Position sensorless surface-mounted permanent-magnet synchronous generator and its application to power DC microgrid

This study presents a position sensorless surface-mounted permanent-magnet synchronous generator (SPMSG) and its application in powering DC microgrid. The derated characteristics of a PMSG with different AC-DC converters under brushless DC generator (BDCG) mode and the conventional switch-mode rectifier (SMR) mode are first comparatively assessed. Then a PMSG followed by three-phase three-switch Vienna SMR is established. Good operation performance is achieved via the proposed robust current and voltage control schemes. Second, a position sensorless control scheme based on observed extended back electromotive force (EMF) for the SPMSG followed by Vienna SMR is developed. The generation characteristics are enhanced by the developed starting and back-EMF angle tuning schemes. Third, a single-phase three-wire load inverter with the proposed novel robust waveform tracking control scheme is developed to yield good AC 220 V/110 V output voltage waveforms under unknown and non-linear loads. Some experimental results are provided to demonstrate the operation performances of the established SPMSG system in conventional generator with fixed output voltage and wind generator. More specifically, the BDCG mode and the SMR mode for operating a PMSG are experimentally evaluated.