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11. 发明专利

JP2004022847A Current transformer, power unit, and sensor system 审中-公开
公开(公告)号：JP2004022847A
公开(公告)日：2004-01-22
申请号：JP2002176517
申请日：2002-06-18
申请人： Hitachi Ltd , 株式会社日立製作所
发明人： OGAWA KENJI , WATANABE MASAHIRO
IPC分类号： H01F38/28
摘要： PROBLEM TO BE SOLVED: To improve the power converting efficiency of a current transformer, a power unit, and a sensor system by accurately making the split surfaces of a core used for the transformer, unit, and system coincide with each other. SOLUTION: Each of the current transformer, power unit, and sensor system has a core composed of a magnetic material, a winding wound around the core and composed of a conductor, and a package supporting the core. The core is constituted by splitting the core into two or more portions, and an elastic body, such as the spring, sponge, etc., is arranged between at least one split portion of the core and the package. Consequently, the split surfaces of the core used for the current transformer, power unit, and sensor system can be accurately made to coincide with each other, and the power converting efficiency of the transformer, unit, and system is improved. COPYRIGHT: (C)2004,JPO

12. 发明专利

JP2003043077A Higher harmonic measuring equipment 审中-公开
标题翻译：更高谐波测量设备
公开(公告)号：JP2003043077A
公开(公告)日：2003-02-13
申请号：JP2001233389
申请日：2001-08-01
申请人： Hitachi Ltd , Tokyo Electric Power Co Inc:The , 東京電力株式会社 , 株式会社日立製作所
发明人： YASUKAWA SABURO , NAMIKATA KIYONORI , OGAWA KENJI , KOGURE EIJI , KIKUCHI TOSHIHIRO , OGIWARA YOSHINORI , MAKI MAKOTO
IPC分类号： G01R27/02 , G01R19/00 , G01R23/20 , H02H3/52
摘要： PROBLEM TO BE SOLVED: To solve such a problem that it has been impossible to avoid the size of an oscillator becoming larger, which is required conventionally for taking following current measures, insulation measures for example, to deal with a current of a three-phase power system noise currents which flow in the oscillator in a harmonic current injector.
SOLUTION: Reduction in the size of the oscillator 8 is realized, by causing the harmonic current injector 13 to have an oscillator 8 and a filter 9 which causes only a power-system 1 side current to flow, and causing only noise currents to flow in the oscillator 8.
COPYRIGHT: (C)2003,JPO
摘要翻译：要解决的问题：为了解决这样的问题，即不可能避免振荡器的尺寸变大，这是传统上用于采取以下电流措施所需要的绝缘措施，例如，以处理三相电流在谐波电流注入器中在振荡器中流动的电力系统噪声电流。解决方案：通过使谐波电流注入器13具有振荡器8和滤波器9来实现振荡器8的尺寸的减小，该振荡器8和滤波器9仅使电力系统1侧电流流动，并且仅使噪声电流流入振荡器8。

13. 发明专利

JP2002071726A VOLTAGE SENSOR 失效
公开(公告)号：JP2002071726A
公开(公告)日：2002-03-12
申请号：JP2000263252
申请日：2000-08-28
申请人： HITACHI LTD
发明人： HAYASHIBARA MITSUO , WATANABE MASAHIRO , KATO KAZUO , TANI MASAYUKI , OGAWA KENJI
IPC分类号： G01R15/06 , G01R19/00
摘要： PROBLEM TO BE SOLVED: To provide a voltage sensor which can measure a voltage (potential) of a measurement object highly accurately in a non-contact and nongrounding manner without an operation of setting and separating the sensor to the measurement object even when a stray capacity between the sensor and the ground is unknown. SOLUTION: In the non-contact voltage sensor for measuring the voltage of the measurement object without bringing a conductive object into direct contact with the measurement object, a voltage or a current from the sensor is overlapped with a voltage of the measurement object to a voltage reference point or with a current flowing in the measurement object, and the overlapped voltage or current applied to a circuit part connected electrostatically to the measurement object and connected electrostatically via the stray capacity to the voltage reference point is detected, whereby the voltage of the measurement object is measured.

