The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform

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

  • Study of a Modified Differential Inductance Measurement Circuit as Position Transducer of a Power Cylinder
    IEEE Transactions on Instrumentation and Measurement, 2012
    Co-Authors: Satish Chandra Bera, R. Sarkar, Madan Bhowmick
    Abstract:

    A power cylinder is essential equipment in process industries. Since it acts as a Final Control Element with its piston positioned by a positioner having an input signal from a Controller, the indication of actual position of the piston becomes very much important in analyzing the actual operation of a process. In this paper, a modified differential inductance measurement circuit has been proposed to design the position transducer of a power cylinder. The design of the circuit, along with the principle of operation, has been described in this paper. The operation of the proposed circuit has been experimentally studied, and the experimental results are reported in this paper. The proposed transducer has been found to have very good linearity and repeatability.

  • A novel technique of using a thyristor driven pump as the Final Control Element and flow indicator of a flow Control loop
    ISA transactions, 2011
    Co-Authors: Satish Chandra Bera, N. Mandal, R. Sarkar
    Abstract:

    In the present paper, design of a flow Control loop using a thyristor driven pump as Final Control Element has been described. In this technique, the load current of a thyristor driven pump motor has been utilized as a mass flow sensing parameter of a fluid passing through a pipeline. This thyristor driven pump has been utilized as a Final Control Element of a flow Control loop and the speed of the pump has been selected as the manipulated variable. The non-linearity between the thyristor input signal and pump output has been eliminated by using a modified PID Control technique with inverse derivative Control action. Thus without using any conventional flow meter and Control valve only the thyristor driven pump has been utilized both as the Final Control Element and flow indicating device by using the proposed technique. The whole system has been designed, fabricated and tested by using tap water as the flowing liquid through a pipe line. The experimental results along with the theoretical analysis are compared and reported in the paper.

Stephen J. Boyle - One of the best experts on this subject based on the ideXlab platform.

  • Optimizing valve actuator parameters to enhance Control valve performance
    ISA Transactions, 1996
    Co-Authors: Raymond P. Champagne, Stephen J. Boyle
    Abstract:

    Abstract The market demands for higher quality products have increased the need for reduced process variation. One factor in the quality of the Final end product is the improvement of the Control loop performance. A critical component in the loop is the Final Control Element, the Control valve package. Optimized actuator parameters play a vital role in the dynamic performance of the Control valve. This paper reviews the pneumatic actuator and positioner parameters that effect the Control package performance. This is done through the use of a Control valve package computer model to assess the dynamic performance. The attributes of spring return versus double acting actuators are illustrated. The effects of supply pressure, step size, load margin, and flow, actuator volume and design style are investigated through the use of mathematical simulations of Control valve dynamic performance.

O. I. Bashnin - One of the best experts on this subject based on the ideXlab platform.

  • HYDROTECHNICAL CONSTRUCTION SAYANO-SHUSHENSKAYA CATASTROPHE — SYNCHRONOUS HYDROACOUSTIC RESONANCE?
    2013
    Co-Authors: O. I. Bashnin
    Abstract:

    Two models are considered for propagation of acoustic waves in the water conduits of Francis turbines at hydroelectric power plants (HPP). Transfer functions are cited for a dynamic “pressure-conduitturbinedrafttube” system during a pressure disturbance beyond the turbine. Fulfillment of the Nyquist criterion for the above-mentioned system indicates its stability at any openings of the Final-Control Element. Analysis of analytical relationships between frequency characteristics and parameters characterizing the wave properties of sections of the water conduit makes it possible to isolate frequency regions in which manifestation of resonance is possible, and also evaluate its amplitude. The frequency response of the water conduit at the SayanoShushenskaya HPP, for which three resonances are isolated in the ultra-low acoustic region is given in the conclusion. A mathematical model of the process is developed and investigated. Oscillograms of pressure pulsation during pressure disturbances in the Final third of the draft tube are presented. Results of the investigation are compared with published data derived from full-scale tests.

