WO2023216705A1 - 一种功率变换电路以及供电*** - Google Patents

一种功率变换电路以及供电*** Download PDF

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Publication number
WO2023216705A1
WO2023216705A1 PCT/CN2023/080881 CN2023080881W WO2023216705A1 WO 2023216705 A1 WO2023216705 A1 WO 2023216705A1 CN 2023080881 W CN2023080881 W CN 2023080881W WO 2023216705 A1 WO2023216705 A1 WO 2023216705A1
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Prior art keywords
voltage
rectifier
output
target
period
Prior art date
Application number
PCT/CN2023/080881
Other languages
English (en)
French (fr)
Inventor
黄朱勇
王亮
李楚杉
祝琳
李武华
Original Assignee
华为数字能源技术有限公司
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Publication of WO2023216705A1 publication Critical patent/WO2023216705A1/zh

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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
    • H02M1/00—Details of apparatus for conversion
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • H02M1/325—Means for protecting converters other than automatic disconnection with means for allowing continuous operation despite a fault, i.e. fault tolerant converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—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
    • 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
    • H02M1/0067—Converter structures employing plural converter units, other than for parallel operation of the units on 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
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0067—Converter structures employing plural converter units, other than for parallel operation of the units on a single load
    • H02M1/007—Plural converter units in cascade
    • 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
    • H02M1/0095—Hybrid converter topologies, e.g. NPC mixed with flying capacitor, thyristor converter mixed with MMC or charge pump mixed with buck
    • 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
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • 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
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static 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
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
    • H02M7/06—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes without control electrode or semiconductor devices without control electrode
    • 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
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
    • H02M7/06—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes without control electrode or semiconductor devices without control electrode
    • H02M7/066—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes without control electrode or semiconductor devices without control electrode particular circuits having a special characteristic
    • 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
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
    • H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/21—Conversion of ac power input into dc power output without possibility of reversal 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
    • H02M7/217—Conversion of ac power input into dc power output without possibility of reversal 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

Definitions

  • the present application relates to the field of power electronics technology, and in particular to a power conversion circuit and power supply system.
  • Solid State Transformer Solid State Transformer
  • SST Solid State Transformer
  • the medium-voltage AC voltage is converted into a medium-voltage DC voltage through a solid-state transformer (also known as a rectifier or power conversion circuit), and the low-voltage DC voltage is obtained after conversion by a high-frequency isolated DC-to-DC circuit.
  • the low-voltage inverter converts the low-voltage DC voltage into Sent to low voltage AC voltage distribution network.
  • This method can isolate the medium-voltage power grid and the data center distribution network, achieve high power quality, directly provide low-voltage energy storage battery interfaces, and can eliminate the need for low-power density power frequency transformers. Therefore, this solution will become the first choice for medium-voltage UPS power supply systems in the future.
  • the above-mentioned medium-voltage UPS power supply system usually adopts a cascade topology, and the power conversion circuit of this cascade topology adopts a cascade H-bridge structure.
  • the above-mentioned medium-voltage UPS power supply system has large uncertainties (failures), so the stability is poor.
  • the existing technical solutions for fault maintenance of the above-mentioned structure mainly include the following methods: additional power module method, special modulation method and common-mode voltage signal injection methods.
  • Additional power module method This method can be divided into cold standby and hot standby. It mainly relies on additional modules to ensure that the cascaded H-bridge structure can operate normally after a failure. However, this method requires additional hardware equipment, so the cost is usually higher.
  • This application provides a power conversion circuit and a power supply system. After the power conversion circuit in a medium-voltage UPS power supply system fails, fault processing is performed on the power conversion circuit, thereby ensuring that the power conversion circuit and the medium-voltage UPS power supply system can continue to operate stably. run.
  • this application provides a power conversion circuit.
  • the power conversion circuit includes N rectifiers and a control unit, where N is a positive integer greater than or equal to 2;
  • Each rectifier includes two rectifier modules, and each rectifier module includes multiple diodes and multiple switch tubes; the input terminals of each of the N rectifiers are connected in series, and the output terminals of each of the N rectifiers are connected in series. Parallel connection; rectifier, used for: receiving AC power provided by the AC power supply, converting the AC power provided by the AC power supply into DC voltage for output; control unit, used for: disconnecting the target rectifier when determining that the diode in the target rectifier module is short-circuited
  • the switch tube in the module adjusts the output voltage of the target rectifier where the target rectifier module is located to the first voltage, and adjusts the sum of the output voltages of other rectifiers among the N rectifiers except the target rectifier to the second voltage, the first voltage It is less than the output voltage of the target rectifier when it is working normally; the second voltage is greater than the sum of the output voltages of other rectifiers when it is working normally.
  • the type of rectifier may be a Vienna rectifier, and the rectifier
  • the entire power conversion circuit can continue to operate stably by reconfiguring other switching tubes. Compared with the existing technology that uses external backup solutions, It can reduce the cost and volume of the power conversion circuit.
  • control unit is specifically configured to: adjust the output voltage of each other rectifier to a third voltage, and the third voltage is greater than the output voltage of the target rectifier when the target rectifier is working normally.
  • each rectifier specifically includes: a first rectifier module, a second rectifier module, a first output capacitor unit, and a second output capacitor unit;
  • the first rectifier module includes: a first diode, a second diode, a first switch tube, a second switch tube;
  • a second rectifier module including: a third diode, a fourth diode, a third switch tube, a fourth switch tube; a first output capacitor unit
  • the second end of the rectifier is connected to the first end of the second output capacitor unit; the input positive end of the rectifier is connected to the positive end of the first diode, the input positive end of the rectifier is connected to the negative end of the second diode, and the rectifier
  • the input positive terminal is also connected to the first terminal of the first switch tube, the third terminal of the first switch tube is connected to the third terminal of the second switch tube, and the negative terminal of the first diode is connected to the third terminal of the first output capacitor unit.
  • One end is connected, the positive end of the second diode is connected to the second end of the second output capacitor unit; the input negative end of the rectifier is connected to the positive end of the third diode, and the input negative end of the rectifier is connected to the fourth diode.
  • the negative end of the tube is connected, the input negative end of the rectifier is also connected to the first end of the third switch tube, the third end of the third switch tube is connected to the third end of the fourth switch tube, and the negative end of the third diode
  • the positive end of the fourth diode is connected to the first end of the first output capacitor unit, and the positive end of the fourth diode is connected to the second end of the second output capacitor unit; the first end of the second switch tube and the first end of the fourth switch tube are connected to The second terminal of the first output capacitor unit is connected.
  • the control unit is specifically configured to: when the first diode determined in the target rectifier is short-circuited, disconnect the first switching tube and the second switching tube, and close the third switching tube within the first period of time.
  • the switching tube and the fourth switching tube adjust the output voltage of the target rectifier to the fourth voltage, and the sum of the output voltages of other rectifiers except the target rectifier is adjusted to the fifth voltage; during the second period, the third switch is turned off tube and the fourth switch tube, control the target rectifier not to output voltage, and the sum of the output voltages of other rectifiers except the target rectifier is adjusted to the total voltage output by the power conversion circuit when it is working normally;
  • the first period is when the current flows from the target rectifier The period when the input positive terminal flows to the input negative terminal
  • the second period is the period when the current flows from the input negative terminal of the target rectifier to the input positive terminal
  • the fourth voltage is less than the output voltage of the target rectifier when it is working normally
  • the sum of the fourth voltage and the fifth voltage is equal to
  • the control unit is specifically configured to: when the second diode determined in the target rectifier is short-circuited, disconnect the first switching tube and the second switching tube, and within the first period, disconnect the third switching tube.
  • the third switch tube and the fourth switch tube control the target rectifier not to output voltage, and the sum of the output voltages of other rectifiers except the target rectifier is adjusted to the total voltage output when the power conversion circuit is operating normally; during the second period, the third switch is closed
  • the three switching tubes and the fourth switching tube adjust the output voltage of the target rectifier to the sixth voltage, and the sum of the output voltages of other rectifiers except the target rectifier is adjusted to the seventh voltage; wherein, the first period is when the current flows from the target rectifier The period when the input positive terminal flows to the input negative terminal, the second period is the period when the current flows from the input negative terminal of the target rectifier to the input positive terminal, the sixth voltage is greater than the output voltage of the target rectifier when it is working normally; the sum of the sixth voltage and the seventh voltage is equal to The
  • control unit is specifically configured to: when the third diode determined in the target rectifier is short-circuited, disconnect the third switching tube and the fourth switching tube, and within the first period, disconnect the third switching tube.
  • the first switch tube and the second switch tube control the target rectifier not to output voltage, and the sum of the output voltages of other rectifiers except the target rectifier is adjusted to the total voltage output when the power conversion circuit is operating normally; during the second period, the first switch tube is closed.
  • a switching tube and a second switching tube adjust the output voltage of the target rectifier to the eighth voltage, and the sum of the output voltages of other rectifiers except the target rectifier is adjusted to the ninth voltage; wherein, the first period is when the current flows from the target rectifier The period during which the input positive terminal flows to the input negative terminal.
  • the second period is the period during which the current flows from the input negative terminal of the target rectifier to the input positive terminal.
  • the eighth voltage is greater than the output voltage of the target rectifier during normal operation; the sum of the eighth voltage and the ninth voltage is equal to The total voltage output by the power conversion circuit when it is working normally.
  • control unit is specifically configured to: when the fourth diode determined in the target rectifier is short-circuited, disconnect the third switching tube and the fourth switching tube, and close the first switching tube within the first period of time.
  • the switching tube and the second switching tube adjust the output voltage of the target rectifier to the tenth voltage, and the sum of the output voltages of other rectifiers except the target rectifier is adjusted to the eleventh voltage; during the second period, the first voltage is turned off.
  • the switching tube and the second switching tube control the target rectifier not to output voltage, and the sum of the output voltages of other rectifiers except the target rectifier is adjusted to the total voltage output by the power conversion circuit when it is working normally; wherein the first period is when the current flows from the target rectifier to the target rectifier.
  • the second period is the period when the current flows from the input negative terminal of the target rectifier to the input positive terminal.
  • the tenth voltage is greater than the output voltage of the target rectifier during normal operation; the tenth voltage and the eleventh voltage are The sum is equal to the total voltage output by the power conversion circuit during normal operation.
