The invention belongs to the technical field of static frequency
converters, and provides a coupled
harmonic current filtering method and
system for an SFC
rectifier, and the method comprises the steps: firstly carrying out the
Fourier transform analysis of a current
signal and a
voltage signal, extracting a coupled
harmonic current component in the current
signal, and determining the frequency and amplitude of the coupled
harmonic current; constructing a correction
transfer function according to the extracted
coupling harmonic current components; superposing the correction
transfer function and a preset basic
transfer function to obtain a total transfer function; and finally, according to the obtained total transfer function, changing the equivalent
inductance and
capacitance values of the filter circuit, and filtering the current of the static frequency converter
rectifier.
Coupling harmonic current parameters are accurately extracted through a
harmonic analysis unit, a constructed correction transfer function can be matched with specific
coupling harmonic current in a targeted mode, and the defects that an existing filter is high in universality and poor in pertinence are overcome. The influence of harmonic
coupling current is considered, and the filtering effect is improved by correcting the transfer function of the existing filter.