Large signal mathematical modeling of three-phase synchronous generator-rectifier systems

Three-phase synchronous generator-rectifier systems (TPSGRSs) with LC filters would exist discontinuous current mode (DCM) at their DC sides in cases of light loading or large filter capacitors contained. It is difficult to establish mathematical model of these generator-rectifier systems operating in DCM. To solve this problem, a new modeling method is proposed by substituting controlled rectifier in series with Boost circuit for diode rectifier in a TPSGRS. Considering the influence of inner resistances of inductances, we establish a new large signal mathematical model of TPSGRSs using switching function and principle of harmonic balance. The new model is compared to detailed simulations as well as physical tests, and is validated to be accurate in capturing large disturbance behaviors of TPSGRS operating in both continuous current mode (CCM) and DCM.