Power System Protection Studies Research Articles

Functional Mock-Up Interface-Based Approach for Parallel and Multistep Simulation of Electromagnetic Transients

This paper presents a new simulation approach based on the functional mock-up interface standard for parallel and multistep simulation of electromagnetic transients in power grids with computationally expensive control systems. The control systems are represented by slave subsystems, which are decoupled in memory from the power network and encapsulated in functional mock-up units. The simulation modes are either asynchronous or synchronous. In the asynchronous mode, the subsystems are simulated in parallel, whereas in the synchronous mode, the simulation of each subsystem is executed in a sequential multistep environment. Considerable computation time gains in both modes have been observed in power system protection studies on large-scale networks with accuracy properly maintained.

Current Transformer Model

This paper presents a current-transformer (CT) model that is useful for low-frequency applications. To describe the iron-core magnetic behavior, a hysteresis model is proposed, which is able to generate minor asymmetric loops and remanent flux. The effects of classic eddy current losses and anomalous losses are represented by linear and nonlinear resistors, respectively. The obtained results are compared with those calculated by the Preisach's model and measured in the laboratory. This model may be applied in power system protection studies, as it is the case of numeric correction of distorted secondary currents in current transformers (CTs)

A new current transformer model

This paper presents a current transformer model that is useful on low frequency applications. To describe the iron core magnetic behaviour of the iron core, a hysteresis model is proposed, which is able to generate minor asymmetric loops and remanent flux. The effects of classic eddy current losses and anomalous losses are represented by linear and nonlinear resistors, respectively. The obtained results are compared with those calculated by Preisach's model and measured in laboratory. This model may be applied in power system protection studies, as it is the case of numeric correction of distorted secondary currents in current transformers (CT's).

An inductance on the Marx generator tail branch-new technique for high efficiency laboratory reproduction of short time to half value lightning impulses

A technique is presented for the generation of short-tailed lightning impulses with an acceptable degree of efficiency for use in power system protection studies. The method consists in connecting an in-air inductance in series with the tail resistance in one of the standard configurations of the Marx circuit. The validity of the solution has been ascertained experimentally, and a criterion is provided for the analytical determination of the most suitable value of this parameter.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>