CN112865506A - MMC dual-sub-module with bidirectional fault current removal capability - Google Patents

MMC dual-sub-module with bidirectional fault current removal capability Download PDF

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CN112865506A
CN112865506A CN202110283822.5A CN202110283822A CN112865506A CN 112865506 A CN112865506 A CN 112865506A CN 202110283822 A CN202110283822 A CN 202110283822A CN 112865506 A CN112865506 A CN 112865506A
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module
sub
mmc
hbsm
fault current
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刘晔
王浩
史卓卿
郝颖琪
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Xian Jiaotong University
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • 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
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
    • 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
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/483—Converters with outputs that each can have more than two voltages levels
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)

Abstract

MMC dual-sub-module with bidirectional fault current removal capability comprises two half-bridge sub-modules HBSM with same structure1And HBSM2A connection circuit and a reverse blocking circuit, wherein the connection circuit is connected to the HBSM1And HBSM2To (c) to (d); the reverse blocking circuit and HBSM1And HBSM2And the negative electrode of the parallel connection is connected with the positive electrode of the dual-sub module, and the positive electrode of the parallel connection is connected with the negative electrode of the dual-sub module, so that the effect of inhibiting and absorbing reverse fault large current is achieved.

Description

MMC dual-sub-module with bidirectional fault current removal capability
Technical Field
The invention belongs to the technical field of new energy, is applied to a flexible direct current power transmission system, and particularly relates to an MMC dual-sub-module with bidirectional fault current removal capability.
Background
With the exhaustion of traditional resources, the renewable energy market is further expanded, which also puts higher demands on the transmission level of the power system. Compared with a high-voltage alternating-current transmission technology, the high-voltage direct-current transmission technology has more advantages in stability and energy loss, wherein the Modular Multilevel Converter (MMC) technology is widely applied to the academic and engineering fields due to the characteristics of integrated modularization, high transmission efficiency, flexible control and the like. The MMC is suitable for high-power occasions, and due to the fact that a modular design concept is adopted, the capability of a single sub-module for resisting the level faults of the current converter is insufficient, and therefore the capability of the current converter for responding to the faults to be faced is required to be enhanced when the current converter is designed.
Disclosure of Invention
In order to overcome the defects of the prior art, further inhibit the amplitude of the fault current and save the power as much as possible, and to address the situation that the fault clearing capability of a typical MMC submodule is insufficient, the invention aims to provide an MMC submodule with bidirectional fault current removal capability, namely a Reverse Blocked submodule (RBDSM), which can not only improve the capability of the MMC on the submodule to cope with the dc side fault, but also has certain advantages in reducing the device cost.
In order to achieve the purpose, the invention adopts the technical scheme that:
MMC dual-sub-module with bidirectional fault current removal capability comprises two half-bridge sub-modules HBSM with same structure1And HBSM2A connection circuit and a reverse blocking circuit, wherein the connection circuit is connected to the HBSM1And HBSM2To (c) to (d); the reverse blocking circuit and HBSM1And HBSM2And the negative electrode of the parallel connection is connected with the positive electrode of the dual-sub module, and the positive electrode of the parallel connection is connected with the negative electrode of the dual-sub module, so that the effect of inhibiting and absorbing reverse fault large current is achieved.
The HBSM1The full-control power switch tube comprises full-control power switch tubes T1 and T2, diodes D1 and D2 and a capacitor C1, wherein the source of T1 is connected with the anode of D1, the cathode of D2, the drain of T2 and the anode of the bimodule, the drain of T1 is connected with the cathode of D1 and the anode of C1, and the cathode of C1 is connected with the source of T2 and the anode of D2;
the HBSM2The full-control power switch comprises fully-control power switch tubes T3 and T4, diodes D3 and D4 and a capacitor C2, wherein a source of T3 is connected with an anode of D3, a cathode of D4 and a drain of T4, a drain of T3 is connected with a cathode of D3 and an anode of C2, and a cathode of C2 is connected with a source of T4, an anode of D4 and a cathode of a double-sub module.
