Free Essay

In: Science

Submitted By Bhuwan

Words 1757

Pages 8

Words 1757

Pages 8

Introduction

1.1 Background

AC induction motors are being applied today to a wider range of applications requiring variable speed as they are the leading elements to convert electrical energy into mechanical energy. They are being used as actuators in various industrial processes, robotics, house hold appliances (generally single phase induction motor) and other similar applications. The reason for its day by day increasing popularity can be primarily attributed to its robust construction, simplicity in design and cost effectiveness. Also, induction motors are proved to be more reliable than DC motor.

Generally, variable speed drives for induction motor requires wide operating range of speed and fast torque response, regardless of the load variations. Also, the conventional controllers have to linearize the non-linear system of induction motor in order to calculate the parameters, which is almost impossible to obtain a perfect non-linear model. Hence the values of the parameters that are obtained from it are thereby approximate. This leads us to more advanced control methods to meet the real demand.

To overcome the complexities of conventional controllers, fuzzy logic controller have been implemented in many motor applications. A Fuzzy Logic Controller (FLC) is incorporated for combination with Phase Locked Loop (PLL) for precise and robust speed of induction motor. The fuzzy logic controller is used to pull the motor speed into the locking range of PLL. When the speed error is between the set point speed and the measured speed is larger than the preset value, the motor speed is incremented or decremented by the fuzzy logic controller towards the PLL locking range. In order to achieve excellent speed regulation, PLL control replaces the FLC when speed error is within the locking range of PLL. When the system operates in the phase locked loop, the speed of motor is locked by a reference frequency. Synchronization of motor speed to a very accurate reference frequency warrants that the motor speed will not drift due to temperature or component wear. Thus, a precise speed control of induction motor operation is achieved.

1.2 Objective

The main objective of this project is design a speed control system of the induction motor based on fuzzy logic controller implemented with phase locked loop controller, employing the scalar control model. The voltage and frequency input to the induction motor are to be controlled in order to obtain the desired speed response. This system will be able to control the induction motor speed at desired speed regardless the changes in load.

1.3 Scope

The scope of the project is: a. To learn how to design a control system for a non-linear system. b. To develop an artificially intelligent speed control system for induction motor using phase locked loop and the fuzzy logic approach. c. To produce a learning package of fuzzy logic controller, for scalar speed control of induction motor, for future reference purpose.

Chapter 2

System Overview

2.1 Block Diagram

Fig. 1: Block diagram of proposed induction motor speed control system.

The block diagram of phase locked loop controlled induction motor speed drive system incorporating fuzzy logic controller is illustrated in fig. 1. An ac source is used to provide an ac voltage with adequate power to drive the induction motor at the desired speed. An encoder will be mounted in the motor shaft which serves as the speed feedback unit. The phase locked loop or fuzzy logic controller is employed to control the induction motor speed. When the speed error is larger than the preset value, the fuzzy logic controller is active and when the speed error is within the preset value, the phase locked loop is active. Thus motor speed is accelerated or decelerated towards the set point through fuzzy control where PLL synchronizes with the desired speed.

2.2 Flowchart Fig 2: Flow chart of the proposed induction motor speed control system.

The flowchart of the proposed induction motor speed control system using phase locked loop and fuzzy logic control is illustrated in fig.2. When the motor speed error reaches or within the phase locked loop locking range the system enters to the PLL operation mode. Once the speed error is beyond the preset range, the system will go to the fuzzy logic control mode. Thus a precise speed of induction motor can be achieved. The control mode is selected by the switching logic as shown in fig.1.

Chapter 3

Literature Survey

3.1 Induction Motor

The induction motor finds its place amongst more than 85% of industrial motors as well as in its single phase form in various domestic usages. Also a constant speed motor with shunt characteristics, speed drops only by a few percent from no-load to full load. Hence in past, induction motors have been used primarily in constant speed applications. The speed control of induction motors involves more complicacy than the control of dc motor, especially if comparable accuracy is desired. The main reason for the same can be attributed to the complexity of the mathematical model of induction machine.

