Review and results of studies of the harmonic composition of the current consumed by low-power frequency converters, as well as methods and devices to reduce their negative impact on power supply systems

Abstract

The ACS150 frequency Converter was chosen as the object for experimental research. On the basis of the measurements it is concluded that in the spectral composition of current drawn by the frequency Converter, in addition to currents the main harmonic component is dominated by currents 5, 7, 11, 13, and 17th harmonics, i.e. harmonic components of odd non-multiple of three. Currents 3, 9 and 15 th harmonic components are also present in the spectral composition, but their value is much smaller. Also, based on the data obtained, it can be argued that with a decrease in the frequency of motor speed control and the load value of the frequency Converter, the number of pulsations on the current waveform increases, as a result, there is an increase in the values of the higher harmonic components and an increase in the value of the total harmonic components of the current. The main contribution to the increase in the index of the total harmonic components of the amperage with a decrease in the load of the frequency Converter and the output frequency of the motor speed control is made by odd harmonic components of the amperage multiple of three, at the same time harmonic components of the amperage non-multiple of three, namely the 5th and 7th order, are not subject to change. A brief review of technical solutions aimed at improving the electromagnetic compatibility of asynchronous frequency-controlled drive is given. In particular, such solutions as increasing the number of semiconductor switches used in inverters, improving control modes, the use of special separation transformers, passive (resonant) and active filters are noted.