Exactly speaking, the key part of $C_{\rm em}$ , namely, the total chain capacitance $C_{\rm Dcht}$ that determines the voltage dependence of $C_{\rm em}$ , is conducted. A simple way is presented for the derivation of $C_{\rm Dcht}$ . The derivation enables a clear understanding of the voltage dependence of $C_{\rm Dcht}$ . Moreover, a design procedure for minimization of $C_{\rm em}$ is created, accompanied by a case study. It gives designers step-by-step rules to make an optimal HV multiplier with a minimum $C_{\rm em}$ .

  • Detailed derivation and minimization of the equivalent parasitic capacitance of a high voltage multiplier based on the Complete Model
    2013 IEEE Energy Conversion Congress and Exposition, 2013
    Co-Authors: Jianing Wang, Sjoerd W H De Haan, J A Ferreira
    Abstract:

    This is a follow-up paper to the publication [1]. The previous paper presents the Complete Model of parasitic capacitances of a high voltage (HV) multiplier, which is employed as a capacitive rectifier in HV generator in medical x-ray machine. The equivalent parasitic capacitance of the multiplier Cem based on the Model is exhibited to interpret the role of the parasitic capacitances in circuit operation of the HV generator. Without detailed explanation about derivation of analytical expression of Cem, its dependence on the component parameters are directly shown, which leads to guidelines for minimization of Cem. However, the Complete Model shows a capacitance network with complicated structure and containing voltage-dependent capacitances and constant voltage sources, which gives complexity to derivation of Cem as well as difficulties to clear understanding of the voltage dependence of Cem. Thus, this paper presents the detailed derivation and analytical expression of Cem. Exactly speaking, the key part of Cem, namely the total chain capacitance CDcht that determines the voltage dependence of Cem, is conducted. A simple way is presented for the derivation of CDcht. The derivation can give readers a clear understanding of the voltage dependence of CDcht. Besides the derivation, a design procedure for minimization of Cem is created based on the proposed guidelines in [1], accompanied by a case study. It gives designers step-by-step rules to make an optimal HV multiplier with a minimum Cem.

  • Complete Model of parasitic capacitances in a cascade voltage multiplier in the high voltage generator
    2013 IEEE ECCE Asia Downunder, 2013
    Co-Authors: Jianing Wang, Sjoerd W H De Haan, J A Ferreira, Peter Luerkens
    Abstract:

    Symmetry Cockcroft Walton multiplier is a typical cascade voltage multiplier. It is an attractive alternative to the high voltage (HV) transformer with high turn ratio and bridge rectifier in the HV generator in medical X-ray machine. It can reduce the stray capacitance of the HV transformer. However, previous work reports that the parasitic capacitances in the multiplier itself can be added to the stray capacitance of the transformer, which becomes a burden to the resonant capacitance of the generator. Thus, it is crucial to minimize the parasitic capacitances in the multiplier. In this paper, the Complete Model of the parasitic capacitances in the multiplier is exhibited. The Model gives full description of parasitic capacitances in any spatial configuration of the multiplier module. Then, the equivalent capacitance of the Model is obtained and analyzed to exhibit the role of parasitic capacitances in the system circuit. The dependence of the equivalent capacitance on different parameters, such as different groups of parasitic capacitances and the number of diodes per chain, is addressed. Besides, the impact of breakdown of the diodes on the equivalent capacitance is also exhibited. The Complete capacitance Model and the analysis of the equivalent parasitic capacitance are validated by the experimental measurements. In the end, guidelines are concluded for how to minimize the equivalent parasitic.

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

  • A Complete Model for oxidation air-lift reactors
    Computers & Chemical Engineering, 2001
    Co-Authors: E. Camarasa, L.a.c. Meleiro, E. Carvalho, A. Domingues, R. Maciel Filho, Gabriel Wild, Souhila Poncin, Noël Midoux, Jacques Bouillard
    Abstract:

    Abstract A Complete Model for prediction performance of an oxidation air-lift reactor has been developed. The Model includes reaction kinetics, flow configuration, mass transfer and hydrodynamics. Liquid bulk and gas phases are Modeled using a cell Model. The mass transfer rates are computed from the film Model. Hydrodynamics parameters are calculated with an adequate Model based on balance equations and on experimental data. The Model predicts the variations of concentrations and hydrodynamics parameters along the reactor and hence is able to provide a good description of the reactor.

  • Development of a Complete Model for an air-lift reactor
    Chemical Engineering Science, 2001
    Co-Authors: E. Camarasa, L.a.c. Meleiro, E. Carvalho, A. Domingues, R. Maciel Filho, Gabriel Wild, Souhila Poncin, Noël Midoux, Jacques Bouillard
    Abstract:

    An 1D hydrodynamic Model has been developed for gas hold-up and liquid circulation velocity prediction in air-lift reactors. The Model is based on momentum balance equations and has been adjusted to experimental data collected on a pilot plant reactor equipped with two types of gas distributors and using water and water/butanol as the liquid phase. Agreement between the hydrodynamic Model and pilot experimental points is shown to be fairly good. Different techniques of signal analysis have also been applied to pressure fluctuations in order to extract information about flow regimes and regime transitions. A good knowledge of the flow pattern is essential to establish adequate hydrodynamic correlations. This Model has also been combined with mass transfer and the kinetics of a chemical reaction to yield a Complete Model of the performance of a reactor.