The amplitude of harmonic currents of the cycloconverteris low relative to fundamental current under the condition of
low-frequency outputs, and external impedance can be seen as
a filter behind cycloconverter with a small time constant. For
the output current of cycloconverter, the influence of
harmonic components is negligible and only fundamental
components are considered. Substituting (1) and (1 1) into (9):