WO2022137291A1 - End of life determination device and power supply device equipped with same - Google Patents

End of life determination device and power supply device equipped with same Download PDF

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Publication number
WO2022137291A1
WO2022137291A1 PCT/JP2020/047722 JP2020047722W WO2022137291A1 WO 2022137291 A1 WO2022137291 A1 WO 2022137291A1 JP 2020047722 W JP2020047722 W JP 2020047722W WO 2022137291 A1 WO2022137291 A1 WO 2022137291A1
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WO
WIPO (PCT)
Prior art keywords
capacitor
current
life
power supply
detection unit
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PCT/JP2020/047722
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French (fr)
Japanese (ja)
Inventor
翔一 阿部
Original Assignee
東芝三菱電機産業システム株式会社
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Application filed by 東芝三菱電機産業システム株式会社 filed Critical 東芝三菱電機産業システム株式会社
Priority to PCT/JP2020/047722 priority Critical patent/WO2022137291A1/en
Publication of WO2022137291A1 publication Critical patent/WO2022137291A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode

Definitions

  • the present invention relates to a life determination device and a power supply device, and more particularly to a life determination device for determining the life of a capacitor connected to an AC terminal of a power converter, and a power supply device including the life determination device.
  • Patent Document 1 discloses a life determination device for determining the life of a capacitor connected to a DC terminal of a power converter.
  • This life determination device includes a current detector that detects the output current of the power converter, a voltage detector that detects the voltage between the terminals of the capacitor, and an initial charge that initially charges the capacitor to a predetermined voltage value by the output current of the power converter.
  • the charging unit, the current integrating unit that integrates the current detected by the current detector during the initial charging period to obtain the current integrated value, and the current integrated value, the predetermined voltage value, and the voltage detector detected before the initial charging.
  • the capacitance estimation unit that calculates the estimated capacitance value of the capacitor based on the voltage between the terminals of the capacitor, and the initial capacitance value of the unused capacitor measured in advance and the estimated capacitance value calculated by the capacitance estimation unit. , It is provided with a life determination unit for determining whether or not the life of the capacitor has reached the end.
  • Patent Document 1 does not describe any life determination device for determining the life of the capacitor connected to the AC terminal of the power converter.
  • a main object of the present invention is a low-cost life determination device capable of determining the life of a capacitor connected to an AC terminal of a power converter during normal operation of the power converter, and a power supply equipped with the same. It is to provide a device.
  • the life determination device is a life determination device for determining the life of a capacitor connected to an AC terminal of a power converter, and includes a current detection unit, a harmonic detection unit, and a determination unit. ..
  • the current detector detects the current flowing through the capacitor when the power converter is operating.
  • the harmonic detection unit detects the harmonic component of the current detected by the current detection unit.
  • the judgment unit compares the harmonic component detected by the harmonic detection unit at the start of use of the capacitor with the harmonic component detected this time by the harmonic detection unit, and the life of the capacitor is reached based on the comparison result. Determine if it has been done.
  • the current flowing through the capacitor connected to the AC terminal of the power converter is detected during the operation of the power converter, the harmonic component of the current is detected, and the capacitor is used at the start of use.
  • the detected harmonic component is compared with the harmonic component detected this time, and it is determined whether or not the life of the capacitor has reached the end of the life of the capacitor based on the comparison result. Therefore, the life of the capacitor connected to the AC terminal of the power converter can be determined during the normal operation of the power converter. Further, since it is not necessary to separately provide a resistor, a switch, etc. for charging the capacitor, the cost of the device can be reduced.
  • FIG. It is a circuit block diagram which shows the structure of the uninterruptible power supply according to Embodiment 1.
  • FIG. It is a circuit diagram which shows the structure of the converter and the inverter shown in FIG.
  • FIG. It is a block diagram which shows the structure of the part which is related to the determination of the life of a capacitor 13 in the control apparatus shown in FIG.
  • FIG. It is a figure which shows the frequency distribution of the capacitor current obtained by the frequency analysis unit shown in FIG.
  • FIG. It is a block diagram which shows the modification example of Embodiment 1.
  • FIG. It is a circuit block diagram which shows the structure of the uninterruptible power supply according to Embodiment 2.
  • FIG. 1 is a circuit block diagram showing a configuration of an uninterruptible power supply device 1 according to the first embodiment.
  • the uninterruptible power supply 1 temporarily converts the three-phase AC power supplied from the commercial AC power supply 21 into DC power, converts the DC power into three-phase AC power, and supplies the DC power to the load 24.
  • FIG. 1 for simplification of drawings and description, only the circuit corresponding to one phase (for example, U phase) of the three phases (U phase, V phase, W phase) is shown.
  • the uninterruptible power supply 1 includes an AC input terminal T1, a bypass input terminal T2, a battery terminal T3, and an AC output terminal T4.
  • the AC input terminal T1 receives AC power of a commercial frequency from the commercial AC power supply 21.
  • the bypass input terminal T2 receives commercial frequency AC power from the bypass AC power supply 22.
  • the bypass AC power supply 22 may be a commercial AC power supply or a generator.
  • the battery terminal T3 is connected to the battery (power storage device) 23.
  • the battery 23 stores DC power.
  • a capacitor may be connected instead of the battery 23.
  • the AC output terminal T4 is connected to the load 24. The load 24 is driven by AC power.
  • the uninterruptible power supply 1 further includes an electromagnetic contactor 2,8,14,17, a current detector 3,11,15, a capacitor 4,9,13, a reactor 5,12, a converter 6, a bidirectional chopper 7, and the like. It includes an inverter 10, a semiconductor switch 16, an operation unit 18, and a control device 19.
  • One terminal of the magnetic contactor 2 is connected to the AC input terminal T1, the other terminal of the magnetic contactor 2 (node N1) is connected to one terminal of the reactor 5, and the other terminal of the reactor 5 is connected to the AC terminal 6a of the converter 6. Be connected.
  • the capacitor 4 is connected between the node N1 and the neutral point NP.
  • the neutral point NP receives, for example, a ground voltage.
  • the magnetic contactor 2 is turned on when the uninterruptible power supply 1 is used, and is turned off, for example, when the uninterruptible power supply 1 is maintained.
  • the instantaneous value of the AC input voltage Vi appearing at the node N1 is detected by the control device 19. Whether or not a power failure has occurred is determined based on the instantaneous value of the AC input voltage Vi.
  • the current detector 3 detects the AC input current Ii flowing through the node N1 and gives a signal If indicating the detected value to the control device 19.
  • the capacitor 4 and the reactor 5 constitute an AC filter F1 to pass AC power of a commercial frequency and prevent a current of a switching frequency generated by the converter 6 from passing to a commercial AC power supply 21.
  • the converter 6 is controlled by the control device 19, and when the AC power is normally supplied from the commercial AC power supply 21 (when the commercial AC power supply 21 is sound), the AC power is converted into DC power and the DC line L1 is used. Output to. When the AC power is not normally supplied from the commercial AC power supply 21 (during a power failure of the commercial AC power supply 21), the operation of the converter 6 is stopped. The output voltage of the converter 6 can be controlled to a desired value.
  • the capacitor 4, the reactor 5, and the converter 6 constitute a forward converter.
  • the capacitor 9 is connected to the DC line L1 and smoothes the voltage of the DC line L1.
  • the instantaneous value of the DC voltage VDC appearing on the DC line L1 is detected by the control device 19.
  • the DC line L1 is connected to the high voltage side node of the bidirectional chopper 7, and the low voltage side node of the bidirectional chopper 7 is connected to the battery terminal T3 via the electromagnetic contactor 8.
  • the magnetic contactor 8 is turned on when the uninterruptible power supply 1 is used, and is turned off when the uninterruptible power supply 1 and the battery 23 are maintained, for example.
  • the instantaneous value of the voltage VB between the terminals of the battery 23 appearing at the battery terminal T3 is detected by the control device 19.
  • the bidirectional chopper 7 is controlled by the control device 19, and when the commercial AC power supply 21 is sound, the DC power generated by the converter 6 is stored in the battery 23, and when the commercial AC power supply 21 fails, the DC power of the battery 23 is DC. It is supplied to the inverter 10 via the line L1.
  • the bidirectional chopper 7 When the bidirectional chopper 7 stores DC power in the battery 23, the bidirectional chopper 7 steps down the DC voltage VDC of the DC line L1 and supplies it to the battery 23. Further, when the bidirectional chopper 7 supplies the DC power of the battery 23 to the inverter 10, the bidirectional chopper 7 boosts the voltage VB between the terminals of the battery 23 and outputs the DC power to the DC line L1.
  • the DC line L1 is connected to the input node of the inverter 10.
  • the inverter 10 is controlled by the control device 19 and converts the DC power supplied from the converter 6 or the bidirectional chopper 7 via the DC line L1 into commercial frequency AC power and outputs it. That is, the inverter 10 converts the DC power supplied from the converter 6 via the DC line L1 into AC power when the commercial AC power supply 21 is sound, and the bidirectional chopper 7 from the battery 23 when the commercial AC power supply 21 fails. Converts the DC power supplied via the AC power into AC power.
  • the output voltage of the inverter 10 can be controlled to a desired value.
  • the AC terminal 10a of the inverter 10 is connected to one terminal of the reactor 12, the other terminal (node N2) of the reactor 12 is connected to one terminal of the magnetic contactor 14, and the other terminal (node N3) of the magnetic contactor 14 is AC. It is connected to the output terminal T4.
  • the capacitor 13 is connected between the node N2 and the neutral point NP.
  • the neutral point NP receives, for example, a ground voltage.
  • the current detector 11 detects an instantaneous value of the output current Io of the inverter 10 and gives a signal Iof indicating the detected value to the control device 19.
  • the instantaneous value of the AC output voltage Vo appearing at the node N2 is detected by the control device 19.
  • the reactor 12 and the capacitor 13 constitute an AC filter F2, and the AC power of the commercial frequency generated by the inverter 10 is passed through the AC output terminal T4, and the current of the switching frequency generated by the inverter 10 is passed through the AC output terminal T4. Prevent it from happening.
  • the inverter 10, the reactor 12, and the capacitor 13 constitute an inverse converter.
  • the electromagnetic contactor 14 is controlled by the control device 19 and is turned on in the inverter power supply mode in which the AC power generated by the inverter 10 is supplied to the load 24.
  • the bypass power supply supplies the AC power from the bypass AC power supply 22 to the load 24. It is turned off in mode.
  • the current detector 15 detects an instantaneous value of the load current IL flowing between the node N3 and the AC output terminal T4, and gives a signal ILf indicating the detected value to the control device 19.
  • the semiconductor switch 16 includes a pair of thyristors connected in antiparallel to each other, and is connected between the bypass input terminal T2 and the node N3.
  • the magnetic contactor 17 is connected in parallel to the semiconductor switch 16.
  • the semiconductor switch 16 is controlled by the control device 19, is normally turned off, and is turned on instantly when the inverter 10 fails, and supplies AC power from the bypass AC power supply 22 to the load 24.
  • the semiconductor switch 16 is turned off after a predetermined time has elapsed since it was turned on.
  • the electromagnetic contactor 17 is turned off in the inverter power supply mode in which the AC power generated by the inverter 10 is supplied to the load 24, and is turned on in the bypass power supply mode in which the AC power from the bypass AC power supply 22 is supplied to the load 24.
  • the electromagnetic contactor 17 is turned on when the inverter 10 fails, and supplies AC power from the bypass AC power supply 22 to the load 24. That is, when the inverter 10 fails, the semiconductor switch 16 is instantly turned on for a predetermined time and the electromagnetic contactor 17 is turned on. This is to prevent the semiconductor switch 16 from being overheated and damaged.
  • the operation unit 18 includes a plurality of buttons operated by the user of the uninterruptible power supply 1, an image display unit that displays various information, and the like. By operating the operation unit 18, the user can turn on and off the power of the uninterruptible power supply 1, select either the bypass power supply mode or the inverter power supply mode, or use a new capacitor 13. It is possible to enter the fact that is set.
  • the operation unit 18 When the operation unit 18 is input to the effect that a new capacitor 13 is set and the inverter power supply mode is selected, the operation unit 18 outputs a signal ST instructing the start of the life determination of the capacitor 13 to the control device 19.
  • the control device 19 is a non-disruptive power supply based on a signal from the operation unit 18, AC input voltage Vi, AC input current Ii, DC voltage VDC, battery voltage VB, AC output current Io, AC output voltage Vo, load current IL, and the like. Controls the entire device 1. That is, the control device 19 detects whether or not a power failure has occurred based on the detected value of the AC input voltage Vi, and controls the converter 6 and the inverter 10 in synchronization with the phase of the AC input voltage Vi.
  • control device 19 controls the converter 6 based on the AC input voltage Vi, the AC input current Ii, and the DC voltage VDC.
  • the control device 19 controls the converter 6 so that the DC voltage VDC becomes a desired target voltage VDCT when the commercial AC power supply 21 is sound, and stops the operation of the converter 6 when the commercial AC power supply 21 fails.
  • control device 19 controls the bidirectional chopper 7 based on the DC voltage VDC and the battery voltage VB.
  • the control device 19 controls the bidirectional chopper 7 so that the battery voltage VB becomes the desired target battery voltage VBT when the commercial AC power supply 21 is sound, and the DC voltage VDC is the desired target when the commercial AC power supply 21 fails.
  • the bidirectional chopper 7 is controlled so that the voltage is VDCT.
  • control device 19 controls the inverter 10 so that the AC output voltage Vo becomes a desired target voltage VoT based on the AC output current Io and the AC output voltage Vo. Further, the control device 19 constantly monitors the load current IL, and when the load current IL becomes excessive, for example, the electromagnetic contactors 14 and 17 and the semiconductor switch 16 are turned off to protect the uninterruptible power supply device 1.
  • the control device 19 compares the harmonic component detected at the start of use of the capacitor 13 with the harmonic component detected this time, determines whether or not the life of the capacitor 13 has expired based on the comparison result, and determines whether the capacitor 13 has reached the end of its life.
  • the user of the uninterruptible power supply device 1 is notified to that effect by using sound, light, an image, or the like. The method of determining the life of the capacitor 13 will be described in detail later.
  • the AC power supplied from the commercial AC power supply 21 is converted into DC power by the converter 6.
  • This DC power is stored in the battery 23 by the bidirectional chopper 7 and converted into AC power by the inverter 10.
  • This AC power is supplied to the load 24 via the AC filter F2.
  • the load 24 is operated by AC power.
  • the impedance of the capacitor 13 includes a capacitance component and a resistance component. As the capacitor 13 deteriorates, the resistance component of the impedance of the capacitor 13 increases, and the harmonic component of the current flowing through the capacitor 13 decreases.
  • the control device 19 detects the harmonic component of the current Ic flowing through the capacitor 13 based on the output signals If and ILf of the current detectors 11 and 15 at predetermined time intervals, and the harmonic component detected at the start of use of the capacitor 13. Is compared with the harmonic component detected this time, and based on the comparison result, it is determined whether or not the life of the capacitor 13 has reached the end. When it is determined that the life of the capacitor 13 has reached the end of its life, the user of the uninterruptible power supply 1 is notified to that effect.
  • the user of the uninterruptible power supply 1 When it is notified that the life of the capacitor 13 has expired, the user of the uninterruptible power supply 1 operates the operation unit 18 to select the bypass power supply mode to turn on the magnetic contactor 17 and make electromagnetic contact.
  • the vessels 2, 8 and 14 are turned off, and the operation of the converter 6, the bidirectional chopper 7, and the inverter 10 is stopped.
  • the load 24 is driven by AC power supplied from the bypass AC power supply 22 via the electromagnetic contactor 17.
  • the user of the uninterruptible power supply 1 replaces the capacitor 13 with a new one.
  • the user operates the operation unit 18 to input that a new capacitor 13 has been set, and selects the inverter power supply mode.
  • the converter 6, the bidirectional chopper 7, and the inverter 10 are operated, the magnetic contactors 2, 8 and 14 are turned on, the magnetic contactor 17 is turned off, and the AC filter F2 and the electromagnetic contactor 14 are removed from the inverter 10.
  • AC power is supplied to the load 24 via the load 24. Further, the life of the capacitor 13 is determined every predetermined time.
  • the operation of the converter 6 is stopped, and the DC power of the battery 23 is supplied to the inverter 10 by the bidirectional chopper 7.
  • the inverter 10 converts the DC power from the bidirectional chopper 7 into AC power and supplies it to the load 24. Therefore, the operation of the load 24 can be continued while the DC power is stored in the battery 23.
  • the semiconductor switch 16 is instantly turned on, the magnetic contactor 14 is turned off, and the magnetic contactor 17 is turned on.
  • the AC power from the bypass AC power supply 22 is supplied to the load 24 via the semiconductor switch 16 and the electromagnetic contactor 17, and the operation of the load 24 is continued.
  • the semiconductor switch 16 is turned off to prevent the semiconductor switch 16 from being overheated and damaged.
  • FIG. 2 is a circuit diagram showing the configurations of the converter 6 and the inverter 10 shown in FIG. In FIG. 1, only the portion related to one phase of the three-phase AC voltage is shown, but in FIG. 2, the portion related to the three phases is shown.
  • the converter 6 includes IGBTs (Insulated Gate Bipolar Transistors) Q1 to Q6 and diodes D1 to D6.
  • the IGBT constitutes a switching element.
  • the collectors of IGBT Q1 to Q3 are both connected to the DC line L1, and their emitters are connected to the AC terminals 6a, 6b, 6c, respectively.
  • the collectors of IGBT Q4 to Q6 are connected to the AC terminals 6a, 6b, 6c, respectively, and their emitters are both connected to the DC line L2.
  • Diodes D1 to D6 are connected to IGBT Q1 to Q6 in antiparallel, respectively.
  • the AC terminals 6a, 6b, 6c receive a three-phase AC voltage supplied from the commercial AC power supply 21 via three sets of electromagnetic contactors 2 and an AC filter F1 (FIG. 1).
  • the three-phase AC voltage supplied to the AC terminals 6a to 6c is three-phase full-wave rectified by the diodes D1 to D6, converted into a DC voltage VDC, and applied between the terminals of the capacitor 9.
  • the IGBT Q1 and Q4 are controlled by the gate signals Au and Bu, respectively
  • the IGBT Q2 and Q5 are controlled by the gate signals Av and Bv, respectively
  • the IGBT Q3 and Q6 are controlled by the gate signals Aw and Bw, respectively.
  • the gate signals Bu, Bv, and Bw are inverted signals of the gate signals Au, Av, and Aw, respectively.
  • IGBTQ1 to Q3 are turned on when the gate signals Au, Av, and Aw are set to the "H” level, and turned off when the gate signals Au, Av, and Aw are set to the “L” level, respectively.
