International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) V...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) V...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) V...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 09766545(Print), ISSN 0976 – 6553(Online) Vol...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 09766545(Print), ISSN 0976 – 6553(Online) Vol...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) V...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 09766545(Print), ISSN 0976 – 6553(Online) Vol...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) V...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) V...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) V...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) V...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) V...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) V...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) V...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) V...
International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) V...
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A comparative analysis of speed control of separately excited dc motors by conventional 2

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A comparative analysis of speed control of separately excited dc motors by conventional 2

  1. 1. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME229A COMPARATIVE ANALYSIS OF SPEED CONTROL OFSEPARATELY EXCITED DC MOTORS BY CONVENTIONAL ANDVARIOUS AI TECHNIQUE BASED CONTROLLERSDebirupa Hore*(M.Tech Power and Energy systems, B.E Electrical Engineering)*Assistant Professor Electrical Engineering DepartmentKJ Educational Institutes” KJCOEMR Pune Maharashtra IndiaABSTRACTThis paper presents a comparison of speed control of a separately excited DC motorusing different types of controllers. Conventional controllers are generally used to control thespeed of the separately excited DC motors in various industrial applications. It is found to besimple and high effective if the load disturbances are small. But during high load or largevariation of load the AI technique based controllers such as proves to be fast and reliable. Tocontrol the speed of the motor a step down chopper is also used. The control scheme of themotor was tested with convention PI controller following the Fuzzy controller and thenANFIS Based speed controller. All the responses were analyzed in MATLAB/SIMULINKenvironment. The simulation results show that the Artificial Intelligence based speedcontrollers gives good performance and high robustness in large load disturbances.I.INTRODUCTIONDevelopment of high performance motor drives is very essential for industrialapplications. A high performance motor drive system must have good dynamic speedcommand tracking and load regulating response. Depending on the application, some of themhave fixed speed and some have variable speed. The variable speed drives, have variouslimitations such as poor efficiencies, lower speeds etc. With the advent of power electronicstoday we have variable drive systems which are not only smaller in size but also veryefficient, highly reliable and meeting all the stringent demands of the various industries ofmodern era. DC motors provide excellent control of speed for acceleration and deceleration.The power supply of a DC motor connects directly to the field of the motor which allows forINTERNATIONAL JOURNAL OF ELECTRICAL ENGINEERING& TECHNOLOGY (IJEET)ISSN 0976 – 6545(Print)ISSN 0976 – 6553(Online)Volume 4, Issue 2, March – April (2013), pp. 229-244© IAEME: www.iaeme.com/ijeet.aspJournal Impact Factor (2013): 5.5028 (Calculated by GISI)www.jifactor.comIJEET© I A E M E
  2. 2. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME230precise voltage control, and is necessary for speed and torque control applications. DCdrives, because of their simplicity, ease of application, reliability and favorable costhave long been a backbone of industrial applications. DC drives are less complex ascompared to AC drives system. DC drives are normally less expensive for low horsepowerratings. DC motors have a long tradition of being used as adjustable speed machines and awide range of options have evolved for this purpose. Cooling blowers and inlet air flangesprovide cooling air for a wide speed range at constant torque. DC regenerative drives areavailable for applications requiring continuous regeneration for overhauling loads. AC driveswith this capability would be more complex and expensive. Properly applied brush andmaintenance of commutator is minimal. DC motors can provide high starting torques whichis required for traction drives. They are also used for mobile equipment such as golf carts,quarry and mining applications. DC motors are conveniently portable and well fit tospecial applications, like industrial equipments and machineries that are not easily runfrom remote power sources.With the advent of thyristors and thyristor power converters the variable voltage tothe dc motor is obtained from static power converters. Phase controlled rectifiers providevariable dc voltage from constant voltage, constant frequency mains. The static apparatus isvery efficient, compact and has a very good