An SMC based RZVDPWM Algorithm of Vector Controlled Induction Motor Drive for Better Speed Response with Reduced Acoustical Noise

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1 ISSN: , Volume-6, Issue-1, Octobe 016 An SMC based RZVDPWM Algoithm of Vecto Contolled Induction Moto Dive fo Bette Speed Response with Reduced Acoustical Noise M Veea Chanda Kuma, K. Satyanaayana, M.N.V.V. Bahmam Abstact: In this pape, an sliding mode contolle (SMC) based Random Zeo vecto Distibution PWM (RZVDPWM) algoithm of vecto contolled induction moto dive fo bette speed esponse with educed Acoustical Noise is analyzed. In ode to mitigate the difficulty faced in the conventional Space Vecto PWM (SVPWM) appoach, the poposed RZVDPWM algoithm is ceated by taking the concept of Simplified PWM sequence. This algoithm is developed by using the concept of andom numbe geneation technique. Simulation studies ae caied out to validate poposed RZVDPWM algoithm, the esults obtained ae pesented and compaed. The simulation esults shows that the oveall pefomance of SMC based RZVDPWM dive is bette when compaed to SVPWM technique unde diffeent conditions of opeation. Index Tems: Simplified PWM sequence, SVPWM, RZVDPWM, Vecto contol, SMC I. INTRODUCTION The voltage souce invete fed induction moto dives give moe hamonic distotion. The hamonic distotion can be educed by going in fo moe complex topologies like multilevel invetes, etc. Altenatively, it is possible to achieve an impoved pefomance even with a two-level invete by designing suitable high-pefomance PWM algoithms. Nowadays, the vaiable speed dives ae most pominently being used fo industial applications. The ceation of vecto contol algoithm has bought evolution in the high-pefomance vaiable speed dives. The vecto contol o field oiented contol (FOC) algoithm enables the isolating contol of toque and flux of an asynchonous moto dive. Using this vecto contol, the asynchonous moto can be otated in the pemissible limits like a sepaately excited dc moto [1]. Anyways, the classical vecto contol algoithm consides the hysteesis contolles that poduce vaiable switching fequency opeation of the invete. To obtain consistent switching fequency opeation, the space vecto PWM (SVPWM) algoithm is consideed in vecto contolled Revised Vesion Manuscipt Received on Septembe, 016. M. Veea Chanda Kuma, Depatment of Electical and Electonics Engineeing, Pagati Engineeing College, Suampalem, East Godavai, (A.P). Inida. D. K. Satyanaayana, Depatment of Electical and Electonics Engineeing, Pagati Engineeing College, Suampalem, East Godavai (A.P). India. M. N.V.V. Bahmam, Depatment of Electical and Electonics Engineeing, Pagati Engineeing College, Suampalem, East Godavai (A.P). India. asynchonous moto dives. The standad SVPWM algoithm consides zeo state time distibution equal of both the zeo vectos, and giving constant switching fequency opeation []. Although SVPWM appoach gives bette pefomance compaed to classical algoithms it also poduces acoustical noise and hamonic distotion. In ode to minimize the acoustical noise poduced by the poposed SVPWM appoach, numeous andom PWM (RPWM) algoithms ae intoduced and ae pesented in liteatue [3]-[5]. RPWM algoithms family is shown in [3]. A andom pulse position PWM algoithm is pesented in [4] to minimize the acoustical noise. A andom pulse position PWM appoach is given in [4] to minimize the acoustical noise. A pat of the RPWM appoach is given in [5] which andomizes the sampling time peiod. The pevious RPWM algoithms makes use of classical space vecto algoithm, which needs the angle and secto data to build the efeence voltage vecto at each sampling time peiod. To minimize difficulty in the SVPWM algoithm, a new potential diffeence modulation algoithm is given in [6] by consideing the theoy of offset time. In ode to mitigate the difficulty of Space Vecto PWM algoithm, a new concept of simplified PWM sequence is given in [7]-[8]. The details of SMC based induction moto with Conventional methods like Popotional Integal (PI) with simulations esults pesented in [9]. In this pape, a sliding mode contolle (SMC) based Random Zeo vecto Distibution PWM (RZVDPWM) algoithm of vecto contolled asynchonous moto dive fo bette speed esponse with educed Acoustical Noise is analyzed. The poposed RZVDPWM algoithm poduces gating pulses by the efeence voltages which ae sampled. Hence it mitigates the difficulty which is pesented in the conventional SVPWM appoach. II. SVPWM ALGORITHM Voltage souce invetes (VSI) ae used in numeous applications. The 3-Ø, -level VSI has a basic fomat and poduces a low-fequency yields output voltage with allowable amplitude and fequency by pogamming highest-ecuing gate pulses. Fo a 3-Ø, -level VSI, 8 voltage vectos ae obtained, and ae epesented in Fig. 1. Fom these eight voltage vectos, V 1 to V 6 vectos ae known as active states o voltage vectos and the emaining two vectos ae known as zeo voltage vectos o zeo states. The sample voltage o efeence voltage space vecto which is shown in Fig. 1 also depicts the desied value coesponding

