Voltage Sensor-Less Design for Single-Phase Grid-Tied Inverter for PV Power

This thesis explores the concept of relying on grid impedance to act as a filter for a single-phase photovoltaic (PV) inverter system. The prospect of this idea implies the possible removal of the inverter filter. For this system without the inverter filter, a voltage sensor-less design is proposed, relying on the inverter current and a PQ reference. The prospect of removing the inverter filter removes stability concerns associated with this component. The control for this system also avoids implementing a phase locked loop (PLL), a component that also has stability concerns. In this thesis, this novel controller with current feedback utilizing voltage reference for grid synchronization is presented. By not implementing the filter or the PLL, a more stable system can be implemented. With this controller, sinusoidal current is obtained by relying only on the grid side. Simulation results are provided to show the capability of the proposed controller of decoupling the output real and reactive power and synchronizing with fluctuations of grid frequency.