  • the rectifier described in the above aspects of this application takes the application scenario of single-phase electricity as an example.
  • the power conversion circuit is used for power conversion of three-phase electricity
  • a fault occurs in the power conversion circuit of one phase of electricity.
  • the fault occurs, only the output voltage of the power conversion circuit where the faulty diode is located needs to be adjusted.
  • the output voltage of the power conversion circuit corresponding to the non-faulty diode and the modulation wave reference voltage do not need to be adjusted, thus maintaining the stable operation of the cascaded power conversion circuit. sex.
  • control unit is also used to: reduce the load impedance connected to the target rectifier.
  • reduce the load impedance connected to the back end of the target rectifier the voltage stability of the first output capacitor unit and the second output capacitor unit in the target rectifier is ensured.
  • the negative input terminal of the previous rectifier is connected to the positive input terminal of the next rectifier, and the positive input terminal of the first rectifier is connected to the positive power supply terminal of the AC power supply. terminals are connected, the input negative terminal of the last rectifier is connected to the negative power supply terminal of the AC power supply; the output positive terminals of each rectifier are connected to each other, and the output negative terminals of each rectifier are connected to each other.
  • the present application provides a power supply system.
  • the power supply system includes N DC-to-DC converters and power conversion circuits as in the first aspect, N DC-DC converters and N power conversion circuits.
  • the rectifiers are connected in a one-to-one correspondence; each DC-DC converter among the N DC-DC converters is used to: output the corresponding connected rectifier The first DC voltage output is converted into a second DC voltage; the first DC voltage is greater than the second DC voltage.
  • FIG. 1 is a structural diagram of a UPS power supply system based on solid-state transformer
  • Figure 2 is a schematic structural diagram of a power conversion circuit
  • Figure 3 is a schematic diagram of the specific structure of a rectifier
  • Figure 4A is a schematic diagram of the current flow path in the first period when the first diode is short-circuited
  • Figure 4B is a schematic diagram of the current flow path in the second period when the first diode is short-circuited
  • Figure 4C is the voltage timing diagram 1 of the target rectifier
  • Figure 5A is a schematic diagram of the current flow path in the first period when the second diode is short-circuited
  • Figure 5B is a schematic diagram of the current flow path in the second period when the second diode is short-circuited
  • Figure 5C is the voltage timing diagram 2 of the target rectifier
  • Figure 6A is a schematic diagram of the current flow path in the first period when the third diode is short-circuited
  • Figure 6B is a schematic diagram of the current flow path in the second period when the third diode is short-circuited
  • Figure 6C is the voltage timing diagram 3 of the target rectifier
  • Figure 7A is a schematic diagram of the current flow path in the first period when the fourth diode is short-circuited
  • Figure 7B is a schematic diagram of the current flow path in the second period when the fourth diode is short-circuited
  • Figure 7C is the voltage timing diagram 4 of the target rectifier
  • Figure 8 is a schematic diagram of the cascade topology of the rectifier
  • Figure 9 is a schematic structural diagram of a power supply system.
  • connection in the embodiments of this application refers to electrical connection, and the connection between two electrical components may be a direct or indirect connection between two electrical components.
  • a and B can be connected directly, or A and B can be connected indirectly through one or more other electrical components.
  • a and B can be connected, or A and C can be connected directly.
  • C and B are directly connected, and A and B are connected through C.
  • the power conversion circuit converts medium-voltage AC power input into low-voltage DC output, which will be more suitable for many types of markets and can adapt to the increasing power capacity and power in these markets.
  • Solid-state transformer is a new isolated AC-DC-AC device based on power electronic converter.
  • Figure 1 is a structural diagram of a UPS power supply system based on solid-state transformers. The structure in Figure 1 first converts medium-voltage alternating current into medium-voltage direct current through an alternating current-to-direct current converter (AC/DC) circuit, and then converts the high-frequency isolated DC to direct current (direct current-to-direct current). converter (DC/DC) circuit to convert low-voltage direct current, which is then connected to a low-voltage inverter to transmit the direct current to the low-voltage AC distribution network.
  • AC/DC alternating current-to-direct current converter
  • DC/DC converter
  • This kind of structure can isolate the medium-voltage power grid and the distribution network of the data center, and the power quality is high.
  • the power conversion circuit provided by this application allows the entire power conversion circuit to continue to operate stably by reconfiguring other switching tubes after a short-circuit failure occurs in the diode of the internal rectifier. Compared with the existing technology that uses external backup solutions, it can Reduce the cost and size of power circuits.
  • Figure 2 is a schematic structural diagram of a power conversion circuit; the power conversion circuit 200 provided by the embodiment of the present application may include: N rectifiers 201 and control units 202, where N is a positive integer greater than or equal to 2;
  • Each rectifier 201 includes two rectifier modules 2010, and each rectifier module 2010 includes a plurality of diodes and a plurality of switch tubes; the input terminals of each of the N rectifiers 201 are connected in series, and the input terminals of each of the N rectifiers 201 are connected in series. The output terminals of each rectifier 201 are connected in parallel;
  • the rectifier 201 is used to: receive the AC power provided by the AC power supply 203, and convert the AC power provided by the AC power supply 203 into a DC voltage for output.
  • the control unit 202 is configured to: when it is determined that the diode in the target rectifier module 2110 is short-circuited, disconnect the switch tube in the target rectifier module 2110, adjust the output voltage of the target rectifier 211 where the target rectifier module 2110 is located to the first voltage, and set N The sum of the output voltages of other rectifiers in each rectifier 201 except the target rectifier 211 is adjusted to a second voltage.
  • the first voltage is smaller than the output voltage of the target rectifier 211 when it is working normally; the second voltage is larger than the sum of the output voltages of other rectifiers 201 when it is working normally. and.
  • the voltage to be compared is an AC voltage
  • the voltage parameter to be compared can be the effective value of the voltage or the peak-to-peak value of the voltage, etc., which are not too limited here.
  • the structure of the rectifier 201 in this application is evolved from a diode rectifier.
  • the rectifier 201 can be a Vienna rectifier structure, which includes two identical single-phase rectifier modules, and each rectifier module includes two A diode and two switch tubes. The two switch tubes facing each other can be equivalent to a two-way switch, thereby realizing electrical The current flows in both directions.
  • the modulation method of the rectifier 201 is similar to that of the diode clamped multi-level converter. At a specific time, the rectifier 201 clamps the modulation wave to five levels respectively, thereby reducing the distortion of the current and reducing the number of switching actions. .
  • rectifier 201 in this application can be, but is not limited to, the specific structure described in the above embodiments. Rectifiers with other structures can also be applied in the embodiments of this application, and are not specifically limited here.
  • the control unit 202 can be connected to the rectifier 201 to control the switching tubes in the rectifier 201 .
  • Each rectifier 201 among the N rectifiers 201 adopts a front-series and rear-parallel structure. Specifically, the input end of each rectifier 201 among the N rectifiers 201 is connected in series, and the output end of each rectifier 201 among the N rectifiers 201 By connecting in parallel, the AC power provided by the AC power supply 203 is converted into a DC voltage for output.
  • the negative input terminal of the previous rectifier is connected to the positive input terminal of the next rectifier, and the positive input terminal of the first rectifier is connected to the power supply of the AC power supply.
  • the positive terminals are connected, and the input negative terminal of the last rectifier is connected to the negative power supply terminal of the AC power supply; the output positive terminals of each rectifier are connected to each other, and the output negative terminals of each rectifier are connected to each other.
  • the switching tube in the rectifier 201 in the embodiment of the present application can be a metal oxide semiconductor field effect transistor (MOSFET), a bipolar junction transistor (BJT), an insulated gate double tube
  • MOSFET metal oxide semiconductor field effect transistor
  • BJT bipolar junction transistor
  • IGBT insulated gate bipolar transistor
  • FET field effect transistor
  • SiC silicon carbide
  • GaN gallium nitride
  • Each switch tube may include a first electrode, a second electrode and a control electrode, where the control electrode is used to control on or off of the switch. When the switch is turned on, current can be transmitted between the first electrode and the second electrode of the switch.
  • the control electrode of the switch is the gate
  • the first electrode of the switch can be the source of the switch
  • the second electrode can be the drain of the switch
  • the first electrode can be the drain of the switch
  • the second electrode can be the drain of the switch.
  • the two electrodes can be the source of the switch.
  • the first end of the main power tube and the first end of the auxiliary power tube can both be a source electrode or a drain electrode.
  • the first end is the source electrode
  • the second end can be a source electrode.
  • terminal is the drain, and when the first terminal is the drain, the second terminal is the source.
  • the control unit 202 in the embodiment of this application can be a general central processing unit (CPU), a general processor, a digital signal processing (DSP), an application specific integrated circuit (ASIC), Field programmable gate array (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. It may implement or execute the various illustrative logical blocks, modules, and circuits described in connection with this disclosure.
  • the control unit 202 can also be a combination that implements computing functions, such as one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.
  • the control unit 202 can also include multiple control sub-units, each control sub-unit is Regarding controlling the corresponding rectifier 201, there is no specific limitation here.
  • the control unit 202 determines a specific control strategy by monitoring in real time whether the diodes of the rectifier modules in each rectifier 201 have short-circuit faults to ensure that the entire power conversion circuit 200 can continue to operate normally and smoothly. Among them, when it is determined that the diode in the target rectifier module 2110 is short-circuited, first disconnect the switch tube in the rectifier module corresponding to the diode where the fault is located, that is, disconnect the switch tube in the target rectifier module 2110, and adjust the switch tube on the other side. The switching state of the switch tube is used to maintain the normal and smooth operation of the power conversion circuit 200.
  • the specific control strategy is related to the current direction of the alternating current and the fault location of the diode.
  • the diode in the target rectifier module 2110 fails, it is difficult for the target rectifier 211 where the target rectifier module 2110 is located to output a rectifier. Output voltage during normal operation. By adjusting the switching state of the switching tube in the rectifier module on the other side of the target rectifier module 2110, the output voltage of the target rectifier 211 is reduced to the first voltage.
  • the first voltage is smaller than the output voltage of the target rectifier 211 during normal operation. In different current directions, the positions of the short-circuited diodes are different, so the magnitude of the first voltage is also different.
