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公开(公告)号：JP2001238460A
公开(公告)日：2001-08-31
申请号：JP2000047667
申请日：2000-02-24
Applicant: HITACHI LTD
Inventor： KATO SHUJI , UEDA SHIGETA , IYOTANI RYUJI
IPC: H02M7/12 , H02M1/00 , H02M7/48 , H02M7/483 , H02M7/5387
Abstract: PROBLEM TO BE SOLVED: To provide a power converter comprising a means for enhancing reliability, when a module type switching element is connected in series. SOLUTION: In a power converter, comprising a plurality of self arc suppression type semiconductor switching elements which are connected serially depending on the voltage to be impeded, the self arc suppression type semiconductor switching element is a module type switching element, where a semiconductor chip 3 is mounted on an insulated substrate, and this module type switching element 3 is connected electrically in parallel with a compression type switching element 4, in which a semiconductor chip is held from both sides with package electrodes. When a fault is generated, the compression type switching element 4 connected in parallel with the defective switching element 3 is shorted, and the arm thereof returns to the on state. Thereafter, normal operation can be continued with only the other sound switching element 3 by bypassing the defective switching elements 3.
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公开(公告)号：JP2000308264A
公开(公告)日：2000-11-02
申请号：JP10890699
申请日：1999-04-16
Applicant: HITACHI LTD
Inventor： ICHINOSE MASAYA , FUTAMI MOTOO , UEDA SHIGETA
Abstract: PROBLEM TO BE SOLVED: To detect the individual operation of a power converter by adding a specific order of frequency component to the voltage command value of the power converter, detecting the amplitude value of the specific order of frequency component from a current being outputted from a system, and obtaining the change in the amplitude value. SOLUTION: An n-th order harmonic voltage computing element 13 calculates an n-th order three-phase voltage command value and adds a voltage command value by adders 15d, 15e, and 15f. Then, a PWM computing element 11a outputs a gate pulse based on the voltage command value of the power converter to a power converter 1a. Also, the output of a connection point current detector 2b enables a current amplitude to be calculated by an n-th order harmonic current detector 14a, an individual operation to be detected according to the rapid changes or increase/decrease of the amplitude, and a circuit breaker 19a to be operated. As a result, by deciding the change in system impedance when an individual operation state results according to an n-order current, the individual operation state can be detected and a system can be stopped.
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公开(公告)号：JP2000236656A
公开(公告)日：2000-08-29
申请号：JP3816199
申请日：1999-02-17
Applicant: HITACHI LTD
Inventor： MORI KAZUHISA , UEDA SHIGETA , IYOTANI RYUJI , SAKAI HIROMITSU
Abstract: PROBLEM TO BE SOLVED: To provide a small power converter of a simple structure which employs a self-extinguishing switching element provided with a circuit for self supplying gate driving power stably. SOLUTION: A snubber resistor 41 is connected in series with a power supply voltage dividing resistor 42, which is connected in parallel with a power supply diode 5 and a power supply capacitor 6, and power is supplied to a gate drive circuit 11 via a smoothing circuit 8 comprising a resistor 81 and a capacitor 82. Gate drive power is also supplied from an initial charging resistor 7, when all switching elements are turned off before operating a converter thus realizing a relatively small power converter of simple structure employing a self- extinguishing switching element, where gate drive power can be stabilized through use of snubber energy.
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公开(公告)号：JPH11178217A
公开(公告)日：1999-07-02
申请号：JP33595397
申请日：1997-12-05
Applicant: HITACHI LTD
Inventor： MORITA YUICHIRO , SHIMAMURA KOTARO , TAKAHASHI NOBUTAKA , HOTTA TAKASHI , IMAIE KAZUHIRO , UEDA SHIGETA , BANDO AKIRA , KIDO MITSUYASU
IPC: H04L1/08 , G05B9/03 , G05F1/00 , G06F11/00 , G06F11/07 , G06F11/16 , G06F11/18 , G06F15/16 , G06F15/177 , H02J3/38 , H02M7/48
Abstract: PROBLEM TO BE SOLVED: To enable a system for synchronizing the controllers of multiple system, in which a plurality of systems are operated concurrently in a fixed control period to be operated by one system, even when faults occurs in the plurality of systems. SOLUTION: A synchronous circuit 10a of each system of a system in which controllers provided with the synchronous circuits 10a are multiplexed corrects the control period of its own system, by discriminating the out-of-synchronism of the period signal of its own system from a synchronization reference signal by outputting a period signal which indicates the starting point of a control period from a period signal generating circuit 100 and a synchronization reference signal from a synchronization reference selecting circuit 104 by referring to the period signals of its own system and the other systems. When the synchronization reference signal is not outputted, the synchronous circuit 10a performs such period correction that does not correct the control period of its own system by means of a control period correction circuit 101.
