换流站中电容器装置噪声水平计算方法的研究

Study on the Calculation Method of Noise Level for Capacitor Installation at Converter Station

滤波、并联电容器装置的噪声是换流站中噪音来源的主要因素之一,有必要对其计算方法进行研究。文中介绍了电容器振动及噪声产生的机理,即:电极间的电场力将使电容器的外壳振动并最终变为噪声辐射出去;根据电容器在机械力激励作用下其表面的振动响应,计算得到了电容器外壳振动的频响函数以及在电容器流过特定电流时其外壳的振动响应;提出了电容器表面振动速度与其产生的噪声之间的关系,并由此计算了单台电容器在流过含有高次谐波分量的电流时的噪声水平;对一滤波电容器装置的噪声水平进行了计算,结果表明利用文中提出的方法可以有效、方便地计算电容器及电容器装置的噪声水平,为换流站的建设提供参考;文中最后对灵宝换流站中滤波电容器装置的噪声水平进行了测量,并与计算值进行了比较,分析了二者产生差异的原因,验证了文中所提出方法的正确性。

The noise of filter and shunt capacitor installation is one of main noise source at converter station, it is necessary to study its calculation method. The mechanism of capacitor vibration and noise is described, the electric field force between electrodes leads to the vibration of capacitor tank and then the noise is produced and radiates out. According to the vibration response of capacitor tank when the capacitor is excited by an impact force, the frequency response function of capacitor tank can be acquired and then the vibration response of capacitor tank can be calculated when the current with high harmonic components flows through the capacitor. The relationship between the vibration velocity of capacitor surface and its noise is presented, and the noise level of single capacitor is calculated when the current with high harmonic components flows through it. The noise level of a filter capacitor installation is calculated, the results show that the capacitor installation noise level can be predicted effectively and conveniently, and it can be taken as reference for construction of converter station. Finally, the noise level of filter capacitor installation at LingBao convener station is measured and compared with calculation value and the reasons leading to their difference are also analyzed. The comparison between measurement and calculation validates the presented method.