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1. 发明专利

JPH10322888A METHOD AND SYSTEM FOR LOCATING GROUND FAULT ON POWER LINE 失效
公开(公告)号：JPH10322888A
公开(公告)日：1998-12-04
申请号：JP12525997
申请日：1997-05-15
申请人： HITACHI LTD , TOKYO ELECTRIC POWER CO
发明人： KANAI MINORU , IWASHITA KIYOJI , NAKAMURA MITSURU , YOKOYAMA HIROSHI , KUROSAWA AKIHIRO
IPC分类号： H02H3/40
摘要： PROBLEM TO BE SOLVED: To locate a ground fault on a power line quickly by calculating the distance to a ground fault point from a detecting means based on system constants for calculation when a decision is made that a detected electric waveform matches a calculated electric waveform. SOLUTION: A decision is made that a ground fault occurred on the distribution line of slave stations 10, 11 having phase inversion by locating the point on the distribution line where the phase of zero-phase current is inverted. Waveform of the zero-phase current is then calculated at the fixing point of a sensor 6 adjacent to the faulty section and the ground fault point, the ground fault resistance and various system constants are updated repeatedly until a decision is made that a measured waveform matches a calculated waveform. When a decision is made that the waveforms match each other, the distance to the ground fault point is calculated from the line reactance and the distance from the fixing point of the sensor 6 to the ground fault point is outputted to a display section. According to the arrangement, ground fault can be located surely using a relatively small number of sensors regardless of variation in the system configuration or the ground fault resistance.

2. 发明专利

JPS6174222A Vacuum breaker 失效
公开(公告)号：JPS6174222A
公开(公告)日：1986-04-16
申请号：JP19473384
申请日：1984-09-19
申请人： Hitachi Ltd
发明人： KUROSAWA YUKIO , IWASHITA KIYOJI , MATSUMOTO MORIHISA , WATANABE RYUJI
IPC分类号： H01H33/66 , H01H1/02
CPC分类号： H01H1/0203

3. 发明专利

JPS585929A ELECTRODE FOR VACUUM BREAKER 失效
公开(公告)号：JPS585929A
公开(公告)日：1983-01-13
申请号：JP10341081
申请日：1981-07-03
申请人： HITACHI LTD
发明人： IWASHITA KIYOJI , KUROSAWA YUKIO , WADA AKIRA
IPC分类号： H01H33/66

4. 发明专利

JPS57212719A VACUUM BREAKER 失效
公开(公告)号：JPS57212719A
公开(公告)日：1982-12-27
申请号：JP9652381
申请日：1981-06-24
申请人： HITACHI LTD
发明人： KUROSAWA YUKIO , WADA AKIRA , IWASHITA KIYOJI , TSUDA HIDEAKI
IPC分类号： H01H33/66 , H01H33/664

5. 发明专利

JPS57199125A ELECTRODE FOR VACUUM BREAKER 失效
公开(公告)号：JPS57199125A
公开(公告)日：1982-12-07
申请号：JP8248881
申请日：1981-06-01
申请人： HITACHI LTD
发明人： WATANABE RIYUUJI , ANDOU HISASHI , IWASHITA KIYOJI
IPC分类号： H01H33/66

6. 发明专利

JPS54100818A PRINTING METHOD AND ITS DEVICE 失效
公开(公告)号：JPS54100818A
公开(公告)日：1979-08-08
申请号：JP527278
申请日：1978-01-23
申请人： HITACHI LTD
发明人： IWASHITA KIYOJI , NARUSHIGE SHINJI
IPC分类号： B41J2/225 , B41J2/27

7. 发明专利

JPS5429001A ERASING RESIDUAL MAGNETISM IN BIG CORE 失效
公开(公告)号：JPS5429001A
公开(公告)日：1979-03-03
申请号：JP9418277
申请日：1977-08-08
申请人： HITACHI LTD
发明人： IWASHITA KIYOJI , TOMITA SADAMI
IPC分类号： H01F27/24 , H02K15/00 , H02K15/02
摘要： PURPOSE:To enable an operation of demagnetization simplified, with only a small capacity of power source enough for magnetism erasing, by a method of overlapping DC and AC magnetic field for erasing a residual magnetism in field cores of generator.

8. 发明专利

JPS5241803A STATOR CORE OF ROTARY ELECTRIC MACHINE 失效
公开(公告)号：JPS5241803A
公开(公告)日：1977-03-31
申请号：JP11644775
申请日：1975-09-29
申请人： HITACHI LTD
发明人： IWASHITA KIYOJI , SATOU MASANORI , SANO MASAAKI
IPC分类号： H02K1/16
摘要： PURPOSE:A stator core of the rotary electric machine capable of reducing the strain of the flux wave form and the temperature rise, and of increasing the core loss of the whole stator core.

9. 发明专利

JPH05292670A 失效
公开(公告)号：JPH05292670A
公开(公告)日：1993-11-05
申请号：JP9058792
申请日：1992-04-10
申请人： HITACHI LTD
发明人： KANAI MINORU , IMAMURA YUZURU , IWASHITA KIYOJI , TERADA YASUHIRO
IPC分类号： H02J3/12 , H02J3/38
摘要： PURPOSE:To maintain the voltage of a distribution system within a proper range when a dispersed power supply is connected to the distribution system and operated. CONSTITUTION:Dispersed power supplies 9a, 9b are connected to a distribution line 7b directly or through an AC converter 10. A voltage time waveform V2 and a current time waveform I2 in the vicinity of the node of the distribution line 7b and a current time waveform Id2 delivered between the distribution line 7b and the dispersed power supply 9b are detected by a voltage sensor 11 and current sensors 12, 13 and taken into a conatroller 14 at the time of the dispersed power supply 9b. A voltage value on the secondary side, the distribution system side, of a transformer 3 for the distribution of electrical energy is also detected by a voltage sensor 17 and taken into the controller 14. The controller 14 controls the dispersed power supplies 9a, 9b or the AC converter 10 on the basis of these input information. Accordingly, the voltage of a distribution system can be maintained within a proper range.

10. 发明专利

JPH0568344A DISTRIBUTION SYSTEM DISTRIBUTED POWER CONTROL SYSTEM 失效
公开(公告)号：JPH0568344A
公开(公告)日：1993-03-19
申请号：JP22704991
申请日：1991-09-06
申请人： HITACHI LTD
发明人： KANAI MINORU , HIRASAWA KUNIO , INAGAKI KEIZO , IMAMURA YUZURU , IWASHITA KIYOJI , KUDO HIROYUKI
IPC分类号： H02J3/46
摘要： PURPOSE:To prevent the decline in power quality and reliability of the distribu tion system due to a distributed power source and to operate the distribution system very efficiently by means of the distributed power source when the distributed power source is connected to the distribution system and is operated by the giving and receiving of power with the distribution system. CONSTITUTION:A distributed power source 9 is connected through a switch 8 to a distribution line 7b to be connected to a three-phase bus 5 of a transformer station 2. The voltage Vs of the distribution line 7b, the currents Is1, Is2 near a connection P between the distributed power source 9 and the distribution line 7b, and the giving and receiving current Id between the distributed power source 9 and the distribution system are detected by a voltage sensor 12 and current sensors 13, 14, 15 respectively and the detected outputs are inputted into a controller 11. Based on these inputted information, the controller 11 controls the distributed power source 9 or the connection between the distributed power source and the distribution line 7b.

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