This paper introduces the harmonic can cause harm to the volatge networ,you can make measure to restraint harmonic,The harmonic canleling design are being used to mitigate the effects of harmonics.

• 电压偏离正压波形,会产生谐波电流,对电网产生不利影响,介绍了谐波对电网造成危害,对谐波采取抑制措施,并提出合理的设计方案,说明其应用效果。