The control principles of various dc and ac motors using solid. A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric or hydrogen vehicles, elevators or electric multiple unit traction motors are used in electrically powered rail vehicles electric multiple units and other electric vehicles including electric milk floats, elevators, roller coasters, conveyors, and trolleybuses, as well as vehicles with. The mechanical power produced by the motor can be used to drive a mechanical load e. For a dc motor, the efficiency is the electrical output power divided by the mechanical. Fall 2005 ee595s electric drive systems 36 the plan continued achieving 14. Therefore, replacement drives must be carefully selected so they have re. Dc drive is basically a dc motor speed control system that supplies the voltage to the motor to operate at desired speed. It consists of an electric motor motors, a transfer mechanism, an electrical energy converter, and a control system. Chopper controlled dc drives single and multiquadrant converters, motoring and braking operations week 4.
Some of the more involved mathematical derivations are contained in appendices to this note. Unlike a brushed dc motor, the commutation of a bldc motor is controlled electronically. C motors by dual converters closed loop operation of dc motor block diagram only unit iv. Power electronics have eased the concept of power control. To do the modeling and simulation of dc motor, the following steps are followed. Direct current machines dc machine construction the rotor iron core is mounted on the shaft. Fundamentals of electrical drive controls josko deur and danijel pavkovic university of zagreb, faculty of mechanical engineering and naval architecture, i. The content is first elaborated theoretically, and then consolidated in. In terms of construction a brushless dc motor is similar to an ac synchronous motor fed from the frequency converter. What is common to all the members of this family is that the basic physical process involved in their operation is the conversion. Representation of a motor in terms of an ideal motor. Lecture 16 dc motor speed control introduction youtube. First, the drive input is the ac power entering the drive from.
The content here does not translate well to singlephase motors. We have the choice of using either a separately excited motor or a series motor. Electrical brushless dc motor introduction, working and. Solid state speed control of dc motor the dc motor speed can be controlled through power semiconducto r switches. Kb standard offtheshelf dc drives provide variable speed for dc motors from subfractional to 5 horsepower. Four quadrant operation of dc motor four quadrant operation of any drives or dc motor means that the machine operates in four quadrants. This is done in the dc motor by a pm stator and a wound armature or rotor. If for a drive two or more even number of identical motors are used as in traction, the. Pdf power electronics and drives used in automotive. If the motor is stationary and a voltage va is applied, a current ia flows which causes the motor to rotate.
Earlier, the variable dc voltage for the speed control of an industrial dc motor was generated by a dc generator. They are forward braking, forward motoring, reverse motoring and reverse braking. Other members of the family are the directcurrent dc motor or generator, the induction motor or generator, and a number of derivatives of all these three. Dc motor drives 2007 ppt electric motor control theory. Here you can download free lecture notes of power semiconductor drives pdf notes psd pdf notes materials with multiple files linkspsd notes pdf. Direct current machines may be magnetized in two different ways. The electric motor is the core component of an electrical drive that converts electrical energy directed by power processor into mechanical energy that drives the load. Mechanical energy what is an electric motor an electric motor is a device converting electrical energy into mechanical energy usually a torque. The block diagram of the electrical drive is shown in the figure below. Then we will discuss how the machine geometry can be used to estimate both the elementary rating parameters and the parameters used to make more detailed estimates of the machine performance.
Variablespeed drives can also run a motor in specialized patterns to further minimize mechanical and electrical stress. May 18, 2008 lecture series on industrial automation and control by prof. Permanent magnet synchronous motor is used for medium power drives. The end of the coils are bent and tied together to assure mechanical strength. By varying the resistance in the armature circuit rheostatic control 2. Most mechanical adjustablespeed drives and motorgenerator types of electrical adjustablespeed drives inherently offer regenerative capability. Dc motor principle a machine that converts dc power into mechanical energy is known as dc motor. Advanced control techniques are applied to optimize the performance of ac motor drives. The armature and field resistances are 1 ohm and 150 ohm respectively. The dc voltage is fed into the dc bus circuit, which filters the pulsating voltage. Please find the full notes on electrical machines and drives. The propulsion systems of electric, hybrid electric and plugin hybrid. Nptel syllabus industrial drives power electronics.
The variable dc voltage is controlled by varying the on and offtimes of a converter. Enclosure types include chassis ip20, nema 1 ip50 and nema 4x ip65. In other words a rectifier circuit is placed in the system. Gopakumar, centre for electronics design and technology, iisc bangalore. Acs50 sizing up the consumer the new variablespeed microdrive targets new markets like the consumer industry. It also refers to a subject of research in electronic and electrical engineering which deals with the design, control, computation and integration of nonlinear, timevarying energyprocessing electronic systems with fast dynamics. Notes for an introductory course on electrical machines. Dmi a milestone in the development of dc motors abbs dmi motor range has many advantages including high power, a wide speed range and small dimensions. The book covers the following topics three phase circuits and power magnetics transformers concept of electrical machiners dc motors three phase windings induction machines.
