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1. 发明专利

JPH10322883A POWER CONVERTER 失效
公开(公告)号：JPH10322883A
公开(公告)日：1998-12-04
申请号：JP6812998
申请日：1998-03-18
申请人： HITACHI LTD
发明人： KUNISADA HIDEAKI , SHIMADA KEIZO , UMETSU HIDEYASU
IPC分类号： G01R31/02 , H02H3/16 , H02H7/122 , H02M7/48 , H02M7/5387
摘要： PROBLEM TO BE SOLVED: To prevent overpotential at the output potential of an inverter by detecting a current flowing between an AC input power supply and the earth or a voltage between them thereby detecting the grounding state of the AC input power supply surely. SOLUTION: When the second phase of a single phase AC power supply 1 is grounded, a ground detection current ieu flows from the first phase of the single phase AC power supply 1 through a second phase loop of a resistor 34, a photocoupler 35, a diode 37, the earth, and the second phase of a single phase AC power supply 1 and a light receiving transistor in the photocoupler 35 is turned on. The ground detection current does not flow into a photocoupler 40 and the light receiving transistor thereof is turned off. Consequently, an overvoltage 15 not applied to a capacitor 29 in case of grounding or nongrounding of the second phase. In case of grounding of the first phase, and an alarm is generated for an apparatus where an inverter is operating in-phase an in synchronism with the AC input power supply and overpotential is prevented by modifying the grounding of the input power supply.

2. 发明专利

JPH10313574A POWER CONVERSION DEVICE AND PHASE-LOCKED CONTROL METHOD THEREFOR 失效
公开(公告)号：JPH10313574A
公开(公告)日：1998-11-24
申请号：JP11690597
申请日：1997-05-07
申请人： HITACHI LTD
发明人： SAKURAI YOSHIMI , KUBO KENJI , KANOUDA TAMAHIKO , UMETSU HIDEYASU , KUNISADA HIDEAKI , SHIMADA KEIZO
IPC分类号： G01R29/18 , H02M1/12 , H02M7/12 , H02M7/155
摘要： PROBLEM TO BE SOLVED: To swiftly synchronize a power conversion device after restoration of a commercial alternating-current power supply. SOLUTION: A phase-locked control circuit 10 exercises control and performs arithmetic operation in order to match the operating frequency of current commands of a power conversion device (converter) 3 which the frequency of an alternating-current power supply. In this phase-locked control circuit 10, the proportional and integral (PI) control operation system of a frequency control circuit 14 is changed by means of a switching signal from a circuit 13 which detects failure and restoration of the alternating-current power supply 1. When an anomaly of the power supply such as instantaneous power failure or power failure occurs, integrating operation is stopped. When the power supply is restored, the integrating operation is restarted. Since the operating frequency does not largely deviate during the period of an anomaly, the synchronization of the power conversion device with the commercial alternating-current power supply is realized in a short time after the power supply is restored. If the power conversion device 3 is a converter, as shown in the figure, operation with the power factor 1 of input current is swiftly achieved. If the power conversion device is an inverter, stable power is immediately supplied to a load.

3. 发明专利

JPH10155276A POWER CONVERSION EQUIPMENT 失效
公开(公告)号：JPH10155276A
公开(公告)日：1998-06-09
申请号：JP30899196
申请日：1996-11-20
申请人： HITACHI LTD , HITACHI ENG CO LTD
发明人： KANOUDA TAMAHIKO , SAKURAI YOSHIMI , KUBO KENJI , UMETSU HIDEYASU , KUNISADA HIDEAKI , SHIMADA KEIZO , NAKANE TAKAYASU
IPC分类号： G01R29/18 , H02M5/458 , H02M7/12 , H02M7/155 , H02M7/219 , H02M7/48
摘要： PROBLEM TO BE SOLVED: To make easier confirmation of power supply connection when installing a power conversion equipment, by providing means for judging the phase sequence and power conduction or power interruption within a power conversion equipment. SOLUTION: A three-phase AC power supply 1 has U, V, and W phases, voltage detection means 2a is located between U and V, voltage detection means 2b is connected between W and V, and outputs from these are connected to a power supply state computing element 4. And the output of Vq computing element 5 possessed by a power supply state computing element 4 is inputted to a state judging means 6 of a power supply and its output is connected to a power conversion equipment 39. If Vq is a constant value, then the phase sequence of the three-phase AC power supply 1 is in the order of U phase →V phase → W phase. If Vq is a sine wave form where the positive and negative wave heights are equal, then the phase sequence is in the order of U phase → W phase → V phase, and if the Vq vibrates in a sine wave form with positive and negative values, with a positive offset, then the U phase or W phase is considered to be grounded and thus handled as a power interruption state.

