Inverse Clarke Transformation based control method of a three-phase inverter for PV-Grid systems

A photovoltaic (PV)-Grid System integrates electric energy generated by PV modules and a grid. A Maximum Power Point Tracker (MPPT) is required due to PV characteristic. It will force the PV modules produce maximum power in the DC voltage. It is needed an inverter to convert DC into AC voltage and to match the grid voltage. A standard inverter topology used in active filtering is functioned to inject harmonic and reactive power components but it must be able to transmit active power component in PV-Grid System. Instantaneous power concept is often used to control an active power filter due to its simplicity. In this paper, a control method for a three-phase three-legs inverter is proposed. This is based on inverse Clarke Transformation. The inverter is implemented by Voltage Source Inverter (VSI) that is operated as a controlled current source by using a current controller. Inverter output currents will be compared to references produced by inverse Clarke Transformation. To achieve power equilibrium, the voltage of the DC-link is kept constant. The obtained results have proven that all the power generated by the PV modules can be transmitted into the grid.