Time-Domain Modeling of a Distribution System to Predict Harmonic Interaction Between PV Converters

Abstract

Due to the interaction converter control, pre-existing distortion and grid impedance, the harmonic levels caused by renewable energy sources are continuously changing, and their assessment requires the use of dedicated computer models. Several time-domain models have been proposed to carry out this analysis, however, they fall short of at least one requirement: either they do not provide accurate results, or they require an excessively long simulation time. This paper presents a novel time-domain model to address the gap described above: the proposed model employs average functions and a novel switching emulator. Therefore, it is referred to as "average model with switching emulator" (AMSE). The proposed model is compared with existing models, and the results indicate that the AMSE meet both requirements stated above, as it accurately represents harmonic distortion while reducing significantly the simulation time. The second part of the paper discusses mitigating solutions to harmonic amplification in systems with a high penetration of VSCs, and shows the effectiveness of using an active filter to reduce harmonic levels in system experiencing resonance conditions.

RETRACTED: Harmonics mitigation in hybrid shunt active power filter connected renewable energy source using an intelligent controller

“…However, those models have been demonstrated to be the most disappointment-inclined segments in a power electronic circuit. For mitigating the harmonics in the electrical power system, a novel time-domain model that incorporates the average functions and a novel switching emulator named as average model with switching emulator have been introduced by Todeschini et al (2019). The authors additionally have displayed a high penetration of voltage source converters for relieving the harmonic amplification in the second part of the paper.…”

Novel time‐domain average model for harmonic current prediction in photovoltaic and wind power units

“…The performance of the three time‐domain models is further investigated by inserting background distortion in the grid 6 . The following harmonic orders were added to the fundamental component: 5% amplitude for the fifth harmonic and 4% amplitude for the seventh harmonic.…”

“…However, when used to represent a 1059‐MVA high‐voltage direct current (HVDC) system, the average‐value model displayed a THD v of 0.28% on the secondary side of the converter transformer, whereas the DM provided a THD v of 1.24% (ie, a discrepancy of 0.96%). Todeschini et al 6 proposed an enhanced SM that uses a controllable voltage source to represent active elements. A switching emulator was used to incorporate the harmonic content in the current and voltage waveforms.…”

“…Although the majority of SMs are used to perform transient stability studies, 15 it is possible to find SMs related to harmonic estimation. 6,16 Peralta et al 16 presented an average-value model with switching functions. This SM includes harmonic content from modulation control.…”

Data‐driven robust extended computer‐aided harmonic power flow analysis

“…Indeed, the report by CIGRE [30, 31] clearly reveal that harmonic interactions – ‘auto’ and ‘cross’ sensitivities do exist. The field measurements [8] conducted by the same authors also confirm this.…”