An active islanding detection method without destabilizing the system gives the advantage of accurate decision and the capability to keep the micro-grid energized while islanding occurs. Harmonic and perturbation current injection are such active methods, but none in the literature has discussed about islanding detection in multi-inverter systems. This paper proposes an active islanding detecti...

(Received: October 30, 2011; Accepted: December 8, 2011) Abstract: This paper presents a novel technique for transformer differential protection to prevent incorrect operation due to inrush current. The proposed method in this paper is based on time-frequency transform known as the Wavelet transform. The discrete Wavelet transform is used for analysis the differential current signals in time an...

In this paper we present a combinatorial scheme based on hidden Markov models (HMM) and wavelet transform (WT) to discriminate between magnetizing inrush currents and internal faults in power transformers. HMMs are powerful tools for transient classification which compute the maximum likelihood probability between training and testing data signals for identification. The WT is employed to extra...

Protective relays are installed in generation, transmission, and distribution system for detection, classification, estimation of faults. To match the future load demand to get uninterrupted power supply, use renewable energy sources increasing day by day. Faults can occur transmission lines, transformers, generators, busbars but nature these faults may change many times when considered. This r...

This paper presents a grid connected photovoltaic system, which acts as both power generator and active power filter (APF), based on Flying Capacitor Multicell (FCM) converter. Increase in the number of output voltage levels, natural self-balancing of flying capacitors and dc link voltage and lower power rating of components are the main futures of FCM converter compared with conventional multi...

This paper presents a grid connected photovoltaic system, which acts as both power generator and active power filter (APF), based on Flying Capacitor Multicell (FCM) converter. Increase in the number of output voltage levels, natural self-balancing of flying capacitors and dc link voltage and lower power rating of components are the main futures of FCM converter compared with conventional multi...

Abstract For the two typical topologies of extra high voltage magnetically controlled shunt reactor (MCSR), this study introduces its specific wiring methods and working principles. It conducts an analysis change characteristics response core magnetic flux under different modes body. Based on PSCAD, structures are used to model body first 500 kV MCSR put into operation in a provincial power gri...