4. 发明专利

JPH09135542A COMPUTER POWER SUPPLY SYSTEM CONTROLLING SYSTEM 失效
公开(公告)号：JPH09135542A
公开(公告)日：1997-05-20
申请号：JP28701895
申请日：1995-11-06
申请人： HITACHI LTD
发明人： TANIGUCHI YOSHIHIRO , UMETSU HIDEYASU
IPC分类号： G06F1/26 , G06F1/30 , H02J7/34 , H02J9/08
摘要： PROBLEM TO BE SOLVED: To make an unmanned operation possible by using a generator for one power supply out of a plurality of power supplies and a commercial power supply for the other one and incorporating a UPS operation instruction communication means which receives a UPS operation instruction from remote places. SOLUTION: When a commercial power supply is stopped by a power failure while a computer 1 is working, a UPS 2 supplies uninterruptive power to the computer 1 and the computer 1 obtains the information about the power failure of the commercial power supply 5 from a commercial power supply power failure communication means 11 and then a power selection instruction communication means 13 sends out to a switch 3 an instruction to select a generator as a power supply. Furthermore, the UPS 2 has a built-in UPS operation command communication means 21 which receives a UPS operation command from a remote equipment 6 and drives an inverter 22 and a converter 24 to supply power to the computer 1. By this method, a computer power system controlling system can be started up from a remote place and an unmanned operation can be possible.

5. 发明专利

JPH11225482A POWER CONVERTER 失效
公开(公告)号：JPH11225482A
公开(公告)日：1999-08-17
申请号：JP2295298
申请日：1998-02-04
申请人： HITACHI LTD
发明人： YAMAMOTO TAKAHIRO , SHIMADA KEIZO , KUNISADA HIDEAKI , UMETSU HIDEYASU
IPC分类号： H02M1/12 , H02M7/5387
摘要： PROBLEM TO BE SOLVED: To suppress noise to the outside to minimum with a path in which high frequency current flows, simplify a structure and facilitate assembly, by disposing a switching element, a DC capacitor, and an AC filter capacitor in an integral unit so as to form the shortest wiring. SOLUTION: The anode terminals 4 and the cathode terminals 5 of the switching elements S1, S2 of a semiconductor switching unit are connected in parallel to DC capacitors 1, 2, and an AC filter capacitor 3 is connected to the serially-connected part of the DC capacitors 1, 2. By connecting wiring between a high frequency reactor 11 and the unit by the identical bundle, and connecting it to the AC filter capacitor 3 in the unit using the shortest wiring, AC current I4 becomes current with a high frequency component removed, so that high frequency noise to the outside is decreased largely. It is thus possible to close the high frequency noise in the unit, which is effective to reduce radiation noise.

6. 发明专利

JPH10234183A VOLTAGE CONTROLLER FOR VOLTAGE-TYPE PWM INVERTER 失效
公开(公告)号：JPH10234183A
公开(公告)日：1998-09-02
申请号：JP3591397
申请日：1997-02-20
申请人： HITACHI LTD
发明人： KUBO KENJI , KANOUDA TAMAHIKO , SAKURAI YOSHIMI , UMETSU HIDEYASU , KUNISADA HIDEAKI , SHIMADA KEIZO
IPC分类号： H02M7/48
摘要： PROBLEM TO BE SOLVED: To prevent lowering of efficiency, due to the capacitor current of a LC filter in a voltage-type PWM inverter. SOLUTION: The capacitor current of an LC filter 14 is sample-held, in synchronization with the points of the positive and negative maximum amplitudes of a carrier-wave signal 34 for generating the PWM signals of a voltage-type PWM inverter. The instantaneous value of the capacitor current at the time of the present sampling is estimated from the previous sample hold value and the present sample hold value. Using the result of the estimation, capacitor current control is performed. Thus the instantaneous value of the fundamental wave component of the capacitor current can be detected by detecting the capacitor current, in synchronization with the point of the positive and negative maximum amplitudes of a carrier wave. For this reason, an effect, which is equivalent to filtering PWM components by a band rejection filter which is free from delay in detection, is produced.

