Application of Tuned Passive Filter for Industrial Six-Pulse Rectifier with R-L Load Viralkumar A. Rana 1 Keyur Rana 2 Atul Talati 3

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1 IJSRD - International Journal for Scientific Research & Development Vol. 2, Issue 02, 2014 ISSN (online): Application of Tuned Passive Filter for Industrial Six-Pulse Rectifier with R-L Load Viralkumar A. Rana 1 Keyur Rana 2 Atul Talati 3 1, 2, 3 Student 1, 2, 3 B. V. M. Engineering College, V. V. Nagar, Gujarat, India Abstract---Power electronic devices find tremendous applications in industry as well as in domestic appliances. The excessive use of these devices causes major problems to the power system due to generation of current harmonics. These harmonic current pollute the power system and produce many adverse effect like malfunction of sensitive equipment, reduced power factor, overloading of capacitor, flickering lights, over heated equipments, reduced system capacity etc. This paper proposes the sources of the harmonics in the power system by converter, rotating machine, transformer, arc furnace and especially for the sixpulse rectifier with industrial R-L load and provide the harmonics mitigation technique to remove the harmonics contains from the power system to make it harmonic free. Keywords: Harmonics, six-pulse, rectifier, voltage, current. I. INTRODUCTION With the increasing in the demand of the electricity day by day, because of the increasing in the industrial sector, it is necessary to increases the generation. Also, because of this industrial growth, so many difficulties are arises in the electrical power system. Difficulties, in the sense, the voltage and the current limits are violated. Also, the frequency waveforms are fluctuated because of the use of power electronic device. There are so many issues which are arising because of the poor power quality. Modern consumers of power such as Switch Mode Power Supply (SMPS), variable speed drives etc. Significantly contribute to the energy saving. Also, the power electronic devices like power diodes, SCR, IGBT are most commonly used. The power handling capacity of this power electronic device is very large. However, their use in the industry as well as in home appliances will cause a nonsinusoidal flow of current from the supply. This current consists of fundamental wave and its integer multiples called as Harmonics. The main generation of this harmonics are the because of the use of electrical arc furnace, power electronic devices etc. Because of use of these devices, the quality of power reduces. Also, it will cause the problem like overheating, reducing equipment life, reducing overall system efficiency. It will also cause overloading of capacitor bank, de rating of equipment and also includes the mal operation of electronic control. So, to nullify this passive filters are used. because of this, depends upon the number of pulses in the converters. The harmonics order can be Pn+1 and Pn-1, if P is the number of pulses of converter and n is the integer. B. Harmonics generated by Rotating Machine Harmonics are generated in rotating machines if magnetic flux distribution is not sinusoidal around the air gap. However, in practical design, the flux distributed is not purely sinusoidal. If the design includes imperfection then space harmonics can be generated. Also because of the magnetic saturation, harmonics can be generated. C. Harmonics generated by Transformer In the design of transformer, it includes the optimum use of magnetic core materials, resulting in the peak magnetic flux density. Due to this, there is a considerable amount of saturation. Also, the magnetizing current associated with transformer core saturation includes odd order harmonics. Triplen order harmonics are absorbed by the delta winding of star-delta connection of transformer. For the balanced operation, harmonics generated by transformer are of the order of 6n+1 and 6n-1. D. Harmonics generated by arc furnace Because of the highly non-linear voltage, current characteristic, arc furnaces produces harmonics in the power system. There is a wide variation in frequency because of sudden application of arc furnaces. III. SIMULATION RESULT The Matlab simulation is developed for 6-pulse diode bridge rectifier. Fig.1 shows the simulation circuit diagram of the 6-pulse diode bridge rectifier for industrial R-L load without harmonics filter. II. SOURCES OF GENERATION OF HARMONICS A. Harmonics generated by converter Because of the use of the power electronic device in converters, harmonics are generated. Because of the switching of these devices, the waveform of voltage and currents are distorted. The order of harmonics generated Fig. 1: 6-pulse diode bridge rectifier with R-L load and without harmonics filter. All rights reserved by 652

2 As we show in fig.1 the harmonics filters are not connected to the system and after the three phase current and voltage waveform is measured in the scope. The wave form of three phase current and voltage is shown in the fig.2. Application of Tuned Passive Filter for Industrial Six-Pulse Rectifier with R-L Load Fig. 2: Three phase current and voltage waveform. The wave form of the three phase current and voltage in the Fig.2 is not the sinusoidal because they contain the harmonics due to the electronics device diode. The goal of this paper is to reduce the THD level from the system. Here we have used the 6-pulse rectifier which is generate the harmonics as 6K where k is the integer and the value of K=1,2,3, so, the six pulse rectifier bridge generate the 5,7,11,13, harmonics. The Fig.3-8 Shows the THD level in the voltage and current wave forms. Fig. 4: THD level in the Phase b voltage waveform. Fig. 3: THD level in the Phase a voltage wave form. Fig. 5: THD level in phase b Voltage Waveform In the Fig.3, 4 and 5 the THD level in the phase a, b and c voltage waveform contains 16.84%, 18.65% and 18.22% respectively. All rights reserved by 653

