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...

Abstract In today’s society, people can’t live without electricity. During the operation of power equipment, there may be various potential safety risks. particular, partial discharge is easy to occur at terminal. If can not deal with problem in time, equipment continue live.Setting cause security, so electric industry staff attaches great importance local monitoring problem.Ultrasonic technolo...

− In the last years the increased interest about power quality, forced international working groups to define new standards for testing and measurement techniques. In this paper a pc-based power quality instrument is proposed, according to IEC 61000-4-7 and standard IEC 61000-4-30. It is a low-cost and easily reconfigurable instrument able to measure harmonics, interharmonics and amplitude dist...

Current and voltage transformers influence the criterion values measurement particularly during disturbances in the system. Certain construction limitations of instrument transformers may in some cases cause maloperation or substantial delay in tripping of the protective relays. Current transformer saturation and discharging of the capacitive voltage transformer’s internal energy during short c...

The knowledge of DC time constants in fault currents at system nodes is important to design the protection system and validate the calculation models for power system simulations. In this paper, we present methods to estimate Thévenin’s impedance and DC time constants in fault currents with application to disturbance records. Additionally, a comparison between both parameters is shown. We demon...

A method for testing electronic instrument transformers is described, including electronic voltage and current transformers (EVTs, ECTs) with both analog and digital outputs. A testing device prototype is developed. It is based on digital signal processing of the signals that are measured at the secondary outputs of the tested transformer and the reference transformer when the same excitation 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...