Active harmonic filtering of islanded converter interfaced generation considering the thermal limits

The high penetration of renewable energy sources (RES) interfaced with power electronics along with the increase of non-linear loads may create power quality problems in distribution systems. Harmonics can be mitigated by applying active filtering techniques using a virtual impedance technique and a set of resonant controllers tuned to the specific harmonics to be compensated. However, these controllers do not usually consider the thermal limits of the power converters, especially those based on the virtual impedance approach. The contribution of this paper relies on adjusting dynamically this virtual impedance to avoid the power converter overloading. The paper includes experimental results to validate the operation of the proposed algorithm.