Current Harmonics Generated by Multi-power Converters in Distribution Networks in the Frequency Range of 2-9 kHz

Power converters generate current harmonics due to their nonlinear characteristic and switching function. Among these harmonics, 2-9kHz current harmonics have not been covered in the existing standards, so regulations are being developed by IEC standardisation committee SC77A, WG1. This paper explores the current harmonics generated by converters in the frequency range of 2-9kHz in a multi-converter distribution network. So, the impacts of different converter components such as a rectifier and an inverter switching function are analysed on 2-9kHz current harmonics using experimental and simulation data. Next, analytical equations for estimating 2-9kHz current harmonics in the multi-converter condition are developed. Moreover, the harmonic cancellation in the range of 2-9kHz is studied at the system level considering different operating power and load power factors for the converters. The outcome of these investigations can be utilised to estimate the current harmonic emissions in the frequency range of 2-9 kHz in a multi-converter network. This paper also provides valuable information for compatibility development in 2-9 kHz frequency range concerning IEC SC 77A standardisation committee at a system level.