CN110098598B - Reverse-blocking type hybrid submodule with fault blocking capability and fault blocking method thereof - Google Patents

Reverse-blocking type hybrid submodule with fault blocking capability and fault blocking method thereof Download PDF

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CN110098598B
CN110098598B CN201910403040.3A CN201910403040A CN110098598B CN 110098598 B CN110098598 B CN 110098598B CN 201910403040 A CN201910403040 A CN 201910403040A CN 110098598 B CN110098598 B CN 110098598B
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switch unit
capacitor
fault
fault current
blocking
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CN110098598A (en
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罗永捷
宋勇辉
蒲羿
欧阳金鑫
熊小伏
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Chongqing University
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
    • H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
    • H02H7/122—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for inverters, i.e. dc/ac converters
    • H02H7/1225—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for inverters, i.e. dc/ac converters responsive to internal faults, e.g. shoot-through

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  • Power Engineering (AREA)
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Abstract

The invention discloses a reverse-resistance type hybrid submodule with fault blocking capability, which comprises a first half-bridge submodule formed by a first switch unit, a second switch unit and a first capacitor, and a second half-bridge submodule formed by a third switch unit, a fourth switch unit, a fifth switch unit and a second capacitorA sub-module; the fourth switching unit adopts a structural form that two insulated gate bipolar transistors are reversely connected in parallel, so that the fourth switching unit has a bidirectional conduction-bidirectional blocking function; the other switch units adopt the structural form that the insulated gate bipolar transistor is connected with the freewheeling diode in reverse parallel, so that the bidirectional conduction-unidirectional blocking function is realized; can output 0 and U by switching the working modeC、2UCThree working voltages, which can provide 2U for positive and negative fault currentCThe back emf of (a) is blocked. And a fault blocking method is also provided, each switch unit is switched off, fault current charges the first capacitor and the second capacitor in series, and counter electromotive force is generated in the charging process to block the fault current.

Description

Reverse-blocking type hybrid submodule with fault blocking capability and fault blocking method thereof
Technical Field
The invention relates to the field of modular multilevel converters, in particular to a reverse-resistance type hybrid submodule with fault blocking capability for a multilevel converter. And also relates to a fault current blocking method.
Background
Modular multilevel converters have developed at a rapid pace since 2002 as proposed by Marquardt r. Different from the traditional two-level VSC, the MMC has the advantages of low switching frequency, small loss, good waveform quality and the like and is widely applied to the actual flexible direct-current transmission engineering. When a direct-current side bipolar short-circuit fault occurs in a system, the fault current cannot be blocked by the MMC based on the traditional HBSM due to the follow current effect of the diode, and the system is greatly damaged. Therefore, MMC direct current fault blocking is achieved, a sub-module topological structure with fault blocking capacity is provided, and the method belongs to the popular field of domestic and foreign research. Although a full-bridge sub-module topology (FBSM) block can achieve a fault current blocking capability, the number of switching devices required for outputting a unit level is too large, which results in a serious loss. In order to solve the problem of excessive switching devices, some researchers have proposed a Clamped dual sub-module (CDSM) topology capable of reducing the number of switching devices, and a fault blocking principle thereof and fault current characteristics under various fault conditions of an ac side fault, but no mention is made on how to block the ac fault current and a system protection method. In addition, although the CDSM can obviously block fault current, the fault blocking capability is different due to different current directions because two different capacitance connection modes exist in the fault blocking process. In addition, a student module topological structure capable of effectively blocking fault current is provided, the number of the submodule modules can be reduced to half of that of the submodule modules of the CDSM topological structure, the number of devices required by unit output level is high, two switch devices which are always conducted exist under normal working conditions, and loss is serious.
In summary, the sub-module topologies with fault blocking capability all have the problems of large number of devices, serious loss, different fault blocking capabilities in different current directions, and the like, and how to make the fault blocking capability of the sub-module in different current flow directions the same without increasing the number of devices required by a single output level in the sub-module does not exist at present.
Disclosure of Invention
In view of the above-mentioned deficiencies of the prior art, the present invention provides a reverse blocking type hybrid sub-module topology with fault blocking capability, which improves the fault blocking capability without increasing the number of devices required by a single output level in the sub-module, and makes the fault blocking capabilities of the sub-modules in different current flow directions the same.
