Development and analysis of Swedish residential LV grid with heat pump, PV, EV, and battery storage. : Study of the effect of electrification of Swedish villas in low voltage radial feeder system.

Sammanfattning

This degree project examined the technical impacts of integrating heat pumps (HPs), rooftop photovoltaic (PV) systems, electric vehicles (EVs), battery energy storage systems (BESS), and vehicle-to-home (V2H) operation into a residential low-voltage (LV) radial distribution network in Eskilstuna, Sweden. The LV network was modeled in MATLAB, and hourly alternating-current power-flow simulations were performed using MATPOWER. Mixed-integer quadratic programming (MIQP) was used to optimize scheduling for battery and V2H charging and discharging. Simulation of EV mobility was generated from a random sample of driving behavior data in Sweden using a Monte Carlo method. Ten cases for each of the four representative seasonal weeks were evaluated based on six performance indicators: far-end voltage, voltage profile along the farthest feeder, total system losses, aggregated peak load, PV self-consumption (SC), and PV self-sufficiency (SS). The results indicated that both the magnitude and duration of voltage violations, along with system losses, increase as the electrical distance from distribution transmission increases. The result also shows that HP and EV dumb charging caused undervoltage and increased peak load in winter, while rooftop PV caused overvoltage in spring, summer, and autumn. Both BESS and V2H improved performance indicators relative to the all-electrification case without storage. However, BESS generally performed better than V2H across most metrics and seasons. This study concluded that location, technology mix, and storage availability jointly shaped the grid impact of residential electrification.