In practice variation of the three factors is used for speed control. Working principle of dc shunt motor your electrical guide. This motor is used when both a high starting torque and good speed regulation is needed. Variations of speed with armature voltage control at constant field current. Pdf online speed control of the shuntconnected dc motor. Tech student, department of electrical engineering mpct gwalior india 2assistant professor, department of electrical engineering mpct gwalior india. In shunt dc motors the variable resistance inserted as, field control method on shunt dc motor. In the case of a dc motor, the magnetic field is produced by the field winding. P3 odd semester examination 2019 department of eee, university of rajshahi name of the instructor. Dc motor speed control can be achieved by varying flux, armature voltage. The power supply of a dc motor connects directly to the field of the motor which allows for precise voltage control, speed and torque control applications 3.
The greatest advantage of dc motors may be speed control. Online speed control of the shunt connected dc motor via a neurocontroller. This paper discusses the speed and torquecontrol of a shunt dc motor through matlab simulink simulations. Before the magnetic saturation, the field flux is directly proportional to the field current.
May 05, 2016 the range of speed control and robust working adds to the usefulness of the dc motors. In this post, we will discuss about various speed control methods of dc shunt motor. Dec 11, 2016 history of dc motor michael faraday u. By series resistance in parallel with the field winding of the motor. This paper deal with the speed control of separately. Speed changes with every change in load, because speed variations depend not only on controlling resistance but on load current also. Dc shunt motor armature the parallel combination of two windings is connected across a common dc power supply. The less common method of speed control is by inserting a resistor in series with armature circuit. May 25, 2015 thyristor speed control of separatelyexcited d. Speed control of dc shunt motor with comparative analysis with pi and fuzzy controller approach bhaskar roy1 and shilpi sisodiya2 1 m.
In this video, i describe how to control the speed of d. Characteristics of dc shunt motor, dc series motor, dc. In the past, wardleonard method is used for voltage control method. These curves are also known as performance curves of a motor. Only series and compound dc motors are suitable for traction work. Tarun agarwal is the chief customer support officer at.
For example, in a shunt motor, placing a resistance in series with the shunt field reduces. We can use this technique to control motor speed above its rated value. Automation results into better quality, increased production an reduced costs. The speed characteristic of a shunt motor is different compared with a series motor. C shunt motor as a function of armature voltage, field current, and external resistance in the armature circuit.
That method is to change the terminal voltage of the motor. The resistance is then known as a diverter resistance. Dc shunt motor speed control and analysis using ziegler nichols algorithm with pid controller yogesh sharma l,a shis patra 2 1, 2 electrical engineering department, m. Variation of speed with variation of field current at constant voltage. The speed may also be higher if the applied shunt field voltage is lower than the value shown on the nameplate. What are the best ways to control the speed of dc motor.
The equation shows that the speed is dependent on the supply voltage v, the circuit resistance ra, and the field flux. In a shunt motor, the field winding, as we ll as the armature winding, is connected in. As dc power can be easily transported, dc motor contributes a lot to traction drives. Speed control methods of dc motor speed control of shunt motor 1. The application meets the following performance specifications. And the armature winding is connected to external supply voltage hence it. The problem with this method is that when we increase the resistance, the slope becomes steeper. Such a fine speed control is generally not possible with a.
Jul 11, 2019 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. This system is used where very sensitive speed control of motor is required e. The speed control of this type of motor is achieved by varying either the armature current or armature resistance or by varying the terminal voltage applied the speed relation of dc shunt type motor is given as n. This intentional change of drive speed is known as speed control of a dc motor. Speed control of dc shunt motor your electrical guide. This item appears in the following collections higher diploma in electrical and electronics engineering 22 projects. It directly provides rotary motion and, coupled with wheels or drums and cables, can provide translational motion. What are the factors affecting the speed of a dc shunt motor. 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. Pdf this paper presents the speed neural control of a shuntconnected dc motor. Motors plays an important role in energy conversion process. 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. Its operation is based on the principle that when a current carrying conductor is placed in a. For this example, we will assume that the input of.
Speed control of dc shunt motor with field and armature rheostat. The voltage applied to the motor may be reversed by backing the field current of generator through controller fc. Speed control of dc motor the speed of a dc motor is given by i flux control. 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.
The variable speed drives, which can control the speed of a. Ra when the armature current is increased the speed value can be decreased. Speed control methods of dc motor shunt, series motors. Feb 05, 2018 for a dc shunt motor if the field is excited separately through a breaker than by controlling the armature voltage we can control the speed of the motor. It is a machine which converts electrical energy into mechanical energy. This paper discusses the speed and torque control of a shunt dc motor through matlab simulink simulations. Speed control by varying the armature circuit resistance 2.
