Bridge arm sub-module, converter valve module, converter valve equipment and power distribution system

Abstract

The invention relates to a bridge arm sub-module, a converter valve module, converter valve equipment and a power distribution system. The bridge arm sub-module comprises a plurality of integrated gate commutated thyristor devices which are connected in series, energy-taking power supplies corresponding to the integrated gate commutated thyristor devices, an anti-parallel unit, a voltage-sharing module and a driving unit, the anti-parallel unit and the voltage-sharing module are connected in parallel to the two sides of the integrated gate commutated thyristor device; the driving unit is connected with the integrated gate commutated thyristor device, and the energy-taking power supply is connected with the driving unit; and the energy-taking power supply is connected with the voltage-sharing module and is used for obtaining electric energy from the voltage-sharing module and supplying power to the driving unit. The bridge arm submodule provided by the invention does not need to be provided with a bypass switch, the long-term reliable short-circuit through-current capability after the IGCT device fails is fully utilized, and the stable operation of a power distribution system is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of high-voltage power grids, and particularly to a bridge arm sub-module, a converter valve module, a converter valve device, and a power distribution system. Background Art

[0002] In an existing series module of integrated gate-commutated thyristor (IGCT) devices, when a fault occurs in a unit where an IGCT device is located, the control unit needs to quickly detect the location of the faulty unit and send a closing signal to drive the bypass switch to change its on / off state, so as to avoid interruption of system operation.

[0003] The existing series module of IGCT devices has high cost, large volume, and does not fully utilize the characteristics of IGCTs. Summary of the Invention

[0004] To solve the above technical problems, it is necessary to provide a bridge arm sub-module, a converter valve module, a converter valve device, and a power distribution system that can effectively reduce the cost of the series module of IGCT devices and give full play to the characteristics of IGCTs. The specific solutions are as follows:

[0005] In a first aspect, the present embodiment provides a bridge arm sub-module, including: a plurality of series-connected integrated gate-commutated thyristor devices and an energy extraction power supply, an anti-parallel unit, a voltage equalizing module, and a driving unit corresponding to each integrated gate-commutated thyristor device;

[0006] Both the anti-parallel unit and the voltage equalizing module are connected in parallel on both sides of the integrated gate-commutated thyristor device;

[0007] The driving unit is connected to the integrated gate-commutated thyristor device, and the energy extraction power supply is connected to the driving unit;

[0008] The energy extraction power supply is connected to the voltage equalizing module, and is used to obtain electrical energy from the voltage equalizing module and supply power to the driving unit.

[0009] In one embodiment, the number of integrated gate-commutated thyristors is greater than or equal to a preset redundancy number threshold, where the preset redundancy number threshold is greater than a preset working number threshold, and the preset working number threshold is the minimum number of integrated gate-commutated thyristor devices when the bridge arm sub-module operates normally.

[0010] In one embodiment, the voltage equalizing module includes a dynamic voltage equalizing unit and a static voltage equalizing unit;

[0011] The dynamic voltage equalizing unit and the static voltage equalizing unit are respectively connected in parallel on both sides of the integrated gate-commutated thyristor device.

[0012] In one embodiment, the dynamic voltage equalizing unit includes an energy-taking capacitor, a rectifying diode, and a first voltage-dividing resistor;

[0013] One end of the energy-taking capacitor is connected to the cathode of the integrated gate-commutated thyristor, the other end of the energy-taking capacitor is connected to the cathode of the rectifying diode, and the anode of the rectifying diode is connected to the anode of the integrated gate-commutated thyristor;

[0014] The first voltage-dividing resistor is connected in parallel on both sides of the rectifying diode;

[0015] The energy-taking power supply is connected in parallel on both sides of the energy-taking capacitor.

[0016] In one embodiment, the static voltage equalizing unit includes a second voltage-dividing resistor;

[0017] The second voltage-dividing resistor is connected in parallel on both sides of the integrated gate-commutated thyristor.

[0018] In one embodiment, the anti-parallel unit includes a diode;

[0019] The cathode of the diode is connected to the anode of the integrated gate-commutated thyristor, and the anode of the diode is connected to the cathode of the integrated gate-commutated thyristor.

