特高压直流输电线路合成电场的天气影响因素及预测模型

特高压直流输电线路电离周围空气产生的离子和线路电场叠加形成合成电场，并在环境因素的作用下使得地面的合成场强发生变化。研究了天气因素对地面合成场强的影响，并提出了基于天气因素的电场预测模型。利用高压直流电场测量装置测量地面合成电场值及环境监测系统所测的天气参数，分析了风速、湿度、气压、温度、PM₁₀、PM_2.5、PM_1.0与场强的相关性。利用基于树形结构Parzen估计器(tree-structured Parzen estimator, TPE)优化的CatBoost建立地面场强在天气因素下的预测模型，并基于所测数据进行模型的训练和预测。结果表明：天气因素对场强的影响权重由高到低为湿度、风速、气压、温度、PM_1.0、PM_2.5、PM₁₀。通过特征排序选取前5个特征和所有特征预测所得到的均方根误差分别为0.83 kV/m和0.85 kV/m,实现了相对准确的预测。研究结果可为特高压直流输电工程环境评估提供有用的合成电场分析方法。

Weather factors and prediction model of synthetic electric field of UHV DC transmission line

The ions generated by the ionized air of the UHV DC transmission line and the line electric field were superimposed to form a synthetic electric field and make the synthetic field intensity of the ground change under the action of environmental factors. The paper investigated the influence of weather factors on the synthetic field intensity on the ground and proposed a prediction model for the electric field based on weather factors. The correlation between wind speed, humidity, air pressure, temperature, PM10, PM2.5, PM1.0 and field strength was analyzed by measuring the synthetic electric field values on the ground and weather parameters measured by the environmental monitoring system used a high-voltage DC electric field measurement device. The prediction model of ground field strength under weather factors was established using CatBoost based on TPE optimization, and the model was trained and predicted based on the measured data. The results show that the influence weights of weather factors on field strength are humidity, wind speed, barometric pressure, temperature, PM1.0, PM2.5 and PM10 from highest to lowest. The root mean square error obtains by selecting the first five features and all features predictions are 0.83 kV/m and 0.85 kV/m, respectively, achieves a relatively accurate prediction. The results of the study can provide a useful synthetic electric field analysis method for environmental assessment of UHV DC transmission projects.