Dc chopper conver ts fixed dc into variable dc voltage. Assuming the electric eld to be zero this is the case of a dc motor, with reference to the quantity of charge dq found. Jul 11, 2019 speed control of a dc motor is either done manually by the operator or by means of an automatic control device. Download nptel handwritten notes of dc machine download nptel handwritten notes of induction machine. In the tutorial dc motor speed control in labview, i will explain you a complete step by step procedure to control the clockwise and counter clockwise direction of the dc motor as well as accelerating and deacelerating it with the help of the buttons on the gui created in ni labview using serial communication between arduino and ni labview. Introduction, characteristics, adjustible speed drives 35. Use sensor for feedback desired speed actual speed test computation motor encoder measurement. Modern control problems lecture 6 dc motor speed control lecture 7 system modelling, analogy lecture 8 causes of. Fall 2005 ee595s electric drive systems 30 overview of strategies voltsperhertz control. Introduction, dc dc converters, adjustible speed drives 34. In this report, we have implemented a dc motor speed control system. Conclusion in this lab experiment the dc motor speed. Speed control of bldc motor is essential for making the motor work at desired rate.
When motor works in normal mode or runs below rated speed, input voltage of armature is changed through pwm model. The idea of a speed control system is to maintain the speed of the motor at the desired value under various condition. Target motor theory 3phase ac motor control with vhz speed closed loop, rev. This video lecture, part of the series industrial drives. These notes has been made by me after watching nptel lectures given by dr. Nptel video lecture topic list created by linuxpert systems. For controller design two methods are used, namely frequency shaping method and pwm control. When switches 1 and 4 are closed and 2 and 3 are open, voltage. Speed of a dc shunt motor can be varied very easily with good efficiency, but in case of induction motors, speed reduction is accompanied by a corresponding loss of efficiency and poor power factor. Dc motor speed control is one of the most useful features of the motor.
Dc motor speed control in labview the engineering projects. To control the direction, the polarity of the motor is reversed. Speed control methods of dc motor speed control of shunt motor 1. Lecture series on basic electrical technology by prof. Speed control of bldc motor with pi controller and pwm. Stepper motors stepper motor an electromagnetic actuator.
Dc motor with speed and current closed loops, driven by. Pdf speed control of dc motor by using pwm technique. What are the best ways to control the speed of dc motor. For this example, we will assume that the input of. There are two ways of speed control for a dc motor, field control in this method, the eld current or current through stator is varied to control the speed of. K e b o where, kconstant this shows the speed of a dc motor is directly proportional to the back emf and inversely proportional to the flux per pole. Speed control of a dc motor is either done manually by the operator or by means of an automatic control device. The typical 3phase inverter is illustrated in figure 32.
Apr 24, 2017 in the tutorial dc motor speed control in labview, i will explain you a complete step by step procedure to control the clockwise and counter clockwise direction of the dc motor as well as accelerating and deacelerating it with the help of the buttons on the gui created in ni labview using serial communication between arduino and ni labview. This lab allowed us to further investigate the characteristics of the various dc motor speed control schemes. He has 8 years of experience in customer support, operations and administration. Agashe, department of electrical engineering,iit bombay. The aim is to establish relationship between the speed of dc motor and the load torque at different voltages as well as investigating the performance of closedloop systems when different voltages are applied to the. In order to measure the time response of a dc motor it is necessary to obtain transfer function of the dc motor. This is different to speed regulation where the speed is trying to be maintained or regulated against the natural change in speed due to a change in the load on the shaft. In fact, fine speed control is one of the reasons for the strong competitive position of d. The equation shows that the speed is dependent on the supply voltage v, the circuit resistance ra, and the field flux. Speed control of dc motor the speed of a dc motor is given by i flux control. If a company wanted to have reliable production, it should stick with known, proven. Speed control of dc motors the speed of a dc motor is given by the relationship. The arrangement of this system is as shown in the figure at right.
By controlling the speed of the motor, you can vary the speed of the motor according to the requirements and can get the required operation. Speed control of dc motor the speed of a dc motor is given by i. Pdf the purpose of this project was to control the angular rate of the load shaft position of a dc motor by varying the applied input voltage. Speed of a dc motor back emf e b of a dc motor is nothing but the induced emf in armature conductors due to rotation of the armature in magnetic field. Lecture 11 automatic control of dc motor lecture 12 proportional control lecture nonunity feedback lecture 14 signalflow graph lecture 15 masons gain formula lecture 16 signalflow graph for dc motor control lecture 17 steadystate calculations lecture 18 differential equation model and laplace transformation model.
In an open loop control, the only components in the system. Over 30 years ago, ac drives were considered new technology. Speed of a brushless dc motor can be controlled by controlling the input dc voltage. Modelling and simulation of armaturecontrolled direct. Fall 2005 ee595s electric drive systems 29 transient performance of constant. This mean that a digital signal is used to drive the motor and every time it receives a digital pulse it rotates a specific number of degrees in rotation. An induction motor is practically a constant speed motor, that means, for the entire loading range, change in speed of the motor is quite small. In this lab experiment, the dc motor speed control was studied. If you have watched this lecture and know what it is about, particularly what electrical engineering topics are discussed, please help us by commenting on this video with your suggested description and tit. In practice, the dc motor is a nonlinear device and its speed varies because of change in load demand, disturbances,etc. Characteristics of generators and parallel operation of generators iv.
