Performance of Isolated Generating System with Multilevel Inverter using Photovoltaic Source Ajay Kumar Maurya M.Tech. (Power System), Student Gautam Buddha University, Gr. Noida, India ajaymauryaee@gmail.com Yogesh K Chauhan, Member IEEE Gautam Buddha University Gr. Noida, India Abstract— Solar PV is one of the demanding nonconventional sources for generation of electricity but it has its own limitation due to non-linear characteristics. Solar PV needs MPP tracker to extract maximum power form solar PV source. Furthermore, multilevel voltage source inverter (VSI) is used for converting dc voltage into closed to sinusoidal ac supply. In this paper, incremental conductance (IC) technique for tracking maximum solar power is proposed with five-level VSI for converting solar PV dc voltage into three phase ac output voltage. Moreover, a unipolar PWM technique is proposed for VSI to producing gating pulses for Insulated gate bipolar transistor (IGBT) used in the VSI. Multilevel inverter is used to reduce filtering requirements and to reduce amplitude of all harmonics in inverter output. The complete model is simulated in MATLAB/SIMULINK and extensive simulations are carried out to validate the proposed system. Keywords— Five level PWM inverter; Incremental conductance technique; MPP tracking; Photovoltaic array model; standalone generating system; Unipolar PWM Converter. I. INTRODUCTION Nowadays solar photovoltaic (PV) is gaining popularity among researchers due to various advantages associated with it. Generation of pollution free electricity is one of the main advantages of solar PV. It is evident from the literature that solar PV system is well suited for remote or arid regions [1]. PV cells characteristics is highly non-linear in nature. The PV cells characteristics depend upon environmental condition i.e. temperature and solar insolation (intensity of light). The PV cell produces maximum power at knee reason of its I-V or P-I characteristic. This knee reason is known as operating point of solar PV and referred as maximum power point (MPP) of solar PV [2]. The MPP depends upon the variation in environmental conditions and got changed. It needs to be extracted maximum available power for the efficient utilization of solar PV array. For this purpose it needs to be implemented maximum power point tracking device to forcefully operation of the solar PV at maximum power point. Various MPP tracking strategies are found in literature [3]. Few of these tracking techniques are Perturb-and-observe (P & O) technique [4], Incremental Conductance (IC) technique [5], artificial intelligence based technique etc. [6][7][8]. Most of these techniques are complicated and hard to implementation. The techniques such as IC and P&O are widely used to track MPP of solar PV system due to advantages of simplicity and easy to implement. In this paper IC technique is proposed for tracking maximum power. Solar PV generates dc power however most of the electrical appliances are operated on ac power. For the supply purpose dc power needs to be converted into ac power. Multilevel converters are best choice for conversion of dc power into ac power. Multilevel converter produces staircase waveform or voltage level increases in step so it produced lower dv/dt stress in load side with low harmonic distortion [9]-[10], thus reducing filter requirements. In this paper research scope has been identified and endeavor has been made to integrate the solar PV system operated at MPP and five-level VSI. The modeling and simulation studies have been carried out on the proposed integrated PV system. II. SYSTEM DESCRIPTION The whole system model is separated into three major portions A. Solar PV array model, B. MPP tracking module C. Three phase five level voltage source inverter (VSI) topology and associated control circuitry to generate necessary gating pulses. Fig.1. Schematic diagram of complete system The complete scheme, block representation of the proposed system is shown in fig.1. The MPP tracking module is interfaced with PV source to forcefully extraction of the maximum power from solar PV array. Solar power at MPP is fed to three phase five level VSI, which indeed generates three- 978-1-4673-5149-2/13/$31.00 ©2013 IEEE International Conference on Microelectronics, Communication and Renewable Energy (ICMiCR-2013)