dynamic behavior. It is very easy to provide afour quadrant drive with slight modifications in the converter. A dc chopper can be used toobtain a variable voltage from a constant dc voltage. The average value of the output voltagecan be varied by varying the time ratio of the chopper.II.CHOPPERSA DC chopper is a static power electronic device that converts fixed dc input voltageto a variable dc output voltage. A Chopper may be considered as dc equivalent of an ACtransformer since they behave in an identical manner. As chopper involves one stageconversion, these are more efficient. Choppers are now being used all over the world forrapid transit systems. These are also used in trolley cars, battery-operated vehicles, traction-motor control, and control of induction motors, marine hoists, forklift trucks and minehaulers. The future electric automobiles are likely to use choppers for their speed control andbraking. Besides, the saving in power, the DC chopper offers greater efficiency, fasterresponse, lower maintenance, small size, smooth control, regeneration facility and for manyapplications, lower cost, than motor-generator sets or gas tubes approaches.A. PRINCIPLE OF STEP-DOWN CHOPPER (BUCK-CONVERTER) OR CLASS ACHOPPERA chopper is a high speed ON or OFF semiconductor switch which is consists ofpower semiconductor devices, input dc power supply, elements (R, L, C, etc.) and outputload. The average output voltage across the load is controlled by varying on-period and off-period (or duty cycle) of the switch In fig.1 when chopper CH1 is ON, V0 = Vୱ and current i0flows in the arrow direction shown. When CH1 IS OFF, V0 = 0 but i0 in the load continuesflowing in the same direction through freewheeling diode FD. Hence average values of bothload voltage and current, i.e. V୭ and I0 are always positive as shown by the hatched area in thefirst quadrant of V୭-I୭ plane in fig.1 (b). The power flow in type-A chopper is always fromsource to load. This chopper is also called step-down chopper as average output voltage V0 isalways less than the input dc voltage.
  3. 3. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME231Fig. 1(a) Class A Chopper CircuitFig. 1(b): Voltage and Current DirectionsThe variations in on and off periods of the switch provides an output voltage with anadjustable average value.Fig 1(c): Voltage WaveformsAverage voltage, V୭ = (T୭୬ / (T୭୬ +T୭୤୤))* Vୱ= (T୭୬ /T)* Vୱ=αVୱ (1)T୭୬ = on-timeT୭୤୤ = off-timeT = T୭୬ + T୭୤୤= chopping periodThus the voltage can be controlled by varying duty cycle.V୭ = f*T୭୬ *Vୱ (2)f = 1/T = chopping frequencyIII. MODELLING OF SEPARATELY EXCITED DC MOTORA separately excited dc motor is very versatile as a variable speed motor. Its speed can bevaried by varying the applied voltage to the armature or field current. The speed control using thevariation of armature voltage can be used for constant torque application in the speed range fromzero to rated speed (base speed). Speeds above base speed are obtained by means of fieldweakening, the armature voltage being kept at the rated value. The speed control in this case is atconstant power. In both cases the speed control is smooth and step-less
  4. 4. International Journal of Electrical Engineering and Technology (IJEET), ISSN 09766545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, MarchFig 2Fig 2(b): CompleteA. OPERATION OF SEPARATELY EXCITED DC MOTORWhen a separately excitedcurrent of ia flows in the circuit, the motor develops a back EMF and a torque to batorque at a particular speed. The field current if is independent of the armature currentwinding is supplied separately. Any change in the armature current has no effect on the fieldcurrent. In general ia is much less thanB. FIELD AND ARMATURE EQUATIONSInstantaneous field current:difVf = Rf if + LfdtWhere, Rf and Lf are the field resisInstantaneous armature current:diaVa = Raia+La + EgdtWhere, Ra and La are the armatuThe motor back emf, which is also known as speed voltage, is expressed as:Eg = KvωifKv is the motor voltage constant (lectrical Engineering and Technology (IJEET), ISSN 09766553(Online) Volume 4, Issue 2, March – April (2013), © IAEME232Fig 2(a): Separately Excited DC motorComplete layout for DC motor speed controlOPERATION OF SEPARATELY EXCITED DC MOTORexcited dc motor is excited by a field current of if and anflows in the circuit, the motor develops a back EMF and a torque to batorque at a particular speed. The field current if is independent of the armature currentwinding is supplied separately. Any change in the armature current has no effect on the fieldis much less than if.FIELD AND ARMATURE EQUATIONS(3), Rf and Lf are the field resistor and inductor, respectively.(4)are the armature resistor and inductance respectively.The motor back emf, which is also known as speed voltage, is expressed as:(5)constant (in V/A-rad/sec and ω is the motor speed (in rad/sec).lectrical Engineering and Technology (IJEET), ISSN 0976 –April (2013), © IAEMEand an armatureflows in the circuit, the motor develops a back EMF and a torque to balance the loadtorque at a particular speed. The field current if is independent of the armature current ia.. Eachwinding is supplied separately. Any change in the armature current has no effect on the fieldin rad/sec).
