Harmonic elimination in a PV fed multilevel inverter integrated with a micro grid
Tilak Thakur, Shimi S L and Jagadish Kumar
PEC University of Technology, India
National Institute of Technical Teachers Training & Research, India
: J Electr Eng Electron Technol
Abstract
Power quality issues and energy crises are the major apprehension of this century. Most of the literature in this area of research discusses the problems related to natural resource depletion, environmental impact, the rising demand of new energy resources and the challenging technologies which can overcome these problems. The renewable sources of energy such as solar, wind, biomass, hydro, geothermal and so forth are zero polluting in nature and have large research scope. The output of such energy resources are mostly in the form of DC which needs to be converted into AC for feeding the AC loads. This requires DC to AC converters. Multilevel converters are gaining high reputation because even in high power applications, the renewable energy sources such as photovoltaic arrays, fuel cells and wind turbines etc., can be used as DC input to the multilevel inverter with higher efficiency. Thus, this paper focus on the harmonic elimination of a grid tied multilevel inverter fed with PV arrays. The nonlinear characteristic of PV array and the power electronics switches in the inverter introduces harmonics in the power system. According to IEEE 519 standard, for a 69KV and below system, the Total Harmonic Distortion (THD) value should be less than 5% and the individual harmonics should be less than 3%. Filtering increases the complexity and cost of the system. Therefore, the best alternative is to use suitable low frequency switching scheme for the multilevel inverter to mitigate harmonics. Thus, the investigators propose to use Newton-Raphson based Selective Harmonic Elimination (SHE) technique to eliminate the harmonics and compare it with the conventional PWM technique. The entire system will be simulated using MATLAB™/SIMULINK™.