CN115885463A

CN115885463A - Submodule, control system, method and device of modular multilevel converter

Info

Publication number: CN115885463A
Application number: CN202080103367.XA
Authority: CN
Inventors: 赵研峰; 姚吉隆; 石磊
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2020-09-28
Filing date: 2020-09-28
Publication date: 2023-03-31
Also published as: WO2022061927A1

Abstract

A submodule, a control system, a method and a device of a Modular Multilevel Converter (MMC). A sub-module (70) of a modular multilevel converter comprises: a sensor module (50) adapted to detect a parameter of the sub-module (70); a wireless communication module (61) adapted to establish a first wireless communication connection with a control system; a processor (71) adapted to send a first notification message comprising the parameter to the control system based on the first wireless communication connection and/or to receive a first control instruction from the control system based on the first wireless communication connection. A sub-module (70) with wireless communication capability is realized, which may reduce costs. And a distributed control is realized, and the safety problem of centralized control can be overcome.

Description

Submodule, control system, method and device of modular multilevel converter

Technical Field

The present disclosure relates to the field of Modular Multilevel Converters (MMC), and more particularly, to a submodule, a control system, a control method, and a device of an MMC.

Background

The MMC is a novel voltage conversion circuit, can superpose and output very high voltage by cascading a plurality of submodules, and has the characteristics of less output harmonic waves, high modularization degree and the like, so that the MMC has wide application prospect in a power system. Currently common sub-module topologies include half-bridge and full-bridge sub-modules, among others. The half-bridge type sub-module is most commonly applied in current engineering, but the half-bridge type sub-module does not have direct current fault ride-through capability and needs to be cut off by means of an alternating current breaker. The full-bridge submodule has direct-current fault ride-through capability, but large-scale engineering application is not available at present due to large investment and operation loss.

In the prior art, a unified central control unit centrally controls the sending of control commands to the sub-modules via optical fibers. However, fiber optic communication has cost issues and the fiber is prone to becoming a fault bottleneck.

In addition, the centralized control approach has safety issues. For example, when the central control unit fails, all the sub-modules are disabled. Moreover, the control functions of all the sub-modules are centralized to be executed by a unified central control unit, and the real-time performance of the MMC can be reduced.

Disclosure of Invention

In view of the above, the present invention provides a submodule, a control system, a method and a device for an MMC.

The technical scheme of the embodiment of the invention is realized as follows:

a sub-module of an MMC comprising:

a sensor module adapted to detect a parameter of the sub-module;

a wireless communication module adapted to establish a first wireless communication connection with a control system;

a processor adapted to send a first notification message including the parameter to the control system based on the first wireless communication connection and/or to receive a first control instruction from the control system based on the first wireless communication connection.

Therefore, the sub-module with the wireless communication capability is realized, optical fibers are not needed to be adopted for communicating with the outside, the hardware cost can be reduced, and the fault bottleneck defect of the optical fibers is overcome.

In one embodiment, further comprising:

a commutation module adapted for commutation;

a processor further adapted to receive a second notification message from the control system containing a target electrical property value of the MMC based on the first wireless communication connection;

a wireless communication module further adapted to establish a second wireless communication connection with other sub-modules in the MMC;

a processor further adapted to receive a third notification message from the other sub-module containing parameters of the other sub-module based on the second wireless communication connection, determine a second control instruction for controlling the commutation module based on the target electrical property value and the parameters of the other sub-module.

Therefore, the sub-module of the embodiment of the invention can also generate a second control instruction for controlling the current conversion module in the sub-module based on the target electrical property value and the parameters of other sub-modules. Therefore, the sub-modules have a control function, the defect that faults are easily caused when the control function is centralized to the central control unit is overcome, and the real-time performance of the MMC is improved.

In one embodiment, the commutation module comprises a half-bridge sub-module circuit configuration or a full-bridge sub-module circuit configuration.

Therefore, the commutation module has various circuit configurations.

In one embodiment, the wireless communication module includes at least one of:

a WI-FI module; a Zigbee module; a Bluetooth module; a second generation mobile communication module; a third generation mobile communication module; a fourth generation mobile communication module; a fifth generation mobile communication module; and/or

The sensor module includes at least one of: a current sensor; a voltage sensor; a temperature sensor.

