Parameters Uncertainty Immunization of Global Synchronous Pulse Width Modulated VSIs with Round P&O Algorithm

This letter proposes a closed-loop scheme for global synchronous pulsewidth modulated voltage source inverters with round perturbation and observation (R-P&O) algorithm to immunize the parameters uncertainty, e.g., line impedance and filter impedance variation. In specific, the rms value of measured total current harmonics at point of common coupling will be periodically sent to each inverter as feedback signal using the low-cost narrowband communication system. Then, the inverters will assume the R-P&O scheme to correct the phase shift angles among pulsewidth modulation carriers for intentionally minimizing the total current harmonics. Doing so, the closed-loop scheme can achieve the expected performance even under the severe parameters' variation. The experimental results verified the performance of the proposed method.