[0020] In a second aspect, the present embodiment provides a commutation valve module, including: a switched-capacitor bridge arm, an integrated gate-commutated thyristor device series-connected H-bridge arm, and an AC connection reactance connected in sequence;

[0021] The switched-capacitor bridge arm includes a plurality of half-bridge sub-modules connected in cascade, wherein the half-bridge sub-module includes an insulated gate bipolar transistor; the switched-capacitor bridge arm is used to access a DC signal;

[0022] The integrated gate-commutated thyristor device series-connected H-bridge arm includes four bridge arm sub-modules described in the first aspect;

[0023] The output end of the integrated gate-commutated thyristor device series-connected H-bridge arm outputs an AC signal through the AC connection reactance.

[0024] In a third aspect, the present embodiment provides a commutation valve device, including: a DC filter, a commutation valve module, and a commutation transformer connected in sequence;

[0025] The DC filter is used to access a DC signal and perform filtering processing on the DC signal;

[0026] The commutation valve module includes the commutation valve module described in the second aspect, and the commutation valve module is used to convert the DC signal into an intermediate AC signal;

[0027] The commutation transformer is used to perform voltage transformation processing on the intermediate AC signal output by the commutation valve module to output a target AC signal.

[0028] In one embodiment, the commutation valve module includes a first commutation valve module, a second commutation valve module, and a third commutation valve module;

[0029] The switching capacitor bridge arms of the first commutation valve module, the second commutation valve module, and the third commutation valve module are connected in cascade;

[0030] The first commutation valve module is used to output a first-phase intermediate AC signal according to the DC signal;

[0031] The second commutation valve module is used to output a second-phase intermediate AC signal according to the DC signal;

[0032] The third commutation valve module is used to output a third-phase intermediate AC signal according to the DC signal.

[0033] In a fourth aspect, this embodiment provides a power distribution system, including the commutation valve device described in the third aspect.

[0034] In summary, this application provides a bridge arm sub-module, a commutation valve module, a commutation valve device, and a power distribution system, including: a plurality of series-connected integrated gate-commutated thyristor devices and an energy extraction power supply, an anti-parallel unit, a voltage equalization module, and a driving unit corresponding to each integrated gate-commutated thyristor device; the anti-parallel unit and the voltage equalization module are both connected in parallel on both sides of the integrated gate-commutated thyristor device; the driving unit is connected to the integrated gate-commutated thyristor device, and the energy extraction power supply is connected to the driving unit; the energy extraction power supply is connected to the voltage equalization module, is used to obtain electric energy from the voltage equalization module, and supply power to the driving unit. The bridge arm sub-module provided by this application does not need to set a bypass switch, makes full use of the long-term reliable short-circuit current-carrying capacity after the failure of the IGCT device, and ensures the stable operation of the power distribution system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0036] Figure 1 It is a module schematic diagram of the commutation valve topology structure provided for one embodiment;

[0037] Figure 2Module schematic diagram of a commutation valve structure provided for an embodiment;

[0038] Figure 3 Circuit schematic diagram of a first commutation valve provided for an embodiment;

[0039] Figure 4 Circuit schematic diagram of three cascaded commutation valves provided for an embodiment;

[0040] Figure 5 Circuit schematic diagram of a commutation transformer provided for an embodiment;

[0041] Figure 6 Module schematic diagram of a bridge arm sub-module provided for an embodiment;

[0042] Figure 7 Turn-on breakdown curve diagram of an IGCT device provided for an embodiment;

[0043] Figure 8 Circuit schematic diagram of a bridge arm sub-module provided for an embodiment.

[0044] Explanation of reference numerals:

[0045] Commutation valve module - 110; First commutation valve module - 111; Second commutation valve module - 112; Third commutation valve module - 113; DC filter - 120; Commutation transformer - 130; Switching capacitor bridge arm - 210; IGCT device series H-bridge arm - 220; AC connection reactance - 230. Detailed implementation manners

[0046] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the specification of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0048] It will be understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0049] It will be understood that for "connection" in the following embodiments, if there is transmission of electrical signals or data between the connected circuits, modules, units, etc., it should be understood as "electrical connection", "communication connection", etc.

[0050] It will be understood that "at least one" means one or more, and "a plurality" means two or more. "At least a part of an element" means a part or all of the element.

[0051] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprises / comprising", "has / including", etc. specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the related listed items.

[0052] In the related art, an Integrated Gate-Commutated Thyristor (IGCT for short), also known as a Gate-Commutated Thyristor (GCT for short), combines the characteristics of a Gate-Turn-Off Thyristor (GTO for short) and an Insulate-Gate Bipolar Transistor (IGBT for short). It has the advantages of fast switching speed, low loss, and high blocking voltage. Due to the advantages of high blocking voltage and stable short circuit after failure of IGCT devices, series-connected IGCT devices can support high-voltage systems.