Therefore, the wireless communication module and the sensor module have various implementation modes and wide application range.

An MMC comprising a sub-module as claimed in any preceding claim.

Accordingly, an MMC comprising a sub-module with wireless communication capabilities is proposed.

A control system of an MMC comprises N sub-modules, wherein N is a positive integer of at least 2, and each sub-module comprises a respective wireless communication module; the control system includes:

a user terminal adapted to receive notification messages containing parameters of the respective sub-modules from each sub-module, respectively, based on a wireless communication connection with the wireless communication module of each sub-module;

and the configuration terminal is adapted to send a control instruction to each sub-module respectively based on the wireless communication connection with the wireless communication module of each sub-module.

Therefore, the embodiment of the invention realizes a control system based on wireless communication, which not only saves the hardware cost, but also overcomes the fault bottleneck defect of optical fibers.

In one embodiment, the wireless communication module is a Zigbee module;

wherein the N Zigbee modules of the N sub-modules are networked in a star topology, a tree topology, or a mesh topology.

Thus, zigbee modules can be networked in a variety of ways.

A method of controlling an MMC, the modular multilevel converter comprising N sub-modules, each sub-module containing a respective wireless communication module, where N is a positive integer greater than or equal to 2, the method comprising:

enabling each of the N sub-modules to detect parameters of the respective sub-module;

enabling each of the N sub-modules to establish a first wireless communication connection with a control system;

enabling each of the N sub-modules to send a first notification message containing the parameter to the control system based on the first wireless communication connection and/or to receive a first control instruction from the control system based on the first wireless communication connection.

Therefore, the embodiment of the invention realizes the MMC control method based on wireless communication, which not only saves the hardware cost, but also overcomes the fault bottleneck defect of optical fibers.

In one embodiment, the method further comprises:

enabling each of the N sub-modules to receive a second notification message from the control system containing a target electrical property value of the modular multilevel converter based on the first wireless communication connection;

enabling each of the N sub-modules to establish a second wireless communication connection with other sub-modules in the modular multilevel converter;

enabling each of the N sub-modules to receive a third notification message from the other sub-module containing parameters of the other sub-module based on the second wireless communication connection;

enabling each of the N sub-modules to determine a second control instruction for controlling a commutation module of the respective sub-module based on the target electrical property value and the parameters of the other sub-modules.

A control apparatus for an MMC, the MMC comprising N sub-modules, each sub-module containing a respective wireless communication module, wherein N is a positive integer greater than or equal to 2, the apparatus comprising:

a first enabling module adapted to enable each of the N sub-modules to detect parameters of the respective sub-module;

a second enabling module adapted to enable each of the N sub-modules to establish a first wireless communication connection with a control system;

a third enabling module adapted to enable each of the N sub-modules to send a first notification message containing the parameter to the control system based on the first wireless communication connection and/or to receive a first control instruction from the control system based on the first wireless communication connection.

Therefore, the embodiment of the invention realizes the MMC control device based on wireless communication, not only saves the hardware cost, but also overcomes the fault bottleneck defect of optical fiber

In one embodiment, further comprising:

a fourth enabling module adapted to enable each of the N sub-modules to receive a second notification message containing a target electrical property value of the MMC from the control system based on the first wireless communication connection;

a fifth enabling module adapted to enable each of the N sub-modules to establish a second wireless communication connection with other sub-modules in the MMC;

a sixth enabling module adapted to enable each of the N sub-modules to receive a third notification message containing parameters of the other sub-module from the other sub-module based on the second wireless communication connection;

a seventh enabling module adapted to enable each of the N sub-modules to determine a second control command for controlling a commutation module of the respective sub-module based on the target electrical property value and the parameters of the other sub-modules.

A control device of MMC comprises a processor and a memory;

the memory stores therein an application program executable by the processor for causing the processor to execute the MMC control method as described above.

Therefore, the MMC control device with a processor-memory architecture is provided, optical fibers are not needed to be adopted for external communication, the hardware cost can be reduced, and the fault bottleneck defect of the optical fibers is overcome.

A computer readable storage medium having stored therein computer readable instructions for executing the control method of the MMC as described above.

Therefore, the computer readable storage medium containing the computer readable instructions is provided, optical fiber is not needed to be adopted for communicating with the outside, the hardware cost can be reduced, and the fault bottleneck defect of the optical fiber is overcome.

