WO2020104064A1 - Dc-dc converter, bi-directional dc-dc converter, and uninterrupted power supply comprising same - Google Patents

Dc-dc converter, bi-directional dc-dc converter, and uninterrupted power supply comprising same

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Publication number
WO2020104064A1
WO2020104064A1 PCT/EP2019/025409 EP2019025409W WO2020104064A1 WO 2020104064 A1 WO2020104064 A1 WO 2020104064A1 EP 2019025409 W EP2019025409 W EP 2019025409W WO 2020104064 A1 WO2020104064 A1 WO 2020104064A1
Authority
WO
WIPO (PCT)
Prior art keywords
switching tube
diode
converter
insulated gate
gate bipolar
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/EP2019/025409
Other languages
French (fr)
Inventor
Hualiang Li
Huafen Ouyang
Dawei Zheng
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eaton Intelligent Power Ltd
Original Assignee
Eaton Intelligent Power Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Eaton Intelligent Power Ltd filed Critical Eaton Intelligent Power Ltd
Publication of WO2020104064A1 publication Critical patent/WO2020104064A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • 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
    • H02M3/00—Conversion of DC power input into DC power output
    • H02M3/02—Conversion of DC power input into DC power output without intermediate conversion into AC
    • H02M3/04—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters
    • H02M3/10—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • 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
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries
    • H02J7/90—Regulation of charging or discharging current or voltage
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
    • H02J9/061—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems for DC powered loads
    • 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
    • H02M1/00—Details of apparatus for conversion
    • H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
    • H02M1/4208—Arrangements for improving power factor of AC input
    • 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
    • H02M3/00—Conversion of DC power input into DC power output
    • H02M3/02—Conversion of DC power input into DC power output without intermediate conversion into AC
    • H02M3/04—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters
    • H02M3/10—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • H02M3/158—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
    • 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
    • H02M3/00—Conversion of DC power input into DC power output
    • H02M3/02—Conversion of DC power input into DC power output without intermediate conversion into AC
    • H02M3/04—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters
    • H02M3/10—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • H02M3/158—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
    • H02M3/1582—Buck-boost converters
    • 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
    • H02M5/00—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases
    • H02M5/40—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC
    • H02M5/42—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters
    • H02M5/44—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC
    • H02M5/453—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M5/458—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Definitions

