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 Pofesso, Dept. of EEE, Malineni Peumallu Educational Scoety s Goup of Institutions, Guntu, Andha Padesh, India Assistant Pofesso, Dept. of EEE, Univesal College of Engineeing & Technology, Guntu, Andha Padesh, India DOI: 10.5281/zenodo.203959 ABSTRACT This pape poposes a new contol scheme fo contolling of Induction Machine. In this contol mechanism we ae compaing the esults with diffeent schemes as 1. Roto angle based speed estimation and 2. Phased lock loop based speed estimation. Then it is peceded with compaison though these two estimation methods. The simulation has been done and esults is veified and validated in MATLAB /SIMULINK with diffeent test conditions. KEYWORDS: Induction Moto, PLL, V/f Contol. INTRODUCTION The adjustable speed dives (ASD) ae used moe and moe in industial pocesses. The widespead industial use of Induction Moto (IM) has been stimulated ove the yeas by thei elative cheapness, low maintenance and high eliability. The contol of IM vaiable speed dives [1] often equies contol of machine cuents, which is nomally achieved by using a voltage souce invete. A lage numbe of contol stategies have been egisteed so fa. The volts pe hetz (v/f) contol of IM dives with invetes ae widely used in a numbe of industial applications pomising not only enegy saving, but also impovement in poductivity and quality. The low cost applications usually adopt v/f scala contol when no paticula pefomance is equied. Vaiablespeed pumps, fans ae the examples. Fo those applications which equie highe dynamic pefomance than v/f contol, the dc moto like contol of IM that is called, the Field Oiented Contol (FOC) is pefeed. Duing the last few yeas, a paticula inteest has been noted on applying speed FOC to high pefomance applications that is based on estimation of oto speed by using the machine paametes, instantaneous stato cuents and voltages.the benefits of speed sensoless contol ae the inceased eliability of oveall system with the emoval of mechanical sensos, theeby educing senso noise and dift effects as well as cost and size. Howeve to exploit the benefits of sensoless contol, the speed estimation methods must achieve obustness against model and paamete uncetainties ove a wide speed ange. To addess this issue, a vaiety of appoaches have been poposed. While all the speed techniques eliminate the use of mechanical speed senso, they equie the stato cuent and stato voltage signals as input. This equies at-least two cuent sensos and two voltage sensos on the stato side. It is difficult to get cuent sensos with equal gains ove the wide ange of fequencies, voltages and cuents used in a pactical invete. The poblem is exacebated if the moto windings ae not pefectly balanced o if the cuent sensos have some dc offset. Ove last few yeas, techniques of stato cuent econstuction fom the dc link cuent have been suggested in liteatue. [523]
The emaining of sections of the pape ae oganized as follows. In Section II, Induction moto modeling. In Section III, contolle design, Simulation esults ae pesented in Section IV. INDUCTION MOTOR MODELLING In this pape a squiel cage Induction moto is modeled based on the Roto efeence fame. Toque developed by the induction machine is given by T e K P K i ef s dt Hee based on the speed eo we contol the induction machine speed CONTROLLER DESIGN 1 Roto angle based contolle The contolle is designed by using the flux estimation. The flux calculation was done fom the cuents though the machine. Hee we ae consideing only the mutual inductance of machine fo the flux linkages The mathematical fomulae fo estimation of machine as follows P hi L m I d * 1 T s Hee L m epesents mutual inductance and I d epesents Diect axes cuents. In this section oto angle is estimated by using the speed and integato. Hee the discete integato is pefeed fo the estimation of angle of the machine m and W m is the oto speed. L m I q * T * P The angle theta is used fo the estimation of the Id and Iq cuents fom the pak tansfomation. Whee I q estimated as follows, 2 PLL Based Contolle hi 2 2 L T I q * * * 3 P Lm P In PLL based contolle is designed by using the phased lock loop. Phased lock loop is used fo the angle estimation fom the cuents of the induction moto. The block diagam of the PLL based contolle is shown in the Fig.1 e hi [524]
Fig 1. Block diagam of the PLL used fo the estimation of angles The thee-phase input signal is conveted to a dqo otating fame (Pak s tansfomation) using the angula speed of an intenal oscillato. The quadatue axis of the signal, popotional to the phase diffeence between the abc signal and the intenal oscillato otating fame, is filteed with a mean (Vaiable Fequency). A Popotional-Integal-Deivative (PID) contolle, with an optional automatic gain contol (AGC), keeps the phase diffeence to 0 by acting on a contolled oscillato. The PID output, coesponding to the angula velocity, is filteed and conveted to the fequency, in hetz, which is used by the mean value. 3 Hysteesis Contolle The hysteesis contolle is used fo the geneation of pulses instead of pulse width modulation. Hee an advantage is geneation of pulses in the band of hysteesis. Hysteesis band will potect the pulse geneation efficiency and effectiveness compaed with the pulse width modulation. This pulses geneated with diffeent bands with the band ange of 0.05 to 10. It gives much esponse with the band value of 0.5 to 5 of effective value. Fig 2. Poposed contolle fo the IM dive system SIMULATION RESULTS The simulation model had been geneated based on the contolle as shown in the Fig.3and the simulation studies have been discussed based on two conditions. [525]