In order to solve the technical problems, the technical scheme of the invention is as follows: a reverse-resistance type hybrid submodule with fault blocking capability comprises a first half-bridge submodule, a second half-bridge submodule, a first clamping diode and a second clamping diode; the first half-bridge submodule comprises a first switch unit, a second switch unit and a first capacitor; the second half-bridge submodule comprises a third switching unit, a fourth switching unit, a fifth switching unit and a second capacitor; the parameters of the first capacitor and the second capacitor are completely the same, and the voltage reference values of the first capacitor and the second capacitor are both UC；
The first switch unit, the second switch unit, the third switch unit and the fifth switch unit all adopt a structural form that the insulated gate bipolar transistors are connected with the fly-wheel diodes in reverse parallel, so that the bidirectional conduction-unidirectional blocking function is achieved, the conduction direction of the insulated gate bipolar transistors is taken as the forward conduction direction, the conduction direction of the fly-wheel diodes is taken as the reverse conduction direction, and only the forward conduction direction can be turned off; the first switch unit, the second switch unit, the third switch unit and the fifth switch unit are switched on in two directions, and the switching off is carried out in the forward direction;
the fourth switching unit adopts a structural form that two insulated gate bipolar transistors are reversely connected in parallel, so that the fourth switching unit has a bidirectional conduction-bidirectional blocking function; the on state of the fourth switch unit is bidirectional on, and the off state is bidirectional off;
the first switch unit and the second switch unit are connected in series in the forward direction and then connected in parallel with the first capacitor, namely the forward conduction directions of the first switch unit and the second switch unit are consistent, the positive terminal of the first capacitor is connected with the first switch unit, and the negative terminal of the first capacitor is connected with the second switch unit; the forward conduction direction of the third switch unit is consistent with the forward conduction direction of the first switch unit; the third switching unit and the fourth switching unit are connected in series and then are connected in parallel with the first clamping diode, the anode of the first clamping diode is connected with the fourth switching unit, and the cathode of the first clamping diode is connected with the third switching unit; the negative end of the second capacitor is reversely connected with the fifth switch unit in series, the anode of the first clamping diode is connected with the fifth switch unit, and the cathode of the first clamping diode is connected with the positive end of the second capacitor; the positive end of the first capacitor is connected with the negative end of the second capacitor after being connected with the second clamping diode in series, the anode of the second clamping diode is connected with the negative end of the second capacitor, the cathode of the second clamping diode is connected with the positive end of the first capacitor, and the negative end of the first capacitor is connected between the third switch unit and the fourth switch unit, so that the first half-bridge sub-module and the second half-bridge sub-module are connected in series;
the first power supply end is connected between the first switch unit and the second switch unit, and the connection points of the fourth switch unit, the fifth switch unit and the first clamping diode are connected with the second power supply end.
Further, 0 and U can be output by switching the working modeC、2UCThree operating voltages.
Further, there are four kinds of working modules:
working mode 1: the first switch unit, the third switch unit and the fifth switch unit are turned off, and the second switch unit and the fourth switch unit are turned on, so that the first capacitor and the second capacitor are both bypassed, and the external output voltage is 0;
the working mode 2 is as follows: the second switch unit, the third switch unit and the fifth switch unit are turned off, and the first switch unit and the fourth switch unit are turned on, so that the first capacitor is connected in series into the circuit, the second capacitor is bypassed, and the external output voltage is UC；
Working mode 3: the first switch unit and the fourth switch unit are disconnected, the second switch unit, the third switch unit and the fifth switch unit are connected, so that the first capacitor is bypassed, the second capacitor is connected in series in the circuit, and the external output voltage is UC；
The working mode 4 is as follows: the second switch unit and the fourth switch unit are turned off, and the first switch unit, the third switch unit and the fifth switch unit are turned on, so that the first capacitor and the second capacitor are connected in series in the circuit, and the external output voltage is 2UC。
Further, 2U can be providedCThe back emf of (a) blocks the fault current.
