专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

11. 发明专利

JP2000224896A DC TRANSMISSION-CONTROLLING DEVICE 失效
公开(公告)号：JP2000224896A
公开(公告)日：2000-08-11
申请号：JP2520199
申请日：1999-02-02
申请人： HITACHI LTD , KANSAI ELECTRIC POWER CO , SHIKOKU ELEC POWER , ELECTRIC POWER DEV CO
发明人： SEKOGUCHI MASAHIRO , GOTO MASUO , MADORI IWAO , YOSHIZUMI TATSUNORI , AZUMA MASAKI , MURAKAMI HIROAKI , KATO KAZUO
IPC分类号： H02J3/36 , H02P9/00
摘要： PROBLEM TO BE SOLVED: To detect a frequency other than a shaft torsional vibration frequency region according to the bus voltage of a DC conversion station, and to efficiently suppress and control shaft torsion. SOLUTION: A device is equipped with frequency detectors 142a-142c that detect frequencies fa, fb, and fx of each phase according to phase voltages Va, Vd, and Vc of an AC bus 5 of a DC conversion station being connected to a generator 2, an averaging circuit 143 that obtains the average value of the frequencies fa, fb, and fc for detecting the frequency of the bus 5, a filter 144 and a judgment circuit 145 that detect shaft torsional vibration according fluctuation in the frequency of the bus 5, a filter 147 that detects a control signal for suppressing the detected shaft torsional vibration, and an adder 150 that adds the control signal to the output of a constant current-controlling device 149. By the output of the adder 150, the control angle of the DC conversion station is adjusted for suppressing the shaft torsional vibration.

12. 发明专利

JPH10201079A PROTECTOR FOR DC TRANSMISSION LINE 失效
公开(公告)号：JPH10201079A
公开(公告)日：1998-07-31
申请号：JP358597
申请日：1997-01-13
申请人： HITACHI LTD , KANSAI ELECTRIC POWER CO , SHIKOKU ELEC POWER , ELECTRIC POWER DEV CO
发明人： AMANO MASAHIKO , KONISHI HIROO , YOSHIZUMI TATSUNORI , AZUMA MASAKI , UEHARA NOBUKAZU , HONJO NOBUYUKI
IPC分类号： H02H3/26 , H02J1/00
摘要： PROBLEM TO BE SOLVED: To provide a protector for a DC transmission line which is capable of high-speed accident judgment without malfunction by reducing errors in charge current compensation by simple method. SOLUTION: The measured values of DC currents and DC voltage are reduced for high frequency components by a low pass filter 62 after being sampled by an input processor 61. A charge current computer 62 computes the amount of compensation of charge currents by difference computation. The value being left after subtracting the component of compensation of charge currents from the measured value of the DC current is sampled with a sample & hold circuit 64, and is transmitted to the other end. The sampled value is inputted into an operation judger 65 together with the value transmitted from the other end. The operation judger obtains the quantity of operation, taking the difference between both ends, and in case that the quantity of operation is larger than the sensitiveness of the relay, this sends out an operation signal to a controller, judging it as an accident. Hereby, high-speed accident judgment becomes possible without malfunction caused by charge currents.

13. 发明专利

JPH11289670A TWO-POLE DC POWER TRANSMISSION SYSTEM 失效
公开(公告)号：JPH11289670A
公开(公告)日：1999-10-19
申请号：JP9159098
申请日：1998-04-03
申请人： HITACHI LTD , HITACHI ENG CO LTD
发明人： YOSHIZUMI TATSUNORI , MIKAMI HIROSHI
IPC分类号： G01R31/02 , H02H7/12 , H02J1/00 , H02J3/36 , H02M1/00
摘要： PROBLEM TO BE SOLVED: To automatically adjust an AC voltage for ground detection, by judging the operating state of each DC power transmission system based on the switched state of a switch provided at the return pole DC line, and by adjusting the output voltage of an AC power supply. SOLUTION: When an AC power supply device 25 is connected only to a return line 6 on two-pole operation, the AC voltage of a capacitor 22 of the AC power supply device 25 is applied to the return line 6 via a capacitor 23 and a switch 54 and, furthermore, is applied to a return line 7 via a circuit breaker 13 and a switch 56. In this case, when a grounding accident occurs at F1 point of the return line 6, an AC current flowing to the grounding circuit of the return line 6 bypasses one part of the return-line 6, thus increasing the AC current, and hence detecting the occurrence of the grounding accident at the return line 6 by a grounding detection relay 16. At this time, a return line protection device 80 controls AC power supplies 20 and 20 based on the state signal of switches 14, 15, 53, 54, 55, and 56 and the circuit breaker 13 and constantly controls current being allowed to flow to each return line regardless of an operating state.

14. 发明专利

JPS61214716A REGULAR MONITORING 失效
公开(公告)号：JPS61214716A
公开(公告)日：1986-09-24
申请号：JP5229985
申请日：1985-03-18
申请人： HITACHI LTD
发明人： YOSHIZUMI TATSUNORI , MASUKO SHOICHI
IPC分类号： H02H3/05 , H02H3/28

你已经成功收藏专利！

检索式保存成功!

IPRDB

热门服务

关于我们

友情链接

联系方式