  • the present invention relates to the field of electronic circuits, and in particular, to a DC-DC converter, a bi-directional DC-DC converter, and an uninterrupted power supply including the same.
  • a DC-DC converter is an electrical device widely used in an uninterrupted power supply.
  • An input terminal of the DC-DC converter is connected to a rechargeable battery, and an output terminal of the DC-DC converter is connected to positive and negative direct-current buses in the uninterrupted power supply.
  • the DC-DC converter boosts the direct current in the rechargeable battery and then outputs it to the positive and negative direct-current buses.
  • FIG. 1 is a circuit diagram of a first Boost-Buck converter in the prior art connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a charging mode.
  • the Boost-Buck converter 1 includes an insulated gate bipolar transistor T11 , a diode D13, and an inductor L1 , where an emitter of the insulated gate bipolar transistor T11 is connected to one terminal of the inductor L1 and a cathode of the diode D13, a collector of the insulated gate bipolar transistor T11 and the other terminal of the inductor L1 are respectively connected to a positive direct- current bus 11 and a negative direct-current bus 12, and an anode of the diode D13 and the other terminal of the inductor L1 are respectively connected to a negative electrode and a positive electrode of a rechargeable battery B.
  • a control device (not shown in FIG. 1 ) provides a pulse-width modulation signal to a gate (namely, a control terminal) of the insulated gate bipolar transistor T11 , so as to charge the rechargeable battery B using electric energy in a capacitor between the positive direct-current bus 11 and the negative direct- current bus 12 (namely, electric energy on the direct-current buses).
  • the Boost-Buck converter 1 shown in FIG. 1 can only be controlled to transmit electric energy on the direct-current buses to the rechargeable battery B, and cannot transmit electric energy in the rechargeable battery B to the capacitor between the positive and negative direct-current buses, and thus cannot achieve bi-directional energy transmission. In order to achieve bi directional energy transmission, costs of circuit modules of the uninterrupted power supply will be increased.
  • FIG. 2 is a circuit diagram of two uninterrupted power supplies including the Boost-Buck converter shown in FIG. 1 that are connected in parallel.
  • a positive electrode of a rechargeable battery B is connected to negative direct-current buses of the two uninterrupted power supplies simultaneously.
  • each control device (not shown in FIG. 2) cannot independently control the voltage on a negative direct-current bus of a corresponding uninterrupted power supply.
  • the Boost- Buck converter 1 cannot be used in a plurality of uninterrupted power supplies connected in parallel.
  • FIG. 3 is a circuit diagram of a second Boost-Buck converter in the prior art connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a discharging mode.
  • the Boost-Buck converter 2 includes an insulated gate bipolar transistor T23, a diode D21 , and an inductor L2.
  • An anode of the diode D21 is connected to one terminal of the inductor L2 and a collector of the insulated gate bipolar transistor T23, a cathode of the diode D21 and the other terminal of the inductor L2 are respectively connected to a positive direct-current bus 21 and a negative direct-current bus 22, and an emitter of the insulated gate bipolar transistor T23 and the other terminal of the inductor L2 are respectively connected to a negative electrode and a positive electrode of a rechargeable battery B.
  • a control device (not shown in FIG. 3) provides a pulse-width modulation signal to a gate of the insulated gate bipolar transistor T23, so that the rechargeable battery B discharges and stores electricity in a capacitor between the positive direct-current bus 21 and the negative direct-current bus 22.
  • the Boost-Buck converter 2 shown in FIG. 3 can only be controlled to transmit electric energy in the rechargeable battery B to the capacitor between the positive and negative direct-current buses, and cannot transmit electric energy in the capacitor between the positive and negative direct- current buses to the rechargeable battery B, and thus cannot achieve bi directional energy transmission. In order to achieve bi-directional energy transmission, costs of circuit modules of the uninterrupted power supply will be increased.
  • FIG. 4 is a circuit diagram of two uninterrupted power supplies, including the Boost-Buck converter shown in FIG. 3, that are connected in parallel.
  • a positive electrode of a rechargeable battery B is connected to negative direct-current buses of the two uninterrupted power supplies simultaneously.
  • each control device (not shown in FIG. 4) also cannot independently control the voltage on a negative direct-current bus of a corresponding uninterrupted power supply.
  • the Boost-Buck converter 2 cannot be used in a plurality of uninterrupted power supplies connected in parallel.
  • the present invention provides a DC-DC converter, comprising:
  • a first diode and a second diode wherein a cathode of the first diode and an anode of the second diode are respectively connected to two terminals of the inductor.
  • the first switching tube, the inductor and the second switching tube form a first current path; when both the first switching tube and the second switching tube are turned off, the first diode, the inductor, and the second diode form a second current path.
  • the first switching tube is a first insulated gate bipolar transistor, and an emitter of the first insulated gate bipolar transistor is connected to the cathode of the first diode; and the second switching tube is a second insulated gate bipolar transistor, and a collector of the second insulated gate bipolar transistor is connected to the anode of the second diode, wherein a collector of the first insulated gate bipolar transistor and an emitter of the second insulated gate bipolar transistor are respectively used for connecting to a positive electrode and a negative electrode of a first direct-current power supply device; and a cathode of the second diode and an anode of the first diode are respectively used for connecting to a positive electrode and a negative electrode of a second direct-current power supply device.
  • the DC-DC converter further comprises:
  • the DC-DC converter further comprises a control device for providing the same pulse-width modulation signal to the first switching tube and the second switching tube, so that the first switching tube is alternately turned on and off and the second switching tube is alternately turned on and off.
  • the DC-DC converter further comprises a control device for controlling both the third switching tube and the fourth switching tube to turn off, and providing the same pulse-width modulation signal to the first switching tube and the second switching tube, so that the first switching tube is alternately turned on and off and the second switching tube is alternately turned on and off; or
  • the present invention further provides a bi-directional DC-DC converter, comprising:
  • a first switching tube having a first diode that is anti-parallel
  • an inductor wherein one terminal of the inductor is connected to an anode of the first diode and a cathode of the second diode, and the other terminal of the inductor serves as a common terminal.
  • the first switching tube is a first insulated gate bipolar transistor
  • the second switching tube is a second insulated gate bipolar transistor
  • one terminal of the inductor is connected to an emitter of the first insulated gate bipolar transistor and a collector of the second insulated gate bipolar transistor, wherein a collector of the first insulated gate bipolar transistor and the other terminal of the inductor are respectively used for connecting to a positive electrode and a negative electrode of a first direct- current power supply device, and an emitter of the second insulated gate bipolar transistor and the other terminal of the inductor are respectively used for connecting to a negative electrode and a positive electrode of a second direct-current power supply device.
  • the bi-directional DC-DC converter further comprises: a third switching tube having a third diode that is anti-parallel; and a fourth switching tube having a fourth diode that is anti-parallel, wherein
  • a cathode of the third diode and an anode of the fourth diode are connected to the other terminal of the inductor.
  • a cathode of the first diode and an anode of the third diode are respectively used for connecting to a positive electrode and a negative electrode of a first direct-current power supply device
  • an anode of the second diode and a cathode of the fourth diode are respectively used for connecting to a negative electrode and a positive electrode of a second direct- current power supply device.
  • the DC-DC converter further comprises a control device for controlling the second switching tube to turn off, and providing a pulse- width modulation signal to the first switching tube so that the first switching tube is alternately turned on and off; or
  • the DC-DC converter further comprises a control device for controlling the second switching tube and the fourth switching tube to turn off, and providing the same pulse-width modulation signal to the first switching tube and the third switching tube, so that the first switching tube is alternately turned on and off and the third switching tube is alternately turned on and off; or
  • the present invention further provides an uninterrupted power supply, comprising:
  • a power factor correction circuit wherein an input terminal of the power factor correction circuit is used for connecting to an alternating-current power supply, and an output terminal of the power factor correction circuit is connected to the positive and negative direct-current buses;
  • an inverter wherein an input terminal of the inverter is connected to the positive and negative direct-current buses, and an output terminal of the inverter is used for providing an alternating current.
  • the DC-DC converter of the present invention can buck or boost charge a rechargeable battery, or cause the rechargeable battery to buck or boost discharge, and can be used in uninterrupted power supplies connected in parallel.
  • the bi-directional DC-DC converter of the present invention can also achieve bi-directional energy transmission.
  • FIG. 1 is a circuit diagram of a first Boost-Buck converter in the prior art connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a charging mode.
  • FIG. 2 is a circuit diagram of two uninterrupted power supplies, including the Boost-Buck converter shown in FIG. 1 , that are connected in parallel.
  • FIG. 3 is a circuit diagram of a second Boost-Buck converter in the prior art connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a discharging mode.
  • FIG. 4 is a circuit diagram of two uninterrupted power supplies, including the Boost-Buck converter shown in FIG. 3, that are connected in parallel.
  • FIG. 5 is a circuit diagram of a DC-DC converter according to a first embodiment of the present invention.
  • FIG. 6 is a circuit diagram of the DC-DC converter shown in FIG. 5 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a charging mode.
