专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

1. 发明专利

JPH02135834A SIGNAL SYNCHRONIZING SYSTEM 失效
公开(公告)号：JPH02135834A
公开(公告)日：1990-05-24
申请号：JP28938288
申请日：1988-11-16
申请人： TOKYO ELECTRIC POWER CO , TOSHIBA CORP , HITACHI LTD , MITSUBISHI ELECTRIC CORP
发明人： MAEDA TAKAFUMI , KANO TATSUYA , MATSUYAMA TAKAKAZU , ANZAI TOSHIO
IPC分类号： H04L7/00 , H04L12/42
摘要： PURPOSE:To attain timewise efficiency at initializing of network by applying switching control of three transit states of asynchronous new station invitation state for a short period at initializing, invitation inhibit state for synchronizing looking and synchronizing new station invitation state for a prescribed period after signal synchronization establishment. CONSTITUTION:In the initial state when a network is built up, the interval of invitation specified by the IEEE 802.4 recommendations is minimized to quicken the time till the system operation is available and when the system operation is enabled, the invitation of new station is inhibited and the signal synchronization between a master station and a slave station is established quickly and efficiently. After the establishment of signal synchronization, the invitation of new station for network expansion is executed sequentially in an individual timing by each participant station periodically without losing the synchronization establishing state. Thus, the timewise efficiency at the initialize of the network is attained.

2. 发明专利

JPH01259726A POWER SYSTEM CONTROLLER 失效
公开(公告)号：JPH01259726A
公开(公告)日：1989-10-17
申请号：JP8439288
申请日：1988-04-06
申请人： HITACHI LTD , TOKYO ELECTRIC POWER CO
发明人： NOHARA GOO , GOTO MASUO , SUZUKI MAMORU , MAEDA TAKAFUMI
IPC分类号： H02J3/00
摘要： PURPOSE:To achieve stable and accurate control, by locking a power system controller when the differentiated value of detected system frequency exceeds over a predetermined value and prohibiting unnecessary control. CONSTITUTION:Time differentiation ( f/ t) of system frequency is calculated. If it exceeds over predetermined variations L1, L2, no control is made and a controller Co is locked, thus prohibiting oversensitive control. If it is within the limits L1, L2, an interruption control command is fed to a circuit/breaker CB3 if the absolute value of the difference between the frequency (f) and a reference frequency (f0) exceeds over a predetermined judgement level (fL) while control is mode through the controller C0 if the absolute value is lower than the judgement level (fL).

3. 发明专利

JPH1080050A METHOD AND DEVICE FOR GROUND-FAULT LINE SELECTION AND PROTECTION RELAYING 失效
公开(公告)号：JPH1080050A
公开(公告)日：1998-03-24
申请号：JP23211496
申请日：1996-09-02
申请人： HITACHI LTD , TOKYO ELECTRIC POWER CO
发明人： IWATANI FUMIO , WACHI ISAO , SUZUKI YASUTAKA , ICHINOSE NORIFUMI , MAEDA TAKAFUMI
IPC分类号： G01R31/02 , H02H3/16 , H02H3/36 , H02H7/22
摘要： PROBLEM TO BE SOLVED: To detect the fault current of a ground-fault which occurs in a system by offsetting a zero-phase circulating current by means of a lesser number of line selecting and discriminating elements even when another system of a different frequency is installed in parallel. SOLUTION: An input circuit 11 fetches the zero-phase voltage V0 of a system and the difference current J0 between the zero-phase currents of the first and second lines of the system after digitization and a memory 12 delays the difference current J0 by a period of time TD longer than the discriminating time required for discriminating a ground-fault. Then an operator 13 finds the difference between the inputted difference current J0 and the output of the memory 12 and calculates the fault current of a one-line ground fault from which a zero-phase circulating current is eliminated.

4. 发明专利

JPH01259730A OUTPUT DETERMINING METHOD FOR MULTI-SERIES SYSTEM 失效
公开(公告)号：JPH01259730A
公开(公告)日：1989-10-17
申请号：JP8508588
申请日：1988-04-08
申请人： HITACHI LTD , TOKYO ELECTRIC POWER CO
发明人： NOHARA GOO , GOTO MASUO , KAWAI TADAO , YOSHIDA AKIRA , MAEDA TAKAFUMI
IPC分类号： H02J3/38
摘要： PURPOSE:To match the final output, by providing interruption signals from respective controllers to selected generators when the numbers of selected generators match. CONSTITUTION:When the frequency is at the outside of a predetermined range, effective power is compared with a target cut-off power and corresponding interruption generators 1a, 1b, 1c or combinations thereof are selected. When the number of the interruption generators in its system and other system match each other, the interruption generator in its system is selected. When the numbers do not match each other, difference of effective power between the interruption generators in its system and other system is calculated. If the difference is within a predetermined comparison value, the number of selected interruption generator in a predetermined series is selected as the number of interruption generator selected from its series. If the difference exceeds over the comparison value, the number of interruption generator is selected according to a predetermined priority.