  • IGBTQ4 to Q6 are turned on when the gate signals Bu, Bv, and Bw are set to the "H” level, and turned off when the gate signals Bu, Bv, and Bw are set to the "L” level, respectively.
  • Each of the gate signals Au, Bu, Av, Bv, Aw, and Bw is a pulse signal sequence and is a PWM (Pulse Width Modulation) signal having a switching frequency (for example, 6 KHz).
  • the phases of the gate signals Au and Bu, the phases of the gate signals Av and Bv, and the phases of the gate signals Aw and Bw are deviated by 120 degrees.
  • the gate signals Au, Bu, Av, Bv, Aw, Bw are generated by the control device 19.
  • Each of IGBT Q1 to Q6 is turned on and off at the switching frequency.
  • the voltage between the terminals of the capacitor 9 is adjusted by turning each of the IGBT Q1 to Q6 on and off at a predetermined timing by the gate signals Au, Bu, Av, Bv, Aw, and Bw, and adjusting the on time of each of the IGBT Q1 to Q6. It is possible to convert the VDC into a commercial frequency three-phase AC voltage and output it to the AC terminals 6a to 6c.
  • the three-phase AC voltage output from the converter 6 includes a fundamental wave component of a commercial frequency and a harmonic component.
  • the harmonic component includes a high frequency component that is several times the natural number of the switching frequency.
  • the AC filter F1 passes the fundamental wave component of the commercial frequency and cuts off the harmonic component.
  • the inverter 10 has the same configuration as the converter 6, and includes the IGBT Q11 to Q16 and the diodes D11 to D16.
  • the IGBT constitutes a switching element.
  • the collectors of IGBT Q11 to Q13 are both connected to the DC line L1, and their emitters are connected to the AC terminals 10a, 10b, and 10c, respectively.
  • the collectors of IGBT Q14 to Q16 are connected to the AC terminals 10a, 10b, and 10c, respectively, and their emitters are both connected to the DC line L2.
  • the diodes D11 to D16 are connected to the IGBT Q11 to Q16 in antiparallel, respectively.
  • the IGBT Q11 and Q14 are controlled by the gate signals Xu and Yu, respectively, the IGBT Q12 and Q15 are controlled by the gate signals Xv and Yv, respectively, and the IGBT Q13 and Q16 are controlled by the gate signals Xw and Yw, respectively.
  • the gate signals Yu, Yv, and Yw are inverted signals of the gate signals Xu, Xv, and Xw, respectively.
  • IGBTQ11 to Q13 are turned on when the gate signals Xu, Xv, Xw are set to the "H” level, and turned off when the gate signals Xu, Xv, Xw are set to the "L” level, respectively.
  • IGBTQ14 to Q16 are turned on when the gate signals Yu, Yv, and Yw are set to the "H” level, and turned off when the gate signals Yu, Yv, and Yw are set to the "L” level, respectively.
  • Each of the gate signals Xu, Yu, Xv, Yv, Xw, and Yw is a pulse signal sequence and is a PWM signal having a switching frequency (for example, 6 KHz).
  • the phases of the gate signals Xu and Yu, the phases of the gate signals Xv and Yv, and the phases of the gate signals Xw and Yw are deviated by 120 degrees.
  • the gate signals Xu, Yu, Xv, Yv, Xw, Yw are generated by the control device 19.
  • Each of IGBT Q11 to Q16 is turned on and off at the switching frequency.
  • the voltage between the terminals of the capacitor 9 is adjusted by turning each of the IGBT Q11 to Q16 on and off at a predetermined timing by the gate signals Xu, Yu, Xv, Yv, Xw, and Yw and adjusting the on time of each of the IGBT Q11 to Q16. It is possible to convert the VDC into a commercial frequency three-phase AC voltage and output it to the AC terminals 10a, 10b, and 10c.
  • the three-phase AC voltage generated by the inverter 10 is supplied to the load 24 via the three sets of AC filters F2 and the electromagnetic contactor 14.
  • the three-phase AC voltage output from the inverter 10 includes a fundamental wave component of a commercial frequency and a harmonic component.
  • the harmonic component includes a high frequency component that is several times the natural number of the switching frequency.
  • the AC filter F2 passes the fundamental wave component of the commercial frequency and cuts off the harmonic component.
  • the capacitor 13 gradually deteriorates according to the usage time of the capacitor 13.
  • the resistance component of the capacitor 13 increases, it becomes difficult for the harmonic component to flow through the capacitor 13, and the harmonic component passing through the AC filter F2 increases. Since this harmonic component adversely affects the load 24, it is necessary to replace the capacitor 13 with a new one when the life of the capacitor 13 is reached.
  • the current Ic flowing through the capacitor 13 is obtained based on the detection results of the current detectors 11 and 15 during the normal operation of the inverter 10, and the harmonic component of the current Ic is detected. Then, the harmonic component detected at the start of use of the capacitor 13 is compared with the harmonic component detected this time, and based on the comparison result, it is determined whether or not the life of the capacitor 13 has reached, and the life of the capacitor 13 is reached. If it is determined that it has arrived, the user of the uninterruptible power supply device 1 is notified to that effect.
  • FIG. 3 is a block diagram showing a part of the control device 19 related to the determination of the life of the capacitor 13.
  • the control device 19 includes a calculation unit 30, a timer 31, a frequency analysis unit 32, an amplitude detection unit 33, a storage unit 34, a determination unit 35, and a notification unit 36.
  • the current detectors 11 and 15, the operation unit 18, and the control device 19 constitute a life determination device for determining the life of the capacitor 13.
  • the calculation unit 30 uses the instantaneous value of the output current Io of the inverter 10 indicated by the output signal Iof of the current detector 11 (FIG. 1) to the load current IL indicated by the output signal ILf of the current detector 15 (FIG. 1). The instantaneous value is subtracted to obtain the instantaneous value of the current Ic flowing through the capacitor 13.
  • FIG. 4 is a time chart for explaining the operation of the calculation unit 30.
  • (A) shows the waveforms of the three-phase AC voltages Vu, Vv, and Vw output from the inverter 10 and passed through the three AC filters F2, and (B) is the three currents output from the inverter 10.
  • the waveforms of the three-phase alternating currents Iu, Iv, and Iw detected by the detector 11 are shown.
  • FIGS. 1 and 3 only the portion corresponding to the U phase of the U phase, the V phase, and the W phase is shown for the sake of simplification of drawings and explanations.
  • the AC voltage Vo (FIG. 1) of the node N2 corresponds to the U-phase AC voltage Vu.
  • the AC output current Io of the inverter 10 indicated by the output signal If (FIG. 1) of the current detector 11 corresponds to the U-phase AC current Iu.
  • FIG. 3 shows the waveform of the current Ic flowing through the capacitor 13 calculated by the calculation unit 30 (FIG. 3).
  • each of the three-phase AC voltages Vu (that is, Vo), Vv, and Vw generated by the inverter 10 and the AC filter F2 changes in a sine wave shape at a commercial frequency.
  • the phases of the three-phase AC voltages Vu (that is, Vo), Vv, and Vw are shifted by 120 degrees.
  • each of the three-phase alternating currents Iu (that is, Io), Iv, and Iw output from the inverter 10 basically changes in a sinusoidal shape at a commercial frequency.
  • the phases of the three-phase alternating currents Iu (that is, Io), Iv, and Iw are shifted by 120 degrees.
  • Each of the three-phase alternating currents Iu (ie, Io), Iv, and Iw contains a fundamental wave component of a commercial frequency and a harmonic component having a frequency that is a natural number multiple of the switching frequency.
  • the harmonic component is superimposed on the fundamental wave component.
  • the capacitor current IcD actually detected by the separately provided current detector basically changes in a sinusoidal shape at a commercial frequency.
  • the phase of the capacitor current IcD is 90 degrees ahead of the phase of the AC voltage Vu (ie, Vo).
  • the capacitor current IcD includes a fundamental wave component of a commercial frequency and a harmonic component having a frequency that is a natural number multiple of the switching frequency.
  • the harmonic component is superimposed on the fundamental wave component.
  • the amplitude of the harmonic component of the current IcD after the deterioration of the capacitor 13 is smaller than the amplitude of the harmonic component of the current IcD before the deterioration of the capacitor 13. This corresponds to the fact that when the capacitor 13 deteriorates, the resistance component of the capacitor 13 increases, and it becomes difficult for the harmonic current to flow through the capacitor 13.
  • the load current IL basically changes in a sinusoidal shape at a commercial frequency.
  • the phase of the load current IL is the same as the phase of the AC voltage Vu (that is, Vo).
  • the load current IL does not contain a harmonic component.
  • the load current IL contains some harmonic components.
  • the waveform of the capacitor current Ic calculated by the calculation unit 30 is the waveform of the capacitor current IcD actually detected by the current detector (FIG. 4 (C)). Is consistent with. Therefore, in the first embodiment, it is not necessary to separately provide a current detector for detecting the current Ic flowing through the capacitor 13, so that the device configuration can be simplified and the cost of the device can be reduced.
  • the operation unit 18 (FIG. 1) is instructed to execute the inverter power supply mode.
  • the signal ST is output after a predetermined time required for stabilizing the operation of the device has elapsed.
  • the timer 31 is reset in response to the signal ST from the operation unit 18, measures the normal operation time TD of the inverter 10, and outputs a signal TDf indicating the measured time TD. Every time the measured time TD reaches a predetermined time, the measured time TD is reset to 0 seconds.
  • the normal operation time TD of the inverter 10 is the time during which the AC output power of the inverter 10 is supplied to the load 24 via the AC filter F2 and the electromagnetic contactor 14. At this time, the harmonic component flows through the capacitor 13, and the capacitor 13 gradually deteriorates.
  • the frequency analysis unit 32 captures the waveform of the current Ic obtained by the calculation unit 30 every time the time TD indicated by the output signal TDf of the timer 31 is reset to 0 seconds, and fast Fouriers the waveform of the captured current Ic.
  • the frequency distribution of the current Ic is obtained by performing the conversion.
  • FIG. 5 is a diagram showing the frequency distribution of the current Ic flowing through the capacitor 13.
  • (A) shows the frequency distribution of the current Ic before the deterioration of the capacitor 13 (that is, at the start of use), and (B) shows the frequency distribution of the current Ic after the deterioration of the capacitor 13.
  • the current Ic flowing through the capacitor 13 includes a fundamental wave component of a commercial frequency (50 Hz) and a harmonic component.
  • the harmonic components are mainly a high frequency component (first current) having a frequency N times (for example, 1 times) the switching frequency (6 KHz) and a high frequency component having a frequency M times (for example, 2 times) the switching frequency (for example, 2 times). Second current) and included.
  • N is a natural number and M is a natural number different from N.
  • the amplitude of the harmonic component after the deterioration of the capacitor 13 is smaller than the amplitude of the harmonic component before the deterioration of the capacitor 13. This corresponds to the fact that the resistance component of the capacitor 13 increases and the harmonic component flowing through the capacitor 13 decreases as the deterioration of the capacitor 13 progresses.
  • the amplitude detection unit 33 has an amplitude A1 of a current having a frequency of 1 times the switching frequency (6KHz) and a switching frequency of 2 based on the frequency distribution obtained by the frequency analysis unit 32.
  • the amplitude A2 of the current having a double frequency (12 KHz) is detected.
  • the storage unit 34 stores the amplitudes A1 and A2 detected by the amplitude detection unit 33 as initial amplitude values A1n and A2n, respectively, in response to the signal ST from the operation unit 18.
  • the determination unit 35 compares the initial amplitude values A1n and A2n stored in the storage unit 34 with the amplitudes A1 and A2 detected this time by the amplitude detection unit 33, and based on the comparison result, the life of the capacitor 13 has come to an end. It is determined whether or not it has been done, and a signal ⁇ 35 indicating the determination result is output.
  • the signal ⁇ 35 is set to the “L” level of the deactivation level.
  • the signal ⁇ 35 is set to the “H” level of the activation level.
  • the difference ⁇ A1 A1n ⁇ A1 between the initial amplitude value A1n (first amplitude) and the amplitude A1 (second amplitude) exceeds the upper limit value A1H, and the initial amplitude value A2n (first amplitude).
  • the difference ⁇ A2 A2n ⁇ A2n between (amplitude of 3) and amplitude A2 (fourth amplitude) exceeds the upper limit value A2H
  • the signal ⁇ 35 is set to the activation level “ Set to H "level.
  • the determination unit 35 sets the signal ⁇ 35 to the “L” level of the deactivation level.
  • the notification unit 36 When the signal ⁇ 35 is set to the activation level “H” level, the notification unit 36 indicates that the life of the capacitor 13 has reached the end of the life of the capacitor 13 by using light, sound, an image, or the like to notify the user of the uninterruptible power supply 1. Notify to.
  • the life determination operation of the capacitor 13 in the uninterruptible power supply 1 will be described.
  • the bypass feeding mode is selected and a new capacitor 13 is set.
  • the operation unit 18 is operated by the user of the uninterruptible power supply 1, it is input that a new capacitor 13 is set, and the inverter power supply mode is selected, the electromagnetic contactors 2, 8 and 14 are turned on and the converter is converted. 6.
  • the operation of the bidirectional chopper 7 and the inverter 10 is started, and the electromagnetic contactor 17 is turned off.
  • the AC power supplied from the commercial AC power supply 21 is converted into DC power by the converter 6, the DC power is stored in the battery 23 by the bidirectional chopper 7, and is converted into AC power by the inverter 10 and supplied to the load 24.
  • the output current Io of the inverter 10 is detected by the current detector 11, and the load current IL is detected by the current detector 15.
  • the calculation unit 30 (FIG. 3) subtracts the load current IL from the output current Io of the inverter 10 to calculate the current Ic flowing through the capacitor 13.
  • the signal ST is output from the operation unit 18 after a predetermined time required for stabilizing the operation of the device has elapsed.
  • the timer 31 is reset in response to the signal ST, and the operation time TD of the inverter 10 is reset to 0 seconds, and then the measurement of the operation time TD is started. Every time the operation time TD of the inverter 10 reaches a predetermined time, the operation time TD of the inverter 10 is reset to 0 seconds.
  • the waveform of the capacitor current Ic calculated by the calculation unit 30 is taken into the frequency analysis unit 32, and the frequency distribution of the capacitor current Ic is obtained. From the frequency distribution of the capacitor current Ic, the amplitude detection unit 33 determines that the amplitude A1 of the current having a frequency of 1 times the switching frequency (6 KHz) and the amplitude A2 of the current having a frequency twice the switching frequency (12 KHz). Detected.
  • the storage unit 34 stores the amplitudes A1 and A2 detected by the amplitude detection unit 33 as initial amplitude values A1n and A2n, respectively, in response to the signal ST from the operation unit 18. Every time the operating time TD of the inverter 10 reaches a predetermined time, the frequency analysis unit 32 obtains the frequency distribution of the capacitor current Ic, and the amplitude detection unit 33 detects the amplitudes A1 and A2.
  • the amplitudes A1 and A2 detected this time by the amplitude detection unit 33 and the initial amplitude values A1n and A2n stored in the storage unit 34 are compared by the determination unit 35, and the life of the capacitor 13 has come to an end based on the comparison result. Whether or not it is determined.
  • the determination unit 35 determines that the life of the capacitor 13 has reached the end, the notification unit 36 notifies the user of the uninterruptible power supply device 1 to that effect.
  • the user selects the bypass power supply mode using the operation unit 18.
  • the magnetic contactors 2, 8 and 14 are turned off, the magnetic contactor 17 is turned on, AC power is supplied from the bypass AC power supply 22 to the load 24 via the magnetic contactor 17, and the operation of the load 24 is continued. Will be done. Further, the operation of the converter 6, the bidirectional chopper 7, and the inverter 10 is stopped.
  • the user replaces the capacitor 13 that has reached the end of its life with a new capacitor 13, and then operates the operation unit 18 to instruct that the new capacitor 13 is set and that the inverter power supply mode is executed.
  • the magnetic contactors 2, 8 and 14 are turned on, the converter 6, the bidirectional chopper 7 and the inverter 10 are started to operate, the magnetic contactor 17 is turned off, and the load 24 is powered by the AC power from the inverter 10. Be driven. Further, the determination of the life of the new capacitor 13 is started.
  • the current Ic flowing through the capacitor 13 connected to the AC terminal 10a of the inverter 10 is detected during normal operation of the inverter 10, and the harmonic component of the current Ic is detected.
  • the harmonic component detected at the start of use of the capacitor is compared with the harmonic component detected this time, and it is determined whether or not the life of the capacitor 13 has reached the end of the life of the capacitor 13 based on the comparison result. Therefore, the life of the capacitor 13 can be determined while the inverter 10 is normally operated. Further, as compared with Patent Document 1, since it is not necessary to separately provide a resistor, a switch, or the like for charging the capacitor 13, the cost of the device can be reduced.
  • FIG. 6 is a block diagram showing a modified example of the first embodiment, and is a diagram to be compared with FIG. With reference to FIG. 6, the difference between this modification and the first embodiment is that the determination unit 35 is replaced with the determination unit 35A.
  • the determination unit 35A when the ratio A1 / A1n of the amplitude value A1 and the initial amplitude value A1n is lower than the lower limit value A1L and the ratio A2 / A2n of the amplitude value A2 and the initial amplitude value A2n is lower than the lower limit value A2L.
  • the signal ⁇ 35 is set to the “H” level of the activation level. Since other configurations and operations are the same as those in the first embodiment, the description thereof will not be repeated. Even in this modified example, the same effect as that of the first embodiment can be obtained.
  • the third condition (A1 / A1n ⁇ A1L) in which the ratio A1 / A1n of the amplitude value A1 and the initial amplitude value A1n is lower than the lower limit value A1L, and the amplitude value A2 and the initial amplitude value A2n.
  • the fourth condition (A2 / A2n ⁇ A2L) in which the ratio A2 / A2n is lower than the lower limit value A2L are satisfied, it is determined that the life of the capacitor 13 has come to an end, but this is limited to this. However, it may be determined that the life of the capacitor 13 has reached the end when any one of the third and fourth conditions is satisfied.
  • the converter 6 converts the terminal voltage VDC of the capacitor 9 into an AC voltage and outputs the voltage to the commercial AC power supply 21 via the AC filter F1.
  • a large number of loads (not shown) are connected to the commercial AC power supply 21 (that is, the power system).
  • the converter 6 and the AC filter F1 and the inverter 10 and the AC filter F2 have the same configuration.
  • the capacitor 4 included in the AC filter F1 also deteriorates in the same manner as the capacitor 13. Therefore, in the second embodiment, the life of the capacitor 4 is determined.
  • FIG. 7 is a circuit block diagram showing the configuration of the uninterruptible power supply device 1A according to the second embodiment, and is a diagram to be compared with FIG. 1.
