Speed control of dc shunt motor your electrical guide. Dc shunt motor the higher the armature voltage, the faster the rotation. Such a fine speed control is generally not possible with a. This system is used where very sensitive speed control of motor is required e. Automation results into better quality, increased production an reduced costs. P3 odd semester examination 2019 department of eee. We shall use the same dcmotor for which the parameters were calculated in the previous experiment. Field control method on separately excited dc motor. Tarun agarwal is the chief customer support officer at edgefx technologies pvt ltd. The flux of a dc motor can be changed by changing ish with help of a shunt field. Speed control methods of dc shunt as well as dc series motor are. This type of motor has good speed regulation even as the load varies, but does not have the starting torque of a series dc motor. To study the methods of controlling the speed of shunt dc motor.
M1 may be any ac motor or dc motor with constant speed. The speed characteristic of a shunt motor is different compared with a series motor. 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. Pdf speed and torque control of a dc shunt motor elmer r. The problem with this method is that when we increase the resistance, the slope becomes steeper. This paper describes a matlabsimulink realization of the. The purpose of this experiment is to design and implement a closeloop speed control of a dcmotor drive. 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.
In this method, a variable resistance known as shunt field rheostat is placed in series with shunt field winding as shown in fig. This motor is used when both a high starting torque and good speed regulation is needed. As a result, the dc shunt motor is capable of maintaining a constant speed irrespective of load changes. Speed control of dc shunt motor with field and armature rheostat control 79 2. In this lesson aspects of starting and speed control of d. The full load torque rating of the dc motor must be equal to, or greater than, that of the ac motor. Dc shunt motor speed control and analysis using ziegler.
Shunt wound dc motor or dc shunt motor is a selfexcited dc motor whereas we said before at previous article types of dc motor that it operates on direct current and the field winding is connected in parallel to the armature winding so both windings exposed to the same power supply voltage, and this motor able to maintain at a. Speed control of a dc motor is either done manually by the operator or by means of an automatic control device. In this paper, various speed control techniques for a dc shunt motor namely. The flux of a dc motor can be changed by changing ish with help of a shunt field rheostat. Because of this feature, this motor is used for automotive and industrial purposes where fine precision of the motor speed is required. Before the magnetic saturation, the field flux is directly proportional to the field current. Therefore speed of the 3 types of dc motors shunt, series and compound can be controlled by changing the quantities on the righthand. 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. At first, the controllers will be designed and tested on a simulation model of the dc motor. Speed control of shunt dc motor johurul islam academia. The simple rheostatic method provides a speed torque characteristic dc shunt motor with little hardness and little stability. Jul 11, 2019 speed control of a dc motor is either done manually by the operator or by means of an automatic control device. In fact, fine speed control is one of the reasons for the strong competitive position of d. 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.
Speed control of dc motor shunt motor and series motor. C shunt motor as a function of armature voltage, field current, and external resistance in the armature circuit. The purpose of this experiment is to design and implement a closeloop speed control of a dc motor drive. By means of this method, the motor can be worked at any speed up to its maximum speed. Speed control of dc shunt motor with field and armature rheostat. An intro to the four types of dc motors motion control blog. Speed control methods of dc motor speed control of shunt motor 1. Kbic scr dc motor speed controls kb electronics, inc. When the load is extremely low within a shunt motor, then the armature current can also be low. This paper discusses the speed and torque control of a shunt dc motor through matlab simulink simulations.
Speed control methods of dc shunt motor my tech info. Experiment 5 dc motor speed control walter scott, jr. Many dc motors use an electromagnet for the stator, as illustrated in figure 27. 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. Motors plays an important role in energy conversion process. Speed control of the separately excited dc machine. The less common method of speed control is by inserting a resistor in series with armature circuit. At first, the controllers will be designed and tested on a simulation model of. 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.
To study the methods of controlling the speed of separately excited dc motor. Dc motorgenerator module to demonstrate and explain the operation of. Simplified dc motor with an electromagnet as stator. Ac induction motor speed control so what can we do to control the speed of an ac induction motor. This paper discusses the speed and torquecontrol of a shunt dc motor through matlab simulink simulations. Speed of a dc motor we know, back emf of a dc motor eb is the induced emf due to rotation of the armature in magnetic field. 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. Since they are connected in parallel, the armature and field windings are exposed to the same supply voltage. The field current can be changed by changing the rheostat r connected in series with the field. Speed control of dc motor the speed of a dc motor is given by i flux control. In order for a dc motor to run, current mu st flow in the armature winding and the stator must develop a magnetic field flux, either by means of a shunt winding or a series winding or both. Pdf speed control of dc motor by using pwm technique.
