High impedance faults (HIFs) present great difficulty of identification and location in distribution networks (DN) due to their characteristics of low current magnitude. Advances in smart grids and distribution automation allow the detection of disturbances that were previously unnoticeable in DN. This work aims to present a new method for detection and location of HIFs from smart meters placed at strategic points in the feeder, using a voltage unbalance based approach. The methodology was evaluated through simulations in MATLAB / Simulink, focusing on the detection of high impedance series faults. The results showed that the algorithm effectively identifies broken conductors, with or without ground faults, located either at the load or source side. Once technical and economic feasibility is proven, these methods can assist energy distribution utilities in restoring the normal operating conditions of the distribution network.

High impedance faults (HIFs) have been a major concern for protecting distribution systems and public safety hazards when involving downed conductors. The deployment of smarter grids brings new technologies for smart monitoring, automation, and protection of distribution networks. This paper presents a new method for a series of HIF detection and location in primary distribution feeders, using voltage unbalance measurements collected from smart meters (SMs) installed at low-voltage end-users. The methodology was tested in MATLAB and Simulink through steady-state simulations of a typical 13.8 kV distribution system, under load unbalance and different fault scenarios. Results show that the proposed method is robust and accurate for the detection of blown fuses and broken conductors, with or without ground faults, located either at the source or the load-side. The ease of implementation in SM design, formulation of parameters, and reliable simulation results show potential real-life applications.

The electrical distribution system is undergoing major changes as distributed generators, power electronic devices and smarter grids applications are inserted in the system networks. Although the changes are beneficial for satisfying the needs of local loads, electrical performance parameters issues may arise due to the impact of the changes in the network. In order to perform studies and verify the impact of new elements in distribution systems, simulation tools are important resources for planning by researchers and engineers. This paper aims a discussion on how linear aggregate loads affects harmonic studies. Simulations are performed using different load models to verify the impact and sensitivity of the system impedance and resultant harmonic voltages. Harmonic sources produced by typical distributed generators are connected into the system in order to analyze the harmonic voltage distortion at different buses regarding the simulated network. The systems were modeled and simulated in an OpenDSS Matlab interface. Results shown that both load model types and composition have a significant impact on the system impedance and parallel resonance damping.

This paper addresses a preliminary research on numerical simulation method of an double-layer shielded and low voltage power cable for electric vehicle powertrain using Finite Element Analysis (FEA) and Simulation Program with Integrated Circuit Emphasis (SPICE) as software tools. Simulating this detailed method through FEA for only one transmission line cell, it was obtained the transmission lines parameters and the magnetic flux density of the cable. Then, its length is extended by using transmission lines theory and the frequency response of the cable was gathered as an evaluation of the current method implemented in SPICE. Thus, those analyses can provide a faster and better overview concerning the prediction of cable's electromagnetic (EM) shielding behavior in order to avoid Electromagnetic Compatibility (EMC) compliance issues in the early -stage development of vehicles.