Nonlinear control technique for enhanced synchronization systems: Improving dynamics and noise rejection of...

This work proposes a control technique to significantly improve the performance of synchronization systems used for estimating grid voltage amplitude, phase, and frequency. The method calculates the square root and square of the input signal to form a new compensator. Although it resembles a proportional-integral (PI) controller, it offers enhanced dynamic response and noise rejection. Despite being nonlinear, a comprehensive theoretical analysis shows that design guidelines are similar to those of linear controllers. Notably, this solution offers some of the most significant performance improvements in the recent literature within this research field, but results in only a minor increase in computational complexity compared to widely used linear control techniques. The proposed method is also compatible with conventional phase-locked loop (PLL) algorithms, with numerical simulations and experimental results confirming its effectiveness.