Different semiconductor devices can be studied applications. Here are the different test points in a typical threephase motor drive system figure 1. They are generally more expensive than induction motor dri ves,but the advantages is that the efficiency is higher,which is tends to lower the life cycle cost. A servo motor is basically a dc motor in some special cases it is ac motor along with some other special purpose components that make a dc motor a servo. A brushless dc motor consists of a rotor in form of a permanent magnet and stator in form of polyphase armature windings. All we need to do is to keep daxis stator current constant. Instead, brushless dc motors dc motor with a semiconductor commutator are used. Hello and welcome to this lecture on advance electric drives. Analysis of power semiconductor switched circuits with r, l, rl, rc loads, d. The bc series starts at fractional and runs through 5 horsepower for single phase 115 and 230 vac applications. Dc motor, the ac induction motor, and the ac synchronous motor.
Before enlisting the practical applications of the drives used for. Electrical engineering advanced electric drives nptel. The motor is a permanent magnet type and can be represented in idealized form as in figure 5, where ra is the armature resistance and t1, t2 are the actual motor terminals. The requirement of an electrical load is determined regarding speed and torque. The dc motor drive is a type of amplifier or power modulator that integrate between the controller and a dc motor. Then we will discuss how the machine geometry can be used to. Third, the ac network feeds the electric drives and a supply converter rectifies the voltage of the motor. Advanced electric drives video course electrical engineering nptel. Review of characteristics of different types of dc and ac. 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. Torque speed characteristics of converterfed dc drives week 3. Although dc motors possess good control characteristics and ruggedness, their performance and applications in wider areas is inhibited due to sparking and. By varying the applied voltage voltage control solid state speed control of dc motor the dc motor speed can be controlled through power semiconducto r. Whether you are looking to build new or retrofit an existing installation, our portfolio of stateoftheart dc drives gives you design flexibility and the proven dependable performance expected from an abb drive.
Current in the dc motor is automatically switched to different windings by means of a commutator and brushes to create continuous motion. Power electronics signifies the word power electronics and control or we can say the electronic that deal with power equipment for power control. Other members of the family are the direct current dc motor or generator, the induction motor or generator, and a number of derivatives of all these three. The control of electric motor drives requires control of electric power. To rotate the bldc motor, the stator windings should be energized in a sequence. As of today we have 75,612,618 ebooks for you to download for free. It takes the low current and then converts it into a high current which is appropriate for the motor. It is assumed that the students have prior exposure to electrical machines and power electronics. Ac drives dc drives variable frequency speed drives vfd. Chopper controlled dc drives single and multiquadrant converters, motoring and braking operations. The dc motor drive also provides the high current torque, 400 % more than the rated continuous torque. With more than 50 years of experience in variable speed drive business, driveswarehouse stocks a large selection of ac drives, dc drives, variable frequency drives vfd, variable speed drives, adjustable speed drives, adjustable frequency drives, combo ac motor and drive combination and dc motor and drive combination in a wide range of. Power electronics is the application of solidstate electronics to the control and conversion of electric power.
Closed loop operation of dc motor block diagram only. Excitation sequences for different drive modes figure 7. They are designed for dc motor applications and retrofits up to 6000 hp 4000 kw. Its operation is based on the principle that when a current carrying conductor is placed in a. The inverter unit then connects each motor phase either to the negative or the positive dc bus according to a certain order. Unlike common dc motor types, power is delivered to windings in the stator case rather than the rotor. In this lesson we discuss speed and position control. Nptel provides elearning through online web and video courses various streams. In a servo unit, you will find a small dc motor, a potentiometer, gear arrangement and an intelligent circuitry. This document is a brief introduction to the design evaluation of permanent magnet motors, with an eye toward servo and drive applications. Lecture notes on power electronics veer surendra sai.
Applications advantages and numerical problems closed loop control operation of synchronous motor drives block diagram only. Home download center electrical engineering books and technical guides siemens basics of energy and automation guides basics of dc drives controlling a dc motor a thyristor bridge is a technique commonly used to control the speed of a dc motor by varying the dc voltage. Motor operation dc motors are built the same way as generators armature of a motor connected to a dc power supply current flows through the armature winding armature is within a magnetic field a force is exerted on the windings the force causes a torque on the shaft the shaft rotates f b l i. Lecture series on industrial automation and control by prof. The design of motor drive for brushless dc motor intechopen. This greatly simplifies mechanical design as power does not have to be delivered to a moving part, but it complicates the electrical design as some sort of switching system needs. This conversion is usually obtained through the generation of a.