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公开(公告)号：JPH1155859A
公开(公告)日：1999-02-26
申请号：JP22198597
申请日：1997-08-04
Applicant: HITACHI LTD
Inventor： OGAWA TAKESHI , UEDA SHIGETA
Abstract: PROBLEM TO BE SOLVED: To enable repairing a power storing equipment and enable reactive power compensating operation, by continuing operation at the time of trouble of the power storing equipment, in a power converting system wherein a self- exciting power converter and the power storing equipment are combined. SOLUTION: A power converting system for interconnected system consists of the following; a self-exciting type power converter 6 connected with a power system 1, a capacitor 7 and a power storing equipment 9 which are connected in parallel with the DC side of the self-excitation type power converter 6, and a control equipment 4 generating gate pulses which are applied to each self arc-suppressing element of the power converter. A switch 8 is installed between the capacitor and the power storing equipment, and a DC voltage Ec of the power converter is compared with a previously set reference voltage Emin . When the DC voltage Ec drops lower than the reference voltage, the power storing equipment is judged to be trouble, the power storing equipment is cut off by opening the switch, and operation is continued by supplying and absorbing reactive power to and from the power system.
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Patent Agency Ranking
公开(公告)号：JPH10271834A
公开(公告)日：1998-10-09
申请号：JP6673197
申请日：1997-03-19
Applicant: HITACHI LTD , TOKYO ELECTRIC POWER CO
Inventor： SHIMAMURA KOTARO , MORITA YUICHIRO , TAKAHASHI NOBUTAKA , HOTTA TAKASHI , SATO HIROYASU , UEDA SHIGETA , BANDO AKIRA , SUZUKI HIROKAZU , SAKAMOTO KOJI
Abstract: PROBLEM TO BE SOLVED: To enable an equipment controller to return a faulty system to a normal state without stopping equipment even when the controller performs processing in a short computing period, by transferring a plurality of blocks to the faulty system from a normal system over a plurality of computing periods in the order of dependence from the highest order. SOLUTION: When an arithmetic module 131 detects a fault in a computing period (k+1), the module 131 resets a CPU 32O and starts initralization of the control constants of registers in a RAM 316, a memory 412, and a control circuit and initialization of the other elements and the control circuit 414. During the initialization, the module 131 first checks its own hardware for faults in accordance with its own diagnostic program and whether or not a similar fault is detected during a fixed period of time in the past. When a hardware fault is detected or when it is discriminated that an unfixable fault is detected, the module 131 stops the initialization by discriminating that the fault is unfixable. When the cause of the fault is not able to be found, the initialization of such hardware as the register, etc., is started.
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公开(公告)号：JPH09331678A
公开(公告)日：1997-12-22
申请号：JP17066796
申请日：1996-06-10
Applicant: HITACHI LTD
Inventor： SUGIURA YASUYUKI , FUTAMI MOTOO , SATO HIROYASU , UEDA SHIGETA
Abstract: PROBLEM TO BE SOLVED: To continue operation of a power converter by detecting the phase of an accurate and positive system voltage and controlling it safely even if abnormality occurs in an AC system. SOLUTION: The phase (θFi) of an angular speed integrating circuit 134 obtained by integrating a frequency standard signal 132 is used for operating trigonometric function of a Fourier transform operating circuit 127. A positive phase voltage phase (θdi) which is obtained by a positive phase absolute value phase variation operating circuit 128 from Fourier transform is made a phase variation between the phase (θs) of a system voltage and the phase (θFi) of the angular velocity integrating circuit, and a deviation to a zero value 129 is proportional integral-controlled. The output of the proportional integral control 131 is added to the frequency standard signal, and negative feedback is given to the phase of the trigonometric function of the Fourier transform. When some abnormality is found in a three-phase AC power source, the integral term of a phase difference proportional integral circuit is kept constantly at the value before the abnormality, and the integral term is added to the frequency standard signal to detect the phase of the system voltage.