  • FIG. 7 is a circuit diagram of the DC-DC converter shown in FIG. 5 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a discharging mode.
  • FIG. 8 is a circuit diagram of two uninterrupted power supplies, including the DC-DC converter shown in FIG. 6, that are connected in parallel.
  • FIG. 9 is a circuit diagram of two uninterrupted power supplies, including the DC-DC converter shown in FIG. 7, that are connected in parallel.
  • FIG. 10 is a circuit diagram of a DC-DC converter according to a second embodiment of the present invention.
  • FIG. 11 is a circuit diagram of the DC-DC converter shown in FIG. 10 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery.
  • FIG. 12 is an equivalent circuit diagram of the DC-DC converter shown in FIG. 11 in a charging mode.
  • FIG. 13 is an equivalent circuit diagram of the DC-DC converter shown in FIG. 11 in a discharging mode.
  • FIG. 14 is a circuit diagram of two uninterrupted power supplies, including the DC-DC converter shown in FIG. 10, that are connected in parallel.
  • FIG. 15 is a circuit diagram of a bi-directional DC-DC converter according to a third embodiment of the present invention.
  • FIG. 16 is a circuit diagram of the bi-directional DC-DC converter shown in FIG. 15 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery.
  • FIG. 17 is an equivalent circuit diagram of the bi-directional DC-DC converter shown in FIG. 16 in a charging mode.
  • FIG. 18 is an equivalent circuit diagram of the bi-directional DC-DC converter shown in FIG. 16 in a discharging mode.
  • FIG. 19 is a circuit diagram of a bi-directional DC-DC converter according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
  • FIG. 5 is a circuit diagram of a DC-DC converter according to a first embodiment of the present invention.
  • the DC-DC converter 3 includes an insulated gate bipolar transistor T31 , an inductor L3, and an insulated gate bipolar transistor T32 connected in sequence, and a diode D33 and a diode D34 connected to two terminals of the inductor L3.
  • One terminal of the inductor L3 is connected to a node formed by connecting an emitter of the insulated gate bipolar transistor T31 and a cathode of the diode D33, and the other terminal of the inductor L3 is connected to a node formed by connecting a collector of the insulated gate bipolar transistor T32 and an anode of the diode D34.
  • a collector of the insulated gate bipolar transistor T31 and an emitter of the insulated gate bipolar transistor T32 are respectively used for connecting to a positive electrode and a negative electrode of a direct-current power supply device (for example, a capacitor or a rechargeable battery), and a cathode of the diode D34 and an anode of the diode D33 respectively serve as a positive output terminal and a negative output terminal of the DC-DC converter 3 and are used for connecting to a positive electrode and a negative electrode of another direct-current power supply device (for example, a capacitor or a rechargeable battery).
  • a direct-current power supply device for example, a capacitor or a rechargeable battery
  • FIG. 6 is a circuit diagram of the DC-DC converter shown in FIG. 5 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a charging mode.
  • a positive electrode and a negative electrode of a rechargeable battery B are respectively connected to the cathode of the diode D34 and the anode of the diode D33, and the collector of the insulated gate bipolar transistor T31 and the emitter of the insulated gate bipolar transistor T32 are respectively connected to a positive direct-current bus 31 and a negative direct-current bus 32.
  • a control device (not shown in FIG. 6) provides the same pulse-width modulation signal to gates of the insulated gate bipolar transistors T31 and T32, so that the insulated gate bipolar transistor T31 is alternately turned on and off and the insulated gate bipolar transistor T32 is alternately turned on and off.
  • the insulated gate bipolar transistors T31 and T32 are turned on, the positive direct-current bus 31 , the insulated gate bipolar transistor T31 , the inductor L3, the insulated gate bipolar transistor T32, and the negative direct- current bus 32 form a current path, and the current direction thereof is indicated by the dashed single-headed arrow in FIG. 6.
  • the current in the inductor L3 rises, and the inductor L3 stores energy.
  • the insulated gate bipolar transistors T31 and T32 are turned off, the negative electrode of the rechargeable battery B, the diode D33, the inductor L3, the diode D34, and the positive electrode of the rechargeable battery B form another current path, and the current direction thereof is indicated by the dashed double-headed arrow in FIG. 6.
  • the current in the inductor L3 decreases, and the inductor L3 releases and stores energy in the rechargeable battery B, thereby realizing charging of the rechargeable battery B.
  • an inductance value of the inductor L3 is L
  • a value of the current in the inductor L3 is i L
  • a voltage value of the inductor L3 is UL
  • a value of the voltage between the positive and negative direct-current buses is Udc
  • a voltage value of the rechargeable battery B is Uo
  • a period of the pulse- width modulation signal is T
  • a duty cycle of the pulse-width modulation signal is d
  • an on time and an off time of the insulated gate bipolar transistor T31 or T32 in one pulse-width modulation signal period are respectively Ton and Toff.
  • the current in the inductor L3 is equal at an initial moment (namely, 0) of a switching period and an end moment (namely, T) of the switching period.
  • FIG. 7 is a circuit diagram of the DC-DC converter shown in FIG. 5 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a discharging mode.
  • a positive electrode and a negative electrode of a rechargeable battery B are respectively connected to the collector of the insulated gate bipolar transistor T31 and the emitter of the insulated gate bipolar transistor T32, the cathode of the diode D34 is connected to a positive direct-current bus 31 , and the anode of the diode D33 is connected to a negative direct-current bus 32.
  • a control device (not shown in FIG. 7) provides the same pulse-width modulation signal to gates of the insulated gate bipolar transistors T31 and T32, so that the insulated gate bipolar transistor T31 is alternately turned on and off and the insulated gate bipolar transistor T32 is alternately turned on and off.
  • the insulated gate bipolar transistors T31 and T32 When the insulated gate bipolar transistors T31 and T32 are turned on, the positive electrode of the rechargeable battery B, the insulated gate bipolar transistor T31 , the inductor L3, the insulated gate bipolar transistor T32, and the negative electrode of the rechargeable battery B form a current path, and the current direction thereof is indicated by the dashed single-headed arrow in FIG. 7. At this time, the current in the inductor L3 rises, and the inductor L3 stores energy.
  • the negative direct-current bus 32, the diode D33, the inductor L3, the diode D34, and the positive direct-current bus 31 form another current path, and the current direction thereof is indicated by the dashed double-headed arrow in FIG. 7.
  • the current in the inductor L3 decreases, and the inductor L3 releases and stores energy in a capacitor between the positive and negative direct-current buses.
  • the rechargeable battery B discharges and stores electricity in the capacitor between the positive and negative direct-current buses.
  • an inductance value of the inductor L3 is L
  • a value of the current in the inductor L3 is i L
  • a voltage value of the inductor L3 is U L
  • a value of the voltage between the positive and negative direct-current buses is Udc
  • a voltage value of the rechargeable battery B is Uo
  • a period of the pulse- width modulation signal is T
  • a duty cycle of the pulse-width modulation signal is d
  • an on time and an off time of the insulated gate bipolar transistor T31 in one pulse-width modulation signal period are respectively Ton and Toff.
  • the current in the inductor L3 is equal at an initial moment (namely, 0) of a switching period and an end moment (namely, T) of the switching period.
  • FIG. 8 is a circuit diagram of two uninterrupted power supplies, including the DC-DC converter shown in FIG. 6, that are connected in parallel.
  • a negative direct-current bus of each uninterrupted power supply is connected to a positive electrode of a rechargeable battery B through an insulated gate bipolar transistor and a diode in sequence, negative direct- current buses of the plurality of uninterrupted power supplies are isolated from each other, and each control device (not shown in FIG. 8) can independently control the voltage on a negative direct-current bus of a corresponding uninterrupted power supply, so as to charge the rechargeable battery B using electric energy in a capacitor between the positive and negative direct-current buses of the uninterrupted power supply.
  • FIG. 9 is a circuit diagram of two uninterrupted power supplies, including the DC-DC converter shown in FIG. 7, that are connected in parallel.
  • a negative direct-current bus of each uninterrupted power supply is connected to a positive electrode of a rechargeable battery B through a diode and an insulated gate bipolar transistor in sequence, negative direct- current buses of the plurality of uninterrupted power supplies are isolated from each other, and each control device (not shown in FIG. 9) can independently control the voltage on a negative direct-current bus of a corresponding uninterrupted power supply, so that the rechargeable battery B discharges and stores electricity in a capacitor between the positive and negative direct- current buses of the corresponding uninterrupted power supply.
  • the DC-DC converter 4 differs from the DC-DC converter 3 shown in FIG. 5 in that the DC- DC converter 4 further includes diodes D41 and D42 respectively connected in anti-parallel to insulated gate bipolar transistors T41 and T42; and insulated gate bipolar transistors T43 and T44 respectively connected in anti-parallel to diodes D43 and D44.
  • a cathode of the diode D41 and an anode of the diode D42 are respectively used for connecting to a positive electrode and a negative electrode of a direct-current power supply device (for example, a capacitor or a rechargeable battery), and a cathode of the diode D44 and an anode of the diode D43 respectively serve as a positive output terminal and a negative output terminal of the DC-DC converter 4 and are used for connecting to a positive electrode and a negative electrode of another direct-current power supply device (for example, a capacitor or a rechargeable battery).
  • a direct-current power supply device for example, a capacitor or a rechargeable battery
  • a cathode of the diode D44 and an anode of the diode D43 are respectively used for connecting to a positive electrode and a negative electrode of a direct- current power supply device (for example, a capacitor or a rechargeable battery), and a cathode of the diode D41 and an anode of the diode D42 respectively serve as a positive output terminal and a negative output terminal of the DC-DC converter 4 and are used for connecting to a positive electrode and a negative electrode of another direct-current power supply device (for example, a capacitor or a rechargeable battery).
  • a direct- current power supply device for example, a capacitor or a rechargeable battery
