In this study, a multilevel inverter was designed and implemented to operate a stand-alone solar photovoltaic system. The proposed system uses pulse-width modulation (PWM) in the multilevel inverter to convert DC voltage from battery storage to supply AC loads. In the PWM method, the effectiveness of eliminating low-order harmonics in the inverter output voltage is studied and compared to that of the sinusoidal PWM method. This work also uses adaptive neuro fuzzy inference (ANFIS) to predict the optimum modulation index and switch angles required for a five level cascaded H-bridge inverter with improved inverter output voltage. The data set for the ANFIS-based analysis was obtained with the Newton-Raphson (NR) method. The proposed predictive method is more convincing than other techniques in providing all possible solutions with any random initial guess and for any number of levels of a multilevel inverter. The simulation results prove that the lower-order harmonics are eliminated using the optimum modulation index and switching angles. An experimental system was implemented to demonstrate the effectiveness of the proposed system.

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This paper presents nonisolated DC–DC converter which suits for solar photovoltaic (PV) applications. The DC–DC converter proposed in this paper utilizes coupled inductor, voltage boost capacitor and passive clamp circuit to achieve desired voltage gain and the passive clamp circuit will help the converter to accomplish high efficiency. To minimize the voltage spike/ringing across MOSFET drain-source and to recover the coupled inductor leakage energy, the RCD clamp circuit is used. The voltage lift capacitor along with the clamp circuit helps in increasing the voltage gain of the converter. The proposed converter offers low voltage stress on MOSFET and diode, low-coupled inductor turns ratio with low duty cycle. The converter is analyzed and simulated with PLECS standalone simulating environment for all aspects of the clamp circuit. The simulation results are compared with RCD and other clamping circuits to verify the performance of the proposed converter. The converter is also compared with active clamping to discuss the effectiveness of passive clamping circuit. To track the maximum power from the solar PV module, the conventional maximum power point tracking (MPPT) techniques are used. The prototype is designed and implemented for 150W and experimental results are verified.

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