Proposal of a modular three-phase SEPIC-DCM rectifier for small wind energy conversion systems

This paper presents the theoretical analysis and experimental results from a three-phase SEPIC-type rectifier operating in discontinuous conduction mode (DCM). The rectifier is suitable for applications in the electronic energy processing of small wind energy conversion systems based on permanent magnetic synchronous generators. The rectifier is capable of providing high power factor without the use of input current sensors and current control loops because in DCM SEPIC converter has the characteristic of emulating a resistor. Thus, the input currents have the same shape of input voltages and they are in phase with each respective voltage. Moreover, the rectifier has the benefits of simplicity in the control system and PWM scheme. Finally, experimental results from a prototype with 220V input voltage, 200V output voltage, 50kHz switching frequency and 1.5kW output power are also presented.