At last the components of the system are modeled and simulated with matlab software . the simulation results indicate that the combined system can reduce the capacity of apf effectively , detecting the harmonic current effectively , compensating harmonic current effectively 结果表明，对单位容量的谐波源，采用与可变参数lc滤波器混合使用的并联型有源电力滤波器系统，能够有效地减少有源滤波器的容量，有效地检测出高次谐波分量，并进行谐波补偿，使系统的电流波形基本保持正弦。
In the last few years , the polution and harm of harmonic hi the power system is becoming more and more serious . the lc passive filter that is used widely ca n ' t satisfy the new demands of harmonic filter . the combined system of shunt lc passive filter and active power filter are put forward , and this paper focus on the following four aspects . 1 近年来，电力系统谐波的污染和危害日趋严重，而国内普遍使用的lc无源滤波器逐渐不能适应滤波的新要求，本文提出了与可变参数lc滤波器混合使用的并联型有源电力滤波器系统，并着重研究了以下几个主要问题： 1 、 lc无源滤波器(主要是高通滤波器)参数调节对阻抗特性和无功补偿的影响。
The variable parameter taper equation was built with diameter determination datas of different parts of cryptomeria fortunei plantation sample wood , in combination with the relative tree height curve mode and other assistant equations , volume table of c . fortunei plantation standing was compiled , and provided the scientific basis for the production and application 摘要利用柳杉人工林样木各部位直径测定数据，建立可变参数削度方程，配合威布尔分布函数、相对树高曲线模型及其他辅助方程，编制了柳杉人工林林分出材率表，为生产应用提供科学依据。
