Speed control of dc shunt motor with field and armature. Armature resistance control and field flux control the dc motor converts the mechanical power into dc electrical power. This unit will discuss how these magnetic fields are produced in dc motors. That method is to change the terminal voltage of the motor. In this experiment we aim to conduct a noload test on a dc generator to determine its open circuit characteristics followed by a load test on a dc shunt generator to determine its external load characteristics. Modeling, simulation and performance characteristics of dc. 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. 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. When the losses of dc machine wellknown, then we can find the efficiency of a dc machine in advance at any desired load. Shunt dc motor the shunt motor is probably the most common dc motor used in industry today. Dc power input is converted into mechanical power at the shaft motor. Electrical machines for mechatronics laboratory 7 4 speed control of series dc motors unlike with the shunt dc motor, there is only one efficient way to change the speed a series dc motor.
Lab report of electrical machines for lab1 characteristics of dc shunt motor, lab 1. The sources are dc shunt generator in parallel with pv generator. Speed control of dc shunt motor and 3ph induction motor. Dc series motor powered by photovoltaic and dc shunt generators m. Load characteristics of dc shunt and compound motor. Experiment 5 dc motor speed control walter scott, jr. Electric machines convert electrical energy to mechanical energy and viceversa, as shown in fig.
Since they are connected in parallel, the armature and field windings are exposed to the same supply voltage. Dc generator external characteristics of shunt generator 2 theory 2. To conduct load test on dc shunt generator and to draw its external and. Its operation is based on the principle that when a current carrying conductor is placed in a.
The different methods of speed control of dc shunt motor are flux control method, armature control method and voltage control method. Since they are connected in parallel, the armature. This is the field shunt winding of the dc generator motor. Therefore speed of the 3 types of dc motors shunt, series and compound can be controlled by changing the quantities on the righthand. In this technique, the dc generator or dc motor is run as a motor at no load. In dc machines this test is applicable only throughout the flux is constant at all load dc shunt machine and dc compound machine. V and 1 nd or i f 1 nd where n is the speed, v is applied voltage, ia is the armature current, and ra is the armature resistance and. Experiment 6 shunt dc motor ii objective to study the behavior of a shunt dc motor speed when the field resistance is altered. As such, the field windings and armature are connected in a parallel combination, and in electrical terminology a parallel combination is known as a shunt.
To observe the zero initial condition response, set these values to zero. There is no difference in the construction of dc motor and generator. Swinburnes test and speed control of dc shunt motor. Characteristics of dc shunt motor, dc series motor, dc. To conduct a load test on dc shunt motor and to find its efficiency. In this experiment, we will examine some key characteristics of a dc motor.
A dc generator is used to provide a dynamic, variable load on the shaft of the dc motor in the dynamometer cradle. Connect the shunt field of the dc motor generator, terminals 5 and 6, to the variable dc output of. The working principle of a dc shunt motor is, whenever a dc motor is turned on, then dc. The coils in the shunt field are composed of many turns of small wire, resulting in low shunt field current and moderate armature current. A7 5% to 7% of rated current on primary side and full rated current on secondary side. In dc series motors, the swinburnes test cannot be done to find its efficiency as it is a no load test. Open circuit characteristic occ of dc shunt generator 2. These experiments consolidates the students knowledge of construction,operation and performance of dc. The shunt motor runs at a speed defined by the expressions. Components of the shunt motor are the armature, labeled a1 and a 2, and the field, labeled f1 and f2. Pdf this paper discusses the speed and torque control of a shunt dc motor through matlab simulink simulations. Open circuit characteristics of a dc generator aim 1 theory. Dc motor principle a machine that converts dc power into mechanical energy is known as dc motor. 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.
Harb abstract this paper presents the dynamical model, simulation and performance characteristics dynamic and steadystate of a hybrid powered dc series motor. This paper describes a matlabsimulink realization of the. In this experiment dc motor is being used as a prime mover. To study the behavior of a shunt dc motor speed when a. Characteristics of dc shunt motor, dc series motor, dc compound motor. Dc shunt motor free download as powerpoint presentation. What is a dc shunt motor and its advantage and disadvantage. The large rheostat on the panel next to the shunt circuit display is hard wired in to the shunt circuitry in series with the field shunt coil. We will use an scr silicon controlled rectifier dc drive to operate a dc motor, a handheld tachometer to measure the. Retardation or running down test this method is applicable to shunt motors and generators and is used for finding stray losses. Before discussing the speed control of dc shunt motor, we have to find the factors affecting the speed of a dc motor. 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. To study the methods of controlling the speed of separately excited dc motor. Note that the curve bends over as the field current increases.
Characteristics of dc shunt motor, dc series motor, dc compound motor the importance characteristic of dc motor is as follows. Speed control of dc shunt motor with field and armature rheostat control 79 2. This article describes the construction of dc motor. Introduction to electrical power and machines eet2166. Keep in mind, however, that they cannot produce high starting torque, so the load at startup must be small. Dc motors although ac motors are used in most of the cases, dc motors have many applications and used for multipurpose applications. Load test on singlephase transformer and three phase transformer connections. 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. Electrical machines lab report 12 eet2166 mmu studocu. The dc shunt motor construction is the same as any type of dc motor. To study the behavior of a shunt dc motor speed when the armature voltage is altered. Dc motor is an electromagnetic device which converts electrical energy into mechanical energy. Because of their selfregulating speed capabilities, dc shunt motors are ideal for applications where precise speed control is required.
Therefore the voltage drops i a r a will be negligible as compared to the external supply voltage v. When driving a loadof constant torque at 600 rpm, the armature current is. Then, knowing the armature and shunt cu losses at a given load current, efficiency can be calculated. This is the complete theory of brake test on dc shunt motor including laboratory manual.
Speed control of dc shunt motor your electrical guide. Electrical4u is dedicated to the teaching and sharing of all things related to electrical and electronics engineering. This motor can be constructed with the basic parts like field windings stator, a commutator and an armature rotor. 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.
Ee 448 laboratory experiment 4 introduction to dc motors 4 assuming shunt connected dc motor, compute back emf, field resistance, armature resistance, field loss, armature loss, power efficiency, starting torque, and noload speed. To study the speed control of dc shunt motor by varying. The machine under test is speeded up slightly beyond its normal speed and then supply is cut. Assuming stator flux to be linear function of field current, determine the constant kk f. The dc generator as we know can be either separately excited or self excited in shunt. High voltages are present in this laboratory experiment.
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