Modelling and analysis of harmonic emissions from grid-to-vehicle (G2V) charging

Description

Master's Thesis:

Authors: Junejo, Shafeo, VTT.

Supervisor: Pouresmaeil Edris, Alto University.
Thesis advisor: Muhammad Faheem & Baranauskas Marius, VTT.

Major/Subject: Energy Systems and Markets

Degree programme: Master's Programme in Advanced Energy Solutions
Kehittyneiden energiaratkaisujen maisteriohjelma
Magisterprogrammet i avancerade energilösningar


Abstract: The rapid electrification of road transport is reshaping low voltage (LV) distribution networks, where fast charging stations have become both enablers of decarbonisation and new sources of harmonic distortion. This thesis investigates how measured harmonic emissions from DC fast chargers influence voltage quality, neutral current behaviour, and practical hosting capacity on a representative Finnish LV feeder. The study applies a measurement-based simulation method in which harmonic magnitudes and phase angles, obtained from a controlled fast charging session at VTT’s TATABE laboratory, are reconstructed into three phase time domain current injections. These are then applied to a 20/0.4 kV network model built from verified component data. The analysis focuses on harmonics up to the 50th order, evaluating how different charging combinations affect voltage total harmonic distortion (THDv), current distortion (THDᵢ), and neutral conductor loading. Results show that simultaneous operation of several chargers amplifies low order voltage distortion at the point of common coupling, while sequential activation yields smoother harmonic progression with neutral currents increasing almost linearly as more vehicles connect. Comparison with single charger baselines confirms that phase angle diversity among individual devices plays a critical role in harmonic reinforcement or cancellation. Overall, the findings provide a traceable link between real charging behaviour and distribution level power quality, supporting data driven assessment of harmonic hosting limits under IEEE 519 and EN 50160 criteria. The work offers practical guidance for Finnish DSOs and infrastructure planners integrating high power chargers into LV networks.

Period	21 Nov 2025
Degree of Recognition	International