  • the uninterruptible power supply 1A differs from the uninterruptible power supply 1 of the first embodiment in that the current detector 40 is added and the control device 19 is replaced by the control device 19A. be.
  • the current detector 40 detects the input current (that is, the current flowing through the reactor 5) Iic of the converter 6 and outputs the signal Iicf indicating the detected value.
  • the control device 19A subtracts the AC input current Ii indicated by the output signal If of the current detector 3 from the input current Iic of the converter 6 indicated by the output signal Iicf of the current detector 40 to obtain the capacitor 4.
  • the current IcA Iic-Ii flowing through the current IcA is obtained, and the harmonic component of the current IcA is detected.
  • control device 19A compares the harmonic component detected at the start of use of the capacitor 4 with the harmonic component detected this time, determines whether or not the life of the capacitor 4 has expired based on the comparison result, and determines whether the capacitor 4 has reached the end of its life.
  • the user of the uninterruptible power supply device 1A is notified by using sound, light, an image, or the like.
  • FIG. 8 is a block diagram showing a portion of the control device 19A related to the determination of the life of the capacitor 4, and is a diagram to be compared with FIG.
  • the control device 19A includes a calculation unit 30, a timer 31, a frequency analysis unit 32, an amplitude detection unit 33, a storage unit 34, a determination unit 35, and a notification unit 36, similarly to the control device 19. ..
  • the current detectors 3 and 40, the operation unit 18, and the control device 19A constitute a life determination device for determining the life of the capacitor 4.
  • the calculation unit 30 subtracts the instantaneous value of the AC input current Ii indicated by the output signal If of the current detector 3 from the instantaneous value of the input current Iic of the converter 6 indicated by the output signal Iicf of the current detector 40. The instantaneous value of the current IcA flowing through the capacitor 4 is obtained.
  • the operation unit 18 When the user of the uninterruptible power supply 1 inputs that a new capacitor 4 has been set and is instructed to execute the inverter power supply mode, the operation unit 18 has a predetermined time required for stabilizing the operation of the device. After the lapse of time, the signal ST is output.
  • the timer 31 is reset in response to the signal ST from the operation unit 18, measures the normal operation time TD of the converter 6, and outputs a signal TDf indicating the measured time TD. Every time the measured time TD reaches a predetermined time, the measured time TD is reset to 0 seconds.
  • the normal operating time TD of the converter 6 is the time when the AC output power of the commercial AC power supply 21 is supplied to the converter 6 via the electromagnetic contactor 2 and the AC filter F1 and the converter 6 is operated. At this time, the harmonic current generated by the converter 6 flows through the capacitor 4, and the capacitor 4 is gradually deteriorated.
  • the frequency analysis unit 32 captures the waveform of the current IcA obtained by the calculation unit 30 every time the time TD indicated by the output signal TDf of the timer 31 is reset to 0 seconds, and fast Fouriers the waveform of the captured current IcA.
  • the frequency distribution of the current IcA is obtained by performing the conversion.
  • the amplitude detection unit 33 has an amplitude A1 of a current having a frequency of 1 times the switching frequency (6 KHz) and a frequency (12 KHz) twice the switching frequency based on the frequency distribution obtained by the frequency analysis unit 32.
  • the current amplitude A2 and the like are detected.
  • the storage unit 34 stores the amplitudes A1 and A2 detected by the amplitude detection unit 33 as initial amplitude values A1n and A2n, respectively, in response to the signal ST from the operation unit 18.
  • the determination unit 35 compares the initial amplitude values A1n and A2n stored in the storage unit 34 with the amplitudes A1 and A2 detected this time by the amplitude detection unit 33, and based on the comparison result, the life of the capacitor 4 has come to an end. It is determined whether or not it has been done, and a signal ⁇ 35 indicating the determination result is output.
  • the signal ⁇ 35 is set to the "L” level of the deactivation level.
  • the signal ⁇ 35 is set to the “H” level of the activation level.
  • the difference ⁇ A1 A1n-A1 between the initial amplitude value A1n and the amplitude value A1 exceeds the upper limit value A1H
  • the difference ⁇ A2 A2n-A2n between the initial amplitude value A2n and the amplitude value A2 is
  • the upper limit value A2H exceeded, it is determined that the life of the capacitor 4 has expired, and the signal ⁇ 35 is set to the “H” level of the activation level. In other cases, the determination unit 35 sets the signal ⁇ 35 to the “L” level of the deactivation level.
  • the notification unit 36 When the signal ⁇ 35 is set to the activation level “H” level, the notification unit 36 indicates that the life of the capacitor 4 has reached the end of the life of the capacitor 4, by using light, sound, an image, or the like to notify the user of the uninterruptible power supply 1. Notify to.
  • 1,1A non-disruptive power supply T1 AC input terminal, T2 bypass input terminal, T3 battery terminal, T4 AC output terminal, 2,8,14,17 electromagnetic contactor, 3,11,15,40 current detector, 4 , 9, 13 Capacitor, 5, 12 Reactor, 6 Converter, 7 Bidirectional Chopper, 10 Inverter, 16 Semiconductor Switch, 18 Operation Unit, 19, 19A Control Device, 21 Commercial AC Power Supply, 22 Bypass AC Power Supply, 23 Battery, 24 Load, L1, L2 DC line, Q1 to Q6, Q11 to Q16 IGBT, D1 to D6, D11 to D16 diode, 30 calculation unit, 31 timer, 32 frequency analysis unit, 33 amplitude detection unit, 34 storage unit, 35 judgment unit , 36 Notification unit.

Abstract

In an uninterruptable power supply device (1), a current (Ic) flowing through a capacitor (13) connected to an AC terminal of an inverter (10) is detected during operation of the inverter, a high frequency component of the current is detected, the high frequency component detected at this time is compared with a high frequency component detected when use of the capacitor was started, and whether the end of the life of the capacitor has been reached is determined on the basis of the comparison result. Accordingly, the end of life of the capacitor connected to the AC terminal of the inverter can be determined during normal operation of the inverter. In addition, there is no need to separately provide components such as a switch or a resistor for charging the capacitor, and therefore cost reductions of the device can be achieved.

Description

寿命判定装置およびそれを備えた電源装置Life judgment device and power supply device equipped with it
　この発明は寿命判定装置および電源装置に関し、特に、電力変換器の交流端子に接続されたコンデンサの寿命を判定する寿命判定装置と、それを備えた電源装置とに関する。 The present invention relates to a life determination device and a power supply device, and more particularly to a life determination device for determining the life of a capacitor connected to an AC terminal of a power converter, and a power supply device including the life determination device.
　たとえば特開２０１６－１６７９４８号公報（特許文献１）には、電力変換器の直流端子に接続されたコンデンサの寿命を判定する寿命判定装置が開示されている。この寿命判定装置は、電力変換器の出力電流を検出する電流検出器と、コンデンサの端子間電圧を検出する電圧検出器と、電力変換器の出力電流によってコンデンサを所定電圧値に初期充電する初期充電部と、初期充電期間中に電流検出器によって検出された電流を積分して電流積分値を求める電流積分部と、電流積分値、所定電圧値、および初期充電前に電圧検出器によって検出されたコンデンサの端子間電圧に基づいてコンデンサの推定容量値を算出する容量推定部と、予め測定された未使用時のコンデンサの初期容量値と容量推定部によって算出された推定容量値とに基づいて、コンデンサの寿命が到来したか否かを判定する寿命判定部とを備える。 For example, Japanese Patent Application Laid-Open No. 2016-167948 (Patent Document 1) discloses a life determination device for determining the life of a capacitor connected to a DC terminal of a power converter. This life determination device includes a current detector that detects the output current of the power converter, a voltage detector that detects the voltage between the terminals of the capacitor, and an initial charge that initially charges the capacitor to a predetermined voltage value by the output current of the power converter. The charging unit, the current integrating unit that integrates the current detected by the current detector during the initial charging period to obtain the current integrated value, and the current integrated value, the predetermined voltage value, and the voltage detector detected before the initial charging. Based on the capacitance estimation unit that calculates the estimated capacitance value of the capacitor based on the voltage between the terminals of the capacitor, and the initial capacitance value of the unused capacitor measured in advance and the estimated capacitance value calculated by the capacitance estimation unit. , It is provided with a life determination unit for determining whether or not the life of the capacitor has reached the end.
特開２０１６－１６７９４８号公報Japanese Unexamined Patent Publication No. 2016-167948
　しかし、特許文献１には、電力変換器の交流端子に接続されたコンデンサの寿命を判定する寿命判定装置については何ら記載されていない。 However, Patent Document 1 does not describe any life determination device for determining the life of the capacitor connected to the AC terminal of the power converter.
　また、特許文献１の寿命判定装置では、初期充電前の電圧から所定電圧値までコンデンサを充電して推定容量値を算出するので、電力変換器を通常運転しながらコンデンサの寿命を判定することはできない。 Further, in the life determination device of Patent Document 1, since the capacitor is charged from the voltage before the initial charge to a predetermined voltage value and the estimated capacitance value is calculated, it is not possible to determine the life of the capacitor while operating the power converter normally. Can not.
　また、特許文献１の寿命判定装置では、初期充電部として抵抗器およびスイッチを設ける必要があり、装置がコスト高になるという問題がある。 Further, in the life determination device of Patent Document 1, it is necessary to provide a resistor and a switch as the initial charging unit, and there is a problem that the cost of the device becomes high.
　それゆえに、この発明の主たる目的は、電力変換器の交流端子に接続されたコンデンサの寿命を電力変換器の通常運転時に判定することが可能で低コストの寿命判定装置と、それを備えた電源装置とを提供することである。 Therefore, a main object of the present invention is a low-cost life determination device capable of determining the life of a capacitor connected to an AC terminal of a power converter during normal operation of the power converter, and a power supply equipped with the same. It is to provide a device.
　この発明に係る寿命判定装置は、電力変換器の交流端子に接続されたコンデンサの寿命を判定する寿命判定装置であって、電流検出部、高調波検出部、および判定部を備えたものである。電流検出部は、電力変換器の運転時にコンデンサに流れる電流を検出する。高調波検出部は、電流検出部によって検出される電流のうちの高調波成分を検出する。判定部は、コンデンサの使用開始時に高調波検出部によって検出された高調波成分と、高調波検出部によって今回検出された高調波成分とを比較し、その比較結果に基づいてコンデンサの寿命が到来したか否かを判定する。 The life determination device according to the present invention is a life determination device for determining the life of a capacitor connected to an AC terminal of a power converter, and includes a current detection unit, a harmonic detection unit, and a determination unit. .. The current detector detects the current flowing through the capacitor when the power converter is operating. The harmonic detection unit detects the harmonic component of the current detected by the current detection unit. The judgment unit compares the harmonic component detected by the harmonic detection unit at the start of use of the capacitor with the harmonic component detected this time by the harmonic detection unit, and the life of the capacitor is reached based on the comparison result. Determine if it has been done.
　この発明に係る寿命判定装置では、電力変換器の交流端子に接続されたコンデンサに流れる電流を電力変換器の運転時に検出し、その電流のうちの高調波成分を検出し、コンデンサの使用開始時に検出した高調波成分と、今回検出した高調波成分とを比較し、その比較結果に基づいてコンデンサの寿命が到来したか否かを判定する。したがって、電力変換器の交流端子に接続されたコンデンサの寿命を電力変換器の通常運転時に判定することができる。また、コンデンサを充電するための抵抗器、スイッチなどを別途設ける必要がないので、装置の低コスト化を図ることができる。 In the life determination device according to the present invention, the current flowing through the capacitor connected to the AC terminal of the power converter is detected during the operation of the power converter, the harmonic component of the current is detected, and the capacitor is used at the start of use. The detected harmonic component is compared with the harmonic component detected this time, and it is determined whether or not the life of the capacitor has reached the end of the life of the capacitor based on the comparison result. Therefore, the life of the capacitor connected to the AC terminal of the power converter can be determined during the normal operation of the power converter. Further, since it is not necessary to separately provide a resistor, a switch, etc. for charging the capacitor, the cost of the device can be reduced.
実施の形態１による無停電電源装置の構成を示す回路ブロック図である。It is a circuit block diagram which shows the structure of the uninterruptible power supply according to Embodiment 1. FIG. 図１に示すコンバータおよびインバータの構成を示す回路図である。It is a circuit diagram which shows the structure of the converter and the inverter shown in FIG. 図１に示す制御装置のうちのコンデンサ１３の寿命の判定に関連する部分の構成を示すブロック図である。It is a block diagram which shows the structure of the part which is related to the determination of the life of a capacitor 13 in the control apparatus shown in FIG. 図３に示す演算部の動作を説明するためのタイムチャートである。It is a time chart for demonstrating the operation of the arithmetic unit shown in FIG. 図３に示す周波数分析部によって求められるコンデンサ電流の周波数分布を示す図である。It is a figure which shows the frequency distribution of the capacitor current obtained by the frequency analysis unit shown in FIG. 実施の形態１の変更例を示すブロック図である。It is a block diagram which shows the modification example of Embodiment 1. FIG. 実施の形態２による無停電電源装置の構成を示す回路ブロック図である。It is a circuit block diagram which shows the structure of the uninterruptible power supply according to Embodiment 2. 図７に示す制御装置のうちのコンデンサ４の寿命の判定に関連する部分の構成を示すブロック図である。It is a block diagram which shows the structure of the part related to the determination of the life of a capacitor 4 in the control device shown in FIG. 7.
　［実施の形態１］
　図１は、実施の形態１による無停電電源装置１の構成を示す回路ブロック図である。この無停電電源装置１は、商用交流電源２１から供給される三相交流電力を直流電力に一旦変換し、その直流電力を三相交流電力に変換して負荷２４に供給するものである。図１では、図面および説明の簡単化のため、三相（Ｕ相、Ｖ相、Ｗ相）のうちの一相（たとえばＵ相）に対応する部分の回路のみが示されている。 [Embodiment 1]
FIG. 1 is a circuit block diagram showing a configuration of an uninterruptible power supply device 1 according to the first embodiment. The uninterruptible power supply 1 temporarily converts the three-phase AC power supplied from the commercial AC power supply 21 into DC power, converts the DC power into three-phase AC power, and supplies the DC power to the load 24. In FIG. 1, for simplification of drawings and description, only the circuit corresponding to one phase (for example, U phase) of the three phases (U phase, V phase, W phase) is shown.
　図１において、この無停電電源装置１は、交流入力端子Ｔ１、バイパス入力端子Ｔ２、バッテリ端子Ｔ３、および交流出力端子Ｔ４を備える。交流入力端子Ｔ１は、商用交流電源２１から商用周波数の交流電力を受ける。バイパス入力端子Ｔ２は、バイパス交流電源２２から商用周波数の交流電力を受ける。バイパス交流電源２２は、商用交流電源であってもよいし、発電機であっても構わない。 In FIG. 1, the uninterruptible power supply 1 includes an AC input terminal T1, a bypass input terminal T2, a battery terminal T3, and an AC output terminal T4. The AC input terminal T1 receives AC power of a commercial frequency from the commercial AC power supply 21. The bypass input terminal T2 receives commercial frequency AC power from the bypass AC power supply 22. The bypass AC power supply 22 may be a commercial AC power supply or a generator.
　バッテリ端子Ｔ３は、バッテリ（電力貯蔵装置）２３に接続される。バッテリ２３は、直流電力を蓄える。バッテリ２３の代わりにコンデンサが接続されていても構わない。交流出力端子Ｔ４は、負荷２４に接続される。負荷２４は、交流電力によって駆動される。 The battery terminal T3 is connected to the battery (power storage device) 23. The battery 23 stores DC power. A capacitor may be connected instead of the battery 23. The AC output terminal T4 is connected to the load 24. The load 24 is driven by AC power.
　この無停電電源装置１は、さらに、電磁接触器２，８，１４，１７、電流検出器３，１１，１５、コンデンサ４，９，１３、リアクトル５，１２、コンバータ６、双方向チョッパ７、インバータ１０、半導体スイッチ１６、操作部１８、および制御装置１９を備える。 The uninterruptible power supply 1 further includes an electromagnetic contactor 2,8,14,17, a current detector 3,11,15, a capacitor 4,9,13, a reactor 5,12, a converter 6, a bidirectional chopper 7, and the like. It includes an inverter 10, a semiconductor switch 16, an operation unit 18, and a control device 19.
　電磁接触器２の一方端子は交流入力端子Ｔ１に接続され、電磁接触器２の他方端子（ノードＮ１）はリアクトル５の一方端子に接続され、リアクトル５の他方端子はコンバータ６の交流端子６ａに接続される。コンデンサ４は、ノードＮ１と中性点ＮＰとの間に接続される。中性点ＮＰは、たとえば接地電圧を受ける。電磁接触器２は、無停電電源装置１の使用時にオンされ、たとえば無停電電源装置１のメンテナンス時にオフされる。 One terminal of the magnetic contactor 2 is connected to the AC input terminal T1, the other terminal of the magnetic contactor 2 (node N1) is connected to one terminal of the reactor 5, and the other terminal of the reactor 5 is connected to the AC terminal 6a of the converter 6. Be connected. The capacitor 4 is connected between the node N1 and the neutral point NP. The neutral point NP receives, for example, a ground voltage. The magnetic contactor 2 is turned on when the uninterruptible power supply 1 is used, and is turned off, for example, when the uninterruptible power supply 1 is maintained.
　ノードＮ１に現れる交流入力電圧Ｖｉの瞬時値は、制御装置１９によって検出される。交流入力電圧Ｖｉの瞬時値に基づいて、停電の発生の有無などが判別される。電流検出器３は、ノードＮ１に流れる交流入力電流Ｉｉを検出し、その検出値を示す信号Ｉｉｆを制御装置１９に与える。 The instantaneous value of the AC input voltage Vi appearing at the node N1 is detected by the control device 19. Whether or not a power failure has occurred is determined based on the instantaneous value of the AC input voltage Vi. The current detector 3 detects the AC input current Ii flowing through the node N1 and gives a signal If indicating the detected value to the control device 19.
　コンデンサ４およびリアクトル５は、交流フィルタＦ１を構成し、商用周波数の交流電力を通過させるとともに、コンバータ６で発生するスイッチング周波数の電流が商用交流電源２１に通過することを防止する。 The capacitor 4 and the reactor 5 constitute an AC filter F1 to pass AC power of a commercial frequency and prevent a current of a switching frequency generated by the converter 6 from passing to a commercial AC power supply 21.
