The occurrence of heavy rainstorm can keep the air gap insulation distance of transmission lines

towers and insulator strings short circuited

resulting in rain flash accident and endangering safe operation of power grid. In order to study the breakage performance of the water streams and its influence on the discharge characteristics under rainstorm conditions

the breakage performance of the water streams in rod-plate short air gap is performed by means of simulation combined with test in this paper. The result shows that under different flow velocities the breakage length of water streams decreases with the increase of applied voltage

but the decreasing trend is negatively correlated with flow velocity. The critical length of the water streams increases with the increase of the flow velocity

and decreases with the increase of water conductivity

but the decreasing trend increases accordingly. In addition

the breakage diameter and breakage time of water streams decrease with the increase of applied voltage

and the variation rates of both are positively correlated with the diameter of water streams. It is found by comparing the simulation calculation with the test results that the breakage diameter and length have the same variation trend with rainfall intensity and voltage. The deviation of the data of breakage diameter is about 10%

and the deviation of breakage length is within 15%. The research results can provide theoretical support for the design and insulation selection of transmission line.