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. The physical implications of the equations regarding device behaviour, and the need for speed control, are easily understood. On occasion, a field regulator is contained within the field circuit of dc shunt motor for additional speed adjustment. Another set up consisted of half bridge rectifier consisting of thyristor wherein the speed control for the same dc motor was carried out using the firing angle of the thyristor. When supply voltage v and armature resistance ra are kept. Xpy tachs have ul listing, file number e109527, csa file number lr368415. Find powerpoint presentations and slides using the power of, find free presentations research about speed control of a dc shunt motor ppt.
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. The voltage applied to the motor may be reversed by backing the field current of generator through controller fc. Since they are connected in parallel, the armature and field windings are exposed to the same supply voltage. In an open loop control, the only components in the system.
The above mentioned experiment was again carried out using thyristors and a. Before going further we need to discuss the hbridge. The fullycontrolled circuit, in which four thyristors are used rather than two with two diodes, is. It has three external terminals anode, gate, and cathode and uses the alternative symbols of figure 1a and has the transistor equivalent circuit of figure 1b.
Conclusion in this lab experiment the dc motor speed. It would be called speed control of separately excited dc motor. The dc motor whose speed is to be controlled using the pid controller in the fig. He has 8 years of experience in customer support, operations and administration. 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. High quality ball bearing motors with precision machined. Tarun agarwal is the chief customer support officer at edgefx technologies pvt ltd. Special circuitry automatically accepts ac line input voltages of 115 volts ac to 208230 volts. The sce speed control unit provides adjustable current limit with led indica tor, ir voltage compensa on to provide 1% speed regula on throughout 60. Working of control panel for the speed control through armature control and field control we will be using face plate type starter also in order to limit the starting current, also otherwise higher capacity of armature control rheostat will be required.
A 240v dc shunt dc motor has an armature resistance of 0. In this lab experiment, the dc motor speed control was studied. This item appears in the following collections higher diploma in electrical and electronics engineering 22 projects for higher diploma in electrical. Speed control of dc shunt motor with field andarmature rheostat control simultaneously, volume 3 anurag dwivedi notes by priya yadav speed control of dc motor using neural network configuration amit atri, md. Speed control of dc shunt motor with field and armature. Dc shunt motor speed control and analysis using ziegler. The thyristor based dc drive with the analog and digital feedback control schemes are used for the speed control technique of dc motor. The dc motor converts the mechanical power into dc electrical power. The dc motor speed control is achieved by controlling the voltage applied to the armature circuit using three phase ac dc converter drive.
There are two types of controls which were made in order to control the speed as well as the current. Figure 2 shows the basic way of using the scr as a dc switch, with the anode positive relative to the cathode, and the scr controlled via its gate. It has been shown earlier that the speed of a motor is given by the relation it is obvious that the speed can be controlled by varying i fluxpole, f flux control ii resistance ra of armature circuit rheostatic control and iii applied voltage v voltage con trol. Dc motor speed control is carried out by use of four quadrant chopper drive. Generally, a dc motor consists of either an electromagnet or a permanent magnet and a wounded coil known as the armature. Types of dc motors dc motor are of 3 types they are 1. This example shows two dc motor control techniques for reducing the sensitivity of w to load variations changes in the torque opposed by the motor load. Load test on dc shunt motor to draw speed torque and horse power efficiency characteristics. Every where i see is the pwm method for speed control, mostly in hbridge manner equiped with transistors. This paper deal with various method of speed control of dc motor and literature. As we know, speed of a motor is given by if f is kept constant and also if. 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 using scr pdf speed of the dc motor is controlled by controlling the armature voltage. The concept of the speed regulation is different from the speed control. The armature of the shunt motor m whose speed is to be controlled is connected directly to a d. In this chapter, speed control of a dc motor using pulse width modulation pwm technique is described. The 85 mt5f features heavyduty components like an scr speed control unit, dc shunt.
Comp speed regulation adjusts the control output to compensate for speed changes caused by varying motor loads. The scr a and b rectifier, the op voltage of transformer t1 and apply this pulsating dc voltages to the armature winding and rectifier c supplies similar voltages to the motor field winding. Direct current is applied to the armature by means of a carbon brush or by means of electromagnetic induction. 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. Thyristor scr speed control of a dc shunt motor dspace repository. Speed of the dc motor is controlled by controlling the armature voltage. View and download powerpoint presentations on speed control of a dc shunt motor ppt.