Mathematically, the relation between the speed of induction motor and the synchronous speed can be stated as: n = (1 – s) ns (3.1) Also ns = 120 fP (3.2) which implies that there are two basic ways of speed control, namely a. Slip-control for fixed synchronous speed b. Control of synchronous speed

3.2 Phase Locked Loop (PLL)

Phase locked loop is a feedback loop which have been used intensively in systems where accurate frequency is required. The basic PLL has three components connecte.d in a feedback loop, a voltage controlled oscillator (VCO), a phase detector (PD) and a low pass filter (LPF). The VCO is an oscillator whose frequency is proportional to input voltage. The voltage at the input of the VCO determines the frequency of the periodic signal at its output. The VCO output and a periodic input signal (the reference) are inputs to the phase detector. When the loop is locked on the input signal, the frequency of the VCO output is exactly equal to that of a reference. Phase detector produces a signal proportional to the phase difference between the reference signal and the VCO output signal. The phase error signal is filtered by the low pass filter to provide a voltage proportional to the phase difference between the two signals. The loop is closed by connecting the filter output to the input of the VCO. The voltage output of the filter is used to vary the VCO frequency in such a direction that reduces the phase difference. An equilibrium state is reaches when the VCO frequency is exactly equal to the frequency of the reference input signal.

3.3 Fuzzy Logic (FL)

The fuzzy logic is a form of many valued logic or probabilistic logic. It deals with reasoning that is approximate rather than fixed and exact. In contrast with traditional logic they can have varying values, where binary sets have two logic, true or false, fuzzy logic variables may have truth value that ranges in degree between 0 and 1. Fuzzy logic has been extended to handle the concept of partial truth, where the truth value may range completely true and completely false.

Fuzzy logic controller is a technique to embody human like thinking into the control system. Fuzzy logic control can be designed to emulate human deductive thinking i.e. the process people use to infer conclusions from what they know. The fuzzy logic controls have four functions, fuzzification, interface mechanism, knowledge base and defuzzification. a. A fuzzification interface, the fuzzy control initially converts the crisp error and its rate of change in displacement into fuzzy variables, and then they are mapped into linguistic labels of fuzzy sets. Membership functions are defined within the normalized range and associated with each label. All the member functions are symmetrical for positive and negative values of the variables. The proposed controller uses following linguistic labels NB (Negative Big), NM (Negative Medium), NS (Negative Small), ZE (Zero), PS(Positive Small), PM (Positive Medium), PB (Positive Big).

b. A knowledge base involves defining the rules represented as If-Then rules statements governing the relationship between input and output variables in terms of membership function. It contains the definition of fuzzy subsets, their membership functions, their universe discourse and the whole rule of interface to achieve good control.

c. An interface mechanism, also known as interface engine or fuzzy interface module , is a heart of the fuzzy control which posses the capacity of feign the human decisions and emulates the expert’s decision making in interpreting and applying knowledge about how best to control the plant.

d. Defuzzification is a stage which introduces different methods that can be used to produce fuzzy set value for the output fuzzy variables. It is the interface which converts the conclusions of the interface mechanism into actual inputs for the process.

Chapter 4

Discussion & Conclusion

4.1 Discussion

Conventional speed controller for induction motor system requires a complete mathematical model of the motor. Fuzzy logic design uses linguistic description to replace the mathematical model. This can reduce design complexity and expedite the development cycle. However, fuzzy logic alone cannot provide best performance of induction motor speed control both in transient and steady state. Thus the PLL control is used to replace the FLC once the speed error is within a preset limit. When the speed error is larger, the FLC becomes active and the system responds quickly by drawing the motor speed into the preset speed error range.

4.2 Conclusion

The feasibility of using two different controllers i.e. Fuzzy Logic Controller (FLC) in combination with Phase Locked Loop (PLL), for the speed control of induction motor is presented here to obtain a robust and precise speed regulation is presented here. Further study and simulation is needed for the prediction of system behavior. The proposed system offers many advantages such as accurate speed control, synchronization and digital control possibility which can be economically implemented.