2 An SMC based RZVDPWM Algoithm of Vecto Contolled Induction Moto Dive fo Bette Speed Response with Reduced Acoustical Noise to it of the fundamental components fo the output phase voltages. In an aveage manne the space vecto appoach can be constucted. At equal intevals of time the efeence voltage vecto ( V ef ) is sampled, is used to denote the sampling time peiod. Vaious vectos of voltage which can be geneated by VSI ae given at vaious time peiods with time peiod of sampling ( ) so that the aveage vecto geneated on the efeence voltage V ef, both in magnitude and angle. So, in ode to get any of the sampled efeence voltage V ef the vecto which ae to be consideed ae both the Zeo state vectos and active state vectos thus foming a bounday of the secto in which the sample is pesent. All the sectos which ae specified in the Fig. 1 ae symmetical. The fist secto explanation is only given in the pape. III V4 (011) V3 (010) V 7 (111) IV V 0 (000) II T V V (110) V ef α T 1 VI V 5 (001) V 6 (101) I V 1 (100) Fig. 1 The Possible voltage space vectos and secto definition in SVPWM algoithm Fo the obtainable efeence voltage vecto V ef, the zeo and Active voltage vecto times can be calculated as given by (1), () and (3). sequence is in the same way to the instantaneous phase voltages and is fomulated as follows [7]: V an, V bn and V cn ae the instantaneous efeence phase voltages and T an, T bn and Tcn ae the elated Simplified PWM sequence. As these times ae popotional to instantaneous potential diffeences, these times can be negative whee voltages ae negative. Hence, these times ae given identification as Simplified PWM sequence. The active vecto switching times T 1 and T, if the efeence potential diffeence vecto V ef comes in I secto and can expessed as [7]-[8]: When the efeence potential vecto V ef comes in the fist secto, the switching time which is imaginay is popotional to a-phase (T an ) has a maximum value, the switching time which is imaginay coesponding to c-phase (T cn ) has a minimum value and the switching time which is imaginay coesponding to b-phase (T bn ) has a neithe minimum no maximum value in the conventional SVPWM appoach. So, in ode to calculate the active vecto switching times, the minimum ( T min ), middle ( T mid ) and maximum ( T max ) values of Simplified PWM sequence in evey sampling time ae calculated. Such that the active vecto switching times T 1 and T ae expessed as The zeo voltage vectos switching time is calculated as (4) (5) (6) b. Poposed Random Zeo Vecto Distibution Algoithm: (7) Whee M i is modulation index and is pesented in [1]. In the Space Vecto appoach, the total zeo state time is divided equally between V 0 and V 7 and is distibuted symmetically at stat and at the end of the each sampling time peiod. Thus, the patten used in SV appoach is in the fist secto, in the second secto and so on. III. PROPOSED RZVDPWM ALGORITHM a. Modified PWM sequence: Angle calculation and the tansfomation of efeence fames ae widely used in standad SVPWM appoach. So, the difficulty is obseved and is inceased in the standad SVPWM algoithm. Fo geneation of the gating times, the poposed RZVDPWM algoithm uses sampled efeence phase voltages which ae instantaneous. In view of explanation of poposed algoithm the basics of simplified PWM sequence will be intoduced. The Simplified PWM T z T T z T z 1 T T T 1 Fig. (a) Gating times in fist-secto of SVPWM algoithm T z 3

