Single-Phase Single_Stage On-Grid Inverter

A single-phase single-stage PWM PV inverter with MPPT and on-grid operation is simulated

To ease hardware implementation, switching should have a fixed frequency and the use of DSP PWM modules require the controller to generate its action in the form of a 0:1 duty. In the attached simulation, the grid angle is detected using an FFT detector. The PV is coupled to the inverter using a capacitor, the capacitor reference voltage is defined by incremental conductance MPPT technique. The PV coupling capacitor voltage is tracking its reference by varying the extracted power via controlling the magnitude of the AC current injected into the grid, the angle of the AC reference current is obtained from the grid angle and the desired power angle (in our model it is set to unity power factor). A current control loop is then used to ensure acceptable tracking of phase and magnitude of the reference ac current. AC current phase shift tracking is also assisted by using a dedicated PI which generates a phase compensation angle.