Combined armature and field speed control of dc motor for. This parallel configuration allows independent path of current for field winding and armature. The fact that the power supply of a dc motor connects directly to the field of the motor allows for precise voltage control, which is necessary with speed and torque control applications. This research will be focused to judge the performance of dc shunt motor by the implementation of different kinds of controllers such as.
On combining equation 5 and equation 12 we get a new equation shown in fig. M1 may be any ac motor or dc motor with constant speed. Proportional p control which removes the delay and provides fast control. For this reason, they are increasingly used as a tool for joining components. Dc motors are transducers because they convert electrical power pin into. Despite the load changes, shunt dc motor can maintain constant speed. View notes speedcontrolofdcshuntmotor from boston 6.
By means of this method, the motor can be worked at any speed up to its maximum speed. The set up for speed control of dc shunt motor by armature voltage control method is shown in the figure. In this work, a new hybrid algorithm has been developed by combining particle. In a shunt dc motor, the armature and field windings are linked in parallel. Dec 25, 2017 in this video you will learn about speed control of dc shunt motor now you can join our whatsapp group. Conclusion in this lab experiment the dc motor speed control. Working principle of dc shunt motor your electrical guide. Speed control of shunt and separately excited dc motors by armature current control method. These generators combine the characteristics of series and shunt generators. May 24, 2015 merits and demerits of rheostatic control method 1. This double dependence makes it impossible to keep the speed sensibly constant on rapidly changing loads.
This kind of winding is called shunt winding and the motor shunt dc motor creation and principle of operation of a shunt dc motor is same as any other dc motor. Bc354 pwm dc motor speed control installation and operating. C shunt motor as a function of armature voltage, field current, and external. Speed control of a dc motor using controllers science publishing. Hence the armature current differs and the speed of a dc shunt motor will continue constant which is shown in the fig dotted line ab. Before discussing the speed control of dc motor, let us first establish the expression of the speed of a dc motor. The motor back emf eb and speed of the motor can be changed. A shunt dc motor has good speed regulation even as the load varies.
Pdf brushless dc motor is used in many applications as battery operated. A rheostat is connected in series with armature winding. This lab allowed us to further investigate the characteristics of the various dc motor speed control schemes. Though there are separate branches for the flow of armature current and field current. To study the methods of controlling the speed of shunt dc motor. In this paper a comparison is made for speed control of dc motor by using. Comparative analysis of speed control techniques of dc motors. Therefore it is strongly recommended to equip hoist drives with analogue tacho or encoder. Speed control of dc motor shunt, series and compound.
That is the reason behind naming it a dc shunt motor. Nov 01, 2001 pwm motor drive controllers chop sine waves or dc voltages into signals of varying frequency and duty cycle. The serieswound motor in this type figure 1 the field is in series with the armature. Speed control of shunt motors i variation of flux or flux control method it is seen. The basic equation of the armature control method, n is. The different methods of speed control in dc shunt motors are 1. Speed control of dc shunt motor using 12 pulse rectifier. As resistance increased, the value of the field current will reduce.
This motor is used when both a high starting torque and good speed regulation is needed. Speed control of dc series motor can be done either by armature control or by field control. An efficient method for speed control of dc shunt motor using. Measurement of efficiency of shunt and series motors. The dcs800 solution the dcs800 control structure can fit to the demands of series wound motors. 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. Factors controlling motor speed it has been shown earlier that the speed of a. The 512c provides effective torque and speed control of permanent magnet or. What are the methods for controlling the speed of a dc shunt.
Kimberley keller, in electrical safety code manual, 2010. 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. Dc motors provide excellent speed control for acceleration and deceleration with effective and simple torque control. Construction and principle of operation of the shunt dc motor. Before discussing the speed control of dc shunt motor, we have to find the factors affecting the speed of a dc motor. Working principle of dc shunt motor, dc series motor and all other dc motors can be stated as follows. Speed control methods of dc motor shunt, series motors. The shunt motors are used where constant speed is required and starting conditions are not severe. There are two types of controls which were made in order to control the speed as. In this lab experiment, the dc motor speed control was studied. Tarun agarwal is the chief customer support officer at.
By varying the value of r we can vary the voltage across the armature. This paper discusses the speed and torque control of a shunt dc motor through matlab simulink simulations. Figure 1 shows a simplified pwm drive controller schematic for a dc motor. Keywordsseparately excited dc motor, speed control of. Hence dc shunt motors are typically used applications that. Many parameters can be obtained directly by using a motion controller, such. Dc shunt motor speed control and analysis using ziegler. In this post, we will discuss about various speed control methods of dc shunt motor. In the case of a dc motor, the magnetic field is produced by the field winding.
