To obtain the armature voltage vs armature current load curve of the generator. This simulates the conditions where user can use separately excited dc motor or a dc shunt motor without affecting the. To interpret the load characteristics of a dc shunt motor. As resistance increased, the value of the field current will reduce. Study of separatelyexcited dc shunt generator objectives 1. This paper discusses the speed and torque control of a shunt dc motor through matlab simulink simulations. Discussion a dc motor generator can run either as a motor or as a generator. Connect the shunt field of the dc motor generator, terminals 5 and 6, to the variable dc output of.
Title of the experiment page no 7 retardation test on dc shunt motor. Introduction to electrical power and machines eet2166. The 4 point starter doesnt have big different than 3 point start as we also use it with series wound dc motor, shunt wound dc motor and compound wound dc motor and it mainly has the same construction except for an additional terminaln which links the supply to the no voltage coil. In electrical terms, parallel is generally denoted as shunt. High voltages are present in this laboratory experiment.
Dec 29, 2015 because of their selfregulating speed capabilities, dc shunt motors are ideal for applications where precise speed control is required. Therefore the voltage drops i a r a will be negligible as compared to the external supply voltage v. To obtain the noload magnetization characteristics. Once the parameters are tuned, the model of the dcmotor will be replaced with the real motor. The dc generator as we know can be either separately excited or self excited in shunt. Mar 23, 2019 a series wound dc motor like in the case of shunt wound dc motor or compound wound dc motor falls under the category of selfexcited dc motors, and it gets its name from the fact that the field winding in this case is connected internally in series to the armature.
The objective of the dc machine lab is to expose the students to the operation of dc machines and give them. Feb 22, 2018 load test is performed on all motors for the common purpose of determining the efficiency of the motor. Lab5 the dc selfexcited shunt generator objective 0 to. Three digital multimeters, a set of sheathed banana cables and a power quality meter from the stockroom. Starting of dc motor 3 point starter, 4 point stater. Automatic speed controller of a dc motor using arduino. List of requirementsequipmentexperimental panel system unit w 1. The whole idea was to change the load of the motor, trying to maintain the speed of the motor, by controlling the duty cycle electronically. Shunt dc motor the shunt motor is probably the most common dc motor used in industry today. Dc motors although ac motors are used in most of the cases, dc motors have many applications and used for multipurpose applications. The variable speed drives, which can control the speed of a. View lab report lab21 from elet 64 at university of houston.
By decreasing the flux, the speed can be increased and vice versa. In a shunt motor, the field winding, as we ll as the armature winding, is connected in parallel shunt directly to the dc supply lines. Speed control of dc motor by using pwm technique project report. Though there are separate branches for the flow of armature current and field current. The dc shuntwound motor, running on direct current, has its field windings placed in parallel to the armature. The lab is equipped with dc seriesshunt motor, compound motor, universal motor, singlephase induction motor, singlephase transformer, threephase induction motor, threephase synchronous motor and threephase transformer. A dc generator is used to provide a dynamic, variable load on the shaft of the dc motor in the dynamometer cradle. That is the reason behind naming it a dc shunt motor.
So the load test could be performed in two ways ie, by direct loading by indirectly loading in case of direct loading the motor is provide. Besides, as part of an integrated and comprehensive study on the system developed for the needs of the labor was used matlab and. To obtain the external characteristics of dc shunt and compound generators. C of a dc shunt generator and to determine its critical. Dc motor lab report electric motor quantity scribd. Electrical machines lab report 12 eet2166 mmu studocu. Apparatus range type quantity 1 ammeter 020a mc 1 2 voltmeter 0300v mc 1 3 rheostat 1250, 0. Electrical machinel dc laboratory manual grietelectrical and.
Components of the shunt motor are the armature, labeled a1 and a 2, and the field, labeled f1 and f2. To determine the efficiency of the given dc shunt motor by conducting load test. Speed control of dc shunt motor by armature and field control. Since they are connected in parallel, the armature and field windings are exposed to the same supply voltage. Automation results into better quality, increased production an reduced costs. The purpose of this experiment is to obtain the load characteristics of dc motors, and show how. Todays industries are increasingly demanding process automation in all sectors. To study the properties of the separatelyexcited dc shunt generator under noload and fullload.
In this experiment we aim to conduct a noload test on a dc generator to determine its open circuit characteristics followed by a load test on a dc shunt generator to determine its external load characteristics. Power supply, dai, direct current machine dc motor 8211, electrodynamometer. Dc shunt motor should be started and stopped under no load condition. The dc shunt motor is 120vdc with rated speed of 1800 revolutions per minute. Now close switch s1 and slowly increase the voltage supplied to 3phase induction motor using autotransformer until it rotates at the rated speed of dc machine. Introduction the purpose of this experiment is to examine the construction of a dc motor generator, to learn the basic motor wiring connections, and to study the performance characteristics of a shunt and series dc motor. If the dc line voltage is constant, then the armature voltage and the field strength will be constant. To obtain the performance characteristics of dc shunt motor by using load test. Students should report to the labs concerned as per the timetable. Laboratory studies of speed control of dc shunt motor. Pdf laboratory manual electrical machines ayyappa javangula. As such, the field windings and armature are connected in a parallel combination, and in electrical terminology a parallel combination is known as a shunt.
