Ahmad Shukri Fazil Rahman* et al. / (IJITR) INTERNATIONAL JOURNAL OF INNOVATIVE TECHNOLOGY AND RESEARCH Volume No. 1, Issue No. 3, April - May 2013, 226 – 232. ISSN 2320 –5547 @ 2013 http://www.ijitr.com All rights Reserved. Page | 226 Microcontroller Based SPWM Generator: A Conventional Design Perspective Through Graphical Oriented Approach AHMAD SHUKRI FAZIL RAHMAN 1 MUZAIDI OTHMAN@MARZUKI 2 ABDUL RAHIM ABDUL RAZAK 3 SYAFRUDDIN HASAN 4 BAHARUDDIN ISMAIL 5 SYED IDRIS SYED HASSAN 6 Pusat Pengajian Kejuruteraan Sistem Elektrik,d/a Kompleks Pusat Pengajian Kejuruteraan Mikroelektronik Universiti Malaysia Perlis (UniMAP),Kampus UniMAP Pauh Putra , 02600 Arau, Perlis, Malaysia. Abstract- In this paper, a comprehensive design strategy was proposed and implemented for the design of a single phase sinusoidal pulse width modulation (SPWM) waveform. Excel software was used to generate the timing sequence, and then fed to a microcontroller unit (PIC16F877A). Through Excel, complex programming effort could be avoided and the whole data arrays can be presented graphically. The effectiveness of the timing sequence was validated by using PROTEUS software. The simulation result shows that the SPWM waveform achieved the desired goals. Keywords-SPWM, PWM, sinusoidal, triangular, modulation, carrier, excel, Proteus, inverter. I. INTRODUCTION Commonly used in inverter system, the SPWM or sinusoidal pulse width modulation is a part of control algorithm which rises’ from the many variety of pulse width modulation (PWM) control technologies. Its application has widened that include motor control, induction heating, welding power source, electronic converters [1, 2], wind power generation [3], flexible transmission system (FACTS) controllers [4] and etc. As the name implies, SPWM is a comparison between a reference modulation (sinusoidal) waveform and a carrier (triangular) waveform which resulted in PWM (gate) signals for switching devices. The width of each respective PWM signal is proportional to the amplitude of a sine wave. Fig. 1 shows a typical SPWM generation theory and its resultant PWM signal. Fig. 1. SPWM comparison Signals (top) and PWM signal output (bottom) There are several ways of producing SPWM signal, the method mainly consists of modulation or with the introduction of dedicated microcontroller [1, 3, 5-8]; which is producing greater accuracy than analogue circuits [7]. Other known methods emphasized the use of matlab simulink [7-9] and Labview [10] at design stage to performed SPWM process. With the rapid advancement of SPWM technology [11-15], complex circuitry could be integrated in a single chip thus reducing the complexity and increasing its capability [16]. Even though common method of loading complex programming SPWM algorithm to a single chip may compromise the chip performance [6]. Thus, the entire process could be avoided by performing the required task (SPWM comparison signal) through excel, this may reduce the degree of programming complexity and the chip performance can be fully optimize. It is the intentions of this paper to investigate the graphical approach by using excel 2007 to generate the PWM signal. These signals will be compared (sinusoidal and triangular) and then the output from the comparison will be used to generate the PWM signal. Thus, the required signal will be generated without affecting the performance of the microcontroller. Proteus Isis version 7.7 was used to simulate the PWM signal through PIC16F877A microcontroller. II. SPWM DESIGN PERSPECTIVE Presently, SPWM can be generated through symmetric regular sampling method and asymmetric regular sampling method [5] as per fig 2 [5] and fig 3 [17]. The excel SPWM generation brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by International Journal of Innovative Technology and Research (IJITR)