A transformada de Fourier janelada aplicada na avaliação espectral para chaveamento de banco de capacitores em sistema de transmissão

Abstract

The use of shunt capacitor banks is an effective methodology to increase voltage levels in order to meet the demand for power request by the electric power system. The reactives present in the system are compensated through the insertion of capacitive power by the banks. However, at the moment a capacitor bank is switched in operation, high magnitudes of overvoltages and transient overcurrents occur. These voltages and currents can cause malfunctions in the equipment installed near the bank. Therefore, a study is necessary to understand the behavior of these transients caused by the energization of capacitor banks. In this work, simulations are performed of an actual power system and its main capacitor bank maneuver conditions, using the ATP (Alternative Transients Program) software. Then using the Matlab software, the resulting signals are subjected to an evaluation of their energies through the Windowed Fourier Transform, which will provide information on the time and frequency of the analyzed signals. According to the results found in this paper, it was possible to visualize a frequency band characteristic of capacitor bank switching in electrical power systems, and their respective alterations to different types of switches.