Dimensionamento de gerador de impulso de corrente portátil para medição de impedância impulsiva de aterramento

Abstract

Atmospheric discharges pose a challenge to power transmission and distribution systems, potentially causing equipment damage and service interruptions. Electrical grounding is essential for dissipating these currents, but its effectiveness depends on proper design and evaluation. Grounding resistance, commonly measured with earth resistance meters, does not accurately reflect grounding behavior under impulsive and high-frequency phenomena, such as lightning strikes. Therefore, characterizing the impulsive response of grounding systems involves applying impulsive currents and calculating the resulting impedance. Current Impulse Generators (ICG) are widely used for this purpose, but their cost, weight, and size limit field applications. This study proposes a portable ICG capable of generating exponential impulse currents (EIC) with an 8/20 𝜇s waveform and amplitudes up to 6 A, suitable for horizontal electrode or counterpoise grounding systems ranging from 15 to 60 meters. Simulations were conducted using LTspice and MATLAB to define optimal circuit parameters, assess performance, and suggest commercial components. The results indicate that the designed ICG meets the technical requirements for reliable impulsive impedance measurements, with twenty different component configurations presented for applying EIC in grounding systems. Thus, this study introduces a compact, cost-effective alternative for evaluating power transmission line grounding systems