Drawings

Fig. 1 is an exemplary block diagram of sub-modules of an MMC according to an embodiment of the present invention.

Fig. 2 is a first exemplary block diagram of a control system of an MMC according to an embodiment of the present invention.

Fig. 3 is a second exemplary block diagram of a control system of an MMC according to an embodiment of the present invention.

Fig. 4 is a flowchart of a control method of an MMC according to an embodiment of the present invention.

Fig. 5 is a structural diagram of a control apparatus of an MMC according to an embodiment of the present invention.

Fig. 6 is a block diagram of a control apparatus of an MMC having a processor-memory architecture according to an embodiment of the present invention.

Fig. 7 is an exemplary structural diagram of an MMC according to an embodiment of the present invention.

Wherein the reference numbers are as follows:

reference numerals	Means of
70	Submodule
40	Current conversion module
50	Sensor module
60	Communication module
71	Processor with a memory having a plurality of memory cells
51	Current sensor
52	Voltage sensor

53	Temperature sensor
61	Wireless communication module
62	Processor interface
41	Drive protection circuit
42	Current conversion module
100	Control system of modular multilevel converter
80	MMC
10	Zigbee gateway
11	Communication network
12	User terminal
13	Configuration terminal
70a	Zigbee module as coordinator
200	MMC control system
90	MMC
400	MMC control method
401～407	Step (ii) of
500	MMC control device
501	First enabling module
502	Second enabling module
503	Third enabling module
504	Fourth enabling module
505	Fifth enabling module
506	Sixth enabling module
507	Seventh enabling module
600	MMC control device
601	Processor with a memory having a plurality of memory cells
602	Memory device
20	MMC
31	A phase circuit
32	B-phase circuit
33	C-phase circuit
311	First half bridge circuit
312	Second half-bridge circuit
313，314	Current equalizing inductor

Detailed Description

In order to make the technical scheme and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the detailed description and specific examples, while indicating the scope of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

For simplicity and clarity of description, the invention will be described below by describing several representative embodiments. Numerous details of the embodiments are set forth to provide an understanding of the principles of the invention. It will be apparent, however, that the invention may be practiced without these specific details. Some embodiments are not described in detail, but rather are merely provided as frameworks, in order to avoid unnecessarily obscuring aspects of the invention. Hereinafter, "comprising" means "including but not limited to", "according to '8230;' 8230;" means "according to at least '8230;' 8230;, but not limited to only according to '8230;' 8230;". In view of the language convention for chinese, the following description, when not specifically referring to the number of a component, means that the component may be one or more than one, or may be understood as at least one.

The embodiment of the invention provides a sub-module with wireless communication capability, which does not need to adopt optical fiber for external communication, can reduce the hardware cost, overcomes the fault bottleneck defect of the optical fiber,

As shown in fig. 1, the sub-module 70 includes:

a sensor module 50 adapted to detect a parameter of the sub-module 70;

a wireless communication module 61 adapted to establish a first wireless communication connection with a control system;

a processor 71 adapted to send a first notification message comprising the parameter to the control system based on the first wireless communication connection and/or to receive a first control instruction from the control system based on the first wireless communication connection.

In one embodiment, the wireless communication module 61 includes at least one of: a WI-FI module; a Zigbee module; a Bluetooth module; a second generation mobile communication module; a third generation mobile communication module; a fourth generation mobile communication module; a fifth generation mobile communication module; and so on.

In one embodiment, the sensor module 50 includes at least one of: a current sensor; a voltage sensor; temperature sensors, etc. When the sensor module 50 includes the current sensor 51, the current sensor 51 detects the current of the sub-module 70; when the sensor module 50 contains the voltage sensor 52, the voltage sensor 52 detects the voltage of the sub-module 70; when the sensor module 50 contains the temperature sensor 53, the temperature sensor 53 detects the temperature of the sub-module 70.

Sub-module 70 also includes processor interface 62. The wireless communication module 61 is coupled with the processor 71 via the processor interface 62. The wireless communication module 61 receives a first control command from the control system based on the first wireless communication connection, and then transmits the first control command to the processor 71 via the processor interface 62, so that the processor 71 executes the first control command. The processor 71 generates a first notification message containing the parameter based on the detection value of the sensor module 50 and transmits the first notification message to the wireless communication module 61 via the processor interface 62, so that the first notification message is transmitted to the control system by the wireless communication module 61 based on the first wireless communication connection. The processor interface 62 and the wireless communication module 61 may be integrated as the communication module 60.

