Abstract A used oil sample of KTPJO 10/27.5/023 power transformers which are on the railway was selected and cleaned by means electric field. This process carried out using a device assembled basis special scheme. Unrefined refined samples were tested for electrical strength, i.e. breakdown voltage, AID-70m HUAZHENG (HZJQ-X1 Transformer Oil BDV Tester) dielectric testers. The results compared a...

On-line monitoring of electric power transformers can provide a clear indication of their status and ageing behavior. This paper proposes neural modeling and the local statistical approach to fault diagnosis for the detection of incipient faults in power transformers. The method can detect transformer failures at their early stages and consequently can deter critical conditions for the power gr...

Accurate simulation of a power grid requires use of detailed power equipment models in order to reflect maximum of complex dynamics occurs in the grid. Conventional approaches are not always sufficient to fulfill necessity of meticulous description of processes in power devices. Existence of physical difference even between devices of exactly the same type pulls the accuracy of the whole grid s...

This investigation develops a revisable method for estimating the estimate value of equivalent 10 Hz voltage flicker (DV10) of a DC Electric Arc Furnace (EAF). This study also discusses three 161kV DC EAFs by field measurement, with those results indicating that the estimated DV10 value is significantly smaller than the survey value. The key point is that the conventional means of estimating DV...

Partial discharge (PD) is the main cause of electric equipment degradation. PD location can provide the scientific direction and analysis for equipment condition monitoring. The phased-ultrasonic receiving-planar array transducer for PD location in transformer is studied in this paper. The operation environment and material properties of transducer are analyzed. The center frequency of transduc...

A platform implemented with Digital Signal Controllers (DSCs) developed for real time studies of the dynamic behavior of the air-gapped current transformers (CTs) used in power grid protection and measurement systems is presented. The implemented algorithms simulate the fault current in an electric power system as well as the transient response of the current transformer. It is also presented a...

This paper presents the practical implementation of Phase-Shifting Transformer (PST) model into an Optimal Power Flow (OPF) problem by using the Matlab optimization toolbox. The complexity degree related to the proposed implementation is equivalent to that required by commercial optimization packages for solving optimization models, but with the advantage that Matlab is commonly the available s...