  • the first voltage may be 0, or the first voltage may be half of the output voltage of the rectifier when it is operating normally, etc. It should be noted that the first voltage is only limited to the output voltage when the rectifier is operating normally, and the specific magnitude is not limited.
  • the sum of the voltages output by other rectifiers can be increased to compensate for the target rectifier.
  • the small output part of 211 can maintain the normal and smooth operation of the power conversion circuit 200. Specifically, the sum of the output voltages of other rectifiers among the N rectifiers 201 except the target rectifier 211 is adjusted to the second voltage.
  • the second voltage is greater than the sum of the output voltages of other rectifiers 201 during normal operation. Under different current directions, the magnitude of the second voltage is also different due to the different connection positions of the short-circuited diodes.
  • the second voltage may be equal to the output voltage of the entire power conversion circuit 200 when the entire power conversion circuit 200 is operating normally, etc. It should be noted that the second voltage is only limited to be greater than the sum of the voltages output by other rectifiers 201 during normal operation, and the specific magnitude is not limited.
  • the number of switching devices in the above-mentioned rectifier 201 may be related to the AC voltage of the AC power supply 203 and the voltage withstand capability of the switching devices.
  • the number of switching devices in the rectifier 201 when the input AC voltage is large, When the switching device has a low withstand voltage capability, multiple switch tubes can be connected in series to divide the AC voltage of the AC power supply 203, thereby ensuring that the switch tubes with low withstand voltage capability can also work normally.
  • the embodiment of the present application only limits the sum of the output voltages of other rectifiers except the target rectifier 211, and does not limit the size of the output voltage of each of the other rectifiers respectively.
  • the output voltage of each rectifier can be the same or different.
  • the output voltage of each rectifier in other rectifiers is also related to the parameters of the internal components of the rectifier, and is not limited here.
  • control unit 202 may adjust the output voltage of each of the other rectifiers to a third voltage, where the third voltage is greater than when the target rectifier is operating normally.
  • the sum of the output voltages of other rectifiers is N-1 times the third voltage, and the N-1 times the third voltage can be the second voltage.
  • Figure 3 is a schematic diagram of the specific structure of the rectifier of the present application; the specific structure of each rectifier can be: a first rectification module 301, a second rectification module 302, a first output capacitor unit 303 and a second output capacitor.
  • the first rectifier module 301 includes: a first diode 3011, a second diode 3012, a first switch tube 3013, and a second switch tube 3014;
  • the second rectifier module 302 includes: a Three diodes 3021, a fourth diode 3022, a third switching tube 3023, a fourth switching tube 3024; the second end of the first output capacitor unit 303 and the first end of the second output capacitor unit 304 Connection; the input positive terminal 305 of the rectifier is connected to the positive terminal of the first diode 3011, the input positive terminal 305 of the rectifier is connected to the negative terminal of the second diode 3012, and the input positive terminal 305 of the rectifier is also connected to The first terminal of the first switch tube 3013 is connected to the third terminal of the second switch tube 3014.
  • the negative terminal of the first diode 3011 is connected to the third terminal of the second switch tube 3014.
  • the first terminal of the first output capacitor unit 303 is connected, and the positive terminal of the second diode 3012 is connected to the second terminal of the second output capacitor unit 304 .
  • the negative input terminal 306 of the rectifier is connected to the positive terminal of the third diode 3021, the negative input terminal 306 of the rectifier is connected to the negative terminal of the fourth diode 3022, and the negative input terminal 306 of the rectifier is also connected to the positive terminal of the third diode 3021.
  • the first end of the third switch tube 3023 is connected, the third end of the third switch tube 3023 is connected to the third end of the fourth switch tube 3024, the negative end of the third diode 3021 is connected to the The first end of the first output capacitor unit 303 is connected, and the fourth diode 3022
  • the positive terminal of is connected to the second terminal of the second output capacitor unit 304.
  • the first end of the second switch transistor 3014 and the first end of the fourth switch transistor 3024 are connected to the second end of the first output capacitor unit 303 or the first end of the second output capacitor unit 304.
  • the first output capacitor unit 303 and the second output capacitor unit 304 may each include at least one capacitor.
  • the number of capacitors provided in each output capacitor unit is related to the parameters of the capacitor and the input voltage of the AC power supply 203 . For example, in an application scenario where the peak-to-peak voltage Vpp of the AC power supply 203 is 1150V and the DC voltage on the output side is 650V, the potential on each output capacitor unit is 325V.
  • the first output capacitor Two series-connected capacitors may be provided in the unit 303 and the second output capacitor unit 304 to reduce costs.
  • the first switching transistor 3013 and the second switching transistor 3014 are turned off.
  • the third switching transistor 3023 and the fourth switching transistor 3024 are closed to turn the target rectifier 211
  • the output voltage of is adjusted to the fourth voltage, and the sum of the output voltages of other rectifiers except the target rectifier 211 is adjusted to the fifth voltage; during the second period, the third switching tube 3023 and the fourth switching tube 3024 are turned off , the target rectifier 211 is controlled not to output a voltage, and the sum of the output voltages of other rectifiers except the target rectifier 211 is adjusted to the total voltage output by the power conversion circuit 200 when it is operating normally.
  • the first period is a period during which current flows from the input positive terminal of the target rectifier 211 to the input negative terminal.
  • the second period is a period during which the current flows from the input negative terminal to the input positive terminal of the target rectifier 211 .
  • the fourth voltage is less than The target rectifier 211 outputs a voltage when operating normally; the sum of the fourth voltage and the fifth voltage is equal to the total voltage output by the power conversion circuit 200 when operating normally.
  • each rectifier module can output: 2E, E, 0, -E, -2E, the following embodiments are all based on this example.
  • the control unit 202 sends a high-level pulse signal to the second terminal (ie, the control electrode) of the third switching tube 3023 and the fourth switching tube 3024, so that The third switch 3023 and the fourth switch 3024 remain closed, and the voltage reference value of the output capacitor unit corresponding to the target rectifier module is adjusted to half of the original voltage, so that the output voltage of the target rectifier 211 is adjusted to the fourth voltage, and the The sum of the output voltages of other rectifiers except the target rectifier 211 is adjusted to the fifth voltage.
  • the fourth voltage can be E
  • the fifth voltage can be 2E*(N-1)+E
  • the sum of the fourth voltage and the fifth voltage is 2E* N.
  • FIG. 4A is a schematic diagram of the current flow path in the first period when the first diode is short-circuited.
  • the third switching tube 3023 and the fourth switching tube 3024 are controlled to be closed, so that the short-circuited first diode 3011, the first output capacitor unit 303, the third switching tube 3023 and the fourth switching tube 3024 form a path. .
  • the control unit 202 does not send pulse signals to the second ends of the third switching tube 3023 and the fourth switching tube 3024, so that the third switching tube 3023 and the fourth switching tube 3024
  • the four switch tubes 3024 remain disconnected. Adjust the voltage reference value of the output capacitor unit corresponding to the target rectifier module to half of the original voltage, so that the target rectifier is controlled not to output a voltage, and the sum of the output voltages of other rectifiers except the target rectifier 211 is adjusted to the power conversion circuit 200The total voltage output during normal operation.
  • FIG. 4B is a schematic diagram of the current flow path in the second period when the first diode is short-circuited.
  • the third switching tube 3023 and the fourth switching tube 3024 are controlled to be disconnected, so that the short-circuited
  • the first diode 3011 and the third diode 3021 form a path.
  • Figure 4C is a voltage timing diagram of the target rectifier.
  • the output voltage of a single rectifier module is modulated from the original five levels to a positive voltage (fourth voltage) in the first period and zero output in the second period. Voltage.
  • the method used by the control unit 202 to control the power conversion circuit 200 to operate in different states may be a cyclic execution method of "first period to second period".
  • first period can be used as the starting period
  • second period can be used as the starting period.
  • the first switching transistor 3013 and the second switching transistor 3014 are disconnected.
  • the third switching transistor 3023 and the fourth switching transistor 3024 are disconnected to control the target rectifier.
  • 211 does not output voltage, and the sum of the output voltages of other rectifiers except the target rectifier 211 is adjusted to the total voltage output by the power conversion circuit 200 during normal operation; during the second period, the third switching tube 3023 and the fourth switching tube 3023 are closed.
  • the switching transistor 3024 adjusts the output voltage of the target rectifier 211 to the sixth voltage, and adjusts the sum of the output voltages of other rectifiers except the target rectifier 211 to the seventh voltage.
  • the sixth voltage is greater than the output voltage of the target rectifier when it is working normally; the sum of the sixth voltage and the seventh voltage is equal to the total voltage output by the power conversion circuit when it is working normally.
  • the control unit 202 does not send pulse signals to the second ends of the third switching tube 3023 and the fourth switching tube 3024, so that the third switching tube 3023 and the fourth switching tube 3024 remain disconnected and will be connected to the target.
  • the voltage reference value of the output capacitor unit corresponding to the rectifier module is adjusted to half of the original voltage, the target rectifier is controlled not to output a voltage, and the sum of the output voltages of other rectifiers except the target rectifier 211 is adjusted to the value when the power conversion circuit 200 is operating normally. The total voltage output.
  • FIG. 5A is a schematic diagram of the current flow path in the first period when the second diode is short-circuited.
  • the third switching tube 3023 and the fourth switching tube 3024 are controlled to be turned off, so that the short-circuited second diode 3012 and the fourth diode 3022 form a path.
  • the control unit 202 does not send pulse signals to the second ends of the third switching tube 3023 and the fourth switching tube 3024, so that the third switching tube 3023 and the fourth switching tube 3024 remain closed.
  • Adjust the voltage reference value of the output capacitor unit corresponding to the target rectifier module to half of the original voltage, adjust the output voltage of the target rectifier 211 to the sixth voltage, and adjust the output voltages of other rectifiers except the target rectifier 211
  • the sum is adjusted to the seventh voltage.
  • the sixth voltage can be -E
  • the seventh voltage can be -[2E*(N-1)+E]
  • the sum of the sixth voltage and the seventh voltage The sum is -2E*N.
  • FIG. 5B is a schematic diagram of the current flow path during the second period when the second diode is short-circuited.
  • the third switching tube 3023 and the fourth switching tube 3024 are controlled to close, so that the short-circuited third switching tube 3023 and the fourth switching tube 3024 are controlled to close.
