数据驱动的台区配电变压器接头阻抗计算与温升预警方法电变压器区配电变警方法

Data-driven Method for Impedance Calculation and Temperature Rise Warning of Joint of Distribution Transformer

为解决配电网中部分配电变压器在长期运行后出现的导线接头老化,局部温升严重等安全隐患发现不及时的问题,建立了针对台区配电变压器三相四线制接触阻抗高准确性计算模型,形成了数据驱动的配电变压器潜在安全隐患温升预警方法。利用三相四线制台区变压器的等值电路模型,构建了计算接触阻抗的等价方程组。因方程组变量数大于方程组数目,特将不可解方程组模型转化为求最小值的等效优化模型,并运用BFGS优化算法对模型进行优化迭代求解。利用最大负载电流下的长期发热模型,建立了接触阻抗与温度的等价关系,形成了接触阻抗的分级预警体系。利用江西电网两个实际台区现场运行数据,验证了所提出方法的有效性。

In order to solve such safety hazard problem as aging of wire joint and serious partial temperature rise of partial distribution transformer in the distribution grid,which is occurred after long term operation and and is not found in time,a high-accuracy calculation model for the contact impedance of the three-phase four-wire system of distribution transformers is set up,and a data-driven early warning method for potential safety hazards of distribution transformers has been formed.The equivalent circuit model of the transformer in the three-phase four-wire system is used to construct the equivalent equation set for calculating the contact resistance.Since the number of variables of the equation set are greater than the number of equation set,the equation set model is specially converted into an optimized model for seeking the minimum value and the BFGS optimization algorithm is used to optimize the model iteratively.The long-term heating model under the maximum load current is used to set up the equivalent relationship between contact resistance and temperature,forming a hierarchical warning system of contact resistance.The effectiveness of the proposed method is verified by the field operating data of two actual stations in Jiangxi power grid of China.