Speed control of dc shunt motor by varying field flux. In a shunt motor, the field and armature windings are connected in parallel. In shunt dc motors the variable resistance inserted as, field control method on shunt dc motor. The different methods of speed control of dc shunt motor are flux control method, armature control method and voltage control method.
As resistance increased, the value of the field current will reduce. Thyristor scr speed control of a dc shunt motor dspace repository thyristor scr speed control of a dc shunt motor. Jun 12, 2019 before discussing the speed control of dc motor, let us first establish the expression of the speed of a dc motor. The torque developed by a dc motor is directly proportional to the armature current and the stator flux. The arrangement of this system is as shown in the figure at right. Armature resistance control and field flux control the dc motor converts the mechanical power into dc electrical power. Speed control of shunt dc motor two common ways in which the speed of a shunt dc machine can be controlled. This can be achieved by changing the field current. As a dc shunt motor attains its complete speed, then the armature current can be directly connected to the motor load. Content speed of a dc motor speed control methods of dc motor speed control of shunt motor speed control of series motor 3. The voltage equation of a dc motor is where e b is the back emf, v is the supply voltage, i a the armature current, and r a is the armature resistance. The speed of a shunt motor can be changed by flux control method. It is a machine which converts electrical energy into mechanical energy. Torque control of a shunt wound and dc motor of an electric vehicle.
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. Keep in mind, however, that they cannot produce high starting torque, so the load at startup must be small. 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. Speed control of dc shunt motor using microcontroller. Shunt motor is a special type of dc motor which runs at a constant speed. Because of their selfregulating speed capabilities, dc shunt motors are ideal for applications where precise speed control is required. What are the best ways to control the speed of dc motor. Power supply of dc motor connects directly to the field coils allows precise voltage control, which is necessary with speed and torque control applications. This item appears in the following collections higher diploma in electrical and electronics engineering 22 projects.
Aug 23, 2012 this video shows about how to control a dc motor speed with pulse width modulation keeping frequency constant and varying duty cycle using a free running mul. Though there are separate branches for the flow of armature current and field current. 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. We shall use the same dc motor for which the parameters were calculated in the previous experiment. Speed of a dc motor can be controlled by various ways, like flux control. Speed control of dc motor shunt, series and compound. In this video, i describe how to control the speed of d. Data sheet d210 kbic variable speed dc motor controls for shunt wound, pm and acdc motors 1100 11. A shunt dc motor connects the armature and field windings in parallel or shunt with a common d. The dc shunt motor is 120vdc with rated speed of 1800 revolutions per minute. 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. Adjusting the field resistance r f and thus the field flux adjusting the terminal voltage applied to the armature. Dc motor speed controller circuit using pwm electrical.
Set the shunt field rheostat control knob at its full cw position for. Speed control by varying the armature circuit resistance 2. Introduction to dc motors 1 ee 448 lab experiment no. One can control the speed of a dc shunt motor in two ways. Jan 26, 2019 field control method on separately excited dc motor. The voltage applied to the motor may be reversed by backing the field current of generator through controller fc. On occasion, a field regulator is contained within the field circuit of dc shunt motor for additional speed adjustment. By adjusting the duty cycle of pulse from pulse width modulation technique simultaneously.
Where,va is the voltage applied across the armature, n is the rotor speed and. In order to change the speed, we have to change flux. But using field and armature rheostat control method we can make it more versatile. This video shows about how to control a dc motor speed with pulse width modulation keeping frequency constant and varying duty cycle using a free running mul. Todays industries are increasingly demanding process automation in all sectors. Speed control methods of dc motor shunt, series motors. Dec 31, 2017 in this video, i describe how to control the speed of d. By decreasing the flux, the speed can be increased and vice versa. Therefore the voltage drops i a r a will be negligible as compared to the external supply voltage v. Dc shunt motor shunt wound dc motor principle, construction. Blocks pertinent to the control of the dcmotor are modeled using.
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. We use this method to increase the speed of these motors above the base speed. The variable speed drives, which can control the speed of a. Speed control of dc motor the speed of a dc motor is given by i. We can control the shunt field current by inserting a rheostat. Speed control of dc shunt motor with field and armature. He has 8 years of experience in customer support, operations and administration. Equivalent circuit parameters are armature resistance ra 110 ohms, field resistance rf 2. Provide excellent speed control for acceleration and deceleration.
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