[0053] There are rich new energy resources such as wind energy and solar energy in sandy, desert and barren areas, which is conducive to large-scale centralized development. However, there are many problems, such as high uncertainty of power sources, high construction cost of thermal power, low proportion of synchronous units, and weak local power grids. At present, the adopted AC collection method faces challenges such as voltage instability, transient overvoltage, and broadband oscillation. By configuring a large number of synchronous support devices such as thermal power units, synchronous condensers, and network-forming energy storage, the cost is expensive, and the synchronous stability problem brought by the first principle of AC collection cannot be eradicated.

[0054] Photovoltaic medium-voltage DC power generation has no problems such as frequency and phase synchronization, and can fundamentally solve the problem of AC power angle stability. Moreover, through the all-DC power transmission method of DC collection and DC transmission, the amount of cables and the power conversion links can be reduced. After mass production, the transmission efficiency and equipment manufacturing cost will be greatly reduced, which is an effective solution for the power transmission of large-scale new energy bases in the future.

[0055] In the field of photovoltaic medium-voltage DC power generation, the converter valve topology can use a Modular Communicated Converter (MCC for short). As Figure 1 shown, as a new type of DC / AC voltage source converter, the MCC, that is, the converter valve device includes a converter valve module 110, a DC filter 120, and a converter transformer 130. Among them, the converter valve module 110 includes three converter valve modules, namely the first converter valve module 111, the second converter valve module 112, and the third converter valve module 113. As Figure 2 shown, each converter valve includes a switched capacitor bridge arm 210, an IGCT device series-type H-bridge arm 220, and an AC connection reactance 230.

[0056] Taking the circuit topology of the first converter valve module 111 as an example for illustration, as Figure 3 shown, the switched capacitor bridge arm 210 includes a plurality of cascaded half-bridge sub-modules, which are respectively half-bridge sub-modules , and . In this embodiment, the half-bridge sub-module includes IGBT devices. As Figure 4As shown, the half-bridge sub-modules of the switched capacitor bridge arm 210 between different converter valves are cascaded with each other. After the three switched capacitor bridge arms 210 on the DC side are cascaded, a higher-level DC voltage can be generated. The DC ports of the converter valves are connected in series through the DC filter 120 to form the total DC voltage. In the actual application process, the cascaded structure of the three converter valve modules can be decoupled and controlled, and the three converter valve modules operate with a 120° phase difference to achieve three-phase output. That is, the first converter valve module 111 is used to output the first-phase intermediate AC signal according to the DC signal, the second converter valve module 112 is used to output the second-phase intermediate AC signal according to the DC signal, and the third converter valve module 113 is used to output the third-phase intermediate AC signal according to the DC signal.

[0057] The IGCT device series-connected H-bridge arm 220 includes four bridge arm sub-modules, and each bridge arm sub-module is composed of a plurality of IGCT devices connected in series, such as Figure 3 shown, the bridge arm sub-module is composed of IGCT devices connected in series, and the IGCT devices to constitute a bridge arm sub-module, and the IGCT devices to constitute another bridge arm sub-module. Similarly, the IGCT devices to constitute a bridge arm sub-module, and the IGCT devices to constitute another bridge arm sub-module. The bridge arm sub-module composed of IGCT devices connected in series has the advantages of high blocking voltage, large power capacity, fast turn-on speed, low on-state loss, large surge current, easy series connection, high reliability, strong anti-interference ability, stable short circuit after failure, and good explosion-proof characteristics.

[0058] In the converter valve, the switched capacitor bridge arm 210 cascaded by the half-bridge sub-modules generates a half-wave sine wave, and then the IGCT device series-connected H-bridge arm 220 flips at the voltage zero-crossing point to achieve AC output, and finally is connected to the AC grid through the converter transformer 130. The circuit structure of the converter transformer 130 is as Figure 5 shown, where and are the AC connection reactances 230 of the first converter valve module 111, and are the AC connection reactances 230 of the second converter valve module 112, and are the AC connection reactances 230 of the third converter valve module 113. The converter transformer 130 is transformer T1, and the resistor and the switches , constitute the output unit of the converter transformer 130 for connecting to the AC grid.

[0059] As Figure 6 shown, a bridge arm sub-module is provided, including: a plurality of series-connected integrated gate-commutated thyristor (IGCT) devices, and an energy extraction power supply, an anti-parallel unit, a voltage equalizing module, and a driving unit corresponding to each integrated gate-commutated thyristor device.

