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N. Govind - One of the best experts on this subject based on the ideXlab platform.

  • Rule-based intelligent control with embedded microcontrollers
    IEEE Technical Applications Conference. Northcon 96. Conference Record, 1
    Co-Authors: N. Govind
    Abstract:

    Fuzzy logic control is being increasingly applied to solve control problems in areas where system complexity, development time and cost are the major issues. In the absence of a system mathematical model, a fuzzy system model is described which is analogous to a human operator's behavior, based on approximate reasoning bound by a minimum set of rules. A set of linguistic fuzzy control rules are set up which are conditional linguistic statements which establish the relationships between the inputs and the outputs. The motor speed is controlled by controlling the armature voltage Va. This technique is used by the author as a fundamental basis for the fuzzy controller synthesis. To comply with the torque demand requirements, the armature current and Field currents are maintained at a constant level for motor speeds less than the base speed and the speed is controlled by varying the armature voltage. The Field current can be varied to control the speed by maintaining the armature voltage at a constant level for motor speeds higher than the base speed. But, Field current is not varied here, since speed control is below the base speed. The armature is supplied with different voltages with the Shunt Field of the motor permanently connected to a constant exciting voltage. The main supply is ac which is converted to dc by using a bridge circuit. Silicon controlled rectifiers (SCR) are used to vary the mean voltage supplied to the de motor by firing the SCR at varying angles of the input sine wave. The speed of the motor is more or less proportional to the varying supply voltages.

  • Rule based approximate reasoning for intelligent control
    Southcon 96 Conference Record, 1
    Co-Authors: N. Govind
    Abstract:

    Fuzzy logic control is being increasingly applied to solve control problems in areas where system complexity, development time and cost are the major issues. In the absence of a system mathematical model, a fuzzy system model is described which is analogous to a human operator's behavior, based on approximate reasoning bound by a minimum set of rules. A set of linguistic fuzzy control rules are set up which are conditional linguistic statements which establish the relationships between the inputs and the outputs. The motor speed is controlled by controlling the armature voltage Va. This technique is used by the author as a fundamental basis for the fuzzy controller synthesis. To comply with the torque demand requirements, the armature current and Field currents are maintained at a constant level for motor speeds less than the base speed and the speed is controlled by varying the armature voltage. The Field current can be varied to control the speed by maintaining the armature voltage at a constant level for motor speeds higher than the base speed. But, Field current is not varied here, since speed control is below the base speed. The armature is supplied with different voltages with the Shunt Field of the motor permanently connected to a constant exciting voltage. The main supply is AC which is converted to DC by using a bridge circuit. Silicon controlled rectifiers (SCR) are used to vary the mean voltage supplied to the DC motor by firing the SCR's at varying angles of the input sine wave. The speed of the motor is more or less proportional to the varying supply voltages.

Golam Kibria - One of the best experts on this subject based on the ideXlab platform.

  • An Efficient Method for Speed Control of DC Shunt Motor using Response Surface Methodology (RSM) Approach
    2011
    Co-Authors: Golam Kibria
    Abstract:

    The fundamental equations governing the operation of a dc motor are straightforward and are well presented in most undergraduate curricula, usually in a required energy-conversion or electrical-machinery class at the junior level. The physical implications of the equations regarding device behaviour, and the need for speed control, are easily understood. The present research work deals with the application of Response Surface Methodology (RSM) for controlling as well as estimating the rotating speed of a DC Shunt motor. As the rotating speed of DC Shunt motor depends on armature voltage and Field current applied to the Shunt motor, therefore, these two process parameters were varied during experimentation. Central composite design of experiments based experimental designed has been applied and 13 number of experiments have been performed. Moreover, empirical model has been developed to predict any desired speed of rotation of the DC Shunt motor and the model has been validated through confirmation experimentations. The present paper will be useful for the students to readily draw a mental picture regarding the rotating speed of the Shunt motor and applied voltage and current. The response surface method has been successfully applied to overcome the speed-control problem. the motor reaches its full rpm, its speed will remain fairly constant. The Shunt motor's speed can be varied in two different ways. These include varying the amount of current supplied to the Shunt Field and controlling the amount of current supplied to the armature. Controlling the current to the Shunt Field allows the rotating speed to be changed at 10-20% when the motor is at full rotational speed. This type of speed control regulation is accomplished by slightly increasing or decreasing the voltage applied to the Field. The armature continues to have full voltage applied to it while the current to the Shunt Field is regulated by a rheostat that is connected in series with the Shunt Field. When the Shunt Field's current is decreased, the motor's rpm will increase slightly. When the Shunt Field's current is reduced, the armature must rotate faster to produce the same amount of back EMF to keep the load turning. If the Shunt Field current is increased slightly, the armature can rotate at lower rpm and maintain the amount of back EMF to produce the armature current to drive the load. The Field current can be adjusted with a Field rheostat or an silicon control rectifier (SCR) current control. The Shunt motor's rpm can also be controlled by regulating the voltage that is applied to the motor armature. This means if the motor is operated on less voltage than is shown on its data plate rating, it will run at less than its full rpm. You must remember that the Shunt motor's efficiency will drop off drastically when it is operated below its rated voltage. The motor will tend to overheat when it is operated below full voltage, so motor ventilation must be provided. The motor's torque is reduced when it is operated below the full voltage level. Since the armature draws more current than the Shunt Field, the control resistors were much larger than those used for the Field rheostat.

