Pdf microcontroller based dc motor speed control using. Modeling of dc motor the most common device used as an actuator in mechanical control is the dc motor. The time until a shortcircuit condition appears differs per motor type. Experiment 7 series dc motor i objectives to determine the torquespeed characteristic curve.
A dc motor is any of a class of rotary electrical motors that converts direct current electrical. Motor load torque, speed, position sensor strain gauge, potentiometer, tachometer, encoder linear, pwm convert discrete signal to analog voltage da converter pulse width modulation pwm amplify the analog signal power supply ampli er types of power ampli ers linear vs. Dc motors although ac motors are used in most of the cases, dc motors have many applications and used for multipurpose applications. Lesson 3 understanding and using dc motor specifications. Use sensor for feedback desired speed actual speed test computation motor encoder measurement. Adafruit drv8871 brushed dc motor driver breakout created by lady ada last updated on 20180822 03. The torque generated by the motor, and its speed of rotation, are dependent on each other. Dualaxis current control of brushed dc motors application. Dualaxis current control of brushed dc motors application report.
Now you will know about commutation in dc machine or generator. The paper deals with experimental method of dc motor friction. Dc motors are rarely utilized in normal applications as a result of all electrical supply firms furnish electrical energy but, for special applications like in steel mills, mines and electric traction, its advantageous to convert ac into dc so as to use dc motors. A good material for the poles of a pmdc motor should have the apposite of the above. What is common to all the members of this family is that the basic physical process involved in their operation is the conversion. Dwg and dxf files can only be opened and edited by cad programs. The dc motor should begin spinning and the scopes on the vi should appear similarity as shown in figure 7. Induced voltage opposes applied voltage and limits current. A majority of electric motors used are brush type dc motor, followed by ac induction motors and brushless dc bldc motors. The innovative mechanical design of the dmi product is extremely versatile, which means dmi motors can be tailored to meet specific performance requirements. Brushed dc motors, despite their mechanical complexity, are governed by only a few forces. Torque exerted by the motor, when a multiple segments commutator is used. The actual force in a generator is multiplied by the number of conductors in the armature. Fundamentals of direct current circuits ced engineering.
In this experiment the mechanical characteristics b and j will be determined. Because of the low profile design, this motor is also a simple drop in replacement. A direct current dc motor is an electric machine that converts electrical energy to mechanical energy. This lab allowed us to further investigate the characteristics of the various dc motor speed control schemes. The figure below shows the schematic diagram of 2pole lapwound generator. Similar to dc machines, synchronous machines can provide torque when.
The operating principle of a dc motor is based on the interaction between the magnetic field of a rotating armature and the magnetic field of a fixed stator. Introduction direct current dc motors comprise one of the most common types of actuator designed into electromechanical systems. Once you have collected a step response, click on the stop button to stop running the vi. As the north pole of the armature is attracted to the south pole of the stator and viceversa, a force is produced on the armature, causing it to turn. Frames the standard specifies a horizon tal frame split so that the armature can be lifted straight up and out. You can tension the belt by pivoting the motor plate about the bolt and relying on the bolt friction to hold the motor in position. Principles of operation the construction of a simple bdc motor is shown in figure 1. Bldc motors produce more output power per frame size than brushed dc motors and induction motors. Dc motor friction identification is by means of experimental method done using newtons mechanics. The system structure of a dc motor is depicted in figure22, including the. Dc motor applications tecowestinghouse motor company dc motors are ideally suited to a multitude of industrial and marine applications in which high torque and variable speed are required. Hbridge for driving a bdc motor in both directions. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext.
They are a very straightforward and inexpensive means of creating motion or forces. Motor power rated voltage mounting ventilation dimensions type watt speed vdc mm torque nm 3000 2000 b3 b5 b14 natural fan diameter lenght rpm rpm cooled penta 1s 45 0. Dc motor introduction, principle and working my tech info. Speed control of a dc motor using pulsewidth modulation. The dc motor contains a stator and a rotor, the latter being more commonly called an armature. There are two types of controls which were made in order to control the speed as well as the current. Dc motor specifications gear box construction and features protection against overload and locked rotor when the rotor is locked and voltage is applied to the motor terminals, the temperature of the motor windings will rise and eventually shortcircuit. Dc motor introduction, principle and working introduction. E x p e r i m e n t 3 characterization of dc motor.
Lathes, drills, boring mills, shapers, spinning, and weaving machines series motor. Dc motor brochure singles tecowestinghouse motor company. They are unique, however, both in construction and in the way they manipulate their torqueproducing fields. Dc motor speed control using microprocessor technique. By varying the pulse width duty cycle, we are able to create variable speed motor. Dmi dc motor makes it an ideal choice for upgrading existing dc motor installations. The commutation in dc machine or more specifically commutation in dc generator is the process in which generated alternating current in the armature winding of a dc machine is converted into direct current after going through the commutator and the stationary brushes. The macros are defined in the header files, and the macro definitions can be changed in the. We send in a pulse width modulated signal from port t3 which will drive the motor. The dc motor is very difficult to contr ol unlike the stepper motor, which can be controlled by giving the appropriate control word. Dc motor speed control using microprocessor technique intoduction.