Speed control of dc shunt motor your electrical guide. Lab report of electrical machines for lab1 characteristics of dc shunt motor, lab 1. Experiment 5 dc motor speed control it is prefered that students answer the questions before doing the lab because that provides the background information needed for this lab. Load tests on a threephase induction motor and measurement of the inrush current objectives. The coils in the shunt field are composed of many turns of small wire, resulting in low shunt field current and moderate armature current. Pdf speed control of dc motor by using pwm technique. To understand the load characteristics of dc shunt motors. Speed control of dc shunt motor with field and armature rheostat control 79 2.
Its operation is based on the principle that when a current carrying conductor is placed in a. The shunt field windings of a dc shunt motor are made of smaller gauge wire, but they have many more turns than a serieswound dc motor. To obtain the load performance characteristics of a threephase squirrelcage induction motor. The motor is brought to its rated speed by cutting out the rheostat r 2. View lab report lab5 from elet 64 at university of houston. It is, therefore, apparent that the shunt motor should run at a reasonably constant speed. The different methods of speed control of dc shunt motor are flux control method, armature control method and voltage control method. The lab is equipped with dc seriesshunt motor, compound motor, universal motor. The lab is equipped with various tests and monitoring equipment also. To draw the performance characteristics of the given dc shunt motor by conducting load test. Dc generator external characteristics of shunt generator. November 4, 2016 12 of 21 dc dc ra rfld1 e vt f1 f4 a1 a2 motor.
The field of the shunt motor is supplied from a constantvoltage exciter e. Speed control of dc shunt motor and 3ph induction motor. So, both the w indin gs are supplied w ith same mag nitude of. Scribd is the worlds largest social reading and publishing site. The tuned controllers will be implemented in realtime on ds1104 to perform the closeloop speed control of the dcmotor.
To examine the behavior of dc shunt and compound motors under load. A dc shunt motor also known as a shunt wound dc motor is a type of selfexcited dc motor where the field windings are shunted to or are connected in parallel to the armature winding of the motor. Electrical machines for mechatronics laboratory 6 4 altering the armature voltage procedure using the lab equipments shown in figure 6. That method is to change the terminal voltage of the motor. Two digital multimeters and fluke power quality meter with banana cables from the. Performance characteristics of dc generators objectives. Electric machines convert electrical energy to mechanical energy and viceversa, as shown in fig. The flux of a dc motor can be changed by changing ish with help of a shunt field rheostat.
This lab manual provides a platform to the students for understanding the basic concepts of. Push the start button at the bench panel to run the generator at rated speed 1730 rpm and no load. The armature of the shunt motor m whose speed is to be controlled is connected directly to a d. Same voltage is applied to both shunt winding and armature in this motor. To measure the inrush current when the motor starts. In order to specify the equivalent circuit parameters for this model it is necessary to set the model parameterization parameter to by equivalent circuit parameters. Press the output button of the dc power supply to connect the 240 volts dc source to the dc motor field shunt to generate the field current i f record the voltage generated v t when i f is zero turn slowly the power supply current knob in clockwise cw direction to adjust the field.
This parallel configuration allows independent path of current for field winding and armature. Construction and principle of operation of the shunt dc motor. Set the inserted field resistance and the inserted armature resistance to their maximum values. To discover the characteristic change in torque output of a dc shunt motor as it is loaded. Discussion the separatelyexcited generator experiment 27 has many applications. Keep in mind, however, that they cannot produce high starting torque, so the load at startup must be small. The characteristics of a shunt motor reveal that it is an approximately constant speed motor.
Since ish is relatively small, shunt field rheostat has to carry only a small current, which means i2. Speed control of dc shunt motor with field and armature. To determine the load characteristics of dc shunt motor. Discussion a dc motorgenerator can run either as a motor or as a generator. Using a measurement system with very low systematic type b uncertainty, it is possible, perhaps tempting, to underestimate the type a uncertainty contribution of the shunt under test. Apparatus range type quantity 1 ammeter 020a mc 1 2 voltmeter 0300v mc 1 3 rheostat 1250. To obtain the performance characteristics of a dc shunt motor by load test. Dc motor principle a machine that converts dc power into mechanical energy is known as dc motor. What is a dc shunt motor and its advantage and disadvantage. Introduction to dc motors 1 ee 448 lab experiment no. To conduct load test on dc shunt motor and to find efficiency. Electrical machines for mechatronics laboratory 7 4 speed control of series dc motors unlike with the shunt dc motor, there is only one efficient way to change the speed a series dc motor. Applications that meet these criteria and are suitable for dc shunt motors include machines tool such. Report format lab write ups should consist of the following sections.
Lathes, drills, boring mills, shapers, spinning, and weaving machines series motor. The high number of turns allows a strong magnetic field to be generated, but the smaller gauge wires provide a high resistance and limit the current flowing through the shunt coil. Working principle from the above circuit diagram, we can conclude that if we want to increase the speed of the shunt motor, we will vary the field resistance. Objective to study the torque vs speed characteristics of a shunt wound dc motor.
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