  5. 5. International Journal of Electrical Engineering and Technology (IJEET), ISSN 09766545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, MarchC. BASIC TORQUE EQUATIONThe torque developed by the motor is:Td = Kt if iawhere, (Kt=Kv) is the torque constant.(in V/AFor normal operation, the developed torque must be equainertia, i.e.dωTd = J + Bω + TLdtWhere, B: viscous friction constant, (: load torque (N.m)J: inertia of the motor (kg.mD. STEADY-STATE TORQUE AND SPEEDThe motor speed can be easily derived:ω = (Va - IaRa)/KvIfIf Ra is a small value (which is usual), or when the mω = Va /KvIfThat is if the field current is kept constant, the motor speed depends only on the supply voltage.The developed torque is:Td = Kt If Ia = Bω + TLThe required power is:Pd= TdωE. TORQUE AND SPEED CONTROLAn important fact can be deduced for steadycurrent, or flux (If) the torque demand can be satisfied by varying the armature currentmotor speed can be controlled by controllingF. VARIABLE SPEED OPERATIONFig. 3(a): Torque Vs Speed Characteristiclectrical Engineering and Technology (IJEET), ISSN 09766553(Online) Volume 4, Issue 2, March – April (2013), © IAEME233BASIC TORQUE EQUATIONThe torque developed by the motor is:a (6)) is the torque constant.(in V/A-rad/s)For normal operation, the developed torque must be equal to the load torque plus the friction and(7), (N.m/rad/s)J: inertia of the motor (kg.m2)STATE TORQUE AND SPEEDThe motor speed can be easily derived:(8)If Ra is a small value (which is usual), or when the motor is lightly loaded, i.e. Ia is small,(9)That is if the field current is kept constant, the motor speed depends only on the supply voltage.(10)(11)TORQUE AND SPEED CONTROLdeduced for steady-state operation of DC motor. For a fixed fieldthe torque demand can be satisfied by varying the armature currentcontrolling Va (voltage control) or controlling Vf (field control).VARIABLE SPEED OPERATIONTorque Vs Speed Characteristic for Different Armature Voltageslectrical Engineering and Technology (IJEET), ISSN 0976 –April (2013), © IAEMEl to the load torque plus the friction andotor is lightly loaded, i.e. Ia is small,That is if the field current is kept constant, the motor speed depends only on the supply voltage.For a fixed fieldthe torque demand can be satisfied by varying the armature current Ia. The(field control).Different Armature Voltages
  6. 6. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME234Family of steady state torque speed curves for a range of armature voltage can be drawn as above. Thespeed of DC motor can simply be set by applying the correct voltage. The speed variation from noload to full load (rated) can be quite small. It depends on the armature resistance.G. BASE SPEED AND FIELD-WEAKENINGFig. 3(b): Torque Vs Speed and Power Vs Speed Characteristic of Separately Excited DC MotorThe motor speed can be varied by-(a) Controlling the armature voltage Vୟ, known as voltage control;(b) Controlling the field current I୤, known as field control; and(c) Torque demand, which corresponds to an armature current Iୟ, for a fixed field current I୤.The speed corresponds to the rated armature voltage, rated field current and rated armature currentwhich is known as the rated (or base) speed. In practice, for a speed less than the base