The connecting circuit consists of a fully-controlled power switch tube T5 and a diode D5, wherein the source of T5 is connected with the anode of D5 and the anode of D2, the drain of T5 is connected with the cathode of D5 and the cathode of D4, and in normal operation, the conduction direction of T5 is opposite to the conduction directions of T1, T2, T3 and T4, and when the HBSM1 and the HBSM2 are connected, the connecting circuit plays a role in preventing fault current from flowing through HBSM1 and HBSM 2.
The fully-controlled power switch tube is an insulated gate bipolar transistor.
The reverse blocking circuit is composed of an absorption capacitor C3 and a diode D6, the anode of the MMC double-sub module is connected with the cathode of D6, the anode is connected with one end of C3, and the other end of C3 is connected with the cathode of the MMC double-sub module.
In normal operation, HBSM1And HBSM2Control and modulation strategies are employed, respectively, which use the MMC circuit modulation strategy of a conventional HBSM module.
When the MMC has direct current side fault, T1, T2, T3, T4 and T5 stop working at the first time and keep a locking state so as to protect the power supply equipment; when fault current ismWhen flowing from the positive pole of the dual sub-module, C1 and C2 are used to suppress the rapid increase of fault current; when a fault current flows from the negative pole of the bimodule, the fault current can only pass through the reverse blocking circuit, is blocked by the C3 and quickly suppresses the increase of the large current.
Compared with the prior art, the invention has the beneficial effects that:
the improved dual sub-module of the invention inherits the characteristics of a typical dual sub-module, and two HBSMs in the module can be independently controlled and are consistent with a common HBSM; the added IGBT element only needs to change a control signal under the condition of starting or stopping for maintenance, and an additional control algorithm is not needed; the additional reverse blocking circuit can inhibit the increase of current in time when fault heavy current reversely flows, blocks the fault current, and has important significance for reliable and safe operation of the high-voltage direct-current power transmission system.
Drawings
FIG. 1 is a diagram of the topology of the dual sub-module of the present invention.
FIG. 2 is a schematic diagram of the fault type of the MMC DC side system of the present invention.
FIG. 3 is a schematic diagram of a current path when a DC side bipolar of the MMC of the present invention is shorted.
FIG. 4 shows the equivalent circuit (i) of the MMC of the present invention in case of failuresm>0)。
FIG. 5 shows the equivalent circuit (i) of the MMC of the present invention in case of failuresm<0)。
FIG. 6 is a schematic diagram of a two-terminal MMC system of the present invention.
Fig. 7 is an upper arm voltage waveform.
Fig. 8 is a three-phase modulated wave waveform.
Fig. 9 shows a dc bus voltage current waveform.
Fig. 10 is a three-phase alternating current voltage current waveform.
FIG. 11 is a dual sub-module capacitor voltage waveform.
Detailed Description
The embodiments of the present invention will be described in detail below with reference to the drawings and examples.
The invention relates to an MMC (modular multilevel converter) dual-Sub-module with bidirectional fault current removal capacity, namely a Reverse Blocked dual-Sub-module (RBDSM), which comprises a half-bridge Sub-module HBSM (basic block Sub-module) with the same structure as shown in figure 11And HBSM2And a connecting circuit and a reverse blocking circuit. The connection circuit is connected to HBSM1And HBSM2The negative pole of the reverse blocking circuit is connected with the positive pole of the dual sub-module, the positive pole is connected with the negative pole of the dual sub-module, and the reverse blocking circuit is connected with the HBSM in the whole view1And HBSM2And the parallel connection can timely restrain the current increase when the fault large current reversely flows.
The invention inherits the characteristics of a typical dual sub-module, can separately adopt control and modulation strategies, is consistent with the common HBSM, and the modulation strategy of the MMC circuit of the traditional HBSM module is also suitable for the MMC circuit using the RBDSM module.
In an embodiment of the invention, HBSM1The full-control power switch tube comprises full-control power switch tubes T1 and T2, diodes D1 and D2 and a capacitor C1, wherein the source of T1 is connected with the anode of D1, the cathode of D2, the drain of T2 and the anode of a double-sub module, the drain of T1 is connected with the cathode of D1 and the anode of C1, and the cathode of C1 is connected with the source of T2 and the anode of D2.
HBSM2The full-control power switch comprises fully-control power switch tubes T3 and T4, diodes D3 and D4 and a capacitor C2, wherein a source of T3 is connected with an anode of D3, a cathode of D4 and a drain of T4, a drain of T3 is connected with a cathode of D3 and an anode of C2, and a cathode of C2 is connected with a source of T4, an anode of D4 and a cathode of a double-sub module.
