Virtual Flux Oriented Sensorless Direct Power Control of QZS Inverter Connected to Grid for Solar PV Applications

Impedance source inverters (Z-source and Quazi-Z-source (QZS)) are the promising converter topologies in the future because of the buck, boost and buck-boost modes of In this paper, three phase voltage sensorless grid connected inverter is proposed to inject Maximum Direct Power. The new system uses the Virtual Flux Oriented Control (VFOC) algorithm for control and virtual Flux (VF) estimation method for grid The complete Virtual Flux direct Power control (VFOC-DPC) the performance and operation of the proposed system to the conventional DPC algorithm is presented. Proposed strategy is also investigated under predistorted and unbalance grid VFOC-DPC provides numerous benefits mainly providing sinusoidal line currents when the supply voltage is Simulation results are presented under unbalanced and existing harmonic content in the grid voltage to verify the VF of grid voltage. Tracking of active- reactive power is done with current control loops providing good steady state transient response to step change in reference.