While the above exemplary description describes exemplary examples of the sensor module 50 and the wireless communication module 61, those skilled in the art will appreciate that this description is merely exemplary and is not intended to limit the scope of embodiments of the present invention.

In one embodiment, the sub-module 70 further includes: a commutation module 40 adapted for commutation; a processor 71 further adapted to receive a second notification message containing a target electrical property value of the MMC from the control system based on the first wireless communication connection; a wireless communication module 61 further adapted to establish a second wireless communication connection with other sub-modules in the MMC; a processor 71 further adapted to receive third notification messages containing parameters of other sub-modules from said other sub-modules based on said second wireless communication connection, and to determine second control instructions for controlling said commutation module 40 based on said target electrical property value and said parameters of said other sub-modules.

Examples are: when the target electrical property value in the second notification message is a positive voltage of 50KV, that is, the control system issues the second notification message that the MMC is expected to output a positive voltage of 50KV, and the processor 71 sums the output voltages provided by the other sub-modules, and determines that the current MMC does not reach a positive voltage of 50KV (for example, only 40 KV), an instruction for controlling the switching-in or switching-out of the commutation module 40 is generated. For example, if the current sub-module is located on the upper arm, the commutation module 40 is put into operation to increase the output positive voltage; if the front sub-module is in the lower arm, the commutation module 40 switches out to reduce the output negative voltage.

Therefore, the sub-module of the embodiment of the invention can also generate a second control instruction for controlling the self current conversion module based on the target electrical property value and the parameters of other sub-modules. Therefore, the sub-modules have a control function, the defect that faults are easily caused when the control function is centralized to the central control unit is overcome, and the real-time performance of the MMC is improved.

Preferably, the sub-module 70 may be implemented as a half-bridge sub-module or a full-bridge sub-module, or the like.

Based on the above description, the embodiment of the invention also provides an MMC. The MMC comprises a sub-module 70 as described above.

A typical structure of the MMC of the embodiment of the present invention is described below. Fig. 7 is an exemplary structural diagram of an MMC according to an embodiment of the present invention.

As shown in fig. 7, the MMC20 includes:

phase-A circuit 31 and DC power supply U _dc Connecting;

b phase circuit 32, and DC power supply U _dc Connecting;

c-phase circuit 33, and DC power supply U _dc Connecting;

wherein the a-phase circuit 31, the B-phase circuit 32, and the C-phase circuit 33 have the same first circuit topology; the first circuit topology includes: a first half bridge circuit 311; a second half-bridge circuit 312; two current sharing inductors 313, 314 connected in series between the first half-bridge circuit 311 and the second half-bridge circuit 312; wherein the first half-bridge circuit 311 and the second half-bridge circuit 312 have the same second circuit topology; the second circuit topology contains a plurality of sub-modules 70 as described above.

In fig. 7, the number of sub-modules 70 in the first half-bridge circuit 311 may be conveniently increased to boost the output voltage of the MMC20, and the number of sub-modules 70 in the second half-bridge circuit 312 may be conveniently decreased to lower the output voltage of the MMC 20.

The above exemplary description describes a typical structure of the MMC20 including the sub-module 70, and those skilled in the art will appreciate that this description is merely exemplary and is not intended to limit the scope of the embodiments of the present invention.

Based on the above description, the embodiment of the invention also provides a control system of the MMC. The MMC may comprise N sub-modules 70 as shown in fig. 1, N being a positive integer of at least 2, each sub-module 70 containing a respective wireless communication module 61. Specifically, the control system includes: a user terminal adapted to receive a notification message containing parameters of the respective sub-module from each sub-module 70, respectively, based on a wireless communication connection with the wireless communication module 61 of each sub-module 70; and a configuration terminal adapted to send a control instruction to each sub-module 70, respectively, based on the wireless communication connection with the wireless communication module 61 of each sub-module.

