Multi‐criteria protection scheme for online element failure detection in shunt capacitor banks

Abstract

This paper deals with a fault detection investigation of SCBs, and it is focused on the faulty phase detection and the number of faulty capacitor units. Unlike previous methods, the proposed method provides a relay decision making criterion which determine the faulty capacitors, and the number of capacitor failures in case of multiple faulty phase conditions. The proposed algorithm is applied on different wye configurations of SCBs considering different protection designs (i.e., fuseless, internally and externally fused units). Since the detection of capacitor failures in SCBs are based on the fundamental phasor component, there may occur a significant delay in decision making in the case of an external short circuit fault in the power system. The aforementioned condition, which will be mathematically proven, happens due to a capacitor discharge after fault clearance. To deal with this condition, a method is proposed by applying an algorithm, in which the fundamental component of the voltage signal is extracted in one cycle. Performance evaluations associated with the proposed method are provided for different fault conditions, fault locations, and different levels of harmonics and, they are further discussed through the implementation of the proposed method in MATLAB environment.

Capacitive making of double‐break vacuum circuit breaker: Transverse magnetic field contacts are superior to axial magnetic field contacts

“…Because of the existence of inductive loads, the operation of an electric power system will generate a large amount of reactive power. Reactive power can harm the normal operation of an electric power system through system voltage deviations and electric energy loss [1]. The switching of capacitor banks is a useful and economical method for reactive power compensation.…”

“…The previous studies of capacitive switching in VCBs can be summarized in three steps: (1) The correlation between restrikes and prestrikes, (2) the prestrike characteristics, (3) the reduction method of inrush currents and the erosion on contacts. At first, researchers mainly focused on the reasons for the restrikes in VCBs when switching off shunt capacitor banks.…”

Shunt Capacitor Bank Fault Detection and Localization Using Sub-Cycle Algorithm

“…The SR approach is based on the application of voltage signals available for unbalanced protection relays. In [18], a comprehensive algorithm was presented that used the coefficients based on capacitor variations to identify the internal faults in the SCB.…”

Beat‐less algorithm based on dual‐frequency compensation in railway traction applications

“…Thereby, the fluctuating power is absorbed, and the DC-link voltage can be smooth without the low-frequency component [4]. However, the hardware solution using the LC resonant filter is of low power density and low reliability [5,6]. Therefore, more efforts have been made on the software solutions to remove the bulky LC resonant filter.…”