Phase-Locked Loop with Inverse Tangent based Phase Detection

In this paper, a novel closed-loop synchronization algorithm is proposed based on the linear phase angle detection. The linear phase detection is performed by the inverse tangent (atan2) trigonometric function, while the frequency tracking is performed by a proportional-integral (PI) loop filter and phase integrator. By using the linear phase detection, the linear phase-locked loop (PLL) is employed, which is simpler to implement and to tune, and which also performs better for large frequency and phase variations when compared to conventional PLL algorithms. Also, the novel technique operates consistently for a whole range of designated PLL crossover frequencies when compared to existing PLL techniques, which makes it a better candidate when higher filtering is required of higher harmonics and measurement noise. When compared with existing algorithms that use atan function for phase angle estimation, the novel algorithm enables the frequency estimation that does not include differentiation, which improves the resulting algorithm immunity to measurement noise and higher harmonics. The novel PLL is tested by simulation and experimental runs.