The Research of Electric Field and Insulation Characteristic for UHV Electric Appliance
|School||Shenyang University of Technology|
|Course||High Voltage and Insulation Technology|
|Keywords||UHV Isolation switch Electrostatic field Transient electric field Fast transient overvoltage|
With China's first 1000 kV UHV AC pilot demonstration project commissioning and commissioning work started , the development of UHV level of the transmission grid , millions of volts level UHV electrical equipment is necessary to research and development . With the rise of voltage levels , put forward higher requirements for UHV electrical insulation properties . The electric field numerical calculation of the structural design of the special high - voltage electrical equipment , as well as to improve its insulating properties , has a vital role . This article on UHV GIS isolating switch gas chamber three-dimensional electric field is analyzed and calculated . Meshing model parameter set self - defined mesh control tools for the complexity of the model structure , application , intelligent split after a series of problems . Numerical analysis based on electric field theory , using the finite element method to calculate the electric field isolation switch gas chamber , the internal electric field intensity distribution and internal insulation component surface electric field intensity distribution curve , by the results of analysis of the electric field strength , and come to the isolation switch gas the position and the electric field intensity of the indoor larger electric field strength values. Finally, the calculation results insulation checked to verify the insulation level of the UHV isolation switch . The fast transient overvoltage (VFTO) . Specific to an over-voltage in GIS , isolation switching division bus capacitor current , with a short rise time and amplitude characteristics , and working gas pressure under the insulator creepage VFTO role under far more dangerous than lightning wave . Thus , in this study VFTO under basin-type insulators along the surface electric field distribution . Transient mathematical model calculated VFTO role , basin-type insulators potential distribution and the distribution of the electric field strength . By comparative analysis of results of the basin-type insulators transient and static electric field , most of the insulation of GIS and its associated equipment designed by the electrostatic field , considering only the lightning impulse with operating under the impact of the electric field characteristics is inaccurate , it should take into account the transient characteristics of nonlinear high-frequency dielectric constant change , inspect the insulation level of the basin-type insulators should calculate the maximum transient electric field criterion . Thus provide a theoretical reference insulator insulation structure design for the basin .