In the present paper simulations of the lightning overvoltages propagation phenomenon in a typical 420 kV SF6 GIS substations are presented. A new overvoltage mitigating passive device in a form of a high-voltage L-C filter is proposed. A process of its development and research is explained along with a simulation results. As demonstrated, the proposed device can be used in HV networks as an al...

With increased electrical energy demands projected in the future, development of a hybrid solar photovoltaic (PV)–battery storage system is considered good option. However, since such systems are normally installed outdoors and open areas, they vulnerable to lightning strikes may suffer from malfunctions or significant damage sensitive components, which result major breakdown loss revenue due e...

Objective: The present study aims atinvestigating the behavior of realized volatility for high-frequency data of Tehran Stock Index from April28th, 2012 to August 8th, 2018. Methods: Three different types of HAR models including of HAR-RV-CJ, HAR-RV and HAR-RVJ were used to analyze the Realized Volatility. Results: The obtained results of three diverse models revealed that the estimated Reali...

Happening of Ferroresonance phenomenon is one of the reasons of consuming and ruining transformers, so recognition of Ferroresonance phenomenon has a special importance. A novel method for classification of Ferroresonance presented in this paper. Using this method Ferroresonance can be discriminate from other transients such as capacitor switching, load switching, transformer switching. Wavelet...

This paper studies the issues of apparent fault loop impedance seen by distance relays protecting a series compensated line with Series Capacitors (SCs) and their Metal-Oxide Varistors (MOVs) installed in the middle of the line. In this paper, SCs&MOVs schemes are equivalented for the fundamental frequency and taken into account in the measurement of the fault loop impedance. Two different appr...

This paper presents a new method for power systems performance optimization using Electromagnetic Transients Simulation. In this method, an emtp-type program (PSCAD/EMTDC) becomes the inner objective function calculation loop of a non-linear optimization program. The procedure is conducted in a Graphical Environment and with the use of specially designed blocks, allows for the selection of any ...