In this article, i will discuss what is separately excited dc motor, applications of separately excited dc motor, speed control methods of separately excited dc motor, circuit diagram of speed control of separately excited dc motor by armature voltage control method, circuit diagram of speed control of separately excited dc motor by field flux control. Speed control of shunt and separately excited dc motors by armature current control method. Speed control methods of dc motor speed control of shunt motor 1. Separately excited electronic motor speed controller. Speed control of separately excited dc motor by ppt 2 free download as powerpoint presentation. This paper presents the speed control of a separately excited dc motor using fuzzy. Speed of dc motor can be varied by following methods armature voltage control for below base speed field flux control for above base speed armature resistance control here, we are using armature voltage control method for speed control. The purpose is to achieve accurate trajectory control of the speed of saperately excited dc motor, especially when the motor and load parameters are unknown. Dc motors are widely used in industry because of its low cost, less complex control structure and wide range of speed and torque. Many methods are available to regulate the speed of a separately excited dc motor such as pid control, fuzzy logic control, neural network method. What is the difference between armature voltage control and.
Speed control of a separately excited dc motor free download as word doc. This paper also discusses speed control of a sedm using chopper circuit. We can see from the above graph, by increasing the resistance the line becomes steeper. Separately excited electronic motor speed controller model 12 sepex curtis model 1266 ar sepex controllers are programmable and microprocessor based, with an advanced mosfet power section for smooth and seamless control of separately excited motors. Pdf speed control of separately excited dc motor using.
As the name suggests, in case of a separately excited dc motor the supply is given separately to the field and armature windings. Speed control of dc motor using chopper slideshare. Cutaway view of a dc motor dc motors are found in many special industrial environments motors drive many types of loads from fans and pumps to presses and conveyors the major advantages of dc machines over generators are easy to control speed and torque regulation. Speed control by varying the armature circuit resistance 2. For analog circuit maximum controller output is 10 volts.
This makes it a necessity to employ a method to effectively control the speed of a separately excited dc motor. Conventional controllers are generally used to control the speed of the separately excited dc motors in various industrial applications. Speed control of dc motor using chopper free download as powerpoint presentation. Separately excited dc motor electronic components systems. The pi based speed control has many advantages like fast control, low cost and simplified structure 3. The resulting torque speed characteristic of a shunt dc motor is shown in fig.
The speed of a separately excited dc motor could be varied from zero to rated speed mainly by varying armature voltage in the constant torque region. Praveen kumar3, associate professor, mrec abstract this project presents a comparison of performance of controllers such as pi, pid controller, self tuned fuzzy controller for dc motor speed control. When power for the stator electromagnet is supplied by a separate dc source, either fixed or variable, the motor is known as a separately excited dc motor. Sometimes the term independentfield dc motor is also used. Jan 26, 2019 speed control of shunt and separately excited dc motors by field control method.
Chopper fed speed control of separatly excited dc motor. In order to maximize the efficiency of the dc motor with an appreciable speed control. The main distinguishing fact in these types of dc motor is that, the armature current does not flow through the field windings, as the field windin. The results are compared with controller tuned by pi, pid and zieglernichols method. This paper describes speed control of separately excited dc motor using chopper as power converter and pi as speed and current controller. Separately excited dc motor or as you remember permanent magnet dc motor is a special type where we use a permanent magnet to create the required magnetic field and we also know that it doesnt need to control the speed so its usually used in. The novelty of this paper lies in the application of nonlinear autoregressivemoving averagel2 controller for the speed control of sedm. Its quite simple to understand if you look at a dc motors working principle. Separately excited dc motor speed control of using various. Speed control of separately excited dc motor using triac. The driver circuit consists of microcontroller which control the duty cycle of the. Most of the speed control of dc motor product in the market was using ac as power source.