The invention also provides a fault blocking method adopting the reverse blocking type hybrid submodule with the fault blocking capability, which is characterized by comprising the following steps of:
step 1: when a fault occurs, the first switch unit, the second switch unit, the third switch unit, the fourth switch unit and the fifth switch unit are turned off;
step 2: judging the fault current direction: if the fault current flows from the first power supply end, the fault current is a forward fault current, and the step 3 is carried out; if the fault current flows from the second power supply end, the fault current is reverse fault current, and the step 4 is carried out;
and step 3: forward fault current sequentially passes through the freewheeling diode of the first switch unit, the first capacitor, the freewheeling diode of the third switch, the second capacitor and the freewheeling diode of the fifth switch unit and flows out of the second power supply end, so that the forward fault current charges the first capacitor and the second capacitor which are connected in series, and the first capacitor and the second capacitor generate back electromotive force to block the fault current in the charging process;
and 4, step 4: the reverse fault current sequentially passes through the first clamping diode, the second capacitor, the second clamping diode, the first capacitor and the freewheeling diode of the second switch unit and flows out of the first power supply end, so that the reverse fault current charges the first capacitor and the second capacitor which are connected in series, and the first capacitor and the second capacitor generate counter electromotive force to block the fault current in the charging process.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention changes the structure of one switch unit, namely a fourth switch unit adopts a structural form that two insulated gate bipolar transistors are reversely connected in parallel to form the switch unit with the bidirectional conduction-bidirectional blocking function, and correspondingly adjusts the circuit structure, thereby ensuring that a first capacitor and a second capacitor can be simultaneously connected in series in a charging loop to generate reverse electromotive force when forward fault current or reverse fault current occurs, improving the fault blocking capability without increasing a capacitor device, and providing the same blocking capability for the forward fault current and the reverse fault current.
2. Under the condition that the reference voltage of the capacitor is the same, the blocking capability of the conventional CDSM on the forward fault current is 2UCBlocking capability for reverse fault current of 0.5UC. However, the blocking capability of the invention for positive and negative fault currents is 2UCTherefore, the fault blocking capability of the invention to the reverse current is greatly improved.
3. Although the conventional CDSM can also output 3 working levels, the output of each working level requires three switch units to be simultaneously conducted, and the working mode 1 and the working mode 2 of the invention only require two switch units to be conducted, so that the loss can be reduced.
Drawings
FIG. 1 is a schematic of the topology of a prior art CDSM;
FIG. 2 is a schematic diagram of a topology of a reverse blocking hybrid sub-module with fault blocking capability in this embodiment;
fig. 3 is a schematic diagram of a current flow path when a forward fault current flows into a sub-module in the fault blocking method of the present invention;
fig. 4 is a schematic view of a current flow path when a reverse fault current flows into the sub-module in the fault blocking method of the present invention.
Detailed Description
Referring to fig. 2, a reverse blocking type hybrid submodule with fault blocking capability includes a first half-bridge submodule, a second half-bridge submodule, a first clamping diode D1 and a second clamping diode D2; the first half-bridge submodule comprises a first switch unit, a second switch unit and a first capacitor C1; the second half-bridge submodule comprises a third switching unit, a fourth switching unit, a fifth switching unit and a second capacitor C2; the parameters of the first capacitor C1 and the second capacitor C2 are identical, and the voltage reference values of the first capacitor C1 and the second capacitor C2 are both UC。
The first switch unit, the second switch unit, the third switch unit and the fifth switch unit all adopt a structural form that the insulated gate bipolar transistors are connected with the fly-wheel diodes in reverse parallel, so that the bidirectional conduction-unidirectional blocking function is achieved, the conduction direction of the insulated gate bipolar transistors is taken as the forward conduction direction, the conduction direction of the fly-wheel diodes is taken as the reverse conduction direction, and only the forward conduction direction can be turned off; the first switch unit, the second switch unit, the third switch unit and the fifth switch unit are turned on in two directions, and the turn-off is turned off in the forward direction.
The first switch unit comprises an insulated gate bipolar transistor VT1 and a freewheeling diode VD1, wherein the grid electrode of the insulated gate bipolar transistor VT1 is used for receiving a control signal, the anode electrode of the freewheeling diode VD1 is connected with the emission set of the insulated gate bipolar transistor VT1, and the cathode electrode of the freewheeling diode VD1 is connected with the collector electrode of the insulated gate bipolar transistor VT1, so that reverse parallel connection is formed.