  • the second diode 3012, the second output capacitor unit 304, the third switching tube 3023 and the fourth switching tube 3024 form a path.
  • Figure 5C is the second voltage timing diagram of the target rectifier.
  • the output voltage of a single rectifier module is modulated from the original five levels to a negative voltage (sixth voltage) in the first period and zero output in the second period. Voltage.
  • the third switching tube 3023 and the fourth switching tube 3024 are turned off.
  • the first switching tube 3013 and the second switching tube 3014 are turned off to control the target rectifier. 211 does not output voltage, and the sum of the output voltages of other rectifiers except the target rectifier 211 is adjusted to ensure that the power conversion circuit 200 works normally.
  • the sum of the output voltages of other rectifiers is adjusted to a ninth voltage; the eighth voltage is greater than the output voltage of the target rectifier when it is working normally; and the sum of the eighth voltage and the ninth voltage is equal to the output of the power conversion circuit when it is working normally. the total voltage.
  • the control unit 202 does not send pulse signals to the second ends of the first switching tube 3013 and the second switching tube 3014, so that the third switching tube 3023 and the fourth switching tube 3024 remain disconnected and will be connected to the target.
  • the voltage reference value of the output capacitor unit corresponding to the rectifier module is adjusted to half of the original voltage, the target rectifier 211 is controlled not to output a voltage, and the sum of the output voltages of other rectifiers except the target rectifier 211 is adjusted to ensure that the power conversion circuit 200 operates normally. the total output voltage.
  • FIG. 6A is a schematic diagram of the current flow path in the first period when the third diode is short-circuited.
  • the first switching tube 3013 and the second switching tube 3014 are controlled to be turned off, so that the short-circuited first diode 3011 and the third diode 3022 form a path.
  • the control unit 202 does not send pulse signals to the second ends of the third switching tube 3023 and the fourth switching tube 3024, so that the third switching tube 3023 and the fourth switching tube 3024 remain closed.
  • Adjust the voltage reference value of the output capacitor unit corresponding to the target rectifier module to half of the original voltage, adjust the output voltage of the target rectifier 211 to the eighth voltage, and adjust the output voltages of other rectifiers except the target rectifier 211
  • the sum is adjusted to the ninth voltage.
  • the eighth voltage can be -E
  • the ninth voltage can be -[2E*(N-1)+E]
  • the sum of the eighth voltage and the ninth voltage The sum is -2E*N.
  • FIG. 6B is a schematic diagram of the current flow path during the second period when the third diode is short-circuited.
  • the first switching tube 3013 and the second switching tube 3014 are controlled to be closed, so that the short-circuited third diode is closed.
  • the three diodes 3021, the first output capacitor unit 303, the first switch tube 3013 and the second switch tube 3014 form a path.
  • Figure 6C is the voltage timing diagram 3 of the target rectifier.
  • the output voltage of a single rectifier module is modulated from the original five levels to a negative voltage (eighth voltage) in the first period and zero output in the second period. Voltage.
  • the third switching transistor 3023 and the fourth switching transistor 3024 are turned off, and within the first period of time, the first switching transistor 3013 and the second switching transistor 3014 are closed, and the target rectifier 211
  • the output voltage of is adjusted to the tenth voltage, and the sum of the output voltages of other rectifiers except the target rectifier 211 is adjusted to the eleventh voltage; during the second period, the first switching tube 3013 and the second switching tube are disconnected 3014.
  • the control unit 202 sends a high-level pulse signal to the second end of the first switching tube 3013 and the second switching tube 3014, so that the first switching tube 3013 and the second switching tube 3014 remain closed, and the The voltage reference value of the output capacitor unit corresponding to the target rectifier module is adjusted to half of the original voltage, so that the output voltage of the target rectifier 211 is adjusted to the tenth voltage, and the sum of the output voltages of other rectifiers except the target rectifier 211 is adjusted. Adjust to the eleventh voltage. For example, when the maximum voltage that the rectifier module can output is 2E, the tenth voltage can be E, the eleventh voltage can be 2E*(N-1)+E, and the sum of the tenth voltage and the eleventh voltage is 2E*N.
  • FIG. 7A is a schematic diagram of the current flow path in the first period when the fourth diode is short-circuited.
  • the first switching tube 3013 and the second switching tube 3014 are controlled to be closed, so that the short-circuited fourth diode 3011, the second output capacitor unit 304, the first switching tube 3013 and the second switching tube 3014 form a path. .
  • the control unit 202 does not send pulse signals to the second ends of the first switching tube 3013 and the second switching tube 3014, so that the first switching tube 3013 and the second switching tube 3014 remain disconnected. Adjust the voltage reference value of the output capacitor unit corresponding to the target rectifier module to half of the original voltage, so that the target rectifier is controlled not to output a voltage, and the sum of the output voltages of other rectifiers except the target rectifier 211 is adjusted to the power conversion circuit 200The total voltage output during normal operation.
  • FIG. 7B is a schematic diagram of the current flow path in the second period when the fourth diode is short-circuited.
  • the first switching tube 3013 and the second switching tube 3014 are controlled to be disconnected, so that the short-circuited
  • the second diode 3012 and the fourth diode 3022 form a path.
  • Figure 7C is the voltage timing diagram 4 of the target rectifier.
  • the output voltage of a single rectifier module is modulated from the original five levels to a positive voltage (tenth voltage) in the first period and zero output in the second period. Voltage.
  • the power conversion circuit 200 After a diode short circuit occurs, the power conversion circuit 200 is almost unaffected and can ensure normal and smooth operation. Furthermore, the voltage waveform output by the power conversion circuit 200 has small distortion and is of good quality.
  • control unit 202 is also configured to reduce the load impedance connected to the target rectifier 211 .
  • the control unit 202 is also configured to reduce the load impedance connected to the target rectifier 211 .
  • the rectifier described in the embodiment of this application takes the application scenario of single-phase electricity as an example.
  • the power conversion circuit 200 is used for power conversion of three-phase electricity, refer to Figure 8, which shows the cascade connection of the rectifier. Schematic diagram of type topology.
  • Figure 8 shows the cascade connection of the rectifier.
  • Schematic diagram of type topology When a fault occurs in the power conversion circuit 200 of one phase, only the output voltage of the power conversion circuit 200 where the faulty diode is located needs to be adjusted.
  • the output voltage of the non-faulty corresponding power conversion circuit 200 and the modulated wave reference voltage are both No adjustment is required to achieve phase voltage balance, thus maintaining the operational stability of the cascaded power conversion circuit 200 .
  • the control unit when a short-circuit fault occurs in the diode, the control unit is used to reconfigure other devices in the target rectifier module to ensure that the power conversion circuit can continue to operate stably.
  • the control reduces The equivalent impedance of the downstream connection can stabilize the capacitor voltage, and the controllability of the power conversion circuit is guaranteed through capacitor power supply. Therefore, compared with the existing technology, using an external backup solution can reduce the cost and volume of the power circuit.
  • FIG. 9 is a schematic structural diagram of a power supply system.
  • the power supply system 900 includes N DC-to-DC converters 901 and In the power conversion circuit 200 described in the above embodiment, the N DC-DC converters 901 are connected to the N rectifiers 201 in the power conversion circuit 200 in one-to-one correspondence. Each DC-DC converter in the N DC-DC converters 901 is used to convert the first DC voltage output by the corresponding connected rectifier 201 into a second DC voltage; the first DC voltage is greater than the second DC voltage. DC voltage.