speed, thearmature current and field currents are maintained constant to meet the torque demand, and thearmature voltage Vୟ is varied to control the speed. For speed higher than the base speed, the armaturevoltage is maintained at the rated value and the field current is varied to control the speed. However,the power developed by the motor (power = torque * speed) remains constant.Base speed (Wୠୟୱୣ)-The speed which correspond to the rated Vୟ , rated Iୟ and rated I୤ .Constant torque region (W< Wୠୟୱୣ)-Ia and If are maintained constant to met torque demand. Vୟ is varied to control the speed as powerincreases with speed.Constant power region (W> Wୠୟୱୣ)-Vୟ is maintained at the rated value and If is reduced to increase speed. However the powerdeveloped by the motor (= torque x speed) remains constant. This phenomenon is known as Fieldweakening.Fig 3(c): Typical Operating Regions of Separately Excited DC Machines
  7. 7. International Journal of Electrical Engineering and Technology (IJEET), ISSN 09766545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, MarchIV. DESIGN OF CONTROLLERThree types of controllers were usedinvolves the design of three types of controller1. Conventional PI Controller2. Fuzzy Controller3. ANFIS ControllerA. DESIGN OF PI CONTROLLER1. DESIGN CURRENT CONTROLLERFig4: Block diagram for dKtKp(1+Tis)*( RaIa Tis(1+sTa)=Iaref KtKp(1+Tis)*(Ra)Tis(1+sTa)Here, (Current Controller Parasuch that it cancels the largest time constant in tof the system in 7.2.and, the responseTi=TaNow, putting the value in equationIa KtKp/RasTa=Iaref K1KtKp/RaTas(1+T1s)KtKpLet Ko =RaTalectrical Engineering and Technology (IJEET), ISSN 09766553(Online) Volume 4, Issue 2, March – April (2013), © IAEME235CONTROLLERThree types of controllers were used and the result was analyzed. Design of Controllerinvolves the design of three types of controllerConventional PI ControllerDESIGN OF PI CONTROLLERCURRENT CONTROLLERBlock diagram for design of Current Controller)(12)K11+T1s(Current Controller Parameter) can be varied as when required. should be chosenlargest time constant in the transfer function in order to reduce orderof the system in 7.2.and, the response will be much faster. AssumingNow, putting the value in equation (12) we have(13)lectrical Engineering and Technology (IJEET), ISSN 0976 –April (2013), © IAEMEDesign of Controllershould be chosenhe transfer function in order to reduce order
  8. 8. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME236So,୍౗୍౗౨౛౜= I୅=୏౥/ୱଵା୏౥ేభ౩(భశ ౐భ౩)I୅=(ଵା ୘భୱ)୏౥ୱ²୘భ ା ୱା୏౥୏భ(14)Therefore, the characteristic equation of the above equation is given ass²Tଵ + s + K୭Kଵ =0s² +ୱ୘భ+୏౥୏భ୘భ=0s² + 2€ ω + ω ²=0; ω =ට୏౥୏భ୘భ€=1/(2Tଵ )=ଵଶඥ୏౥୏భ୘భFor a second order system value of €=0.707 to have a proper response.0.707=ଵଶඥ୏౥୏భ୘భK୭Kଵ =1/2Tଵ୏౪୏౦୏భ୘భୖ౗୘౗=ଵଶ(15)K୮ =ୖ౗୘౗ଶ୏భ୘భ ୏౪(16)From Eq.14 we haveI୅=ଵଶ୏భ୘భ‫כ‬(ଵା ୘భୱ)ୱ²୘భ ା ୱା୏౥୏భ)=(ଵା ୘భୱ)/୏భୱ²୘²భ ା ୱ୘భ ାଵ(17)The zero in the above equation may result in an overshoot. Therefore, we will use a time lagfilter to cancel its effect. The current loop time constant is much higher than filter timeconstant. For a small delay we can write(1 + Tଵs)I୅ =భశ ౐భ౩ేభୱమ୘²భ ା ୱ୘భ ାଵ(18)I୅=భేభୱమ୘²భ ା ୱ୘భ ାଵ(19)Neglecting s² term we haveI୅=భేభଵାଶ ୱ୘భ(20)This equation is used as a response for the speed controller.
