An Investigation on Interconnection of Micro Wind Turbines using Multilevel Converters

Abstract

The increase in demand for electricity coupled with the obligation to use sustainable technologies has extended research and development to small and micro wind turbine based electricity generation systems. When it comes to micro wind energy systems, one of the important criteria in commissioning/operating is overall simplicity of the system apart from the system’s capability to produce power adhering to established standards. To meet these requirements, a novel switching network, referred in this research work as comparator based switching signal selection (CSSS) network, has been proposed for controlling the series connected inverters of the micro wind energy system. The CSSS network eliminates the complexity in switching signal generation process like generation of multiple carrier waveforms or performing complex calculations. The network also enables the use of any two level inverter modulation schemes to control any levels of series connected inverter. To demonstrate the effectiveness of employing this switching network in a micro wind energy system, a comprehensive analysis has been performed using performance parameters like output rms value, harmonic distortion of output voltage and current, and k-factor of the transformer. A comparative analysis of the parameters under wide operating conditions has also been performed to understand how comparable the performance of the CSSS network is, to the existing modulation schemes. The results indicate that by employing the CSSS network, satisfactory performance can be obtained from the system for wide operating conditions. The structure of the network can also simplify the implementation of control algorithm.