A new input-voltage feedforward harmonic-injection technique with nonlinear gain control for single-switch, three-phase, DCM boost rectifiers

A new input-voltage feedforward harmonic-injection technique for a single-switch, three-phase, discontinuous-conduction-mode boost rectifier is introduced. With this technique, rectification with a low total harmonic distortion that meets the IEC555-2 requirements can be achieved. In addition, the rectifier shows an excellent transient performance which dramatically reduces the rectifier´s output voltage overshoots during line-voltage step-up transients. Moreover by the addition of a nonlinear gain-control circuit, the DC gain of the DCM boost rectifier at light load is adaptively reduced so that the stability of the rectifier at light load is achieved. The performance of the proposed injection technique was verified on a 6 kW prototype rectifier.