Dynamic Thermal Rating Assessment Method of Oil-immersed Power Transformers Based on Typical Load Profiles
The development direction of asset lean management is to evaluate the power transformer's dynamic thermal rating and improve the transformer's utilization rate to ensure equipment safety.In this paper,a method for evaluating the dynamic thermal rating of the transformer is proposed to determine the dynamic load curve under different working conditions,which is combined with the operating conditions of the transformer.It comprehensively considers the constraints of hot spot temperature,top oil temperature,losses of life,bushing and on-load tap changer maximum allowable current,and so on.Meanwhile,the most sensitive constraints limiting the load are given.Firstly,by analyzing the thermal parameters of the dynamic temperature rise model,the thermal parameters and the temperature rise model are optimized according to the temperature data measured by the winding optical fiber.The maximum error of the hot spot temperature estimation does not exceed 3 K,which means the accuracy of the hot spot temperature estimation model is improved.Secondly,based on the historical data,the typical load curve and the corresponding ambient temperature curve are extracted as the input ambient temperature curve are extracted as the input parameters of the evaluation model.Finally,several application examples for transformers in different scenarios are studied to analyze the limiting factors.The results show that the maximum allowable bushing and on-load tap changer currents may become the main factors limiting the dynamic load capacity of the transformer,and the load capacity can be improved by more than 28％in different scenarios compared to the rated operating conditions,which has a large load potential.
万方数据
维普