3 ISSN: , Volume-6, Issue-1, Octobe 016 Whee B a =, J 1 b = and J T J d L =. By Consideing the equation (1) with distubances as (11) (1) a, b and d epesents the distubances o uncetainties of the tems a, b and d espectively intoduced by system paametes J and B. Futhe, consideing the eo of speed tacking as given in (13) δ T T 1 T T T z 1 δ Tz Fig. (b) Gating times in fist-secto of modified RZVDPWM algoithm In the standad SVPWM algoithm the total zeo state vecto time is distibuted equally in between the both the zeo voltage vectos. But, the modified andom zeo vecto distibution PWM (RZVDPWM) algoithm distibutes the zeo state time between the two zeo voltage vectos as given in (8) and (9). T0 = δt z (8) T 7 = (1 δ )T z (9) δ is a numbe which is picked in andom manne. Its value anges fom 0.1 to 1 (i.e., 0% to 100%). Also, its value is less than one. The ode and gating times of applications of active and zeo state vectos in the secto-i ae as shown in the Fig.. In Fig., the conventional and the poposed algoithm gating times ae shown. As shown in the Fig., the poposed algoithm appoach of RZVDPWM andomizes the time of the zeo voltage vectos in evey sampling time inteval but, the pulses ae cente aligned as in standad SVPWM algoithm. c. Sliding mode contolle A sliding mode contol (SMC) which is basically an adaptive contol that gives solid pefomance of a dive with paamete vaiation and load toque distubance. In SMC the Induction moto dive esponse is foced to tact sliding along a pedefined efeence model in a phase plane by a switching contol algoithm, paamete vaiation and load distubance. The design and implementation of smc is simple. SMCS applied induction motos, sevo with dc motos, synchonous motos such as contolling of machine tools, obots etc. The electomechanical equation of induction moto is descibed as (10) Whee J is moment of inetia constant and B is the viscous fiction coefficient of the induction moto dive, T L is load toque, T e is the electomagnetic toque of induction moto ω and m is the mechanical speed of the oto in angula fequency, which is elated to oto electical speed by ω ω m =. P ( 1 δ )T z The electomechanical equation can be modified futhe as ωm (13) Hee is the command of efeence speed of the oto in angula fequency. Then, by taking the diffeentiation of (13) with espect to time gives, (14) Whee the following tems have been collected in the signal f(t), And the x(t), lumped uncetainty, defined as (15) (16) Now, the sliding vaiable with integal component can be defined as (17) Hee h is the gain constant. To obtain the tacking of speed tajectoy the following assumptions ae made Assumtion-1: The gain constant h must be chosen so that the tem (h-a) is stictly negative and hence h<0. Then main sliding suface can be deived as given in (18) (18) Basing on the developed switching suface, the sliding mode switching contol is defined fom a speed contolle given by Whee β is the switching gain and ) function given as, Assumption-: The gain β must be taken so that (19) sgn( is the sign Conside the Lyapunov function candidate as given in (1). Its time deivative is calculated as: by substituting (17) in () By using (18) in (3) (1) () (3) 4

4 An SMC based RZVDPWM Algoithm of Vecto Contolled Induction Moto Dive fo Bette Speed Response with Reduced Acoustical Noise Using second assumption in (1), then (4) (5) By making use of the Lyapunov s diect method, as the V ( t) is clealy a value of + ve sign, V ɺ ( t) is - ve value and V ( t) eaches to as S ( t) eaches to, and then the stability at the oigin S ( t) = 0 is globally asymptotically stable. Theefoe as t tends to infinity then S ( t) tends to zeo. Moeove, all tajectoies stating fom the sliding suface S=0 should each the suface in finite time and then will emain on this suface. Sliding mode is the tem used to epesent the system s behavio on the sliding suface. When the sliding mode occus on the sliding suface, then, S ( t) = Sɺ ( t) = 0 and then thee is a convegence of the tacking eo e(t) to zeo exponentially. Finally, the efeence toque command T can be obtained by substituting (18) in e (1) as given in (6) 1 T (t) = b [(h.e) βsgn( S) + aω + ɺ ω d] e (6) m m + Theefoe, the sliding mode speed contol esolves the poblem of speed tacking fo vecto contolled induction moto dive, with some uncetainties o distubances in the load toque. IV. PROPOSED SMC BASED RZVDPWM ALGORITHM OF VECTOR CONTROLLED INDUCTION MOTOR DRIVE i ds ω Field weakening contol SMC based Speed contolle i qs i ds PI PI V ds V qs -phase to 3-phase V a V b V c R Z V D P W M Sa Sb Sc V dc 3-Phase Invete Angle and Slip Calculation i qs i ds i qs 3-phase to -phase I a ib ω IM Fig. 3 Block diagam of SMC based RZVDPWM vecto contolled induction moto In VCIMD, Induction moto is diven by using VSI such that slip fequency can be changed accoding to a specific equiement. The slip speed is deived in the feed-fowad manne by assuming the oto speed is measued. Fom the decoupling contol, the oto flux is aligned onto the d-axis of synchonously otating efeence fame, then λ = 0 and λ = λ = L i. Then, the slip can be q given as in (7). d m ds L mr ω sl = i qs (7) L λ the Vecto contol scheme is to egulate λ and oto speed to desied values. Flux linkages and oto speed ae not diectly linked to the stato voltages which geneates the both the vaiables. Hee SMC Speed contolle is used fo contolling the speed. The input to the speed contolle is angula efeence speed and actual speed. The actual q- and d-axis stato cuents ae egulated to the two efeence cuents to get the stato voltages. The invese two phase to thee phase tansfomation is done and the thee phase voltages ae given to the RZVDPWM block, and thus the gating pulses ae geneated to VSI. The Block diagam of SMC based RZVDPWM vecto contolled induction moto is as shown in Fig. 3. So that the positions of oto flux linkages ae obtained by integation of addition of the oto and actual speed. The main objectives in V. SIMULATION RESULTS AND DISCUSSIONS To show the discussed andom PWM appoach, the numeical simulation studies ae done using MATLAB. Fo the simulation esults, 5KHz is taken as the switching Fequency (f s ) of the invete. The induction moto used in 5

