重庆大学电气工程学院
School of Electrical Engineering,Chongqing University
在电力系统中，电力电容器承担着无功补偿、滤波、载波以及高频保护的作用。随着电力系统向着“双高”特征快速发展，施加在电力电容器上的电压信号包含了大量谐波电压，谐波电压加剧了极板上电压电流信号的不均匀分布。电力电容器发热与老化与其有功损耗密切相关，因此在综合考虑金属损耗与介质损耗的基础上，提出电容器在谐波电压下的宽频分布式参数等效模型，推导出电压电流分布特性与损耗解析表达式，并进行计算，分析总结规律：在谐波电压下，流经电容器极板的电流增大，极板金属损耗与介质损耗均大幅提升，呈现不均匀分布，损耗产生热量，影响电容器绝缘和运行状态。
In the power system, power capacitors play the role of reactive power compensation, filtering, carrier wave, and high-frequency protection. With the rapid development of the power system towards the "dual high" characteristic, the voltage signal applied to the power capacitor contains a large amount of harmonic voltage, which exacerbates the uneven distribution of voltage and current signals on the capacitor plate. The heating and aging of power capacitors are closely related to their active power losses. Therefore, considering metal and dielectric losses, a wide-band distributed parameter equivalent model of capacitors under harmonic voltage is proposed. The voltage and current distribution characteristics and loss analytical expressions are derived, and calculations are carried out to analyze and summarize the law: under harmonic voltage, the current flowing through the capacitor plates increases, The metal loss and dielectric loss of the electrode plate have significantly increased, presenting an uneven distribution. The loss generates heat, which affects the insulation and operating status of the capacitor.
