Dear Manash Mishra:

Phase-locked loop (PLL) is commonly used for three-phase grid-connected inverters to obtain the information of grid synchronization, and PLL dynamics are the key factors for stable operation of the inverters. Yup, it's possible to operate PV inverter in PLL-less. I hope these given reseach papers will help you to understand well about PLL.

https://ieeexplore.ieee.org/document/9094906

https://ieeexplore.ieee.org/document/7972423

https://ieeexplore.ieee.org/document/9082386

Article PV inverter with decoupled active and reactive power control...

Best Regards

Dear Manash Mishra ,

I have been researching virtual inertia control strategies for over three years. I recommend visiting the synchronverter strategy, which does not require PLL for synchronization. The internally generated angle can serve as an angle reference for the rest of the parallel operating inverters.

Please refer to my recent review article for better insights.Article Synchronverter: A Comprehensive Review of Modifications, Sta...

Regards.

Thank you sir