The second switch unit comprises an insulated gate bipolar transistor VT2 and a freewheeling diode VD2, the grid electrode of the insulated gate bipolar transistor VT2 is used for receiving a control signal, the anode electrode of the freewheeling diode VD2 is connected with the emission set of the insulated gate bipolar transistor VT2, and the cathode electrode of the freewheeling diode VD2 is connected with the collector electrode of the insulated gate bipolar transistor VT2, so that reverse parallel connection is formed.
The third switching unit comprises an insulated gate bipolar transistor VT3 and a freewheeling diode VD3, wherein the grid electrode of the insulated gate bipolar transistor VT3 is used for receiving a control signal, the anode electrode of the freewheeling diode VD3 is connected with the emission set of the insulated gate bipolar transistor VT3, and the cathode electrode of the freewheeling diode VD3 is connected with the collector electrode of the insulated gate bipolar transistor VT3, so that reverse parallel connection is formed.
The fifth switch unit comprises an insulated gate bipolar transistor VT6 and a freewheeling diode VD4, wherein the anode of the freewheeling diode VD4 is connected with the emission set of the insulated gate bipolar transistor VT6, and the cathode of the freewheeling diode VD4 is connected with the collector of the insulated gate bipolar transistor VT6, so that the reverse parallel connection is formed.
The fourth switching unit adopts a structural form that two insulated gate bipolar transistors are reversely connected in parallel, so that the fourth switching unit has a bidirectional conduction-bidirectional blocking function; the on state of the fourth switching unit is bidirectional on, and the off state thereof is bidirectional off.
The fourth switch unit comprises an insulated gate bipolar transistor VT4 and an insulated gate bipolar transistor VT5, wherein a collector electrode and an emission set of the insulated gate bipolar transistor VT4 are respectively connected with an emission set and a collector electrode of the insulated gate bipolar transistor VT5, so that anti-parallel connection is formed.
The first switch unit and the second switch unit are connected in series in the forward direction and then connected in parallel with a first capacitor C1, namely the forward conduction directions of the first switch unit and the second switch unit are consistent, the emission set of the insulated gate bipolar transistor VT1 is connected with the collector of the insulated gate bipolar transistor VT2, so that the first switch unit and the second switch unit form forward series connection, the positive end of the first capacitor C1 is connected with the first switch unit, and the negative end of the first capacitor C1 is connected with the second switch unit; the forward conduction direction of the third switch unit is consistent with the forward conduction direction of the first switch unit; the third switching unit and the fourth switching unit are connected in series and then connected in parallel with a first clamping diode D1, the anode of the first clamping diode D1 is connected with the fourth switching unit, and the cathode of the first clamping diode D1 is connected with the third switching unit; the negative terminal of the second capacitor C2 is connected in reverse series with the fifth switching unit (i.e. the negative terminal of the second capacitor C2 is connected in reverse series with the emitter set of the igbt VT 6), and the anode of the first clamping diode D1 is connected with the fifth switching unit, and the cathode of the first clamping diode D1 is connected with the positive terminal of the second capacitor C2; the positive end of the first capacitor C1 is connected with the negative end of the second capacitor C2 after being connected with the second clamping diode D2 in series, the anode of the second clamping diode D2 is connected with the negative end of the second capacitor C2, the cathode of the second clamping diode D2 is connected with the positive end of the first capacitor C1, and the negative end of the first capacitor C1 is connected between the third switching unit and the fourth switching unit, so that the first half-bridge submodule and the second half-bridge submodule are connected in series.
The first power supply end is connected between the first switch unit and the second switch unit, and the connection points of the fourth switch unit, the fifth switch unit and the first clamping diode D1 are connected with the second power supply end.
Referring to fig. 2, the reverse blocking type hybrid sub-module with fault blocking capability of the present invention has the following 4 operation modes, and 0 and U can be output by switching the operation modesC、2UCThree operating voltages:
working mode 1: the first switch unit, the third switch unit and the fifth switch unit are turned off (i.e., VT1, VT3 and VT6 are turned off), and the second switch unit and the fourth switch unit are turned on, so that the first capacitor C1 and the second capacitor C2 are both bypassed, and the external output voltage is 0.
