Chapter 6 choppercontrolled dc brush motor drives 6. It is used for armature voltage control in dc brush motor drives. Matlab closed loop control of chopper fed dc motor. The chopper can he switched at very high frequencies. Chopper control of separately excited dc motor circuit globe. Chopper control of separately excited dc motor the chopper converts the fixed dc voltage to variable dc voltage. The speed of the drives needs to be controlled according to its applications. Adle and rajesh rane accepted 22 july 20, available online 01 august 20, vol.
All we need to do is to keep daxis stator current constant. Practice problems control of dc drives and special machines. The reason behind using pi controller is it removes the delay and provides fast control. It simply chops fixed dc and generates variable dc. Characteristics of dc drives the dc motor works on the principle that speed of the shaft is a direct function of the applied armature voltage. Chopper fed speed control of dc motor using pi controller. The basic approach of closedloop speed control below and above the speed is explained by the drive of fig. The speed of a dc motor can be controlled by 3 methods. Dc choppers applications in dc motor drives and renewable energies many industrial applications need a conversion of a voltage coming from a dc source into another dc level. The thyristorconverter offers greater efficiency, faster response, lower maintenance, smaller size and smooth control. For over 60 years, minarik drives has led the industry with stateoftheart motor control solutions for dc motors under 5 hp.
Before enlisting the practical applications of the drives used for. A braking chopper is an electrical switch that limits the dc bus voltage by switching the braking energy to a resistor where the braking energy is converted to heat. A dc chopper is used to control the speed of a separatelyexcited dc motor. Modeling and control of dc chopper fed brushless dc motor. Chopper controlled dc drives free download as powerpoint presentation. To design and implement speed and direction of four quadrant chopper circuit, dc motor can be control. Chopper fed dc drives separately excited dcm current. A chopper is a device that converts fixed dc input to a variable dc output voltage directly. Chopper fed dc drives a dc chopper is connected between a fixedvoltage dc source and dc motor to vary the armature voltage.
In simscape electrical specialized power systems software, the fourquadrant chopper dc drive block is commonly called the dc7 motor drive. Feb 10, 20 chopper fed dc drives a dc chopper is connected between a fixedvoltage dc source and dc motor to vary the armature voltage. This paper presents modelling and numerical simulation as well as prototype for speed control of dc series motor using a dc chopper. The variable dc voltage is controlled by varying the on and offtimes of a converter.
This overview is intended to outline to users, plant managers, industrial design engineers or the persons responsible for a particular process the features offered by dc drives as compared to ac drives. This paper presents the speed control methodology by varying armature. Dc motor control using chopper a thesis submitted in partial fulfillment of the requirements of the degeree of bachelor of technology in electrical engineering by amir faizy 10602053 shailendra kumar 10502060 under the guidance of prof. The fourquadrant chopper dc drive dc7 block represents a fourquadrant, dcsupplied, chopper or dcdc pwm converter drive for dc motors. Pdf chopper fed speed control of dc motor using pi controller. The seven dc drive models of the library, designated dc1 to dc7, are based on the dc brush motor in the electric drives library. The speed control loop outputs the reference armature current of the machine. Part 2 continues with a look at converter output impedance, fourquadrant operation, single and doubleconverter reversing drives and power factor and supply effects. Detailed analysis of dc choppers and an example of pmdc motor. In this project the mathematical model for the speed control of dc motor using mosfet based chopper is designed and tested through the matlabsimulink software. Development of high performance motor drives are very essential for industrial applications. Choppers circuits an overview sciencedirect topics. Chopper based speed control of dc motor krest technology.
