Transient analysis resulting from shunt capacitor switching in an actual electrical distribution system

The quality of electric power has been a constant topic of study, mainly because inherent problems to it can bring great economic losses, mainly in industrial processes. Among the various factors that affect power quality, those related to the transients originated from capacitor bank switching in the primary distribution systems must be highlighted. In this work, the characteristics of the transients resulting from the switching of the utility capacitor banks are analyzed, as well as factors that influence their intensities. The conditions under which these effects am mitigated can then be investigated. In addition, a spectral analysis of the current and voltage waves is made. This procedure can reveal the harmonic component, which can affect the operation of control and protection equipment, as well as sensitive loads of the industry. A circuit that represents a real distribution system, 13.8 kV, from CPFL (Cia Paulista de Forca e Luz-a Brazilian utility) was simulated through the software ATP (Alternative Transients Program) for purposes of this study.