The working mode 2 is as follows: the second, third and fifth switching units are turned off (i.e., VT2, VT3, VT6 are turned off), the first and fourth switching units are turned on, so that the first capacitor C1 is connected in series to the circuit,the second capacitor C2 is bypassed, and the external output voltage is UC。
Working mode 3: the first switch unit and the fourth switch unit are turned off (i.e. VT1, VT4, VT5 are turned off), the second switch unit, the third switch unit and the fifth switch unit are turned on, so that the first capacitor C1 is bypassed, the second capacitor C2 is connected in series in the circuit, and the external output voltage is UC。
The working mode 4 is as follows: the second switch unit and the fourth switch unit are turned off (i.e. VT2, VT4, VT5 are turned off), the first switch unit, the third switch unit and the fifth switch unit are turned on, so that the first capacitor C1 and the second capacitor C2 are both connected in series in the circuit, and the external output voltage is 2UC。
Although 3 kinds of operation levels can be output for the conventional CDSM, the output of each operation level requires three switch units to be turned on simultaneously, as shown in fig. 1: 1) conventional CDSM outputs 2UCThe operating levels of (1) require that VT1, VT7 and VT4 are conductive; 2) conventional CDSM output UCThe working level of (2) requires that VT1, VT6, VT4 are turned on; 3) the conventional operating level of CDSM output 0 requires VT2, VT6, VT4 to be on. Therefore, the conventional CDSM needs to require VT4 to be always on, the output of each working level needs to have three switch units to be simultaneously turned on, and the working mode 1 and the working mode 2 of the invention only need two switch units to be turned on, so that the loss can be reduced.
Referring to fig. 1, a conventional fault blocking capability analysis of CDSM:
when a forward fault current occurs, VT1, VT2, VT4, VT6 and VT7 are all turned off, the forward fault current flows through a freewheeling diode VD1, a capacitor C1, a freewheeling diode VD4, a capacitor C2 and a freewheeling diode VD7 in sequence, the capacitors C1 and C2 are charged in series, and 2U can be generated to the maximum extentCBack electromotive force of (3).
When reverse fault current occurs, VT1, VT2, VT4, VT6 and VT7 are all turned off, and the reverse fault current is divided into two branches from a freewheeling diode VD 6: the first branch passes through a diode VD3, a capacitor C1 and then a freewheeling diode VD 2; the second branch passes through a capacitor C2, a diode VD5 and then a freewheeling diode VD 2; the capacitors C1 and C2 are charged in parallel, and 0.5U can be generated at mostCBack electromotive force of (3).
According to the reverse-blocking type hybrid submodule with the fault blocking capability, a bidirectional conduction-unidirectional blocking switch unit formed by VT7 and VD7 in the conventional CDSM is replaced by a bidirectional conduction-bidirectional blocking switch unit, the positions of 3 devices shown by dotted lines in fig. 1 are adjusted, the number of the devices is not additionally increased, the blocking capability of reverse fault current is improved under the condition that the number of the devices, particularly capacitance devices, is not increased, and the maximum blocking capability of positive and reverse fault currents is 2 UC.
The invention discloses a fault blocking method of a reverse blocking type hybrid submodule with fault blocking capability, which comprises the following steps:
step 1: when a fault occurs, the first switch unit, the second switch unit, the third switch unit, the fourth switch unit and the fifth switch unit are turned off; because the first switch unit, the second switch unit, the third switch unit and the fifth switch unit have the bidirectional conduction-unidirectional blocking function, fault current cannot pass through the insulated gate bipolar transistor after being turned off, but can pass through the freewheeling diode; because the four switch units have the bidirectional conduction-bidirectional blocking function, the fault current cannot pass through the fourth switch unit after the four switch units are switched off.
Step 2: judging the fault current direction: if the fault current flows from the first power supply end, the fault current is a forward fault current, and the step 3 is carried out; if the fault current flows from the second power supply end, the fault current is reverse fault current, and the step 4 is entered.
And step 3: referring to fig. 3, a forward fault current sequentially passes through the freewheeling diode of the first switching unit, the first capacitor, the freewheeling diode of the third switch, the second capacitor, and the freewheeling diode of the fifth switching unit, and flows out from the second power supply terminal, so that the forward fault current charges the first capacitor and the second capacitor connected in series, and the first capacitor and the second capacitor generate a back electromotive force to block the fault current in a charging process.