The connection circuit is composed of a fully-controlled power switch tube T5 and a diode D5, the source of T5 is connected with the anode of D5 and the anode of D2, the drain of T5 is connected with the cathode of D5 and the cathode of D4, the conduction direction of T5 is opposite to the conduction directions of T1, T2, T3 and T4 during normal operation, and the connection circuit plays a role in preventing fault current from flowing through HBSM1 and HBSM2 while connecting HBSM1 and HBSM 2.
In the embodiment of the invention, all the fully-controlled power switch tubes are all insulated gate bipolar transistors.
The reverse blocking circuit is composed of an absorption capacitor C3 and a diode D6, wherein the negative electrode of D6 is connected with the positive electrode of the MMC double-sub module, the positive electrode of the D6 is connected with one end of C3, and the other end of C3 is connected with the negative electrode of the MMC double-sub module.
Referring to table 1, there are 6 operation modes of the dual sub-module of the present invention.
TABLE 1 modes of operation
Figure BDA0002979591410000041
The ability of the dual submodule to suppress and cut off fault current is analyzed below by taking bipolar short circuit fault on the dc side as an example. The MMC-HVDC system mainly comprises a direct current power system, a converter station and an alternating current power system, fault protection of the system is divided into direct current side fault protection, alternating current side fault protection and converter fault protection, and in the direct current side system fault protection, the fault protection can be divided into three types, namely unipolar short-circuit fault of a direct current bus, bipolar short-circuit fault of the direct current bus and direct current bus disconnection fault according to the expression form of the fault protection. The bipolar short-circuit fault is the most serious fault, and the short circuit of the positive electrode and the negative electrode of the direct current bus can generate large fault current and seriously threaten the safety of power equipment devices and a converter system.
Referring to fig. 2 and 3, in the event of a short-circuit fault of the dc-side positive and negative dc buses, there is a fixed fault current path between the a and B phases. Fault current ismWhen the current is larger than zero, the current flows through the circuits of the B-phase lower bridge arm, the short-circuit point and the A-phase upper bridge arm in sequence; fault current ismWhen the current is less than zero, the current passes through the circuits of the phase A upper bridge arm, the short-circuit point and the phase B lower bridge arm in sequence. According to the three-phase MMC structure, the topology of the dual sub-modules and the basic circuit principle, an equivalent circuit is obtained through analysis and is shown in the figures 4 and 5. The circuit is analyzed to obtain the mechanism of fault clearing of the present invention.
When the fault current is larger than zero, according to the circuit principle and the characteristics of the MMC circuit, the following formula is established:
Figure BDA0002979591410000051
in the formula: u shapedcIs bus voltage/kV; n is a radical ofsmIs RBDSM number; u shapecNIs the reference voltage/kV of the capacitor C1; m is an MMC modulation coefficient and generally does not exceed 1; u shapepPhase voltage amplitude/kV; u shapeLIs the amplitude of the line voltage/kV.
When the fault current is greater than 0, referring to mode 5 of table 1, when the MMC has a dc-side fault, T1, T2, T3, T4, T5 all stop working at the first time and maintain a locked state, thereby protecting power electronic devices such as power supply equipment. Whereas in fig. 4, the fault current ismFlows from the positive electrode of the bimodule, and the internal current of the bimodule flows from the positive electrodeTo the negative pole, the dc fault current passes through two capacitors (C1 and C2) and three diodes (D1, D3, and D5) in each submodule. According to kirchhoff's voltage law and the specific circuit structure of MMC, the following conditions need to be satisfied:
Figure BDA0002979591410000061
combining the three equations of equation (2) and deriving, the total voltage of diodes D1, D3, and D5 can be expressed as:
Figure BDA0002979591410000062
obviously, formula (3) shows that the three diodes are subjected to reverse bias voltage, and due to the unidirectional conduction characteristic of the diodes, the diodes cannot conduct, so that the fault current is effectively suppressed and cut off, the influence caused by the fault is quickly eliminated, and the capacitors C1 and C2 can suppress the quick increase of the fault current.
When the fault current is less than 0, referring to mode 6 of table 1, the fault current flows from the negative electrode of the bimodule and can only flow through the reverse blocking circuit, and at this time, the condition is satisfied:
Figure BDA0002979591410000063
solving to obtain:
Figure BDA0002979591410000064
according to the formula, when the absorption capacitor C3 is charged to a certain level, the voltage applied to the diode D6 becomes a negative voltage, thereby rapidly suppressing the current increase.
