A novel design of the low-pass filter in the harmonic detecting method based on the instantaneous reactive power theorem

The paper researched the application of the ButterWorth low-pass filter in the instantaneous reactive power theorem for the fundamental reactive current detecting and the harmonic current detecting.The shortcoming of the low-pass filter is exposed when only a ButterWorth low-pass filter or an Average low-pass filter is adopted. The paper proposed a new method to design the low-pass filter which used a ButterWorth filter and an Average filter. The result of simulation shows that it can detect the harmonic current and the fundamental reactive current precisely and quickly when the optimized low-pass filter is adopted.13figs.,1tab.,8refs.