MPPT Technique

International Journal of Research and Scientific Innovation (IJRSI) | Volume IV, Issue XII, December 2017 | ISSN 2321–2705  

PV fed Seven Level CHB and NPC Converters using MPPT Technique for Low Power Applications: A Comparative Analysis

Satish Kumar Tripathi[1] and Ritesh Diwan[2]

[1, 2]Department of Electronics & Telecommunication Engineering, RIT, Raipur, C.G., India

Abstract – With the advent of efficient DC to DC and DC to AC converters, the performance of standalone and grid connected photovoltaic systems has been improved upto a great extent. Due to the considerably gaining popularity of photovoltaic systems among other renewable resources, power electronic device interface have become an essential key element. This paper describes the comprehensive analysis of seven level cascaded Hbridge (CHB) and neutral point clamped (NPC) multilevel inverters with boost converter using maximum power point tracking algorithm. Maximum power point tracking technique in the photovoltaic systems is implemented using perturb and observe (P&O) to obtain optimal output of PV array by continuously tracking along the maximum power point (MPP). The simulation study has been carried out under MATLAB/Simulation environment.

Index terms –multilevel inverters, cascaded H-bridge, neutral point clamped, maximum power point tracking, photovoltaic cell.

I. INTRODUCTION

The photons carrying the energy of sunlight incident on photovoltaic array is converted into electrical energy. The output power of PV array is capable enough to feed the light loads such as lighting systems and DC motors. However, sensitive and sophisticated applications demand for power electronic converters to process the power output of array. The converters regulate the voltage and current at the load terminal and hence operate the array at maximum power in the grid connected systems [2-3]. The converters equipped with maximum power point tracking (MPPT) technique is based on an algorithm which keeps on detecting the maximum instantaneous power of the PV array. Since the operating point of the array vary intermittently, so the MPPT algorithm is required to set the operating point so as to extract and deliver maximum instantaneous power to the ac load through multilevel inverters [8]. The key advantage lying with the multilevel inverter is the ease of interface with any of the renewable sources such as photovoltaic, wind and fuel cells at the dc input. Multilevel inverters employ a series of power semiconductor devices and capacitors with a single dc source or a multiple dc sources without a capacitor, which generate voltages with stepped waveforms in the output.

Read More