ISSN: 49 8958, Volume-6, Issue-1, Octobe 016 this case study is a 4 kw, 400V, 1470 pm, 4-pole, 50 Hz, 3-phase induction moto having the following paametes: R s

4 to Fig. 9. Fig. 4 Pefomance of steady state Line cuent of SMC based SVPWM and RZVDPWM algoithms of vecto contolled dive Fig.

5 ISSN: , Volume-6, Issue-1, Octobe 016 this case study is a 4 kw, 400V, 1470 pm, 4-pole, 50 Hz, 3-phase induction moto having the following paametes: R s = 1.57Ω, R = 1.1Ω, L s = 0.17H, L = 0.17H, L m = H and J = Kg.m. The simulation esults of SMC based SVPWM and RZVDPWM algoithms of vecto contolled dive ae as shown fom Fig. 4 to Fig. 9. Fig. 4 Pefomance of steady state Line cuent of SMC based SVPWM and RZVDPWM algoithms of vecto contolled dive Fig. 5 Stating tansients of smc based SVPWM and RZVDPWM algoithms of vecto contolled dive Fig. 6 Steady state plots of SVPWM and RZVDPWM algoithms of vecto contolled dive 6

6 An SMC based RZVDPWM Algoithm of Vecto Contolled Induction Moto Dive fo Bette Speed Response with Reduced Acoustical Noise Fig. 7 Pefomance duing step change in load toque (a load toque of 0 N-m is applied at 0.5 s and emoved at 0.7 s) of SMC based SVPWM and RZVDPWM algoithms of vecto contolled dive Fig. 8 Pefomance duing speed evesal opeation (Speed is changed fom (+1000 pm to pm) of SMC based SVPWM and RZVDPWM algoithms of vecto contolled dive Fig. 9 Hamonic specta of steady state line cuent in SMC based SVPWM and RZVDPWM algoithms of vecto contolled dive By seeing the esults it can be concluded that the poposed algoithm gives good pefomance duing the tansient and steady state conditions. The poposed algoithm has been developed by using Simplified PWM sequence along with SMC contolle in ode to impove the pefomance of the speed duing step change in load. The hamonic specta of steady state line cuent of RZVDPWM technique gives spead specta which is necessay to educe the acoustical noise when compaed to the SVPWM technique. VI. CONCLUSION In this pape, an sliding mode contolle (SMC) based Random Zeo vecto Distibution PWM (RZVDPWM) algoithm of vecto contolled induction moto dive fo bette speed esponse with educed Acoustical Noise is analyzed. As the poposed appoach eliminates the angle calculation, it is chaacteized by low computational ovehead and easy fo implementation. Fom the simulation esults, it can be obseved that the poposed algoithm gives supeio 7

ISSN: 49 8958, Volume-6, Issue-1, Octobe 016 wavefom quality when compaed with the SVPWM algoithm.

Moeove pefomance of the speed duing step vaiation in the load (a load toque of 0 N-m is applied at 0.5 s and emoved at 0.7 s) is maintained at the same level (1000 pm) without any deviation.

