Maximizing DG Output Power Using Mul-tilevel Transformerless Inverter

Abstract

This thesis introduces a new control approach for three phase unbal-ance problem in distribution networks. New topologies have been presented in order to detected the highest consumption, adequate control the P-Q outputs and finally applying a short circuit protection to the system where means preventing the system from injecting current to the grid during a short circuit error case. The approaches adopted in this model is trying to decrease the unbal-ance limit by comparing the three phase currents and detect the high-est value. This indicates a highest load consumption based on that and sends a control signal to a power switch connected to the defect-ed phase in order to inject the inverter output through it. A new to-pology also is presented for active and reactive power controller which is the responsible for delivering the power according to the grid needed conditions. But because this system is single phase sys-tem, an imaginary three phase system was created in order to apply parks transformation required to perform P-Q control.