Preferably, the wireless communication module 61 is implemented as a Zigbee module. Zigbee is a wireless network technology with short distance, low power consumption and low data transmission rate, is a technical scheme between a wireless marking technology and Bluetooth, is widely applied to the fields of sensor networks and the like, and can form Zigbee networks such as star-shaped networks, tree-shaped networks, network-shaped networks and the like due to the strong networking capability. Accordingly, N Zigbee modules of the N sub-modules in the MMC may be networked in a star topology, a tree topology, or a mesh topology.

In fig. 2, N Zigbee modules of the N sub-modules 70 in the MMC80 are networked in a star topology. Therein, a sub-module 70a including a Zigbee module as a coordinator (coordinator) is connected to the Zigbee gateway 10. The user terminal 12 and the configuration terminal 13 are connected to the Zigbee gateway 10 via the communication network 11, respectively.

Each of the N sub-modules 70, which are Zigbee nodes, implements information forwarding with the exception of the MMC80 via the sub-module 70 a. For example, it may be implemented to send a notification message containing parameters of each sub-module 70 to the user terminal 12, or receive a control instruction about each sub-module 70 from the configuration terminal 13. Preferably, the Zigbee module 70a as the coordinator is further included, and sub-module control functions are integrated on the sub-module 70 a. The sub-module 70a determines the sub-module on or off according to the state of the MMC 80.

Examples are as follows: when the sub-module 70a receives the notification message containing the target electrical property value (positive voltage of 50 KV) from the user terminal 12, that is, the control system issues a notification message to the sub-module 70a that the MMC80 is expected to output a positive voltage of 50 KV. The sub-module 70a receives the electrical property values (e.g., output voltages) of the respective sub-modules 70 of the MMC80 except for the sub-module 70 a. The processor 71 in the sub-module 70a sums the output voltages provided by the sub-modules 70 to determine that the MMC80 is not equal to a positive voltage of 50KV (e.g., 30KV only or 60 KV), and generates an instruction for controlling the switching in or out of each sub-module 70 other than the sub-module 70a in the MMC80, thereby ensuring that the MMC80 reaches the target electrical property value. For example, when the current output voltage of the MMC80 is smaller than the target electrical property value, the number of investments of the sub-modules of the upper arm is increased to increase the output of a positive voltage by the MMC 80; when the present output voltage of the MMC80 is greater than the target electrical property value, the number of invested sub-modules of the lower arm is increased to decrease the output positive voltage of the MMC 80.

Fig. 3 is a second exemplary block diagram of a control system of a modular multilevel converter according to an embodiment of the invention.

In fig. 3, N Zigbee modules of the N sub-modules 70 in the MMC90 are in a mesh topology. A sub-module 70a including a Zigbee module as a coordinator is connected to the Zigbee gateway 10. The user terminal 12 and the configuration terminal 13 are connected to the Zigbee gateway 10 via the communication network 11, respectively.

The sub-modules closer to the sub-module 70a implement information forwarding with the MMC90 via the sub-module 70a, such as sending a notification message containing parameters of the respective sub-modules to the user terminal 12, and receiving control instructions from the configuration terminal 13. The sub-modules far from the sub-module 70a are connected to the sub-module 70a via the routing function of the sub-modules serving as routers in the vicinity, thereby realizing transmission of notification messages including parameters of the respective sub-modules to the user terminal 12 and reception of control commands from the configuration terminal 13. Preferably, the Zigbee module 70a as the coordinator is further included, and sub-module control functions are integrated on the sub-module 70 a. The sub-module 70a determines the sub-module to be put in or put out according to the state of the MMC 90.

Examples are: when the sub-module 70a receives the notification message containing the target electrical property value (positive voltage of 80 KV) from the user terminal 12, that is, the control system issues the notification message to the sub-module 70a that the MMC90 is expected to output the positive voltage of 80 KV. The sub-module 70a receives the electrical property values (e.g., output voltages) of the respective sub-modules 70 of the MMC90 except for the sub-module 70 a. The processor 71 in the sub-module 70a sums the output voltages provided by the respective sub-modules 70, determines that the MMC90 is not equal to a positive voltage of 80KV (e.g., 50KV only or 100 KV), and generates an instruction for controlling the switching in or out of the respective sub-modules 70 other than the sub-module 70a in the MMC90, thereby ensuring that the MMC90 reaches the target electrical property value. For example, when the current output voltage of the MMC90 is smaller than the target electrical property value, the number of invested submodules of the upper arm is increased to increase the output positive voltage of the MMC 90; when the current output voltage of the MMC90 is greater than the target electrical property value, the number of invested sub-modules of the lower arm is increased to decrease the output positive voltage of the MMC 90.