Through the derivation, no matter fault current flows into the double sub-modules from the positive electrode or the negative electrode, after all the fully-controlled power switch tubes are locked, the RBDSM can enable the voltage applied to the diode to be smaller than 0, so that the fault current can be quickly cut off by means of the unidirectional conduction characteristic of the diode of the power device, and then the fault can be cleared. In addition, the IGBT element added in the invention only needs to change the control signal under the condition of starting or stopping for maintenance, and an additional control algorithm is not needed.
Fig. 6 shows a simulation model for a double-ended MMC consisting of two MMCs (the RBDSM of the present invention is an MMC submodule, each phase of which is formed by connecting multiple submodules in series), two ac power systems, two start-up circuits, and a dc bus. The two alternating current sides of the MMC are power supply ends, and the power is transmitted between the two alternating current power systems by controlling active power and reactive power of the current converter in the model.
When the system is in a steady state, as shown in fig. 7 and fig. 8, the RBDSM-MMC has good steady-state performance. The bridge arm voltage on the phase A is basically maintained to be about 2 kV-18 kV, the bridge arm voltage is kept relatively stable, the waveform of a three-phase modulation wave is close to a sine wave, the amplitude is about 0.4, and the modulation ratio is expected to be 0.8, so that the dual-sub module can meet the normal operation requirement.
In the pre-charging stage, as shown in fig. 9, the starting circuit on the ac side of the MMC is in a disconnected state, and the current-limiting resistor starts to operate to limit the amplitude of the starting current, so that all IGBTs cannot be effectively controlled because the power supply of the driving circuit is not charged yet; when the voltage of the direct current bus reaches 15kV in 0.15 second, the switch of the starting circuit 1 is closed, and the MMC1 starts to be in a normal running state; at 0.3 seconds, the switch of the start-up circuit 2 is closed and the MMC2 starts working normally. And then, the voltage of the direct current bus reaches the preset 20kV (rated voltage of the direct current bus) in about 0.4 second, and the whole converter system stably operates.
The performance of the RBDSM under the dc-side fault condition is shown in fig. 10 and 11, when the double-ended MMC system operates for 0.8 seconds, a bipolar short-circuit fault occurs on the dc-side, the dc bus voltage drops to 0 instantaneously, and the dc bus current jumps to 3 kA. Then, the control system quickly disconnects all power tubes, and due to the fault self-clearing capability of the dual sub-module, the amplitude of the bus current is limited and quickly drops to 0 within 0.82 second, so that the improved RBDSM is verified to play a role in protecting the system in case of fault. Meanwhile, a three-phase alternating current power supply measured by alternating current is influenced, when a 0.8-second fault just occurs, three-phase voltage is distorted to a certain degree, the three-phase current is seriously distorted, the sine wave is recovered to 0.825 seconds of alternating current voltage after the three-phase voltage is processed by a control system, the alternating current is reduced to 0, and finally the MMC system successfully clears the serious short-circuit fault current.
The performance of the dual sub-module in the whole transient process is shown in fig. 11, the capacitors C1 and C2 in the RBDSM, which are responsible for the output voltage, reach 0.71UcN at the end of the system uncontrollable pre-charging phase, reach UcN at 0.25 seconds, and the fluctuation of the capacitor voltage is very small. After the 0.8 second fault occurred, the voltages of C1 and C2 remained unchanged due to the shut-off of T5. Meanwhile, the capacitance (C3) of the reverse blocking circuit absorbs the impact large current for 0.82 second to reach 1.05kv and keeps stable. It can be seen that the reverse blocking circuit of the RBDSM plays an important role in cutting off dc fault currents.
The charging current amplitude is limited by a starting circuit of the system in an uncontrolled pre-charging stage of starting the system, so that the impact of large current on power electronic devices is reduced; entering a steady state, and controlling HBSM in RBDSM independently without influencing normal operation; after the fault occurs, the system quickly locks all IGBTs, the RBDSM plays a role in restraining fault current, the fault current is limited, and the MMC system successfully clears the fault.
In summary, the present invention provides an improved dual sub-module structure, RBDSM, for solving the problem that the half-bridge sub-module cannot suppress the fault current and the full-bridge sub-module has higher cost. On the basis of keeping the original modulation and control strategies of the half-bridge submodule unchanged, the bi-directional fault current of the submodule can be effectively inhibited, the submodule can use power devices with lower withstand voltage requirements and fewer power devices, and the construction cost of the converter is reduced.