  9. 9. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME2372. DESIGN OF SPEED CONTROLLERFig5: Block diagram for design of Speed Controllerω(s)/ሼω(s)(ref) = (Kn/K2)(Ra/KmTmTn)(1 + TnS/(1 + 2T2S)S²)/ሼ1 + (KnRa/K2KmTmTn)(1 +TnS/(1 + 2T2S)S²)(K1/(1 + T1S))ሽ (21)Here, we have the option to Tn such that it cancels the largest time constant of the transfer functionSo, Tn=2T2Hence, equation 21 will be written as:ω(s)/ω(s)(ref. ) = (KnRa/K2KmTmTn)(1 + T1S)/ሼK2KmTnS2(1 + T1S) + KnRaK1ሽ (22)Ideally, ω(s) =1/S (S²+αs+β)The damping constant is zero in above transfer function because of absence of S term, which results inoscillatory and unstable system. To optimize this we must get transfer function whose gain is close tounityThen using Modulus og Hugging method and deducing the above equation we finally get߱(‫/)݂()ݏ‬ሼ߱(‫)݂݁ݎ()ݏ‬ = 1/(‫1ܭ‬ + 4ߜ‫1ܭ‬ + 8‫1ܭߜ2ݏ‬ + 8‫)1ܭߜ3ݏ‬ (23)3. DESIGN OF FUZZY CONTROLLERThe fuzzy controller used in this scheme is a Speed Controller. The Conventional Speed PIController is replaced by a Fuzzy Logic Based speed Controller for providing more reliable controlleroutputs for the Speed control of The Induction Motor. The main objective of the fuzzy controller is thatthe actual speed response of the induction motor must track the reference speed response The design ofa Fuzzy logic system includes the design of a rule base, the design of the member-ship functionsdetermination of the Linguistic values. Here, the inputs of fuzzy controllers are the error in speed andthe rate of change of this error at any time interval. The output of the fuzzy controller is the ActivePower. Here, five fuzzy sets (NB, N, Z, P, and PB) are adopted for each input and output variables.The Character NB, N Z, P, PB represents Negative big, Negative, Zero, Positive, Positive Big. Themembership functions of the two input variables and the one output variable has normalized universeof discourse over the interval [- 1, 1].For the implementation of FLC, firstly, the universe of discourseof input and output variables of FLC are determined. In practice, each universe is restricted to aninterval that is related to the maximal and minimal possible values of the respective variables. That isto the operating range of the variable. The universe of discourse of the input and output variables of theMamdani type (PI like) FLC can be determined as-The universe of the error is defined by the maximal and minimal values of the variables. It {emin,emax] is the interval where:݁௠௔௫ = ܹ௠௔௫ െ ܻ௠௜௡݁௠௜௡ = ܹ௠௜௡ െ ܻ௠௔௫
  10. 10. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME238Analogously the change in error and the change of the output have operating ranges between[∆݁௠௜௡,∆݁௠௔௫] and [∆‫ݑ‬௠௜௡,∆‫ݑ‬௠௔௫].Where,` ∆݁௠௔௫ = ݁௠௔௫ െ ݁௠௜௡∆݁௠௜௡ = ݁௠௜௡ െ ݁௠௔௫∆‫ݑ‬௠௔௫ = ‫ݑ‬௠௔௫ െ ‫ݑ‬௠௜௡∆‫ݑ‬௠௜௡ = ‫ݑ‬௠௜௡ െ ‫ݑ‬௠௔௫The operating ranges are defined with respect to the external values of the relevant variables. Theycan be further adjusted by taking into account the dynamics of the controlled systems and thesampling intervals.For simplification and unification of the design of the FLC and its computer implementation,however it is more convenient to operate with normalizes universe of discourse of the input andoutput variables of the FLC. The normalized universes are well defined domains; the fuzzy valuesof input and output variables are fuzzy subsets of these domains. In general, the normalizeduniverses can be identical to the real operating ranges of the variables, but in most applicationsthey coincide with the closed interval [-1 1].Otherwise ,scaling of both input and output variablesare done in order to bring the values within prescribed limit.The Rule Table is formulated based on which the Fuzzy Controller is designed.Table:1 Rule base for speed controller4. DESIGN OF ANFIS CONTROLLERSteps Involved in the making of the ANFIS ControllerStep1: Get the Error and Change in Error values from the previous model and save it in workspaceand finally define these values in a matrix in the M-file of Matlab.Step2: Run the matrix file.Step3: Open the ANFIS editor.Step4: Load data from workspace in the ANFIS editor.Step5:Generate FIS using Grid Partition. Here, the number of Member Functions and type ofMember Functions are taken.Step6: Train the data using training FIS. Here the Error tolerance and epochs are also given.Step7: The data is trained using Train FIS.Step8: Step2 to 7 are performed using Checking Data.Step9: The file is saved in both workspace and matlab-file by exporting it.Step10: The Simulink model for ANFIS is opened and the controller is named after the name ofthe file saved in Step9.The ANFIS Speed Controller is obtained using the above steps.