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Abstract

本申请提供一种功率变换电路以及供电***，功率变换电路包括N个整流器以及控制单元，每个整流器中包括两个整流模块，每个整流模块中包括多个二极管以及多个开关管；控制单元用于确定目标整流模块中的二极管短路时，断开目标整流模块中的开关管，将目标整流模块所在的目标整流器的输出电压调整为第一电压，将N个整流器中除目标整流器之外的其他整流器的输出电压之和调整为第二电压，在内部整流器的二极管发生短路故障后，通过对其他开关管的重新配置，使得整个功率变换电路能够继续稳定运行，相比现有技术采用外部备用的解决方案，能够降低功率变换电路的成本以及体积。

Description

一种功率变换电路以及供电***
相关申请的交叉引用
本申请要求在2022年05月13日提交中国专利局、申请号为202210522155.6、申请名称为“一种功率变换电路以及供电***”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及电力电子技术领域，特别涉及一种功率变换电路以及供电***。
背景技术
传统的不间断电源(uninterruptible power supply，UPS)由于高损耗、高成本，和***中的大容量低频变压器的存在，其在电源市场中的竞争力提升已遇到瓶颈，固态变压器(solid State Transformer，SST)是一种将电力电子变换技术和基于电磁感应原理的高频电能变换技术相结合，实现将一种电力特征的电能转变为另一种电力特征的电能的静止电气设备。通过固态变压器(又称整流器或功率变换电路)将中压交流电压转换为中压直流电压，并经过高频隔离的直流转直流电路转换之后得到低压直流电压，低压逆变器将低压直流电压变送至低压交流电压配电网。这种方式能够隔离中压电网与数据中心配网，电能质量高，并直接提供低压储能电池接口，且能够省去低功率密度的工频变压器。因此，该方案将成为未来中压UPS供电***的首选。
上述中压UPS供电***通常采用级联型拓扑，该级联型拓扑的功率变换电路采用级联H桥结构。但上述中压UPS供电***存在较大的不确定因素(出现故障)，因此稳定性较差，现有技术方案针对上述结构的故障维护主要包括以下几种方式：附加功率模块方法，特殊调制方法和共模电压信号注入方法。
1.附加功率模块方法：该方法可分为冷备用和热备用，主要依据附加的模块来保证级联H桥结构发生故障后能正常运行。然而，该方法需要新增额外的硬件设备，因此成本通常较高。
2.特殊调制方法：通过注入基波零序电压，修改三相输出电压参考，在新的电压参考下，重新利用特定谐波消除技术计算各个开关信号，从而在发生故障后能正常运行，但该方法会直接使故障子模块变为旁路，因此效果不好。
3.共模电压信号注入方法：在故障相的输出参考达到输出极限值时，短时间内注入直流偏移信号，利用故障子模块中的非故障开关，输出更多的电平。但该方法由于注入的共模电压分量较少，能应用的场景较少。
因此，基于上述方法存在的问题，亟需提出一种新型功率变换电路，在中压UPS供电***中的功率变换电路出现故障后，对功率变换电路进行故障处理，从而保证中压UPS供电***能继续稳定的运行。
发明内容
本申请提供一种功率变换电路以及供电***，在中压UPS供电***中的功率变换电路出现故障后，对功率变换电路进行故障处理，从而保证功率变换电路以及中压UPS供电***能继续稳定的运行。
第一方面，本申请提供一种功率变换电路，功率变换电路包括N个整流器以及控制单元，N为大于等于2的正整数；
每个整流器中包括两个整流模块，每个整流模块中包括多个二极管以及多个开关管；N个整流器中的每个整流器的输入端串联连接，N个整流器中的每个整流器的输出端并联连接；整流器，用于：接收交流供电源提供的交流电，将交流供电源提供的交流电转换为直流电压进行输出；控制单元，用于：确定目标整流模块中的二极管短路时，断开目标整流模块中的开关管，将目标整流模块所在的目标整流器的输出电压调整为第一电压，将N个整流器中除目标整流器之外的其他整流器的输出电压之和调整为第二电压，第一电压小于目标整流器正常工作时输出电压；第二电压大于其他整流器正常工作时输出电压之和。可选的，在本申请实施例中，整流器的类型可以为维也纳(Vienna)整流器，而整流器中的整流模块也可以为维也纳整流器结构中的其中一相维也纳整流模块。
利用本申请提供的功率变换电路，在内部整流器的二极管发生短路故障后，通过对其他开关管的重新配置，使得整个功率变换电路能够继续稳定运行，相比现有技术采用外部备用的解决方案，能够降低功率变换电路的成本以及体积。
为了便于控制，作为一种可能的实施方式，控制单元，具体用于：将其他整流器中的每个其他整流器的输出电压调整为第三电压，第三电压大于目标整流器正常工作时输出电压。
作为一种可能的实施方式，每个整流器，具体包括：第一整流模块、第二整流模块、第一输出电容单元以及第二输出电容单元；第一整流模块，包括：第一二极管、第二二极管、第一开关管、第二开关管；第二整流模块，包括：第三二极管、第四二极管、第三开关管、第四开关管；第一输出电容单元的第二端与第二输出电容单元的第一端连接；整流器的输入正端与第一二极管的正端连接，整流器的输入正端与第二二极管的负端连接，整流器的输入正端还与第一开关管的第一端连接，第一开关管的第三端与第二开关管的第三端连接，第一二极管的负端与第一输出电容单元的第一端连接，第二二极管的正端与第二输出电容单元的第二端连接；整流器的输入负端与第三二极管的正端连接，整流器的输入负端与第四二极管的负端连接，整流器的输入负端还与第三开关管的第一端连接，第三开关管的第三端与第四开关管的第三端连接，第三二极管的负端与第一输出电容单元的第一端连接，第四二极管的正端与第二输出电容单元的第二端连接；第二开关管的第一端以及第四开关管的第一端与第一输出电容单元的第二端连接。
作为一种可能的实施方式，控制单元，具体用于：在目标整流器中确定的第一二极管短路时，断开第一开关管和第二开关管，在第一时段内，闭合第三开关管和第四开关管，将目标整流器的输出电压调整为第四电压，除目标整流器之外的其他整流器的输出电压之和调整为第五电压；在第二时段内，断开第三开关管和第四开关管，控制目标整流器不输出电压，除目标整流器之外的其他整流器的输出电压之和调整为功率变换电路正常工作时输出的总电压；其中，第一时段为电流从目标整流器的输入正端流向输入负端的时段，第二时段为电流从目标整流器的输入负端流向输入正端的时段，第四电压小于目标整流器正常工作时输出电压；第四电压与第五电压之和等于功率变换电路正常工作时输出的总电压。
作为一种可能的实施方式，控制单元，具体用于：在目标整流器中确定的第二二极管短路时，断开第一开关管和第二开关管，在第一时段内，断开第三开关管和第四开关管，控制目标整流器不输出电压，除目标整流器之外的其他整流器的输出电压之和调整为功率变换电路正常工作时输出的总电压；在第二时段内，闭合第三开关管和第四开关管，将目标整流器的输出电压调整为第六电压，除目标整流器之外的其他整流器的输出电压之和调整为第七电压；其中，第一时段为电流从目标整流器的输入正端流向输入负端的时段，第二时段为电流从目标整流器的输入负端流向输入正端的时段，第六电压大于目标整流器正常工作时输出电压；第六电压与第七电压之和等于功率变换电路正常工作时输出的总电压。
作为一种可能的实施方式，控制单元，具体用于：在目标整流器中确定的第三二极管短路时，断开第三开关管和第四开关管，在第一时段内，断开第一开关管和第二开关管，控制目标整流器不输出电压，除目标整流器之外的其他整流器的输出电压之和调整为功率变换电路正常工作时输出的总电压；在第二时段内，闭合第一开关管和第二开关管，将目标整流器的输出电压调整为第八电压，除目标整流器之外的其他整流器的输出电压之和调整为第九电压；其中，第一时段为电流从目标整流器的输入正端流向输入负端的时段，第二时段为电流从目标整流器的输入负端流向输入正端的时段，第八电压大于目标整流器正常工作时输出电压；第八电压与第九电压之和等于功率变换电路正常工作时输出的总电压。
作为一种可能的实施方式，控制单元，具体用于：在目标整流器中确定的第四二极管短路时，断开第三开关管和第四开关管，在第一时段内，闭合第一开关管和第二开关管，将目标整流器的输出电压调整为第十电压，除目标整流器之外的其他整流器的输出电压之和调整为第十一电压；在第二时段内，断开第一开关管和第二开关管，控制目标整流器不输出电压，除目标整流器之外的其他整流器的输出电压之和调整为功率变换电路正常工作时输出的总电压；其中，第一时段为电流从目标整流器的输入正端流向输入负端的时段，第二时段为电流从目标整流器的输入负端流向输入正端的时段，第十电压大于目标整流器正常工作时输出电压；第十电压与第十一电压之和等于功率变换电路正常工作时输出的总电压。
作为一种可能的实施方式，本申请上述方面所描述整流器以单相电的应用场景进行举例，当功率变换电路用于三相电的功率转换时，在其中一相电的功率变换电路出现故障时，仅需调节出现故障的二极管所在的功率变换电路的输出电压，非故障所在的二极管对应功率变换电路的输出电压以及调制波参考电压值均无需调节，保持了级联功率变换电路的运行稳定性。
作为一种可能的实施方式，控制单元，还用于：降低与目标整流器连接的负载阻抗。通过调节目标整流器后端连接的负载阻抗大小，以保证目标整流器中的第一输出电容单元以及第二输出电容单元的电压稳定。
作为一种可能的实施方式，在每相邻两个整流器之间，上一个整流器的输入负端与下一个整流器的输入正端连接，第一个整流器的输入正端与交流供电源的供电正端连接，最后一个整流器的输入负端与交流供电源的供电负端连接；每个整流器的输出正端互相连接，每个整流器的输出负端互相连接。
第二方面，本申请提供一种供电***，供电***包括N个直流转直流DC-DC变换器以及如第一方面的功率变换电路，N个DC-DC变换器与功率变换电路中的N个整流器一一对应连接；N个DC-DC变换器中的每个DC-DC变换器，用于：将对应连接的整流器输 出的第一直流电压转换为第二直流电压；第一直流电压大于第二直流电压。
本申请的这些方面或其它方面在以下实施例的描述中会更加简明易懂。
附图说明
图1为一种基于固态变压器的UPS供电***结构图；
图2为一种功率变换电路的结构示意图；
图3为一种整流器的具体结构示意图；
图4A第一二极管短路时第一时段内的电流流通路径示意图；
图4B第一二极管短路时第二时段内的电流流通路径示意图；
图4C为目标整流器的电压时序示意图一；
图5A第二二极管短路时第一时段内的电流流通路径示意图；
图5B第二二极管短路时第二时段内的电流流通路径示意图；
图5C为目标整流器的电压时序示意图二；
图6A第三二极管短路时第一时段内的电流流通路径示意图；
图6B第三二极管短路时第二时段内的电流流通路径示意图；
图6C为目标整流器的电压时序示意图三；
图7A第四二极管短路时第一时段内的电流流通路径示意图；
图7B第四二极管短路时第二时段内的电流流通路径示意图；