  • FIG. 11 is a circuit diagram of the DC-DC converter shown in FIG. 10 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery.
  • a collector of the insulated gate bipolar transistor T41 and the cathode of the diode D41 are connected to a positive direct-current bus 41
  • an emitter of the insulated gate bipolar transistor T42 and the anode of the diode D42 are connected to a negative direct-current bus 42
  • an emitter of the insulated gate bipolar transistor T43 and the anode of the diode D43 are connected to a negative electrode of the rechargeable battery B
  • a collector of the insulated gate bipolar transistor T43 and the cathode of the diode D44 are connected to a positive electrode of the rechargeable battery B.
  • a control device (not shown in FIG. 11 ) controls the insulated gate bipolar transistors T43 and T44 to turn off, and provides the same pulse-width modulation signal to gates of the insulated gate bipolar transistors T41 and T42, so that the insulated gate bipolar transistor T41 is alternately turned on and off and the insulated gate bipolar transistor T42 is alternately turned on and off.
  • FIG. 12 is an equivalent circuit diagram of the DC-DC converter shown in FIG. 11 in a charging mode, which is the same as the circuit shown in FIG. 6. While the specific charging and discharging process is not described herein again, and buck charging or boost charging of the rechargeable battery B can also be achieved.
  • a control device (not shown in FIG. 11 ) controls the insulated gate bipolar transistors T41 and T42 to turn off, and provides the same pulse-width modulation signal to gates of the insulated gate bipolar transistors T43 and T44, so that the insulated gate bipolar transistor T43 is alternately turned on and off and the insulated gate bipolar transistor T44 is alternately turned on and off.
  • FIG. 13 is an equivalent circuit diagram of the DC-DC converter shown in FIG. 11 in a discharging mode, which is the same as the circuit shown in FIG. 7. While the specific charging and discharging process is not described herein again, and boost discharging or buck discharging of the rechargeable battery B can also be achieved.
  • the DC-DC converter 4 is a bi-directional DC-DC converter and does not need to be additionally connected to a charger or a direct-current converter, thereby saving costs.
  • Boost discharging or buck discharging of the rechargeable battery B can be achieved, and buck charging or boost charging of the rechargeable battery B can also be achieved.
  • a duty cycle of a pulse-width modulation signal is changed so that a capacitor between positive and negative direct-current buses can be deeply discharged and charge the rechargeable battery B at a voltage of approximately 0 volt without producing any impact current.
  • FIG. 14 is a circuit diagram of two uninterrupted power supplies, including the DC-DC converter shown in FIG. 10, that are connected in parallel.
  • Each control device (not shown in FIG. 14) can also separately control a DC- DC converter in a corresponding uninterrupted power supply so as to independently control the voltage on a negative direct-current bus of each uninterrupted power supply.
  • FIG. 15 is a circuit diagram of a bi-directional DC-DC converter according to a third embodiment of the present invention.
  • the bi-directional DC-DC converter 5 includes an insulated gate bipolar transistor T51 having a diode that is anti-parallel D51 , an insulated gate bipolar transistor T53 having a diode that is anti-parallel D53, and an inductor L5.
  • a terminal 55 of the inductor L5 is connected to a node formed by connecting an anode of the diode D51 and a cathode of the diode D53, and a terminal 56 of the inductor L5 serves as a common terminal.
  • a cathode of the diode D51 namely, a collector of the insulated gate bipolar transistor T51
  • the terminal 56 of the inductor L5 are respectively used for connecting to a positive electrode and a negative electrode of a direct- current power supply device (for example, a capacitor or a rechargeable battery)
  • the terminal 56 of the inductor L5 and an anode of the diode D53 respectively serve as a positive output terminal and a negative output terminal of the bi directional DC-DC converter 5 and are used for connecting to a positive electrode and a negative electrode of another direct-current power supply device (for example, a capacitor or a rechargeable battery).
  • the terminal 56 of the inductor L5 and an anode of the diode D53 are respectively used for connecting to a positive electrode and a negative electrode of a direct-current power supply device (for example, a capacitor or a rechargeable battery), and a cathode of the diode D51 and the terminal 56 of the inductor L5 respectively serve as a positive output terminal and a negative output terminal of the bi directional DC-DC converter 5 and are used for connecting to a positive electrode and a negative electrode of another direct-current power supply device (for example, a capacitor or a rechargeable battery).
  • a direct-current power supply device for example, a capacitor or a rechargeable battery
  • FIG. 16 is a circuit diagram of the bi-directional DC-DC converter shown in FIG. 15 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery.
  • the collector of the insulated gate bipolar transistor T51 and the cathode of the diode D51 are connected to a positive direct-current bus 51
  • the emitter of the insulated gate bipolar transistor T53 and the anode of the diode D53 are connected to a negative electrode of the rechargeable battery B
  • both a positive electrode of the rechargeable battery B and the terminal 56 of the inductor L5 are connected to a negative direct-current bus 52.
  • FIG. 17 is an equivalent circuit diagram of the bi-directional DC-DC converter shown in FIG. 16 in a charging mode. As shown in FIG. 17, when the insulated gate bipolar transistor T51 is turned on, the positive direct-current bus 51 , the insulated gate bipolar transistor T51 , the inductor L5, and the negative direct- current bus 52 form a current path, and the current direction thereof is indicated by the dashed single-headed arrow in FIG. 17.
  • the inductor L5 stores energy.
  • the inductor L5 When the insulated gate bipolar transistor T51 is turned off, the inductor L5, the rechargeable battery B, and the diode D53 form a current path, and the current direction thereof is indicated by the dashed double-headed arrow in FIG. 17. At this time, the inductor L5 releases energy and charges the rechargeable battery B.
  • an inductance value of the inductor L5 is L
  • a value of the current in the inductor L5 is i L
  • a voltage value of the inductor L5 is U L
  • a value of the voltage between the positive and negative direct-current buses is Udc
  • a voltage value of the rechargeable battery B is Uo
  • a period of the pulse- width modulation signal is T
  • a duty cycle of the pulse-width modulation signal is d
  • an on time and an off time of the insulated gate bipolar transistor T51 in one pulse-width modulation signal period are respectively Ton and Toff.
  • the current in the inductor L5 is equal at an initial moment (namely, 0) of a switching period and an end moment (namely, T) of the switching period.
  • FIG. 18 is an equivalent circuit diagram of the bi-directional DC-DC converter shown in FIG. 16 in a discharging mode. As shown in FIG. 18, when the insulated gate bipolar transistor T53 is turned on, the rechargeable battery B, the inductor L5, and the insulated gate bipolar transistor T53 form a current path, and the current direction thereof is indicated by the dashed single-headed arrow in FIG. 18.
  • the inductor L5 stores energy.
  • the negative direct-current bus 52, the inductor L5, the diode D51 , and the positive direct-current bus 51 form another current path, and the current direction thereof is indicated by the dashed double-headed arrow in FIG. 18.
  • the inductor L5 releases and stores energy in a capacitor between the positive direct-current bus 51 and the negative direct-current bus 52.
  • an inductance value of the inductor L5 is L
  • a value of the current in the inductor L5 is i L
  • a voltage value of the inductor L5 is U L
  • a value of the voltage between the positive and negative direct-current buses is Udc
  • a voltage value of the rechargeable battery B is Uo
  • a period of the pulse- width modulation signal is T
  • a duty cycle of the pulse-width modulation signal is d
  • an on time and an off time of the insulated gate bipolar transistor T53 in one pulse-width modulation signal period are respectively Ton and Toff.
  • the current in the inductor L5 is equal at an initial moment (namely, 0) of a switching period and an end moment (namely, T) of the switching period.
  • the bi-directional DC-DC converter 5 can controllably transmit electric energy in the capacitor between the positive and negative direct-current buses to the rechargeable battery B, and can also transmit electric energy in the rechargeable battery B to the capacitor between the positive and negative direct-current buses, thereby achieving bi-directional energy transmission.
  • FIG. 19 is a circuit diagram of a bi-directional DC-DC converter according to a fourth embodiment of the present invention.
  • the bi-directional DC-DC converter 6 differs from the bi-directional DC-DC converter 5 shown in FIG. 15 in that the bi-directional DC-DC converter 6 further includes an insulated gate bipolar transistor T62 having a diode that is anti-parallel D62 and an insulated gate bipolar transistor T64 having a diode that is anti-parallel D64, where a cathode of the diode D62 and an anode of the diode D64 are connected to a terminal 66 of an inductor L6.
  • the bi-directional DC-DC converter 6 in this embodiment has the same topology structure as that of the DC-DC converter 4 in FIG. 10, and the operating principle thereof will not be described herein again.
  • the bi-directional DC-DC converter 6 can also be used in a plurality of uninterrupted power supplies connected in parallel.
  • a switching tube such as a metal-oxide-semiconductor field effect transistor (MOSFET) is used in place of the insulated gate bipolar transistor in the aforementioned embodiment.
  • MOSFET metal-oxide-semiconductor field effect transistor
  • the present invention further provides an uninterrupted power supply, which includes the DC-DC converter or bi-directional DC-DC converter in the aforementioned embodiment of the present invention, a power factor correction circuit (PFC) and an inverter, where the DC-DC converter or the bi- directional DC-DC converter is connected between positive and negative direct-current buses and a rechargeable battery, an input terminal of the PFC is connected to an alternating-current power supply (for example, a mains supply), an output terminal of the PFC is connected to the positive and negative direct-current buses, an input terminal of the inverter is connected to the positive and negative direct-current buses, and an output terminal of the inverter is used for providing an alternating current to a load.
  • alternating-current power supply for example, a mains supply
  • an output terminal of the PFC is connected to the positive and negative direct-current buses
  • an input terminal of the inverter is connected to the positive and negative direct-current buses
  • an output terminal of the inverter is used for providing an alternating current to a load.

