Speed control of dc shunt motor pdf free

The dc shunt motor construction is the same as any type of dc motor. The electric equivalent circuit of the armature and the free body diagram of the rotor are shown in the following figure. Hence dc shunt motors are typically used applications that. Before discussing the speed control of dc shunt motor, we have to find the factors affecting the speed of a dc motor. Tarun agarwal is the chief customer support officer at. Lathes, drills, boring mills, shapers, spinning, and weaving machines series motor. Speed control of dc motor can be controlled by this method. Brushed dc motor drive circuits, brushless dc motor drive circuits, stepper motor drive circuits, drive software, writing a pwm value to the ccp registers with a midrange picmicro.

Since they are connected in parallel, the armature and field windings are exposed to the same supply voltage. Motors plays an important role in energy conversion process. If we add resistance in series with the armature, the armature current ia decreases and. 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. It is necessary to vary to dc voltage in order to control the speed of a dc motor. Blocks pertinent to the control of the dcmotor are modeled using. In this paper, various speed control techniques for a dc shunt motor namely. Therefore speed of the 3 types of dc motors shunt, series and compound can be controlled by changing the quantities on the righthand side of the equation above hence the speed can be varied by changing.

Dc motor control tips n tricks pdf 36p this note explains many basic circuits and software building blocks commonly used to control motors. 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. The characteristics of a shunt motor reveal that it is an approximately constant speed motor. Speed control of shunt excited motors a by changing field resistance b by changing armature voltage. The speed characteristic of a shunt motor is different compared with a series motor. The variable speed drives, which can control the speed of a. Pdf this paper discusses the speed and torque control of a shunt dc motor through matlab simulink simulations. Speed control of dc motor shunt, series and compound. From the expression of the speed of a dc motor, we have seen that the speed is directly proportional to the difference between supply voltage and its armature resistance drop. A thyristor consists of an anode, cathode, and a gate. The purpose of a motor speed controller is to take a signal representing the required speed, and to drive a motor at that speed. A thyristor is one type of device commonly used to convert ac to dc.

The less common method of speed control is by inserting a resistor in series with armature circuit. Find resistance to be added to the field circuit to increase speed to rpm at an armature current of 80 a. To study the speed control of a dc shunt motor by the following methods. By means of this method, the motor can be worked at any speed up to its maximum speed. In the armature control method, the speed of the dc motor is directly proportional to the back emf eb and eb v iara. In this chapter, speed control of a dc motor using pulse width modulation pwm technique is described. A rheostat is connected in series with armature winding.

Speed control of dc shunt motor can be easily achieved but in the case of the induction motor, it is difficult to achieve smooth speed control. 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. 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. Dc shunt motor speed control and analysis using ziegler. In this type figure 1 the field is in series with the armature. As you know that the construction of any type of dc motor is very similar to a dc generator. This is also well known that the dc machines can be used as a generator as well as as a motor, their is the difference of operation in both case i. In this method, we will control the speed of the motor by controlling the magnetic flux produced by field winding. Voltage can be applied to the terminals of the dc motor or. 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. Automation results into better quality, increased production an reduced costs. View notes speedcontrolofdcshuntmotor from boston 6. Though there are separate branches for the flow of armature current and field current.

A simple explanation of how to control the speed of a dc motor. Speed control methods of dc motor speed control of shunt motor 1. The speed of a shunt motor can be changed by flux control method. 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 constant speed with any load. Speed control methods of a dc motor can be varied by varying flux, armature resistance or applied voltage. As a result, these motors have excellent speed control 11. Speed control of shunt dc motor two common ways in which the speed of a shunt dc machine can be controlled. Apr 16, 2017 you need to power the field and armature separately. The armature of the shunt motor m whose speed is to be controlled is connected directly to a d. It is a machine which converts electrical energy into mechanical energy.

An adaptive speed control approach for dc shunt motors. Speed control can be achieved using dc drives in a number of ways. 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 shunt motor with field and armature. Before discussing the speed control of dc motor, let us first establish the expression of the speed of a dc motor. Jul 11, 2019 speed control of a dc motor is either done manually by the operator or by means of an automatic control device.

Adjusting the field resistance r f and thus the field flux adjusting the terminal voltage applied to the armature. This unit will discuss how these magnetic fields are produced in dc motors, and how magnetic fields induce voltage in dc generators. Dec 31, 2017 in this video, i describe how to control the speed of d. Speed control methods of dc shunt motor my tech info. The terminal voltage of the armature, v the external resistance in armature circuit, r a the flux per pole. To study the methods of controlling the speed of shunt dc motor. 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. Motor speed can be controlled by controlling armature voltage va armature current ia. What are the best ways to control the speed of dc motor. Jan 29, 2017 this video teach you to understand the speed control method of dc shunt motor with practical demonstration.

Disadvantages are high maintenance and low lifespan for high intensity uses. The current in the field coil and the armature are independent of one another. M1 may be any ac motor or dc motor with constant speed. Pulsewidth modulation pwm or dutycycle variation methods are commonly used in speed control of dc motors. The duty cycle is defined as the percentage of digital high to digital low plus digital high pulsewidth during a pwm period. The control algorithm is realized using a programmable logic controller. This motor can be constructed with the basic parts like field windings stator, a commutator and an armature rotor the working principle of a dc shunt motor is, whenever a dc motor is turned on, then dc flows throughout stator as well as the rotor. Armature resistance control and field flux control the dc motor converts the mechanical power into dc electrical power. Equivalent circuit of shunt excited dc machine e a k. Generally, a dc motor consists of either an electromagnet or a permanent magnet and a wounded coil known as the armature. 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. As resistance increased, the value of the field current will reduce. Series and shunt motors methods like flux control method,armature control method,voltage control method,wardleonard.