And 4, step 4: referring to fig. 4, the reverse fault current sequentially passes through the second capacitor of the first clamping diode, the second clamping diode, the first capacitor, and the freewheeling diode of the second switching unit, and flows out from the first power supply end, so that the reverse fault current charges the first capacitor and the second capacitor connected in series, and the first capacitor and the second capacitor generate a back electromotive force to block the fault current in the charging process.
The magnitude of the actually generated back electromotive force is related to the initial value of the system fault current and the equivalent capacitance, and the smaller the equivalent capacitance, the larger the initial value of the fault current is, and the larger the fault blocking voltage is. The fault blocking capability in the invention refers to the maximum generated back electromotive force, and the reverse resistance type mixed submodule with the fault blocking capability can provide 2U at mostCThe back emf of (a) blocks the fault current.

Claims (5)

1. A reverse blocking hybrid submodule having fault blocking capability, comprising: the clamping diode comprises a first half-bridge submodule, a second half-bridge submodule, a first clamping diode and a second clamping diode; the first half-bridge submodule comprises a first switch unit, a second switch unit and a first capacitor; the second half-bridge submodule comprises a third switching unit, a fourth switching unit, a fifth switching unit and a second capacitor; the parameters of the first capacitor and the second capacitor are completely the same, and the voltage reference values of the first capacitor and the second capacitor are both UC；
The first switch unit, the second switch unit, the third switch unit and the fifth switch unit all adopt a structural form that the insulated gate bipolar transistors are connected with the fly-wheel diodes in reverse parallel, so that the bidirectional conduction-unidirectional blocking function is achieved, the conduction direction of the insulated gate bipolar transistors is taken as the forward conduction direction, the conduction direction of the fly-wheel diodes is taken as the reverse conduction direction, and only the forward conduction direction can be turned off; the first switch unit, the second switch unit, the third switch unit and the fifth switch unit are switched on in two directions, and the switching off is carried out in the forward direction;
the fourth switching unit adopts a structural form that two insulated gate bipolar transistors are reversely connected in parallel, so that the fourth switching unit has a bidirectional conduction-bidirectional blocking function; the on state of the fourth switch unit is bidirectional on, and the off state is bidirectional off;
the first switch unit and the second switch unit are connected in series in the forward direction and then connected in parallel with the first capacitor, namely the forward conduction directions of the first switch unit and the second switch unit are consistent, the positive terminal of the first capacitor is connected with the first switch unit, and the negative terminal of the first capacitor is connected with the second switch unit; the forward conduction direction of the third switch unit is consistent with the forward conduction direction of the first switch unit; the third switching unit and the fourth switching unit are connected in series and then are connected in parallel with the first clamping diode, the anode of the first clamping diode is connected with the fourth switching unit, and the cathode of the first clamping diode is connected with the third switching unit; the negative end of the second capacitor is reversely connected with the fifth switch unit in series, the anode of the first clamping diode is connected with the fifth switch unit, and the cathode of the first clamping diode is connected with the positive end of the second capacitor; the positive end of the first capacitor is connected with the negative end of the second capacitor after being connected with the second clamping diode in series, the anode of the second clamping diode is connected with the negative end of the second capacitor, the cathode of the second clamping diode is connected with the positive end of the first capacitor, and the negative end of the first capacitor is connected between the third switch unit and the fourth switch unit, so that the first half-bridge sub-module and the second half-bridge sub-module are connected in series;
the first power supply end is connected between the first switch unit and the second switch unit, and the connection points of the fourth switch unit, the fifth switch unit and the first clamping diode are connected with the second power supply end.
2. The reverse blocking type hybrid submodule with fault blocking capability of claim 1, wherein: can output 0 and U by switching the working modeC、2UCThree operating voltages.