  • Sayano-Shushenskaya catastrophe — synchronous hydroacoustic resonance?
    Power Technology and Engineering, 2013
    Co-Authors: O. I. Bashnin
    Abstract:

    Two models are considered for propagation of acoustic waves in the water conduits of Francis turbines at hydroelectric power plants (HPP). Transfer functions are cited for a dynamic “pressure-conduit/turbine/draft-tube” system during a pressure disturbance beyond the turbine. Fulfillment of the Nyquist criterion for the above-mentioned system indicates its stability at any openings of the Final-Control Element. Analysis of analytical relationships between frequency characteristics and parameters characterizing the wave properties of sections of the water conduit makes it possible to isolate frequency regions in which manifestation of resonance is possible, and also evaluate its amplitude. The frequency response of the water conduit at the Sayano-Shushenskaya HPP, for which three resonances are isolated in the ultra-low acoustic region is given in the conclusion. A mathematical model of the process is developed and investigated. Oscillograms of pressure pulsation during pressure disturbances in the Final third of the draft tube are presented. Results of the investigation are compared with published data derived from full-scale tests.

Satish Chandra Bera - One of the best experts on this subject based on the ideXlab platform.

  • Study of a Modified Differential Inductance Measurement Circuit as Position Transducer of a Power Cylinder
    IEEE Transactions on Instrumentation and Measurement, 2012
    Co-Authors: Satish Chandra Bera, R. Sarkar, Madan Bhowmick
    Abstract:

    A power cylinder is essential equipment in process industries. Since it acts as a Final Control Element with its piston positioned by a positioner having an input signal from a Controller, the indication of actual position of the piston becomes very much important in analyzing the actual operation of a process. In this paper, a modified differential inductance measurement circuit has been proposed to design the position transducer of a power cylinder. The design of the circuit, along with the principle of operation, has been described in this paper. The operation of the proposed circuit has been experimentally studied, and the experimental results are reported in this paper. The proposed transducer has been found to have very good linearity and repeatability.

  • A novel technique of using a thyristor driven pump as the Final Control Element and flow indicator of a flow Control loop
    ISA transactions, 2011
    Co-Authors: Satish Chandra Bera, N. Mandal, R. Sarkar
    Abstract:

    In the present paper, design of a flow Control loop using a thyristor driven pump as Final Control Element has been described. In this technique, the load current of a thyristor driven pump motor has been utilized as a mass flow sensing parameter of a fluid passing through a pipeline. This thyristor driven pump has been utilized as a Final Control Element of a flow Control loop and the speed of the pump has been selected as the manipulated variable. The non-linearity between the thyristor input signal and pump output has been eliminated by using a modified PID Control technique with inverse derivative Control action. Thus without using any conventional flow meter and Control valve only the thyristor driven pump has been utilized both as the Final Control Element and flow indicating device by using the proposed technique. The whole system has been designed, fabricated and tested by using tap water as the flowing liquid through a pipe line. The experimental results along with the theoretical analysis are compared and reported in the paper.

Douglas J. Cooper - One of the best experts on this subject based on the ideXlab platform.

  • Extension of IMC tuning correlations for non-self regulating (integrating) processes
    ISA transactions, 2007
    Co-Authors: Jeffrey E. Arbogast, Douglas J. Cooper
    Abstract:

    The filter term of a PID with Filter Controller reduces the impact of measurement noise on the derivative action of the Controller. This impact is quantified by the Controller output travel defined as the total movement of the Controller output per unit time. Decreasing Controller output travel is important to reduce wear in the Final Control Element. Internal Model Control (IMC) tuning correlations are widely published for PI, PID, and PID with Filter Controllers for self regulating processes. For non-self regulating (or integrating) processes, IMC tuning correlations are published for PI and PID Controllers but not for PID with Filter Controllers. The important contribution of this work is that it completes the set of IMC tuning correlations with an extension to the PID with Filter Controller for non-self regulating processes. Other published correlations (not based upon the IMC framework) for PID with Filter Controllers fix the filter time constant at one-tenth the derivative time regardless of the model of the process. In contrast, the novel IMC correlations presented in this paper calculate a filter time constant based upon the model of the process and the user's choice for the closed-loop time constant. The set point tracking and disturbance rejection performance of the proposed IMC tunings is demonstrated using simulation studies and a bench-scale experimental system. The proposed IMC tunings are shown to perform as well as various PID correlations (with and without a filter term) while requiring considerably less Controller action.