　コンバータ６は、制御装置１９によって制御され、商用交流電源２１から交流電力が正常に供給されている場合（商用交流電源２１の健全時）には、交流電力を直流電力に変換して直流ラインＬ１に出力する。商用交流電源２１から交流電力が正常に供給されなくなった場合（商用交流電源２１の停電時）には、コンバータ６の運転は停止される。コンバータ６の出力電圧は、所望の値に制御可能になっている。コンデンサ４、リアクトル５、およびコンバータ６は順変換器を構成する。 The converter 6 is controlled by the control device 19, and when the AC power is normally supplied from the commercial AC power supply 21 (when the commercial AC power supply 21 is sound), the AC power is converted into DC power and the DC line L1 is used. Output to. When the AC power is not normally supplied from the commercial AC power supply 21 (during a power failure of the commercial AC power supply 21), the operation of the converter 6 is stopped. The output voltage of the converter 6 can be controlled to a desired value. The capacitor 4, the reactor 5, and the converter 6 constitute a forward converter.
　コンデンサ９は、直流ラインＬ１に接続され、直流ラインＬ１の電圧を平滑化させる。直流ラインＬ１に現れる直流電圧ＶＤＣの瞬時値は、制御装置１９によって検出される。直流ラインＬ１は双方向チョッパ７の高電圧側ノードに接続され、双方向チョッパ７の低電圧側ノードは電磁接触器８を介してバッテリ端子Ｔ３に接続される。 The capacitor 9 is connected to the DC line L1 and smoothes the voltage of the DC line L1. The instantaneous value of the DC voltage VDC appearing on the DC line L1 is detected by the control device 19. The DC line L1 is connected to the high voltage side node of the bidirectional chopper 7, and the low voltage side node of the bidirectional chopper 7 is connected to the battery terminal T3 via the electromagnetic contactor 8.
　電磁接触器８は、無停電電源装置１の使用時はオンされ、たとえば無停電電源装置１およびバッテリ２３のメンテナンス時にオフされる。バッテリ端子Ｔ３に現れるバッテリ２３の端子間電圧ＶＢの瞬時値は、制御装置１９によって検出される。 The magnetic contactor 8 is turned on when the uninterruptible power supply 1 is used, and is turned off when the uninterruptible power supply 1 and the battery 23 are maintained, for example. The instantaneous value of the voltage VB between the terminals of the battery 23 appearing at the battery terminal T3 is detected by the control device 19.
　双方向チョッパ７は、制御装置１９によって制御され、商用交流電源２１の健全時には、コンバータ６によって生成された直流電力をバッテリ２３に蓄え、商用交流電源２１の停電時には、バッテリ２３の直流電力を直流ラインＬ１を介してインバータ１０に供給する。 The bidirectional chopper 7 is controlled by the control device 19, and when the commercial AC power supply 21 is sound, the DC power generated by the converter 6 is stored in the battery 23, and when the commercial AC power supply 21 fails, the DC power of the battery 23 is DC. It is supplied to the inverter 10 via the line L1.
　双方向チョッパ７は、直流電力をバッテリ２３に蓄える場合には、直流ラインＬ１の直流電圧ＶＤＣを降圧してバッテリ２３に与える。また、双方向チョッパ７は、バッテリ２３の直流電力をインバータ１０に供給する場合には、バッテリ２３の端子間電圧ＶＢを昇圧して直流ラインＬ１に出力する。直流ラインＬ１は、インバータ１０の入力ノードに接続されている。 When the bidirectional chopper 7 stores DC power in the battery 23, the bidirectional chopper 7 steps down the DC voltage VDC of the DC line L1 and supplies it to the battery 23. Further, when the bidirectional chopper 7 supplies the DC power of the battery 23 to the inverter 10, the bidirectional chopper 7 boosts the voltage VB between the terminals of the battery 23 and outputs the DC power to the DC line L1. The DC line L1 is connected to the input node of the inverter 10.
　インバータ１０は、制御装置１９によって制御され、コンバータ６または双方向チョッパ７から直流ラインＬ１を介して供給される直流電力を商用周波数の交流電力に変換して出力する。すなわち、インバータ１０は、商用交流電源２１の健全時には、コンバータ６から直流ラインＬ１を介して供給される直流電力を交流電力に変換し、商用交流電源２１の停電時には、バッテリ２３から双方向チョッパ７を介して供給される直流電力を交流電力に変換する。インバータ１０の出力電圧は、所望の値に制御可能になっている。 The inverter 10 is controlled by the control device 19 and converts the DC power supplied from the converter 6 or the bidirectional chopper 7 via the DC line L1 into commercial frequency AC power and outputs it. That is, the inverter 10 converts the DC power supplied from the converter 6 via the DC line L1 into AC power when the commercial AC power supply 21 is sound, and the bidirectional chopper 7 from the battery 23 when the commercial AC power supply 21 fails. Converts the DC power supplied via the AC power into AC power. The output voltage of the inverter 10 can be controlled to a desired value.
　インバータ１０の交流端子１０ａはリアクトル１２の一方端子に接続され、リアクトル１２の他方端子（ノードＮ２）は電磁接触器１４の一方端子に接続され、電磁接触器１４の他方端子（ノードＮ３）は交流出力端子Ｔ４に接続される。コンデンサ１３は、ノードＮ２と中性点ＮＰとの間に接続される。中性点ＮＰは、たとえば接地電圧を受ける。 The AC terminal 10a of the inverter 10 is connected to one terminal of the reactor 12, the other terminal (node N2) of the reactor 12 is connected to one terminal of the magnetic contactor 14, and the other terminal (node N3) of the magnetic contactor 14 is AC. It is connected to the output terminal T4. The capacitor 13 is connected between the node N2 and the neutral point NP. The neutral point NP receives, for example, a ground voltage.
　電流検出器１１は、インバータ１０の出力電流Ｉｏの瞬時値を検出し、その検出値を示す信号Ｉｏｆを制御装置１９に与える。ノードＮ２に現れる交流出力電圧Ｖｏの瞬時値は、制御装置１９によって検出される。 The current detector 11 detects an instantaneous value of the output current Io of the inverter 10 and gives a signal Iof indicating the detected value to the control device 19. The instantaneous value of the AC output voltage Vo appearing at the node N2 is detected by the control device 19.
　リアクトル１２およびコンデンサ１３は、交流フィルタＦ２を構成し、インバータ１０で生成される商用周波数の交流電力を交流出力端子Ｔ４に通過させ、インバータ１０で発生するスイッチング周波数の電流が交流出力端子Ｔ４に通過することを防止する。インバータ１０、リアクトル１２、およびコンデンサ１３は逆変換器を構成する。 The reactor 12 and the capacitor 13 constitute an AC filter F2, and the AC power of the commercial frequency generated by the inverter 10 is passed through the AC output terminal T4, and the current of the switching frequency generated by the inverter 10 is passed through the AC output terminal T4. Prevent it from happening. The inverter 10, the reactor 12, and the capacitor 13 constitute an inverse converter.
　電磁接触器１４は、制御装置１９によって制御され、インバータ１０によって生成された交流電力を負荷２４に供給するインバータ給電モード時にはオンされ、バイパス交流電源２２からの交流電力を負荷２４に供給するバイパス給電モード時にはオフされる。電流検出器１５は、ノードＮ３と交流出力端子Ｔ４との間に流れる負荷電流ＩＬの瞬時値を検出し、その検出値を示す信号ＩＬｆを制御装置１９に与える。 The electromagnetic contactor 14 is controlled by the control device 19 and is turned on in the inverter power supply mode in which the AC power generated by the inverter 10 is supplied to the load 24. The bypass power supply supplies the AC power from the bypass AC power supply 22 to the load 24. It is turned off in mode. The current detector 15 detects an instantaneous value of the load current IL flowing between the node N3 and the AC output terminal T4, and gives a signal ILf indicating the detected value to the control device 19.
　半導体スイッチ１６は、互いに逆並列に接続された一対のサイリスタを含み、バイパス入力端子Ｔ２とノードＮ３との間に接続される。電磁接触器１７は、半導体スイッチ１６に並列接続される。半導体スイッチ１６は、制御装置１９によって制御され、通常はオフされ、インバータ１０が故障した場合には瞬時にオンし、バイパス交流電源２２からの交流電力を負荷２４に供給する。半導体スイッチ１６は、オンしてから所定時間経過後にオフする。 The semiconductor switch 16 includes a pair of thyristors connected in antiparallel to each other, and is connected between the bypass input terminal T2 and the node N3. The magnetic contactor 17 is connected in parallel to the semiconductor switch 16. The semiconductor switch 16 is controlled by the control device 19, is normally turned off, and is turned on instantly when the inverter 10 fails, and supplies AC power from the bypass AC power supply 22 to the load 24. The semiconductor switch 16 is turned off after a predetermined time has elapsed since it was turned on.
　電磁接触器１７は、インバータ１０によって生成された交流電力を負荷２４に供給するインバータ給電モード時にはオフされ、バイパス交流電源２２からの交流電力を負荷２４に供給するバイパス給電モード時にはオンされる。 The electromagnetic contactor 17 is turned off in the inverter power supply mode in which the AC power generated by the inverter 10 is supplied to the load 24, and is turned on in the bypass power supply mode in which the AC power from the bypass AC power supply 22 is supplied to the load 24.
　また、電磁接触器１７は、インバータ１０が故障した場合にオンし、バイパス交流電源２２からの交流電力を負荷２４に供給する。つまり、インバータ１０が故障した場合には、半導体スイッチ１６が瞬時に所定時間だけオンするとともに電磁接触器１７がオンする。これは、半導体スイッチ１６が過熱されて破損するのを防止するためである。 Further, the electromagnetic contactor 17 is turned on when the inverter 10 fails, and supplies AC power from the bypass AC power supply 22 to the load 24. That is, when the inverter 10 fails, the semiconductor switch 16 is instantly turned on for a predetermined time and the electromagnetic contactor 17 is turned on. This is to prevent the semiconductor switch 16 from being overheated and damaged.
　操作部１８は、無停電電源装置１の使用者によって操作される複数のボタン、種々の情報を表示する画像表示部などを含む。使用者が操作部１８を操作することにより、無停電電源装置１の電源をオンおよびオフしたり、バイパス給電モードおよびインバータ給電モードのうちのいずれか一方のモードを選択したり、新品のコンデンサ１３をセットした旨を入力することが可能となっている。 The operation unit 18 includes a plurality of buttons operated by the user of the uninterruptible power supply 1, an image display unit that displays various information, and the like. By operating the operation unit 18, the user can turn on and off the power of the uninterruptible power supply 1, select either the bypass power supply mode or the inverter power supply mode, or use a new capacitor 13. It is possible to enter the fact that is set.
　操作部１８は、新品のコンデンサ１３をセットした旨が入力され、かつインバータ給電モードが選択された場合には、コンデンサ１３の寿命判定の開始を指令する信号ＳＴを制御装置１９に出力する。 When the operation unit 18 is input to the effect that a new capacitor 13 is set and the inverter power supply mode is selected, the operation unit 18 outputs a signal ST instructing the start of the life determination of the capacitor 13 to the control device 19.
　制御装置１９は、操作部１８からの信号、交流入力電圧Ｖｉ、交流入力電流Ｉｉ、直流電圧ＶＤＣ、バッテリ電圧ＶＢ、交流出力電流Ｉｏ、交流出力電圧Ｖｏ、負荷電流ＩＬなどに基づいて無停電電源装置１全体を制御する。すなわち、制御装置１９は、交流入力電圧Ｖｉの検出値に基づいて停電が発生したか否かを検出し、交流入力電圧Ｖｉの位相に同期してコンバータ６およびインバータ１０を制御する。 The control device 19 is a non-disruptive power supply based on a signal from the operation unit 18, AC input voltage Vi, AC input current Ii, DC voltage VDC, battery voltage VB, AC output current Io, AC output voltage Vo, load current IL, and the like. Controls the entire device 1. That is, the control device 19 detects whether or not a power failure has occurred based on the detected value of the AC input voltage Vi, and controls the converter 6 and the inverter 10 in synchronization with the phase of the AC input voltage Vi.
　また制御装置１９は、交流入力電圧Ｖｉ、交流入力電流Ｉｉ、および直流電圧ＶＤＣに基づいてコンバータ６を制御する。制御装置１９は、商用交流電源２１の健全時には、直流電圧ＶＤＣが所望の目標電圧ＶＤＣＴになるようにコンバータ６を制御し、商用交流電源２１の停電時には、コンバータ６の運転を停止させる。 Further, the control device 19 controls the converter 6 based on the AC input voltage Vi, the AC input current Ii, and the DC voltage VDC. The control device 19 controls the converter 6 so that the DC voltage VDC becomes a desired target voltage VDCT when the commercial AC power supply 21 is sound, and stops the operation of the converter 6 when the commercial AC power supply 21 fails.
　また制御装置１９は、直流電圧ＶＤＣおよびバッテリ電圧ＶＢに基づいて双方向チョッパ７を制御する。制御装置１９は、商用交流電源２１の健全時には、バッテリ電圧ＶＢが所望の目標バッテリ電圧ＶＢＴになるように双方向チョッパ７を制御し、商用交流電源２１の停電時には、直流電圧ＶＤＣが所望の目標電圧ＶＤＣＴになるように双方向チョッパ７を制御する。 Further, the control device 19 controls the bidirectional chopper 7 based on the DC voltage VDC and the battery voltage VB. The control device 19 controls the bidirectional chopper 7 so that the battery voltage VB becomes the desired target battery voltage VBT when the commercial AC power supply 21 is sound, and the DC voltage VDC is the desired target when the commercial AC power supply 21 fails. The bidirectional chopper 7 is controlled so that the voltage is VDCT.
　また制御装置１９は、交流出力電流Ｉｏおよび交流出力電圧Ｖｏに基づいて、交流出力電圧Ｖｏが所望の目標電圧ＶｏＴになるようにインバータ１０を制御する。また制御装置１９は、負荷電流ＩＬを常時監視し、たとえば負荷電流ＩＬが過大になった場合には電磁接触器１４，１７および半導体スイッチ１６をオフさせて無停電電源装置１を保護する。 Further, the control device 19 controls the inverter 10 so that the AC output voltage Vo becomes a desired target voltage VoT based on the AC output current Io and the AC output voltage Vo. Further, the control device 19 constantly monitors the load current IL, and when the load current IL becomes excessive, for example, the electromagnetic contactors 14 and 17 and the semiconductor switch 16 are turned off to protect the uninterruptible power supply device 1.
　さらに制御装置１９は、操作部１８からの信号ＳＴに応答して、所定時間が経過する毎にコンデンサ１３の寿命が到来したか否かを判定する。制御装置１９は、寿命判定時には、電流検出器１１の出力信号Ｉｏｆによって示されるインバータ１０の出力電流Ｉｏから、電流検出器１５の出力信号ＩＬｆによって示される負荷電流ＩＬを減算してコンデンサ１３に流れる電流Ｉｃ＝Ｉｏ－ＩＬを求め、その電流Ｉｃの高調波成分を検出する。この高調波成分は、インバータ１０で発生するスイッチング周波数（たとえば６ＫＨｚ）の自然数倍の周波数の電流を含む。 Further, the control device 19 responds to the signal ST from the operation unit 18 and determines whether or not the life of the capacitor 13 has reached every time a predetermined time elapses. At the time of life determination, the control device 19 subtracts the load current IL indicated by the output signal ILf of the current detector 15 from the output current Io of the inverter 10 indicated by the output signal Iof of the current detector 11 and flows to the capacitor 13. The current Ic = Io-IL is obtained, and the harmonic component of the current Ic is detected. This harmonic component includes a current having a frequency that is several times the natural number of the switching frequency (for example, 6 KHz) generated by the inverter 10.
　そして、制御装置１９は、コンデンサ１３の使用開始時に検出した高調波成分と今回検出した高調波成分とを比較し、比較結果に基づいて、コンデンサ１３の寿命が到来したかどうかを判定し、コンデンサ１３の寿命が到来したと判定した場合には、その旨を音、光、画像などを用いて無停電電源装置１の使用者に報知する。コンデンサ１３の寿命判定方法については、後で詳細に説明する。 Then, the control device 19 compares the harmonic component detected at the start of use of the capacitor 13 with the harmonic component detected this time, determines whether or not the life of the capacitor 13 has expired based on the comparison result, and determines whether the capacitor 13 has reached the end of its life. When it is determined that the life of 13 has reached the end of its life, the user of the uninterruptible power supply device 1 is notified to that effect by using sound, light, an image, or the like. The method of determining the life of the capacitor 13 will be described in detail later.
　次に、この無停電電源装置１の使用方法および動作について説明する。初期状態では、商用交流電源２１が健全であり、インバータ給電モードが選択され、半導体スイッチ１６および電磁接触器１７がオフされ、電磁接触器２，８，１４がオンされているものとする。 Next, the usage and operation of this uninterruptible power supply 1 will be described. In the initial state, it is assumed that the commercial AC power supply 21 is sound, the inverter power supply mode is selected, the semiconductor switch 16 and the magnetic contactor 17 are turned off, and the magnetic contactors 2, 8 and 14 are turned on.
　商用交流電源２１から供給される交流電力は、コンバータ６によって直流電力に変換される。この直流電力は、双方向チョッパ７によってバッテリ２３に蓄えられるとともに、インバータ１０によって交流電力に変換される。この交流電力は、交流フィルタＦ２を介して負荷２４に供給される。負荷２４は、交流電力によって運転される。 The AC power supplied from the commercial AC power supply 21 is converted into DC power by the converter 6. This DC power is stored in the battery 23 by the bidirectional chopper 7 and converted into AC power by the inverter 10. This AC power is supplied to the load 24 via the AC filter F2. The load 24 is operated by AC power.
　インバータ１０から交流フィルタＦ２を介して負荷２４に交流電力が供給されると、熱などに起因してコンデンサ１３が徐々に劣化する。コンデンサ１３のインピーダンスは、容量成分と抵抗成分とを含む。コンデンサ１３が劣化するに従って、コンデンサ１３のインピーダンスの抵抗成分が増大し、コンデンサ１３に流れる電流のうちの高調波成分が減少する。 When AC power is supplied from the inverter 10 to the load 24 via the AC filter F2, the capacitor 13 gradually deteriorates due to heat or the like. The impedance of the capacitor 13 includes a capacitance component and a resistance component. As the capacitor 13 deteriorates, the resistance component of the impedance of the capacitor 13 increases, and the harmonic component of the current flowing through the capacitor 13 decreases.
　制御装置１９により、所定時間毎に、電流検出器１１，１５の出力信号Ｉｏｆ，ＩＬｆに基づいてコンデンサ１３に流れる電流Ｉｃの高調波成分が検出され、コンデンサ１３の使用開始時に検出した高調波成分と今回検出した高調波成分とが比較され、その比較結果に基づいて、コンデンサ１３の寿命が到来したかどうかが判定される。コンデンサ１３の寿命が到来したと判定した場合には、その旨が無停電電源装置１の使用者に報知される。 The control device 19 detects the harmonic component of the current Ic flowing through the capacitor 13 based on the output signals If and ILf of the current detectors 11 and 15 at predetermined time intervals, and the harmonic component detected at the start of use of the capacitor 13. Is compared with the harmonic component detected this time, and based on the comparison result, it is determined whether or not the life of the capacitor 13 has reached the end. When it is determined that the life of the capacitor 13 has reached the end of its life, the user of the uninterruptible power supply 1 is notified to that effect.