Types of chopper circuits type a, type b, type c, type d. This paper presents the speed control methodology by varying armature voltage of the dc motor. The variable voltage to the armature of a dc motor for speed control can be obtained from a dc chopper which is a single stage dc to dc conversion device. The speed of separately excited dc motor can be controlled from below and up to rated speed using chopper as a converter. In type b or second quadrant chopper the load must always contain a dc source e. Dc chopper device has the advantages of high efficiency, flexibility in control, light weight, small size, quick response and regeneration down to very low speed. We shall use the same dc motor for which the parameters were calculated in the. It has two operating modes to represent a detailed or an averagevalue chopper. A guide to electric drives and dc motor control ohio. Design and implementation of four quadrant dc drive using chopper. Chopper drives using trc,separately excited dcm,current limit control in chopper. This paper presents a comprehensive analysis which predicts the performance of a thyristor chopper controlled dc series motor during regenerative braking operation.
Introduction of dc motor control using igbt chopper. Chopper control techniques chopper control methods. A high performance motor drive system must have good dynamic. This paper proposes a method to control the speed and direction control of a dc motor by using a four quadrant dc dc chopper. One of the popular methods of speed control of dc motor is using chopper. It connects source to load and disconnects the load from source at a fast speed. The controlled object includes a threephase thyristor converter and a separately excited dc motor.
The chopper drive based speed controlling method is superior in comparison to thyristor controlled bridge rectifier method as far as dc motor speed. Tuning the parameters of a pid controller is very important. Separately excited dc motor speed control using four. The chopper gives variable voltage to the armature of the motor for achieving desired speed. By doing this, a chopped load voltage is obtained from a constant dc supply of magnitude vs. A thyristor current source inverter is shown in the figure below. The input dc voltage can be increased stepup or decreased stepdown in output side so a dc chopper circuit can be considered as dc equivalent to an transformer.
What are the factors that limit highfrequency operation. The chopper firing circuit receives signal from controller and then chopper. The purpose of this experiment is to design and implement a closeloop speed control of a dc motor drive. Pdf chopper fed speed control of dc motor using pi. Dcdc converter, dc motor, model reference adaptive control, neural network. Step up dc choppers are used for regenerative braking of dc motors. Part 3 examines the operation of a standard dc drive system with speed and current control. The modeling of separately excited dc motor is done and the complete layout of dc drive mechanism is. Chopper fed current controlled dc motor drive using pid controller. Design of single closed loop control for chopper fed dc. Simulation of voltage and current in series circuit s. The pulsewidth modulation method of control of semiconductor devices can help in controlling the output voltage of dc drives in. Electric traction electric drives jeanmarc allenbach 4.
There is also a gain potentiometer associated with the speed amplifier. Fall 2005 ee595s electric drive systems 36 the plan continued achieving 14. Four quadrant chopper, igbt, dc motor, pwm, voltage regulator. Type b chopper or secondquadrant chopper chopper second quadrant. The speed below the base speed can be controlled by armature voltage control method. As in any electric motor, the dc brush motor consists of the stator fixed part and the rotor movable part. The dc motor is an attractive piece of equipment in many industrial applications requiring variable speed and load characteristics due to its ease of controllability. Here,the power semiconductor switches are scr thyristor,mosfet,igbt,this type of speed control is called wardleona rd drive. When the chopper is on, v 0 is zero but the load voltage e drives the current through the inductor l and the chopper, l stores the energy during the time t on of the chopper. Fourquadrant fullbridge choppers pwm controlled with bipolar voltage switching 1.
Jul 02, 2017 dc to dc chopper circuit operating principle. Fractional order pid controller design for speed control of chopper fed dc motor drive using artificial bee colony algorithm anguluri rajasekhar1, shantanu das2, and ajith abraham3,4 1department of electrical engineering, national institute of technologywarangal, 506004, india. The chopper block models a standard halfbridge one leg, two igbts or fullbridge two legs, four igbts converter model. Step down dc choppers are used to control the speed of dc motor. Four quadrant operation of chopper fed separately excited. Thus by combining armature and field control for speeds below and above rated. Pid controller based chopperfed dc motor drive using fuzzy logic. Braking choppers are automatically activated when the actual dc bus voltage exceeds a specified level depending on the nominal voltage of the variablefrequency drive. In this paper, a simplified speed control design of chopper fed direct current dc motor drive with single feedback control structure is proposed. Study of speed control of dc series motor using dc chopper. Half converter, semi converter, full converter and dual converter are some of the thyristor based circuits which are used. Four quadrant operation of chopper fed separately excited dc. For higher power, dc drives with ratings from 5 hp to 6,400 hp visit our control techniques dc drives page.