a) Constant efeence speed signal b) Time vaiant efeence speed signal Fig.3 Simulink Implementation of Induction Moto Dive a) Constant efeence speed signal Fig4. Pefomance esults of Induction Machine with constant efeence contol as d-axis flux, q-axis flux, speed, d-axis cuent and q-axis cuent with oto angle estimation. [526]
Fig5. Pefomance esults of Induction Machine with constant efeence contol as d-axis flux, q-axis flux, speed, d-axis cuent and q-axis cuent with PLL. In this case the constant efeence speed signal taken as the efeence and while situation we obseve the chaacteistics of the induction machine esponse in case of oto efeence angle based speed tacking system the speed tacking eo is vey low and contolle will gives much efficient manne. The optimal flux automatically eaches an adequate value consistent with the load toque value, highlighted by the behavio of the tansient due to the load toque decement. Results can be obtained in the case of the PLL obseve based contolle. the oto velocity and the optimal squae oto flux modulus, and thei efeences the powe loss in coppe and coe, and the stato cuent and voltage components b) Time vaiant efeence signals In this section, conside time vaiant efeence signal. This efeence aims at veifying the pecision and the chatteing effect of the poposed contolles. In paticula, it is woth noting the good pefomance of the two contolles even when cossing the zeo, both contolles pefom well when the efeence apidly changes. The contol pefomance with the two obseves is hee evaluated consideing the pecision eo [527]
Fig 6. Pefomance esults of Induction Machine with vaiable efeence contol as d-axis flux, q-axes flux, speed, d-axis cuent and q-axis cuent with oto angle estimation. CONCLUSION In this pape, two contol schemes fo IMs have been designed and simulated. Both schemes use a contolle designed to tack a desied oto velocity signal and an optimal oto flux modulus. The unmeasued vaiables ae econstucted by means of a contolle, which allows the detemination of the oto flux, and by two types of obseves fo the flux estimation: the fist consists of a futhe toque estimation, and the second is based on a genealization of the PLL technique. In geneal, both contol schemes yields satisfactoy esults, as veified by numeic simulations making difficult to decide which contol scheme pefoms bette. Some inteesting issues emain to be investigated, such as the digital implementation of these contolles. REFERENCES 1. Habovcov A, V. Rafajdus, P. Fanko, M. HUD AK, P. : Measuements and Modeling of Electical Machines, EDIS publishe of Univesity of Zilina, 2004. (in Slovak) 2. Fanko, M. Habovcov A, V. HUD AK, P. : Measuement and Simulation of Pemanent Magnet Synchonous Machines, XI. Intenational Symposium on Electic Machiney in Pague, ISEM 2003, 10 12 Septembe 2003. 3. BOSE, B. K. : Powe Electonics and Vaiable Fequency Dives. Technology and Applications, Institute of Electical and Electonics Enginees, Inc, New Yok, 1997. 4. VAS, P. : Sensoless Vecto and Diect Toque Contol, Published in the United States by OxfodUnivesity, 1998. 5. B. K. Bose, Powe Electonics and Moto Dives, Delhi, India, Peason Education, Inc., 2003. 6. M. Rodic and K. Jezenik, Speed-sensoless sliding-mode toque contol of induction moto, IEEE Tans. Ind. Electon., vol. 49, no. 1, pp. 87-95, Feb. 2002. 7. L. Hanefos, M. Jansson, R. Ottesten, and K. Pietilainen, Unified sensoless vecto contol of synchonous and induction motos, IEEE Tans. Ind. Electon., vol. 50, no. 1, pp. 153-160, Feb. 2003. [528]
8. M. Comanescu and L. Xu, An impoved flux obseve based on PLL fequency estimato fo sensoless vecto contol of induction motos, IEEE Tans. Ind. Electon., vol. 53, no. 1, pp. 50-56, Feb. 2006. 9. Radu Bojoi, Paolo Guglielmi and Gian-Maio Pellegino, Sensoless diect field-oiented contol of thee-phase induction moto dives fo low-cost applications, IEEE Tans. Ind. Appl., vol. 44, no. 2, pp. 475-481, Ma. 2008. 10. I. Boldea and S. A. Nasa, Electic Dives, New Yok: Taylo & Fancis, 2006. 11. S. Maiti, C. Chakaboty, Y. Hoi, and Minh. C. Ta, Model efeence adaptive contolle-based oto esistance and speed estimation techniques fo vecto contolled induction moto dive utilizing eactive powe, IEEE. Tans. Ind. Electon. vol. 55, no. 2, pp. 594-601, Feb. 2008. 12. B. Saitha and P. A. Janakiaman, Sinusoidal thee-phase cuent econstuction and contol using a dc-link cuent senso and a cuve-fitting obseve, IEEE Tans. Ind. Electon., vol. 54, no. 5, pp. 2657-2662, Oct. 2007. [529]