　コンデンサ１３の寿命が到来した旨が報知された場合、無停電電源装置１の使用者は、操作部１８を操作してバイパス給電モードを選択することにより、電磁接触器１７をオンさせるとともに電磁接触器２，８，１４をオフさせ、コンバータ６、双方向チョッパ７、およびインバータ１０の運転を停止させる。負荷２４は、バイパス交流電源２２から電磁接触器１７を介して供給される交流電力によって駆動される。無停電電源装置１の使用者は、コンデンサ１３を新品と交換する。 When it is notified that the life of the capacitor 13 has expired, the user of the uninterruptible power supply 1 operates the operation unit 18 to select the bypass power supply mode to turn on the magnetic contactor 17 and make electromagnetic contact. The vessels 2, 8 and 14 are turned off, and the operation of the converter 6, the bidirectional chopper 7, and the inverter 10 is stopped. The load 24 is driven by AC power supplied from the bypass AC power supply 22 via the electromagnetic contactor 17. The user of the uninterruptible power supply 1 replaces the capacitor 13 with a new one.
　次に使用者は、操作部１８を操作して新品のコンデンサ１３をセットした旨を入力するとともに、インバータ給電モードを選択する。これにより、コンバータ６、双方向チョッパ７、およびインバータ１０が運転され、電磁接触器２，８，１４がオンされ、電磁接触器１７をオフされ、インバータ１０から交流フィルタＦ２および電磁接触器１４を介して負荷２４に交流電力が供給される。また、所定時間毎にコンデンサ１３の寿命が判定される。 Next, the user operates the operation unit 18 to input that a new capacitor 13 has been set, and selects the inverter power supply mode. As a result, the converter 6, the bidirectional chopper 7, and the inverter 10 are operated, the magnetic contactors 2, 8 and 14 are turned on, the magnetic contactor 17 is turned off, and the AC filter F2 and the electromagnetic contactor 14 are removed from the inverter 10. AC power is supplied to the load 24 via the load 24. Further, the life of the capacitor 13 is determined every predetermined time.
　商用交流電源２１の停電が発生すると、コンバータ６の運転が停止され、バッテリ２３の直流電力が双方向チョッパ７によってインバータ１０に供給される。インバータ１０は、双方向チョッパ７からの直流電力を交流電力に変換して負荷２４に供給する。したがって、バッテリ２３に直流電力が蓄えられている期間は、負荷２４の運転を継続することができる。 When a power failure occurs in the commercial AC power supply 21, the operation of the converter 6 is stopped, and the DC power of the battery 23 is supplied to the inverter 10 by the bidirectional chopper 7. The inverter 10 converts the DC power from the bidirectional chopper 7 into AC power and supplies it to the load 24. Therefore, the operation of the load 24 can be continued while the DC power is stored in the battery 23.
　また、インバータ給電モード時においてインバータ１０が故障した場合には、半導体スイッチ１６が瞬時にオンし、電磁接触器１４がオフするとともに、電磁接触器１７がオンする。これにより、バイパス交流電源２２からの交流電力が半導体スイッチ１６および電磁接触器１７を介して負荷２４に供給され、負荷２４の運転が継続される。一定時間後に半導体スイッチ１６がオフされ、半導体スイッチ１６が過熱されて破損することが防止される。 Further, when the inverter 10 fails in the inverter power supply mode, the semiconductor switch 16 is instantly turned on, the magnetic contactor 14 is turned off, and the magnetic contactor 17 is turned on. As a result, the AC power from the bypass AC power supply 22 is supplied to the load 24 via the semiconductor switch 16 and the electromagnetic contactor 17, and the operation of the load 24 is continued. After a certain period of time, the semiconductor switch 16 is turned off to prevent the semiconductor switch 16 from being overheated and damaged.
　次に、コンデンサ１３の寿命判定方法について詳細に説明する。図２は、図１に示したコンバータ６およびインバータ１０の構成を示す回路図である。図１では三相交流電圧のうちの一相に関連する部分のみを示したが、図２では三相に関連する部分を示している。 Next, the method of determining the life of the capacitor 13 will be described in detail. FIG. 2 is a circuit diagram showing the configurations of the converter 6 and the inverter 10 shown in FIG. In FIG. 1, only the portion related to one phase of the three-phase AC voltage is shown, but in FIG. 2, the portion related to the three phases is shown.
　図２において、コンバータ６は、ＩＧＢＴ（Insulated　Gate　Bipolar　Transistor）Ｑ１～Ｑ６およびダイオードＤ１～Ｄ６を含む。ＩＧＢＴは、スイッチング素子を構成する。ＩＧＢＴＱ１～Ｑ３のコレクタはともに直流ラインＬ１に接続され、それらのエミッタはそれぞれ交流端子６ａ，６ｂ，６ｃに接続される。ＩＧＢＴＱ４～Ｑ６のコレクタはそれぞれ交流端子６ａ，６ｂ，６ｃに接続され、それらのエミッタはともに直流ラインＬ２に接続される。ダイオードＤ１～Ｄ６は、それぞれＩＧＢＴＱ１～Ｑ６に逆並列に接続される。 In FIG. 2, the converter 6 includes IGBTs (Insulated Gate Bipolar Transistors) Q1 to Q6 and diodes D1 to D6. The IGBT constitutes a switching element. The collectors of IGBT Q1 to Q3 are both connected to the DC line L1, and their emitters are connected to the AC terminals 6a, 6b, 6c, respectively. The collectors of IGBT Q4 to Q6 are connected to the AC terminals 6a, 6b, 6c, respectively, and their emitters are both connected to the DC line L2. Diodes D1 to D6 are connected to IGBT Q1 to Q6 in antiparallel, respectively.
　交流端子６ａ，６ｂ，６ｃは、商用交流電源２１から３組の電磁接触器２および交流フィルタＦ１（図１）を介して供給される三相交流電圧を受ける。交流端子６ａ～６ｃに供給される三相交流電圧は、ダイオードＤ１～Ｄ６によって三相全波整流されて直流電圧ＶＤＣに変換され、コンデンサ９の端子間に与えられる。 The AC terminals 6a, 6b, 6c receive a three-phase AC voltage supplied from the commercial AC power supply 21 via three sets of electromagnetic contactors 2 and an AC filter F1 (FIG. 1). The three-phase AC voltage supplied to the AC terminals 6a to 6c is three-phase full-wave rectified by the diodes D1 to D6, converted into a DC voltage VDC, and applied between the terminals of the capacitor 9.
　ＩＧＢＴＱ１，Ｑ４はそれぞれゲート信号Ａｕ，Ｂｕによって制御され、ＩＧＢＴＱ２，Ｑ５はそれぞれゲート信号Ａｖ，Ｂｖによって制御され、ＩＧＢＴＱ３，Ｑ６はそれぞれゲート信号Ａｗ，Ｂｗによって制御される。ゲート信号Ｂｕ，Ｂｖ，Ｂｗは、それぞれゲート信号Ａｕ，Ａｖ，Ａｗの反転信号である。 The IGBT Q1 and Q4 are controlled by the gate signals Au and Bu, respectively, the IGBT Q2 and Q5 are controlled by the gate signals Av and Bv, respectively, and the IGBT Q3 and Q6 are controlled by the gate signals Aw and Bw, respectively. The gate signals Bu, Bv, and Bw are inverted signals of the gate signals Au, Av, and Aw, respectively.
　ＩＧＢＴＱ１～Ｑ３は、それぞれゲート信号Ａｕ，Ａｖ，Ａｗが「Ｈ」レベルにされた場合にオンし、それぞれゲート信号Ａｕ，Ａｖ，Ａｗが「Ｌ」レベルにされた場合にオフする。ＩＧＢＴＱ４～Ｑ６は、それぞれゲート信号Ｂｕ，Ｂｖ，Ｂｗが「Ｈ」レベルにされた場合にオンし、それぞれゲート信号Ｂｕ，Ｂｖ，Ｂｗが「Ｌ」レベルにされた場合にオフする。 IGBTQ1 to Q3 are turned on when the gate signals Au, Av, and Aw are set to the "H" level, and turned off when the gate signals Au, Av, and Aw are set to the "L" level, respectively. IGBTQ4 to Q6 are turned on when the gate signals Bu, Bv, and Bw are set to the "H" level, and turned off when the gate signals Bu, Bv, and Bw are set to the "L" level, respectively.
　ゲート信号Ａｕ，Ｂｕ，Ａｖ，Ｂｖ，Ａｗ，Ｂｗの各々は、パルス信号列であり、スイッチング周波数（たとえば６ＫＨｚ）のＰＷＭ（Pulse　Width　Modulation）信号である。ゲート信号Ａｕ，Ｂｕの位相とゲート信号Ａｖ，Ｂｖの位相とゲート信号Ａｗ，Ｂｗの位相とは１２０度ずつずれている。ゲート信号Ａｕ，Ｂｕ，Ａｖ，Ｂｖ，Ａｗ，Ｂｗは、制御装置１９によって生成される。ＩＧＢＴＱ１～Ｑ６の各々は、スイッチング周波数でオンおよびオフされる。 Each of the gate signals Au, Bu, Av, Bv, Aw, and Bw is a pulse signal sequence and is a PWM (Pulse Width Modulation) signal having a switching frequency (for example, 6 KHz). The phases of the gate signals Au and Bu, the phases of the gate signals Av and Bv, and the phases of the gate signals Aw and Bw are deviated by 120 degrees. The gate signals Au, Bu, Av, Bv, Aw, Bw are generated by the control device 19. Each of IGBT Q1 to Q6 is turned on and off at the switching frequency.
　ゲート信号Ａｕ，Ｂｕ，Ａｖ，Ｂｖ，Ａｗ，ＢｗによってＩＧＢＴＱ１～Ｑ６の各々を所定のタイミングでオンおよびオフさせるとともに、ＩＧＢＴＱ１～Ｑ６の各々のオン時間を調整することにより、コンデンサ９の端子間電圧ＶＤＣを商用周波数の三相交流電圧に変換して交流端子６ａ～６ｃに出力することが可能となっている。 The voltage between the terminals of the capacitor 9 is adjusted by turning each of the IGBT Q1 to Q6 on and off at a predetermined timing by the gate signals Au, Bu, Av, Bv, Aw, and Bw, and adjusting the on time of each of the IGBT Q1 to Q6. It is possible to convert the VDC into a commercial frequency three-phase AC voltage and output it to the AC terminals 6a to 6c.
　コンバータ６から出力される三相交流電圧の位相を商用交流電源２１から供給される三相交流電圧の位相よりも遅らせると、商用交流電源２１からコンバータ６を介してコンデンサ９に電力が供給され、コンデンサ９の端子間電圧ＶＤＣが上昇する。 When the phase of the three-phase AC voltage output from the converter 6 is delayed from the phase of the three-phase AC voltage supplied from the commercial AC power supply 21, power is supplied from the commercial AC power supply 21 to the capacitor 9 via the converter 6. The voltage VDC between the terminals of the capacitor 9 rises.
　逆に、コンバータ６から出力される三相交流電圧の位相を商用交流電源２１から供給される三相交流電圧の位相よりも進ませると、コンデンサ９からコンバータ６を介して商用交流電源２１に電力が供給され、コンデンサ９の端子間電圧ＶＤＣが下降する。したがって、コンバータ６から出力される三相交流電圧の位相を調整することにより、コンデンサ９の端子間電圧ＶＤＣを所望の目標電圧ＶＤＣＴに維持することができる。 On the contrary, when the phase of the three-phase AC voltage output from the converter 6 is advanced from the phase of the three-phase AC voltage supplied from the commercial AC power supply 21, power is supplied from the capacitor 9 to the commercial AC power supply 21 via the converter 6. Is supplied, and the voltage VDC between the terminals of the capacitor 9 drops. Therefore, by adjusting the phase of the three-phase AC voltage output from the converter 6, the voltage VDC between the terminals of the capacitor 9 can be maintained at a desired target voltage VDCT.
　コンバータ６から出力される三相交流電圧は、商用周波数の基本波成分と、高調波成分とを含む。高調波成分は、スイッチング周波数の自然数倍の高周波成分を含む。交流フィルタＦ１は、商用周波数の基本波成分を通過させ、高調波成分を遮断する。 The three-phase AC voltage output from the converter 6 includes a fundamental wave component of a commercial frequency and a harmonic component. The harmonic component includes a high frequency component that is several times the natural number of the switching frequency. The AC filter F1 passes the fundamental wave component of the commercial frequency and cuts off the harmonic component.
　また、インバータ１０は、コンバータ６と同様の構成であり、ＩＧＢＴＱ１１～Ｑ１６およびダイオードＤ１１～Ｄ１６を含む。ＩＧＢＴは、スイッチング素子を構成する。ＩＧＢＴＱ１１～Ｑ１３のコレクタはともに直流ラインＬ１に接続され、それらのエミッタはそれぞれ交流端子１０ａ，１０ｂ，１０ｃに接続される。ＩＧＢＴＱ１４～Ｑ１６のコレクタはそれぞれ交流端子１０ａ，１０ｂ，１０ｃに接続され、それらのエミッタはともに直流ラインＬ２に接続される。ダイオードＤ１１～Ｄ１６は、それぞれＩＧＢＴＱ１１～Ｑ１６に逆並列に接続される。 Further, the inverter 10 has the same configuration as the converter 6, and includes the IGBT Q11 to Q16 and the diodes D11 to D16. The IGBT constitutes a switching element. The collectors of IGBT Q11 to Q13 are both connected to the DC line L1, and their emitters are connected to the AC terminals 10a, 10b, and 10c, respectively. The collectors of IGBT Q14 to Q16 are connected to the AC terminals 10a, 10b, and 10c, respectively, and their emitters are both connected to the DC line L2. The diodes D11 to D16 are connected to the IGBT Q11 to Q16 in antiparallel, respectively.
　ＩＧＢＴＱ１１，Ｑ１４はそれぞれゲート信号Ｘｕ，Ｙｕによって制御され、ＩＧＢＴＱ１２，Ｑ１５はそれぞれゲート信号Ｘｖ，Ｙｖによって制御され、ＩＧＢＴＱ１３，Ｑ１６はそれぞれゲート信号Ｘｗ，Ｙｗによって制御される。ゲート信号Ｙｕ，Ｙｖ，Ｙｗは、それぞれゲート信号Ｘｕ，Ｘｖ，Ｘｗの反転信号である。 The IGBT Q11 and Q14 are controlled by the gate signals Xu and Yu, respectively, the IGBT Q12 and Q15 are controlled by the gate signals Xv and Yv, respectively, and the IGBT Q13 and Q16 are controlled by the gate signals Xw and Yw, respectively. The gate signals Yu, Yv, and Yw are inverted signals of the gate signals Xu, Xv, and Xw, respectively.
　ＩＧＢＴＱ１１～Ｑ１３は、それぞれゲート信号Ｘｕ，Ｘｖ，Ｘｗが「Ｈ」レベルにされた場合にオンし、それぞれゲート信号Ｘｕ，Ｘｖ，Ｘｗが「Ｌ」レベルにされた場合にオフする。ＩＧＢＴＱ１４～Ｑ１６は、それぞれゲート信号Ｙｕ，Ｙｖ，Ｙｗが「Ｈ」レベルにされた場合にオンし、それぞれゲート信号Ｙｕ，Ｙｖ，Ｙｗが「Ｌ」レベルにされた場合にオフする。 IGBTQ11 to Q13 are turned on when the gate signals Xu, Xv, Xw are set to the "H" level, and turned off when the gate signals Xu, Xv, Xw are set to the "L" level, respectively. IGBTQ14 to Q16 are turned on when the gate signals Yu, Yv, and Yw are set to the "H" level, and turned off when the gate signals Yu, Yv, and Yw are set to the "L" level, respectively.
　ゲート信号Ｘｕ，Ｙｕ，Ｘｖ，Ｙｖ，Ｘｗ，Ｙｗの各々は、パルス信号列であり、スイッチング周波数（たとえば６ＫＨｚ）のＰＷＭ信号である。ゲート信号Ｘｕ，Ｙｕの位相とゲート信号Ｘｖ，Ｙｖの位相とゲート信号Ｘｗ，Ｙｗの位相とは１２０度ずつずれている。ゲート信号Ｘｕ，Ｙｕ，Ｘｖ，Ｙｖ，Ｘｗ，Ｙｗは、制御装置１９によって生成される。ＩＧＢＴＱ１１～Ｑ１６の各々は、スイッチング周波数でオンおよびオフされる。 Each of the gate signals Xu, Yu, Xv, Yv, Xw, and Yw is a pulse signal sequence and is a PWM signal having a switching frequency (for example, 6 KHz). The phases of the gate signals Xu and Yu, the phases of the gate signals Xv and Yv, and the phases of the gate signals Xw and Yw are deviated by 120 degrees. The gate signals Xu, Yu, Xv, Yv, Xw, Yw are generated by the control device 19. Each of IGBT Q11 to Q16 is turned on and off at the switching frequency.
　ゲート信号Ｘｕ，Ｙｕ，Ｘｖ，Ｙｖ，Ｘｗ，ＹｗによってＩＧＢＴＱ１１～Ｑ１６の各々を所定のタイミングでオンおよびオフさせるとともに、ＩＧＢＴＱ１１～Ｑ１６の各々のオン時間を調整することにより、コンデンサ９の端子間電圧ＶＤＣを商用周波数の三相交流電圧に変換して交流端子１０ａ，１０ｂ，１０ｃに出力することが可能となっている。インバータ１０によって生成された三相交流電圧は、三組の交流フィルタＦ２および電磁接触器１４を介して負荷２４に供給される。 The voltage between the terminals of the capacitor 9 is adjusted by turning each of the IGBT Q11 to Q16 on and off at a predetermined timing by the gate signals Xu, Yu, Xv, Yv, Xw, and Yw and adjusting the on time of each of the IGBT Q11 to Q16. It is possible to convert the VDC into a commercial frequency three-phase AC voltage and output it to the AC terminals 10a, 10b, and 10c. The three-phase AC voltage generated by the inverter 10 is supplied to the load 24 via the three sets of AC filters F2 and the electromagnetic contactor 14.