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Abstract

The present invention provides a DC-DC converter, a bi-directional DC-DC converter, and an uninterrupted power supply including the same. The DC-DC converter comprises a first switching tube, an inductor, and a second switching tube connected in sequence; and a first diode and a second diode, wherein a cathode of the first diode and an anode of the second diode are respectively connected to two terminals of the inductor. The DC-DC converter of the present invention can buck or boost charge a rechargeable battery, or cause the rechargeable battery to buck or boost discharge, and can be used in uninterrupted power supplies connected in parallel.

Description

DC-DC CONVERTER, BI-DIRECTIONAL DC-DC CONVERTER, AND UNINTERRUPTED POWER SUPPLY COMPRISING SAME
TECHNICAL FIELD
[0001] The present invention relates to the field of electronic circuits, and in particular, to a DC-DC converter, a bi-directional DC-DC converter, and an uninterrupted power supply including the same.
BACKGROUND
[0002] A DC-DC converter is an electrical device widely used in an uninterrupted power supply. An input terminal of the DC-DC converter is connected to a rechargeable battery, and an output terminal of the DC-DC converter is connected to positive and negative direct-current buses in the uninterrupted power supply. When a mains supply fails, the DC-DC converter boosts the direct current in the rechargeable battery and then outputs it to the positive and negative direct-current buses.
[0003] FIG. 1 is a circuit diagram of a first Boost-Buck converter in the prior art connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a charging mode. As shown in FIG. 1 , the Boost-Buck converter 1 includes an insulated gate bipolar transistor T11 , a diode D13, and an inductor L1 , where an emitter of the insulated gate bipolar transistor T11 is connected to one terminal of the inductor L1 and a cathode of the diode D13, a collector of the insulated gate bipolar transistor T11 and the other terminal of the inductor L1 are respectively connected to a positive direct- current bus 11 and a negative direct-current bus 12, and an anode of the diode D13 and the other terminal of the inductor L1 are respectively connected to a negative electrode and a positive electrode of a rechargeable battery B. A control device (not shown in FIG. 1 ) provides a pulse-width modulation signal to a gate (namely, a control terminal) of the insulated gate bipolar transistor T11 , so as to charge the rechargeable battery B using electric energy in a capacitor between the positive direct-current bus 11 and the negative direct- current bus 12 (namely, electric energy on the direct-current buses).
[0004] The Boost-Buck converter 1 shown in FIG. 1 can only be controlled to transmit electric energy on the direct-current buses to the rechargeable battery B, and cannot transmit electric energy in the rechargeable battery B to the capacitor between the positive and negative direct-current buses, and thus cannot achieve bi-directional energy transmission. In order to achieve bi directional energy transmission, costs of circuit modules of the uninterrupted power supply will be increased.
[0005] In practical application of the uninterrupted power supply, in order to increase power density, a plurality of uninterrupted power supply power modules often need to be connected in parallel, where the plurality of uninterrupted power supply power modules share the rechargeable battery.
[0006] FIG. 2 is a circuit diagram of two uninterrupted power supplies including the Boost-Buck converter shown in FIG. 1 that are connected in parallel. As shown in FIG. 2, a positive electrode of a rechargeable battery B is connected to negative direct-current buses of the two uninterrupted power supplies simultaneously. As a result, each control device (not shown in FIG. 2) cannot independently control the voltage on a negative direct-current bus of a corresponding uninterrupted power supply. Thus, it can be seen that the Boost- Buck converter 1 cannot be used in a plurality of uninterrupted power supplies connected in parallel.
[0007] FIG. 3 is a circuit diagram of a second Boost-Buck converter in the prior art connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a discharging mode. As shown in FIG. 3, the Boost-Buck converter 2 includes an insulated gate bipolar transistor T23, a diode D21 , and an inductor L2. An anode of the diode D21 is connected to one terminal of the inductor L2 and a collector of the insulated gate bipolar transistor T23, a cathode of the diode D21 and the other terminal of the inductor L2 are respectively connected to a positive direct-current bus 21 and a negative direct-current bus 22, and an emitter of the insulated gate bipolar transistor T23 and the other terminal of the inductor L2 are respectively connected to a negative electrode and a positive electrode of a rechargeable battery B. A control device (not shown in FIG. 3) provides a pulse-width modulation signal to a gate of the insulated gate bipolar transistor T23, so that the rechargeable battery B discharges and stores electricity in a capacitor between the positive direct-current bus 21 and the negative direct-current bus 22.
[0008] The Boost-Buck converter 2 shown in FIG. 3 can only be controlled to transmit electric energy in the rechargeable battery B to the capacitor between the positive and negative direct-current buses, and cannot transmit electric energy in the capacitor between the positive and negative direct- current buses to the rechargeable battery B, and thus cannot achieve bi directional energy transmission. In order to achieve bi-directional energy transmission, costs of circuit modules of the uninterrupted power supply will be increased.
[0009] FIG. 4 is a circuit diagram of two uninterrupted power supplies, including the Boost-Buck converter shown in FIG. 3, that are connected in parallel. As shown in FIG. 4, a positive electrode of a rechargeable battery B is connected to negative direct-current buses of the two uninterrupted power supplies simultaneously. As a result, each control device (not shown in FIG. 4) also cannot independently control the voltage on a negative direct-current bus of a corresponding uninterrupted power supply. Thus, the Boost-Buck converter 2 cannot be used in a plurality of uninterrupted power supplies connected in parallel.
SUMMARY [0010] In view of the aforementioned technical problems existing in the prior art, the present invention provides a DC-DC converter, comprising:
a first switching tube, an inductor, and a second switching tube connected in sequence; and
a first diode and a second diode, wherein a cathode of the first diode and an anode of the second diode are respectively connected to two terminals of the inductor.
[0011 ] Preferably, when both the first switching tube and the second switching tube are turned on, the first switching tube, the inductor and the second switching tube form a first current path; when both the first switching tube and the second switching tube are turned off, the first diode, the inductor, and the second diode form a second current path.
[0012] Preferably, the first switching tube is a first insulated gate bipolar transistor, and an emitter of the first insulated gate bipolar transistor is connected to the cathode of the first diode; and the second switching tube is a second insulated gate bipolar transistor, and a collector of the second insulated gate bipolar transistor is connected to the anode of the second diode, wherein a collector of the first insulated gate bipolar transistor and an emitter of the second insulated gate bipolar transistor are respectively used for connecting to a positive electrode and a negative electrode of a first direct-current power supply device; and a cathode of the second diode and an anode of the first diode are respectively used for connecting to a positive electrode and a negative electrode of a second direct-current power supply device.
[0013] Preferably, the DC-DC converter further comprises:
a diode connected in anti-parallel to the first switching tube;
a diode connected in anti-parallel to the second switching tube;
a third switching tube connected in anti-parallel to the first diode; and a fourth switching tube connected in anti-parallel to the second diode. [0014] Preferably, the DC-DC converter further comprises a control device for providing the same pulse-width modulation signal to the first switching tube and the second switching tube, so that the first switching tube is alternately turned on and off and the second switching tube is alternately turned on and off.
[0015] Preferably, the DC-DC converter further comprises a control device for controlling both the third switching tube and the fourth switching tube to turn off, and providing the same pulse-width modulation signal to the first switching tube and the second switching tube, so that the first switching tube is alternately turned on and off and the second switching tube is alternately turned on and off; or
controlling both the first switching tube and the second switching tube to turn off, and providing the same pulse-width modulation signal to the third switching tube and the fourth switching tube, so that the third switching tube is alternately turned on and off and the fourth switching tube is alternately turned on and off.
[0016] The present invention further provides a bi-directional DC-DC converter, comprising:
a first switching tube having a first diode that is anti-parallel;
a second switching tube having a second diode that is anti-parallel; and
an inductor, wherein one terminal of the inductor is connected to an anode of the first diode and a cathode of the second diode, and the other terminal of the inductor serves as a common terminal.
[0017] Preferably, the first switching tube is a first insulated gate bipolar transistor, the second switching tube is a second insulated gate bipolar transistor, and one terminal of the inductor is connected to an emitter of the first insulated gate bipolar transistor and a collector of the second insulated gate bipolar transistor, wherein a collector of the first insulated gate bipolar transistor and the other terminal of the inductor are respectively used for connecting to a positive electrode and a negative electrode of a first direct- current power supply device, and an emitter of the second insulated gate bipolar transistor and the other terminal of the inductor are respectively used for connecting to a negative electrode and a positive electrode of a second direct-current power supply device.
[0018] Preferably, the bi-directional DC-DC converter further comprises: a third switching tube having a third diode that is anti-parallel; and a fourth switching tube having a fourth diode that is anti-parallel, wherein
a cathode of the third diode and an anode of the fourth diode are connected to the other terminal of the inductor. [0019] Preferably, a cathode of the first diode and an anode of the third diode are respectively used for connecting to a positive electrode and a negative electrode of a first direct-current power supply device, and an anode of the second diode and a cathode of the fourth diode are respectively used for connecting to a negative electrode and a positive electrode of a second direct- current power supply device.
[0020] Preferably, the DC-DC converter further comprises a control device for controlling the second switching tube to turn off, and providing a pulse- width modulation signal to the first switching tube so that the first switching tube is alternately turned on and off; or
controlling the first switching tube to turn off, and providing a pulse- width modulation signal to the second switching tube so that the second switching tube is alternately turned on and off. [0021 ] Preferably, the DC-DC converter further comprises a control device for controlling the second switching tube and the fourth switching tube to turn off, and providing the same pulse-width modulation signal to the first switching tube and the third switching tube, so that the first switching tube is alternately turned on and off and the third switching tube is alternately turned on and off; or
controlling the first switching tube and the third switching tube to turn off, and providing the same pulse-width modulation signal to the second switching tube and the fourth switching tube, so that the second switching tube is alternately turned on and off and the fourth switching tube is alternately turned on and off.
[0022] The present invention further provides an uninterrupted power supply, comprising:
the DC-DC converter described above or the bi-directional DC-DC converter described above, wherein the DC-DC converter or the bi-directional DC-DC converter is connected between positive and negative direct-current buses and a rechargeable battery;
a power factor correction circuit, wherein an input terminal of the power factor correction circuit is used for connecting to an alternating-current power supply, and an output terminal of the power factor correction circuit is connected to the positive and negative direct-current buses; and
an inverter, wherein an input terminal of the inverter is connected to the positive and negative direct-current buses, and an output terminal of the inverter is used for providing an alternating current.