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公开(公告)号：JPH08266058A
公开(公告)日：1996-10-11
申请号：JP8877095
申请日：1995-03-22
Applicant: HITACHI LTD
Inventor： SUGIURA YASUYUKI , UEDA SHIGETA , IMAIE KAZUHIRO , KOSEKI SHOICHIRO
Abstract: PURPOSE: To provide a power converter which performs stable power conversion control even if unbalanced voltage occurs by the abnormality of an AC power system, and stably controls 5 DC power transmitter, a reactive power controller, etc., where the power converter is connected to the power system, thereby enables nonstop operation. CONSTITUTION: This power converter is equipped with a means 119, which gets a voltage and β voltage of two phases by converting the voltage for three phases of a three-phase AC power into that for two phases, a means 120, which finds out sine amplitude of fundamental wave on a coordinate, cosine amplitude of fundamental wave on α coordinate, sine amplitude of fundamental wave on β coordinate, and cosine amplitude of fundamental wave on 3 coordinate by storing the a voltage and βvoltage of two phases separately for each sample over one cycle of AC power, and summing up the products of this value and sine wave and cosine wave tables in order, and finds out the fundamental wave amplitude for positive phases on αcoordinate and the fundamental wave amplitude for positive phase on β coordinate by adding or subtracting these, and a means 121 which detects the phase for positive phase by dividing these amplitude of fundamental waves for positive phase on αcoordinate and the amplitude of fundamental waves for positive phase on β coordinate and operating reverse tangent from the results of division.
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公开(公告)号：JPH06339277A
公开(公告)日：1994-12-06
申请号：JP12674393
申请日：1993-05-28
Applicant: HITACHI LTD
Inventor： NOHARA MIKIYA , UEDA SHIGETA , SUGIURA YASUYUKI , MOTOBE MITSUSACHI
Abstract: PURPOSE:To make a high speed response of a multiplex power converter control possible providing second controllers at every unit power converter and processing in parallel the arithmetic operations of the AC output voltage of the converters respectively having phase difference commanding values. CONSTITUTION:Second controller 3 input AC-DC voltage commanding values Vp* and Vq* of a rotational coordinate system, voltage phase commanding value theta*, and phase difference commanding values delta1*-deltan* with respect to a fundamental-wave voltage on the AC side from a first controller 2 and outputs inverter driving signals PG1-PGNn to a power converter 1. Then the controllers 3 respectively process in parallel the arithmetic operations of the AC output voltage of the converter 1 having the phase difference commanding values delta1*-deltan*. Therefore, a high speed response of the power converter control can be achieved, because the controlled arithmetic operations can be processed at a high speed and the sampling period can be shortened.
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公开(公告)号：JPH06276747A
公开(公告)日：1994-09-30
申请号：JP34326191
申请日：1991-12-25
Applicant: HITACHI LTD , TOKYO ELECTRIC POWER CO
Inventor： UEDA SHIGETA , MOTOBE MITSUSACHI , AIZAWA HIDETOSHI
Abstract: PURPOSE:To obtain a multiplexed self arc-extinguishing type power conversion device, in which a switching angle is selected and higher harmonic content into is minimized as a whole. CONSTITUTION:A power converter is composed of a means 401 computing a fundamental wave component and higher harmonic content regarding all on-off switching angles, where switching angle resolution is considered, means 431, 432, 43m detecting the maximum values of each order higher harmonic content ratio in switching angles, where the fundamental wave component coincides with a value corresponding to command voltage, means 441, 442, 443 selecting higher harmonics, in which each order higher harmonic component is minimized, and a means 41 controlling a digital multiplex equipment by obtained switching angles. Higher harmonic trouble given to an AC system is reduced, the installed capacity of a filter is lowered, and conversion efficiency is improved.
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