Dc series motor is controlled by the armature voltage method only. Types of dc motor self excited, separately excited dc motor. Abstract the aim of the paper is to control the separately excited dc motor by using the igbt based chopper. The main distinguishing fact in these types of dc motor is that, the armature current does not flow through the field windings, as the field winding is energized from a separate external source of dc current as shown in the figure beside. So motor will develops a back emf and a torque to balance load torque at particular speed 14, 15. 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. The torque speed relationship, valid for both shunt and separate excitation, is derived. Weakening of field causes increase in speed of the motor while strengthening the field causes decreases the speed. Close loop control is done in two loop, first inner current loop having currenttorque controller and outer speed controller loop control the speed. Simplified dc motor with an electromagnet as stator. Sep 30, 2017 speed torque characteristic of separately excited dc motor. Due to this the speed can be controlled for below rated speed and speed above the rated speed, respectively. The power semiconductor devices used for a chopper circuit can be force commutated thyristor, power bjt, mosfet, igbt and gto based chopper are used.
The speed control of a dc motor with high accuracy is essential. Presentation on ieee topic, speed control of dc motor using triac. The graph shows the torque speed characteristics of a shunt dc motor. The objective of this paper is to describe the principle of dc motor speed control using. Introduction the variable speed, reliability and high performance are three main characteristics of an electric drive system due to which it can be. Speed control of dc motor using chopper electric motor. Speed control of separately excited dc motor by ppt 2. With the the increasing use of power semicondutor units, the speed control of dc motor is increasingly getting sophisticated and precise. Armature resistance control and field flux control the dc motor converts the mechanical power into dc electrical power. Speed control of separately excited dc motor using self tuned fuzzy pid controller submitted by prahlad kumar sahoo and nirmal kumar barik in partial fulfillment of the requirements for the award of bachelor of technology degree in electrical engineering at the national institute of technology rourkela deemed university, is an. The separately excited dc motor can be controlled from below and up to rated speed. Speed control of separately excited dc motor moleykutty. The separately excited dc motors are mostly used in controlled drives, owing to the possibility of independent field and armature current control and related superior control features in a wide speed. Modeling and speed control of separately excited dc motor.
For traction application igbtmosfet controlled dc series motors are extensively. The performance of the proposed system has been compared with the traditional one using. Many situations demand change in the speed of the dc motor. Closed loop control, separately excited dc motor and dc motor. In a separately excited dc motor the supply is given separately to the field and armature windings.
R2 r1, by increasing the resistance to r2, the speed increases. This paper proposes the speed control of a separately excited dc motor varying armature voltage. M1 is the main motor whose speed control is required. The field winding is supplied by a separate dc source whose voltage is variable. It is found to be simple and high effective if the load disturbances is small. Applications of dc motor dc motor applications everywhere.
The problem with armature current and flux method is that both of them need a change in resistance. Optimization filter of speed is obtained using modulus hugging approach. Fuzzy speed control of separately excited dc motor using. Oct 17, 2014 mathematical modeling and close loop speed control of separately excited dc motor. Scribd is the worlds largest social reading and publishing site. The pi based speed control has many advantages like fast control. The rotor speed of the dc motor can be made to follow an arbitrarily selected trajectory.
By varying field flux should to achieve speed above the rated speed. Speed control of separately excited dc motor speed of this type of dc shunt motor is controlled by the following methods. Separately excited dc motor speed control using four quadrant chopper rishabh abhinav, jaya masand, piyush vidyarthi, gunja kumari, neha gupta abstract the speed of separately excited dc motor can be controlled from below and up to rated speed using chopper as a converter. Speed control of separately excited dc motor request pdf. Pdf speed control of separately excited dc motor using chopper. Dc motors are widely used in industries for various purposes. As we know, speed of a motor is given by if f is kept constant and also if. Speed adjustment of this type of motor is achieved from the following methods. 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.
