Improvement of PV unit hosting capacity and voltage profile in distorted radial distribution systems via optimal sizing and placement of passive filters

In this paper, firstly, optimal sizing and placement of photovoltaic-based distributed generation units (PVDGUs) and passive
harmonic filters (PFs) are proposed to improve both the PVDGU hosting capacity and bus voltage profile of the distorted
radial distribution systems. The objective of the proposed approach (PA) is defined as minimizing the rms deviation and total
harmonic distortion of the bus voltages while maximizing the hosting capacity. Its constraints are considered as bus voltage
total and individual harmonic distortion limits placed in IEEE standard 519, permissible bus voltage rms intervals, and the
numbers and total powers of the PVDGUs and PFs. Secondly, it is aimed to investigate the performance of the PA on the
improvement of the hosting capacity and voltage profile. Thus, for the modified IEEE 33 bus test system containing nonlinear
loads, it is comparatively evaluated with a traditional PF planning approach (TA) based on minimization of the total voltage
harmonic distortion. Finally, the effects of the harmonic analysis algorithm and PVDGU harmonic model preferences on the
solutions of both approaches are also analysed. One of the major conclusions obtained from the analysis is that PA achieves
significantly higher PVDGU hosting capacity while providing total voltage harmonic distortion mitigation performance very
close to TA. In addition, PA achieves almost the same hosting capacity for all considered harmonic models and harmonic
analysis algorithms. However, this is not the case for TA.