Modular Digital Power Factor Correction for Aerospace Applications

This work focuses on development and implementation of i) a 7.5kW, three-phase, modular, very compact, light-weight, and fully digitally controlled boost rectifier unit with active power factor correction (APFC) and ii) a 15kW, a 22.5kW and a 30kW active PFC boost rectifier units by combined parallel operation and electrical interleaving of the two, three and four 7.5kW modules, respectively. The control algorithms for the units and signal conditioning of feedback signals are realized in all-digital form using Field Programmable Gate Arrays (FPGA's). This allows for great flexibility to adapt and configure the units easily for variety of operating conditions encountered in aerospace applications. The key attributes to volume and weight reduction are i) the use of specialized nanocrystalline magnetic material for the boost inductors, ii) the high switching frequency capability and iii) electrical interleaving of the individual rectifier units. The proposed scaleable boost rectifier yields an industry-leading power density and efficiency. The experimental results show that the performance of the boost rectifier units exceeds the stringent power quality specifications for the aerospace applications.