Photovoltaic Supplied T-Type Three- Phase Inverter with Harmonic Current Compensation Capability

In this paper, a T-Type grid-connected inverter with harmonic current compensation capability is proposed and studied for the on-grid photovoltaic (PV) systems. This idea is based on the modification of the existing photovoltaic inverter control algorithm with the adaptation of active power filter control algorithm. The grid-connected PV inverter has similar topology and control methods as that of the active power filter systems. However, such multifunctional inverters have not yet matured for commercial use and call for more research. In this work, a conventional phase locked-loop algorithm is used to determine the angular position of the synchronous reference of the grid voltages. PV power is estimated and fed into the control loop. Then, the measured currents at the load terminals are proceeded to obtain harmonic current components. The obtained control signals are used to drive the grid-connected T-Type inverter.