In this project paper microcontroller based system to control speed of induction motor is developed using pulse width modulation technique 2. The electric equivalent circuit of the armature and the freebody diagram of the rotor are shown in the following figure. Lecture 16 dc motor speed control introduction youtube. M1 may be any ac motor or dc motor with constant speed. Dec 11, 2016 the arrangement of this system is as shown in the figure at right.
Gopakumar, does not currently have a detailed description and video lecture title. If you have watched this lecture and know what it is about, particularly what electrical engineering topics are discussed, please help us by commenting on this video with your suggested description and title. Apr 01, 2008 lecture series on basic electrical technology by prof. To study the methods of controlling the speed of separately excited dc motor. It is possible, however, to control dc motor speed without tachometer feedback. Time response analysis of dc motor using armature control. The paper deals with design of control for dc motor and analysis with focus on speed control.
Various types of losses that occur in dc machines and. Dc machines 1 dc machines transformsmechanicalenergyintoelectric energywithdc voltage and currentdc generatoror dynamo, or converselydc motor. Motor principles, adjustible speed and servo drives 36. Dc motor with speed and current closed loops, driven by etpu on mcf523x, rev. To some, motor speed control is somewhat of a mystical science, a science that causes motors and machines to sometimes operate in unexpected ways. Speed of a dc motor we know, back emf of a dc motor eb is the induced emf due to rotation of the armature in magnetic field.
Dc machine are the electromechanical energy conversion devices which converts either dc power to mechanical power or mechanical power to dc power. Tarun agarwal is the chief customer support officer at edgefx technologies pvt ltd. We cant imagine our life without speed control of a motor, because nowadays all moving equipment works with the help of motor, it may be a ac motor,dc motor or a servomotor. The inverter converts dc power to ac power at required frequency and amplitude. In this paper speed control of the dc motor by armature control method is proposed. Dc machines 1 dc machines transformsmechanicalenergyintoelectric energywithdc voltage and current dc generatoror dynamo, or conversely dc motor. Umanand, principal research scientist, power electronics group, cedt, iisc bangalore. Transfer function is obtained by conducting the speed control test on the dc shunt motor 2. Operating principles of vector control generally,a vector controlled induction motor drive can operate as a separtly excited dc motor drive. In practice variation of the three factors is used for speed control. A common actuator in control systems is the dc motor.
The ampl itude of the appl ied voltage is adjusted using the pwm technique. Content speed of a dc motor speed control methods of dc motor speed control of shunt motor speed control of series motor 3. Apr 17, 2008 lecture series on power electronics by prof. In the dc motor, the current polarity is altered by in this paper we developed the mathematical model of the brushless dc motor and control the speed of the motor using pi controller. It is an incremental drive digital actuator and is driven in fixed angular steps. A brushless dc bldc motor construction is similar to the synchronous motor with permanent magnets on rotor. Gopakumar, centre for electronics design and technology, iisc bangalore. Mod01 lec32 lecture32speed control of dc shunt motors. Massachusetts institute of technology department of electrical engineering and computer science 6. Various types of losses that occur in dc machines and how to calculate efficiency vi. Get digimat digital media access terminal for highspeed video streaming of nptel and educational video courses in lan nptel video course electrical engineering power system dynamics and control. The phenomena of armature reaction and commutation iii. Veermata jijabai technological institute 25 speed control of dc motor by using pwm technique 1. Dc motor speed is often regulated with a closedloop speed controller using tachometer feedback figure 1.
For creating and simulating the mathematical model matlab program with simulink extension was used. Mathematical modeling of brushless dc motor and its speed. A voltage applied across a motors winding forces the motors rotor to turn. Sensorless bldc motor controlsometimes called sensorless trapezoidal control of bldc motorsuses back emf bemf for determining the location of the motors rotor the motors rotating part with respect to the motors stator the stationary part. To control the speed, the input voltage is varied using pulsewidth modulation. The electric motor speed is fixed when ac motor is connected to ac line.
It privides independent control of flux and troque,and the control characteristic is linearized. There are two types of controls which were made in order to control the speed as well as the current. Dc motor with speed and current closed loops, driven by etpu. It directly provides rotary motion and, coupled with wheels or drums and cables, can provide translational motion. The aim is to establish relationship between the speed of dc motor and the load torque at different voltages as well as investigating the performance of closedloop systems when different voltages are applied to the armature circuit of the motor when a constant voltage. What are the applications of speed control of a motor. To control a dc motor from a microcontroller, you use switching arrangement known as an h bridge. Methods for speed control of dc motors and applications of dc motors v. The pmdc consists of rotor or armature and a stator, which is a permanent magnet. Thus, the magnitude of e b can be given by emf equation of a dc generator. Fall 2005 ee595s electric drive systems 29 transient performance of constant slip controlled drive. Figure 2 shows an openloop type speed control circuit that drives a dc motor at a speed proportional to a control voltage, vin. By varying the dc voltage,the motor speed can be controlled. As induction motors are widely being used, their speed control may be required in many applications.
In the next section, different way of controller design will be discussed. Speed control of induction motor using pwm technique. The pulsewidthmodulation pwm has been widely used in the electronic and electrical systems including attitude control systems, adaptive control systems, signal processing, power control systems, and so forth. An ev with two input sources 1 joint initiative of iits and iisc funded by mhrd page 41 of 55 nptel electrical engineering introduction to hybrid and electric vehicles. Such a fine speed control is generally not possible with a. Nptel video lecture topic list created by linuxpert. The present course advanced electric drives focuses on the dynamic control of dc and ac motor from solid state converters for better torque and speed response. Firstly, mathematical model of dc motor was created.
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