Gantt-Chart

Work Accomplished:

Work Remaining:

References 1. V. Chitra, R. S. Prabhakar “Induction Motor Speed Control using Fuzzy Logic Controller” World Academy of Science, Engineering and Technology 23 2006. 2. B. Zaineb, B. H. Mauna, L. Sbita, “Software Digital Phase Locked Loop for Induction Motor Speed Control” International Journal of Electrical And Computer Engineering 5:2 2010. 3. M. Lai, C. Chang, “Fuzzy Logic in the Phase Locked Loop DC Motor Speed Control System”. 4. W. Djatmiko, B. Sutopo, “Speed Control DC Motor under varying load using Phase Locked Loop System”.

Free Essay

...Fuzzy Control Kevin M. Passino Department of Electrical Engineering The Ohio State University Stephen Yurkovich Department of Electrical Engineering The Ohio State University An Imprint of Addison-Wesley Longman, Inc. Menlo Park, California • Reading, Massachusetts Don Mills, Ontaria • Sydney • Bonn • Harlow, England • Berkeley, California • Amsterdam • Mexico City ii Assistant Editor: Laura Cheu Editorial Assistant: Royden Tonomura Senior Production Editor: Teri Hyde Marketing Manager: Rob Merino Manufacturing Supervisor: Janet Weaver Art and Design Manager: Kevin Berry Cover Design: Yvo Riezebos (technical drawing by K. Passino) Text Design: Peter Vacek Design Macro Writer: William Erik Baxter Copyeditor: Brian Jones Proofreader: Holly McLean-Aldis Copyright c 1998 Addison Wesley Longman, Inc. All rights reserved. No part of this publication may be reproduced, or stored in a database or retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States of America. Printed simultaneously in Canada. Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in this book, and AddisonWesley was aware of a trademark claim, the designations have been printed in initial caps or in all caps. MATLAB is a registered trademark of The......

Words: 211473 - Pages: 846

Free Essay

...What Is Fuzzy Logic? Fuzzy Logic: | a form of mathematical logic in which truth can assume a continuum of values between 0 and 1. | | Princeton Web Dictionary Fuzzy logic is a form of logic with more than two values. Formally it can be called as probabilistic logic and it simply deals with approximated values rather than exact ones; as in daily language, it includes grays along with black and white. It is also accepted as a problem solving control system methodology. Fuzzy logic is a type of logic that recognizes more than only true and false values. With fuzzy logic, variables can be represented with degrees of truthfulness and falsehood. As an example ‘today is sunny’ statement can be used; this statement, might be 100% true if there are absolutely no clouds, 80% true if there are a few clouds, 50% true if it's partly cloudy and 0% true if it rains all day. Advantages of fuzzy logic can be listed as: * Fuzzy logic is easy to understand. * Fuzzy logic is flexible. * Fuzzy logic is based on natural language. * Fuzzy logic can model nonlinear functions of arbitrary complexity. Advantages of fuzzy logic continued: * Fuzzy logic is tolerant of imprecise data. * Fuzzy logic can be blended with conventional control techniques. * Fuzzy logic can be built on top of the experience of experts. * Fuzzy logic does not solve new problems. It uses new methods to solve everyday problems. * Mathematical concepts within fuzzy......

Words: 1219 - Pages: 5

Free Essay

...Title :Wind speed prediction using Artificial Neural Network (ANN) Abstract : The crisis of fossil based fuel around the world has led to the research of Renewable Energy sources. One of the oldest sources of Renewable energy was using the wind to generate electrical or mechanical power using windmills. To use it efficiently the wind speed which determines the wind power must be known beforehand. Wind speed is a random variable depending on meteorological variables like atmospheric pressure,temperature,relative humidity & such. Methods that are currently being applied to predict wind speed are Statistical, Intelligent systems, Time series, Fuzzy logic, neural networks.Our focus will be on using Artificial Neural Network to predict the wind speed in daily basis in this report. Chapter 1 1.1 Introduction Bangladesh has a 724 lm long coastal area where south-westerly tradewind& sea breeze makes the usage of wind as a renewable energy source very visible. But, not much systematic wind study has been made, adequate information on the wind speed over the country and particularly on wind speeds at hub heights of wind machines is not available. A previous study (1986) showed that for the wind monitoring stations of Bangladesh Meteorological Department (BMD) the wind speed is found to be low near the ground level at heights of around 10 meter. Chittagong – Cox’s Bazar seacoast and coastal off-shore islands appeared to have better wind speeds.......