图7C为目标整流器的电压时序示意图四；
图8为整流器的级联型拓扑结构示意图；
图9为一种供电***的结构示意图。
具体实施方式
为了使本申请的目的、技术方案和优点更加清楚，下面将结合附图对本申请作进一步地详细描述。然而，示例实施方式能够以多种形式实施，且不应被理解为限于在此阐述的实施方式；相反，提供这些实施方式使得本申请更全面和完整，并将示例实施方式的构思全面地传达给本领域的技术人员。在图中相同的附图标记表示相同或类似的结构，因而将省略对它们的重复描述。本申请中所描述的表达位置与方向的词，均是以附图为例进行的说明，但根据需要也可以做出改变，所做改变均包含在本申请保护范围内。本申请的附图仅用于示意相对位置关系不代表真实比例。
为了使本申请的目的、技术方案和优点更加清楚，下面将结合附图对本申请作进一步地详细描述。方法实施例中的具体操作方法也可以应用于装置实施例或***实施例中。需要说明的是，在本申请的描述中“至少一个”是指一个或多个，其中，多个是指两个或两个以上。鉴于此，本发明实施例中也可以将“多个”理解为“至少两个”。“和/或”，描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，字符“/”，如无特殊说明，一般表示前后关联对象是一种“或”的关系。另外，需要理解的是，在本申请的描述中，“第一”、“第二”等词汇，仅用于区分描述的目的，而不能理解为指示或暗示相对重要性，也不能理解为指示或暗示顺序。
需要指出的是，本申请实施例中“连接”指的是电连接，两个电学元件连接可以是两个电学元件之间的直接或间接连接。例如，A与B连接，既可以是A与B直接连接，也可以是A与B之间通过一个或多个其它电学元件间接连接，例如A与B连接，也可以是A与C直接连接，C与B直接连接，A与B之间通过C实现了连接。
近年来，随着电力容量的不断增加，数据中心、储能***、电动汽车充电站等不同应用领域对大规模的电源中心的需求越来越大。传统的不间断电源供电***由于高损耗、高成本，和供电***中的大容量低频变压器的存在，在不间断电源市场中的竞争力提升已遇到瓶颈。同时，随着中压电力电子开关器件的逐渐成熟，使用中压电力电子开关器件进行中压电力变换的方式已经成为一种可行且性能提升潜力巨大的方案。因此，通过高频变压器的应用，功率变换电路将中压交流供电输入变换成为低压直流电输出的中压UPS方案，将更加适用于多类型市场，并且可以适配这些市场中不断增加的电力容量以及配电***对较低规模、重量和成本的需求。
固态变压器是一种全新基于电力电子变换器的隔离交-直-交器件。图1为一种基于固态变压器的UPS供电***结构图。图1的结构首先通过交流转直流(alternating current-to-direct current converter，AC/DC)电路将中压交流电转换为中压直流电，经过高频隔离的直流转直流(direct current-to-direct current converter，DC/DC)电路转换得到低压直流电，后接低压逆变器将直流电变送至低压交流配电网中。此种结构能够隔离中压电网与数据中心的配网，电能质量高。但上述结构在出现故障时，难以有效的即时处理，现有的故障恢复方式在成本控制和应用场景上，都难以满足需求，基于上述方法存在的问题，亟需提出一种新型功率变换电路，在中压UPS供电***中的功率变换电路出现故障后，对功率变换电路进行故障处理，从而保证中压UPS供电***能继续稳定的运行。
本申请提供的功率变换电路，在内部整流器的二极管发生短路故障后，通过对其他开关管的重新配置，使得整个功率变换电路能够继续稳定运行，相比现有技术采用外部备用的解决方案，能够降低功率电路的成本以及体积。
参阅图2所示，图2为一种功率变换电路的结构示意图；本申请实施例提供的功率变换电路200可以包括：N个整流器201以及控制单元202，N为大于等于2的正整数；
每个整流器201中包括两个整流模块2010，每个整流模块2010中包括多个二极管以及多个开关管；N个整流器201中的每个整流器201的输入端串联连接，N个整流器201中的每个整流器201的输出端并联连接；
整流器201，用于：接收交流供电源203提供的交流电，将交流供电源203提供的交流电转换为直流电压进行输出。
控制单元202，用于：确定目标整流模块2110中的二极管短路时，断开目标整流模块2110中的开关管，将目标整流模块2110所在的目标整流器211的输出电压调整为第一电压，将N个整流器201中除目标整流器211之外的其他整流器的输出电压之和调整为第二电压，第一电压小于目标整流器211正常工作时输出电压；第二电压大于其他整流器201正常工作时输出电压之和。需要说明的是，在本申请实施例中，由于比较的电压为交流电压，因此，所比较的电压参数可以为电压的有效值或电压的峰峰值等，这里不做过多限定。
其中，本申请中的整流器201的结构，从二极管整流器演化而来，示例性的，整流器201可以为维也纳整流器结构，该结构中包括两个相同的单相整流模块，每个整流模块中包括两个二极管以及两个开关管，两个对顶的开关管可以等效为双向开关，从而来实现电 流的双向流动，整流器201的调制方法与二极管钳位多电平变换器相似，在特定时间下，整流器201分别将调制波钳位到五种电平，从而降低电流的畸变，减少开关动作次数。
需要说明的是，本申请中的整流器201可以但不限于上述实施例描述的具体结构，其他结构的整流器同样可以应用于本申请实施例中，这里不做具体限定。
其中，控制单元202可以与整流器201连接，从而实现对整流器201中的开关管的控制。
N个整流器201中的每个整流器201采用前串后并的结构，具体的，N个整流器201中的每个整流器201的输入端串联连接，N个整流器201中的每个整流器201的输出端并联连接，从而将交流供电源203提供的交流电转换为直流电压进行输出。
作为一种可能的实施方式，每相邻两个整流器之间，上一个整流器的输入负端与下一个整流器的输入正端连接，第一个整流器的输入正端与所述交流供电源的供电正端连接，最后一个整流器的输入负端与所述交流供电源的供电负端连接；每个整流器的输出正端互相连接，每个整流器的输出负端互相连接。
其中，本申请实施例中的整流器201中的开关管可以是金属氧化物半导体场效应晶体管(metal oxide semiconductor field effect transistor，MOSFET)，双极结型管(bipolar junction transistor，BJT)，绝缘栅双极型晶体管(insulated gate bipolar transistor，IGBT)，场效应晶体管(field effect transistor，FET)，碳化硅(SiC)或氮化镓(GaN)功率管等多种类型的开关管中的一种或多种，本申请实施例对此不再一一列举。每个开关管皆可以包括第一电极、第二电极和控制电极，其中，控制电极用于控制开关的导通或断开。当开关导通时，开关的第一电极和第二电极之间可以传输电流，当开关断开时，开关的第一电极和第二电极之间无法传输电流。以MOSFET为例，开关的控制电极为栅极，开关的第一电极可以是开关管的源极，第二电极可以是开关管的漏极，或者，第一电极可以是开关的漏极，第二电极可以是开关的源极。其中，所述主功率管的第一端和所述辅助功率管的第一端均可以为源(source)极，还可以为漏(drain)极，当第一端为源极时，第二端为漏极，而在第一端为漏极时，则第二端为源极。
本申请实施例中的控制单元202可以是通用中央处理器(central processing unit，CPU)，通用处理器，数字信号处理(digital signal processing，DSP)，专用集成电路(application specific integrated circuits，ASIC)，现场可编程门阵列(field programmable gate array，FPGA)或者其他可编程逻辑器件、晶体管逻辑器件、硬件部件或者其任意组合。其可以实现或执行结合本申请公开内容所描述的各种示例性的逻辑方框，模块和电路。控制单元202也可以是实现计算功能的组合，例如包括一个或多个微处理器组合，DSP和微处理器的组合等等控制单元202也可以包括多个控制子单元，每个控制子单元用于控制对应的整流器201，这里不做具体限定。
控制单元202通过实时监测各整流器201中的整流模块的二极管是否出现短路故障，来确定具体的控制策略，以保证整个功率变换电路200能够继续正常平稳运行。其中，在确定目标整流模块2110中的二极管短路时，先将故障所在的二极管对应的整流模块中的开关管断开，即断开目标整流模块2110中的开关管，并通过调节另一侧的开关管的开关状态，来维持功率变换电路200正常平稳运行，具体控制策略与交流电的电流方向以及二极管的故障位置有关，在下述实施例中进行详细描述，这里不做过多赘述。由于目标整流模块2110中的二极管出现故障，因此，目标整流模块2110其所在的目标整流器211难以输出整流器 正常工作时输出电压。通过调节目标整流模块2110的另一侧整流模块中的开关管的开关状态，以使目标整流器211的输出电压降低至第一电压。
其中，第一电压小于目标整流器211正常工作时输出电压，在不同电流方向下，因短路的二极管位置不同，所以第一电压的大小也不同。例如，第一电压可以为0，或者第一电压还可以为整流器正常工作时输出电压的一半等。需要说明的是，第一电压仅限定在整流器正常工作时输出电压以下，具体大小并不做限定。
在使目标整流器211的输出电压降低至第一电压后，需要补偿目标整流器211相比于正常工作时输出电压所少输出的部分，因此，可以增大其他整流器输出的电压之和来补偿目标整流器211的少输出的部分，从而能维持功率变换电路200正常平稳运行。具体的，将N个整流器201中除目标整流器211之外的其他整流器的输出电压之和调整为第二电压。
其中，第二电压大于其他整流器201正常工作时输出电压之和，在不同电流方向下，同样因短路的二极管连接位置不同，所以第二电压的大小也不同。例如，第二电压可以等于整个功率变换电路200正常工作时输出电压等。需要说明的是，第二电压仅限定在其他整流器201正常工作时输出的电压之和以上，具体大小并不做限定。
上述整流器201中的开关管的数量，可以与交流供电源203的交流电压大小以及开关管的耐压能力有关，在具体设计整流器201中的开关器件的数量时，在输入的交流电压较大而开关器件的耐压能力较低时，可以采用多个开关管串联的方式来对交流供电源203的交流电压进行分压，从而保证低耐压能力的开关管也能够正常工作。
此外，本申请实施例仅限定除目标整流器211之外的其他整流器的输出电压之和的大小，并不分别限定其他整流器中每个整流器的输出电压的大小，换言之，在同一个功率变换电路200中，每个整流器的输出电压可以相同也可以不同。其他整流器中的各个整流器的输出电压，也与整流器内部器件的参数有关，这里不做限定。
为了便于控制，作为一种可能的实施方式，控制单元202可以将所述其他整流器中的每个其他整流器的输出电压均调整为第三电压，所述第三电压大于所述目标整流器正常工作时输出电压。其中，其他整流器输出电压之和为N-1倍的第三电压，N-1倍的第三电压可以为第二电压。