  11. 11. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME239V. SIMULATION RESULTS AND DISCUSSIONSThe graph responses of the Fuzzy and ANFIS controllers has been compared with the.conventional PI controller. With the implementation of AI techniques (Fuzzy ANFIS), theresponse shows that there is much flexibly with the variation of load found as compared toconventional model. In all the responses it has been found that the actual speed of the DCmotor is as par with the reference speed of the motor. With Conventional PI speed controllerthe actual speed of the motor is tracking the reference speed of the motor up to the ratedspeed and even beyond it. But with Fuzzy ANFIS Controller the actual speed of the motoris tracking the reference speed of the motor upto the rated speed and when the motor isoverloaded the responses falls and error goes on increasing concluding that the motors fails tostart or the motor stops. Thus the AI technique based controllers provides much better andprecise control of the DC motor.FIG 6:-Block Representation of Motor Model with Fuzzy PI ControllerFig 7:-Block Representation of Motor Model with ANFIS PI Controller
  12. 12. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME240AppendixTable:2I. Performance of DC motor using PI speed ControllerIt is observed from the responses that the actual speed of the DC motor tracks the referencespeed of the motor up to the rated speed of the motor (55rpm). Beyond the rated speed the PIcontroller has limitations in controlling the speed of the dc motor.Fig 8: Speed Responses of a Separately Excited dc Motor with Step Source as Input Using PIControllerFig 9: Speed Responses of a Separately Excited dc Motor with Ramp Source as Input UsingPI Controller0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-200204060Reference SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-200204060Actual SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-200204060Error SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060Reference SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060ActualSpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-0.500.51Error SpeedTime in SecSpeedinrpm
  13. 13. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME241II.Performance of DC motor using Fuzzy speed ControllerA. With motor running up to rated speedFig 9: Speed Responses of a Separately Excited dc Motor with Step Source as Input withRated Load Using Fuzzy ControllerFig10: Speed Responses of a Separately Excited dc Motor with Ramp Source as Input withRated Load Using Fuzzy Controller0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060ReferenceSpeedTimeinSecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060ActualSpeedTimeinSecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060ErrorSpeedTimeinSecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060ReferenceSpeedTimeinSecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060ActualSpeedTimeinSecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-0.500.51ErrorSpeedTimeinSecSpeedinrpm
  14. 14. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME242B. With motor running at overloaded conditionFig 11: Speed Responses of a Separately Excited dc Motor with Step Source as Input withOver Loading Condition Using Fuzzy ControllerFig 12: Speed Responses of a Separately Excited dc Motor with Ramp Source as Input withOver Loading ConditionIII. Performance of DC motor using ANFIS based speed ControllerA. With motor running up to rated speedFig 13: Speed Responses of a Separately Excited dc Motor with Step Source as Input withRated Load Using ANFIS Controller0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060Reference SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-400-2000Actual SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50100200300400500Error SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5050100Reference SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-400-2000Actual SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50100200300Error SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060Time in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060Time in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060Time in SecSpeedinrpmActual SpeedError SpeedReference Speed
