Abstract: The massive integration of photovoltaic systems into low-voltage grids introduces power quality challenges due to harmonic distortion. This article presents a probabilistic assessment using Monte Carlo simulation based on experimental measurements taken over seven consecutive days of three commercial inverter technologies, yielding 5,168,640 data points with one-minute resolution. The results reveal a 34-fold disparity in total harmonic distortion (THD): pure sine wave inverters exhibit 1.00% ± 0.20%, complying with IEEE 519-2014, while square-wave and modified-wave inverters exhibit 30.10% ± 2.10% and 34.60% ± 4.30%, exceeding regulatory limits. Through 10,000 simulations on the CIGRE European LV Benchmark network, it is demonstrated that nodes with high-quality inverters have a zero probability of violation, while low-quality inverters have a probability exceeding 97%. For a 9.7% PV penetration rate, the probability of violation reaches 8.5%. Penetration limits of 7.5% are established, or the proportion of high-quality inverters should be increased to 85–100%.

Keywords: Power quality, Total harmonic distortion, Photovoltaic inverters, Monte Carlo simulation, probabilistic analysis, Distributed generation, Low-voltage networks

Pages: 252-262