Design Of The Key Insulation Component For An Electromagnetic Pulse (EMP) Simulator

The trend of higher electric stress and faster rise-time Electromagnetic Pulse (EMP) simulator stimulates the development of more advanced pulse generator. The size of the insulator in the key component of a pulse generator determines the inductance value in the circuit generating the pulse. Thus the design of a small size insulator with high voltage tolerance is one of the key techniques to depress the rise-time and amplitude.In this paper a MV-level basin-shaped insulator made of fiberglass reinforced composite material is investigated, which is needed in a MV-level pulse generator for EMP simulator. The study of the composite material reveals that the tensile and compressive strength is higher along the fiber orientation, and it has obvious linear regions, which means in a certain rage of load the material can be considered as linear material with a constant elastic modulus. The damage failure process of 0°extended layer in the material begin with a relative slip of the glassfiber and the resins, when the fiber endures the force. The force keeps increasing before massive fracture of fibers appears. In the end, most of the fibers separated from the base and causes unevenly disputed stress on the fibers, making the fibers pulled out or fractured into fiber bundles. The damage failure process of 45°extended layer in the material is mainly occurred when the damage of the binding surface of the fiber and the base is made. The fracture is significant with a direction along the fiber orientation. The rubber content should be controlled around 22% in order to improve the material integral strength. Surface flashover experiments show that under a 50 ns rise-time, 300ns FWHM (full width at half maximum) pulse voltage, an electric field intensity of 11kV/cm in three joint points, a 1.92 non-uniform coefficient and a 110kV/cm surface electric field intensity, the material did not flashoverOn the basis of research in fiberglass reinforced composite material, the design of a MV-level basin-shaped insulator is investigate. Epoxy and alkali-free fiberglass winding technique is applied for the production of the insulator. The maximum stress occurs around the hole in the bottom of the basin-shaped insulator, with a magnitude of 47.3Mpa which is lower than the test result of 450 extended layer fiberglass reinforced material (tensile strength 145.17Mpa,shear strength 72.58Mpa). The electric field intensity in three joint points is 11kV/cm under 2.5MV voltage, and the surface electric field intensity is 60kV/cm. all of these fulfill the design requirements. The designed insulator did not flashover in the gas environment of SF6 and dry air mixture (the volume ratio of SF6 is 20%). Further experiment with higher voltage should be tested in pure SF6 environment. The study of this paper has reference value in designing special shaped insulators under high mechanical strength and high voltage.