Research On The Improvement Of Electric Field Of The Composite Insulators End

The composite insulators, which are widely used in the power system, are extended with the purpose of avoiding the pollution flashover effectively. But in the recent years, pollution flashover still took place on a number of composite insulators. The pollution flashovers almost all cause the damage of the grading ring, the hardware at the end, and the shed, sheath around the hardware, making the insulators drop and the lines break, leading to a great number of economic loss.In this paper, the exsiting calculation methods of composite insulator's electric field are summarized and the mathematical model of calculating the composite insulator's electric field is established, on the basis of which the distribution of composite insulator's electric field along the surface under clean and polluted conditions is analysed, and the influence of grading ring on the distribution of composite insulator's electric field and its limitations are also discussed. Based on the ideas that "Extending the edge of the hardware can ameliorate the electric field intensity around the stick", a new platform-type hardware is proposed creatively, with the purpose of producing new composite insulator with low electric field intensity. Using the methods of theoretical calculation, Simulation Calculation using ANSYS and test, under the dry and wet conditions, the electric field intensity at the end of the composite insulators with new hardware and common hardware is calculated, including the maximum electric field intensity around the hardware, the maximum electric field intensity around the first shed and the the maximum electric field intensity on the stick. The influence of platform radius and thickness of the new hardware on the electric field at the end of composite insulator is also analysed. Through the comparison of the influence of common hardware and new hardware on the electric field at the end of composite insulator, proving that the new composite insulator with low electric field intensity can improve the inception voltage of the corona on the hardware at the side of the high-voltage and also decrease its electric field intensity. Using the new composite insulator can eliminate or reduce the pollution flashover. This research has some academic value and applications.