rotection schemes employing the differential relaying principle exhibit certain limitations in applications with power transformers. This is because the detection of a differential current does not clearly distinquish between internal faults and other possible conditions. Among the phenomena most likely to upset the current balance and cause the relay to malfunction are inrush magnetizing curre...

Second harmonic restraint is still commonly used to discriminate fault current and transformer inrush conditions. Such approach, however, has some disadvantages and limitations. Therefore various other criteria signals for power transformer inrush discrimination have been analysed. The paper presents a new multi-criteria stabilization algorithm that employs fuzzy reasoning technique for better ...

Each fuzzy set can be represented by a nested system of ordinary sets—its a-cuts. There is an extensive literature on fuzzy sets devoted to problems of the following kind: is it possible to reduce operations with fuzzy sets to operations with their a-cuts? Is it possible to reduce properties of fuzzy relations to properties of their a-cuts? More generally, can a fuzzy concept be represented by ...

Transformer and feeder load balancing in a distribution system reduces the risk of overloads due to load changes. The possible out of service area following the occurrence of a fault is also reduced. However, keeping in view the life expectancy of the switches, it is desirable that the number of switching operations is kept to a minimum. A new algorithm for load balancing based on fuzzy set dec...

By the representation's theorem it is known that a fuzzy relation R is a preorder if and only if R = inf~ e so If, where -~ is the set of logical states of I~ In this paper it is shown how, in almost all cases, both for the t-norm Min and archimedean t-norms T, it is possible to consider that the fuzzy sets I~ are normalized. Furthermore a partial order between logical states, defined from the ...

Continuous monitoring of Power transformer is very much essential during its operation. Incipient faults inside the tank and winding insulation needs careful attention. Traditional ratio methods and Duval triangle can be employed to diagnose the incipient faults. Many times correct diagnosis due to the borderline problems and the existence of multiple faults may not be possible. Artificial inte...

This project presents reactive power compensation in a distribution power system. DSTATCOM (distribution static compensator) is a reactive power compensator for power quality improvement in a three phase four wire distribution system. A voltage source converter (VSC) based DSTATCOM with a zig-zag transformer is used for the compensation of reactive power for voltage regulation along with load b...

We introduce a simple programming language and define its predicate transformer semantics. We motivate the choice of the constructs for the language by algebraic arguments, showing that the constructs are essentially the basic algebraic operations that are available for predicate transformers, when these are viewed as forming a complete lattice enriched category. We then show that the statement...

The determination of transformer fault categories using soft-computing based techniques has been the subject of much research in the recent past. The development of an adaptive fuzzy classifier which can effectively determine various classes or categories of series and shunt impulse faults in a wide range of power transformers is described. The system employs a self-generating module to automat...