Abstract:
In conventional model predictive current (MPCC) only one voltage vector is chosen
and applied through one control cycle by using the discrete time system model. The
selection of the voltage vector is based on minimizing a cost function. However, due
to the restricted number of switching states which produced by three phase micro
inverters, this will produce high current harmonics and limit the steady state
performance. To enhance the effectiveness of the conventional MPCC, this research
proposed an improved MPCC with duty ratio optimization for three phase grid tie
micro inverter. The proposed strategy divides the one control period into two sub
periods for two voltage vectors. This strategy uses the current error minimization
principle to obtain the duration of the chosen voltage vectors. The simulation results
prove the performance of the proposed MPCC in obtaining better steady state
performance and reducing the total harmonic distortion of current to 0.77%.