Pdf this paper describes the speed control of a dc shunt motor using conventional controllers pid, imc and. The armature of the shunt motor m whose speed is to be controlled is connected directly to a d. The compound motors are used where higher starting torque and fairly. The field rheostat is connected in series with the shunt field circuit. The current in the field coil and the armature are independent of one another. A motor s speed results from the signals average amplitude of a chopped voltage. 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. The various applications of dc shunt motor are in lathe machines, centrifugal pumps, fans, blowers, conveyors, lifts, weaving machine, spinning machines, etc. This paper describes the speed control of a dc shunt motor using conventional. As you know that the construction of any type of dc motor is very similar to a dc generator. Equivalent circuit of shuntexcited dc machine e a k. Find resistance to be added to the field circuit to increase speed to rpm at an armature current of 80 a. Same voltage is applied to both shunt winding and armature in this motor.
Armature resistance control and field flux control the dc motor converts the mechanical power into dc electrical power. A motors speed results from the signals average amplitude of a chopped voltage. The characteristics of a shunt motor reveal that it is an approximately constant speed motor. Speed control of dc shunt motor with comparative analysis. Applications of dc machines motors and generators circuit. P3 odd semester examination 2019 department of eee, university of rajshahi name of the instructor. Whenever the shunt motor load is increased e b vi a r a and flux reduces as a result drop in the armature resistance and armature reaction. C shunt motor as a function of armature voltage, field current, and external resistance in the armature circuit. Drives without load and friction can not be controlled by emf speed feedback at all. Speed of a shunt dc motor can be easily controlled. 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. When the load increases the armature tends to slow down. The curve becomes steeper and the speed decreases rapidly as the resistance is increased. Lathes, drills, boring mills, shapers, spinning, and weaving machines series motor.
Speed control of dc shunt motor with field and armature rheostat control 79 2. Speed control of dc shunt motor with field and armature. Explain the effect of motor reaction in a dc generator. Thyristor scr speed control of a dc shunt motor dspace repository thyristor scr speed control of a dc shunt motor. 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. The voltage applied to the motor may be reversed by backing the field current of generator through controller fc. 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. Dec 29, 2015 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. Active bridge limits the ac line inrush current when power is turned on and also prevents high speed runaway if the power transistor shorts. In electrical terms, parallel is generally denoted as shunt. Pdf speed control of a dc motor using controllers researchgate. This method is done by inserting the variable resistance rc in series with the armature. The arrangement of this system is as shown in the figure at right. 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.
In electrical terminology, a parallel connection is called shunt. Since they are connected in parallel, the armature and field windings are exposed to the same supply voltage. It should, however, be noted that by combining the two methods, speeds. The field of the shunt motor is supplied from a constantvoltage exciter e. Jul 11, 2019 speed control of a dc motor is either done manually by the operator or by means of an automatic control device. When a current carrying conductor is placed in a magnetic field, it experiences a force. 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 again, the expression of back emf in a dc motor is where. The controller output is now increased in a step from 100 to 120 v. 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. The controllers input converter rectifies ac line voltage and filters it into dc. On the other hand, back emf reduces marginally more than that the. Among the three types of dc motors, such as series, shunt and separately. Therefore the voltage drops i a r a will be negligible as compared to the external supply voltage v. Title of the experiment page no 7 retardation test on dc shunt motor. Speed control methods of dc shunt motor my tech info. The dc shunt motor is 120vdc with rated speed of 1800 revolutions per minute. As stated above this method will increase the losses. Since load is very small in a shunt motor, armature current is also very low. On occasion, a field regulator is contained within the field circuit of dc shunt motor for additional speed adjustment.
When constant speed service at low speeds is required, dc shunt motors are preferred over synchronous motors. Central composite design of experiments based experimental designed has been applied and number of experiments have been performed. Electronic motor burnout protection shuts down the control if a prolonged overload condition exists. As the rotating speed of dc shunt motor depends on armature voltage and field current applied to the shunt motor, therefore, these two process parameters were varied during experimentation. Mathematical modeling of dc shunt motor dc shunt motors have the field coil in parallel shunt with the armature. The speed of a shunt motor can be changed by flux control method. Factors controlling motor speed 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. Speed control of dc motor shunt motor and series motor. Speedcontrolofdcshuntmotor page 1 experiment no 9 aim. Dc motor is enhanced by controlling both armature voltage. Speed changes with every change in load, because speed variations depend not only on controlling resistance but on load current also. Pwm motordrive controllers chop sine waves or dc voltages into signals of varying frequency and duty cycle. As a result, these motors have excellent speed control 11. Merits and demerits of rheostatic control method 1.
Speed control of shunt dc motor johurul islam academia. Speed control of dc shunt motor your electrical guide. Hence dc shunt motors are typically used applications that require five or more horse power 8. When the driven load requires a wide range of speed control, both below and above the base speed, a dc shunt motor is employed. 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. May 25, 2015 factors controlling motor speed 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. Armature control of dc series motor speed adjustment of dc series motor by armature control may be done by any one of the methods that follow, 1.
Short circuit protection protects control from a short circuit at motor connections. This armature control method is based on the fact that by varying the voltage across the required voltage. 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. Dc motors classes, speed control and starting of dc motors on photo. This system is used where very sensitive speed control of motor is required e. The dc shuntwound motor, running on direct current, has its field windings placed in parallel to the armature. Therefore, for constant speed drives in industry dc shunt motors are employed. Shunt dc motors electrical calculations and induction motor.