Partial sine wave tracking dual mode control topology for a single-phase transformerless photovoltaic system

A unique high efficiency photovoltaic（PV）system is presented. It uses partial sine wave tracking for a pulse-width modulation（PWM） boost converter as well as a full-bridge inverter. The boost converter and full-bridge inverter are connected via a compact intermediate film capacitor（i.e. non-smoothing DC link stage）. PWM switching is activated by a dual mode control technique. In the proposed topology, simultaneous switching of both power conversion stages is avoided and therefore this increases the power conversion efficiency. The distinctive operating principles of these two power processing stages are discussed and analyzed with the experimental results for single-phase loading of the PV system.