　インバータ１０から出力される三相交流電圧は、商用周波数の基本波成分と、高調波成分とを含む。高調波成分は、スイッチング周波数の自然数倍の高周波成分を含む。交流フィルタＦ２は、商用周波数の基本波成分を通過させ、高調波成分を遮断する。 The three-phase AC voltage output from the inverter 10 includes a fundamental wave component of a commercial frequency and a harmonic component. The harmonic component includes a high frequency component that is several times the natural number of the switching frequency. The AC filter F2 passes the fundamental wave component of the commercial frequency and cuts off the harmonic component.
　しかし、コンデンサ１３の使用時間に応じてコンデンサ１３が徐々に劣化する。コンデンサ１３が劣化すると、コンデンサ１３の抵抗成分が増大し、コンデンサ１３に高調波成分が流れ難くなり、交流フィルタＦ２を通過する高調波成分が増大する。この高調波成分は負荷２４に悪影響を及ぼすので、コンデンサ１３の寿命が到来した場合にはコンデンサ１３を新品と交換する必要がある。 However, the capacitor 13 gradually deteriorates according to the usage time of the capacitor 13. When the capacitor 13 deteriorates, the resistance component of the capacitor 13 increases, it becomes difficult for the harmonic component to flow through the capacitor 13, and the harmonic component passing through the AC filter F2 increases. Since this harmonic component adversely affects the load 24, it is necessary to replace the capacitor 13 with a new one when the life of the capacitor 13 is reached.
　そこで、本実施の形態１では、インバータ１０の通常運転時に電流検出器１１，１５の検出結果に基づいてコンデンサ１３に流れる電流Ｉｃを求め、その電流Ｉｃの高調波成分を検出する。そして、コンデンサ１３の使用開始時に検出した高調波成分と今回検出した高調波成分とを比較し、その比較結果に基づいてコンデンサ１３の寿命が到来したか否かを判定し、コンデンサ１３の寿命が到来したと判定した場合には、その旨を無停電電源装置１の使用者に報知する。 Therefore, in the first embodiment, the current Ic flowing through the capacitor 13 is obtained based on the detection results of the current detectors 11 and 15 during the normal operation of the inverter 10, and the harmonic component of the current Ic is detected. Then, the harmonic component detected at the start of use of the capacitor 13 is compared with the harmonic component detected this time, and based on the comparison result, it is determined whether or not the life of the capacitor 13 has reached, and the life of the capacitor 13 is reached. If it is determined that it has arrived, the user of the uninterruptible power supply device 1 is notified to that effect.
　図３は、制御装置１９のうちのコンデンサ１３の寿命の判定に関連する部分を示すブロック図である。図３において、制御装置１９は、演算部３０、タイマー３１、周波数分析部３２、振幅検出部３３、記憶部３４、判定部３５、および報知部３６を含む。電流検出器１１，１５、操作部１８、および制御装置１９は、コンデンサ１３の寿命を判定する寿命判定装置を構成する。 FIG. 3 is a block diagram showing a part of the control device 19 related to the determination of the life of the capacitor 13. In FIG. 3, the control device 19 includes a calculation unit 30, a timer 31, a frequency analysis unit 32, an amplitude detection unit 33, a storage unit 34, a determination unit 35, and a notification unit 36. The current detectors 11 and 15, the operation unit 18, and the control device 19 constitute a life determination device for determining the life of the capacitor 13.
　演算部３０は、電流検出器１１（図１）の出力信号Ｉｏｆによって示されるインバータ１０の出力電流Ｉｏの瞬時値から、電流検出器１５（図１）の出力信号ＩＬｆによって示される負荷電流ＩＬの瞬時値を減算して、コンデンサ１３に流れる電流Ｉｃの瞬時値を求める。 The calculation unit 30 uses the instantaneous value of the output current Io of the inverter 10 indicated by the output signal Iof of the current detector 11 (FIG. 1) to the load current IL indicated by the output signal ILf of the current detector 15 (FIG. 1). The instantaneous value is subtracted to obtain the instantaneous value of the current Ic flowing through the capacitor 13.
　図４は、演算部３０の動作を説明するためのタイムチャートである。図４において、（Ａ）は、インバータ１０から出力されて３つの交流フィルタＦ２を通過した三相交流電圧Ｖｕ，Ｖｖ，Ｖｗの波形を示し、（Ｂ）はインバータ１０から出力されて３つの電流検出器１１によって検出される三相交流電流Ｉｕ，Ｉｖ，Ｉｗの波形を示している。 FIG. 4 is a time chart for explaining the operation of the calculation unit 30. In FIG. 4, (A) shows the waveforms of the three-phase AC voltages Vu, Vv, and Vw output from the inverter 10 and passed through the three AC filters F2, and (B) is the three currents output from the inverter 10. The waveforms of the three-phase alternating currents Iu, Iv, and Iw detected by the detector 11 are shown.
　図１および図３では、図面および説明の簡単化のため、Ｕ相、Ｖ相、およびＷ相のうちのＵ相に対応する部分のみが示されている。ノードＮ２の交流電圧Ｖｏ（図１）は、Ｕ相の交流電圧Ｖｕに対応している。電流検出器１１の出力信号Ｉｏｆ（図１）によって示されるインバータ１０の交流出力電流Ｉｏは、Ｕ相の交流電流Ｉｕに対応している。 In FIGS. 1 and 3, only the portion corresponding to the U phase of the U phase, the V phase, and the W phase is shown for the sake of simplification of drawings and explanations. The AC voltage Vo (FIG. 1) of the node N2 corresponds to the U-phase AC voltage Vu. The AC output current Io of the inverter 10 indicated by the output signal If (FIG. 1) of the current detector 11 corresponds to the U-phase AC current Iu.
　（Ｃ）は、ノードＮ２（図１）とコンデンサ１３との間に電流検出器を別途設け、その電流検出器によって実際に検出したコンデンサ電流ＩｃＤの波形を示し、（Ｄ）は電流検出器１５の出力信号ＩＬｆ（図１）によって示される負荷電流ＩＬの波形を示し、（Ｅ）は演算部３０（図３）によって算出されたコンデンサ１３に流れる電流Ｉｃの波形を示している。 (C) shows the waveform of the capacitor current IcD actually detected by a current detector separately provided between the node N2 (FIG. 1) and the capacitor 13, and (D) shows the current detector 15. The waveform of the load current IL shown by the output signal ILf (FIG. 1) of the above is shown, and FIG. 3 (E) shows the waveform of the current Ic flowing through the capacitor 13 calculated by the calculation unit 30 (FIG. 3).
　また、図４において、時刻ｔ１～ｔ３の期間では、コンデンサ１３の劣化前（使用開始時）におけるコンデンサ電流Ｉｃなどの波形が示され、時刻ｔ３～ｔ５の期間では、コンデンサ１３の劣化後におけるコンデンサ電流Ｉｃなどの波形が示されている。 Further, in FIG. 4, in the period from time t1 to t3, the waveform of the capacitor current Ic or the like before the deterioration of the capacitor 13 (at the start of use) is shown, and in the period from time t3 to t5, the capacitor after the deterioration of the capacitor 13 is shown. Waveforms such as current Ic are shown.
　図４（Ａ）に示すように、インバータ１０および交流フィルタＦ２によって生成された三相交流電圧Ｖｕ（すなわちＶｏ），Ｖｖ，Ｖｗの各々は商用周波数で正弦波状に変化する。三相交流電圧Ｖｕ（すなわちＶｏ），Ｖｖ，Ｖｗの位相は、１２０度ずつずれている。 As shown in FIG. 4A, each of the three-phase AC voltages Vu (that is, Vo), Vv, and Vw generated by the inverter 10 and the AC filter F2 changes in a sine wave shape at a commercial frequency. The phases of the three-phase AC voltages Vu (that is, Vo), Vv, and Vw are shifted by 120 degrees.
　また図４（Ｂ）に示すように、インバータ１０から出力される三相交流電流Ｉｕ（すなわちＩｏ），Ｉｖ，Ｉｗの各々は、基本的には商用周波数で正弦波状に変化する。三相交流電流Ｉｕ（すなわちＩｏ），Ｉｖ，Ｉｗの位相は、１２０度ずつずれている。三相交流電流Ｉｕ（すなわちＩｏ），Ｉｖ，Ｉｗの各々は、商用周波数の基本波成分と、スイッチング周波数の自然数倍の周波数を有する高調波成分とを含む。高調波成分は、基本波成分に重畳している。 Further, as shown in FIG. 4B, each of the three-phase alternating currents Iu (that is, Io), Iv, and Iw output from the inverter 10 basically changes in a sinusoidal shape at a commercial frequency. The phases of the three-phase alternating currents Iu (that is, Io), Iv, and Iw are shifted by 120 degrees. Each of the three-phase alternating currents Iu (ie, Io), Iv, and Iw contains a fundamental wave component of a commercial frequency and a harmonic component having a frequency that is a natural number multiple of the switching frequency. The harmonic component is superimposed on the fundamental wave component.
　また図４（Ｃ）に示すように、別途設けられた電流検出器によって実際に検出されたコンデンサ電流ＩｃＤは、基本的には商用周波数で正弦波状に変化する。コンデンサ電流ＩｃＤの位相は、交流電圧Ｖｕ（すなわちＶｏ）の位相よりも９０度進んでいる。コンデンサ電流ＩｃＤは、商用周波数の基本波成分と、スイッチング周波数の自然数倍の周波数を有する高調波成分とを含む。高調波成分は、基本波成分に重畳している。 Further, as shown in FIG. 4C, the capacitor current IcD actually detected by the separately provided current detector basically changes in a sinusoidal shape at a commercial frequency. The phase of the capacitor current IcD is 90 degrees ahead of the phase of the AC voltage Vu (ie, Vo). The capacitor current IcD includes a fundamental wave component of a commercial frequency and a harmonic component having a frequency that is a natural number multiple of the switching frequency. The harmonic component is superimposed on the fundamental wave component.
　図４（Ｃ）から分かるように、コンデンサ１３の劣化後の電流ＩｃＤの高調波成分の振幅は、コンデンサ１３の劣化前の電流ＩｃＤの高調波成分の振幅よりも小さいことが分かる。これは、コンデンサ１３が劣化するとコンデンサ１３の抵抗成分が増大し、コンデンサ１３に高調波電流が流れ難くなることに対応している。 As can be seen from FIG. 4C, it can be seen that the amplitude of the harmonic component of the current IcD after the deterioration of the capacitor 13 is smaller than the amplitude of the harmonic component of the current IcD before the deterioration of the capacitor 13. This corresponds to the fact that when the capacitor 13 deteriorates, the resistance component of the capacitor 13 increases, and it becomes difficult for the harmonic current to flow through the capacitor 13.
　また図４（Ｄ）に示すように、負荷電流ＩＬは、基本的には商用周波数で正弦波状に変化する。負荷電流ＩＬの位相は、交流電圧Ｖｕ（すなわちＶｏ）の位相と同じである。コンデンサ１３の劣化前では、負荷電流ＩＬに高調波成分は含まれていない。コンデンサ１３の劣化後では、負荷電流ＩＬに若干の高調波成分が含まれている。 Further, as shown in FIG. 4 (D), the load current IL basically changes in a sinusoidal shape at a commercial frequency. The phase of the load current IL is the same as the phase of the AC voltage Vu (that is, Vo). Before the deterioration of the capacitor 13, the load current IL does not contain a harmonic component. After the deterioration of the capacitor 13, the load current IL contains some harmonic components.
　また図４（Ｅ）に示すように、演算部３０（図３）によって算出されたコンデンサ電流Ｉｃの波形は、電流検出器によって実際に検出されたコンデンサ電流ＩｃＤの波形（図４（Ｃ））と一致している。したがって、本実施の形態１では、コンデンサ１３に流れる電流Ｉｃを検出するための電流検出器を別途設ける必要はないので、装置構成の簡単化と装置の低コスト化を図ることができる。 Further, as shown in FIG. 4 (E), the waveform of the capacitor current Ic calculated by the calculation unit 30 (FIG. 3) is the waveform of the capacitor current IcD actually detected by the current detector (FIG. 4 (C)). Is consistent with. Therefore, in the first embodiment, it is not necessary to separately provide a current detector for detecting the current Ic flowing through the capacitor 13, so that the device configuration can be simplified and the cost of the device can be reduced.
　再び図３を参照して、操作部１８（図１）は、無停電電源装置１の使用者により、新品のコンデンサ１３をセットしたことが入力され、インバータ給電モードの実行が指示された場合に、装置動作の安定化に必要な所定時間の経過後に信号ＳＴを出力する。 With reference to FIG. 3 again, when the user of the uninterruptible power supply 1 inputs that a new capacitor 13 has been set and is instructed to execute the inverter power supply mode, the operation unit 18 (FIG. 1) is instructed to execute the inverter power supply mode. , The signal ST is output after a predetermined time required for stabilizing the operation of the device has elapsed.
　タイマー３１は、操作部１８からの信号ＳＴに応答してリセットされ、インバータ１０の通常運転時間ＴＤを計測し、計測した時間ＴＤを示す信号ＴＤｆを出力する。計測した時間ＴＤが所定時間に到達する毎に、計測時間ＴＤは０秒にリセットされる。 The timer 31 is reset in response to the signal ST from the operation unit 18, measures the normal operation time TD of the inverter 10, and outputs a signal TDf indicating the measured time TD. Every time the measured time TD reaches a predetermined time, the measured time TD is reset to 0 seconds.
　ここで、インバータ１０の通常運転時間ＴＤとは、インバータ１０の交流出力電力が交流フィルタＦ２および電磁接触器１４を介して負荷２４に供給されている時間である。このとき、高調波成分がコンデンサ１３に流れてコンデンサ１３が徐々に劣化する。 Here, the normal operation time TD of the inverter 10 is the time during which the AC output power of the inverter 10 is supplied to the load 24 via the AC filter F2 and the electromagnetic contactor 14. At this time, the harmonic component flows through the capacitor 13, and the capacitor 13 gradually deteriorates.
　周波数分析部３２は、タイマー３１の出力信号ＴＤｆによって示される時間ＴＤが０秒にリセットされる毎に、演算部３０によって求められた電流Ｉｃの波形を取り込み、取り込んだ電流Ｉｃの波形に高速フーリエ変換を施して電流Ｉｃの周波数分布を求める。 The frequency analysis unit 32 captures the waveform of the current Ic obtained by the calculation unit 30 every time the time TD indicated by the output signal TDf of the timer 31 is reset to 0 seconds, and fast Fouriers the waveform of the captured current Ic. The frequency distribution of the current Ic is obtained by performing the conversion.
　図５は、コンデンサ１３に流れる電流Ｉｃの周波数分布を示す図である。図５において、（Ａ）はコンデンサ１３の劣化前（すなわち使用開始時）における電流Ｉｃの周波数分布を示し、（Ｂ）はコンデンサ１３の劣化後における電流Ｉｃの周波数分布を示している。 FIG. 5 is a diagram showing the frequency distribution of the current Ic flowing through the capacitor 13. In FIG. 5, (A) shows the frequency distribution of the current Ic before the deterioration of the capacitor 13 (that is, at the start of use), and (B) shows the frequency distribution of the current Ic after the deterioration of the capacitor 13.
　図５において、コンデンサ１３に流れる電流Ｉｃは、商用周波数（５０Ｈｚ）の基本波成分と、高調波成分とを含む。高調波成分は、主に、スイッチング周波数（６ＫＨｚ）のＮ倍（たとえば１倍）の周波数の高周波成分（第１の電流）と、スイッチング周波数のＭ倍（たとえば２倍）の周波数の高周波成分（第２の電流）とを含む。Ｎは自然数であり、ＭはＮと異なる自然数である。 In FIG. 5, the current Ic flowing through the capacitor 13 includes a fundamental wave component of a commercial frequency (50 Hz) and a harmonic component. The harmonic components are mainly a high frequency component (first current) having a frequency N times (for example, 1 times) the switching frequency (6 KHz) and a high frequency component having a frequency M times (for example, 2 times) the switching frequency (for example, 2 times). Second current) and included. N is a natural number and M is a natural number different from N.
　図５から分かるように、コンデンサ１３の劣化後における高調波成分の振幅は、コンデンサ１３の劣化前における高調波成分の振幅よりも小さくなっている。これは、コンデンサ１３の劣化が進行することによってコンデンサ１３の抵抗成分が増大し、コンデンサ１３に流れる高調波成分が減少したことに対応している。 As can be seen from FIG. 5, the amplitude of the harmonic component after the deterioration of the capacitor 13 is smaller than the amplitude of the harmonic component before the deterioration of the capacitor 13. This corresponds to the fact that the resistance component of the capacitor 13 increases and the harmonic component flowing through the capacitor 13 decreases as the deterioration of the capacitor 13 progresses.
　再び図３を参照して、振幅検出部３３は、周波数分析部３２によって求められた周波数分布に基づいて、スイッチング周波数（６ＫＨｚ）の１倍の周波数を有する電流の振幅Ａ１と、スイッチング周波数の２倍の周波数（１２ＫＨｚ）を有する電流の振幅Ａ２とを検出する。 With reference to FIG. 3 again, the amplitude detection unit 33 has an amplitude A1 of a current having a frequency of 1 times the switching frequency (6KHz) and a switching frequency of 2 based on the frequency distribution obtained by the frequency analysis unit 32. The amplitude A2 of the current having a double frequency (12 KHz) is detected.
　記憶部３４は、操作部１８からの信号ＳＴに応答して、振幅検出部３３によって検出された振幅Ａ１，Ａ２をそれぞれ初期振幅値Ａ１ｎ，Ａ２ｎとして記憶する。判定部３５は、記憶部３４に記憶された初期振幅値Ａ１ｎ，Ａ２ｎと、振幅検出部３３によって今回検出された振幅Ａ１，Ａ２とを比較し、比較結果に基づいて、コンデンサ１３の寿命が到来したか否かを判定し、判定結果を示す信号φ３５を出力する。 The storage unit 34 stores the amplitudes A1 and A2 detected by the amplitude detection unit 33 as initial amplitude values A1n and A2n, respectively, in response to the signal ST from the operation unit 18. The determination unit 35 compares the initial amplitude values A1n and A2n stored in the storage unit 34 with the amplitudes A1 and A2 detected this time by the amplitude detection unit 33, and based on the comparison result, the life of the capacitor 13 has come to an end. It is determined whether or not it has been done, and a signal φ35 indicating the determination result is output.
　コンデンサ１３の寿命が未だ到来していないと判定された場合には、信号φ３５は非活性化レベルの「Ｌ」レベルにされる。コンデンサ１３の寿命が到来した判定された場合には、信号φ３５は活性化レベルの「Ｈ」レベルにされる。 When it is determined that the life of the capacitor 13 has not reached yet, the signal φ35 is set to the “L” level of the deactivation level. When it is determined that the life of the capacitor 13 has come to an end, the signal φ35 is set to the “H” level of the activation level.
