Development of Digital Twin Plat-form for UHV Converter Transformer Bushing Based on Material Simulation and Optical Detection

UHV converter transformer bushing digital twin platform includes the typical power equipment such as valve side bushing and support structure of the UHV converter transformer. For its typical power equipment, 3D modeling is generally carried out through digital modeling, but the surface temperature and electric field strength values of the equipment can be sensed through the temperature sensors. This process includes material performance research and theoretical formula research, the material research mainly includes the relationship between the real part of the dielectric constant and temperature variation. At the same time, quantitatively describe the 3D relationship between the tangent value of the loss angle of the bushing core material of the ultra-high voltage converter transformer and the temperature, and use the neural network function RBF neural network for quantitative fitting. The fitting results indicate that the error is close to 0 in most regions, and only exists near the low-frequency range of 100Hz. The above errors are caused by the edge effect of the numerical nonlinear fitting. Within the testing range of the 10
^-4
~ 10
⁴
Hz, the dielectric response characteristics of pure epoxy and epoxy impregnated paper can usually be described using the modified Cole-Cole model that includes single or two relaxation processes. On the other hand, online monitoring of SF6 gas inside the casing is carried out, and the time-sharing multiplexing is used to convert the electrical signals carrying spectral information after photoelectric conversion into current and voltage, and filter and amplify them. The monitoring results indicate that when a temperature sensor is installed on the surface of the bushing, the bushing generates temperature heating under current carrying conditions. After the temperature heating, the temperature value gradually increases over time and tends to stabilize. After value stabilizes, it can reach 100 °C, and bushing oil temperature is about 80°C. The research results of article have good theoretical and engineering application value for the online monitoring of the operating status and parameters of the ultra-high voltage converter bushing.