Efficacy of a Smart Photovoltaic inverter as a virtual detuner for mitigating Network Harmonic Resonance in Distribution Systems

Abstract As the grid is becoming smarter, more challenges are encountered with the integration of Photovoltaic plants in distribution systems. The real power generation varies based on the insolation from the sun. As a result, the fluctuations in voltages are seen as transient adversaries in the system causing the Photovoltaic inverters to trip. Smart Photovoltaic inverters nowadays are equipped with specialized controllers for exchanging reactive power with the grid based on the available capacity of the inverter, after the real power generation. With the ability of operation in VAR mode, Smart Photovoltaic inverters could regulate the voltage based on volt/VAR control, facilitate the power factor correction of the local loads and provide VAR support to ride through the voltage deviations during faults. Although the research that are undergoing are pertaining to all the aforesaid applications of Smart Photovoltaic inverters, employing a smart Photovoltaic inverter for resonance mitigation is a novel approach. U.S. based standard IEEE 519 for power quality describes the network resonance as a major contributor that has an impact on the harmonic levels. This paper proposes a new application in utilizing a Smart inverter to act as a virtual detuner in mitigating network resonance, based on the VAR mode control strategy with anti-windup and droop characteristics scheme that are incorporated with the design of Smart inverters. This novel application would further serve as a pioneering approach for researchers and planning engineers working in distribution systems as the grid gets more and more smarter.