The Research On Arc-Quenching Of Lightning Protection GAP Based On Vertical Air-Blast In A Constrained Space

To address the problem of lightning struck on overhead transmission lines, a kind of air-blast arc-quenching parallel gap lightning protection device (ABAQPGLPD) installed on the overhead transmission lines was developed. Combined with the theory of computational fluid dynamics and finite element analysis and other related disciplines, this paper studied the characteristics of electric arc under the conditions of vertical air-blast in a constrained space, and the arc-quenching process was simulated.This paper analyzes the arc energy balance and the ways of power dissipation, such as conduction, convection and radiation. The conditions and influencing factors of the arc-quenching are also analyzed.The main contents of the paper are as following:Solving the equations of the flow field in the champer by FEM soft ANSYS, obtain characteristics of the airflow, simulate the airflow patterns at different entrance pressure, obtain the pressure distribution contour maps and the velocity field distribution vectors in the champer.At the same time, using the analysis function of coupling field of ANSYS, This paper simulate the interrupted process of arc plasma under the condition of vertical air-blast in a constrained space, obtain the changes of temperature field and velocity field. And then we discussed the arc quenching process. The simulation shows that the arc can be cut off instantly by the high-speed airflow.This paper presents an electric arc model that can approximately represent both static and dynamic characteristics of an arc burning between the lightning protection gap controlled by a power circuit. The proposed model was developed from the combination and modification of the classical Cassie and Mayr equations. The model equations have been expressed in a form suitable for incorporation into circuit simulators employing the nodal-analysis method of equation solving. Based on the model equation, a PSCAD/EMTDC-based arc model is constructed. Based on the constructed arc model, the interruption processed of arc by vertical air-blast in a constrained space is simulated in chapter5. Simulated and experimental results appear to be in good agreement.