Words: 4034 - Pages: 17

Free Essay

...Dissertation Phase-I: Synopsis Topic: OPTIMUM THRESHOLDING USING FUZZY TECHNIQUES Guided by- Presented by- Mr.Puneet Manocha Anupama (Roll No.1600872) Assit. Professor IIIrd Semester, M.Tech (ICE) OBJECTIVE: * To review different research papers based on Fuzzy Thresholding. * To apply fuzzy thresholding technique to an image * To calculate optimum threshold using Gamma membership function. LITERATURE REVIEW: Introduction: Typical computer vision applications usually require an image segmentation-preprocessing algorithm as a first procedure. At the output of this stage, each object of the image, represented by a set of pixels, is isolated from the rest of the scene. The purpose of this step is that objects and background are separated into non-overlapping sets. There are various techniques of segmentation and among them threshold is much simpler than other segmentation techniques. Usually, this segmentation process is based on the image gray-level histogram. In that case, the aim is to find a critical value or threshold. Through this threshold, applied to the whole image, pixels whose gray levels exceed this critical value are assigned to one set and the rest to the other. For a well-defined image, its histogram has a deep valley between two peaks. Around these peaks the object and......

Words: 2221 - Pages: 9

Free Essay

...An Industry-oriented Mini-Project Report on WIRELESS DC MOTOR SPEED AND DIRECTION CONTROL USING RF COMMUNICATION Submitted to Department of Electronics and Communication Engineering Mahaveer Institute of Science and Technology (Approved by AICTE) and affiliated to JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY Hyderabad, (A.P.). in partial fulfillment of the Requirement for the award of Degree of BACHELOR OF TECHNOLOGY in Electronics & Communication Engineering Submitted By K. Vinay 08E31A04C8 GUIDE MINI-PROJECT COORDINATOR HEAD OF DEPT. Mr. Sridhar Chitta Mr. M. Nagaraju Naik Dr. B. Visvesvara Rao . MAHAVEER INSTITUTE OF SCIENCE & TECHNOLOGY Vyasapuri, Bandlaguda, Post: Keshavgiri, Hyderabad – 500 005 2011 - 2012 CERTIFICATE This is to certify that the mini project work titled WIRELESS DC MOTOR SPEED AND DIRECTION CONTROL USING RF COMMUNICATION, which is being submitted By K. Vinay 08E31A04C8 in partial fulfilment for the award of Degree of Bachelor of Technology in Electronics and Communication Engineering to the Mahaveer Institute of Science and Technology, affiliated to Jawaharlal Nehru Technological University and is a bonafide record of work carried out by them under our supervision. The results embodied in this mini-project report have not been submitted to any other University or Institute for the award of any degree or diploma. Project Guide Project Coordinator ......

Words: 1425 - Pages: 6

Free Essay

...Almost all machines in industries are operated using electrical motors. Among them most of the motors are DC motors. DC series motor is specially used for traction, electric locomotive, trolley systems, crane and conveyer belt. All these works require frequent speed control for the preparation of job. We could gear the motor for the proper speed, but this is usually beyond scope of what we can accomplish in the basement workshop or we could measure the current that the motor draws and determine a series resistor value according to ohms law to insert to “drop” the motor supply voltage and slow the motor down. The problem with this approach is that if load on the motor increases, the motors operating current also increases, creating a larger voltage drop across that series resistor and supplying less voltage to the motor terminals when it is needed the most. This “vicious circle” usually results in the motor stalling at high load conditions. So what we need is a controller that will give the motor a kick of supply voltage for a variable amount of time to achieve the proper speed without the series dropping effect. A PWM (Pulse width modulation) wave can be used to control the speed of the motor. CHAPTER 2 WIRELESS COMMUNICATIONS Wireless communication is the transfer of information over distance without the use of electrical conductors or “wire”. The distances involved maybe short (a few meters as in television remote control) or long (thousands or millions of kilometers......

