Review of Recent Grid Synchronization Techniques and Phase-Locked Loops for Power Converters

Abstract

AbstractIn this paper, emerging grid synchronization techniques for power electronic converters are reviewed. In recent years, there has been a significant increase in the penetration of Distributed Generation (DG) in modern grid architecture. DGs such as solar photovoltaics, wind turbines are interfaced with the grid by way of power electronic converters. For ideal operation, these power electronic converters should be properly synchronized with the grid, i.e. there should be minimal difference between the grid and converter output voltage parameters such as frequency, phase and magnitude, in order to avoid abnormalities such as current transients. Frequency and phase should be tracked especially for driving internal control systems of the power electronic converter. Recent research has geared towards maintaining this synchronization – even during abnormal grid conditions – and exploring techniques which either advance or move away from conventional phase locked loop (PLL) approach. Through this review, modern advances in grid synchronization methods for power electronic converters will be highlighted, and the trajectory for subsequent research shall also be predicted.KeywordsGrid synchronizationPhase-locked loop (PLL)Power electronic converterPhase angle detection