In this particular case, notice that the ux owing in the coil is given by equation 3 substituting with the angle t of the motor and a with the area of the internal surface of the coil. Use engineering methods and mathematical models in an effort to most closely match dc. Dc brush motors, dc permanentmagnet pm motors, and dc universal motors. Anatomy of a bldc figure 1 is a simplified illustration of bldc motor construction. This motor handbook was created by infineon technologies ag together with. Other motor types compared to brushed dc motors and induction motors, bldc motors have many advantages and few disadvantages. Another name for a coil or loop of wire inductors oppose the change in current. The purpose is that your special oem customers should have a minimum of work for converting this design for implementing the dmi im 1001 is for foot mounting and im 2001 is for flange mounting. Introduction a series dc motor is a motor whose filed windings consists of a relatively few turns connected in series with the armature circuit. The performance of the machines depends on the positioning systems. Brushed dc motor fundamentals microchip technology. These applications include ship propulsion, mine hoists and steel rolling mills.
Learners study the interaction between the conductors of the stator and the armature inside a dc motor, which causes the shaft to rotate. The development of such a block diagram for the dc machine is shown in figure 4. With no armature current, there is no magnetic motor reaction. Whence, computing the derivative in equation 12, the back electromotive. According to the most common industry naming conventions of today, there are three dc motor subtypes. When q2 and q3 are on, the motor moves in the opposite direction. The curve for the output power of the motor is deduced from the graph of torque versus speed. As the armature current increases, the reaction of each armature conductor against rotation increases. To find out how to reverse the direction of rotation of a series dc motor.
Speed control of a dc motor using pulsewidth modulation author. Use their understanding of newtons laws of motion, torque and rotational speed to compute the performance requirements of a dc motor system. Motor property 1 torque is proportional to current question. The characteristics of a shunt motor reveal that it is an approximately constant speed motor. Precision positioning systems are fundamental components in industrial machines such as machine tools, measuring machines and semiconductor manufacturing systems. At first the basic static friction models are introduced and linear mathematical model of dc motor is established. The dcmct modeling vi, shown in figure 2 and figure 3, runs the dc motor in openloop and plots the corresponding speed and input voltage responses.
Other motors were also tested to assure that the code was generally useful. Pdf microcontroller based dc motor speed control using pwm. Because of the low profile design, this motor is also a simple dropin replacement. Therefore, the force required to turn the armature is low. The stator contains one or more windings per pole, all of which are designed to carry direct current, th ereby setting up a magnetic field. Armature controlled dcmotor next, note that the angular speed. The functional requirements and design parameters of a motor system can be determined early in. Its operation is based on the principle that when a current carrying conductor is placed in a. Brushless motors rely on semiconductor switches to turn stator windings on and off at. The aim of the paper is determining of suitable way of dc motor friction modeling. This document also examines control principles using hall sensors for both singlephase and threephase. A brushless motor is constructed with a permanent magnet rotor and wire wound stator poles. When q1 and q4 are on, the motor moves one direction. Dc motor principle a machine that converts dc power into mechanical energy is known as dc motor.
For example, the control of a rotary inverted pendulum requires a dc motor to drive the arm and the pendulum as shown in figure 21. This system demonstrates current control of a brushed dc motor. Benefits of using c2000 controllers for digital motor control dmc. In this lab experiment, the dc motor speed control was studied. First, a look at an incredibly simpli ed motor, a square loop in a magnetic eld, as shown in figure 1. Motor control rss lecture 3 monday, 7 feb 2011 prof.
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. We used the fact that the speed of a dc motor is directly proportional to the voltage applied across its windings. Brushless dc motor control with hall sensors using. Here the dc motor is controlled by the microprocessor 8085. Dec 07, 2014 dc motor introduction, principle and working introduction. Understanding and using dc motor specifications gears. The model of output voltage control of the switchmode dc converter was discussed in experiment 2 and the same will be used. From the main problem, the dynamic equations in the laplace domain and the openloop transfer function of the dc motor are the following. In general, a dc motor,s stalling torque is equal to its starting torque. The armature and its windings are located in the path of this magnetic field, and. The motor is normally supplied with a tall pulley but you may need a shorter pulley 10mm less in height please contact us if this is case.
Brushless motors require less maintenance, so they have a longer life compared with brushed dc motors. As shown in figure 3, when a pulley with radius r is attached to the motor and force of f is applied to the pulley,s circumference, the torque generated, tl, can be derived by multiplying f and r f. This vi can be used to take speed and voltage measurements of the responses, as illustrated in figure 3, and runs a simulation of the dc motor in parallel. Brushless dc motor fundamentals application note monolithic. This application note will discuss how a bdc motor works, how to drive a bdc motor, and how a drive circuit can be interfaced to a pic microcontroller. A brushed dc motor is made up of 4 basic components. Brushed dc bdc motors are inexpensive, easy to drive, and are readily available in all sizes and shapes.
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