Apparatus and method for real time harmonic spectral analyzer

摘要

In one embodiment, a measuring device may comprise two oscillators. The first oscillator may generate a local reference signal in a frequency detector to detect a fundamental frequency of the alternating current (AC). The second oscillator may generate two substantially mutually orthogonal sinusoid signals having the selected frequency. The measuring device further may comprise a first group of multipliers that mixes the two sinusoid signals with a current and a voltage data signal of the AC respectively, a group of low-pass filters for removing high frequency components from the multiplication products, a second group of multipliers for mixing the filtered multiplication products respectively, and a plurality of adders each to sum together a pair of multiplication products of the second group of multipliers.

主权项

1. A device for measuring power of an alternating current (AC) comprising:
a frequency detector having a first oscillator to generate a local reference signal to detect a fundamental frequency of the AC and a controller to generate a control signal indicating the detected fundamental frequency of the AC; and a power analyzer to analyze power of the AC, the power analyzer comprising:
a second oscillator, to receive the control signal from the frequency detector, to generate first and second substantially mutually orthogonal sinusoid signals at a programmable harmonic of the fundamental frequency;a first group of multipliers for mixing the first and second sinusoid signals with a current data signal and a voltage data signal of the AC respectively;a group of low-pass filters for respectively removing high frequency components from a multiplication product of the first group of multipliers;a second group of multipliers for respectively mixing the filtered multiplication products; anda plurality of adders each to sum together a pair of multiplication products of the second group of multipliers.