Words: 3592 - Pages: 15

Free Essay

...DESIGN OF FUZZY PID CONTROLLER FOR SPEED CONTROL OF BLDC MOTOR PHASE I REPORT Submitted by ARJUN M Register No. 710012428003 in partial fulfilment for the award of the degree of MASTER OF ENGINEERING in CONTROL AND INSTRUMENTATION DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING ANNA UNIVERSITY REGIONAL CENTRE, COIMBATORE COIMBATORE-641 047 DECEMBER 2013 ii ANNA UNIVERSITY REGIONAL CENTRE, COIMBATORE COIMBATORE-641 047 DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING PROJECT WORK PHASE I DECEMBER 2013 This is to certify that the project entitled DESIGN OF FUZZY PID CONTROLLER FOR SPEED CONTROL OF BLDC MOTOR is the bonafide record of project work done by ARJUN M Register No: - 710012428003 Of M.E. (CONTROL AND INSTRUMENTATION) during the year 2013-2014 Head of the Department Dr.S.N.DEEPA, M.E., Ph.D., Project Guide Mr.P.HARI KRISHNAN, M.E., Submitted for the Project Viva-Voce examination held on Internal Examiner External Examiner iii DECLARATION I affirm that the project titled DESIGN OF FUZZY PID CONTROLLER FOR SPEED CONTROL OF BLDC MOTOR being submitted in partial fulfilment for the award of Master of Engineering (M.E.) in Control and Instrumentation is the original work carried out by me. It has not formed the part of any other project work submitted for award of any degree or diploma, either in this or any other University. Signature of the Candidate ARJUN M Register......

Words: 7692 - Pages: 31

Premium Essay

...Speed Control of Induction Motor using Fuzzy Logic Approach A PROJECT THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Bachelor of Technology In Electrical Engineering By Varuneet Varun (Roll 108EE011) G. Bhargavi (Roll 108EE026) Suneet Nayak (Roll 108EE044) Under Supervision of Prof. Kanungo Barada Mohanty Department of Electrical Engineering National Institute of Technology, Rourkela Rourkela- 769008, Odisha © 2011 - 2012 National Institute of Technology Rourkela Certificate This is to certify that the work contained in this thesis, titled “SPEED CONTROL OF INDUCTION MOTOR USING FUZZY LOGIC APPROACH” submitted by Varuneet Varun, G. Bhargavi and Suneet Nayak is an authentic work that has been carried out by them under my supervision and guidance in partial fulfillment for the requirement for the award of Bachelor of Technology Degree in Electrical Engineering at National Institute of Technology, Rourkela. To the best of my knowledge, the matter embodied in the thesis has not been submitted to any other University/ Institute for the award of any Degree or Diploma. Place: Rourkela Date: 11th May, 2012 Dr. Kanungo Barada Mohanty Associate Professor Department of Electrical Engineering National Institute of Technology Rourkela – 769008 i Acknowledgment We are grateful to The Department of Electrical Engineering for giving us the opportunity to carry out this project, which is an......

Words: 17434 - Pages: 70

Free Essay

...International Review of Business Research Papers Vol.2. No.4. December 2006, Pp. 39-50 eBusiness-Process-Personalization using Neuro-Fuzzy Adaptive Control for Interactive Systems Zunaira Munir1 , Nie Gui Hua2 , Adeel Talib3 and Mudassir Ilyas4 ‘Personalization’, which was earlier recognized as the 5th ‘P’ of e-marketing , is now becoming a strategic success factor in the present customer-centric e-business environment. This paper proposes two changes in the current structure of personalization efforts in ebusinesses. Firstly, a move towards business-process personalization instead of only website-content personalization and secondly use of an interactive adaptive scheme instead of the commonly employed algorithmic filtering approaches. These can be achieved by applying a neuro-intelligence model to web based real time interactive systems and by integrating it with converging internal and external e-business processes. This paper presents a framework, showing how it is possible to personalize e-business processes by adapting the interactive system to customer preferences. The proposed model applies Neuro-Fuzzy Adaptive Control for Interactive Systems (NFACIS) model to converging business processes to get the desired results. Field of Research: Marketing, e-business 1. Introduction: As Kasanoff (2001) mentioned, the ability to treat different people differently is the most fundamental form of human intelligence. "You talk differently to your boss than......

