Impacts of three-phase power converter operating modes on harmonic emissions in distribution networks: harmonics emission within 2–9 kHz

The increasing penetration level of power electronic converters in distribution networks has raised concerns about the impact of these converters on the power quality of the grid. Pulse-width modulated (PWM) voltage generated by these converters creates higher frequency current distortion around both its switching frequency and multiples, which could be circulated through the grid. Consequently, it is essential to understand and analyse the frequencies and amplitudes of these harmonics in terms of load parameters. Thus, this study proposes an analytical method to find the inverter current harmonics generated by PWM signal in terms of the load parameters, including its power factor. The impact of the load power factor on the inverter current harmonics has been found to be significant using the derived equations. Simulation and practical results have confirmed the accuracy of the obtained equations to calculate the inverter current harmonics. The mathematical modelling is important for harmonic analysis of converter within 2–9 kHz range as a new standard has been developed by IEC SC77A, WG1 committee.