3. The reverse blocking type hybrid submodule with fault blocking capability of claim 2, wherein: the following four working modules are provided:
working mode 1: the first switch unit, the third switch unit and the fifth switch unit are turned off, and the second switch unit and the fourth switch unit are turned on, so that the first capacitor and the second capacitor are both bypassed, and the external output voltage is 0;
the working mode 2 is as follows: the second switch unit, the third switch unit and the fifth switch unit are turned off, and the first switch unit and the fourth switch unit are turned on, so that the first capacitor is connected in series into the circuit, the second capacitor is bypassed, and the external output voltage is UC；
Working mode 3: the first switch unit and the fourth switch unit are disconnected, the second switch unit, the third switch unit and the fifth switch unit are connected, so that the first capacitor is bypassed, the second capacitor is connected in series in the circuit, and the external output voltage is UC；
The working mode 4 is as follows: the second switch unit and the fourth switch unit are turned off, and the first switch unit, the third switch unit and the fifth switch unit are turned on, so that the first capacitor and the second capacitor are connected in series in the circuit, and the external output voltage is 2UC。
4. The reverse blocking type hybrid submodule with fault blocking capability of claim 1, wherein: can provide 2UCThe back emf of (a) blocks the fault current.
5. A fault blocking method using the reverse blocking type hybrid submodule with fault blocking capability of claim 1, comprising the steps of:
step 1: when a fault occurs, the first switch unit, the second switch unit, the third switch unit, the fourth switch unit and the fifth switch unit are turned off;
step 2: judging the fault current direction: if the fault current flows from the first power supply end, the fault current is a forward fault current, and the step 3 is carried out; if the fault current flows from the second power supply end, the fault current is reverse fault current, and the step 4 is carried out;
and step 3: forward fault current sequentially passes through the freewheeling diode of the first switch unit, the first capacitor, the freewheeling diode of the third switch, the second capacitor and the freewheeling diode of the fifth switch unit and flows out of the second power supply end, so that the forward fault current charges the first capacitor and the second capacitor which are connected in series, and the first capacitor and the second capacitor generate back electromotive force to block the fault current in the charging process;
and 4, step 4: the reverse fault current sequentially passes through the first clamping diode, the second capacitor, the second clamping diode, the first capacitor and the freewheeling diode of the second switch unit and flows out of the first power supply end, so that the reverse fault current charges the first capacitor and the second capacitor which are connected in series, and the first capacitor and the second capacitor generate counter electromotive force to block the fault current in the charging process.
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CN110994974B (en) * 2019-11-25 2020-11-20 上海交通大学 Low-loss modular multi-level direct current-direct current converter and submodule thereof
CN110890743B (en) * 2019-11-25 2020-11-20 上海交通大学 Low-loss modular multilevel DC transformer with fault blocking capability
CN112039360A (en) * 2020-08-12 2020-12-04 华北电力大学（保定） MMC submodule with fault current blocking and self-voltage-sharing capabilities
CN113489359B (en) * 2021-06-24 2023-11-28 昆明理工大学 Submodule topology with direct-current fault clearing capability

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* Cited by examiner, † Cited by third party
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CN102611096A (en) * 2012-03-13 2012-07-25 浙江大学 Bipolar direct current power transmission system with direct current failure self-elimination capacity
CN104038090B (en) * 2014-06-23 2017-01-04 威凡智能电气高科技有限公司 A kind of based on the antiparallel T-shaped multi-level inverter circuit of reverse blocking IGBT
CN204068699U (en) * 2014-09-11 2014-12-31 华南理工大学 A kind of MMC submodule with direct-current short circuit fault self-cleaning ability
CN104638615A (en) * 2015-02-16 2015-05-20 天津大学 Modular multilevel converter with direct-current fault isolation function and submodule thereof
US9806601B2 (en) * 2015-03-27 2017-10-31 Futurewei Technologies, Inc. Boost converter and method
CN204835976U (en) * 2015-07-22 2015-12-02 清华大学 Take three many level of level modularization converter module circuit of short -circuit protection
CN206602450U (en) * 2016-11-10 2017-10-31 中国石油大学(华东) A kind of MMC submodules with direct-current short circuit electric current self-cleaning ability
CN107370406A (en) * 2017-08-29 2017-11-21 华北电力大学（保定） The level MMC submodules of failure self-cleaning three and the transverter with the submodule
CN107947608B (en) * 2017-12-06 2019-11-12 上海海事大学 A kind of AC/DC current transformer with automatic equalization DC output voltage function
CN108900103A (en) * 2018-08-23 2018-11-27 中国能源建设集团广东省电力设计研究院有限公司 The converter power module and inverter for having DC Line Fault self-cleaning ability

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