[0060] The anti-parallel unit and the voltage equalizing module are both connected in parallel on both sides of the integrated gate-commutated thyristor device. The driving unit is connected to the integrated gate-commutated thyristor device, and the energy extraction power supply is connected to the driving unit. The energy extraction power supply is connected to the voltage equalizing module, and is used to obtain electrical energy from the voltage equalizing module and supply power to the driving unit.

[0061] In this embodiment, the number of IGCT devices and related circuits can be n, where n is a positive integer. The number of IGCT devices is associated with the voltage level of the commutation valve device to which the bridge arm sub-module is applied. The higher the voltage level, the more IGCT devices.

[0062] In the actual application process, each IGCT device is configured with a corresponding voltage equalizing module and a driving unit, and the driving unit can drive the IGCT device to work. The voltage equalizing module can perform voltage equalizing processing on the voltage fluctuation across the IGCT to make the voltage across the IGCT recover to stability in time.

[0063] In this embodiment, the anti-parallel unit can clamp the voltage within a preset threshold range when the voltage across the IGCT device rises abnormally, and this preset threshold range can protect other IGCT devices in the bridge arm sub-module from overvoltage damage.

[0064] It should be noted that a single IGCT device and related circuits in this embodiment can be regarded as an IGCT unit, and for each IGCT unit, corresponding faults may occur during the application process. The faults of the IGCT device unit include energy extraction power supply fault, IGCT drive unit fault, capacitor fault, resistor fault, and IGCT failure, etc.

[0065] In this embodiment, when the energy extraction power supply fails or the IGCT driver fails, at this time the IGCT cannot be normally turned on or off, that is, the IGCT is in an out-of-control state, and at this time the IGCT is in a blocking state. The current of the capacitor bridge arm will charge the energy extraction capacitor in the voltage equalizing module, and the voltage across the IGCT will continuously rise. When it reaches the IGCT turning breakdown value, the IGCT fails rapidly, forming a stable short-circuit state, which can ensure that the designed commutation valve does not have the problem of "any sub-module switching device failure causing the entire system to lock or shut down the commutation valve". The turning breakdown curve of the IGCT is as Figure 7As shown in the figure, where Vak represents the voltage value of the IGCT device at the moment of breakdown, that is, the breakdown voltage. Iak represents the current value flowing through the IGCT device at the breakdown voltage, that is, the breakdown current. T = 300K represents the absolute temperature of 300 Kelvin, and T = 400K represents the absolute temperature of 400 Kelvin. The dashed curve is the turn - breakdown curve of the IGCT device at an absolute temperature of 400 Kelvin. The solid curve is the turn - breakdown curve of the IGCT device at an absolute temperature of 300 Kelvin.

[0066] In summary, this embodiment provides a bridge arm sub - module. Without setting a bypass switch, there is no need to control the on - off change of the bypass switch during the operation of the converter valve. And by making full use of the fail - short characteristic of the IGCT, it can avoid the entire shutdown of the system due to the failure of a single IGCT unit, greatly improving the stability of the system operation. And it effectively reduces the cost and occupied area of the converter valve, which is more conducive to the application and popularization of the converter valve using the IGCT series topology.

[0067] In one of the embodiments, the number of integrated gate - commutated thyristors is greater than or equal to a preset redundancy quantity threshold, where the preset redundancy quantity threshold is greater than the preset working quantity threshold, and the preset working quantity threshold is the minimum number of integrated gate - commutated thyristor devices when the bridge arm sub - module operates normally.

[0068] In this embodiment, a certain number of redundancies are configured for the series number of IGCT devices to ensure that the normal operation of the system will not be affected when a unit where an IGCT device is located fails.

[0069] The preset working quantity threshold needs to be determined according to the type and characteristics of the IGCT devices actually applied. The difference between the preset redundancy quantity and the preset working quantity should be greater than a certain value. For example, the difference between the preset redundancy quantity and the preset working quantity can be set to be at least 2.

[0070] In one of the embodiments, the voltage - equalizing module includes a dynamic voltage - equalizing unit and a static voltage - equalizing unit. The dynamic voltage - equalizing unit and the static voltage - equalizing unit are respectively connected in parallel on both sides of the integrated gate - commutated thyristor device.

