A new proposed dynamic arc model for flashover performance of a non-uniform polluted insulator string under HVAC stress

• The paper investigates flashover of non-uniform polluted insulators with HVAC stress.
• The present paper introduces a new proposed dynamic arc model to simulate flashover.
• Experimental work is done to validate the simulation by proposed dynamic arc model.
• The results reveal that as pollution severity increases, flashover voltage decreases.
• The Comparison of proposed model results with Rizk model results is satisfactory.

This paper presents a new proposed dynamic arc model of a non-uniform polluted insulator under HVAC stress taking into account the dynamic arc characteristics. The model is based on a hybrid formulation of Obenaus model and the mathematical development of arc equations by Rizk combined with the dynamic equations of the change in arc resistance by Mayr. The model adopts the criterion of Hampton for arc propagation and the model is simulated using MATLAB Simulink. The model can calculate the instantaneous changes in arc current, arc length, arc resistance, and pollution level on insulator string at which the flashover occurs at certain voltage. Practical insulator geometries have been studied to demonstrate the model with non-uniform pollution in different positions and levels of pollution. The validity of the model is verified by comparing the simulation results with the experimental results and previous works.