A Method for Real-Time Grid Signals Analysis

This paper introduced a method to track the phase angle, frequency, and amplitude of the real-time grid signals, which is of great importance for many applications in power systems such as power quality and protection. The proposed scheme is based on a phase-locked loop (PLL) and a first order control system. This method is simple and offers a high degree of immunity and insensitivity to power system disturbances, harmonics, and other types of pollutions that exist in the grid signal. Stability analysis with Bode criterion is presented and digital time domain simulations confirm the validity of the functions of the method.