[0023] The DC-DC converter of the present invention can buck or boost charge a rechargeable battery, or cause the rechargeable battery to buck or boost discharge, and can be used in uninterrupted power supplies connected in parallel. The bi-directional DC-DC converter of the present invention can also achieve bi-directional energy transmission.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Embodiments of the present invention are further described below with reference to the accompanying drawings: FIG. 1 is a circuit diagram of a first Boost-Buck converter in the prior art connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a charging mode.
FIG. 2 is a circuit diagram of two uninterrupted power supplies, including the Boost-Buck converter shown in FIG. 1 , that are connected in parallel.
FIG. 3 is a circuit diagram of a second Boost-Buck converter in the prior art connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a discharging mode.
FIG. 4 is a circuit diagram of two uninterrupted power supplies, including the Boost-Buck converter shown in FIG. 3, that are connected in parallel.
FIG. 5 is a circuit diagram of a DC-DC converter according to a first embodiment of the present invention.
FIG. 6 is a circuit diagram of the DC-DC converter shown in FIG. 5 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a charging mode.
FIG. 7 is a circuit diagram of the DC-DC converter shown in FIG. 5 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a discharging mode.
FIG. 8 is a circuit diagram of two uninterrupted power supplies, including the DC-DC converter shown in FIG. 6, that are connected in parallel.
FIG. 9 is a circuit diagram of two uninterrupted power supplies, including the DC-DC converter shown in FIG. 7, that are connected in parallel.
FIG. 10 is a circuit diagram of a DC-DC converter according to a second embodiment of the present invention.
FIG. 11 is a circuit diagram of the DC-DC converter shown in FIG. 10 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery.
FIG. 12 is an equivalent circuit diagram of the DC-DC converter shown in FIG. 11 in a charging mode.
FIG. 13 is an equivalent circuit diagram of the DC-DC converter shown in FIG. 11 in a discharging mode. FIG. 14 is a circuit diagram of two uninterrupted power supplies, including the DC-DC converter shown in FIG. 10, that are connected in parallel.
FIG. 15 is a circuit diagram of a bi-directional DC-DC converter according to a third embodiment of the present invention.
FIG. 16 is a circuit diagram of the bi-directional DC-DC converter shown in FIG. 15 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery.
FIG. 17 is an equivalent circuit diagram of the bi-directional DC-DC converter shown in FIG. 16 in a charging mode.
FIG. 18 is an equivalent circuit diagram of the bi-directional DC-DC converter shown in FIG. 16 in a discharging mode.
FIG. 19 is a circuit diagram of a bi-directional DC-DC converter according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0025] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention is further described in detail below through specific embodiments with reference to the accompanying drawings.
[0026] FIG. 5 is a circuit diagram of a DC-DC converter according to a first embodiment of the present invention. As shown in FIG. 5, the DC-DC converter 3 includes an insulated gate bipolar transistor T31 , an inductor L3, and an insulated gate bipolar transistor T32 connected in sequence, and a diode D33 and a diode D34 connected to two terminals of the inductor L3. One terminal of the inductor L3 is connected to a node formed by connecting an emitter of the insulated gate bipolar transistor T31 and a cathode of the diode D33, and the other terminal of the inductor L3 is connected to a node formed by connecting a collector of the insulated gate bipolar transistor T32 and an anode of the diode D34. [0027] A collector of the insulated gate bipolar transistor T31 and an emitter of the insulated gate bipolar transistor T32 are respectively used for connecting to a positive electrode and a negative electrode of a direct-current power supply device (for example, a capacitor or a rechargeable battery), and a cathode of the diode D34 and an anode of the diode D33 respectively serve as a positive output terminal and a negative output terminal of the DC-DC converter 3 and are used for connecting to a positive electrode and a negative electrode of another direct-current power supply device (for example, a capacitor or a rechargeable battery).
[0028] The operating principle of the DC-DC converter 3 will be described below with reference to circuit diagrams of the DC-DC converter 3 in a charging mode and a discharging mode. [0029] FIG. 6 is a circuit diagram of the DC-DC converter shown in FIG. 5 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a charging mode. As shown in FIG. 6, a positive electrode and a negative electrode of a rechargeable battery B are respectively connected to the cathode of the diode D34 and the anode of the diode D33, and the collector of the insulated gate bipolar transistor T31 and the emitter of the insulated gate bipolar transistor T32 are respectively connected to a positive direct-current bus 31 and a negative direct-current bus 32.
[0030] In the charging mode, a control device (not shown in FIG. 6) provides the same pulse-width modulation signal to gates of the insulated gate bipolar transistors T31 and T32, so that the insulated gate bipolar transistor T31 is alternately turned on and off and the insulated gate bipolar transistor T32 is alternately turned on and off. [0031 ] When the insulated gate bipolar transistors T31 and T32 are turned on, the positive direct-current bus 31 , the insulated gate bipolar transistor T31 , the inductor L3, the insulated gate bipolar transistor T32, and the negative direct- current bus 32 form a current path, and the current direction thereof is indicated by the dashed single-headed arrow in FIG. 6. At this time, the current in the inductor L3 rises, and the inductor L3 stores energy. When the insulated gate bipolar transistors T31 and T32 are turned off, the negative electrode of the rechargeable battery B, the diode D33, the inductor L3, the diode D34, and the positive electrode of the rechargeable battery B form another current path, and the current direction thereof is indicated by the dashed double-headed arrow in FIG. 6. At this time, the current in the inductor L3 decreases, and the inductor L3 releases and stores energy in the rechargeable battery B, thereby realizing charging of the rechargeable battery B.
[0032] Assume that an inductance value of the inductor L3 is L, a value of the current in the inductor L3 is i L, a voltage value of the inductor L3 is UL, a value of the voltage between the positive and negative direct-current buses is Udc, a voltage value of the rechargeable battery B is Uo, a period of the pulse- width modulation signal is T, a duty cycle of the pulse-width modulation signal is d, and an on time and an off time of the insulated gate bipolar transistor T31 or T32 in one pulse-width modulation signal period are respectively Ton and Toff.
[0033] Using one period of the pulse-width modulation signal as an example for description, the current in the inductor L3 is equal at an initial moment (namely, 0) of a switching period and an end moment (namely, T) of the switching period. The following equations are thus satisfied:
Figure imgf000013_0001
Figure imgf000014_0001
[0034] Thus, Uo/Udc=d/(1 -d). When the duty cycle d is less than 0.5, buck charging of the rechargeable battery B is achieved. When the duty cycle d is greater than 0.5, boost charging of the rechargeable battery B is achieved.
[0035] FIG. 7 is a circuit diagram of the DC-DC converter shown in FIG. 5 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery and in a discharging mode. As shown in FIG. 7, a positive electrode and a negative electrode of a rechargeable battery B are respectively connected to the collector of the insulated gate bipolar transistor T31 and the emitter of the insulated gate bipolar transistor T32, the cathode of the diode D34 is connected to a positive direct-current bus 31 , and the anode of the diode D33 is connected to a negative direct-current bus 32.
[0036] In the charging mode, a control device (not shown in FIG. 7) provides the same pulse-width modulation signal to gates of the insulated gate bipolar transistors T31 and T32, so that the insulated gate bipolar transistor T31 is alternately turned on and off and the insulated gate bipolar transistor T32 is alternately turned on and off.
[0037] When the insulated gate bipolar transistors T31 and T32 are turned on, the positive electrode of the rechargeable battery B, the insulated gate bipolar transistor T31 , the inductor L3, the insulated gate bipolar transistor T32, and the negative electrode of the rechargeable battery B form a current path, and the current direction thereof is indicated by the dashed single-headed arrow in FIG. 7. At this time, the current in the inductor L3 rises, and the inductor L3 stores energy. When the insulated gate bipolar transistors T31 and T32 are turned off, the negative direct-current bus 32, the diode D33, the inductor L3, the diode D34, and the positive direct-current bus 31 form another current path, and the current direction thereof is indicated by the dashed double-headed arrow in FIG. 7. At this time, the current in the inductor L3 decreases, and the inductor L3 releases and stores energy in a capacitor between the positive and negative direct-current buses. In this way, the rechargeable battery B discharges and stores electricity in the capacitor between the positive and negative direct-current buses.
[0038] Assume that an inductance value of the inductor L3 is L, a value of the current in the inductor L3 is i L, a voltage value of the inductor L3 is U L, a value of the voltage between the positive and negative direct-current buses is Udc, a voltage value of the rechargeable battery B is Uo, a period of the pulse- width modulation signal is T, a duty cycle of the pulse-width modulation signal is d, and an on time and an off time of the insulated gate bipolar transistor T31 in one pulse-width modulation signal period are respectively Ton and Toff.
[0039] Using one period of the pulse-width modulation signal as an example for description, the current in the inductor L3 is equal at an initial moment (namely, 0) of a switching period and an end moment (namely, T) of the switching period. The following equations are thus satisfied:
Figure imgf000015_0001
[0040] Thus, Udc/Uo=d/(1 -d). When the duty cycle d is less than 0.5, buck discharging of the rechargeable battery B is achieved; when the duty cycle d is greater than 0.5, boost discharging of the rechargeable battery B is achieved.
[0041] FIG. 8 is a circuit diagram of two uninterrupted power supplies, including the DC-DC converter shown in FIG. 6, that are connected in parallel. As shown in FIG. 8, a negative direct-current bus of each uninterrupted power supply is connected to a positive electrode of a rechargeable battery B through an insulated gate bipolar transistor and a diode in sequence, negative direct- current buses of the plurality of uninterrupted power supplies are isolated from each other, and each control device (not shown in FIG. 8) can independently control the voltage on a negative direct-current bus of a corresponding uninterrupted power supply, so as to charge the rechargeable battery B using electric energy in a capacitor between the positive and negative direct-current buses of the uninterrupted power supply.
[0042] FIG. 9 is a circuit diagram of two uninterrupted power supplies, including the DC-DC converter shown in FIG. 7, that are connected in parallel. As shown in FIG. 9, a negative direct-current bus of each uninterrupted power supply is connected to a positive electrode of a rechargeable battery B through a diode and an insulated gate bipolar transistor in sequence, negative direct- current buses of the plurality of uninterrupted power supplies are isolated from each other, and each control device (not shown in FIG. 9) can independently control the voltage on a negative direct-current bus of a corresponding uninterrupted power supply, so that the rechargeable battery B discharges and stores electricity in a capacitor between the positive and negative direct- current buses of the corresponding uninterrupted power supply. [0043] FIG. 10 is a circuit diagram of a DC-DC converter according to a second embodiment of the present invention. As shown in FIG. 10, the DC-DC converter 4 differs from the DC-DC converter 3 shown in FIG. 5 in that the DC- DC converter 4 further includes diodes D41 and D42 respectively connected in anti-parallel to insulated gate bipolar transistors T41 and T42; and insulated gate bipolar transistors T43 and T44 respectively connected in anti-parallel to diodes D43 and D44.
[0044] A cathode of the diode D41 and an anode of the diode D42 are respectively used for connecting to a positive electrode and a negative electrode of a direct-current power supply device (for example, a capacitor or a rechargeable battery), and a cathode of the diode D44 and an anode of the diode D43 respectively serve as a positive output terminal and a negative output terminal of the DC-DC converter 4 and are used for connecting to a positive electrode and a negative electrode of another direct-current power supply device (for example, a capacitor or a rechargeable battery). Or, a cathode of the diode D44 and an anode of the diode D43 are respectively used for connecting to a positive electrode and a negative electrode of a direct- current power supply device (for example, a capacitor or a rechargeable battery), and a cathode of the diode D41 and an anode of the diode D42 respectively serve as a positive output terminal and a negative output terminal of the DC-DC converter 4 and are used for connecting to a positive electrode and a negative electrode of another direct-current power supply device (for example, a capacitor or a rechargeable battery).
