Enhancement of earth grid electrode performance by adding parallel-insulated conductor

الملخص

The high-frequency performance of vertical earth rods is important for designing earthing systems and lightning protection systems, hence they have proved their advantages in order to protect electrical apparatus during severe lightning strikes, and an easy path for electrical current to ground was successfully achieved. The current distribution tests in the insulated and bare sections of the 88m horizontal electrode system were carried out at the Cardiff University outdoor earthing test facility at Llanrumney fields. Several test frequencies were used ranging from 52Hz to 100 kHz using the impedance measurement system (IMS) instrument, Impulse tests were carried out on the grid 5m×5m, 25 mesh with/without bonding to the 4.8m rod were measured with the Modular Impulse Generator (MIG) for a range of impulse rise times (~1.44-6µs). Examples of the transient voltage response (earth potential rise). It was concluded that the voltage distribution along the conductor at 52Hz is flat and the current flowing from the insulated conductor to the buried bare conductor. This paper would also illustrates experimental results of a grid with and without high frequency electrode enhanced with proposed insulated above ground conductor.

The aim of this work is to improve impulse response performance by reducing the earth potential rise of the earth grid.

This experimental work has proved that using insulated conductors in parallel with earth grid has significantly enhanced the impulse response; little reduction in voltage at slow rise time was noticed. However, the grid impedance effect has also been demonstrated at fast rise time.