Input filter design for two-stage matrix converter applied in aero variable-frequency power system

Variable speed constant frequency (VSCF) generation system based on a two-stage matrix converter (TSMC) has advantages in efficiency, power density, reliability and lifetime, thus earning a potential application prospect in aero power supply system. A proper input filter is essential for the TSMC to eliminate high-frequency harmonics and improve input-side performance. However, the design of input filter gets rather difficult, because it is hard to obtain low total harmonic distortion (THD) of input current and high input power factor simultaneously under the high input frequency in aero power system. In aim to solve this problem, a set of design principles is proposed to ensure that the TSMC meets related requirements throughout a given range of load power. The parameter limitations of input filter with different switching frequencies and output power range are summarized, which helps simplify the filter-design process. The analysis results prove that the available parameter range of the input filter turns out to be null, if switching frequency is too low or load power range is too wide. The feasibility and validity of input filter design results is verified via simulation.