Control of the input characteristic and the displacement factor of uni- and bidirectional SWISS rectifier for symmetrical and unsymmetrical three-phase mains

This paper introduces a phase-oriented control strategy for the uni- and bidirectional three-phase, bucktype SWISS Rectifier. It allows phase shifted sinusoidal input currents which enable the generation of capacitive or inductive reactive power at the converter´s AC grid interface. Furthermore, the operation of the SWISS Rectifier with unsymmetrical AC mains voltages is analyzed. Modifications of the control structure, allowing constant AC input power or ohmic mains behavior even with unsymmetrical AC voltages are presented. Simulations and measurements taken on a 7.5 kW bidirectional SWISS Rectifier hardware prototype demonstrate the validity of the theoretical considerations.