International Journal of Information and Technology (IJIT) – Volume 2 Issue 3, May-Jun 2016 ISSN: 2454-5414 www.ijitjournal.org Page 41 A Fifteen Level Cascaded H-Bridge Multilevel Inverter with Space Vector PWM Technique with Reduced Number of Switches R.Anand [1] , M.Kamatchi [2] Assistant Professor [1] , ME Student [2] Mahendra College Of Engineering, Salem Tamilnadu - India ABSTRACT In future multilevel inverter (MLI) technologies becomes exceptionally main choice in the area of very high power medium voltage energy control. Even though multilevel inverter has a number of positives it has negatives in the layer of higher levels by means of large number of semiconductor switches. This may leads to increase in size and cost of the inverter is very high and also raise in losses. So in order to reduce these situations in the new multilevel inverter is proposed to reducing the switches. This paper shows the 15-level cascaded multilevel inverter. The planned 15-level cascaded multilevel inverter is for dropping the total harmonic distortion which is shown in MATLAB/SIMULINK . The switching pattern of semiconductor switches is used to get better the performance of multilevel inverter. This scheme decrease the switching loss and also increase the efficiency. To authorize the developed technique simulations are carried out through MATLAB/SIMULINK. Keywords:- Cascaded Multilevel Inverter, Harmonic Distortion, MATLAB, semiconductor switches, THD,SVPWM I. INTRODUCTION Multilevel inverters are becoming recent trends, because of its modularity and simplicity of control to generate particular number of levels. Multilevel inverters have a number of applications such as ups, in power grid, as solar inverter, induction heating and number of other applications. By increasing the number of dc voltage sources, a sinusoidal like waveform can be generated. Thus the total harmonic distortions decreases which has a great significance in power grid applications. A sine wave output is desirable because many electrical products are engineered to work best with a sine wave ac power source. The standard electric utility power attempts to provide a power source that is a good approximation of a sine wave.. Switch mode power supply (SMPS) devices, such as personal computers function on quality of sine wave power. Ac motors directly operated on non-sinusoidal power may produce extra heat, may have different speed-torque characteristics, or may produce more audible noise than when running on sinusoidal power thus the multilevel inverters with reduced number of switches becomes more significant. The multilevel inverters is classified as, neutral point clamped inverters, flying capacitor multilevel inverters and cascade multilevel inverters. Of this three category cascaded multilevel inverter is recent trend because of its reliability. Table1 shows the comparison of conventional multilevel inverters switching components. Cascaded multi-level inverter uses reduced number of power switches and it produces a sinusoidal like waveform. Cascaded multilevel inverter is series connection of power switches and dc voltage sources. Cascaded multilevel inverters have several advantages when compared to other topologies. The main advantages of using the cascaded multilevel inverters are the high power quality waveforms due to the reduction in the total harmonic distortion and also the reduction of dv/dt stresses on the load, cascaded multilevel inverters can be classified as symmetric and asymmetric multilevel inverters. The main difference between symmetric and asymmetric configuration is the magnitude of dc sources. In symmetric configuration magnitudes of dc sources are same, whereas in the asymmetric configuration magnitudes of the dc sources are different. By using the cascaded multilevel inverters desired number of output voltage levels can be obtained by series connection of a number of dc voltage sources. A number of different topologies have been presented in the literature. Numerous basic units are also presented in the literature. The disadvantage of the symmetric configuration is that it requires more number of power switches when compared to the asymmetric configurations. But the dc voltage magnitude is very high in these papers. Single phase and three phase multilevel inverters can be produced by the series connection of a large number of the basic units. II. CONVENTIONAL SYSTEMS The cascaded multilevel inverter to generate output of 5 levels using 8 switches, 7 Levels with 12 switches, 9 levels with 16 switches, and so on. Using 4 switch and one dc source for each h-bridge and produces the one level of voltage output which is shown in figure 1. Common expression for output voltage Levels,  = ( + 2)/2 where  is the number of switches in the inverter. Each Bridge is outputting 3 Levels, +Vdc, 0, −Vdc. RESEARCH ARTICLE OPEN ACCESS