14. 发明专利

JP2002014120A INSTRUMENT FOR MEASURING HIGHER HARMONICS 失效
公开(公告)号：JP2002014120A
公开(公告)日：2002-01-18
申请号：JP2000197888
申请日：2000-06-27
申请人： HITACHI LTD , TOKYO ELECTRIC POWER CO
发明人： YASUKAWA SABURO , KAWASE MINORU , OGAWA KENJI , WATANABE MASAHIRO , OUCHIDA HIDEYA
IPC分类号： G01R15/14 , G01R15/18 , G01R23/20
摘要： PROBLEM TO BE SOLVED: To solve the problems that conventionally for practical use the size of an instrument becomes large and that a cost thereof becomes high, because impedances are required to be provided plurally instrument in matching with the order of the high-frequency waves to be measured. SOLUTION: This higher-harmonic measuring instrument 1 is markedly reduced in size, because the oscillation frequency is regulated using one oscillator 13a, while matching with the order of the high-frequency waves, by connecting a switch 13B between the higher-harmonic impedance Zan and the higher- harmonic measuring instrument 1, and by making the n-th order higher-harmonic current generated in the oscillator 13A connected between a current transformer 4 and a transformer 15 flow in the measuring instrument 1 by closing the switch.

15. 发明专利

JPS60240376A FIXED TUBE WELDING DEVICE 失效
公开(公告)号：JPS60240376A
公开(公告)日：1985-11-29
申请号：JP9654184
申请日：1984-05-16
申请人： HITACHI LTD , HITACHI SEIKO KK
发明人： MIYAMOTO TOSHIO , OONISHI AKIRA , MURAKAWA YASUYUKI , OGAWA KENJI , OBARA YUUJI
IPC分类号： B23K9/028
摘要： PURPOSE:To obtain a titled device that enables welding of the whole circumference using one welding head for many kinds of tube diameters by holding the tube and welding head by separate supports and enabling to set the amount of shifting of a torch optionally. CONSTITUTION:A head 16 attached to a support 17 for the welding head having a freely movable arm is put on the welding positon of a fixed tube 3 attached to a supporting device 18 for tube, and center points of a truck 12 and the tube 3 are made to coincide. A welding torch 2 is shifted to a specified position by a driving motor 5 for moving the torch 2 vertically, and after fixing, a specified reference voltage is set by a variable resistance 10, and a truck 12 driving motor 13 is operated to make the whole circumference welding of the tube 3. If the tube 3 is deviated from the center of rotation of the torch 2, an arc voltage changes. In this case, a constant voltage controlling device 11 compares the arc voltage with the reference voltage and sends a signal to the motor 5 to make the two equal, and moves the torch 2. Accordingly, the torch 2 is controlled to rotate around the tube 3 always at a fixed distance.

16. 发明专利

JP2002252980A CURRENT TRANSFORMER INPUT TYPE POWER UNIT 失效
公开(公告)号：JP2002252980A
公开(公告)日：2002-09-06
申请号：JP2001051259
申请日：2001-02-26
申请人： HITACHI LTD
发明人： WATANABE MASAHIRO , KATO KAZUO , OGAWA KENJI , UENO ISAO
IPC分类号： H02M7/12 , H02M7/217 , H02M7/219
摘要： PROBLEM TO BE SOLVED: To provide a current transformer input type DC power unit, which has a simple constitution and a less power loss. SOLUTION: An AC switch 20 for short-circuiting a secondary winding 120 of a current transformer 10, comprises of field-effect transistors 211 to 214, which is a low on-resistance switch having no offset voltage generated at the time of current rise, so that the power loss occurring at the time of an excessive input is reduced, and the volt-ampere at the time of the maximum operation of the secondary winding 120 is limited to a minimum so that the current transformer is miniaturized.

17. 发明专利

JPH09289535A INFORMATION COMMUNICATION DEVICE 失效
公开(公告)号：JPH09289535A
公开(公告)日：1997-11-04
申请号：JP10279796
申请日：1996-04-24
申请人： HITACHI LTD
发明人： OGAWA KENJI , KIDO MITSUYASU
IPC分类号： G01R31/00 , H02H3/00 , H02H7/26 , H04L29/14
摘要： PROBLEM TO BE SOLVED: To add a communication test function for a single communication relay device and a total communication test function for the whole existent relay protection system to the existent relay protection system. SOLUTION: Respective relay devices 10a, 10b, and 10c installed in the relay protection system are equipped with alteration circuits 128 and 129 which generate transmission errors in a common frame to be sent to a next station according to a test information table stored in a RAM 112 and a test circuit 122 which detects a defect of a transmission system by performing inspection, etc., as to whether the transmitted common frame format is proper. The common frame is issued by the relay device 10a and makes a round through other stations 10b and 10c along two optical transmission routes 1000 and 1001 while sequentially gathering system electric energy data at respective terminals.