[0071] In this embodiment, the voltage equalizing module is used to achieve uniform voltage distribution inside the IGCT device. In a high-voltage application environment, the IGCT device may withstand extremely high voltages. If the voltage distribution is uneven, some parts may be damaged due to excessive voltage. By setting up a dynamic voltage equalizing unit and a static voltage equalizing unit in this embodiment, it can ensure that the voltage is evenly distributed throughout the IGCT device, thus avoiding local overvoltage and damage. When overvoltage or overcurrent occurs in the system, the voltage equalizing module can respond quickly and limit the propagation of the fault current by adjusting the voltage distribution, thereby protecting other devices and the system from damage.

[0072] In one embodiment, the dynamic voltage equalizing unit includes an energy-taking capacitor, a rectifying diode, and a first voltage-dividing resistor. One end of the energy-taking capacitor is connected to the cathode of the integrated gate-commutated thyristor, and the other end of the energy-taking capacitor is connected to the cathode of the rectifying diode. The anode of the rectifying diode is connected to the anode of the integrated gate-commutated thyristor. The first voltage-dividing resistor is connected in parallel on both sides of the rectifying diode. The energy-taking power supply is connected in parallel on both sides of the energy-taking capacitor.

[0073] In this embodiment, the dynamic voltage equalizing unit includes an RCD dynamic voltage equalizing circuit, that is, an energy-taking capacitor, a rectifying diode, and a first voltage-dividing resistor. Among them, the first voltage-dividing resistor can also be called a power-consuming resistor. As Figure 8 shown, the energy-taking capacitor includes and . The rectifying diode includes and . The first voltage-dividing resistor includes and . It should be noted that Figure 8 the bridge arm sub-module shown includes 6 IGCT units. Taking the first IGCT as an example for illustration, that is , and .

[0074] During the application process, when the IGBT switches, due to the inconsistent switching speeds of each IGBT, the voltage distribution will be uneven. At this time, through the charging and discharging of the power-consuming resistor and the energy-taking capacitor , and the unidirectional conductivity of the rectifying diode , the excess voltage is distributed to the energy-taking capacitor, thereby achieving dynamic voltage equalization for the IGBT.

[0075] In one embodiment, the static voltage equalizing unit includes a second voltage-dividing resistor. The second voltage-dividing resistor is connected in parallel on both sides of the integrated gate-commutated thyristor. The second voltage-dividing resistor includes resistor and . It should be noted that the resistance value of the second voltage-dividing resistor can be determined according to the voltage level of the commutation valve in the actual application scenario.

[0076] In this embodiment, the principle of static voltage sharing of resistors is to connect a resistor with a certain value in parallel to the IGCT device. When current passes through the IGCT device, the second voltage-dividing resistor will generate a certain voltage drop, thereby limiting the magnitude of the current. Due to the parallel connection of the second voltage-dividing resistor, the voltage distribution on each series element will tend to be balanced.

[0077] Specifically, when the second voltage-dividing resistor is much smaller than the leakage resistance of the IGCT device, the voltage distribution on the IGCT device will mainly depend on the value of the second voltage-dividing resistor. Therefore, by selecting R with the same resistance value, the voltage between each series-connected IGCT device can reach balanced operation, that is, static voltage sharing is achieved.

[0078] In one of the embodiments, the anti-parallel unit includes a diode.

[0079] The cathode of the diode is connected to the anode of the integrated gate-commutated thyristor, and the anode of the diode is connected to the cathode of the integrated gate-commutated thyristor.

[0080] In this embodiment, under the action of a forward voltage, the parallel diode only allows current to flow in one direction; under the action of a reverse voltage, it blocks the current from flowing. When the voltage in the circuit rises abnormally, the reverse diode in the anti-parallel diode will conduct, thereby clamping the voltage at a safe level, thus protecting other components in the circuit from overvoltage damage.

[0081] In this embodiment, the anti-parallel diode can respond to the voltage change in the circuit in a short time. Thus, when a fault occurs in the IGCT device, the system can be quickly protected.

[0082] It can be understood that the above anti-parallel unit can also adopt other forms, not limited to the forms mentioned in the above embodiments, as long as it can achieve the function of voltage clamping.

[0083] To sum up, this embodiment provides a bridge arm sub-module, which does not require a bypass switch to be set, and does not need to control the on-off change of the bypass switch during the operation of the commutation valve. Moreover, by making full use of the fail-short characteristic of the IGCT, it can avoid the entire shutdown of the system due to a single IGCT unit failure, greatly improving the stability of the system operation. And it effectively reduces the cost and occupied area of the commutation valve, which is more conducive to the application and popularization of the commutation valve using the IGCT series topology.