In fact, fine speed control is one of the reasons for the strong competitive position of d. Speed control of dc shunt motor by armature control. Dc motors although ac motors are used in most of the cases, dc motors have many applications and used for multipurpose applications. As resistance increased, the value of the field current will reduce. Speed control of shunt dc motor johurul islam academia. Speed control of dc motors the speed of a dc motor is given by the relationship. Control motor speed with a computer algorithm microcontroller 12 vdc motor ac tachometer amplifier 9 vdc power supply signal conditioning frequency. Thyristor scr speed control of a dc shunt motor dspace repository thyristor scr speed control of a dc shunt motor.
Speed control of dc motor shunt, series and compound. The different methods of speed control of dc shunt motor are flux control method, armature control method and voltage control method. Armature resistance control and field flux control the dc motor converts the mechanical power into dc electrical power. In a shunt motor, the field and armature windings are connected in parallel. If you are a student of electrical engineering then you should know that speed control of dc shunt motor. Dec 29, 2015 because of their selfregulating speed capabilities, dc shunt motors are ideal for applications where precise speed control is required. May 18, 2016 speed control of dc shunt motor sanjeev jamge. In this paper, various speed control techniques for a dc shunt motor namely. Speed control methods of dc shunt motor my tech info. Dart controls dc speed control,nema 412,100200vdc shunt.
Speed of a dc motor can be varied by varying flux, armature resistance or applied voltage. Another method used in traction consists of starting up two motors in series and then connecting them in parallel when a certain speed has been reached. Of course, before going to know speed control of dc shunt motor we will learn what is dc shunt motor. This double dependence makes it impossible to keep the speed sensibly constant on rapidly changing loads. This drive also providing the functions like start, stop, forward braking, reverse braking, increased and decreased speed of motor.
The speed of the dc shunt motor can be controlled by above and below rated speed. Speed control of dc motor full guide for controlling the. The different methods of speed control in dc shunt motors are 1. Before discussing the speed control of dc shunt motor, we have to find the factors affecting the speed of a dc motor. As we know, speed of a motor is given by if f is kept constant and also if a is neglected, then, n. Speed control of dc motor using scr pdf speed of the dc motor is controlled by controlling the armature voltage. As a dc shunt motor attains its complete speed, then the armature current can be directly connected to the motor load. The flux of a dc motor can be changed by changing ish with help of a shunt field. Speed control of dc motor shunt type aim a to study the speed control of dc motor below the normal range by armature resistance control and to plot speed vs armature voltage, characteristic. Field control method on separately excited dc motor.
It would be called speed control of separately excited dc motor. Equivalent circuit parameters are armature resistance ra 110 ohms, field resistance rf 2. Dc motor with speed and current closed loops, driven by etpu on mcf523x, rev. Indeed one of the primary reasons for the strong competitive position of dc motors in modern industrial drives is the wide range of speeds afforded. It will run equally well using either an ac or a dc voltage source. By decreasing the flux, the speed can be increased and vice versa. This paper describes a matlabsimulink realization of the direct current dc motor speed control method by controlling the voltage. We know that the expression of speed control dc motor is given as. We control the speed by adding a variable resistance in series with the shunt field, when we increase the resistance the field current reduces and by the way, the flux reduces and the speed increases. Working principle of dc shunt motor, dc series motor and all other dc motors can be stated as follows.
Even its utility can be multiplied using better power electronic. From the speed useful output power curve it is seen that the shunt motor has a definite speed at no load. Since they are connected in parallel, the armature and field windings are exposed to the same supply voltage. The speed control of dc motors are in general much more adaptable speed drives than ac motors which are associated with a constant speed rotating field. From the expression of the speed of a dc motor, we have seen that the speed of the motor is inversely proportional to its field flux. The speed of a shunt motor can be changed by flux control method. With the contribution of converter the efficiency and speed control ranges is enhanced to great extent. This research will be focused to judge the performance of dc shunt motor by the implementation of. May 24, 2015 merits and demerits of rheostatic control method 1. Speed control of dc motors field control shunt motor. Types of dc motors dc motor are of 3 types they are 1. Applications that meet these criteria and are suitable for dc shunt motors include machines tool such. Speed control of dc motor shunt motor and series motor.
The above mentioned experiment was again carried out using thyristors and a comparative study was. Speed control of dc shunt motor with comparative analysis. Blocks pertinent to the control of the dcmotor are modeled using. Therefore speed control of dc motor is two type armature control method field control method 3. Todays industries are increasingly demanding process automation in all sectors. Know about 3 important ways for dc motor speed control. Speed control of dc shunt motor with field and armature rheostat control 79 2. The dc shunt motor is useful for moderate speed control. Pdf speed control of dc motor by using pwm technique. At present, variable voltage is achieved by scr controlled ac to dc converter unit is used to. The arrangement of this system is as shown in the figure at right. Jul 11, 2019 often we want to control the speed of a dc motor on demand. With a dc series motor, the current and torque produced at standstill may be reduced by strengthening the. Speed control of dc shunt motor with field and armature.
