Title:
FREQUENCY DETECTING DEVICE
Document Type and Number:
Japanese Patent JP2004029032
Kind Code:
A
Abstract:
To provide a device which detects frequencies without using phase detectors and counters.
In the device, values of voltage VR, VS and VT of a three-phase AC power source are converted into values of voltage Vd, Vq on d-q axes rotation coordinates rotating at a reference angular rate ω0 (101), and an angular rate ω' of the voltage vector is calculated (103, 104 and 105), and then the angular rate ω' of the voltage vector is added to the reference angular rate ω0 (106) and thereby calculating the frequency f of the three-phase AC power source (107).
Inventors:
YAMAMOTO TOUMA
Application Number:
JP2003310869A
Publication Date:
January 29, 2004
Filing Date:
September 03, 2003
Export Citation:
Assignee:
MITSUBISHI ELECTRIC CORP
International Classes:
G01R23/12; G01R23/14; G01R25/04; (IPC1-7): G01R23/12
Attorney, Agent or Firm:
Toshihide Kodama
Masuo Oiwa
Takenaka Ikuo
Keigo Murakami
Masuo Oiwa
Takenaka Ikuo
Keigo Murakami
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