Availability Based Load Harmonic Compensation Using PV Inverter

With the proliferation of non-linear loads, the power quality particularly in the distribution level of the grid is deteriorating. The recent grid codes impose limit on the total demand distortion (TDD) and harmonic distortion (HD) level caused by these non-linear loads. The recent published researches focus on how to exploit the embedded photovoltaic (PV) inverters to meet the limit without further investing in custom power devices. In this regard, it is important to ensure that the reference current of the inverter should not exceed its maximum current rating to prevent the saturation of the current controller. The relevant control techniques either suffer from the saturation of the current controller or they fail to meet the TDD and HD levels individually. Therefore, to address these issues, an adaptive load harmonic compensation technique with the PV inverter is proposed in this work. The proposed technique adaptively determines the level of load harmonic compensation, thereby ensures the current controller does not saturate. Furthermore, this technique involves separate TDD control and HD control loop, to meet both the TDD limit and HD limit. The design procedure of the control loops is discussed. Finally, the proposed scheme is validated in MATLAB-Simulink platform.