In this paper a novel 5 switch seven level DC-AC inverter is being proposed. The proposed multilevel inverter uses reduced number of switches as compared to the switches used in the conventional multilevel inverter. The inverter has been designed to generate a 7 level AC output using 5 switches. The voltage stress on each of the switches as well as the switching losses is found to be less, minimized common mode voltage (CMV) level and reduced total harmonic distortion. The proposed 7-level inverter topology has four dc sources, which is energized through the PV system. Proposed inverter is controlled with help of multicarrier sinusoidal pulse width modulation (MCSPWM).The simulation and hardware results were verified using matlab simulink and dspic microcontroller respectively.
- DsPIC controller
- Multicarrier sinusoidal pulse width modulation (MCSPWM)
- Multilevel inverter
- PV system
Figure 1. Novel 7 Level 5switch inverter topology
EXPECTED SIMULATION RESULTS:
Figure 2. 7-level stepped output voltage of proposed system
Figure 3. Output current of proposed system inverter topology
Figure 4. Switching pulses generation using MCSPWM
Figure 5. Voltage across the switches placed in the proposed inverter
Figure 6. THD analysis of proposed system (a) output voltage (b) output current
In this proposed paper, the multicarrier sinusoidal pulse width modulation scheme was implemented to produce a seven level stepped output voltage with reduced harmonics. The proposed inverter energized by using photovoltaic system, which boosted through the boost converter. Also this system which minimises the common mode voltage level, voltage stress across the various switches improves output and better current control is accomplished. And the simulation and experimental results were verified using matlab16 and dspic controller respectively.
 Poh Chiang Loh, Feng Gao, FredeBlaabjerg, and Sokweilim,” Operational Analysis and Modulation Control of Three-Level Z-Source Inverters With Enhanced Output Waveform Quality,”IEEE Transaction On Power Electronics, Vol.24, No.7, July 2009.
 SamirKouro, Pablo Lezana, Mauricio Angulo and José Rodríguez, ”Multicarrier PWM with Dc-Link Ripple Feedforward Compensation For Multilevel Inverters,” IEEE Transactions on Power Electronics, Vol. 23, No.1, January2010.
 S. Mohamed Yousuf, P. Vijayadeepan, Dr. S. Latha, “The Comparative THD Analysis of Neutral Clamped Multilevel Z-source Inverter Using Novel PWM Control Techniques” IJMER Vol.2, Issue.3, May-June 2012 pp-1086-1091.
 Huafeng Xiao, ShaojunXie, Chen Yang, “Transformerless Split-inductor Neutral point clamped Three-level PV Grid-Connected Inverter” IEEE Energy Conversion congress and Exposition (ECCE), 2010 pp. 2929-2936
 Bharatiraja, C., Raghu, S., Rao, P., Paliniamy, K.R.S. “Comparative analysis of different PWM techniques to reduce the common mode voltage in three-level neutral-point- clamped inverters for variable speed induction drives”, International Journal of Power Electronics and Drive Systems, vol. 3, Issue 1, March 2013, Pages 105-116.