设计滤波器还应注意以下两点
在设计滤波器时,首先应满足各种负载水平下对谐波限制的技术要求,然后在次前提下,使滤波器在经济上最为合理。除以上经济分析外,设计滤波器还应注意以下两点:
In the design of the filter, the technical requirements of harmonic restraint at various load levels should be satisfied first, and then the filter should be economically most reasonable on the second premise. In addition to the above economic analysis, the following two points should be paid attention to in designing filters:
1)单调滤波器的谐振频率会因电容,电感参数的偏差或变化而改变,电网频率会有一定的波动,这将导致滤波器失谐。设计时应保证在正常是谐的情况下滤波装置仍能满足各项要求。
1) The resonant frequency of the monotone filter will be changed by the deviation or change of capacitance and inductance parameters, and the frequency of the power grid will fluctuate to some extent, which will lead to the detuning of the filter. When designing, it should be ensured that the filter device can still meet all the requirements under normal and harmonic conditions.
2)电网阻抗变化对滤波装置尤其是其中的单调谐滤波器的滤波效果有较大影响。而更为严重的是,电网阻抗与滤波装置有发生并联谐振的可能,设计时应充分予以考虑。
2) The change of the impedance of the power network has a great influence on the filtering effect of the filter device, especially the monotone filter. What is more serious is that parallel resonance may occur between the impedance of power grid and the filter device, which should be fully considered in the design.