Fast and accurate measurement of power system frequency

With growing applications for protection, control, monitoring and measurement systems for power system applications, the necessity for very reliable and accurate frequency and phase angle measurement of the power system voltage is also growing. This paper describes a linear phase locked loop for three phase systems for precise measurement of the frequency and phase angle of the line voltage. However, the application area of the measurement system may also be extended to single phase systems, which will be shown with a separate paper. The application of the described measurement system is possible for power electronic systems, protection relays and Phasor Measurement Units.