College, Suampalem, Peddapuam, A.P. His eseach aeas include Powe Electonic Dives, PWM, Multi level invetes and FO

7 ISSN: , Volume-6, Issue-1, Octobe 016 wavefom quality when compaed with the SVPWM algoithm. Moeove, as the poposed algoithm gives distibuted hamonic specta, it educes the acoustical noise of the induction moto. Moeove pefomance of the speed duing step vaiation in the load (a load toque of 0 N-m is applied at 0.5 s and emoved at 0.7 s) is maintained at the same level (1000 pm) without any deviation. Hence the poposed concept educes hamonic distotion and acoustical noise effectively when compaed with SVPWM technique. Technical Education and membe in Institute of Electical and Electonics Enginees. M. M.N.V.V. Bahmam gaduated and Post gaduated fom JNTU college of Engineeing, KAKINADA, He is pesently woking as Assistant Pofesso at the Depatment of Electical and Electonics Engineeing, Pagati Engineeing College, Suampalem, Peddapuam, A.P. His eseach aeas include Powe Electonic Dives, PWM, Multi level invetes and FOC techniques. REFERENCES 1. F. Blaschke The pinciple of field oientation as applied to the new tansvecto closed loop contol system fo otating-field machines," Siemens Review, 197, pp Heinz Willi Vande Boeck, Hnas-Chistoph Skudelny and Geog Vikto Stanke, Analysis and ealization of a pulse width modulato based on voltage space vectos IEEE Tans. Ind. Applicat., vol. 4, no. 1, Jan/Feb 1988, pp Michael M.Bech, Fede Blaabjeg, and John K. Pedesen, Random modulation techniques with fixed switching fequency fo thee-phase powe convetes IEEE Tans. Powe Electon., vol.15, no.4, pp , Jul, S-H Na, Y-G Jung, Y-C. Lim, and S-H. Yang, Reduction of audible switching noise in induction moto dives using andom position space vecto PWM IEE. Poc. Elect. Powe Appl., vol.149, no.3, pp , May, Andzej M. tzynadlowski, Konstantin, Yuin Li, and Ling Qin, A novel andom PWM technique with low computational ovehead and constant sampling fequency fo high-volume, low-cost applications IEEE Tans. Powe Electon., vol. 0, no.1, pp.116-1, Jan, Dae-Woong Chung, Joohn-Sheok Kim and Seung-Ki Sul, Unified voltage modulation technique fo eal-time thee-phase powe convesion IEEE Tans. Ind. Applicat., vol. 34, no., Ma/Ap 1998, pp T. Bahmananda Reddy, J. Amanath and D. Subbaayudu, Impovement of DTC pefomance by using hybid space vecto Pulse width modulation algoithm Intenational Review of Electical Engineeing, Vol.4, no., pp , Jul-Aug, K. Satyanaayana1, J. Amanath, and A. Kailasa Rao1, Hybid PWM Algoithm with Low Computational Ovehead fo Induction Moto Dives fo Reduced Cuent Ripple ICGST-ACSE jounal, vol.10, isuue.1, pp. 9-37, Dec, N Subba ao, K. Satyanaayana, K.Siva Pasad Pefomance Impovement of Sliding Mode Contolle based Indiect Vecto Contolled Induction Moto Dives Intenational Jounal of Engineeing and Advanced Reseach Technology (IJEART) ISSN: , Volume-, Issue-1, Januay 016. M. M. Veea Chanda Kuma, gaduated fom JNTU college of Engineeing, KAKINADA, He is pesently Pusuing M.Tech in the Depatment of Electical and Electonics Engineeing, Pagati Engineeing college, Suampalem, Peddapuam. His eseach aeas include Powe Electonic Dives, PWM, Multi level invetes and FOC techniques. D. K. Satyanaayana, obtained M.Tech degee in Powe Electonics fom JNTU College of Engineeing, Hydeabad and Ph.D fom J.N.T.U. College of Engineeing, Kakinada. He is pesently woking as Pofesso and H.O.D. of the Depatment of Electical and Electonics Engineeing, Pagati Engineeing College, Suampalem, Peddapuam, A.P., INDIA. He pesented 3 eseach papes in vaious national and intenational jounals and confeences. His eseach inteests include Powe Electonic Dives, PWM and Vecto Contol techniques. He is a membe in editoial boad of fou jounals. He is a membe and chated Enginee in Institution of Enginees (India), life membe in Indian Society fo 8

ISSN: [Reddy & Rao* et al., 5(12): December, 2016] Impact Factor: 4.116

ISSN: [Reddy & Rao* et al., 5(12): December, 2016] Impact Factor: 4.116 IJESRT INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY SIMULATION COMPARISONS OF INDUCTION MOTOR DRIVE WITH ESTIMATOR AND PLL V. Nasi Reddy *, S. Kishnajuna Rao*, S.Nagenda Kuma * Assistant