It differs from conventional dc motor in such that it doesnt contains brushes and the commutation is done using electrically, using a electronic drive to feed the stator windings. Pdf this chapter deals with power electronics and drives used in electric vehicles ev. Advanced electric drives video course course outline the first course on electric drives usually introduces the concept of control of electric motors for various types of mechanical loads. A motor drive capable of operating in both directions of rotation and of producing both motoring and regeneration is called. The motor can be dc motor or ac motor depends on the type of load. It consists of several copper segments, separated by insulation. Our dc solutions can meet the needs of a wide range of demanding applications.
For servo drive applications, dc motors are still used, although they are also being replaced by bldc motors. In this lesson well examine motor drives, power electronics devices that vary the speed and torque of a motor under its direction by varying the supplied voltage magnitude and frequency. It is important to know the rotor position in order to understand which winding will be energized. Four quadrant operation of dc drives introduction to four quadrant operation motoring operations, electric braking plugging, dynamic and regenerative braking operations. A motor operates in two modes motoring and braking. The motor draws a line current of 10 amp at the given load. Unit 1 characteristics of electrical drives speed torque characteristics of various types of loads and drives motors. For example the available power source is ac and the motor is dc series motor, then the converter converts ac into dc. Generally,a vector controlled induction motor drive can operate as a separtly excited dc motor drive. The dc motor drives are used mainly for good speed regulation, frequent starting, braking and reversing. Everywhere dc motors are used in large applications, the use of drives are very necessary for the smooth running and operating of these motors. Download nptel handwritten notes of transformer download nptel handwritten. What is common to all the members of this family is that the basic. Therefore, this chapter will focus on the design and implementation of a motor drive as well as its realization of control algorithm.
Apr 11, 20 the function of converters is to convert the electric waveform of the power source to a waveform that the motor can use. Here,the power semiconductor switches are scr thyristor,mosfet,igbt,this type of speed control is called wardleona rd drive. The motor which suited the capabilities of the load is chosen for the load drive. Literature direct current motors and drives 150 3000hp.
Jan 07, 2017 in this lesson well examine motor drives, power electronics devices that vary the speed and torque of a motor under its direction by varying the supplied voltage magnitude and frequency. The simple understanding of concepts and design of dc. Brushless dc motor bldc and permanent magnet ac synchronous motors drives have many advantages such as high efficiency, small size, less rotor losses, and fast torque response over the induction motor drives. Power semiconductor drives pdf notes psd pdf notes. Behind the standard open loop drive, stands several other types of drive products. Industrial drives power electronics nptel online videos.
Finally, the motor and drive train itself note that this article is about troubleshooting threephase motors and drives. A model of a dc motor using the generalized equation in matlab is obtained and the time domain and frequency domain responses for both step, impulse and bode plot is respectively discussed. Initially, the dynamic models of the dc and ac motors are developed that will be useful in understanding the dynamic control. For the latter two technologies, we consider the case of threephase power, which is generally preferred over singlephase because of much higher power density. Electrical engineering industrial drives power electronics nptel. Dc machines 1 dc machines transformsmechanicalenergyintoelectric energywithdc voltage and current dc generatoror dynamo, or conversely dc motor. Servomechanism theory and working principle of servo motor. Since majority of modern drives are ac motor drives, the course centers around the control of ac motor drives. Ac drives instead gradually ramp the motor up to operating speed to lessen mechanical and electrical stress, reducing maintenance and repair costs, and extending the life of the motor and the driven equipment. In the first course, mainly the dc motor control both steady state and dynamic, and steady state torque and speed control of ac motors are emphasized.
Open loop vhz ac drives are the most common drive in use today, with up to 70% use, according to some surveys. Dc motors although ac motors are used in most of the cases, dc motors have many applications and used for multipurpose applications. How to troubleshoot motors and drives, starting at the inputs. Operation of induction motor with unbalanced source voltages. Ac dc converter, dc dc converter, dc ac converter module 3 dc to dc converters9l. Load torques which have the potential to drive the motor under equilibrium conditions are called active load torques. It matches the motor and power converter to meet the load requirements. Application characteristics of permanent magnet synchronous. Application characteristics of permanent magnet synchronous and brushless dc motors for servo drives pragasen pillay, member, ieee, and ramu krishnan, member, ieee abstractthe permanent magnet synchronous motor pmsm and the brushless dc motor bdcm have many simi larities. When the stator windings are energized with dc current the. Electrical drives, control, modeling, dc motor, permanentmagnet synchronous motor. The switched reluctance motor srm is a type of stepper motor, an electric motor that runs by reluctance torque.
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