Study of the harmonic and interharmonic content in electrical signals from photovoltaic generation and their relationship with environmental factors

The inclusion of renewable energies is associated with harmonic and interharmonic contamination due to the use of power inverters. Thus, several international standards have been developed to establish the admissible distortion levels associated with spectral contamination. However, these standards present limitations: interharmonics are not considered and only present limits for current signals and voltage are dismissed. This work assesses the spectral content introduced by photovoltaic generation in low voltage grids considering the existence of voltage harmonics and interharmonics. Additionally, a multiple linear regression analysis quantifies the effect of sun irradiance and photovoltai cell temperature on harmonic and interharmonic distortion. The analysis is performed in real signals from a photovoltaic generation plant considering different weather conditions. The results prove that the spectral content in photovoltaic generation is variable throughout the day, and environmental factors can reasonably describe the behavior of harmonic and interharmonic distortion.