环境温度及施加电压对自愈式电力电容器温升和温度场分布的影响

自愈式电容器具有无油、低噪声和体积小等优点,尤其适合于城市和清洁能源应用场合。在Fluent 15.0中建立并求解了自愈式电力电容器在400 V交流电压下,环境温度为35℃时的温度场仿真模型。着重分析了外壳和芯子的温度分布,在此基础上分析了环境温度在-25~55℃和承受电压在0.9~1.3倍范围内二者对电容器温度场分布和温升的影响。计算结果表明:不同情况下外壳最高温度均在大侧面,大侧面温度均高于小侧面。随着环境温度的升高电容器最大温升显著减少,随着承受电压值的增加电容器最大温升成快于线性而慢于二次方的速度增大。2种变化范围内电容器最大温升分别在6.86~11.00℃和5.84~10.58℃范围内变化。研究为电容器的运行维护提供了参考。

Influence of Ambient Temperature and Applied Voltage on the Temperature Rise and Temperature Distribution of Self-healing Power Capacitor

The paramount advantages of the self-healing capacitor are oil-free, low noise level and high storage energy density. It is particularly well suited to apply in urban distribution network and clean energy storage. The temperature filed calculation model of a self-healing power capacitor subjected to an AC voltage of 400 V and at a temperature of 35 °C is formulated in Fluent 15.0. The temperature distribution of capacitor shell and core are obtained and systematically investigated. Based on the model, the influences of ambient temperature (ranging -25 °C from to 55 °C) and applied voltage (ranging from 0.9 to 1.3 times of rated voltage) on temperature rise are investigated. The results reveal that: the hottest spot of the shell locates on the large side surface. The temperature of the large surface is higher than that of small side surface. The capacitor (core) temperature rise significantly decreases with increasing in ambient temperature. The rate of change in the temperature rise is faster than that of the applied voltage and slower than square of the applied voltage. The maximum temperature rises in the capacitor ranges from 6.86 °C to 11.00 °C and from 5.84 °C to 10.58 °C respectively. The above results can be taken as a reference to self-healing power capacitor operation and maintenance.