求助 电动工具谐波问题

tuyunliang

广东安规检测
有限公司提供：

小型摆管淋雨试验机

IPX5X6X7喷水试验机

1000L恒温恒湿箱

各种试验指现货

可程式恒温恒湿试验箱

水平垂直燃烧机

自动卷线器试验机

耐划痕试验机

各种灯头量规现货

灼热丝试验机现货

GB1002插头量规

IPX1-X7淋雨现货

IEC61347/UL935镇流器热试验箱

灯具防风罩

IK冲击试验机

UL498插头插座量规

VDE0620插头插座量规

稳定性试验台

家电温升测试角

针焰试验机现货

热电偶焊机现货

家电125mm试验指

E12灯头量规

无绳壶无绳电熨斗插拔寿命试验机

IEC60335试验指甲

小弟有一带调速的电锤在EMC测试中谐波电流超了，调速器厂家说没有办法，我自己也不知从何下手整改，求助各位前辈能指点一二。
2次和4次谐波电流超，其余的都是可以的，
产品接了1个0.22+2*2200的三角电容和1个20-30uH的电感，电机参数是0.53/16+0.65/130，调速器据说是全波整流的。

tuyunliang

2次诣波值1.696，超4.5%
4次谐波值0.822，超27.5%

kamleung

Your product is portable tool and classified as Class B in EN61000-3-2. The corresponding limits should be 1.5 x Table 1 (Class A limit). Hence, it is rarely failed in the harmonic tests because the symmetric control is normally used.
; W9 t3 g; u: F" K; L
( x0 V7 m/ a8 P5 Q9 w6 s' RIn view of your data, your speed control is most likely using the TRIAC to change the Fire Angle.  And, the motor is fairly high power. Otherwise, the 2nd and 4th harmonics should not be as high as yours. If that is the case, your supplier is correct that the harmonic problems are difficult to be solved in the circuit design.

As my motor-driven product is usually of low power type, I also not sure whether my suggestion is workable or not. Perhaps, you may consider
     - changing your motor to be a less power one, or
     - change the control method from Fire-angle control to PWM control
! f0 ]( x) S2 }6 ?+ c9 p/ A
$ y' J* Y, ?% i5 JHopefully, it may help.