[0045] FIG. 11 is a circuit diagram of the DC-DC converter shown in FIG. 10 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery. As shown in FIG. 11 , a collector of the insulated gate bipolar transistor T41 and the cathode of the diode D41 are connected to a positive direct-current bus 41 , an emitter of the insulated gate bipolar transistor T42 and the anode of the diode D42 are connected to a negative direct-current bus 42, an emitter of the insulated gate bipolar transistor T43 and the anode of the diode D43 are connected to a negative electrode of the rechargeable battery B, and a collector of the insulated gate bipolar transistor T43 and the cathode of the diode D44 are connected to a positive electrode of the rechargeable battery B.
[0046] The operating principle of the DC-DC converter 4 is described below with reference to equivalent circuit diagrams of the DC-DC converter 4 in a charging mode and a discharging mode.
[0047] In the charging mode, a control device (not shown in FIG. 11 ) controls the insulated gate bipolar transistors T43 and T44 to turn off, and provides the same pulse-width modulation signal to gates of the insulated gate bipolar transistors T41 and T42, so that the insulated gate bipolar transistor T41 is alternately turned on and off and the insulated gate bipolar transistor T42 is alternately turned on and off. FIG. 12 is an equivalent circuit diagram of the DC-DC converter shown in FIG. 11 in a charging mode, which is the same as the circuit shown in FIG. 6. While the specific charging and discharging process is not described herein again, and buck charging or boost charging of the rechargeable battery B can also be achieved.
[0048] In the discharging mode, a control device (not shown in FIG. 11 ) controls the insulated gate bipolar transistors T41 and T42 to turn off, and provides the same pulse-width modulation signal to gates of the insulated gate bipolar transistors T43 and T44, so that the insulated gate bipolar transistor T43 is alternately turned on and off and the insulated gate bipolar transistor T44 is alternately turned on and off. FIG. 13 is an equivalent circuit diagram of the DC-DC converter shown in FIG. 11 in a discharging mode, which is the same as the circuit shown in FIG. 7. While the specific charging and discharging process is not described herein again, and boost discharging or buck discharging of the rechargeable battery B can also be achieved. [0049] With reference to FIG. 12 and FIG. 13, the DC-DC converter 4 is a bi-directional DC-DC converter and does not need to be additionally connected to a charger or a direct-current converter, thereby saving costs. Boost discharging or buck discharging of the rechargeable battery B can be achieved, and buck charging or boost charging of the rechargeable battery B can also be achieved. During charging of the rechargeable battery B, a duty cycle of a pulse-width modulation signal is changed so that a capacitor between positive and negative direct-current buses can be deeply discharged and charge the rechargeable battery B at a voltage of approximately 0 volt without producing any impact current.
[0050] FIG. 14 is a circuit diagram of two uninterrupted power supplies, including the DC-DC converter shown in FIG. 10, that are connected in parallel. Each control device (not shown in FIG. 14) can also separately control a DC- DC converter in a corresponding uninterrupted power supply so as to independently control the voltage on a negative direct-current bus of each uninterrupted power supply.
[0051] FIG. 15 is a circuit diagram of a bi-directional DC-DC converter according to a third embodiment of the present invention. As shown in FIG. 15, the bi-directional DC-DC converter 5 includes an insulated gate bipolar transistor T51 having a diode that is anti-parallel D51 , an insulated gate bipolar transistor T53 having a diode that is anti-parallel D53, and an inductor L5. A terminal 55 of the inductor L5 is connected to a node formed by connecting an anode of the diode D51 and a cathode of the diode D53, and a terminal 56 of the inductor L5 serves as a common terminal. [0052] A cathode of the diode D51 (namely, a collector of the insulated gate bipolar transistor T51 ) and the terminal 56 of the inductor L5 are respectively used for connecting to a positive electrode and a negative electrode of a direct- current power supply device (for example, a capacitor or a rechargeable battery), and the terminal 56 of the inductor L5 and an anode of the diode D53 (namely, an emitter of the insulated gate bipolar transistor T53) respectively serve as a positive output terminal and a negative output terminal of the bi directional DC-DC converter 5 and are used for connecting to a positive electrode and a negative electrode of another direct-current power supply device (for example, a capacitor or a rechargeable battery). Or, the terminal 56 of the inductor L5 and an anode of the diode D53 are respectively used for connecting to a positive electrode and a negative electrode of a direct-current power supply device (for example, a capacitor or a rechargeable battery), and a cathode of the diode D51 and the terminal 56 of the inductor L5 respectively serve as a positive output terminal and a negative output terminal of the bi directional DC-DC converter 5 and are used for connecting to a positive electrode and a negative electrode of another direct-current power supply device (for example, a capacitor or a rechargeable battery).
[0053] FIG. 16 is a circuit diagram of the bi-directional DC-DC converter shown in FIG. 15 connected between direct-current buses of an uninterrupted power supply and a rechargeable battery. The collector of the insulated gate bipolar transistor T51 and the cathode of the diode D51 are connected to a positive direct-current bus 51 , the emitter of the insulated gate bipolar transistor T53 and the anode of the diode D53 are connected to a negative electrode of the rechargeable battery B, and both a positive electrode of the rechargeable battery B and the terminal 56 of the inductor L5 are connected to a negative direct-current bus 52.
[0054] The operating principle of the bi-directional DC-DC converter 5 will be described below with reference to equivalent circuit diagrams of the bi directional DC-DC converter 5 in a charging mode and a discharging mode.
[0055] In the charging mode, a control device (not shown in FIG. 16) controls the insulated gate bipolar transistor T53 to turn off, and provides a pulse-width modulation signal to a gate of the insulated gate bipolar transistor T51 so that the insulated gate bipolar transistor T51 is alternately turned on and off. FIG. 17 is an equivalent circuit diagram of the bi-directional DC-DC converter shown in FIG. 16 in a charging mode. As shown in FIG. 17, when the insulated gate bipolar transistor T51 is turned on, the positive direct-current bus 51 , the insulated gate bipolar transistor T51 , the inductor L5, and the negative direct- current bus 52 form a current path, and the current direction thereof is indicated by the dashed single-headed arrow in FIG. 17. At this time, the inductor L5 stores energy. When the insulated gate bipolar transistor T51 is turned off, the inductor L5, the rechargeable battery B, and the diode D53 form a current path, and the current direction thereof is indicated by the dashed double-headed arrow in FIG. 17. At this time, the inductor L5 releases energy and charges the rechargeable battery B.
[0056] Assume that an inductance value of the inductor L5 is L, a value of the current in the inductor L5 is i L, a voltage value of the inductor L5 is U L, a value of the voltage between the positive and negative direct-current buses is Udc, a voltage value of the rechargeable battery B is Uo, a period of the pulse- width modulation signal is T, a duty cycle of the pulse-width modulation signal is d, and an on time and an off time of the insulated gate bipolar transistor T51 in one pulse-width modulation signal period are respectively Ton and Toff.
[0057] Using one period of the pulse-width modulation signal as an example for description, the current in the inductor L5 is equal at an initial moment (namely, 0) of a switching period and an end moment (namely, T) of the switching period. The following equations are thus satisfied:
Figure imgf000021_0001
[0058] Thus, Uo/Udc=d/(1 -d). When the duty cycle d is less than 0.5, buck charging of the rechargeable battery B is achieved. When the duty cycle d is greater than 0.5, boost charging of the rechargeable battery B is achieved.
[0059] In the discharging mode, a control device (not shown in FIG. 16) controls the insulated gate bipolar transistor T51 to turn off, and provides a pulse-width modulation signal to a gate of the insulated gate bipolar transistor T53 so that the insulated gate bipolar transistor T53 is alternately turned on and off. FIG. 18 is an equivalent circuit diagram of the bi-directional DC-DC converter shown in FIG. 16 in a discharging mode. As shown in FIG. 18, when the insulated gate bipolar transistor T53 is turned on, the rechargeable battery B, the inductor L5, and the insulated gate bipolar transistor T53 form a current path, and the current direction thereof is indicated by the dashed single- headed arrow in FIG. 18. At this time, the inductor L5 stores energy. When the insulated gate bipolar transistor T53 is turned off, the negative direct-current bus 52, the inductor L5, the diode D51 , and the positive direct-current bus 51 form another current path, and the current direction thereof is indicated by the dashed double-headed arrow in FIG. 18. At this time, the inductor L5 releases and stores energy in a capacitor between the positive direct-current bus 51 and the negative direct-current bus 52.
[0060] Assume that an inductance value of the inductor L5 is L, a value of the current in the inductor L5 is i L, a voltage value of the inductor L5 is U L, a value of the voltage between the positive and negative direct-current buses is Udc, a voltage value of the rechargeable battery B is Uo, a period of the pulse- width modulation signal is T, a duty cycle of the pulse-width modulation signal is d, and an on time and an off time of the insulated gate bipolar transistor T53 in one pulse-width modulation signal period are respectively Ton and Toff.
[0061] Using one period of the pulse-width modulation signal as an example for description, the current in the inductor L5 is equal at an initial moment (namely, 0) of a switching period and an end moment (namely, T) of the switching period. The following equations are thus satisfied:
Figure imgf000023_0001
[0062] Thus, Udc/Uo=d/(1 -d). When the duty cycle d is less than 0.5, buck discharging of the rechargeable battery B is achieved; when the duty cycle d is greater than 0.5, boost discharging of the rechargeable battery B is achieved.
[0063] With reference to FIG. 17 and FIG. 18, the bi-directional DC-DC converter 5 can controllably transmit electric energy in the capacitor between the positive and negative direct-current buses to the rechargeable battery B, and can also transmit electric energy in the rechargeable battery B to the capacitor between the positive and negative direct-current buses, thereby achieving bi-directional energy transmission.
[0064] FIG. 19 is a circuit diagram of a bi-directional DC-DC converter according to a fourth embodiment of the present invention. As shown in FIG. 19, the bi-directional DC-DC converter 6 differs from the bi-directional DC-DC converter 5 shown in FIG. 15 in that the bi-directional DC-DC converter 6 further includes an insulated gate bipolar transistor T62 having a diode that is anti-parallel D62 and an insulated gate bipolar transistor T64 having a diode that is anti-parallel D64, where a cathode of the diode D62 and an anode of the diode D64 are connected to a terminal 66 of an inductor L6.
[0065] With reference to the DC-DC converter 4 in FIG. 10, the bi-directional DC-DC converter 6 in this embodiment has the same topology structure as that of the DC-DC converter 4 in FIG. 10, and the operating principle thereof will not be described herein again. Thus, the bi-directional DC-DC converter 6 can also be used in a plurality of uninterrupted power supplies connected in parallel.
[0066] In other embodiments of the present invention, a switching tube such as a metal-oxide-semiconductor field effect transistor (MOSFET) is used in place of the insulated gate bipolar transistor in the aforementioned embodiment.
[0067] The present invention further provides an uninterrupted power supply, which includes the DC-DC converter or bi-directional DC-DC converter in the aforementioned embodiment of the present invention, a power factor correction circuit (PFC) and an inverter, where the DC-DC converter or the bi- directional DC-DC converter is connected between positive and negative direct-current buses and a rechargeable battery, an input terminal of the PFC is connected to an alternating-current power supply (for example, a mains supply), an output terminal of the PFC is connected to the positive and negative direct-current buses, an input terminal of the inverter is connected to the positive and negative direct-current buses, and an output terminal of the inverter is used for providing an alternating current to a load.
[0068] Although the present invention has been described through preferred embodiments, the present invention is not limited to the embodiments described herein, but includes various changes and variations made without departing from the scope of the present invention.