After obtaining the complete model of dc drive system, the model is simulated by matlab. Speed control of separately excited dc motor using fuzzy. Yuva radha krishna and kishore biswal under the guidance of dr. Speed control techniques in separately excited dc motor by varying the armature voltage for below rated speed. Torque speed characteristic of a shunt or separately excited dc motor ind then, with constant v t, otherwise it affect the torque speed curve this equation is a straight line with a negative slope. Speed control of separately excited dc motor by armature. The field of this motor is permanently connected across the dc supply lines. Pdf speed control of separately excited dc motor with. Speed control of separately excited dc motor using chopper. Speed control of separately excited dc motor science. In this video, i describe how to control the speed of d. Speed control of separately excited dc motor using pid. Speed control of separately excited dc motor using pid controller.
What are the applications of a separately excited dc motor. Speed control of a separately excited dc motor rectifier. The speed of separately excited dc motor can be control by changing the armature voltage and changing field flux. A antiwindup technique is used in controller to avoid integrator windup problem. Separately excited dc motor, chopper circuit, hysteresis current control, speed control, model reference adaptive controller, fuzzy neural controller. Dc motor speed control is known more than other types. Starting analysis of separately excited dc motor by pi controller. The speed control techniques in separately excited dc motor, by varying the armature voltage for below rated speed 7. However, their application is limited to mills, mines and trains. The chopper circuit is used to control field voltage for achieving the desired speed. The novelty of this paper lies in the application of nonlinear autoregressivemoving average l2 controller for the speed control of sedm. Speed control techniques of separately excited dc motor. Types of dc motors and their applications electrical4u.
Speed of the motor can be controlled by varying v a and holding v f constant at its rated value. Figure 3shows the equivalent circuit of separately exited dc motorwhen a separately excited dc motor is excited by a field current of and an armature current of flows in the circuit. Speed control of separately excited dc motor and performance analysis by software simulation has been done. So the drawback of conventional controllers when high load has been applied to the dc motor. Certificate this thesis on speed control of separately excited dc motor using fuzzy control logic is presented in completion of partial requirement of bachelors degree in electrical engineering is written by us, t. There is an increase in speed increases until a specific point which is the intersection point in the graph. The supreme advantage of dc motors is having the control over speed. The methods are provided with their schematics and block diagram, the construction of each scheme was made in breadboard at the first. A dc motor has a current carrying coil placed in a magnetic field and hence the coil armature experiences a force in accordance with flemings left hand rule. Shunt motor is the most common types of dc motor where we connect the field winding parallel with the armature windings so this motor can be self excited from the armature windings and this gives it the feature of greatest speed regulation, simplified reversing control and low starting torque, so shunt motor is suitable for beltdriven. Due to all the limitations of the above mention speed control methods, this encouraged me to take up the challenge to develop a speed controller well suited to use in separately excited dc motor. Previously, you saw that a dc motor is made up basically of a fixed magnet stator and a rotating magnet rotor.
The armature circuit for a dc machine and two circuit connections for the armature and field circuits, a shunt connected machine and a separately excited machine are presented. Speed control of a separately excited dc motor engineering essay. Many dc motors use an electromagnet for the stator, as illustrated in figure 27. The circuit equation of a speed torque characteristic of separately excited dc motor whose armature, having a total of z conductors, is wound for 2p poles the brushes divide the winding into 2a parallel paths, is. Mathematical modeling and close loop speed control of separately excited dc motor. Separately excited dc motor speed control using four quadrant. Whereas in the constant power region, field flux should be reduced to achieve speed above the rated speed. For domestic and industrial applications separately excited direct current motors are widely used. Also the speed control of dc motor it may use in different applications, such as lathes, fans, pumps, disc and band saw drive requiring moderate, torques, electric traction, high speed tools, etc. By varying the resistance in the armature circuit rheostatic control 2. For a dc motor, there are many systems to signify the machine behavior with good accuracy. The separately excited dc motor can be controlled from. This paper proposes two methods of speed controlling for separately excited dc motor. The results show the superiority zieglernichols method for separately excited dc motor speed control, which leads to improve the transient and.
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