Grounding System Modeling and Evaluation Using Integrated Circuit Based Fast Relaxed Vector Fitting Approach, Considering Soil Ionization

Abstract

Since high voltage transmission line towers or wind turbines structures are installed in high-altitude areas, it is essential to achieve a high overvoltage protection system against direct and indirect lightning strikes collisions. The lightning current must be discharged quickly into the protective earth, to prevent the dangerous over-voltages formation and define a reference voltage node. This paper presents a novel model to assess the behavior of the grounding system, based on Pocklington integral equations under lightning magnetic fields and variations in soil ionization, in which an explicit circuit-based vector fitting RLC admittance branches are proposed. The frequency-dependent behavior of grounding system frequency response and soil ionization effect is modeled in time domain, straightly to implement into the electro-magnetic transient program (EMTP). The model verification contains horizontal, vertical, and their combinations of grounding grids to represent the complete investigations under lightning strikes. The harmonic impedance mathematical formulations and principles are derived based on a rational function, that could be applicable on ground potential rise (GPR) investigation.

Providing a Control System for Charging Electric Vehicles Using ANFIS

“…In [35], a new modifed optimal algorithm is presented for setting the scale factors and membership functions of a fuzzy-type 2-PI controller by efectively reducing the frequency deviation of the microgrid system against load disturbances. In [36], a main frequency control through a V2G system is introduced in an industrial microgrid, which includes the coordination of the charging station operator and EV operator. In [37], the regional share load frequency control system by plug-in vehicles (PEVs) tries to adjust the frequency in diferent load disturbances.…”

Study on Structural Parameters and Analysis Method of Soil Successive Impulse Discharge Channel

“…Its discharge characteristics directly affect the lightning strike performance of grounding devices [6][7][8]. Strong ionization occurs when lightning injects the soil [9][10][11], and a centralized discharge channel is generated near the grounding electrode instead of uniform dispersion in all directions [6,7]. The development of the soil discharge directly determines the ground potential rise and the influence on the pipelines in the ground.…”