Prediction of voltage sag in the transmission system of Vietnam, A case study

Abstract

In this paper, a novel effort for prediction of voltage sag in the entire transmission system of Vietnam is presented. As the Vietnamese electricity industry moves toward the electricity market, prediction will help utilities have early assessment of power quality in transmission system. The proposed prediction approach uses a fault position method in which the fault distribution in the transmission system is created based on an actual fault occurrence in the entire 220kV and 500kV transmission system throughout Vietnam that took place in 2008. The research also makes use of the SARFI CURVE with ITIC and SEMI curve, which takes into account of the actual fault clearing time of protective devices used in transmission system in Vietnam. By using SARFI CURVE , a better assessment of voltage sag performance is obtained in the transmission system with regard to load's voltage tolerance.

Effects of the penetration of inverter‐based generators on voltage sags in HV networks: Analysis of the Sardinian network

“…Regarding HV networks, several works deal with voltage sag analysis and prediction 9‐21 . These analyses are usually carried out using a stochastic approach.…”

“…The work in Reference 15 presents the equations for the calculation of the sag magnitudes produced by both balanced and unbalanced faults, using the IEEE 30‐bus test system for computation. Conversely, a real power system (the actual 500‐220 kV transmission system of Vietnam) is studied in Reference 16. Numerical applications refer to real networks also in Reference 17, which proposes some indices of robustness to synthesize the bus performance.…”

Impact of Distributed Generation on the Voltage Sag Performance of Transmission Systems

“…It is possible to obtain the probabilistic characteristics of the sags that are needed to measure their severity by proper statistical indexes [6,21,22]. This allows derivation of the expected performance of a node or of the entire system in terms of e.g., the number of sags per year and the average amplitude of the sags.…”