Research on the voltage filter method for AC excited variable speed constant frequency generator

Power quality of AC excited variable speed constant frequency (VSCF) generator, which adopts cycloconverter as exciting device, canpsilat meet the need of power system well because of harmonics in the output voltage of cycloconverter. So, how to reduce harmonics is an important problem for VSCF generator. A new active power filter method named synchronous filter method is presented in this paper, which based on the analysis of the output voltage of cycloconverter. Compared with other filter methods, synchronous filter method has the characters of simple calculation and obvious effect. This filter method may be adapted to the situation that the output frequency of cycloconverter is changed continually and even it is DC voltage. It can improve the output voltage quality of an AC excited VSCF generator obviously.