公开(公告)号：US20150286227A1

公开(公告)日：2015-10-08

申请号：US14418236

申请日：2013-07-24

Applicant: Hitachi, Ltd. ,  Tohoku Electric Power Co., Inc. ,  Tohoku Electric Manufacturing Co., Ltd.

Inventor： Masahiro Watanabe ,  Ryo Egashira ,  Kenichiro Yamane ,  Katsuhiro Matsuda ,  Takafumi Futakami ,  Toshiyuki Seto ,  Jun Murakoshi

IPC: G05F1/14

CPC classification number: G05F1/14 ,  H02J3/1878 ,  Y02E40/12 ,  Y02E40/30

Abstract: A voltage adjustment device, a voltage adjusting method and a power control system for a distribution system are provided, in which the voltage adjustment device and a static var compensator are appropriately operated in a coordinated manner and the sustention of voltage and the enhancement of the operation efficiency are attained. A voltage adjustment device for a distribution system is installed in the distribution system including a static var compensator on an end side and controls a secondary voltage to be within a predetermined limit value by adjusting a tap position. The voltage adjustment device includes a first unit configured to estimate the secondary voltage; a second unit configured to obtain a corrected voltage by correcting the estimated secondary voltage by using a correction amount obtained from an output of the static var compensator; and a third unit configured to compare the corrected voltage with the predetermined limit value and operate the tap position when the corrected voltage deviates from the predetermined limit value.

Abstract translation: 提供一种用于配电系统的电压调节装置，电压调节方法和功率控制系统，其中电压调节装置和静态无功补偿器以协调的方式适当地运行并且电压的维持和操作的增强 效率达到。 用于分配系统的电压调节装置安装在分配系统中，包括端侧的静态无功补偿器，并通过调节分接头位置来控制次级电压在预定极限值内。 电压调节装置包括：第一单元，被配置为估计次级电压; 第二单元，被配置为通过使用从静态无功补偿器的输出获得的校正量来校正所估计的次级电压来获得校正电压; 以及第三单元，其被配置为将所述校正电压与所述预定极限值进行比较，并且当所述校正电压偏离所述预定极限值时，操作所述分接头位置。

公开(公告)号：US10211777B2

公开(公告)日：2019-02-19

申请号：US15113245

申请日：2015-01-14

Applicant: Hitachi, ltd. ,  Tohoku Electric Power Co., Inc. ,  Tohoku Electric Manufacturing Co., Ltd

Inventor： Masahiro Watanabe ,  Kenichiro Yamane ,  Takuya Matsumoto ,  Masatoshi Kumagai ,  Tsukasa Oonishi ,  Ryo Egashira ,  Katsuhiro Matsuda ,  Jun Murakoshi ,  Tomoya Sato

IPC: G01C21/00 ,  H02S50/00 ,  H02J3/38

Abstract: The output of a photovoltaic power generator is estimated by estimating a solar radiation amount at a point different from solar radiation measurement points and determining an estimation error amount from solar radiation values measured at limited points. A photovoltaic power generator output estimation method estimates an output of a photovoltaic power generator based on a measured solar radiation value. The method includes a first estimation method of estimating a solar radiation amount at a photovoltaic power generator installation point from solar radiation meter installation point information, a value measured by a solar radiation meter, and photovoltaic power generator installation point information; a second estimation method of estimating the solar radiation amount at the photovoltaic power generator installation point in a manner different from that of the first estimation method; an output estimation method of estimating the output of the photovoltaic power generator from an estimated solar radiation amount and a rated capacity of the photovoltaic power generator; and an error estimation method of determining an estimation error of a photovoltaic power generator output from a difference between the first and second estimation methods.

公开(公告)号：US09606554B2

公开(公告)日：2017-03-28

申请号：US14418236

申请日：2013-07-24

Applicant: Hitachi, Ltd. ,  Tohoku Electric Power Co., Inc. ,  Tohoku Electric Manufacturing Co., Ltd.

Inventor： Masahiro Watanabe ,  Ryo Egashira ,  Kenichiro Yamane ,  Katsuhiro Matsuda ,  Takafumi Futakami ,  Toshiyuki Seto ,  Jun Murakoshi

IPC: G05F1/14 ,  H02J3/18

CPC classification number: G05F1/14 ,  H02J3/1878 ,  Y02E40/12 ,  Y02E40/30

Abstract: A voltage adjustment device, a voltage adjusting method and a power control system for a distribution system are provided, in which the voltage adjustment device and a static var compensator are appropriately operated in a coordinated manner and the sustention of voltage and the enhancement of the operation efficiency are attained. A voltage adjustment device for a distribution system is installed in the distribution system including a static var compensator on an end side and controls a secondary voltage to be within a predetermined limit value by adjusting a tap position. The voltage adjustment device includes a first unit configured to estimate the secondary voltage; a second unit configured to obtain a corrected voltage by correcting the estimated secondary voltage by using a correction amount obtained from an output of the static var compensator; and a third unit configured to compare the corrected voltage with the predetermined limit value and operate the tap position when the corrected voltage deviates from the predetermined limit value.

公开(公告)号：US10677824B2

公开(公告)日：2020-06-09

申请号：US15757498

申请日：2016-06-16

Applicant: Hitachi, Ltd.

Inventor： Hirotaka Takahashi ,  Masahiro Adachi ,  Katsuhiro Matsuda

IPC: G01R21/133 ,  H02J3/38 ,  H02J3/00 ,  H02J3/18

Abstract: A distributed-generator power-generation-amount estimation apparatus and method capable of more accurately and easily estimating output by reflecting a power factor are disclosed. The apparatus estimates a power generation amount of a distributed generator interconnected to an electric power system from active power and reactive power measured at regular intervals by measurement means, the apparatus including power-factor estimation means for estimating, as a ratio of a time change amount of the active power and the reactive power, a power factor of the distributed generator interconnected to a demand side of the electric power system, distributed-generator power-generation-amount estimation means for having, from active power and reactive power measured at a time of no power when the distributed generator interconnected to the electric power system is not generating power, a first characteristic line representing a load characteristic on a coordinate plane based on active power and reactive power, a second characteristic line representing a distributed-generator characteristic on the coordinate plane, and estimating the difference between the active power and the reactive power at an intersection point of the first characteristic line and the second characteristic line, and the measured active power and the measured reactive power as the power generation amount of the distributed generator, and output means for outputting power-generation-amount estimation information on the distributed generator estimated by the distributed-generator power-generation-amount estimation means.