[0084] In addition, a power distribution system is also provided, including the commutation valve device in the foregoing embodiment. The specific structure of the commutation valve device provided in this embodiment can refer to the MCC commutation valve topology described in the foregoing embodiment.

[0085] In the description of this specification, the descriptions referring to terms such as "some embodiments", "other embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0086] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0087] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A bridge arm submodule, characterized in that: include: A plurality of integrated gate-commutated thyristor devices connected in series and an energy-taking power supply, an anti-parallel unit, a voltage-sharing module and a driving unit corresponding to each integrated gate-commutated thyristor device; The anti-parallel unit and the voltage balancing module are connected in parallel on both sides of the integrated gate-commutated thyristor device; The driving unit is connected to the integrated gate-commutated thyristor device, and the energy-taking power source is connected to the driving unit; The energy-taking power source is connected to the voltage-equalizing module and is used to obtain electrical energy from the voltage-equalizing module and supply power to the driving unit.

2. The bridge arm submodule according to claim 1, characterized in that: The number of the integrated gate-commutated thyristors is greater than or equal to a preset redundancy number threshold, wherein the preset redundancy number threshold is greater than a preset working number threshold, and the preset working number threshold is the minimum number of integrated gate-commutated thyristor devices when the bridge arm submodule operates normally.

3. The bridge arm submodule according to claim 1, characterized in that: The pressure equalizing module includes a dynamic pressure equalizing unit and a static pressure equalizing unit; The dynamic voltage balancing unit and the static voltage balancing unit are respectively connected in parallel at two sides of the integrated gate-commutated thyristor device.

4. The bridge arm submodule according to claim 3, characterized in that: The dynamic voltage balancing unit includes an energy-taking capacitor, a rectifier diode and a first voltage-dividing resistor; One end of the energy-taking capacitor is connected to the cathode of the integrated gate-commutated thyristor, the other end of the energy-taking capacitor is connected to the cathode of the rectifier diode, and the anode of the rectifier diode is connected to the anode of the integrated gate-commutated thyristor; The first voltage-dividing resistor is connected in parallel on both sides of the rectifier diode; The energy-taking power source is connected in parallel to two sides of the energy-taking capacitor.

5. The bridge arm submodule according to claim 3, characterized in that: The static voltage balancing unit includes a second voltage dividing resistor; The second voltage-dividing resistor is connected in parallel on both sides of the integrated gate-commutated thyristor.

6. The bridge arm submodule according to claim 1, characterized in that: The anti-parallel unit includes a diode; The cathode of the diode is connected to the anode of the integrated gate-commutated thyristor, and the anode of the diode is connected to the cathode of the integrated gate-commutated thyristor.

7. A converter valve module, characterized in that: include: A switched capacitor bridge arm, an integrated gate-commutated thyristor device series H-bridge bridge arm and an AC connection reactance connected in sequence; The switch capacitor bridge arm includes a plurality of half-bridge sub-modules connected in cascade, wherein the half-bridge sub-module includes an insulated gate bipolar transistor; the switch capacitor bridge arm is used to access a DC signal; The integrated gate-commutated thyristor device series H-bridge bridge arm comprises four bridge arm submodules according to any one of claims 1 to 6; The output end of the series-connected H-bridge arm of the integrated gate-commutated thyristor device outputs an AC signal through the AC connecting reactance.

8. A converter valve device, characterized in that: include: A DC filter, a converter valve module and a converter transformer connected in sequence; The DC filter is used to access the DC signal and perform filtering on the DC signal; The converter valve module comprises the converter valve module according to claim 7, and the converter valve module is used to convert the DC signal into an intermediate AC signal; The converter transformer is used to perform voltage transformation processing according to the intermediate AC signal output by the converter valve module to output a target AC signal.

9. The converter valve device according to claim 8, characterized in that: The converter valve module includes a first converter valve module, a second converter valve module and a third converter valve module; The switch capacitor bridge arms of the first converter valve module, the second converter valve module and the third converter valve module are connected in cascade; The first converter valve module is used to output a first-phase intermediate AC signal according to the DC signal; The second converter valve module is used to output a second-phase intermediate AC signal according to the DC signal; The third converter valve module is used to output a third-phase intermediate AC signal according to the DC signal.

10. A power distribution system, characterized in that: Comprising the converter valve device according to claim 8 or 9.

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