Average and hysteresis current-controlled three-phase three-level unity power factor rectifier operation and performance

摘要

Three-phase three-level rectifier (TPTL) is popular in present days for high-power application owing to its low blocking-voltage stress on the power switches (half of dc-link voltage). Such a rectifier can also operate as unity power factor (PF) converter as presented in this work. The rectifier input current controller can be operated with either fixed frequency or random frequency both with their advantages and shortcomings. In this study, the current controller is implemented with: (a) conventional hysteresis current control (random frequency) and (b) average current control (fixed frequency). The design issues and the performance of the two current modulation strategies are investigated and compared. Rectifier performance parameter, that is, THD and PF are evaluated and confirmed through hardware prototype results.