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91. 发明专利

JPH02102000A GENERATOR FOR SIMULATOR 失效
公开(公告)号：JPH02102000A
公开(公告)日：1990-04-13
申请号：JP25182388
申请日：1988-10-07
申请人： HITACHI LTD
发明人： NOHARA GOO , GOTO MASUO
IPC分类号： H02J3/00 , H02P9/00 , H02P9/14
摘要： PURPOSE:To represent current accurately upon occurrence of unbalanced fault such as two line shortcircuit fault by correcting the back voltage based on a quadrature-axis current, direct-axis initial transient reactance and quadrature- axis initial transient reactance when an initial transient saliency is represented. CONSTITUTION:Direct-axis initial transient reactance back voltage is corrected based on the quadrature current, direct-axis initial transient reactance and quadrature initial transient reactance of a generator Gen. Since the direct-axis initial transient reactance back voltage is controlled by the quadrature-axis current of the generator Gen, the initial transient phenomenon can be simulated and the armature current overlapped with high frequency current can be simulated. By such an arrangement, unbalanced fault such as two lines shortcircuit fault can be represented accurately.

92. 发明专利

JPH01231625A LOAD CONTROL SYSTEM 失效
公开(公告)号：JPH01231625A
公开(公告)日：1989-09-14
申请号：JP5353588
申请日：1988-03-09
申请人： HITACHI LTD
发明人： NOHARA GOO , GOTO MASUO , AOKI YASUO , NAGAI HAJIME
IPC分类号： H02J3/00
摘要： PURPOSE:To prevent collapse of system due to unstable voltage phenomenon, by detecting the unstable voltage phenomenon and interrupting a predetermined load thereby limiting the total load. CONSTITUTION:Since droppage of voltages VL1, VL2 at the end of loads due to increase of loads L1-L4 is recovered, the voltage may not be recovered for a particular load characteristic even if static capacitors SC1, SC2 are con nected at the ends of the loads. In other words, increment of load determined based on the voltage characteristic of the load exceeds over the increment of the voltage. Consequently, the voltages VL1, VL2 at the ends of the load are collected at potential transformers PT1, PT2 and fed through communication lines T1, T2 to a judging unit J in order to make a judgement. If the variation rate for every predetermined time has a predetermined tendency, e.g., dropping tendency, and the variation rate is lower than a predetermined value, interrup tion commands are fed through communication lines T3, T4 to circuitbreakers CB1, CB2 in order to interrupt a predetermined load thus relieving the overall load and recovering the voltage.

93. 发明专利

JPH01102376A APPARATUS FOR TESTING CONTROL APPARATUS 失效
公开(公告)号：JPH01102376A
公开(公告)日：1989-04-20
申请号：JP25970987
申请日：1987-10-16
申请人： HITACHI LTD
发明人： NOHARA GOO , GOTO MASUO , KANO YASUNOBU
IPC分类号： G01R31/00 , H02H3/05
摘要： PURPOSE:To perform a test in the situation corresponding to the phenomenon of a real system, by imparting arbitrary voltage and a frequency variation pattern and giving the instantaneous value data formed on the basis of the given data to a control apparatus. CONSTITUTION:In a test apparatus TU, voltage V(t) and frequency f(t) to each time are selected from tables T1, T2 storing voltage and the change of frequency to a time and V(t)=V(t)sin{2piintegral f(t)dt} is calculated in a synthesizing part G. This output is given to a control apparatus CU to perform the test of every kind. By this method, the test can be performed in the situation corresponding to the phenomenon of a real system.

94. 发明专利

JPS6488164A FREQUENCY DETECTING DEVICE 失效
公开(公告)号：JPS6488164A
公开(公告)日：1989-04-03
申请号：JP24375887
申请日：1987-09-30
申请人： HITACHI LTD
发明人： NOHARA GOO , GOTO MASUO , KAGEYAMA NOBUHIKO
IPC分类号： G01R23/02 , H02H3/46
摘要： PURPOSE:To take a high-accuracy measurement of frequency even when the frequency varies by employing a rounding-off method for a process of calculating the frequency such as the arithmetic of an instantaneous value at an intermediate point of time according to a sample value when successive sampled values are inverted in sign. CONSTITUTION:The output voltage of a power generator is inputted to a CPU through a voltage transformer PT and an A/D converter. The CPU does not cut away below the decimal place of the instantaneous value a1 at the intermedi ate point of time found from successive sample values a1 and a2 which are inverted in sign, but adds a value half as large as a denominator at the time of division to a numerator and uses the value as a dividend to cut away below the decimal place, thereby performing rounding operation. Further, the zero point and frequency of input data are also calculated similarly to detect the frequency with high accuracy irrelevantly to a sample frequency.