Shunt motor using sa based tuning of a pid controller. Full wave scr control with free wheeling diode nema type k field power supply allows use with shunt wound dc motors as well as permanent magnet motors. The figure shows an scr circuit that can be used for the speed control of dc shunt motor. The present research work deals with the application of response surface methodology rsm for controlling as well as estimating the rotating speed of a dc shunt motor. A comparison between the application of three phase semi. Speed control of a dc motor is either done manually by the operator or by means of an automatic control device.
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. Now this circuit has mainly two functions, first is to drive a dc motor from low power control signals and the other is to change the direction of rotation of dc motor. In the armature control method, the speed of the dc shunt motor is directly proportional to the back emf eb and eb v iara. Therefore the voltage drops i a r a will be negligible as compared to the external supply voltage v. The characteristics of a shunt motor reveal that it is an approximately constant speed motor. Before discussing the speed control of dc shunt motor, we have to find the factors affecting the speed of a dc motor. Pdf the proposed work deals with optimal tuning of. Subhajit bose03 shuvankar das02 binoy mourya09 sushobhan sarkar06 prosenjit debnath35 3. I dont know why people love pwm so much for controlling the speed of the dc ac motor.
The variable speed motor control training system features heavyduty components like an scr speed control unit, dc shunt wound motor, and fuse block to give learners realworld practice on scr speed control skills such as connecting and operating a motor with scr halfwave speed control, measuring the performance of scr halfwave speed control. You can adjust the speed of rotation of the spindle motor from 560 cycles per minute. An scr is a fourlayer pnpn silicon semiconductor device. It operates at a switching frequency greater than 16khz to provide high motor efficiency and quiet operation. In this circuit, the supply voltage to the armature can be varied by varying the conduction angle of the scr, so the smooth variation in speed is possible. The above mentioned experiment was again carried out using thyristors and a comparative study was. Armature voltage is controlled using different single phase. Introduction the speed of dc motor is directly proportional to the supply voltage, if we reduce the supply voltage from 12v to 6v, the motor will run at half the speed. You can sense the effect of speed control of dc motor in the movement of robotic. Hi, im developing motor speed controller for permanent magnet synchronous motor pmsm. Pdf the versatile control characteristics of dc motor have contributed in the extensive use of dc motor in the industry.
Pdf thyristor based speed control techniques of dc motor. Accel acceleration allows adjustment of the motor acceleration from a minimum of 0. So by this we can conclude the pwm can be used to vary the motor speed. To study the methods of controlling the speed of shunt dc motor. Speed control of dc motor is the most important feature we interest in, when we control the speed we vary it according to the requirements and the operation we need. Therefore, for constant speed drives in industry dc shunt motors are employed. Though there are separate branches for the flow of armature current and field current.
By altering the firing angle of the thyristors the mean value of the. The deceleration time depends on the accel setting. The field of the shunt motor is supplied from a constantvoltage exciter e. I have my university final year project that is scr based dc motor 1phase speed control. Armature voltage is controlled using different single phase ac dc converter. Speed control of dc shunt motor using 12 pulse rectifier. Adjustable accel, decel, current limit, ir comp, min and max speed. This lab allowed us to further investigate the characteristics of the various dc motor speed control schemes. The dc motor can control by various method which are as field control, armature voltage control, armature resistance control. The 85mt5f features heavyduty components like an scr speed control unit, dc shunt wound motor, and fuse block to give learners realworld prac ce on scr speed control skills such as connec ng and opera ng a motor with scr halfwave speed control, measuring the performance of scr halfwave speed control, and troubleshoo ng an scr speed. Speed control methods of dc shunt motor my tech info. An efficient method for speed control of dc shunt motor. When constant speed service at low speeds is required, dc shunt motors are preferred over synchronous motors. 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.
Scr phaseangle controlled drive by changing the firing angle, variable dc output voltage can be obtained. Scr dc motor control the speed of dc motor can be control by using scr in ac circuit as shown in the below figure. This is speed motor controller circuit of 12v dc motor. Speed control of dc shunt motor your electrical guide. These methods as applied to shunt, compound and series motors will be discussed below. Ilyaseee department, mriu, faridabad speed control of dc motor using. Speed control of dc shunt motor with field and armature rheostat control 79 2. Connect the dc motor for speed control as shown in fig a for armature and field. Half converter, semi converter, full converter and dual converter are some of the. It is designed for applications requiring washdown watertight integrity. The speed of dc motor can be control by usingscrin ac circuit as shown in the below figure. Speed control of electrical motors is an old but evergreen topic in industries. 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.
146 473 1207 1067 152 458 691 1626 222 306 733 1569 65 209 907 658 22 1534 301 1586 225 1391 807 1082 325 376 1444 690 419 1114 675 754 141 1452 1208 1375 418 970 1278 697