When the frequencies of the joined ac systems are different, there will be not only characteristicharmonics and uncharacteristic harmonics but also interharmonics.
在连接不同频率的交流网络时，它不仅存在通常HVDC系统的特征谐波、非特征谐波，还存在着间谐波。
2
A mass of power electronics equipments with nonlinear characteristic are the main source of harmonics in low-voltage power system.
低压电力系统中大量具有非线性特性的电力电子设备是产生谐波的主要原因。
3
Due to different wavelet threshold fit for different characteristic of signal, various wavelet de-noise threshold was used to decline the harmonics of signal and the best threshold was chosen.