# Smart technique for calculating fault current model parameters using short circuit current measurements

## TL;DR

This paper introduces a new method for accurately calculating fault current model parameters using short-circuit current measurements to improve power system protection and automation.

## Contribution

A novel strategy is proposed for estimating fault parameters using short-circuit current data with precise mathematical formulas.

## Key findings

- The method achieves high feasibility, reliability, and accuracy in estimating fault current parameters.
- The algorithm is robust to changes in system parameters and performs well under various fault and operational conditions.
- The approach enables efficient implementation of multiple power system functions using accurate fault current model parameters.

## Abstract

Precise evaluation of fault current model parameters is an important issue in protection and automation systems. These parameters play a crucial role in selecting protective relay settings, detecting, and compensating saturated CT waveforms, calculating AC and DC components, estimating the sub-transient and transient time periods for the short-circuit current, determining fault locations, and controlling a fault interruption to avoid very fast transients that arise from switching. A new strategy for calculating the fault parameters using short-circuit current model is presented. The short-circuit current data is used to estimate fault inception angle, decay time constant, power system angle and maximum symmetrical AC fault current. The difference concept can be utilized to obtain precise mathematical formulas for evaluating the parameters of the fault current model. This is for efficient implementation of multiple functions that include digital protective relay, fault locator, digital filter, CT saturation detector and compensator. The strategy can be applied offline or in real-time. To verify the developed methodology, comprehensive numerical studies on a power system with real parameters data are presented. The power system is simulated using the Alternative Transient Program (ATP) tool. The algorithm is processed using MATLAB© software application. It is examined under variable operating and fault conditions for the system. The quantitative findings indicate that the method has high feasibility, and can achieve reliability, accuracy, and speed in estimating fault current parameters. The results also demonstrate the effectiveness of the proposed algorithm, as well as its robustness with respect to changes in system parameters. Its performance is sustainable as the data window moves, and it is immune to different fault and operational conditions. A key highlight of the proposed approach is the ability to perform many tasks of computer applications in power systems using the accurate calculated parameters for the fault current model.