5. 发明专利

JPH01238243A SIGNAL SYNCHRONIZING SYSTEM 失效
公开(公告)号：JPH01238243A
公开(公告)日：1989-09-22
申请号：JP6332788
申请日：1988-03-18
申请人： HITACHI LTD , TOKYO ELECTRIC POWER CO , TOSHIBA CORP , MITSUBISHI ELECTRIC CORP , HITACHI CABLE
发明人： SESHIMA YUKITO , MAEDA TAKAFUMI , KANO TATSUYA , TERAO YASUHIKO , IMAI YASUMASA
IPC分类号： H02H3/28 , H04L7/00 , H04L12/40 , H04Q9/14
摘要： PURPOSE:To execute stable signal synchronization between each station regardless of the number of a station subscribed for a network by transmitting a synchronizing signal corresponding with the number of the subscribed station for the network to a synchronous slave station from a synchronous master station. CONSTITUTION:The synchronous master station I1 transmits a vacant data frame DS before transmitting a synchronous data frame, divides the constitution of the frame DS to a fixed part DSA and a variable-length part DSB when the number of the subscribed station is below a prescribed number and inserts the part DSA to the head of a matrix which waits to be transmitted before talken incoming for the master station I1. Besides, the frame length of the part DSB is made to be length calculated based on the time difference between the transmitting time (e) of the synchronous data frame and a main synchronizing signal and provided succeedingly to the part DSA. On the other hand, when the number of the subscribed station is over the prescribed number, the frame DS is made to be the variable-length and length based on the time difference between the transmission time of the synchronous data frame and the main synchronizing signal S1 is inserted to the head of the matrix which waits to be transmitted. Then, the synchronous data frame continuing to the frame DS is transmitted synchronously with the signal S1 and the signal synchronization is stably executed by the slave station followingly to the master station I1.

6. 发明专利

JPS63263939A SIGNAL SYNCHRONIZING SYSTEM 失效
公开(公告)号：JPS63263939A
公开(公告)日：1988-10-31
申请号：JP9734987
申请日：1987-04-22
申请人： TOKYO ELECTRIC POWER CO , HITACHI LTD , HITACHI CABLE , MITSUBISHI ELECTRIC CORP , TOSHIBA CORP
发明人： YOSHIDA KAZUYOSHI , MATSUZAWA KUNIO , MAEDA TAKAFUMI , SANO KAZUHIRO , SONE FUMIKI , TAKEDA KAZUHIKO , YOSHIDA TAKASHI , SHIOBARA YASUHISA
摘要： PURPOSE:To avoid the synchronizing error of a slave station from getting larger by setting a flag representing defect of synchronization in a synchronizing data frame when a master station cannot send a synchronizing data frame. CONSTITUTION:A master station 11 for synchronization sends idle data frames DSA and DSB prior to the transmission of a synchronizing data frame D1. The length of the idle data frame DSB is varied in response to the time when the master station 11 receives tokens T1-Tn. Moreover, when the master station 11 cannot send the synchronizing data frame D1 due to delay of token arrival or the like, a flag representing defect of synchronization is set to the data field of the synchronizing data frame D1. Slave stations 12-1n, in detecting the said flag, disregard the synchronizing data frame D1 as the synchronizing signal. Since the signal synchronization of the slave stations is maintained with high accuracy, the stable signal synchronization is attained by using a token passing bus.

7. 发明专利

JPH1080051A METHOD AND DEVICE FOR GROUND-FAULT LINE SELECTION AND PROTECTION RELAYING 失效
公开(公告)号：JPH1080051A
公开(公告)日：1998-03-24
申请号：JP23212496
申请日：1996-09-02
申请人： HITACHI LTD , TOKYO ELECTRIC POWER CO
发明人： IWATANI FUMIO , TAKIGUCHI YUTAKA , SUZUKI YASUTAKA , ICHINOSE NORIFUMI , MAEDA TAKAFUMI
IPC分类号： G01R31/02 , G01R29/16 , H02H3/16 , H02H3/36 , H02H7/22
摘要： PROBLEM TO BE SOLVED: To detect the fault current of a ground-fault by offsetting a zero-phase circulating current with a lesser number of circuit selecting and discriminating elements. SOLUTION: When a one-line ground fault occurs in a system, active component computing circuits 102 and 103 fetch a reference vector Vs the phase of which does not change much and calculate the in-phase and orthogonal components of the difference current J0 between the zero-phase currents of the first and second lines of the system with the vector Vs. Then operators 106 and 107 fetch the variation of the components during the delay time given by memories 104 and 105. Then product circuits 111 and 112, an adder 113, and a divider 114 discriminates the ground-fault by finding the in-phase component with the zero-phase voltage found by means of active component computing circuits 106 and 107, namely, the active component of the variation of the difference current between the zero-phase currents from the in-phase and orthogonal components of the zero-phase voltage found by means of the circuits 108 and 109 with the reference vector Vs and an absolute value found by means of an absolute value circuit 110.

