基于FPGA和瞬时无功功率理论的谐波检测方法

Harmonic Detection Method Based on Instantaneous Reactive Power Theory and FPGA

在本文中讨论了瞬时无功功率理论对电网的三相对称电流的变换,当电网电压为正弦波时,有功电流iP(无功电流iq)只含有6n次谐波(n为正整数),并由此设计出积分算法低通数字滤波器。该滤波器能有效的滤除6n次谐波。将该方案用FPGA器件加以实现,设计中采用了流水线结构的滤波器,大大的提高了FPGA的运算速度并节省了面积。实验仿真证明:这种检测算法可以灵活的处理综合的面积和速度的约束关系,使最后设计达到最优,具有较高的实用价值。

Based on the instantaneous reactive power theory , tri-phase currents in power system can be transformed into the active current iP and the reactive current iq. If the tri-phase currents are three-phase symmetric , iP （iq） contains only 6n harmonics （ n is integer） . In this paper an integral algorithm lowpass digital filter is designed. The direct current in iP （iQ） can pass through this filter damplessly , while 6n harmonics damp thoroughly. A hardware realization module is designed based on FPGA. From the experiment outcome, a conclusion is gained that the connection between synthesis area restriction and speed restriction can be flexibly optimized and result of simulation shows that the scheme is reliable.