Title:
RESIDUAL VOLTAGE COMPUTATION CIRCUIT, POWER OUTAGE DETERMINATION CIRCUIT, AND SYSTEM-LINKED DEVICE
Document Type and Number:
WIPO Patent Application WO/2015/163008
Kind Code:
A1
Abstract:
A positive sequence phase (θPOS) and a negative sequence phase (θneg) are calculated by a phase synchronization circuit (11) on the basis of the line voltage (VRS, VST) of a three-phase system. In DQ converters (12a, 12b), the line voltage (VRS, VST) undergoes rotational coordinate transformation by the positive sequence phase (θPOS) and the negative sequence phase (θneg), and a positive sequence D-axis component (VPOSD,) a positive sequence Q-axis component (VPOSQ), a negative sequence D-axis component (VNEGD), and a negative sequence Q-axis component (VNEGQ) are calculated. On the basis of the positive sequence D-axis component (VPOSD) and the positive sequence Q-axis component (VPOSQ), a positive sequence component absolute value (VPOS) is calculated, and on the basis of the negative sequence D-axis component (VNEGD) and the negative sequence Q-axis component (VNEGQ), a negative sequence component absolute value (VNEG) is calculated, by absolute value computation units (13a, 13b). From the difference of the positive sequence component absolute value (VPOS) and the negative sequence component absolute value (VNEG), a differential unit (14) calculates an asymmetric residual voltage (VDIPA) which is the residual voltage not due to a fault condition at the time of a voltage drop. In so doing, the residual voltage in a circuit linked to a three-phase system can be estimated, even during any sort of fault condition occurring at the time of a voltage drop.
Inventors:
SAIKI KUNIHIKO (JP)
Application Number:
PCT/JP2015/056152
Publication Date:
October 29, 2015
Filing Date:
March 03, 2015
Export Citation:
Assignee:
MEIDENSHA ELECTRIC MFG CO LTD (JP)
International Classes:
G01R19/165; G01R29/16
Foreign References:
| JP2004156986A | 2004-06-03 | |||
| JPS5644346A | 1981-04-23 | |||
| JP2006014546A | 2006-01-12 |
Attorney, Agent or Firm:
KOBAYASHI, Hiromichi et al. (JP)
Hiromichi Kobayashi (JP)
Hiromichi Kobayashi (JP)
Download PDF: