风电并网逆变器无源滤波器设计

Design of Passive Filter for Integrated Wind Power Inverter Power

在风力发电并网时会存在高次谐波,注入电网后会对电能质量造成危害,网侧对PWM输出电压的滤波必不可少,目前大量采用LCL滤波器代替L、LC滤波器,但LCL滤波器存在谐振现象,增加阻尼消振又会带来功率损耗。针对以上问题提出一种新型滤波器,采用双电解电容并联二极管的LCL结构,给出了参数设计方法。通过仿真分析证明了该新型滤波器解决了谐振带来的不稳定问题,去掉了阻尼电阻,减小了滤波器功耗同时减小了滤波器的体积。

High-order harmonic produced in wind power grid will cause harm to the grid power quality, so filtering of PWM output voltage in network side is essential. Currently, LCL filter is extensively used in place of L and LC filter; however, resonance phenomenon exists in the LCL filter and the power loss tends to increase when the damping is used to reduce the resonance. In view of the problems above, a new type of filter is presented in this paper which uses double electrolytic capacitor parallel diode structure of the LCL, and the parameter design method is also given. It can be proved by simulation that this new filter can be used to solve the instability problem caused, remove the damping resistance, reduce the filter power consumption and the volume of the filter.