Title:
PHASE DETECTION DEVICE AND METHOD
Document Type and Number:
Japanese Patent JP3264612
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To continue operation when the power supply of, for example, a thyristor (including GTO) phase control power converter incorporating a phase detection device fails (for example, grounding, phase interruption, and three- phase unbalance) by detecting synchronization phase even if a multiple-phase AC input signal is unbalanced.
SOLUTION: A first internal sinusoidal wave signal eq and a second internal sinusoidal wave signal ed which differs from the signal eq by a specific phase θ0 are generated according to a count value obtained by integrating an internal reference frequency command value 9. The signals eq and ed are inputted and one-phase AC signal eaq = Ea × sin θa out of AC input signals whose phase is to be detected is inputted, thus calculating a phase difference Δθ between the signals eqa and eq. An internal reference frequency command value 9 is corrected by a signal in response to the phase difference Δθ and the minimum phase difference Δθ is controlled to be reduced. The same synchronization phase is detected also for other phases ebq and ecq in the above AC input signal.
Inventors:
Noboru Azusawa
Yoji Miyahara
Masanobu Nemezawa
Atsushi Nishioka
Yoji Miyahara
Masanobu Nemezawa
Atsushi Nishioka
Application Number:
JP30556795A
Publication Date:
March 11, 2002
Filing Date:
November 24, 1995
Export Citation:
Assignee:
株式会社日立製作所
International Classes:
G01R25/08; G01R25/04; H02H7/09; H02M1/08; H03L7/085; (IPC1-7): G01R25/04; H02M1/08; H03L7/085
Domestic Patent References:
| JP5627664A | ||||
| JP2145978A | ||||
| JP5172874A | ||||
| JP6037711B1 |
Attorney, Agent or Firm:
Yoshihiro Takasaki