This paper discusses the speed and torque control of a shunt dc motor through matlab simulink simulations. This system is used where very sensitive speed control of motor is required e. Pdf speed control of dc motor by using pwm technique. The arrangement of this system is as shown in the figure at right. Speed control of dc motor using pulsewidth modulation. Speed control of dc motor using chopper linkedin slideshare. Voltage control can be via a mosfet pwm circuit, or for mains powered application, scrs. The different methods of speed control in dc shunt motors are 1. This method is used when speeds below the noload speed are required. 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. Enter your email below to receive free informative articles on electrical. It is because of in induction motor, the performance of induction motor in terms of power factor, efficiency etc. As a dc shunt motor attains its complete speed, then the armature current can be directly connected to the motor load.

The brushed dc electric motor generates torque directly from dc power supplied to the motor by using internal commutation, stationary magnets permanent or electromagnets, and rotating electromagnets advantages of a brushed dc motor include low initial cost, high reliability, and simple control of motor speed. Dc motor, generators and energy conversion devices lecture notes. The flux in the field winding is directly proportional to the field current and the field current is inversely proportional to the field resistance r f. It directly provides rotary motion and, coupled with wheels or drums and cables, can provide translational motion. The dc shunt motor is 120vdc with rated speed of 1800 revolutions per minute. A common actuator in control systems is the dc motor. What are the methods for controlling the speed of a dc. Variations of speed with armature voltage control at constant field current. The torque developed by a dc motor is directly proportional to the armature current and the stator flux. A shunt dc motor connects the armature and field windings in parallel or shunt with a common d. When the load is extremely low within a shunt motor, then the armature current can also be low. Comparison of three types of motor 1 the speed regulation in shunt motor is better than series motor 2 the starting torque of a series motor is more than other motor 3 both shunt and compound motors have definite no load speed, however series motors have dangerously high speed at no load.

Dc drives offer the ability to control the speed and torque of heavyduty dc motors in various industrial and other similar applications. Speed control of dc motor full guide for controlling the. Speedcontrolofdcshuntmotor page 1 experiment no 9 aim. 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. 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. You need to power the field and armature separately.

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 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 resulting torque speed characteristic of a shunt dc motor is shown in fig. Induction motor is practically a constant speed motor as the dc shunt motor. Flux control method speed is inversely proportional to. Speed control of shunt motor flux control method it is seen that speed of the motor is inversely proportional to flux. Speed control methods of dc motor shunt, series motors. Variation of speed with variation of field current at constant voltage. When supply voltage v and armature resistance ra are kept constant, the speed is directly proportional to armature current ia. Types of dc motors separately excited motor shunt excited motor. This type of dc motor is only used for direct coupling and other work where the load or part of the load is permanently coupled to the motor this will be seen from the speed torque characteristic, which shows that on no load or light load the speed will be very high and therefore dangerous. The concept of the speed regulation is different from the speed control.

In this video, i describe how to control the speed of d. This paper discusses the speed and torquecontrol of a shunt dc motor through matlab simulink simulations. The complex motor system is composed of a dc motor drivera tachogenerator. By varying the value of r we can vary the voltage across the armature. Dc motor generator module to demonstrate and explain the operation of dc motors and generators operating principle of dc motors as stated in unit 1, motors turn because of the interaction between two magnetic fields. Our sample motor has a winding that can be connected to either 150 vdc or 300 vdc. The equation shows that the speed is dependent on the supply voltage v, the circuit resistance ra, and the field flux. 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. Different speed control methods for different dc shunt and series methods are there. Speed control of dc shunt motor your electrical guide. In this method, a variable series resistor r e is put in the armature circuit. Field volts and amps shunt fields are typically wound for 150 vdc or 300 vdc. In general, the field gets constant voltage, and the armature gets variable voltage to control the speed. Thus, control policies for electric motors installed in industrial plants should be performed by using measurements of the output signal and a single voltage input.

The set up for speed control of dc shunt motor by armature voltage control method is shown in the figure. Design of plc based speed control of dc motor using pi controller free download abstract the purpose of this research is to analyzeimplement pi control for a simple dc shunt motor. Speed control of induction motor detailed explanation. On occasion, a field regulator is contained within the field circuit of dc shunt motor for additional speed adjustment.

For this example, we will assume that the input of. In practice variation of the three factors is used for speed 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. Direct current is applied to the armature by means of a carbon brush or by means of electromagnetic induction. Speed control of dc motor by using pwm technique project report. Jun 12, 2019 voltage control method of speed control of shunt dc motor in this method, we apply the variable input voltage to the motor to control its speed. Todays industries are increasingly demanding process automation in all sectors. 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. Initially, a thyristor will conduct switch on when the anode is positive with respect. This motor is used when both a high starting torque and good speed regulation is needed. 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. These curves are also known as performance curves of a motor. The dc motor converts the mechanical power into dc electrical power.

From the speed useful output power curve it is seen that the shunt motor has a definite speed at no load. Speed control of dc motor using pulse wi authorstream. Speed control of dc shunt motor with field and armature rheostat control 79 2. 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. The field of the shunt motor is supplied from a constantvoltage exciter e. Presentation on speed control and braking of dc shunt motor. Speed control of dc motor dc motor speed control youtube. Therefore speed of the 3 types of dc motors shunt, series and compound can.