MODULATION INDEX AND SWITCHING FREQUENCY EFFECT ON SYMMETRIC REGULAR SAMPLED SPWM

Öz

Inverter, is an electronic device or circuitry that changes direct current (DC) to alternating current (AC). The output voltage and frequency of the inverter can be changed. There are different modulation methods used in inverter control. Some of these methods can be applied digitally, some analogously. Classical Sinusoidal Pulse Width Modulation (SPWM) is a method normally performed analogously. Known methods for digitally applying this method are regular sampled sinusoidal PWM methods. In this study, the implementation of symmetric regular sampled sinusoidal PWM method is discussed. Two fundamental factors that are effective in this kind of modulation methods are investigated by harmonic analysis of switching frequency and modulation index, inverter pole voltage and line voltage. From an inverter that supplies a three-phase RL load, the fundamental component and the generated harmonics are investigated using the Symmetric Regular Sampled SPWM method with five different switching frequencies and three different modulation index values. Modulation index is investigated for linear region and over modulation regions. Low, normal and high switching frequency samples are also chosen for switching frequency. The obtained harmonic analysis results are presented in the study.

Anahtar Kelimeler

• Modulation index,Switching frequency,Inverter,Symmetrical regular sampled SPWM

Kaynakça

1. [1] Sarıoğlu, K., Gökaşan,M., Boğosyan,S., ‘‘Asenkron Motorlar ve Kontrolu’’ Birsen yayınları, 2003
2. [2] Gülgün, R., ‘‘Güç Elektroniği’’ Yıldız Teknik Üniversitesi Yayınları ,İstanbul 1995
3. [3] Kaynak,O., ‘‘Güç Elektroniği: Elemanlar Devreler ve Sistemler’’Ağutos 1988
4. [4] Williams, B.W, ‘‘Power Elektronics’’ 1992
5. [5] Ertan,H.B, Üçtuğ,M.Y, Colyer,C.,Consoli,A. ‘‘Modern Elektrical Drives’’ 1994
6. [6] Skvarenina, T.L., ‘‘Power elektronics handbook’’ CRC press , 2002
7. [7] Xiao-ling W., Xiang-gen Y., ‘‘The Unified PWM İmplementation Metod for Three-Phase İnverter’’ Second IEEE Conference on İndustrial Electronics and Aplication, 2007
8. [8] Narayanan,N., Ranganathan, V:T., ‘‘ Overmodulaton algoritma for space vector modulated inverters and its application to low switching frequency PWM tecniniques’’ IEE proc.-electr. Power appl. 148,6,November 2001

9. [9] Kentli, F., & Yilmaz, M. (2015). Mathematical modelling of two-axis photovoltaic system with improved efficiency. Elektronika ir Elektrotechnika, 21(4), 40-43.
10. [10] Zeng,Q., Chang,L.,Song,P., ‘‘SVPWM-based current controller with grid harmonic compensation for three-phase grid-connected VSI’’ 2004 35th anunual power Electroniks Specialist conferance’’ Aachen,Germany, 2004
11. [11] Chen.,Y., Tong, Y. Jin.,X., ‘‘A Novel Algorithm of SVPWM Harmonik Analysis’’ Second IEEE Conference on İndustrial Electronics and Aplication, 2007
12. [12] Bose,B.K, ‘‘Modern Power Elektronics and AC Drivers’’ Prentice-hall, 2002
13. [13] Rashid,M.H., ‘‘Power Elektronics Handbook’’ Academic press, 2001