参阅图3所示，图3为本申请的整流器的具体结构示意图；每个整流器的结构具体可以为：第一整流模块301、第二整流模块302、第一输出电容单元303以及第二输出电容单元304；所述第一整流模块301，包括：第一二极管3011、第二二极管3012、第一开关管3013、第二开关管3014；所述第二整流模块302，包括：第三二极管3021、第四二极管3022、第三开关管3023、第四开关管3024；所述第一输出电容单元303的第二端与所述第二输出电容单元304的第一端连接；整流器的输入正端305与所述第一二极管3011的正端连接，整流器的输入正端305与所述第二二极管3012的负端连接，整流器的输入正端305还与所述第一开关管3013的第一端连接，所述第一开关管3013的第三端与所述第二开关管3014的第三端连接，所述第一二极管3011的负端与所述第一输出电容单元303的第一端连接，所述第二二极管3012的正端与所述第二输出电容单元304的第二端连接。
整流器的输入负端306与所述第三二极管3021的正端连接，整流器的输入负端306与所述第四二极管3022的负端连接，整流器的输入负端306还与所述第三开关管3023的第一端连接，所述第三开关管3023的第三端与所述第四开关管3024的第三端连接，所述第三二极管3021的负端与所述第一输出电容单元303的第一端连接，所述第四二极管3022 的正端与所述第二输出电容单元304的第二端连接。
第二开关管3014的第一端以及第四开关管3024的第一端，与第一输出电容单元303的第二端连接，或者第二输出电容单元304的第一端连接。
其中，第一输出电容单元303以及第二输出电容单元304中可以分别包括至少一个电容，每个输出电容单元设置电容的数量与电容的参数以及交流供电源203的输入电压有关。例如，在交流供电源203的电压峰峰值Vpp＝1150V，输出侧直流电压为650V应用场景下，每个输出电容单元上的电势为325V，考虑到电容的耐压能力以及成本，第一输出电容单元303以及第二输出电容单元304中可以分别设置两个串联的电容，以降低成本。
基于上述图3所示的整流器的结构，在同一个整流器中，会存在四种不同位置的故障情况(一个整流器中同时出现两个及以上的二极管短路情况几乎不会出现)，针对不同位置的故障情况，控制单元202对应有不同的控制策略。
位置一(第一二极管3011短路)的故障控制策略：
在确定第一二极管3011短路时，断开第一开关管3013和第二开关管3014，在第一时段内，闭合第三开关管3023和第四开关管3024，将所述目标整流器211的输出电压调整为第四电压，除所述目标整流器211之外的其他整流器的输出电压之和调整为第五电压；在第二时段内，断开第三开关管3023和第四开关管3024，控制所述目标整流器211不输出电压，除所述目标整流器211之外的其他整流器的输出电压之和调整为功率变换电路200正常工作时输出的总电压。
第一时段为电流从所述目标整流器211的输入正端流向输入负端的时段，所述第二时段为电流从所述目标整流器211的输入负端流向输入正端的时段，所述第四电压小于所述目标整流器211正常工作时输出电压；所述第四电压与所述第五电压之和等于功率变换电路200正常工作时输出的总电压。
以第一输出电容单元303以及第二输出电容单元304中包括两个电容为例，若每个电容上的电压为E/2，则每个整流模块可以输出的电压存在五种可能的情况：2E、E、0、-E、-2E，下述实施例均据此为例。
在第一时段内(电流从输入正端流向输入负端)，控制单元202向第三开关管3023和第四开关管3024的第二端(即控制电极)发送高电平脉冲信号，以使第三开关管3023和第四开关管3024保持闭合，将与目标整流模块对应的输出电容单元的电压参考值调整为原电压的一半，使目标整流器211的输出电压调整为第四电压，并使除所述目标整流器211之外的其他整流器的输出电压之和调整为第五电压。示例性的，在整流模块可以输出的电压最大2E时，则第四电压可以为E，第五电压为2E*(N-1)+E，则第四电压与第五电压之和为2E*N。
参阅图4A所示，图4A为第一二极管短路时第一时段内的电流流通路径示意图。在第一时段内，控制第三开关管3023和第四开关管3024闭合，使短路的第一二极管3011、第一输出电容单元303、第三开关管3023以及第四开关管3024形成通路。
在第二时段内(电流从输入负端流向输入正端)，控制单元202不向第三开关管3023和第四开关管3024的第二端发送脉冲信号，以使第三开关管3023和第四开关管3024保持断开。将与目标整流模块对应的输出电容单元的电压参考值调整为原电压的一半，使控制目标整流器不输出电压，除所述目标整流器211之外的其他整流器的输出电压之和调整为功率变换电路200正常工作时输出的总电压。
参阅图4B所示，图4B为第一二极管短路时第二时段内的电流流通路径示意图，在第二时段内，控制第三开关管3023和第四开关管3024断开，使短路的第一二极管3011以及第三二极管3021形成通路。
参阅图4C所示，图4C为目标整流器的电压时序示意图一，单个整流器模块输出电压由原来的五电平调制，变为在第一时段正电压(第四电压)，在第二时段输出零电压。
需要说明的是，控制单元202用于控制功率变换电路200工作在不同状态的方式，可以是“第一时段～第二时段…”的循环执行方式。在具体循环时的起始时段不做具体限定，既可以采用第一时段作为起始时段，还可以采用第二时段作为起始时段，以下实施例不做过多赘述。
位置二(第二二极管3012短路)的故障控制策略：
在确定第二二极管3012短路时，断开第一开关管3013和第二开关管3014，在第一时段内，断开第三开关管3023和第四开关管3024，控制所述目标整流器211不输出电压，除所述目标整流器211之外的其他整流器的输出电压之和调整为功率变换电路200正常工作时输出的总电压；在第二时段内，闭合第三开关管3023和第四开关管3024，将所述目标整流器211的输出电压调整为第六电压，除所述目标整流器211之外的其他整流器的输出电压之和调整为第七电压。其中，第六电压大于所述目标整流器正常工作时输出电压；所述第六电压与所述第七电压之和等于功率变换电路正常工作时输出的总电压。
在第一时段内，控制单元202不向第三开关管3023和第四开关管3024的第二端发送脉冲信号，以使第三开关管3023和第四开关管3024保持断开，将与目标整流模块对应的输出电容单元的电压参考值调整为原电压的一半，控制目标整流器不输出电压，除所述目标整流器211之外的其他整流器的输出电压之和调整为功率变换电路200正常工作时输出的总电压。
参阅图5A所示，图5A为第二二极管短路时第一时段内的电流流通路径示意图。在第一时段内，控制第三开关管3023和第四开关管3024断开，使短路的第二二极管3012、以及第四二极管3022形成通路。
在第二时段内，控制单元202不向第三开关管3023和第四开关管3024的第二端发送脉冲信号，以使第三开关管3023和第四开关管3024保持闭合。将与目标整流模块对应的输出电容单元的电压参考值调整为原电压的一半，使目标整流器211的输出电压调整为第六电压，并使除所述目标整流器211之外的其他整流器的输出电压之和调整为第七电压。示例性的，在整流模块可以输出的电压最大2E时，则第六电压可以为-E，第七电压为-[2E*(N-1)+E]，则第六电压与第七电压之和为-2E*N。
参阅图5B所示，图5B为第二二极管短路时第二时段内的电流流通路径示意图，在第二时段内，控制第三开关管3023和第四开关管3024闭合，使短路的第二二极管3012、第二输出电容单元304、第三开关管3023以及第四开关管3024形成通路。
参阅图5C所示，图5C为目标整流器的电压时序示意图二，单个整流器模块输出电压由原来的五电平调制，变为在第一时段负电压(第六电压)，在第二时段输出零电压。
位置三(第三二极管3021短路)的故障控制策略：
在确定第三二极管3021短路时，断开第三开关管3023和第四开关管3024，在第一时段内，断开第一开关管3013和第二开关管3014，控制所述目标整流器211不输出电压，除所述目标整流器211之外的其他整流器的输出电压之和调整为功率变换电路200正常工 作时输出的总电压；在第二时段内，闭合第一开关管3013和第二开关管3014，将所述目标整流器211的输出电压调整为第八电压，除所述目标整流器211之外的其他整流器的输出电压之和调整为第九电压；所述第八电压大于所述目标整流器正常工作时输出电压；所述第八电压与所述第九电压之和等于功率变换电路正常工作时输出的总电压。
在第一时段内，控制单元202不向第一开关管3013和第二开关管3014的第二端发送脉冲信号，以使第三开关管3023和第四开关管3024保持断开，将与目标整流模块对应的输出电容单元的电压参考值调整为原电压的一半，控制目标整流器211不输出电压，除所述目标整流器211之外的其他整流器的输出电压之和调整为功率变换电路200正常工作时输出的总电压。
参阅图6A所示，图6A为第三二极管短路时第一时段内的电流流通路径示意图。在第一时段内，控制第一开关管3013和第二开关管3014断开，使短路的第一二极管3011、以及第三二极管3022形成通路。
在第二时段内，控制单元202不向第三开关管3023和第四开关管3024的第二端发送脉冲信号，以使第三开关管3023和第四开关管3024保持闭合。将与目标整流模块对应的输出电容单元的电压参考值调整为原电压的一半，使目标整流器211的输出电压调整为第八电压，并使除所述目标整流器211之外的其他整流器的输出电压之和调整为第九电压。示例性的，在整流模块可以输出的电压最大2E时，则第八电压可以为-E，第九电压为-[2E*(N-1)+E]，则第八电压与第九电压之和为-2E*N。
参阅图6B所示，图6B为第三二极管短路时第二时段内的电流流通路径示意图，在第二时段内，控制第一开关管3013和第二开关管3014闭合，使短路的第三二极管3021、第一输出电容单元303、第一开关管3013以及第二开关管3014形成通路。
参阅图6C所示，图6C为目标整流器的电压时序示意图三，单个整流器模块输出电压由原来的五电平调制，变为在第一时段负电压(第八电压)，在第二时段输出零电压。
位置四(第四二极管3022短路)的故障控制策略：
在确定第四二极管3022短路时，断开第三开关管3023和第四开关管3024，在第一时段内，闭合第一开关管3013和第二开关管3014，将所述目标整流器211的输出电压调整为第十电压，除所述目标整流器211之外的其他整流器的输出电压之和调整为第十一电压；在第二时段内，断开第一开关管3013和第二开关管3014，控制所述目标整流器211不输出电压，除所述目标整流器之外的其他整流器的输出电压之和调整为功率变换电路200正常工作时输出的总电压；所述第十电压大于所述目标整流器211正常工作时输出电压；所述第十电压与所述第十一电压之和等于功率变换电路200正常工作时输出的总电压。
