Patent ID: 11971437
Assignee: HYOSUNG HEAVY INDUSTRIES CORPORATION
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G  H

Claim 2:
3. The grid voltage phase detector of claim 1, wherein the first filter and the fourth filter individually have filtering characteristics of having a form of bilateral symmetry divided into equal right and left sides based around a rated frequency point in the coordinate with frequency and magnitude in an exponential scale;
the second filter has filtering characteristics of having points falling near to a straight sloped line at upper frequencies belonging to the filtering cutoff frequencies and having a certain magnitude at lower frequencies belonging thereto in the coordinate with frequency and magnitude in an exponential scale;
the third filter has filtering characteristics of having points falling near to a straight sloped line at lower frequencies belonging to the filtering cutoff frequencies and having a certain magnitude at upper frequencies belonging thereto in the coordinate with frequency and magnitude in an exponential scale.