　具体的には判定部３５は、初期振幅値Ａ１ｎ（第１の振幅）と振幅Ａ１（第２の振幅）との差ΔＡ１＝Ａ１ｎ－Ａ１が上限値Ａ１Ｈを超え、かつ初期振幅値Ａ２ｎ（第３の振幅）と振幅Ａ２（第４の振幅）との差ΔＡ２＝Ａ２ｎ－Ａ２ｎが上限値Ａ２Ｈを超えた場合に、コンデンサ１３の寿命が到来したと判定し、信号φ３５を活性化レベルの「Ｈ」レベルにする。それ以外の場合には判定部３５は、信号φ３５を非活性化レベルの「Ｌ」レベルにする。 Specifically, in the determination unit 35, the difference ΔA1 = A1n−A1 between the initial amplitude value A1n (first amplitude) and the amplitude A1 (second amplitude) exceeds the upper limit value A1H, and the initial amplitude value A2n (first amplitude). When the difference ΔA2 = A2n−A2n between (amplitude of 3) and amplitude A2 (fourth amplitude) exceeds the upper limit value A2H, it is determined that the life of the capacitor 13 has reached the end, and the signal φ35 is set to the activation level “ Set to H "level. In other cases, the determination unit 35 sets the signal φ35 to the “L” level of the deactivation level.
　報知部３６は、信号φ３５が活性化レベルの「Ｈ」レベルにされた場合には、コンデンサ１３の寿命が到来したことを、光、音、画像などを用いて無停電電源装置１の使用者に報知する。 When the signal φ35 is set to the activation level “H” level, the notification unit 36 indicates that the life of the capacitor 13 has reached the end of the life of the capacitor 13 by using light, sound, an image, or the like to notify the user of the uninterruptible power supply 1. Notify to.
　次に、無停電電源装置１におけるコンデンサ１３の寿命判定動作について説明する。初期状態では、バイパス給電モードが選択されており、新品のコンデンサ１３がセットされたものとする。無停電電源装置１の使用者によって操作部１８が操作され、新品のコンデンサ１３をセットしたことが入力され、インバータ給電モードが選択されると、電磁接触器２，８，１４がオンされ、コンバータ６、双方向チョッパ７、およびインバータ１０の運転が開始され、電磁接触器１７がオフされる。 Next, the life determination operation of the capacitor 13 in the uninterruptible power supply 1 will be described. In the initial state, it is assumed that the bypass feeding mode is selected and a new capacitor 13 is set. When the operation unit 18 is operated by the user of the uninterruptible power supply 1, it is input that a new capacitor 13 is set, and the inverter power supply mode is selected, the electromagnetic contactors 2, 8 and 14 are turned on and the converter is converted. 6. The operation of the bidirectional chopper 7 and the inverter 10 is started, and the electromagnetic contactor 17 is turned off.
　商用交流電源２１から供給される交流電力がコンバータ６によって直流電力に変換され、その直流電力が双方向チョッパ７によってバッテリ２３に蓄えられるとともに、インバータ１０によって交流電力に変換されて負荷２４に供給される。インバータ１０の出力電流Ｉｏは電流検出器１１によって検出され、負荷電流ＩＬは電流検出器１５によって検出される。演算部３０（図３）により、インバータ１０の出力電流Ｉｏから負荷電流ＩＬが減算されてコンデンサ１３に流れる電流Ｉｃが算出される。 The AC power supplied from the commercial AC power supply 21 is converted into DC power by the converter 6, the DC power is stored in the battery 23 by the bidirectional chopper 7, and is converted into AC power by the inverter 10 and supplied to the load 24. To. The output current Io of the inverter 10 is detected by the current detector 11, and the load current IL is detected by the current detector 15. The calculation unit 30 (FIG. 3) subtracts the load current IL from the output current Io of the inverter 10 to calculate the current Ic flowing through the capacitor 13.
　装置動作の安定化に必要な所定時間の経過後に、操作部１８から信号ＳＴが出力される。信号ＳＴに応答してタイマー３１がリセットされ、インバータ１０の運転時間ＴＤが０秒にリセットされた後に運転時間ＴＤの計測が開始される。インバータ１０の運転時間ＴＤが所定時間に到達する度に、インバータ１０の運転時間ＴＤが０秒にリセットされる。 The signal ST is output from the operation unit 18 after a predetermined time required for stabilizing the operation of the device has elapsed. The timer 31 is reset in response to the signal ST, and the operation time TD of the inverter 10 is reset to 0 seconds, and then the measurement of the operation time TD is started. Every time the operation time TD of the inverter 10 reaches a predetermined time, the operation time TD of the inverter 10 is reset to 0 seconds.
　運転時間ＴＤが０秒にリセットされると、演算部３０によって算出されるコンデンサ電流Ｉｃの波形が周波数分析部３２に取り込まれ、コンデンサ電流Ｉｃの周波数分布が求められる。振幅検出部３３により、コンデンサ電流Ｉｃの周波数分布から、スイッチング周波数（６ＫＨｚ）の１倍の周波数を有する電流の振幅Ａ１と、スイッチング周波数の２倍の周波数（１２ＫＨｚ）を有する電流の振幅Ａ２とが検出される。 When the operation time TD is reset to 0 seconds, the waveform of the capacitor current Ic calculated by the calculation unit 30 is taken into the frequency analysis unit 32, and the frequency distribution of the capacitor current Ic is obtained. From the frequency distribution of the capacitor current Ic, the amplitude detection unit 33 determines that the amplitude A1 of the current having a frequency of 1 times the switching frequency (6 KHz) and the amplitude A2 of the current having a frequency twice the switching frequency (12 KHz). Detected.
　記憶部３４は、操作部１８からの信号ＳＴに応答して、振幅検出部３３によって検出された振幅Ａ１，Ａ２をそれぞれ初期振幅値Ａ１ｎ，Ａ２ｎとして記憶する。インバータ１０の運転時間ＴＤが所定時間に到達する度に、周波数分析部３２によってコンデンサ電流Ｉｃの周波数分布が求められ、振幅検出部３３によって振幅Ａ１，Ａ２が検出される。 The storage unit 34 stores the amplitudes A1 and A2 detected by the amplitude detection unit 33 as initial amplitude values A1n and A2n, respectively, in response to the signal ST from the operation unit 18. Every time the operating time TD of the inverter 10 reaches a predetermined time, the frequency analysis unit 32 obtains the frequency distribution of the capacitor current Ic, and the amplitude detection unit 33 detects the amplitudes A1 and A2.
　振幅検出部３３によって今回検出された振幅Ａ１，Ａ２と、記憶部３４に記憶された初期振幅値Ａ１ｎ，Ａ２ｎとが判定部３５によって比較され、比較結果に基づいて、コンデンサ１３の寿命が到来したか否かが判定される。判定部３５によってコンデンサ１３の寿命が到来したと判定された場合には、その旨が報知部３６によって無停電電源装置１の使用者に報知される。 The amplitudes A1 and A2 detected this time by the amplitude detection unit 33 and the initial amplitude values A1n and A2n stored in the storage unit 34 are compared by the determination unit 35, and the life of the capacitor 13 has come to an end based on the comparison result. Whether or not it is determined. When the determination unit 35 determines that the life of the capacitor 13 has reached the end, the notification unit 36 notifies the user of the uninterruptible power supply device 1 to that effect.
　これに応じて使用者は、操作部１８を用いてバイパス給電モードを選択する。これにより、電磁接触器２，８，１４がオフされ、電磁接触器１７がオンされ、バイパス交流電源２２から電磁接触器１７を介して負荷２４に交流電力が供給され、負荷２４の運転が継続される。また、コンバータ６、双方向チョッパ７、およびインバータ１０の運転が停止される。 In response to this, the user selects the bypass power supply mode using the operation unit 18. As a result, the magnetic contactors 2, 8 and 14 are turned off, the magnetic contactor 17 is turned on, AC power is supplied from the bypass AC power supply 22 to the load 24 via the magnetic contactor 17, and the operation of the load 24 is continued. Will be done. Further, the operation of the converter 6, the bidirectional chopper 7, and the inverter 10 is stopped.
　使用者は、寿命が到来したコンデンサ１３を新品のコンデンサ１３と交換した後、操作部１８を操作して、新品のコンデンサ１３がセットされたことと、インバータ給電モードの実行を指示する。これにより、電磁接触器２，８，１４がオンされ、コンバータ６、双方向チョッパ７、およびインバータ１０の運転が開始され、電磁接触器１７がオフされ、負荷２４はインバータ１０からの交流電力によって運転される。また、新品のコンデンサ１３の寿命の判定が開始される。 The user replaces the capacitor 13 that has reached the end of its life with a new capacitor 13, and then operates the operation unit 18 to instruct that the new capacitor 13 is set and that the inverter power supply mode is executed. As a result, the magnetic contactors 2, 8 and 14 are turned on, the converter 6, the bidirectional chopper 7 and the inverter 10 are started to operate, the magnetic contactor 17 is turned off, and the load 24 is powered by the AC power from the inverter 10. Be driven. Further, the determination of the life of the new capacitor 13 is started.
　以上のように、この実施の形態１では、インバータ１０の交流端子１０ａに接続されたコンデンサ１３に流れる電流Ｉｃをインバータ１０の通常運転時に検出し、その電流Ｉｃのうちの高調波成分を検出し、コンデンサの使用開始時に検出した高調波成分と今回検出した高調波成分とを比較し、その比較結果に基づいてコンデンサ１３の寿命が到来したか否かを判定する。したがって、インバータ１０を通常運転しながらコンデンサ１３の寿命を判定することができる。また、特許文献１と比べ、コンデンサ１３を充電するための抵抗器、スイッチなどを別途設ける必要がないので、装置の低コスト化を図ることができる。 As described above, in the first embodiment, the current Ic flowing through the capacitor 13 connected to the AC terminal 10a of the inverter 10 is detected during normal operation of the inverter 10, and the harmonic component of the current Ic is detected. , The harmonic component detected at the start of use of the capacitor is compared with the harmonic component detected this time, and it is determined whether or not the life of the capacitor 13 has reached the end of the life of the capacitor 13 based on the comparison result. Therefore, the life of the capacitor 13 can be determined while the inverter 10 is normally operated. Further, as compared with Patent Document 1, since it is not necessary to separately provide a resistor, a switch, or the like for charging the capacitor 13, the cost of the device can be reduced.
　なお、この実施の形態１では、初期振幅値Ａ１ｎと振幅値Ａ１との差ΔＡ１＝Ａ１ｎ－Ａ１が上限値Ａ１Ｈを超えた第１の条件（ΔＡ１＞Ａ１Ｈ）と、初期振幅値Ａ２ｎと振幅値Ａ２との差ΔＡ２＝Ａ２ｎ－Ａ２ｎが上限値Ａ２Ｈを超えた第２の条件（ΔＡ２＞Ａ２Ｈ）との両方の条件が満たされた場合に、コンデンサ１３の寿命が到来したと判定したが、これに限るものではなく、第１および第２の条件のうちのいずれか１つの条件が満たされた場合にコンデンサ１３の寿命が到来したと判定しても構わない。 In the first embodiment, the first condition (ΔA1> A1H) in which the difference ΔA1 = A1n−A1 between the initial amplitude value A1n and the amplitude value A1 exceeds the upper limit value A1H, and the initial amplitude value A2n and the amplitude value. When both the conditions of the second condition (ΔA2> A2H) in which the difference ΔA2 = A2n−A2n from A2 exceeds the upper limit value A2H are satisfied, it is determined that the life of the capacitor 13 has come to an end. However, it may be determined that the life of the capacitor 13 has reached the end when any one of the first and second conditions is satisfied.
　図６は、実施の形態１の変更例を示すブロック図であって、図３と対比される図である。図６を参照して、この変更例が実施の形態１と異なる点は、判定部３５が判定部３５Ａと置換されている点である。判定部３５Ａは、振幅値Ａ１と初期振幅値Ａ１ｎの比Ａ１／Ａ１ｎが下限値Ａ１Ｌよりも低下し、かつ振幅値Ａ２と初期振幅値Ａ２ｎの比Ａ２／Ａ２ｎが下限値Ａ２Ｌよりも低下した場合に、コンデンサ１３の寿命が到来したと判定して、信号φ３５を活性化レベルの「Ｈ」レベルにする。他の構成および動作は、実施の形態１と同じであるので、その説明は繰り返さない。この変更例でも、実施の形態１と同じ効果が得られる。 FIG. 6 is a block diagram showing a modified example of the first embodiment, and is a diagram to be compared with FIG. With reference to FIG. 6, the difference between this modification and the first embodiment is that the determination unit 35 is replaced with the determination unit 35A. In the determination unit 35A, when the ratio A1 / A1n of the amplitude value A1 and the initial amplitude value A1n is lower than the lower limit value A1L and the ratio A2 / A2n of the amplitude value A2 and the initial amplitude value A2n is lower than the lower limit value A2L. In addition, it is determined that the life of the capacitor 13 has reached the end, and the signal φ35 is set to the “H” level of the activation level. Since other configurations and operations are the same as those in the first embodiment, the description thereof will not be repeated. Even in this modified example, the same effect as that of the first embodiment can be obtained.
　なお、この変更例では、振幅値Ａ１と初期振幅値Ａ１ｎの比Ａ１／Ａ１ｎが下限値Ａ１Ｌよりも低下した第３の条件（Ａ１／Ａ１ｎ＜Ａ１Ｌ）と、振幅値Ａ２と初期振幅値Ａ２ｎの比Ａ２／Ａ２ｎが下限値Ａ２Ｌよりも低下した第４の条件（Ａ２／Ａ２ｎ＜Ａ２Ｌ）との両方の条件が満たされた場合に、コンデンサ１３の寿命が到来したと判定したが、これに限るものではなく、第３および第４の条件のうちのいずれか１つの条件が満たされた場合にコンデンサ１３の寿命が到来したと判定しても構わない。 In this modification, the third condition (A1 / A1n <A1L) in which the ratio A1 / A1n of the amplitude value A1 and the initial amplitude value A1n is lower than the lower limit value A1L, and the amplitude value A2 and the initial amplitude value A2n. When both the conditions of the fourth condition (A2 / A2n <A2L) in which the ratio A2 / A2n is lower than the lower limit value A2L are satisfied, it is determined that the life of the capacitor 13 has come to an end, but this is limited to this. However, it may be determined that the life of the capacitor 13 has reached the end when any one of the third and fourth conditions is satisfied.
　［実施の形態２］
　図２で説明したように、コンデンサ９が充電された後には、コンバータ６は、コンデンサ９の端子間電圧ＶＤＣを交流電圧に変換し、交流フィルタＦ１を介して商用交流電源２１に出力する。商用交流電源２１（すなわち電力系統）には多数の負荷（図示せず）が接続されている。コンデンサ９から見れば、コンバータ６および交流フィルタＦ１と、インバータ１０および交流フィルタＦ２とは、同じ構成である。交流フィルタＦ１に含まれるコンデンサ４も、コンデンサ１３と同様に劣化する。そこで、本実施の形態２では、コンデンサ４の寿命を判定する。 [Embodiment 2]
As described with reference to FIG. 2, after the capacitor 9 is charged, the converter 6 converts the terminal voltage VDC of the capacitor 9 into an AC voltage and outputs the voltage to the commercial AC power supply 21 via the AC filter F1. A large number of loads (not shown) are connected to the commercial AC power supply 21 (that is, the power system). From the viewpoint of the capacitor 9, the converter 6 and the AC filter F1 and the inverter 10 and the AC filter F2 have the same configuration. The capacitor 4 included in the AC filter F1 also deteriorates in the same manner as the capacitor 13. Therefore, in the second embodiment, the life of the capacitor 4 is determined.
　図７は、実施の形態２による無停電電源装置１Ａの構成を示す回路ブロック図であって、図１と対比される図である。図７を参照して、この無停電電源装置１Ａが実施の形態１の無停電電源装置１と異なる点は電流検出器４０が追加され、制御装置１９が制御装置１９Ａで置換されている点である。 FIG. 7 is a circuit block diagram showing the configuration of the uninterruptible power supply device 1A according to the second embodiment, and is a diagram to be compared with FIG. 1. With reference to FIG. 7, the uninterruptible power supply 1A differs from the uninterruptible power supply 1 of the first embodiment in that the current detector 40 is added and the control device 19 is replaced by the control device 19A. be.
　電流検出器４０は、コンバータ６の入力電流（すなわちリアクトル５に流れる電流）Ｉｉｃを検出し、その検出値を示す信号Ｉｉｃｆを出力する。制御装置１９Ａは、インバータ給電モード時に、電流検出器４０の出力信号Ｉｉｃｆによって示されるコンバータ６の入力電流Ｉｉｃから、電流検出器３の出力信号Ｉｉｆによって示される交流入力電流Ｉｉを減算してコンデンサ４に流れる電流ＩｃＡ＝Ｉｉｃ－Ｉｉを求め、その電流ＩｃＡの高調波成分を検出する。 The current detector 40 detects the input current (that is, the current flowing through the reactor 5) Iic of the converter 6 and outputs the signal Iicf indicating the detected value. In the inverter power supply mode, the control device 19A subtracts the AC input current Ii indicated by the output signal If of the current detector 3 from the input current Iic of the converter 6 indicated by the output signal Iicf of the current detector 40 to obtain the capacitor 4. The current IcA = Iic-Ii flowing through the current IcA is obtained, and the harmonic component of the current IcA is detected.
　そして、制御装置１９Ａは、コンデンサ４の使用開始時に検出した高調波成分と今回検出した高調波成分とを比較し、比較結果に基づいて、コンデンサ４の寿命が到来したかどうかを判定し、コンデンサ４の寿命が到来したと判定した場合には、その旨を音、光、画像などを用いて無停電電源装置１Ａの使用者に報知する。 Then, the control device 19A compares the harmonic component detected at the start of use of the capacitor 4 with the harmonic component detected this time, determines whether or not the life of the capacitor 4 has expired based on the comparison result, and determines whether the capacitor 4 has reached the end of its life. When it is determined that the life of 4 has reached the end of its life, the user of the uninterruptible power supply device 1A is notified by using sound, light, an image, or the like.
　図８は、制御装置１９Ａのうちのコンデンサ４の寿命の判定に関連する部分を示すブロック図であって、図３と対比される図である。図８を参照して、制御装置１９Ａは、制御装置１９と同様に、演算部３０、タイマー３１、周波数分析部３２、振幅検出部３３、記憶部３４、判定部３５、および報知部３６を含む。電流検出器３，４０、操作部１８、および制御装置１９Ａは、コンデンサ４の寿命を判定する寿命判定装置を構成する。 FIG. 8 is a block diagram showing a portion of the control device 19A related to the determination of the life of the capacitor 4, and is a diagram to be compared with FIG. With reference to FIG. 8, the control device 19A includes a calculation unit 30, a timer 31, a frequency analysis unit 32, an amplitude detection unit 33, a storage unit 34, a determination unit 35, and a notification unit 36, similarly to the control device 19. .. The current detectors 3 and 40, the operation unit 18, and the control device 19A constitute a life determination device for determining the life of the capacitor 4.