Pdf design and implementation of four quadrant dc drive. This is set, during commissioning of the drive, to get optimally damped response of the closed loop, i. The system consists of dc dc buck converter to drive the dc motor. Each operating mode has multiple instances depending on the dc motor drive type two. Chopper controlled dc drives electronics electronic. Design and implementation of pid controller for a two quadrant chopper fed dc motor drive rahul v. First, internalmodelcontrol imc is used to control speed without closed loop current control scheme. Based on this observation, in what follows it will be analyzed the one and twoquadrant choppers with an active load of rle type dc motor. Solid state speed control of dc motor the dc motor speed can be controlled through power semiconducto r switches. The converter output is applied to the armature controlled dc motor. Speed of the dc motor is controlled by controlling the armature voltage.
Speed control of dc motor using mosfet based chopper. Armature voltage is controlled using different single phase ac dc converter. The principle of speed control for dc motor separatelyexcited or shunt is derived from the basic emf equation of the motor. Chopper fed dc motor drives austin hughes 11112008 2. Converter chopper fed dc motor drive single phase fully controlled converter fed separately excited d. In electronics, a chopper circuit is used to refer to numerous types of electronic switching devices and circuits used in power control and signal applications. The basic principle behind dc motor speed control is that the output speed of dc motor can be varied by controlling armature voltage for speed below and up to rated speed keeping field voltage constant. Dc motor speed control using chopper engineersgarage. Introduction of dc motor control using igbt chopper, working of four quadrant chopper operation, block diagram for dc motor control using igbt chopper, circuit diagram for igbt chopper. Thyristor converter offers greater efficiency, faster response, lower maintenance, smaller size and smooth control. Developments of high performance motor drives are very. A chopper is a high speed onoff semiconductor switch which connects source to load and disconnects the load from source at a fast speed.
The nema 4x ip65 drives are housed in a rugged diecast aluminum enclosure with a hinged cover. Speed control of dc motor using chopper presented by. Fig 6 a output voltage b output current c speed of dc motor for constant torque 15. The matlab simulation is used to compare the performance of chopper circuit. Dc choppers applications in dc motor drives and renewable. A chopper is a high speed onoff semiconductor switch. Matlab closed loop control of chopper fed dc motor youtube.
Separately excited dc motor speed control using four quadrant chopper rishabh abhinav, jaya masand, piyush vidyarthi, gunja kumari, neha gupta abstract the speed of separately excited dc motor can be controlled from below and up to rated speed using chopper as a converter. The power electronic circuit which converts directly from dc to dc is called dc to dc converter or dc chopper. Dc motors are also used in portable sewing machine, drill machine etc, in which speed control of motor is provided for different operation. Chopper controlled dc drives courtesy nirav mehta sir.
Matlab simulation on speed control of four quadrant dc. Conclusion the speed of a dc motor has been successfully controlled by using chopper as converter and proportionalintegral type speed and current controller based on closed loop model of dc motor. To a lesser extent, field control can be used for speed control but it is not widely used except for. Variable dc motor speed control penta power kbmd249d duration. Speed control of dc motor using chopper slideshare. A guide to electric drives and dc motor control an electric drive is an electromechanical system that employs an electric motor as the prime mover instead of a diesel engine, steam or gas turbines, hydraulics, etc. Choppers are widely used in trolley cars, battery operated vehicles, traction motor control, control of large number of dc motors, etc. The speed control strategies of dc motor plays an important role in the drive performance. Keywords dc motor, speed control, dc chopper, separately excited dc motor and current. Introduction the dc chopper is a dc to dc power electronic converter pec with forced commutation. Selfcommutated devices directly on or off devices via gate like mosfet, igbt, power transistors, gto and igct are used for making choppers because they can be commutated by low power control signal and do not need commutation circuit. Apr 11, 2017 speed control of dc motor using chopper 1.
