Evaluation of Decentralized Voltage Harmonic Mitigation through DRES converter active filtering capability

The increased penetration of Converter-Interfaced Distributed Renewable Energy Sources (CI-DRES) has posed power quality challenges into the distribution system. In the future CI-DRES may have the responsibility to cope simultaneously with several issues. One function that has already been presented in the literature, but has not yet been included in Standards, is the operation of the DRES converters as active harmonic filters. This paper firstly develops an active filtering control for the CI-DRES, taking into account its thermal limit. This parameter is important, since DRES are already prescribed by Standards to participate in the voltage regulation process by providing reactive power. If the CI-DRES operates also as active filter, it may exceed its thermal capacity. Secondly, the decentralized operation of CI-DRES is evaluated in the CIGRE Benchmark LV distribution system by considering several scenarios of DRES/Non-linear loads penetration and mixture. Time-domain (TD) simulations are carried out in PowerSim Software to demonstrate the contribution of each CI-DRES in the active filtering process. The derived conclusions will serve as a basis for the development of a new coordinated algorithm, so as the CI-DRES can mitigate properly voltage harmonic distortion (HD) in the most efficient techno-economic way. In this way, the active filtering can be treated as a new ancillary service to be introduced in respective markets.