A new Single-phase PLL based on the input voltage magnitude estimation

Many automatic control applications such as wide scale power grid management and local power conditioning rely on the fast and accurate detection of the voltage signal phase and amplitude. These information are almost all the time given by the Phase –locked Loop (PLL) systems and can be single-phase or three-phase and have many different structures. Many single-phase PLLs core structure are based on the regulation to zero of the voltage direct component in the rotating d-q frame obtained through the Park-transform. Their accuracy and dynamic rely on how quick and accurate the second voltage’s component in the static α-β frame is estimated. This paper presents a new single-phase PLL structure, also based on the same core structure as described before, but implementing a novel voltage β-component generation. A brief review of some single-phase PLLs is made, then the proposed novel PLL structure is detailed and its performance is compared with that of the other PLL’s taking into consideration the following signal disturbances: amplitude variations, phase step variation and frequency fluctuations as well as harmonic distortion.