Electrical Faults in Power Systems

1. Introduction

Power system analysis usually involves the calculation of the different electrical parameters (voltages, currents, power…) under specified conditions. When the computation concerns the normal operating mode; the calculated parameters are called the nominal (or rating) values of the system, whereas, if it considers the abnormal circumstances that can effect on the normal functioning of any electrical equipment, the calculation must be regarded as fault analysis (FA).

FA aims to identify and classify faults according to:

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  Nature: Current, voltage, frequency…,

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  Magnitude: Over or under the magnitude of the nominal value;

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  Synchronization: Phase shift, time;

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  Duration: Transient or steady state mode;

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  Progression in Time: Oscillatory, impulsive, constant….;

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  Emplacement: Internal or external;

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  Exposition Manner: Direct, indirect, induced…;

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  Tolerance: Tolerable fault, dangerous fault.

In this chapter, we try to give the most comprehensive approach allowing to distinguish efficiently among the different electrical faults and remove some ambiguities causing confusions and difficulties for the accurate classification of faults, while indicating the definition limits of each fault.

Once the faults terminologies, presented here, are well understood and properly assessed; they can be used efficiently to develop competitive algorithms dedicated to fault detection, classification, isolation and diagnostics.

2. The Main Electrical Faults