　演算部３０は、電流検出器４０の出力信号Ｉｉｃｆによって示されるコンバータ６の入力電流Ｉｉｃの瞬時値から、電流検出器３の出力信号Ｉｉｆによって示される交流入力電流Ｉｉの瞬時値を減算して、コンデンサ４に流れる電流ＩｃＡの瞬時値を求める。 The calculation unit 30 subtracts the instantaneous value of the AC input current Ii indicated by the output signal If of the current detector 3 from the instantaneous value of the input current Iic of the converter 6 indicated by the output signal Iicf of the current detector 40. The instantaneous value of the current IcA flowing through the capacitor 4 is obtained.
　操作部１８は、無停電電源装置１の使用者により、新品のコンデンサ４をセットしたことが入力され、インバータ給電モードの実行が指示された場合に、装置動作の安定化に必要な所定時間の経過後に信号ＳＴを出力する。 When the user of the uninterruptible power supply 1 inputs that a new capacitor 4 has been set and is instructed to execute the inverter power supply mode, the operation unit 18 has a predetermined time required for stabilizing the operation of the device. After the lapse of time, the signal ST is output.
　タイマー３１は、操作部１８からの信号ＳＴに応答してリセットされ、コンバータ６の通常運転時間ＴＤを計測し、計測した時間ＴＤを示す信号ＴＤｆを出力する。計測した時間ＴＤが所定時間に到達する毎に、計測時間ＴＤは０秒にリセットされる。 The timer 31 is reset in response to the signal ST from the operation unit 18, measures the normal operation time TD of the converter 6, and outputs a signal TDf indicating the measured time TD. Every time the measured time TD reaches a predetermined time, the measured time TD is reset to 0 seconds.
　ここで、コンバータ６の通常運転時間ＴＤとは、商用交流電源２１の交流出力電力が電磁接触器２および交流フィルタＦ１を介してコンバータ６に供給され、コンバータ６が運転されている時間である。このとき、コンバータ６で発生する高調波電流がコンデンサ４に流れてコンデンサ４が徐々に劣化される。 Here, the normal operating time TD of the converter 6 is the time when the AC output power of the commercial AC power supply 21 is supplied to the converter 6 via the electromagnetic contactor 2 and the AC filter F1 and the converter 6 is operated. At this time, the harmonic current generated by the converter 6 flows through the capacitor 4, and the capacitor 4 is gradually deteriorated.
　周波数分析部３２は、タイマー３１の出力信号ＴＤｆによって示される時間ＴＤが０秒にリセットされる毎に、演算部３０によって求められた電流ＩｃＡの波形を取り込み、取り込んだ電流ＩｃＡの波形に高速フーリエ変換を施して電流ＩｃＡの周波数分布を求める。 The frequency analysis unit 32 captures the waveform of the current IcA obtained by the calculation unit 30 every time the time TD indicated by the output signal TDf of the timer 31 is reset to 0 seconds, and fast Fouriers the waveform of the captured current IcA. The frequency distribution of the current IcA is obtained by performing the conversion.
　振幅検出部３３は、周波数分析部３２によって求められた周波数分布に基づいて、スイッチング周波数（６ＫＨｚ）の１倍の周波数を有する電流の振幅Ａ１と、スイッチング周波数の２倍の周波数（１２ＫＨｚ）を有する電流の振幅Ａ２とを検出する。 The amplitude detection unit 33 has an amplitude A1 of a current having a frequency of 1 times the switching frequency (6 KHz) and a frequency (12 KHz) twice the switching frequency based on the frequency distribution obtained by the frequency analysis unit 32. The current amplitude A2 and the like are detected.
　記憶部３４は、操作部１８からの信号ＳＴに応答して、振幅検出部３３によって検出された振幅Ａ１，Ａ２をそれぞれ初期振幅値Ａ１ｎ，Ａ２ｎとして記憶する。判定部３５は、記憶部３４に記憶された初期振幅値Ａ１ｎ，Ａ２ｎと、振幅検出部３３によって今回検出された振幅Ａ１，Ａ２とを比較し、比較結果に基づいて、コンデンサ４の寿命が到来したか否かを判定し、判定結果を示す信号φ３５を出力する。 The storage unit 34 stores the amplitudes A1 and A2 detected by the amplitude detection unit 33 as initial amplitude values A1n and A2n, respectively, in response to the signal ST from the operation unit 18. The determination unit 35 compares the initial amplitude values A1n and A2n stored in the storage unit 34 with the amplitudes A1 and A2 detected this time by the amplitude detection unit 33, and based on the comparison result, the life of the capacitor 4 has come to an end. It is determined whether or not it has been done, and a signal φ35 indicating the determination result is output.
　コンデンサ４の寿命が未だ到来していないと判定された場合には、信号φ３５は非活性化レベルの「Ｌ」レベルにされる。コンデンサ４の寿命が到来した判定された場合には、信号φ３５は活性化レベルの「Ｈ」レベルにされる。 If it is determined that the life of the capacitor 4 has not reached yet, the signal φ35 is set to the "L" level of the deactivation level. When it is determined that the life of the capacitor 4 has come to an end, the signal φ35 is set to the “H” level of the activation level.
　具体的には判定部３５は、初期振幅値Ａ１ｎと振幅値Ａ１との差ΔＡ１＝Ａ１ｎ－Ａ１が上限値Ａ１Ｈを超え、かつ初期振幅値Ａ２ｎと振幅値Ａ２との差ΔＡ２＝Ａ２ｎ－Ａ２ｎが上限値Ａ２Ｈを超えた場合に、コンデンサ４の寿命が到来したと判定し、信号φ３５を活性化レベルの「Ｈ」レベルにする。それ以外の場合には判定部３５は、信号φ３５を非活性化レベルの「Ｌ」レベルにする。 Specifically, in the determination unit 35, the difference ΔA1 = A1n-A1 between the initial amplitude value A1n and the amplitude value A1 exceeds the upper limit value A1H, and the difference ΔA2 = A2n-A2n between the initial amplitude value A2n and the amplitude value A2 is When the upper limit value A2H is exceeded, it is determined that the life of the capacitor 4 has expired, and the signal φ35 is set to the “H” level of the activation level. In other cases, the determination unit 35 sets the signal φ35 to the “L” level of the deactivation level.
　報知部３６は、信号φ３５が活性化レベルの「Ｈ」レベルにされた場合には、コンデンサ４の寿命が到来したことを、光、音、画像などを用いて無停電電源装置１の使用者に報知する。 When the signal φ35 is set to the activation level “H” level, the notification unit 36 indicates that the life of the capacitor 4 has reached the end of the life of the capacitor 4, by using light, sound, an image, or the like to notify the user of the uninterruptible power supply 1. Notify to.
　他の構成および動作は、実施の形態１と同じであるので、その説明は繰り返さない。この実施の形態２でも、実施の形態１と同じ動作が得られる。 Since other configurations and operations are the same as those in the first embodiment, the description thereof will not be repeated. Also in the second embodiment, the same operation as that of the first embodiment can be obtained.
　なお、上記実施の形態１，２および種々の変更例を適宜組み合わせてもよいことは言うまでもない。 Needless to say, the above embodiments 1 and 2 and various modified examples may be appropriately combined.
　今回開示された実施の形態はすべての点で例示であって制限的なものではないと考えられるべきである。本発明は上記した説明ではなくて請求の範囲によって示され、請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。 The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope of the claims.
　１，１Ａ　無停電電源装置、Ｔ１　交流入力端子、Ｔ２　バイパス入力端子、Ｔ３　バッテリ端子、Ｔ４　交流出力端子、２，８，１４，１７　電磁接触器、３，１１，１５，４０　電流検出器、４，９，１３　コンデンサ、５，１２　リアクトル、６　コンバータ、７　双方向チョッパ、１０　インバータ、１６　半導体スイッチ、１８　操作部、１９，１９Ａ　制御装置、２１　商用交流電源、２２　バイパス交流電源、２３　バッテリ、２４　負荷、Ｌ１，Ｌ２　直流ライン、Ｑ１～Ｑ６，Ｑ１１～Ｑ１６　ＩＧＢＴ、Ｄ１～Ｄ６，Ｄ１１～Ｄ１６　ダイオード、３０　演算部、３１　タイマー、３２　周波数分析部、３３　振幅検出部、３４　記憶部、３５　判定部、３６　報知部。 1,1A non-disruptive power supply, T1 AC input terminal, T2 bypass input terminal, T3 battery terminal, T4 AC output terminal, 2,8,14,17 electromagnetic contactor, 3,11,15,40 current detector, 4 , 9, 13 Capacitor, 5, 12 Reactor, 6 Converter, 7 Bidirectional Chopper, 10 Inverter, 16 Semiconductor Switch, 18 Operation Unit, 19, 19A Control Device, 21 Commercial AC Power Supply, 22 Bypass AC Power Supply, 23 Battery, 24 Load, L1, L2 DC line, Q1 to Q6, Q11 to Q16 IGBT, D1 to D6, D11 to D16 diode, 30 calculation unit, 31 timer, 32 frequency analysis unit, 33 amplitude detection unit, 34 storage unit, 35 judgment unit , 36 Notification unit.

Claims (13)

  1. 　電力変換器の交流端子に接続されたコンデンサの寿命を判定する寿命判定装置であって、
    　前記電力変換器の運転時に前記コンデンサに流れる電流を検出する電流検出部と、
    　前記電流検出部によって検出される電流のうちの高調波成分を検出する高調波検出部と、
    　前記コンデンサの使用開始時に前記高調波検出部によって検出された高調波成分と、前記高調波検出部によって今回検出された高調波成分とを比較し、その比較結果に基づいて前記コンデンサの寿命が到来したか否かを判定する判定部とを備える、寿命判定装置。     It is a life judgment device that judges the life of the capacitor connected to the AC terminal of the power converter.
    A current detector that detects the current flowing through the capacitor during operation of the power converter, and
    A harmonic detection unit that detects a harmonic component of the current detected by the current detection unit, and a harmonic detection unit.
    The harmonic component detected by the harmonic detection unit at the start of use of the capacitor is compared with the harmonic component detected this time by the harmonic detection unit, and the life of the capacitor is reached based on the comparison result. A life determination device including a determination unit for determining whether or not a capacitor has been used.
  2. 　前記電力変換器は、スイッチング周波数でオンおよびオフされるスイッチング素子を含み、
    　前記高調波成分は、前記スイッチング周波数のＮ倍の周波数を有する第１の電流を含み、Ｎは自然数であり、
    　前記高調波検出部は、
    　前記電流検出部によって検出される電流の周波数分布を求める周波数分析部と、
    　前記周波数分析部によって求められた周波数分布に基づいて、前記第１の電流の振幅を検出する振幅検出部とを含み、
    　前記判定部は、前記コンデンサの使用開始時に前記振幅検出部によって検出された前記第１の電流の第１の振幅と、前記振幅検出部によって今回検出された前記第１の電流の第２の振幅とを比較し、その比較結果に基づいて前記コンデンサの寿命が到来したか否かを判定する、請求項１に記載の寿命判定装置。     The power converter comprises a switching element that is turned on and off at a switching frequency.
    The harmonic component comprises a first current having a frequency N times the switching frequency, where N is a natural number.
    The harmonic detection unit
    A frequency analysis unit that obtains the frequency distribution of the current detected by the current detection unit, and
    The frequency detection unit includes an amplitude detection unit that detects the amplitude of the first current based on the frequency distribution obtained by the frequency analysis unit.
    The determination unit has a first amplitude of the first current detected by the amplitude detection unit at the start of use of the capacitor and a second amplitude of the first current detected this time by the amplitude detection unit. The life determination device according to claim 1, wherein the capacitor is compared with the above and it is determined whether or not the life of the capacitor has reached the end of the life of the capacitor based on the comparison result.
  3. 　前記周波数分析部は、前記電流検出部によって求められた前記コンデンサに流れる電流の波形に高速フーリエ変換を施して前記周波数分布を求める、請求項２に記載の寿命判定装置。 The life determination device according to claim 2, wherein the frequency analysis unit performs a fast Fourier transform on the waveform of the current flowing through the capacitor obtained by the current detection unit to obtain the frequency distribution.
  4. 　前記判定部は、前記第１および第２の振幅の差に基づいて、前記コンデンサの寿命が到来したか否かを判定する、請求項２に記載の寿命判定装置。 The life determination device according to claim 2, wherein the determination unit determines whether or not the life of the capacitor has reached the end of the life of the capacitor based on the difference between the first and second amplitudes.
  5. 　前記判定部は、前記第２および第１の振幅の比率に基づいて、前記コンデンサの寿命が到来したか否かを判定する、請求項２に記載の寿命判定装置。 The life determination device according to claim 2, wherein the determination unit determines whether or not the life of the capacitor has reached the end of the life of the capacitor based on the ratio of the second and first amplitudes.
  6. 　前記高調波成分は、前記スイッチング周波数のＭ倍の周波数を有する第２の電流を含み、Ｍは、Ｎと異なる自然数であり、
    　前記振幅検出部は、前記周波数分析部によって求められた周波数分布に基づいて、前記第２の電流の振幅をさらに検出し、
    　前記判定部は、前記コンデンサの使用開始時に前記振幅検出部によって検出された前記第２の電流の第３の振幅と前記振幅検出部によって今回検出された前記第２の電流の第４の振幅とを比較し、その比較結果と、前記第１および第２の振幅の比較結果とに基づいて前記コンデンサの寿命が到来したか否かを判定する、請求項２に記載の寿命判定装置。     The harmonic component includes a second current having a frequency M times that of the switching frequency, where M is a natural number different from N.
    The amplitude detection unit further detects the amplitude of the second current based on the frequency distribution obtained by the frequency analysis unit.
    The determination unit includes the third amplitude of the second current detected by the amplitude detection unit at the start of use of the capacitor and the fourth amplitude of the second current detected this time by the amplitude detection unit. The life determination device according to claim 2, wherein the capacitor is compared and it is determined whether or not the life of the capacitor has reached the end of the life of the capacitor based on the comparison result and the comparison result of the first and second amplitudes.
  7. 　Ｎは１であり、Ｍは２である、請求項６に記載の寿命判定装置。 The life determination device according to claim 6, wherein N is 1 and M is 2.
  8. 　前記判定部によって前記コンデンサの寿命が到来したと判定された場合に、その旨を報知する報知部をさらに備える、請求項１に記載の寿命判定装置。 The life determination device according to claim 1, further comprising a notification unit for notifying when the determination unit determines that the life of the capacitor has reached the end.
  9. 　直流電源から供給される直流電力を交流電力に変換する第１の電力変換器と、
    　前記第１の電力変換器の交流端子と負荷の間に接続される交流フィルタと、
    　前記交流フィルタに含まれるコンデンサの寿命を判定する寿命判定装置とを備え、
    　前記寿命判定装置は、
    　前記第１の電力変換器の運転時に前記コンデンサに流れる電流を検出する電流検出部と、
    　前記電流検出部によって検出される電流のうちの高調波成分を検出する高調波検出部と、
    　前記コンデンサの使用開始時に前記高調波検出部によって検出された高調波成分と前記高調波検出部によって今回検出された高調波成分とを比較し、その比較結果に基づいて前記コンデンサの寿命が到来したか否かを判定する判定部とを含む、電源装置。     A first power converter that converts DC power supplied from a DC power source to AC power,
    An AC filter connected between the AC terminal of the first power converter and the load,
    A life determination device for determining the life of the capacitor included in the AC filter is provided.
    The life determination device is
    A current detector that detects the current flowing through the capacitor during operation of the first power converter, and
    A harmonic detection unit that detects a harmonic component of the current detected by the current detection unit, and a harmonic detection unit.
    The harmonic component detected by the harmonic detection unit at the start of use of the capacitor is compared with the harmonic component detected this time by the harmonic detection unit, and the life of the capacitor has come to an end based on the comparison result. A power supply device including a determination unit for determining whether or not.
  10. 　前記交流フィルタはリアクトルおよび前記コンデンサを含み、
    　前記リアクトルの一方端子は前記第１の電力変換器の交流端子に接続され、前記リアクトルの他方端子は前記負荷に接続され、
    　前記コンデンサは、前記リアクトルの他方端子に接続されている、請求項９に記載の電源装置。     The AC filter includes the reactor and the capacitor.
    One terminal of the reactor is connected to the AC terminal of the first power converter, and the other terminal of the reactor is connected to the load.
    The power supply device according to claim 9, wherein the capacitor is connected to the other terminal of the reactor.
  11. 　前記電流検出部は、
    　前記リアクトルに流れる電流を検出する第１の電流検出器と、
    　負荷電流を検出する第２の電流検出器と、
    　前記第１および第２の電流検出器の検出値の差に基づいて前記コンデンサに流れる電流を求める演算部とを含む、請求項１０に記載の電源装置。     The current detector is
    A first current detector that detects the current flowing through the reactor, and
    A second current detector that detects the load current, and
    The power supply device according to claim 10, further comprising an arithmetic unit for obtaining a current flowing through the capacitor based on a difference between the detected values of the first and second current detectors.
  12. 　前記直流電源は、交流電源から供給される交流電力を直流電力に変換して前記第１の電力変換器に与える第２の電力変換器を含む、請求項９に記載の電源装置。 The power supply device according to claim 9, wherein the DC power supply includes a second power converter that converts AC power supplied from the AC power supply into DC power and supplies the AC power to the first power converter.
  13. 　前記交流電源の健全時には、前記第２の電力変換器によって生成される直流電力を電力貯蔵装置に蓄え、前記交流電源の停電時には、前記電力貯蔵装置の直流電力を前記第１の電力変換器に与える第３の電力変換器をさらに備える、請求項１２に記載の電源装置。 When the AC power supply is sound, the DC power generated by the second power converter is stored in the power storage device, and when the AC power supply fails, the DC power of the power storage device is stored in the first power converter. 12. The power supply according to claim 12, further comprising a third power converter to provide.
PCT/JP2020/047722 2020-12-21 2020-12-21 End of life determination device and power supply device equipped with same WO2022137291A1 (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3265410B2 (en) * 1993-10-27 2002-03-11 株式会社日立製作所 Power converter
JP3661155B2 (en) * 2003-02-07 2005-06-15 エイテック株式会社 Harmonic diagnosis method for electrical equipment

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3265410B2 (en) * 1993-10-27 2002-03-11 株式会社日立製作所 Power converter
JP3661155B2 (en) * 2003-02-07 2005-06-15 エイテック株式会社 Harmonic diagnosis method for electrical equipment

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