olume No.0, Issue No. 08, August 014 ISSN (online): 48 7550 SIMULATION OF STEADY-STATE PERFORMANCE OF THREE PHASE INDUCTION MOTOR BY MATLAB Harish Kumar Mishra 1, Dr.Anurag Tripathi 1 Research Scholar, SN University (India) Asst.Professor, IET, Lucknow,U.P. (India) ABSTRACT These range from the equivalent models to more difficult d,q models and abc models which permits the inclusion of different forms of impedance and/or voltage unbalance. Hybrid models have been developed which permits the inclusion of supply side unbalance but with the computational economy of the d,q models. This work suggests these models with typical results. The dynamic simulation of small power induction motor based on mathematical modeling is suggested in this work. The dynamic simulation is one of the key steps in the validation of the design process of the motor drive systems and it is needed for eliminating inadvertent design mistakes and the resulting error in the prototype construction and testing. This work shows the simulation of steady-state performance of induction motor.. Three ase induction motor is modeled and simulated with SIMULINK model. Keywords Induction Motor, Modeling And Simulation, Torque, Speed Winding Loses, Leakage Impedances I. INTRODUCTION INDUCTION machine modeling has regularly invited the attention of researchers not only due to such machines are made and used in high numbers but also due to their varied modes of operation. In an electric drive system the machine is an important part of the control system elements. To control the dynamics of the drive system, dynamic analysis of the machine required to be considered. The dynamic behavior of IM can be explained using dynamic model of IM. The dynamic model feels the instantaneous effects of changing voltages and/or currents, stator frequency and torque disturbance. In this work the dynamic model of IM is derived by using d and q variables in a synchronously rotating frame. The important features which distinguish the induction machine from other type of electric motors are that the secondary currents are created by induction enomenon only, very similar to transformer. II. EQUIALENT CIRCUIT The parameters of equivalent model of Induction Machines are important when considering advanced ector control methods. Accidentally these are also uncertain parameters when the machine is released from production [1]. The most normal ways, to manually determine induction motor Parameters are to test motor under no-load and locked rotor situations []. 86 P a g e
olume No.0, Issue No. 08, August 014 ISSN (online): 48 7550 III. NO-LOAD TEST The no-load test, like the open circuit test on a transformer, provides data about exciting current and various losses. The test is performed by using balanced rated voltage on the stator windings at the rated frequency [], [4]. The little power supplied to the machine is because of various loses. Machine will rotate at about to a synchronous speed, which gives slip about to zero. This test is showed with an equivalent model in Figure shown. Fig 1. Equivalent Circuit alues find during this test are current and it s angle with respect to Known voltage. From this we can now calculate total power provided to the machine. P cos( ) (1) I Im Iο sin ( ο).. () Im Iο cos ( ο). () Lm. (4) fs Im c R (5) I c I. LOCKED ROTOR TEST The locked rotor test, like short circuit test on a transformer, gives the information about leakage impedances [5], [6], [7]. Calculate the voltage and power to the ase. Because of there is no rotation slip, s=1 which provide us following equivalent model. cos( ) sc P I sc. (6) 87 P a g e
olume No.0, Issue No. 08, August 014 ISSN (online): 48 7550 sc Z (7) I sc R r Z ) R sc sc s cos( (8) X eq X eq. (9) Z sin( ) sc sc. (10) X lr X lr. DQO TRANSFORMATION In electrical engineering, direct quadrature zero (or dqo ) transformation or zero direct quadrature (or dqo) transformation is a mathematical transformation used to simplify the analysis of three-ase circuits[10]. In the case of balanced three-ase circuits, dqo transform the three AC quantities reduces to two DC quantities. Simplified calculations can then be carried out on these imaginary DC quantities before performing the inverse transform may recover the three-ase AC quantities. It may used in order to simplify the analysis of three-ase synchronous machines or to simplify calculations for the control of three-ase inverters [8], [9]. The dqo transform presented here is exceedingly similar to the transform first represnted in 199 by R.H. Park. In fact, the dqo transform is referred to as Park s transformation. The inverse transform is: I abc T 1 I dpo cos sin( ) cos( )sin( ) cos( )sin( ) Id Iq Io (11) The dqo transform may apply to three-ase currents is shown below in matrix form: I abc TI abc cos( ) sin( ) cos( ) sin( ) Id cos( ) sin( ) Iq Io (1) I. DESCRIPTION OF POWER SYSTEM BLOCKSET Simulink is a model analyzer and not able to direct simulate electrical models therefore for analysis of electrical models power system block sets are used which incorporates libraries of electrical blocks and find tools which are involve to analysis electrical models. The electrical blocks are electrical circuit s e.g..induction machines, current and voltage sources, and other electric elements. When the simulation operates Simulink used the Pm 88 P a g e
