Distribution network hosting capacity assessment: Incorporating probabilistic harmonic distortion limits using chance constrained optimal power flow

Abstract

The capacity of renewable distributed generation (DG) connected in distribution networks is increasing. Use of power electronic interfaces means DG can inject harmonic currents through the point of common coupling into upstream networks. The limits stipulated in harmonic emission standards may create challenges for accommodating DG. To explore the impact of harmonic regulations on the ability of distribution networks to host DG, this work incorporates harmonic voltage constraints into a network hosting capacity assessment. A novel hosting capacity assessment approach is presented, incorporating percentile‐based harmonic compliance levels as chance constraints over multiple periods into AC optimal power flow. The case study shows that network hosting capacity for DG could be evidently lower under rigorous compliance with harmonic distortion limits, but that relaxation of the risk constraints has significant value. Furthermore, the complex inter‐connectivity between DG sites means that voltage, thermal and harmonic constraints all influence the locational feasibility for DG capacity.

Performance Analysis of a Backward/Forward Algorithm Adjusted to a Distribution Network with Nonlinear Loads and a Photovoltaic System

“…Moreover, variants of harmonic power flow analysis algorithms have been proposed for application in distribution networks, which consider frequency variations associated with DERs and nonlinear loads. Among these, algorithms in the frequency domain stand out for their effectiveness in reducing computational times (2,(8)(9)(10)(11)(12)(13)(14)(15)(16).…”

“…Additionally, considering nonlinear devices in power flow analysis requires models that represent their harmonic nature and take the harmonic interaction between voltage and current into account (8,(13)(14)(15)(16). It is common to use the fundamental frequency-dependent current source model for these loads, which does not consider such harmonic interactions (2,8,(14)(15)(16).…”

“…Additionally, considering nonlinear devices in power flow analysis requires models that represent their harmonic nature and take the harmonic interaction between voltage and current into account (8,(13)(14)(15)(16). It is common to use the fundamental frequency-dependent current source model for these loads, which does not consider such harmonic interactions (2,8,(14)(15)(16). In light of this, other load models may be suitable, such as the Norton equivalent coupled admittance matrix model, as well as proposing or studying the performance of harmonic power-flow solution algorithms that consider the actual conditions of distribution networks.…”

“…Therefore, studies on distribution networks with these characteristics are necessary; they allow, among other things, characterizing the harmonic distortion pollution caused by the high presence of electronic loads and the increasing penetration of PV systems in low-voltage distribution networks (10), which tend to increase power losses and interference in communications while decreasing the lifetime of the installed equipment (14,(17)(18)(19)(20).…”