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Title:
METHOD AND DEVICE FOR COMPENSATING UNBALANCED VOLTAGE AND METHOD AND DEVICE FOR CONTROLLING THREE-PHASE CONVERTER
Document Type and Number:
Japanese Patent JP2011120427
Kind Code:
A
Abstract:

To derive an instantaneous value of a Y-phase voltage of a Y-connection mutually having a phase difference of 120 degrees from the instantaneous value of a line voltage in the three-phase AC unbalanced voltage compensation.

The instantaneous values of a three-phase unbalanced voltage and a zero-phase voltage of the Y-phase voltage mutually having a phase difference of 120 degrees are derived from the instantaneous value of the three-phase unbalanced voltage of the line voltage by using the three-phase unbalanced line voltage in a general three-phase distribution system as an object and employing a conversion method from the line voltage to the Y-phase voltage by a gravity vector operation. Power conversion, in which PWM conversion is applied to a three-phase AC voltage to output a DC voltage, includes a gravity vector operation process for finding the Y-phase voltage mutually having a phase difference of 120 degrees from each line voltage, a symmetrical component calculation process for calculating a symmetrical component voltage in a three-phase balanced system from the Y-phase voltage found in the gravity vector operation process, and an unbalanced voltage compensation process for forming a compensation signal to compensate the unbalanced voltage of the three-phase AC voltage and generating a control signal for outputting the DC voltage by applying the PWM conversion of the three-phase AC voltage.


Inventors:
YUZURIHARA ITSUO
TAKAYANAGI ATSUSHI
HATA YOSHIHISA
Application Number:
JP2009277824A
Publication Date:
June 16, 2011
Filing Date:
December 07, 2009
Export Citation:
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Assignee:
KYOSAN ELECTRIC MFG
International Classes:
H02J3/12; H02M7/12
Domestic Patent References:
JP2008141887A2008-06-19
JP2004208345A2004-07-22
JPH06113466A1994-04-22
JPH1198856A1999-04-09
Attorney, Agent or Firm:
Akio Shionoiri