Operation of parallel Unity Power Factor Passive Front End rectifier for PMSG based offshore wind turbine system

Increased size and capacity of individual wind turbine has posed a major challenge for high power conversions. For this scenario advanced multilevel converter topologies and parallel operation of Active Front End (AFE) rectifiers are gaining popularity. But there are issues on reliability and complicacy of control and operation of active power electronic devices at such high power. The Passive Front End (PFE) rectifiers are rather simple in control and more suited as front-end rectifiers for higher power. Though the control is fairly simple, the PFE comes with disadvantages of harmonic distortions and thus low power factor. This study proposes the parallel operation of simplistic PFE rectifier with bidirectional switches transmitting power to dc-bus for HVDC application with near Unity Power Factor (UPF) characteristics and reduced current stress on the diodes and switches. This paper is organized in separate sections with introduction in section I. Section II has a comparative study of the AFE and PFE. Section III discusses proposed system description and controller design. Result evaluation of simulation carried out in co-simulation environment of PSIM and MATLAB/Simulink© software are discussed in Section IV followed by conclusion in Section V.