3 Application of Tuned Passive Filter for Industrial Six-Pulse Rectifier with R-L Load Fig. 6: THD level in phase a Current waveform In the Fig.6-8 the THD level in the phase a, b and c current waveform contains 16.96%, 16.97% and 17.14% respectively. Fig. 8: THD level in phase c Current waveform. From the above figures the THD level in the current and voltage waveform are not acceptable for that the harmonics level in the waveform in reduce by connecting the shunt passive filter in the system which shown in Fig.9. Fig. 7: THD level in phase b Current waveform. Fig. 9: Six-pulse diode bridge rectifier with R-L load and with harmonics filter. Fig.9 show the simulation circuit diagram of 6- pulse diode bridge rectifier with R-L load and with harmonics filter. As explain earlier that 6-pulse rectifier generate 5, 7, 11, 13 harmonics for that here 5 th, 7 th, 11 th, All rights reserved by 654

4 13 th and high pass filters are connected for reducing the harmonica level. Application of Tuned Passive Filter for Industrial Six-Pulse Rectifier with R-L Load Fig. 10: Three phase voltage and current wave form after connecting the filter From the Fig.10 shows the three phase voltage and current after connecting the filters to the system. After connecting the filter to the system the shape of the waveform becomes approximate sinusoidal as shown in Fig.10. Fig. 12: THD level in the Phase b voltage wave form Fig. 11: THD level in the Phase a voltage wave form. Fig. 13: THD level in the Phase c voltage wave form. In the Fig the THD level in the phase a, b and c voltage waveform are reduce from 16.84%, 18.65% and 18.22% to 8.24%, 7.82% and 7.95% respectively. All rights reserved by 655

5 Application of Tuned Passive Filter for Industrial Six-Pulse Rectifier with R-L Load Fig. 14: THD level in the Phase a current wave form. Fig. 16: THD level in the Phase c current wave form. In the Fig.6-8 the THD level in the phase a, b and c current waveform reduce from 16.96%, 16.97% and 17.14% to 5.61%, 5.50% and 5.56% respectively. IV. CONCLUSIONS This paper propose the different sources of harmonics, and also provide the simulation results for the six-pulse rectifier R-L load with and without harmonics filter. From the result we can conclude that without harmonics filter the voltage and current wave form are distorted due to the presence of the harmonics, after connecting the harmonics filter the waveform becomes the approximate sinusoidal also the THD level of waveforms are reduce to permissible limit. ACKNOWLEDGMENT My appreciation for the presenting this paper goes first to my family for that absolute support. I am thankful to our HOD Dr B.R.Parekh for imparting fundamental idea, which helped me a lot for my mini project.i also want to thank my friends and entire staff of Electrical Department for providing a solid background for my studies. Fig. 15: THD level in the Phase b current wave form. REFERENCES [1] D. A. Gonzalez, John C. Mccall, IEEE transaction. Industry Application, Design of filter to reduce harmonic distortion in industrial power system, Vol. IA-23, No:3 PP, , May [2] J. W. George, Power systems harmonics fundamentals analysis and filter design, Springer 2001 [3] Z. A. Menon, M. A. Uquaili, M. A. Unar, Harmonics mitigation of industrial power system using passive filters, Mehran University Research Journal of All rights reserved by 656

6 Engineering & Technology, Volume 31, No. 2, April, 2012 [ISSN ] [4] S. A. Ali, W. F. A. Shehab, Harmonics elimination in industrial networks using filters, European Journal of Scientific Research, Vol.56, pp , [5] M. S. Khan, I. Intesar, M. S. Raheel, M. B. Ali, U. Asad, M. Farid, U. Ahmed, P. A. Ayub, Implementation of a passive tune filter to reduce harmonics in sin-gle phase induction motor with varying load, International Journal of Engi-neering & Technology, Vol: 11 No: 03, IJET-IJENS, June 2011 [6] D. J. Perrault, J. G. Kassakiain, Effect of firing angle imbalance on 12 pulse rectifiers with interphase transformers, IEEE Transactions On Power Electronics, Vol.10, no.3, may [7] Gelman, Improving power quality through harmonics cancellation in multiphase rectifiers, Controls, World Academy of Science, Engineering And Technology, Application of Tuned Passive Filter for Industrial Six-Pulse Rectifier with R-L Load All rights reserved by 657