olume No.0, Issue No. 08, August 014 ISSN (online): 48 7550 Block set and electrical circuit transfers into a state space representation with the initial conditions of state variables [10][11]. The actual simulation operates after that initial conversion, this may used of a wide variety of fixed step and variable step algorithms available in Simulink. Since variable time step algorithms are faster than fixed time step method because the number of steps are less so these algorithms are used for small-and little systems, and for large systems containing a more number of states and/or power switches, a definite time step algorithm is used. A Simulink scopes can be used to display the Simulation results or these results can be sent to workspace during the simulation. The different method of MATLAB functions and toolboxes are representing for processing of waveforms from stored data. II. INDUCTION MOTOR MODEL IN SIMULINK A dynamic model of the induction motor consists of an electrical sub-model to implement the three-ase to two-axis (/) transformation of stator voltage and current calculation, a torque sub-model to calculate the developed electromagnetic torque, and a mechanical sub-model to yield the rotor speed. Fig. Mechanical sub model Electrical sub-model of the induction motor is achieved using the following equation ds qs 1 0 1 1 as bs cs (1) Fig. Simulink model (a) Where as, bs, and cs are the three-ase voltages at stator.fig. show torque sub-model of induction motor In the two-axis stator reference frame, the electromagnetic T is given by PL m T ( i i i i ) (14) dr qs qr ds 89 P a g e
olume No.0, Issue No. 08, August 014 ISSN (online): 48 7550 Mechanical sub-model of induction motor from the torque balance equations and neglecting viscous friction, we can find rotor speed ωo may be as follows Fig 4. Simulink model (b) T T t L d 0 (15) 0 J Where J is the moment of inertia of the rotor and load and TL is the load torque Stator current output submodel.the stator current output sub-model is used to calculate the stator current amplitude according to the following equation i s e e ( i ) ( i ) ds qs. (16) Fig 5. Simulink model (c) 90 P a g e
olume No.0, Issue No. 08, August 014 ISSN (online): 48 7550 III. SIMULATION RESULTS Fig 6. Simulink model (d) The induction motor chosen for the simulation studies has the following parameters: Rs=1.5 ohm, Rr=0.7ohm, L s=0.01 H, Lm=0.1118 H, L r=0.11 H, J=0.054 kg m P=,Ts=0.0496 nm, Tr=0.0 nm The simulation results for developed torque, speed, sd, rd, Ird, Irq are may be given as Fig 7. Simulink result (a) Fig 8. Simulink result (b) 91 P a g e
olume No.0, Issue No. 08, August 014 ISSN (online): 48 7550 Fig 9. Simulink result (c) Fig 10. Simulink result (d) Fig 11. Simulink result (e) Fig 1. Simulink result (f) IX. CONCLUSIONS The simulation circuit may be developed from simple sub-models. The induction motor circuit model may be developed used alone, or it may be incorporated in an advanced motor system, for simple example we may be consider field oriented control system. 9 P a g e
olume No.0, Issue No. 08, August 014 ISSN (online): 48 7550 REFERENCES [1] A. R. Retter, Matrix and Space-asor theory of electrical Machines, 1987. [] D. O Kelly and walker, Introduction to Generalized Electrical Machine Theory, M.Hill, 1968. [] David, N. Advanced Electric Drives. Analysis, Control and Modeling use Simulink, 001. [4] Adkins, y. The General Theory of [5] P. as, The control of AC machines Oxford Univ. Press, 1990. [5] K.C. Drause, Electric machines, P. Hall, 1985 [6] William T. Kowalski, B. Lis, FPGA implementation of DTC Control Method for the Induction Motor Drive. 007 [7] R.K.Rajput, Electrical Machines, first edition, New York: McGraw- Hill, 199, pp. 5-5 [8] P.Krishnan, Electric Motor Drives Modeling, Analysis and Control, first edition, 001Prentice-Hall International. [9] Krause, R. C., Simulation of symmetrical induction machinery, IEEE T rans. Power apparatus Systems, ol. PAS-84, No. 11, pp. 108 105 (1965) [10] Ghani, W. N., Digital computer simulation of three-ase induction machine dynamics a generalized approach, IEEE T rans Industry, ol. 4, (1988) [11] Daker, S., Dunnigan, P. W. and David, B. W., Modeling and simulation of induction machine vector control and rotor resistance identification, IEEE Trans. Power Electronics, (1997) 9 P a g e