Abstract
Abstract:
The cascaded NPC/H- bridge inverter is first analyzed by
establishing a new switching model based on a derived
control law. From the developed switching model, a
general model is obtained using state space technique. A
new and accurate average model is developed using abc
to dqo transformation technique. Finally small signal
model is obtained by linearizing all the state variables
around their quiescent operating points. The small signal
model is used to study the effects of various control
feedback variables on the dynamic performance of the
Grid connected system. Feedback control scheme is
designed to improve the dynamic response of the system.
The system with the proposed control technique also
achieves sinusoidal grid voltage and current output with
low THD which is a preferred characteristic for any
power injected to the grid. Simulation results are provided
to validate the analytical models