Performance Improvement of Grid Integrated Voltage Source Inverter Using Different Hysteresis Current Controllers

The gird integration process for the renewable sources is very difficult due to their intermittent nature. One of the potential solutions is, integration of renewables through pulse width modulated voltage source inverters. Commonly current controlled voltage source inverter is widely used for this purpose. Different current control techniques are adopted to control the output of the invert. As compared to other technique hysteresis current control technique has numerous advantages like better dynamic repose, ease implementation with high accuracy. But the hysteresis controller has also some limitation like variable frequency of switching, higher harmonics content in the output, Chances of shorting of the input source. In this paper double band and offset band concept has been implemented by modifying the existing hysteresis band and a comparative evaluation between different techniques is made with respect to harmonic content in the output and switching frequency in MATLAB-Simulink environment.