在第一时段内，控制单元202向第一开关管3013和第二开关管3014的第二端发送高电平脉冲信号，以使第一开关管3013和第二开关管3014保持闭合，将与目标整流模块对应的输出电容单元的电压参考值调整为原电压的一半，使目标整流器211的输出电压调整为第十电压，并使除所述目标整流器211之外的其他整流器的输出电压之和调整为第十一电压。示例性的，在整流模块可以输出的电压最大2E时，则第十电压可以为E，第十一电压为2E*(N-1)+E，则第十电压与第十一电压之和为2E*N。
参阅图7A所示，图7A为第四二极管短路时第一时段内的电流流通路径示意图。在第一时段内，控制第一开关管3013和第二开关管3014闭合，使短路的第四二极管3011、第二输出电容单元304、第一开关管3013以及第二开关管3014形成通路。
在第二时段内，控制单元202不向第一开关管3013和第二开关管3014的第二端发送脉冲信号，以使第一开关管3013和第二开关管3014保持断开。将与目标整流模块对应的输出电容单元的电压参考值调整为原电压的一半，使控制目标整流器不输出电压，除所述目标整流器211之外的其他整流器的输出电压之和调整为功率变换电路200正常工作时输出的总电压。
参阅图7B所示，图7B为第四二极管短路时第二时段内的电流流通路径示意图，在第二时段内，控制第一开关管3013和第二开关管3014断开，使短路的第二二极管3012以及第四二极管3022形成通路。
参阅图7C所示，图7C为目标整流器的电压时序示意图四，单个整流器模块输出电压由原来的五电平调制，变为在第一时段正电压(第十电压)，在第二时段输出零电压。
利用上述实施例提供功率变换电路200，在二极管发生短路后，功率变换电路200几乎不受影响，能够保证继续正常平稳运行，且功率变换电路200输出的电压波形畸变小且质量很好。
作为一种可能的实施方式，所述控制单元202还用于：降低与所述目标整流器211连接的负载阻抗。通过调节目标整流器211后端连接的负载阻抗大小，以保证目标整流器211中的第一输出电容单元303以及第二输出电容单元304的电压稳定。
需要说明的是，本申请实施例所描述整流器以单相电的应用场景进行举例，当功率变换电路200用于三相电的功率转换时，参阅图8所示，图8为整流器的级联型拓扑结构示意图。在其中某一相电的功率变换电路200出现故障时，仅需调节出现故障的二极管所在的功率变换电路200的输出电压，非故障相对应功率变换电路200的输出电压以及调制波参考电压值均无需调节，以实现相电压平衡，保持了级联功率变换电路200的运行稳定性。
利用本申请实施例提供的功率变换电路，在其中的二极管发生短路故障时，利用控制单元对除目标整流模块中的其他器件进行重新配置，以保证功率变换电路能继续稳定运行，此外，控制降低后级连接的等效阻抗，能稳定电容电压，通过电容供电使功率变换电路的可控性得到保障，因此相比现有技术采用外部备用的解决方案，能够降低功率电路的成本以及体积。
基于同样的发明构思，本申请还提供一种供电***，参阅图9所示，图9为一种供电***的结构示意图，所述供电***900包括N个直流转直流DC-DC变换器901以及上述实施例所述的功率变换电路200，N个DC-DC变换器901与功率变换电路200中的N个整流器201一一对应连接。所述N个DC-DC变换器901中的每个DC-DC变换器用于将对应连接的整流器201输出的第一直流电压转换为第二直流电压；所述第一直流电压大于所述第二直流电压。
尽管已描述了本申请的优选实施例，但本领域内的技术人员一旦得知了基本创造性概念，则可对这些实施例作出另外的变更和修改。所以，所附权利要求意欲解释为包括优选实施例以及落入本申请范围的所有变更和修改。
显然，本领域的技术人员可以对本申请实施例进行各种改动和变型而不脱离本申请实施例的范围。这样，倘若本申请实施例的这些修改和变型属于本申请权利要求及其等同技术的范围之内，则本申请也意图包含这些改动和变型在内。

Claims (10)

  1. 一种功率变换电路，其特征在于，所述功率变换电路包括N个整流器以及控制单元，所述N为大于等于2的正整数；
    每个整流器中包括两个整流模块，每个整流模块中包括多个二极管以及多个开关管；所述N个整流器中的每个整流器的输入端串联连接，所述N个整流器中的每个整流器的输出端并联连接；
    所述整流器，用于：接收交流供电源提供的交流电，将所述交流供电源提供的交流电转换为直流电压进行输出；
    所述控制单元，用于：确定目标整流模块中的二极管短路时，断开所述目标整流模块中的开关管，将所述目标整流模块所在的目标整流器的输出电压调整为第一电压，将所述N个整流器中除所述目标整流器之外的其他整流器的输出电压之和调整为第二电压，所述第一电压小于所述目标整流器正常工作时输出电压；所述第二电压大于所述其他整流器正常工作时输出电压之和。
  2. 根据权利要求1所述的电路，其特征在于，所述控制单元，具体用于：将所述其他整流器中的每个其他整流器的输出电压调整为第三电压，所述第三电压大于所述目标整流器正常工作时输出电压。
  3. 根据权利要求1或2所述的电路，其特征在于，每个整流器，具体包括：
    第一整流模块、第二整流模块、第一输出电容单元以及第二输出电容单元；
    所述第一整流模块，包括：第一二极管、第二二极管、第一开关管、第二开关管；
    所述第二整流模块，包括：第三二极管、第四二极管、第三开关管、第四开关管；
    所述第一输出电容单元的第二端与所述第二输出电容单元的第一端连接；
    整流器的输入正端与所述第一二极管的正端连接，整流器的输入正端与所述第二二极管的负端连接，整流器的输入正端还与所述第一开关管的第一端连接，所述第一开关管的第三端与所述第二开关管的第三端连接，所述第一二极管的负端与所述第一输出电容单元的第一端连接，所述第二二极管的正端与所述第二输出电容单元的第二端连接；
    整流器的输入负端与所述第三二极管的正端连接，整流器的输入负端与所述第四二极管的负端连接，整流器的输入负端还与所述第三开关管的第一端连接，所述第三开关管的第三端与所述第四开关管的第三端连接，所述第三二极管的负端与所述第一输出电容单元的第一端连接，所述第四二极管的正端与所述第二输出电容单元的第二端连接；
    所述第二开关管的第一端以及所述第四开关管的第一端与所述第一输出电容单元的第二端连接。
  4. 根据权利要求3所述的电路，其特征在于，所述控制单元，具体用于：
    在所述目标整流器中确定的第一二极管短路时，断开第一开关管和第二开关管，在第一时段内，闭合第三开关管和第四开关管，将所述目标整流器的输出电压调整为第四电压，除所述目标整流器之外的其他整流器的输出电压之和调整为第五电压；在第二时段内，断开第三开关管和第四开关管，控制所述目标整流器不输出电压，除所述目标整流器之外的 其他整流器的输出电压之和调整为功率变换电路正常工作时输出的总电压；
    其中，所述第一时段为电流从所述目标整流器的输入正端流向输入负端的时段，所述第二时段为电流从所述目标整流器的输入负端流向输入正端的时段，所述第四电压小于所述目标整流器正常工作时输出电压；所述第四电压与所述第五电压之和等于功率变换电路正常工作时输出的总电压。
  5. 根据权利要求3所述的电路，其特征在于，所述控制单元，具体用于：
    在所述目标整流器中确定的第二二极管短路时，断开第一开关管和第二开关管，在第一时段内，断开第三开关管和第四开关管，控制所述目标整流器不输出电压，除所述目标整流器之外的其他整流器的输出电压之和调整为功率变换电路正常工作时输出的总电压；在第二时段内，闭合第三开关管和第四开关管，将所述目标整流器的输出电压调整为第六电压，除所述目标整流器之外的其他整流器的输出电压之和调整为第七电压；
    其中，所述第一时段为电流从所述目标整流器的输入正端流向输入负端的时段，所述第二时段为电流从所述目标整流器的输入负端流向输入正端的时段，所述第六电压大于所述目标整流器正常工作时输出电压；所述第六电压与所述第七电压之和等于功率变换电路正常工作时输出的总电压。
  6. 根据权利要求3所述的电路，其特征在于，所述控制单元，具体用于：
    在所述目标整流器中确定的第三二极管短路时，断开第三开关管和第四开关管，在第一时段内，断开第一开关管和第二开关管，控制所述目标整流器不输出电压，除所述目标整流器之外的其他整流器的输出电压之和调整为功率变换电路正常工作时输出的总电压；在第二时段内，闭合第一开关管和第二开关管，将所述目标整流器的输出电压调整为第八电压，除所述目标整流器之外的其他整流器的输出电压之和调整为第九电压；
    其中，所述第一时段为电流从所述目标整流器的输入正端流向输入负端的时段，所述第二时段为电流从所述目标整流器的输入负端流向输入正端的时段，所述第八电压大于所述目标整流器正常工作时输出电压；所述第八电压与所述第九电压之和等于功率变换电路正常工作时输出的总电压。
  7. 根据权利要求3所述的电路，其特征在于，所述控制单元，具体用于：
    在所述目标整流器中确定的第四二极管短路时，断开第三开关管和第四开关管，在第一时段内，闭合第一开关管和第二开关管，将所述目标整流器的输出电压调整为第十电压，除所述目标整流器之外的其他整流器的输出电压之和调整为第十一电压；在第二时段内，断开第一开关管和第二开关管，控制所述目标整流器不输出电压，除所述目标整流器之外的其他整流器的输出电压之和调整为功率变换电路正常工作时输出的总电压；
    其中，所述第一时段为电流从所述目标整流器的输入正端流向输入负端的时段，所述第二时段为电流从所述目标整流器的输入负端流向输入正端的时段，所述第十电压大于所述目标整流器正常工作时输出电压；所述第十电压与所述第十一电压之和等于功率变换电路正常工作时输出的总电压。
  8. 根据权利要求1-7任一所述的电路，其特征在于，所述控制单元，还用于：降低与 所述目标整流器连接的负载阻抗。
  9. 根据权利要求1-8任一所述的电路，其特征在于，在所述每相邻两个整流器之间，上一个整流器的输入负端与下一个整流器的输入正端连接，第一个整流器的输入正端与所述交流供电源的供电正端连接，最后一个整流器的输入负端与所述交流供电源的供电负端连接；每个整流器的输出正端互相连接，每个整流器的输出负端互相连接。
  10. 一种供电***，其特征在于，所述供电***包括N个直流转直流DC-DC变换器以及如权利要求1-9任一所述的功率变换电路，N个DC-DC变换器与功率变换电路中的N个整流器一一对应连接；
    所述N个DC-DC变换器中的每个DC-DC变换器，用于：将对应连接的整流器输出的第一直流电压转换为第二直流电压；所述第一直流电压大于所述第二直流电压。
PCT/CN2023/080881 2022-05-13 2023-03-10 一种功率变换电路以及供电*** WO2023216705A1 (zh)

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