Words: 4114 - Pages: 17

Free Essay

...Neighborhood Speed Control By Charles Russell, 21 May 2011 Thesis: Changing our neighborhood traffic speed so everyone can be safe, when they want to take a walk, jog down the road and or even ride their bikes but most important, protecting their most valuable asset; their children. There is a beautiful upscale Washington DC suburb called “Kingstown” located in Alexandria, VA. This is the area my family and I decided to live about five years ago. We purchase a townhouse located off a street called “Chelsea Search Way” which is a cuddly sac off another street named “Summer Ridge.” This is the main street going through our neighborhood and links many cuddle sacs together. Summer Ridge is like one big loop that turns off of Kingstown Village Parkway and then reconnects after a mile and a half. Summer Ridge is one of the liveliest streets neighborhoods you would ever see. Everywhere you look there are small children playing, people walking their dogs, joggers running and bicyclist’s riding. The only problem with this is that this neighborhood could be one of the most dangerous places because there is a lot of traffic going up and down this road. Each year over 4,000 sons, daughters, mothers & fathers were killed while walking in their neighborhoods or crossing streets. Fairfax County must not understand that there is a problem here, because the speed limit was set at 25 miles per hour, which I believe is way too fast for such a playground. Not only the speed is the......

Words: 568 - Pages: 3

Free Essay

...Design of Five Phase Induction Motor Sanket M. Bhimgade#1 Swapnil C. Chaudhari#2 Roshan B. Durge#3 Vabeihrohnei Chozah#4 Parag P. Salunke#5 Department of Electrical Engineering Dr. Babasaheb Ambedkar Technological University, Lonere, Raigad (MS - 402 103) sanketbhimgade@gmail.com , 2swapnil.28492@gmail.com , 3roshan.durge16@gmail.com , 4pawhrohnei@gmail.com , 1 Abstract: The conversion of electrical energy into mechanical energy has been and continuous to be a dominant form of power transmission for industrial purposes. The alternating current (AC) electric induction motor has been an industry workhouse for electromechanical conversion for over 100 years. This paper introduces the fundamental electric and mechanical principles of 5 phase AC induction motor. In this paper, a generalized formula is proposed for the selection of number of slots required for 5-phase alternative current (AC) machine design and the criterion for selecting the starting points of each phases. Keywords: Induction motor. Five phase, Stator winding. current. The power per phase is P = VP IP cosϕ and the total power is the sum of the amount of power in each phase. If the currents are equal and the phase angles are the same as in Fig. 1, then the load on the system is balanced, the current in the neutral is zero and the total power is [1], =3 cos ∅ Or Or = √3 = 1.73 cos ∅ cos ∅ I. INTRODUCTION In general, the induction machines having......

Words: 3545 - Pages: 15

Premium Essay

...A Review of Induction Motors Pattinson Hayton California State University, Long Beach College of Engineering 12/03/2015 Thus far in Energy Conversion and Principles, the topics of direct current, or DC, and synchronous motors have been covered and discussed. A direct current exists in the field windings of both of these motors and an alternating current, or AC, exists in the armature windings of both of these motors. Electrical power is delivered right to the armature of a DC motor using a commutator, or the moving part of the rotary, in these motors. Because of this, a DC motor with this type of connection can also be referred to as a conduction motor. Conversely, if a motor receives power by induction, rather than by conduction, the motor is called an induction motor. An induction motor is therefore a type of transformer that possesses a rotary secondary winding. As discussed previously, both DC and synchronous motors are doubly-fed. An induction motor, however, is a singly-fed motor. With these motors being singly-fed, the construction of is different than that of other motors. These motors do not require slip-rings, a commutator, or brushes. With these components absent from induction motors, it is thus seen that there are no moving contacts between the stator and rotors, which is obviously quite different than the structure of DC and synchronous motors. Induction motors are useful due to their efficiency. The absence of brushes in induction motors eliminates......