The speed of the motor will increase if the armature voltage is higher than shown on the nameplate 2. Armature voltage is controlled using different single phase. Speed control of shunt dc motor two common ways in which the speed of a shunt dc machine can be controlled. When a current carrying conductor is placed in a magnetic field, it experiences a force. The electric equivalent circuit of the armature and the freebody diagram of the rotor are shown in the following figure. A common actuator in control systems is the dc motor. Looking for dart controls dc speed control,nema 412,100200vdc shunt wound volts,0 to 90180vdc voltage output,10 max. Dc motor principle a machine that converts dc power into mechanical energy is known as dc motor.
By using these electromagnets operating principle is depends on the flemings left hand rule to determine the direction of the force acting on the armature conductors of the dc motor. The dc shunt motor is well suitable for lathes, machine tools, driving, shafting. Because of their selfregulating speed capabilities, dc shunt motors are ideal for applications where precise speed control is required. Speed control of shunt motor flux control method it is seen. 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. By means of this method, the motor can be worked at any speed up to its maximum speed. In this article we will discuss about how to start and control the speed of traction motors. Dc motor speed control is carried out by use of four quadrant chopper drive. There is a limit to the maximum obtainable speed by this method due to poor commutation at week fluxes. In the flux control method for controlling the speed of d. When we talk about speed control of dc motor we said that there is ward leonard method of speed control which based on varying the applied voltage to the armature, in this system we have a dc motor m powered by a dc generator g and we use a motor generator set which consists of either ac or dc motor. To study the speed control of a dc shunt motor by the following methods. Dec 08, 2017 i discuss the field resistance methos of speed control of dc shunt machinesthis lecture is a bit longbut it is worth it i have also put a summary of the lecture in pdf at this link here. How to start and control the speed of traction motors.
M1 may be any ac motor or dc motor with constant speed. A shunt excited dc motors terminal voltage is 500 v. One of the most important features of the dc motor is that their speed can easily be control according to the requirement by using simple methods. On occasion, a field regulator is contained within the field circuit of dc shunt motor for additional speed adjustment. Introduction to dc motors 1 ee 448 lab experiment no. Speed control of a dc motor is either done manually by the operator or by means of an automatic control device. We can control the shunt field current by inserting a rheostat. A shunt dc motor has good speed regulation even as the load varies. Speed control methods of dc shunt as well as dc series motor are. Blocks pertinent to the control of the dc motor are modeled using basic blocks. The dc shunt motor is 120vdc with rated speed of 1800 revolutions per minute. A compound dc motor connects the armature and fields windings in a shunt and a series combination to give it characteristics of both a shunt and a series dc motor.
Until the late of the 1980s, when the variable frequency drive was not invented, dc motor was the best option for variable speed application. What are the methods for controlling the speed of a dc shunt. Measure the armature and the shunt field voltages at the motor terminals to be sure they are in accordance with the nameplate data. Dc motor with speed and current closed loops, driven by etpu. Apply a load to your dc motor by varying the dynamometer control knob until the scale marked on the dynamometer. The thyristor based dc drive with the analog and digital feedback control schemes are used for the speed control technique of dc motor. We use this method to increase the speed of these motors above the base speed. This paper describes a matlabsimulink realization of the direct current dc motor speed control method by controlling the voltage applied to the field circuit of a separately excited dc motor in. Keep in mind, however, that they cannot produce high starting torque, so the load at startup must be small. When the load is extremely low within a shunt motor, then the armature current can also be low. E b vi a r a here, eb back emf, in volts ia armature current, in amps ra armature resistance, in ohms v terminal voltage, in volts.
Therefore the voltage drops i a r a will be negligible as compared to the external supply voltage v. Calculate the induced voltage, the output power, the efficiency and the torque of the motor if the mechanical and the magnetic losses are 900. This is different to speed regulation where the speed is trying to be maintained or. For a dc shunt motor field winding is connected in series with the armature and current passing through the series winding is same as the armature current therefore the series field winding has fewer turns of thick wire than the shunt field winding. What is a dc shunt motor definition, characteristics. Characteristics of dc shunt motor, dc series motor, dc compound motor. Speed control of dc shunt motor by varying field flux. The electrical machine is one of the most important subject in electrical engineering.
422 219 398 1212 1506 1451 1338 1597 828 235 653 1568 1028 1184 640 569 1439 411 600 1220 1387 478 831 807 596 517 555 441 79