Measurement quality enhancement using digital filter in power grid integrating TCSC

Measurements of the instantaneous amplitude and phase angle of the fundamental current or voltage components and frequency that may be needed in three-phase power grid instrumentations/meters and relays may be affected by several encountering disturbances. These disturbances may be due to an abrupt heavy load changes and post-faults resulting in frequency deviation, DC offsets decaying, and harmonics especially in the power grid including TCSC devices. To study these effects on the quality of measurements, this work presents a new approach using the data generated by Simulink/MATLAB software. The obtained simulation results show that the unwanted DC offset and harmonics as well as sub-harmonics can be removed completely by conventional filters such as anti-aliasing and DFT filtering but they can be eliminated by inserting before DFT algorithm a digital filter.