Words: 3796 - Pages: 16

Free Essay

...Designing a Speed Control system of a DC motor based on PID algorithm using MATLAB SIMULINK DC motors have variable characteristics and are used extensively in variable-speed drives. DC motor can provide a high starting torque and it is also possible to obtain speed control over wide range. Why do we need a speed motor controller? For example, if we have a DC motor in a robot and we just apply a constant power to each motor on a robot, then the poor robot will never be able to maintain a steady speed. It will go slower over carpet, faster over smooth flooring, slower up hill, faster downhill, etc. So, it is important to make a controller to control the speed of DC motor in desired manner. And that’s why we are now interested to design a control system named PID. Now if we want to define the PID control system,then it will be like this A block diagram of PID Control system Now if we want to discuss about the algorithm behind this control system then,it constritutes of three basic part all comes from the following equation: The Characteristics of P, I, and D Controllers A proportional controller ( ) will have the effect of reducing the rise time and will reduce but never eliminate the steady-state error. An integral control ( ) will have the effect of eliminating the steady-state error for a constant or step input, but it may make the transient response slower. A derivative control ( ) will have the effect of increasing the stability of......

Words: 510 - Pages: 3

Premium Essay

...ac rotating machine whose speed under steady state condition is proportional to the frequency of the current in its armature. The magnetic field created by the armature currents rotates at the same speed as that created by the field current on the rotor, which is rotating at the synchronous speed and a steady torque. Synchronous machines are commonly used as generators especially for large power systems, such as turbine generators and hydroelectric generators in the grid power supply. Because the rotor speed is proportional to the frequency of excitation, synchronous motors can be used in situations where constant speed drive is required. Chapter IV EPM1076 3 Chapter IV EPM1076 4 Angle in Electrical and Mechanical Unit -For 2 pole machine, when the rotor rotates for one revolution, the induce emf varies for one cycle. i.e. θ = θm, (refer to figure 2) -Where θ is the angle in electrical degrees or radians and θm is the mechanical angle. - For a 4 pole machine, as the rotor rotates for one revolution (θm = 2π), the induced emf varies for two cycles (θ = 4π) (refer to figure 2) -Hence, θ = 2θm or in general, θ = (P/2) θm (Eqn 1) -Where P = number of pole. Chapter IV EPM1076 5 Figure 2 2 pole 4 pole back Chapter IV EPM1076 6 By taking derivatives on both side of Eqn 1. ω = (P/2) ωm Where ω is the angular frequency of emf in electrical radian per second and ωm the angular speed of the rotor in......

Words: 2662 - Pages: 11

Premium Essay

...Abstract In recent years fuzzy set theory has emerged as a transcendental tool to deal with environmental engineering application having uncertainty, ambiguity and subjectivity. Analysis of surface water quality plays significant role in environmental impact assessment studies. For qualitative description of surface water quality, number of physical, chemical and biological parameters are taken into consideration, allotted a weightage factor and calculated into an index called water quality index (WQI). Water quality index uses crisp set to analyse water contaminants and hence deals with standing boundary conditions. This paper illustrates use of fuzzy inference system for analysing physical and chemical parameters to assess surface water quality. A water quality index calculated with fuzzy inference system has been developed and discussed. Introduction Determination of status of water quality of a river or any other water sources is highly indeterminate. The current method of determining water quality index which is in practice utilizes statistical approach and is not precise in most of the time. Nowadays environmental protection and water quality management has become an important issue in public policies throughout the world. Moreover, government is concerned about the quality of their environmental resources because of the complexity in water quality data sets. Many countries have introduced a scheme for river water quality monitoring and assessment,......

Words: 2334 - Pages: 10