| 摘要 |
A frequency estimating device and a method using an orthogonal filter are provided to reduce an error caused due to noise included in a signal by estimating frequency through a signal filtered by the orthogonal filter. A frequency estimating device(100) using an orthogonal filter(120) is composed of an A/D(Analog To Digital) conversion unit(110) for converting an input current or voltage value into a digital signal; a cosine filter(122) for extracting a cosine signal from the digital signal converted in the A/D conversion unit; a sine filter(124) for extracting a sine signal from the digital signal converted in the A/D conversion unit; and a frequency estimating unit(130) for sampling the signals output from the cosine and sine filters at regular intervals of time and estimating the frequency for the digital signal by using the sampled signals. |