Claims (7)

1. MMC dual-sub-module with bidirectional fault current removal capability is characterized by comprising two half-bridge sub-modules HBSM with same structure1And HBSM2A connection circuit and a reverse blocking circuit, wherein the connection circuit is connected to the HBSM1And HBSM2To (c) to (d); the reverse blocking circuit and HBSM1And HBSM2And the negative electrode of the parallel connection is connected with the positive electrode of the dual-sub module, and the positive electrode of the parallel connection is connected with the negative electrode of the dual-sub module, so that the effect of inhibiting and absorbing reverse fault large current is achieved.
2. The MMC dual-sub-module with bidirectional fault current removal capability of claim 1, wherein the HBSM1The full-control power switch tube comprises full-control power switch tubes T1 and T2, diodes D1 and D2 and a capacitor C1, wherein the source of T1 is connected with the anode of D1, the cathode of D2, the drain of T2 and the anode of the bimodule, the drain of T1 is connected with the cathode of D1 and the anode of C1, and the cathode of C1 is connected with the source of T2 and the anode of D2;
the HBSM2The full-control power switch comprises fully-control power switch tubes T3 and T4, diodes D3 and D4 and a capacitor C2, wherein a source of T3 is connected with an anode of D3, a cathode of D4 and a drain of T4, a drain of T3 is connected with a cathode of D3 and an anode of C2, and a cathode of C2 is connected with a source of T4, an anode of D4 and a cathode of a double-sub module.
3. The MMC dual-sub-module with bidirectional fault current cutting capability of claim 2, wherein the connection circuit is composed of a fully-controlled power switch T5 and a diode D5, a source of T5 is connected with an anode of D5 and an anode of D2, a drain of T5 is connected with a cathode of D5 and a cathode of D4, and in normal operation, the conduction direction of T5 is opposite to the conduction directions of T1, T2, T3 and T4, and when HBSM1 and HBSM2 are connected, the function of preventing fault current from flowing through HBSM1 and HBSM2 is achieved.
4. The MMC double sub-module with bidirectional fault current removal capability of claim 3, wherein the fully controlled power switch is an insulated gate bipolar transistor.
5. According to claim1 the MMC dual sub-module with bidirectional fault current removal capability is characterized in that in normal operation, HBSM1And HBSM2Control and modulation strategies are employed, respectively, which use the MMC circuit modulation strategy of a conventional HBSM module.
6. The MMC double sub-module with bidirectional fault current cutting capability of claim 1, 2, 3, 4 or 5, wherein said reverse blocking circuit is composed of a absorption capacitor C3 and a diode D6, the cathode of D6 is connected to the anode of MMC double sub-module, the anode is connected to one end of C3, and the other end of C3 is connected to the cathode of MMC double sub-module.
7. The MMC dual sub-module with bidirectional fault current removal capability of claim 6, wherein when the MMC has a DC side fault, T1, T2, T3, T4, T5 stop working for the first time and maintain a locked state to protect power devices; when fault current ismWhen flowing from the positive pole of the dual sub-module, C1 and C2 are used to suppress the rapid increase of fault current; when a fault current flows from the negative pole of the bimodule, the fault current can only pass through the reverse blocking circuit, is blocked by the C3 and quickly suppresses the increase of the large current.
CN202110283822.5A 2021-03-17 2021-03-17 MMC dual-sub-module with bidirectional fault current removal capability Pending CN112865506A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113992037A (en) * 2021-12-30 2022-01-28 华北电力大学（保定） Bidirectional self-blocking plug module topological structure and fault ride-through method thereof

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CN108306318A (en) * 2018-01-11 2018-07-20 北京交通大学 Symmetrical energy-storage system based on Modular multilevel converter
CN110429843A (en) * 2019-07-30 2019-11-08 西安交通大学 A kind of MMC Shuangzi module topology with DC side failure self-cleaning ability
CN112039361A (en) * 2020-09-04 2020-12-04 华北电力大学（保定） MMC sub-module and MMC latch-free low-voltage fault ride-through method applying same

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108306318A (en) * 2018-01-11 2018-07-20 北京交通大学 Symmetrical energy-storage system based on Modular multilevel converter
CN110429843A (en) * 2019-07-30 2019-11-08 西安交通大学 A kind of MMC Shuangzi module topology with DC side failure self-cleaning ability
CN112039361A (en) * 2020-09-04 2020-12-04 华北电力大学（保定） MMC sub-module and MMC latch-free low-voltage fault ride-through method applying same

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113992037A (en) * 2021-12-30 2022-01-28 华北电力大学（保定） Bidirectional self-blocking plug module topological structure and fault ride-through method thereof

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Application publication date: 20210528