8. 发明专利

JPH0923566A AC OVERVOLTAGE PROTECTIVE RELAY 失效
公开(公告)号：JPH0923566A
公开(公告)日：1997-01-21
申请号：JP18814195
申请日：1995-06-30
申请人： TOKYO ELECTRIC POWER CO , HITACHI LTD , MITSUBISHI ELECTRIC CORP , TOSHIBA CORP
发明人： MAEDA TAKAFUMI , YAMAKAWA HIROSHI , TAKIGUCHI YUTAKA , USUI MASAJI , SAITO HIROSHI , SATO CHIKAO , KUROSAWA YASUHIRO , YAMAURA MITSURU
IPC分类号： H01C7/12 , H02H3/22 , H02H7/24 , H02H9/04
摘要： PURPOSE: To gain the most approximate value of the withstanding strength of a lighting arrester and thereby protect the device by making the precise measurement of energy of the arrester. CONSTITUTION: In an AC overvoltage protective relay that protects an arrester installed in a power system, the following means are installed; a means S1 for inputting a terminal voltage and an energizing current of the arrester, a means S2 for detecting a peak value of the terminal voltage for a specified period of time, a means S3 for calculating an integral value of the energizing current, a means S4 for calculating the absorbed energy of the arrester from the peak value of the terminal voltage and the integral value of the energizing current, a means S5 for determining whether the absorbed energy of the arrester exceeds a specified set value, and output means S6, S7 for making the output based on the result from the means S5.

9. 发明专利

JPH07111726A PROTECTIVE RELAY 失效
公开(公告)号：JPH07111726A
公开(公告)日：1995-04-25
申请号：JP25137693
申请日：1993-10-07
申请人： HITACHI LTD , TOKYO ELECTRIC POWER CO , TOSHIBA CORP , MITSUBISHI ELECTRIC CORP
发明人： KOMATSU SHINJI , SANO KAZUHIRO , SEYA MINORU , WACHI ISAO , MAEDA TAKAFUMI , MATSUDA SHUNICHI , OGAWARA KENJI , SEKIGUCHI KATSUHIKO , NAGASAKI HIROMI , MATSUNAGA KANZO
IPC分类号： H02H3/02 , G06F3/033 , G06F3/041 , H02H3/05
摘要： PURPOSE:To improve the operability by employing a flat display as a setting display panel. CONSTITUTION:A switchboard 1 comprises a protective relay section 2 comprising a digital unit contained therein, a setting display panel 3 mounted on the surface, a flat display 4 provided at a part thereof, and an operational mechanism 5 for controlling the operation thereof. The flat display employs an electroluminescence mechanism or a liquid crystal. The setting display panel 3 has the length and width of about 30cm and the depth of 4-5cm whereas the flat display 4 has the length of about 15cm, the width of about 25cm and the thickness of about 1cm and provided with a touch operation function. This constitution allows interactive setting operation through the flat display thus enhancing the workability and the function.

10. 发明专利

JPH0246127A SYMMETRIC COMPONENT PROTECTIVE RELAY 失效
公开(公告)号：JPH0246127A
公开(公告)日：1990-02-15
申请号：JP19463388
申请日：1988-08-05
申请人： HITACHI LTD , TOKYO ELECTRIC POWER CO
发明人： SANO KAZUHIRO , MATSUI YOSHIAKI , FUJII DAISUKE , OURA YOSHIFUMI , YOSHIDA AKIRA , MAEDA TAKAFUMI
IPC分类号： H02H3/34
摘要： PURPOSE:To improve fault detection sensibility and fault selection reliability by employing reverse phase current and zero phase current as signals for judging fault in a power system. CONSTITUTION:Phase currents Ia, Ib, Ic are fed from a power source 1 to an AD converter 7 and analog values are sampled at same time point (t). Then reverse phase filters 8-11 calculate symmetric component signals of phase currents, i.e., reverse phase currents. A zero phase filter 11 calculates a zero phase current. Thereafter, an a phase (a) judging section 12 judges phase between phase (a) reverse current I2a(t) and zero phase current I0(t), a phase (b) judging section 13 judges phase between phase (b) reverse current I2b(t) and zero phase current I0(t) and phase (c) judging section judges phase between phase (c) reverse current I2c(t) and zero phase current I0(t). The phase judging sections 12-14 judges a phase to be faulty it two input signals are in-phase.

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