In this paper, a hybrid approach for effective diagnosis of power transformers is proposed. the proposed method, extended Kalman filter used estimation three-phase currents in primary windings transformer. Three residual signals are defined as differences between measured and estimated currents. When transformer healthy, EKF perfectly estimates hence, nearly zero. However, when faulty, cannot s...

Different types of fault current limiters (FCLs) have been developed and designed based on non-superconducting DC reactors (NSDRs). This paper proposes a controllable dual-bridge FCL (CDBFCL) the NSDR for use in an AC-type micro-grid. It includes two series shunt bridge circuits. The is diode semiconductor switches coupled with line via transformer. thyristor parallel line. provides variable vo...

This paper proposes a novel combined device for fault current limiting and dynamic voltage restoring. It consists of a diode bridge superconducting fault current limiter and a dynamic voltage restorer, which both connected together via a common dc link. Interline FCL-DVR system is interlined between two different feeders that connected to a point of common coupling (PCC) in distribution network...

In this paper, according to the lack of relevant studies based on reactive power compensation, the control method related to this subject has been investigated and applied to the Parallel Hybrid Active Power Filter (P-HAPF). Firstly, the dq base control algorithm is applied for harmonic compensation. Then, the reactive power compensation control which is supplied by active filter of hybrid acti...

The linear customer loads are now being dominated by sensitive and sophisticated non-linear customer loads with the growth in the power electronics and control system industries. This have a catastrophic impact on a power system and equipment: increasing harmonics “pollution”. In this paper the modelling of power electronics loads used in domestic and small scale industrial distribution systems...

This paper presents a novel power transformer differential protection scheme by using combined Wavelet Transform and Artificial Neural Network which provide the means to enhance the classical protection principles and facilitate faster, more secure and dependable differential protection for power transformer. Wavelet transform is used to extract the feature from transient signal and the neural ...

A hybrid filter constructed of a shunt active filter and distributed passive filters used for power quality improvement in PV power generating systems is presented. The distribution system consists of a photovoltaic power generation system and several dynamic nonlinear loads. The power quality problems of dispersed generation low voltage systems are introduced and the necessity of using hybrid ...