Local Atmospheric Electric Circuit Model Using Electrostatic Pickups on a 375kV Transmission Line

HIGHLIGHTS

• Local Atmospheric Electrical Circuit – LAEC with line transmission

• The waveform in atmospheric coupling (transmission line - LT) is out of phase by 10.34.

• A voltage drop difference of 0.27% is observed in relation to the atmospheric coupling.

• Signal with peaks at 100kV induced approximately 0.66% of the LT voltage (375kV).

Abstract:

The global atmospheric electric circuit is based on a model of electrical connection between the earth and the ionosphere (waveguide), capable of representing the flow of electric current in this waveguide. In the proposed model, a storm acts as a generator, allowing the ionosphere to maintain its highest electrical potential (approximately 300kV) in relation to Earth. When a storm forms, the bottom of the cloud becomes negatively charged. This study is focused on modeling this specific part of the global atmospheric electric circuit, which is renamed local atmospheric electric circuit. In the methodology, we use an RLC circuit to calculate the effects of electrified clouds in a 375kV transmission line considering an electrical coupling between them (an RLC circuit is an electrical circuit consisting of a resistor (R), an inductor (L), and to capacitor (C). The mathematical formulation was developed using transmission line theory considering a connection with the top of the storm cloud. Then, a model simulation using GNU Octave was performed, and the results demonstrated how this coupling affects voltage drop and phase shift in a 375kV transmission line. Thus, a local atmospheric electric circuit model, considering the particularities of the environment immersed in a real transmission line model, configures an important model in the perspective of project management of electric energy transmission networks.

Keywords:
electric atmospheric circuit; lightning; transmission lines; thunderstorm; differential equations