The fourquadrant chopper dc drive block uses these blocks from the electric drivesfundamental drive blocks library. We have discussed about the basics of chopper in our previous posts. It is nothing but a high speed switch which connects and disconnects the load from source at a high rate to get variable or chopped voltage at the output. The motor drive shown is a speed controlled system. Dc drive, choppers, psim, simulation, power acceleration control. Hence the fopid controller is a sum of fractional operators along with controller gains. They are available in wide range of different power ratings, from very small motors as used in hard disk drives to large motors in electric vehicles. The small signal model for the chopperfed dc drive is given by.
It may further be noted that controlled rectifier will be used when supply is ac and chopper will be used when supply is dc. Nikhil chowdhary akansha 1473720006 department of electrical engineering rajkiya engineering college ambedkar nagar224122u. Pin diagram of lm324 lm324 combine the four opamp ic ie. Chapter 6 chopper controlled dc brush motor drives 6. Moreover, the dc motor drives supplied from a dc source. Design and implementation of pid controller for a two. The dc motor may be a dc series motor or a dc separately excited motor or a pmdc motor. A simple chopper fed dc motor drive is shown in fig.
Speed control of dcdc converter fed dc motor using. Digital control of chopper fed dc motor drive summary this thesis is concerned with a variablespeed dc drive system, based on the armature control of a separatelyexcited dc motor driven by a fourquadrant chopper. A 5hp dc motor is to he driven from a chopper for two applications. Bldc motors are driven by dc voltage and commutation is done electronically with the help of solid state switches. The use of speed controller is to take an signal sample of speed and to bring the motor to that desired speed.
Matlabsimulink in drives and power electronics practice 4. Pdf regenerative braking performance analysis of a. An approach to torque control of dc electric drives is discussed in this paper. Fourquadrant choppers are applied in drives in which regenerative breaking of dc motors is desired, for example, transportation systems with frequent stops. Implement dc chopper model for dc motor drives simulink. Performance study of power control method for chopper fed. The chopper gives variable voltage to the armature of the motor for achieving desired speed using proportional integral pi controller. Each operating mode has multiple instances depending on the dc motor drive type two or fourquadrant operation.
Experiment 5 dc motor speed control walter scott, jr. Dc motors are used extensively in adjustable speed drives and position control applications. What are the types of control strategies in dc chopper. Pdf an approach to torque control of dc motor drives. Pdf thyristor based speed control techniques of dc motor.
A variety of optional accessories are also available to meet the most demanding applications. Pdf closed loop speed control of chopper fed dc motor for. Discuss the power device to be selected for each of the applications. This drive features closedloop speed control with fourquadrant operation. Everywhere dc motors are used in large applications, the use of drives are very necessary for the smooth running and operating of these motors. Dc sources to supply dc choppers are batteries or diode. The speed of the separately excited dc motor can be controlled from below and above the rated speed by using buck converter. In this post let us see about various control techniques for chopper circuits. The armature voltage is controlled by a semiconverter or fullconverter and the field. So what is meant by control strategies or techniques of chopper circuit. Mehta power electronics engineering department, vishwakarma government engineering college, chandkheda 382424. Essentially, a chopper is an electronic switch that is used to interrupt one signal under the control of another.
Pdf in this paper present four quadrant speed control model is designed by using chopper. Compare a fourquadrant chopper and a phase controlled converter fed from a. The dc motor drives are used mainly for good speed regulation, frequent starting, braking and reversing. The pulsewidth modulation method of control of semiconductor devices can help in controlling the output voltage of dc drives in turn controlling the speed for a wide range. Chopper is a device that gives variable dc output from applied fixed dc input. Closed loop control of chopper fed dc motor control youtube. The speed control of dc motor for different applications is very important. At the same time the dc motor drive is less complex compare to ac motor drives. Fractional order pid controller design for speed control of. Chopper fed current controlled dc motor drive using pid.
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