7. 发明专利

JPH09294381A INPUT/OUTPUT NON-INSULATING POWER CONVERTER 失效
公开(公告)号：JPH09294381A
公开(公告)日：1997-11-11
申请号：JP12907996
申请日：1996-04-25
申请人： HITACHI LTD
发明人： SHIMADA KEIZO , KUNISADA HIDEAKI , UMETSU HIDEYASU
IPC分类号： H02M7/219 , H02M7/12 , H02M7/48 , H02M7/5387
摘要： PROBLEM TO BE SOLVED: To stabilize the potential to the ground of each part of converters by connecting the neutral point of capacitors of an alternating-current input filter, comprising the capacitors and reactors, and the neutral point of capacitors of an alternating-current output filter, comprising reactors and the capacitors, to one line in a direct-current circuit. SOLUTION: Star-connected capacitors 2-4 are placed between an alternatingcurrent power supply 1 and reactors 5-7, and the neutral point of the star-connected capacitors 2-4 is connected to the negative side of a capacitor 20. Star-connected capacitors 38-40 are placed between a load device 41 and reactors 35-37, and the neutral point of the star-connected capacitors 38-40 is connected with the negative side of the capacitor 20. This eliminates fluctuation in voltage at each part of converters caused by the carrier frequency component of a rectifier and the carrier frequency component of an inverter, stabilizes the potential to the ground of each part of these converters, and prevents malfunctions of peripherals.

8. 发明专利

JPH09224376A POWER CONVERSION METHOD AND POWER CONVERTER 失效
公开(公告)号：JPH09224376A
公开(公告)日：1997-08-26
申请号：JP2908396
申请日：1996-02-16
申请人： HITACHI LTD
发明人： SHIMADA KEIZO , UMETSU HIDEYASU , KUNISADA HIDEAKI
IPC分类号： H02M5/458 , H02M7/12 , H02M7/219 , H02M7/48
摘要： PROBLEM TO BE SOLVED: To stabilize a neutral voltage and obtain a small size and easy-to- handle converter by a method wherein the hourly change of a current applied to a neutral phase is detected and the current is so controlled as to be applied to a positive phase side or to a negative phase side in accordance with the hourly change and the hourly change is made to be zero or to be close to zero. SOLUTION: A full-bridge circuit consisting of 3 half-bridge type conversion circuits connected to each other and a common phase to which the second phase of a three-phase AC power supply 1 and the neutral of a DC power supply are connected are provided. The hourly change of a current applied to the common phase which has an influence upon the neutral voltage of two series- connected capacitors 17 and 18 is detected and the on/off duties of the transistors 7 and 8 of the half-bridge type conversion circuit connected to the common phase are changed in accordance with the hourly change. With this constitution, the hourly change of a current applied to the neutral phase is made to be zero or to be close to zero. Therefore, the unbalance in stored charge between the capacitors 17 and 18 can be eliminated.

9. 发明专利

JPS5914293A Temperature controller for induction heating vacuum melting furnace 失效
标题翻译：用于感应加热真空熔融炉的温度控制器
公开(公告)号：JPS5914293A
公开(公告)日：1984-01-25
申请号：JP12207582
申请日：1982-07-15
申请人： Hitachi Ltd , Hitachi Eng Co Ltd
发明人： SATOU MASAKI , UMETSU HIDEYASU
IPC分类号： H05B6/26 , G05D23/19

10. 发明专利

JPS58130795A POWER SOURCE FOR DRIVING AC MOTOR 失效
公开(公告)号：JPS58130795A
公开(公告)日：1983-08-04
申请号：JP1005882
申请日：1982-01-27
申请人： HITACHI LTD , HITACHI ENG CO LTD
发明人： MAEDA TAKEO , UMETSU HIDEYASU , TAKAHASHI NORIYOSHI
IPC分类号： H02P27/06 , H02P21/18 , H02P21/24 , H02P21/34 , H02P23/16 , H02P25/02
摘要： PURPOSE:To again accelerate the speed of a motor in the state likewise the synchronous state by detecting the rotating speed from the induced voltage of the motor and setting the output voltage and frequency of the drive device at the redriving time to values slightly larger than the detected values. CONSTITUTION:When a power interruption is recovered, an arithmetic circuit 24 is completely prepared by the output of a power receiving side detector 8. On the other hand, the voltage component of the induced voltage detector 7 at the motor 6 side is applied to a comparator 12, and the frequency component is applied by a detector 21 to an arithmetic circuit 24. These voltage and frequency are corrected by the circuit 24, are applied through a voltage setter 22 and a frequency setter 23 to a pulse generating and forming circuit 10, and is restarted with an acceleration pattern adapted at the restarting time.

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