Robust Phase Synchronization in Ev Powertrain Converters: a Comparative Study of Pll Techniques Under Dynamic Grid Disturbances

Abstract

The increasing adoption of electric vehicles (EVs) and the development of EV charging infrastructure present significant challenges in power converter stability, particularly under fault conditions and dynamic grid disturbances. This paper investigates the performance of advanced phase-locked loop (PLL) techniques-an enhanced SOGI (E-SOGI)-PLL, adaptive filter-PLL (AdF-PLL), and average filter (AvF-PLL)-integrated within EV powertrain converters to enhance grid synchronization, transient stability, and power quality. A comparative analysis is conducted based on various fault scenarios, including voltage sags/swells, line-to-line faults, and harmonic distortions. The results demonstrate that the AdF-PLL and AvF-PLL outperform traditional methods like SRF-PLL and E-SOGI-PLL in terms of phase-tracking speed, harmonic filtering, and settling time. These advanced PLL techniques provide superior adaptability to frequency variations, improve stability under dynamic loads, and offer robust harmonic management, ensuring the efficient operation of EV charging stations. Stability analysis is performed using a Lyapunov function and a systematic procedure for tuning control parameters to improve robustness. The analysis also evaluates PLL bandwidth's impact on power converters' stability. This paper presents a comprehensive stability analysis, along with control design recommendations and compares advanced PLL techniques' performance, supported by theoretical insights and practical case studies. The findings highlight the potential of these PLL methods to optimize the performance and reliability of EV power converters, particularly in fault-prone and grid-disturbed environments.