Walter J. Konstanty - One of the best experts on this subject based on the ideXlab platform.

  • Commutation of DC motors operated at reduced Field current
    Conference Record of 2009 Annual Pulp and Paper Industry Technical Conference, 2009
    Co-Authors: Richard D. Hall, Walter J. Konstanty
    Abstract:

    DC motors have been the workhorse of variable speed drives in the paper industry for many years. DC motor speed is easily controlled by varying the supplied armature voltage and/or excitation (Field) current. Many mills have inquired about operating motors beyond the original motor rating. With armature voltage limited by the drive, motor speed may be increased by reducing the Shunt Field current, but not without consideration of vibration, machine adjustment, brush performance, and possible commutation issues because the machine was not designed and tested at those conditions. This paper examines and presents test/Field data displaying the effects of Field weakening on DC machine performance and maintenance.

Ahmad Faizal - One of the best experts on this subject based on the ideXlab platform.

  • Perancangan Pengendali Kecepatan Motor DC Shunt Menggunakan Metode Sliding Mode Control (SMC) dan Proposional Integral Derivative (PID)
    2015
    Co-Authors: Ahmad Faizal
    Abstract:

    Shunt DC motor is a DC motor excitation own type of parallel. Shunt Field coil windingsare made withlots oftiny wires that have a high resistivity. This is because the Shunt DC motor has a simple construction, relatively cheap, and easy maintenance. The down side of Shunt DC motor is the motor speed and load torque is relatively difficult to set up. In the event of load changes, the DC Shunt motor speed will decrease . To get a constant speed and improve the performance of the motor DC Shunt to changes in load , then the need for a Shunt DC motor arrangement. In this reseach of the control system on as hunt DC motor speed control. Control technique used is the sliding mode controller and proposinal integral derivative. Based on the observations, the results obtained show that both controllers are sliding mode controller and PID can be used at the plants hunt DC motor speed control. But the results of the comparison speed and control signals simulation show sthat the successive sliding mode controller produces better speed performance than the sliding mode controller with fast transient time in which obtained τ= 0.020s, ts = 0.5%= 0.1, 2%= 0.08, 5%= 0.06s, tr = 0.588s, and td = 0.0138s, overshoot = 0.71%, Error Steady State = 25, and Time Peak (TP) = 375 s.And control signals in successive sliding mode transient time obtained τ = 0.012s, ts = 0.5%= 0.06, 2%= 0.048, 5%= 0.036s, tr =0.0353s, and td = 0.0831s, overshoot = 0.2%, Error Steady State = 5, and Peak Time (TP) = 30 s. . Keywords: Control, DC motor Shunt , PID, sliding mode

Chia-fu Lin - One of the best experts on this subject based on the ideXlab platform.

  • Aircraft starter/generator control unit design
    Journal of the Chinese Institute of Engineers, 2001
    Co-Authors: Min‐shyan Hwang, Chia-fu Lin
    Abstract:

    Abstract This research aims to develop a controller for aircraft starter/generators using a digital signal processor (DSP) TMS320C25. A starter/generator is a DC machine carrying on two reverse operations - motor and generator. The whole control activity includes current control for motor operation, voltage control for generator operation, and electronics actions in the transitions for mode changes. Field control is the key issue of this research. A PWM DC chopper is employed for the Field drive. A switching type of Shunt Field resistances is proposed to armature current control so that the motor operation can maintain sufficient output torque for engine starting. A DSP voltage regulator is prototyped and verified. The switching nature of the PWM drive makes variable structure control (VSC) a reasonable choice for control design. The experimental results demonstrate that VSC has much better performance than a continuous PI controller. Robustness tests against rotating speed and load current variations als...