The Conception of a Controlled Trigonometric Phase Locked Loop Working Under Grid Anomalies Conditions

In a Grid-Connected Converters system, a phase angle grid detector is important in the synchronization of power electronics-based converters, also to control the power demands and compensate the harmonics propagating in the grid for filtering purposes. The phase-locked loop (PLL) follows continuously the fundamental frequency of the grid’s voltage in a correct way and in real-time. Several types of PLLs have been introduced in the literature to achieve good synchronization under normal and abnormal grid voltage conditions. This study proposes a trigonometric three-phase PLL, associated with a Proportional integral controller, whose performances are analyzed under various disturbances that can occur on the grid: a combination of three-phase voltages unbalanced in amplitude, a phase jump and non-sinusoidal grid voltages. It’s evaluated in the transient and steady-state to conclude its validity. Correlatively, the proposed PLL offers a possibility of phase control by imposing an output signal shifted with the grid’s voltages.