95. 发明专利

JPS63310327A FREQUENCY DETECTOR 失效
公开(公告)号：JPS63310327A
公开(公告)日：1988-12-19
申请号：JP14229187
申请日：1987-06-09
申请人： HITACHI LTD
发明人： KANO YASUNOBU , GOTO MASUO , NOHARA GOO
IPC分类号： G01R23/02 , G01R19/00 , H02H3/46
摘要： PURPOSE:To enable frequency to be properly detected even at the time of system composition fluctuation like generator interruption, by detecting the fluctuation of a physical quantity along with the system composition fluctuation, and by adding its imperfect differential value to a frequency fluctuation detecting value. CONSTITUTION:Based on the waveform period of the terminal voltage of a generator 3, by a frequency detector 7, frequency fluctuation f is detected. Besides, at the time of system composition fluctuation like generator interruption and load fall, the fluctuation( P, I, V, or the like) of a physical quantity for fluctuating synchronized with the momentary fluctuation of frequency is detected by a detector 8. The input of the output of the detector 8 to an imperfect differentiator 1 is provided, and the imperfect differential value( P', V', I', or the like) of the fluctuation of the physical quantity is obtained. Then, by an adder 2, this imperfect differential value is added to the frequency fluctuation f, and corrected signal f' is contrived to be obtained. As a result, the momentary change of the frequency fluctuation f is cancelled, and so a correct detection value is always obtained.

96. 发明专利

JPS63250572A FREQUENCY DETECTOR 失效
公开(公告)号：JPS63250572A
公开(公告)日：1988-10-18
申请号：JP8476087
申请日：1987-04-08
申请人： HITACHI LTD
发明人： NOHARA GOO , GOTO MASUO
IPC分类号： G01R23/02 , H02J3/24
摘要： PURPOSE:To accurately calculate a frequency at a high speed even at the time of variation in frequency by using three-phase alternating currents at the same time and calculating the ratio of the value obtained by adding the products of data which are at sampling intervals by three phases and the sum of squares of respective layers of the three-phase alternating currents at the same time. CONSTITUTION:Frequency detection is performed by using instantaneous values Va, Vb and, Vc of respective phase voltages and storage parts 10, 11, and 12 are stored with voltages of phases (a), (b), and (c) by three samples. Product arithmetic parts 13, 14, and 15 calculate the products of the voltages Va, Vb, and Vc and the outputs of the storage parts 10, 11, and 12 and a sum arithmetic part 16 finds the sum of the outputs of the product arithmetic parts 13, 14, and 15. Square arithmetic parts 20, 21, and 22, on the other hand, finds the squares of the respective voltages Va, Vb, Vc and a sum arithmetic part 23 calculates their sum. A division part 24 finds the ratio of the outputs of the sum arithmetic parts 16 and 23. The calculated value which is thus obtained is proportional to the variation in frequency, so the value is accurate to the variation in frequency; and its denominator contains a term of voltage, so the value is accurate to variation in voltage.

97. 发明专利

JPS63171123A POWER SYSTEM TRANSIENT SIMULATION 失效
公开(公告)号：JPS63171123A
公开(公告)日：1988-07-14
申请号：JP162787
申请日：1987-01-09
申请人： HITACHI LTD
发明人： NOHARA GOO , GOTO MASUO
IPC分类号： H02J3/00

98. 发明专利

JPS6225816A INPUT CIRCUIT FOR PROTECTION RELAY 失效
公开(公告)号：JPS6225816A
公开(公告)日：1987-02-03
申请号：JP16191685
申请日：1985-07-24
申请人： HITACHI LTD
发明人： CHIBA TOMIO , KIDO MITSUYASU , GOTO MASUO , SANO KAZUHIRO
IPC分类号： H02H3/02

99. 发明专利

JPS6032036B2 失效
公开(公告)号：JPS6032036B2
公开(公告)日：1985-07-25
申请号：JP9755675
申请日：1975-08-13
申请人： HITACHI LTD
发明人： GOTO MASUO , TAKAKUSAKI TSUNEHIKO , ISHIKAWA HARUO , ISONO AKIRA , ARAKI MASANOBU , YAMAGUCHI YUKIO
IPC分类号： G05D9/12 , F03B13/06 , F03B15/02 , F03B15/14 , H02J15/00

100. 发明专利

JPS5155936A 失效
公开(公告)号：JPS5155936A
公开(公告)日：1976-05-17
申请号：JP12988474
申请日：1974-11-13
申请人： HITACHI LTD
发明人： GOTO MASUO
IPC分类号： H02J3/06

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