Claims

1 . A DC-DC converter, comprising:
a first switching tube, an inductor, and a second switching tube connected in sequence; and
a first diode and a second diode, wherein a cathode of the first diode and an anode of the second diode are respectively connected to two terminals of the inductor.
2. The DC-DC converter according to claim 1 , wherein when both the first switching tube and the second switching tube are turned on, the first switching tube, the inductor and the second switching tube form a first current path; when both the first switching tube and the second switching tube are turned off, the first diode, the inductor, and the second diode form a second current path.
3. The DC-DC converter according to claim 2, wherein
the first switching tube is a first insulated gate bipolar transistor, and an emitter of the first insulated gate bipolar transistor is connected to the cathode of the first diode; and
the second switching tube is a second insulated gate bipolar transistor, and a collector of the second insulated gate bipolar transistor is connected to the anode of the second diode, wherein
a collector of the first insulated gate bipolar transistor and an emitter of the second insulated gate bipolar transistor are respectively used for connecting to a positive electrode and a negative electrode of a first direct- current power supply device; and a cathode of the second diode and an anode of the first diode are respectively used for connecting to a positive electrode and a negative electrode of a second direct-current power supply device.
4. The DC-DC converter according to any one of claims 1 to 3, wherein the DC-DC converter further comprises:
a diode connected in anti-parallel to the first switching tube; a diode connected in anti-parallel to the second switching tube;
a third switching tube connected in anti-parallel to the first diode; and a fourth switching tube connected in anti-parallel to the second diode.
5. The DC-DC converter according to any one of claims 1 to 3, further comprising a control device for providing the same pulse-width modulation signal to the first switching tube and the second switching tube, so that the first switching tube is alternately turned on and off and the second switching tube is alternately turned on and off.
6. The DC-DC converter according to claim 4, further comprising a control device for
controlling both the third switching tube and the fourth switching tube to turn off, and providing the same pulse-width modulation signal to the first switching tube and the second switching tube, so that the first switching tube is alternately turned on and off and the second switching tube is alternately turned on and off; or
controlling both the first switching tube and the second switching tube to turn off, and providing the same pulse-width modulation signal to the third switching tube and the fourth switching tube, so that the third switching tube is alternately turned on and off and the fourth switching tube is alternately turned on and off.
7. A bi-directional DC-DC converter, comprising:
a first switching tube having a first diode that is anti-parallel;
a second switching tube having a second diode that is anti-parallel; and an inductor, wherein one terminal of the inductor is connected to an anode of the first diode and a cathode of the second diode, and the other terminal of the inductor serves as a common terminal.
8. The bi-directional DC-DC converter according to claim 7, wherein the first switching tube is a first insulated gate bipolar transistor, the second switching tube is a second insulated gate bipolar transistor, and one terminal of the inductor is connected to an emitter of the first insulated gate bipolar transistor and a collector of the second insulated gate bipolar transistor, wherein
a collector of the first insulated gate bipolar transistor and the other terminal of the inductor are respectively used for connecting to a positive electrode and a negative electrode of a first direct-current power supply device, and an emitter of the second insulated gate bipolar transistor and the other terminal of the inductor are respectively used for connecting to a negative electrode and a positive electrode of a second direct-current power supply device.
9. The bi-directional DC-DC converter according to claim 7, wherein the bi-directional DC-DC converter further comprises:
a third switching tube having a third diode that is anti-parallel; and a fourth switching tube having a fourth diode that is anti-parallel, wherein
a cathode of the third diode and an anode of the fourth diode are connected to the other terminal of the inductor.
10. The bi-directional DC-DC converter according to claim 9, wherein a cathode of the first diode and an anode of the third diode are respectively used for connecting to a positive electrode and a negative electrode of a first direct- current power supply device, and an anode of the second diode and a cathode of the fourth diode are respectively used for connecting to a negative electrode and a positive electrode of a second direct-current power supply device.
11. The bi-directional DC-DC converter according to any one of claims 7 to 8, further comprising a control device for controlling the second switching tube to turn off, and providing a pulse- width modulation signal to the first switching tube so that the first switching tube is alternately turned on and off; or
controlling the first switching tube to turn off, and providing a pulse-width modulation signal to the second switching tube so that the second switching tube is alternately turned on and off.
12. The bi-directional DC-DC converter according to any one of claims 9 to 10, further comprising a control device for
controlling the second switching tube and the fourth switching tube to turn off, and providing the same pulse-width modulation signal to the first switching tube and the third switching tube, so that the first switching tube is alternately turned on and off and the third switching tube is alternately turned on and off; or
controlling the first switching tube and the third switching tube to turn off, and providing the same pulse-width modulation signal to the second switching tube and the fourth switching tube, so that the second switching tube is alternately turned on and off and the fourth switching tube is alternately turned on and off.
13. An uninterrupted power supply, comprising:
the DC-DC converter according to any one of claims 1 to 6 or the bi directional DC-DC converter according to any one of claims 7 to 12, wherein the DC-DC converter or the bi-directional DC-DC converter is connected between positive and negative direct-current buses and a rechargeable battery;
a power factor correction circuit, wherein an input terminal of the power factor correction circuit is used for connecting to an alternating-current power supply, and an output terminal of the power factor correction circuit is connected to the positive and negative direct-current buses; and an inverter, wherein an input terminal of the inverter is connected to the positive and negative direct-current buses, and an output terminal of the inverter is used for providing an alternating current.
PCT/EP2019/025409 2018-11-21 2019-11-21 Dc-dc converter, bi-directional dc-dc converter, and uninterrupted power supply comprising same Ceased WO2020104064A1 (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11362525B2 (en) * 2017-12-29 2022-06-14 Lianghuan FENG Full direct-current boost/buck power transmission system and method
CN114649856A (en) * 2022-04-18 2022-06-21 广州爱申特科技股份有限公司 High-efficiency charging circuit
WO2025065146A1 (en) * 2023-09-25 2025-04-03 深圳欣锐科技股份有限公司 Direct-current charging module and direct-current charging pile

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN118367780A (en) * 2024-04-26 2024-07-19 山东艾诺智能仪器有限公司 A circuit and modulation method for reducing filter inductance of bidirectional DC power supply

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2277257A1 (en) * 2008-04-02 2011-01-26 American Power Conversion Corporation Non-isolated charger with bi-polar inputs
US20120195077A1 (en) * 2009-07-10 2012-08-02 Thales Novel architecture of a compensator for power factors and harmonics for a power distribution system
US20140009106A1 (en) * 2012-07-09 2014-01-09 Davide Andrea Limiting excessive currents during connection of a battery or cell in parallel with other batteries, cells or capacitive loads
WO2017125193A1 (en) * 2015-12-04 2017-07-27 Technische Universiteit Eindhoven Flexbattery
DE102017006819A1 (en) * 2016-09-22 2018-03-22 Sew-Eurodrive Gmbh & Co Kg System and method for operating a system

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106602853A (en) * 2015-10-15 2017-04-26 伊顿公司 Discharge device and discharge method for DC buses of uninterruptible power supply

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2277257A1 (en) * 2008-04-02 2011-01-26 American Power Conversion Corporation Non-isolated charger with bi-polar inputs
US20120195077A1 (en) * 2009-07-10 2012-08-02 Thales Novel architecture of a compensator for power factors and harmonics for a power distribution system
US20140009106A1 (en) * 2012-07-09 2014-01-09 Davide Andrea Limiting excessive currents during connection of a battery or cell in parallel with other batteries, cells or capacitive loads
WO2017125193A1 (en) * 2015-12-04 2017-07-27 Technische Universiteit Eindhoven Flexbattery
DE102017006819A1 (en) * 2016-09-22 2018-03-22 Sew-Eurodrive Gmbh & Co Kg System and method for operating a system

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
KELVIN MANAVAR ET AL: "Non-Isolated Bi-directional DC-DC Converters for Plug-In Hybrid Electric Vehicle Charge Station Application Non-Isolated Bi-directional DC-DC Converters for Plug-In Hybrid Electric Vehicle Charge Station Application", 1 April 2015 (2015-04-01), XP055666509, Retrieved from the Internet <URL:https://www.researchgate.net/profile/Nitin_Adroja/publication/301629100_Non-Isolated_Bi-directional_DC-DC_Converters_for_Plug-In_Hybrid_Electric_Vehicle_Charge_Station_Application/links/571ed18a08aed056fa2274d8.pdf> [retrieved on 20200207] *
LEMMEN E ET AL: "Robust control of extended commutation cell based converters", 2016 18TH EUROPEAN CONFERENCE ON POWER ELECTRONICS AND APPLICATIONS (EPE'16 ECCE EUROPE), JOINTLY OWNED BY IEEE-PELS AND EPE ASSOCIATION, 5 September 2016 (2016-09-05), pages 1 - 10, XP032985034, DOI: 10.1109/EPE.2016.7695317 *
M EJAS AHAMED ET AL: "Volume 5 Issue 4 Review of Bidirectional DC-DC Converters", INTERNATIONAL JOURNAL OF ADVANCE RESEARCH AND INNOVATION, 15 December 2017 (2017-12-15), pages 433 - 437, XP055666527, Retrieved from the Internet <URL:https://ijari.org/assets/papers/5/4/IJARI-EE-17-12-109.pdf> [retrieved on 20200207] *
SALMAN HABIB ET AL: "Assessment of electric vehicles concerning impacts, charging infrastructure with unidirectional and bidirectional chargers, and power flow comparisons", INTERNATIONAL JOURNAL OF ENERGY RESEARCH, vol. 42, no. 11, 18 April 2018 (2018-04-18), GB, pages 3416 - 3441, XP055666529, ISSN: 0363-907X, DOI: 10.1002/er.4033 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11362525B2 (en) * 2017-12-29 2022-06-14 Lianghuan FENG Full direct-current boost/buck power transmission system and method
CN114649856A (en) * 2022-04-18 2022-06-21 广州爱申特科技股份有限公司 High-efficiency charging circuit
WO2025065146A1 (en) * 2023-09-25 2025-04-03 深圳欣锐科技股份有限公司 Direct-current charging module and direct-current charging pile

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