Emission Measurement of a Solar Park in the Frequency Range of 2 to 150 kHz

Abstract

Although a few years have passed since the first electromagnetic compatibility problems occurred in the frequency range of 2 to 150 kHz, but we still lack fundamental standards, especially related to emission, that would ensure electromagnetic compatibility. Our aim was to get a better picture about the emission of a solar inverter and also about how disturbances generated by more inverters spread and aggregate on the grid. Thus, based on on-site measurements, this paper investigates the non-intentional supraharmonic emission (both current and voltage) of a solar park that consists of a total of 50 individual PV (photovoltaic) modules and inverters. Supraharmonic voltages and currents were measured at three locations: at one individual PV unit, at a busbar collecting the production of ten PV units and at the transformer, which connects the park with the grid. It was shown that the aggregation of these disturbances is a very complex process, but supraharmonic currents are more likely to flow between the inverters than into the grid. Another important result is that an alteration in production does not significantly change emission levels.