  15. 15. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME243Fig 14: Speed Responses of a Separately Excited dc Motor with Ramp Source as Input withRated Load Using ANFIS ControllerB. With motor running at overloaded conditionFig 15: Speed Responses of a Separately Excited dc Motor with Step Source as Input withOver Loading Condition Using ANFIS ControllerFig 16: Speed Responses of a Separately Excited dc Motor with Ramp Source as Input withOver Loading Condition Using ANFIS Controller .0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060Reference SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060ActualSpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060Error SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060Reference SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-60-40-200Actual SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5050100ErrorSpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50204060Reference SpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5-200-1000ActualSpeedTime in SecSpeedinrpm0 0.5 1 1.5 2 2.5 3 3.5 4 4.50100200ErrorSpeedTime in SecSpeedinrpm
  16. 16. International Journal of Electrical Engineering and Technology (IJEET), ISSN 0976 –6545(Print), ISSN 0976 – 6553(Online) Volume 4, Issue 2, March – April (2013), © IAEME244VI.CONCLUSIONIn this paper the speed of a dc motor has been done using three different types ofControllers viz Speed PI controller, Fuzzy logic based controller and ANFIS based controller.The responses of the motor with three different types of controllers are simulated and studiedand compared with step and ramp responses. With varying load responses it is observed thatthe AI technique based controllers’ gives a flexible and precise control of speed both onnormal loaded and overloaded condition as compared to the conventional PI controller.REFERENCES[1].Waleed I. Hameed1 and Khearia A. Mohamad2” Speed control of separately excited dcmotor using fuzzy neural model reference controller” International Journal of Instrumentationand Control Systems (IJICS) Vol.2, No.4, October 2012 PP 27-39.[2] Dr.P.S Bimbhra “Power Electronics”,Khanna Publishers.[3]Ronald R Yager, Dimitar P Filev, “Essentials of Fuzzy Modeling and Control “WileyInterscience Publications.[4]Jun Yan, Michael Ryan, James Power “Using FuzzyLogic towards Intelligent systems”[5]Singari.v.s.r Pavankumar, Sande.krishnaveni, Y.B.Venugopal, Y.S.Kishore Babu, “ANeuro- Fuzzy Based Speed Control of Separately Excited DC Motor”, IEEE Transactions onComputational Intelligence and Communication Networks, pp. 93-98, 2010.[6] Basma A. Omar, Amira Y. Haikal, Fayz F. Areed, “An Adaptive Neuro-Fuzzy SpeedController for a Separately excited DC Motor”, International Journal of ComputerApplications, pp. 29-37, Vol. 39 No.9, February 2012.[7] Vandana Jha, Dr. Pankaj Rai and Dibya Bharti, “Modelling and Analysis of Dc-DcConverter Using Simulink for Dc Motor Control”, International Journal of ElectricalEngineering Technology (IJEET), Volume 3, Issue 2, 2012, pp. 58 - 68, ISSN Print : 0976-6545, ISSN Online: 0976-6553.[8] M.Gowrisankar and Dr. A. Nirmalkumar, “Implementation Simulation of Fuzzy LogicControllers for the Speed Control of Induction Motor and Performance Evaluation of CertainMembership Functions”, International Journal of Electrical Engineering Technology(IJEET), Volume 2, Issue 1, 2011, pp. 25 - 35, ISSN Print : 0976-6545, ISSN Online: 0976-6553.BIBLIOGRAPHYDebirupa Hore was born in Guwahati Assam India on April 19th1983.Shereceived her B.E Degree in Electrical Engineering from Assam EngineeringCollege Guwahati in 2006 and M.Tech in Energy and Power Systems in 2010from NIT Silchar. She worked in GIMT Guwahati for 5 years as AssistantProfessor. Currently she is working as an Assistant Professor in ElectricalEngineering Department in KJ Educational Institutes, KJCOEMR, Pune(Maharashtra).Her research areas of interest includes Power Systems, AITechniques, Power Electronics and Drives etc.

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