Based on the techniques of high gain observer and adaptive estimation, an algorithm is proposed in this paper for sensor fault estimation in nonlinear systems. It is essentially assumed that a high gain observer exists for the fault-free system. A high gain adaptive observer is then designed for sensor fault estimation. The convergence of the algorithm is established under a persistent excitati...

Overhead transmission line is an element of electrical power systems that are most frequently experienced short circuit faults compared to other power system elements. Short circuit faults on overhead transmission line cause a relatively large current and therefore can damage mechanically the electrical equipment connected to the system. The protection system is essentially needed in this situa...

in this paper, design and application of a new digital protective relay based on fuzzy logicand value estimation to a radial power system protection was presented. a novel approach based onvalue estimation was investigated for the proposed fuzzy logic based protective relay. in addition to thetheoretical aspect of fuzzy logic, mathematical definition of value estimation, detection andmeasuremen...

We present a fast, dynamic fault coverage estimation technique for sequential circuits that achieves high degrees of accuracy by signiicantly reducing the number of injected faults and faulty-event evaluations. Speciically, we dynamically reduce injection of two types of faults: (1) hyperactive faults that never get detected, and (2) faults whose effects never propagate to a ip-op or primary ou...

In this paper, some recent advancement made in the field of model based fault identification are elucidated and shown that bond graph modeling is well suited to solve fault detection and isolation problems in automated real time process engineering supervision systems. We present a case study and implement an online fault diagnosis scheme through parameter estimation to a belt conveyor system. ...

This paper presents a novel approach for fault detection and identification in order to estimate voltage sag during a fault. One of the best approaches for voltage sag estimation is instantaneous voltage estimation. The approach uses traditional state estimation where redundant measurements are available. The proposed method is used to estimate voltage sag performance during a fault. At the fau...

Many schemes are reported for shunt fault location estimation, but fault location estimation of series or open conductor faults has not been dealt with so far. The existing numerical relays only detect the open conductor (series) fault and give the indication of the faulty phase(s), but they are unable to locate the series fault. The repair crew needs to patrol the complete line to find the loc...

An Iterative Learning Observer (ILO) updated successively and iteratively by immediate past system output error and ILO input is proposed for a class of time-delay nonlinear systems for the purpose of robust fault diagnosis. The proposed observer can estimate the system state as well as disturbances and actuator faults so that ILO can still track the post-fault system. In addition, the observer...