18. 发明专利

JP2001028833A METHOD AND DEVICE FOR GROUNDING DETECTION 失效
公开(公告)号：JP2001028833A
公开(公告)日：2001-01-30
申请号：JP19737699
申请日：1999-07-12
申请人： HITACHI LTD
发明人： YASUKAWA SABURO , KAWASE MINORU , OGAWA KENJI , WATANABE MASAHIRO
IPC分类号： H02H7/26 , H02H3/38
摘要： PROBLEM TO BE SOLVED: To obtain a high precision ground detection device which is not influenced by tap change of a PC earth system. SOLUTION: Ground detection sensors 3 are provided at a plurality of positions of a distribution system 2 which has a main transformer 1 whose neutral is earthed with a Pedersen Coil(PC) 4 with taps 4a. Zero phase voltages V0 and zero phase currents I0 which are detected by the respective sensors 3 are received by ground detection circuits 102 to detect the ground and judge the direction. If the polarity of V0-I0 phase difference (for instance 90±) with V0 as a reference is (+), it is judged that the ground point is on the terminal side and, if the polarity is (-), it is judged that the ground point is on the power supply (transformer) side. A frequency with the phase difference is evaluated is not lower than a system resonance frequency determined from a reactor L and a ground capacitance C. For instance, the frequency is within a frequency region which is not lower than a maximum system resonance frequency when L of the PC 4 is minimum.

19. 发明专利

JPH10243580A DATA COLLECTING SYSTEM 失效
公开(公告)号：JPH10243580A
公开(公告)日：1998-09-11
申请号：JP3800597
申请日：1997-02-21
申请人： HITACHI LTD
发明人： OGAWA KENJI , KANAI MINORU , YOSHIKAWA TOSHIFUMI , YASUKAWA SABURO , MATSUMOTO HIDEKAZU , IWASHITA KIYOJI
IPC分类号： H02J13/00 , H04B7/24 , H04Q9/00 , H04Q11/04 , H04W40/02 , H04W40/14 , H04W40/20 , H04Q7/34
摘要： PROBLEM TO BE SOLVED: To enable a data collecting system to flexibly cope with a change in communication route resulting from a change in system constitution. SOLUTION: A master station 21 transmits retrieval packets as a retrieval station throughout its service area. When slave stations 40a and 40d receive the retrieval packets, the stations 40a and 40d return retrieval answer packets containing the addresses and coordinates of the stations 40a and 40d to the mater station 21. The master station 21 recognizes the communication routes between the station 21 and the slave stations 40a and 40d by preparing communication route tables about the communication routes based on the data contained in the received retrieval answer packets. For the retrieval answer packet from a slave station 40b, the master station 21 receives the packet through the slave station 40a which acts as a repeater station and also recognizes the communication route about the station 40b in accordance with the data contained in the received packet.

20. 发明专利

JPH06284577A METHOD AND APPARATUS FOR CONTROLLING POWER-SYSTEM VOLTAGE 失效
公开(公告)号：JPH06284577A
公开(公告)日：1994-10-07
申请号：JP6798393
申请日：1993-03-26
申请人： HITACHI LTD , CHUBU ELECTRIC POWER
发明人： KIDO MITSUYASU , CHIBA TOMIO , OGAWA KENJI , MATSUI YOSHIAKI , KITO MASAHITO , TAKAHASHI TAKESHI , ASAI MICHIO
IPC分类号： G05F1/14 , H02J3/00 , H02J3/12
摘要： PURPOSE:To provide a method and an apparatus for controlling a power-system voltage, in which the closing and cut-off time when voltage-adjusting equipment is connected or cut off is stored so that a system voltage is adjusted before the shifting time. CONSTITUTION:A first control means 1B includes a detecting means 108 for detecting a fluctuation in system voltage, a periodic-fluctuation generation certifying means 109 for detecting and storing data whether a fluctuation in voltage occurs every given time, and a condition evaluation means 110 for forecasting a system voltage after fluctuation by using a voltage, which is detected a given time earlier than the fluctuation time, and selecting a tap of a voltage regulator to modulate the fluctuation in voltage. Moreover, a second control means IC for changing the tap of the voltage regulator according to an integration value of a deviation in system voltage, and a logic processing means for selecting one of the first or second control means 1B or 1C preferably are provided.

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