ADAPTIVE ONLINE FILTER FOR DC OFFSET ELIMINATION

摘要

A phase angle detector with a PLL, a power converter, and a method for reducing offsets in an input signal, in which an adaptive offset processor selectively removes a DC offset component from the input signal to generate a modified signal including a fundamental frequency component and higher order harmonics of the input signal with the DC offset component removed, and the PLL provides a phase angle signal at least partially according to the modified signal.

主权项

1. A method for reducing at least one offset component in an input signal, the method comprising:
using an adaptive tracking filter having an adaptive passband defined by a frequency signal, removing substantially all frequency components of the input signal that are outside the passband to generate a fundamental frequency signal; subtracting the fundamental frequency signal from the input signal to generate a first modified signal with a fundamental frequency component substantially removed; using a low pass filter having a cutoff frequency, removing substantially all high frequency components above the cutoff frequency from the first modified signal to generate a second modified signal including a DC offset component with the fundamental frequency component and higher order harmonics substantially removed; and subtracting the second modified signal from the input signal to generate a third modified signal substantially including the fundamental frequency component and higher order harmonics of the input signal with the DC offset component substantially removed.