Based on the above description, the embodiment of the present invention further provides a control method of an MMC.

Fig. 4 is a flowchart of a control method of an MMC according to an embodiment of the present invention. For example, the MMC may comprise N sub-modules 70 as shown in fig. 1, each sub-module 70 containing a respective wireless communication module 61, where N is a positive integer greater than or equal to 2.

As shown in fig. 4, the method 400 includes:

step 401: enabling each of the N sub-modules to detect parameters of the respective sub-module.

Step 402: enabling each of the N sub-modules to establish a first wireless communication connection with a control system.

Step 403: enabling each of the N sub-modules to send a first notification message containing the parameter to the control system based on the first wireless communication connection and/or to receive a first control instruction from the control system based on the first wireless communication connection.

In one embodiment, the method 400 further comprises:

step 404: enabling each of the N sub-modules to receive a second notification message containing a target electrical property value of the MMC from the control system based on the first wireless communication connection.

Step 405: enabling each of the N sub-modules to establish a second wireless communication connection with other sub-modules in the MMC.

Step 406: enabling each of the N sub-modules to receive a third notification message from the other sub-module 70 containing parameters of the other sub-module based on the second wireless communication connection.

Step 407: enabling each of the N sub-modules to determine a second control instruction for controlling a commutation module of the respective sub-module based on the target electrical property value and the parameters of the other sub-modules.

Based on the above description, the embodiment of the invention also provides a control device of the MMC.

Fig. 5 is a block diagram of a control apparatus of an MMC according to an embodiment of the present invention. For example, the MMC may comprise N sub-modules 70 as shown in fig. 1, each sub-module 70 containing a respective wireless communication module 61, where N is a positive integer greater than or equal to 2.

As shown in fig. 5, the apparatus 500 includes: a first enabling module 501 adapted to enable each of the N sub-modules to detect parameters of the respective sub-module; a second enabling module 502 adapted to enable each of the N sub-modules to establish a first wireless communication connection with a control system; a third enabling module 503 adapted to enable each of the N sub-modules to send a first notification message containing the parameter to the control system based on the first wireless communication connection and/or to receive a first control instruction from the control system based on the first wireless communication connection.

In one embodiment, the apparatus 500 further comprises: a fourth enabling module 504 adapted to enable each of the N sub-modules to receive a second notification message from the control system containing a target electrical property value of the modular multilevel converter based on the first wireless communication connection; a fifth enabling module 505 adapted to enable each of the N sub-modules to establish a second wireless communication connection with other sub-modules of the modular multilevel converter; a sixth enabling module 506 adapted to enable each sub-module of the N sub-modules to receive a third notification message containing parameters of the other sub-module from the other sub-module based on the second wireless communication connection; a seventh enabling module 507 adapted to enable each of said N sub-modules to determine second control instructions for controlling a commutation module of said respective sub-module based on said target electrical property value and parameters of said other sub-modules.

Fig. 6 is a structural diagram of a control apparatus of an MMC according to an embodiment of the present invention.

As shown in fig. 6, the control device includes a processor 601 and a memory 602; the memory 602 stores therein an application program executable by the processor 601 for causing the processor 601 to execute the MMC control method according to any one of the above.

The embodiment of the present invention further provides a computer-readable storage medium, in which computer-readable instructions are stored, and the computer-readable instructions are used for executing the method for controlling a modular multilevel converter according to any one of the above descriptions.

It should be noted that not all steps and modules in the above flows and structures are necessary, and some steps or modules may be omitted according to actual needs. The execution order of the steps is not fixed and can be adjusted as required. The division of each module is only for convenience of describing adopted functional division, and in actual implementation, one module may be divided into multiple modules, and the functions of multiple modules may also be implemented by the same module, and these modules may be located in the same device or in different devices.

The hardware modules in the various embodiments may be implemented mechanically or electronically. For example, a hardware module may include a specially designed permanent circuit or logic device (e.g., a special purpose processor such as an FPGA or ASIC) for performing specific operations. A hardware module may also include programmable logic devices or circuits (e.g., including a general-purpose processor or other programmable processor) that are temporarily configured by software to perform certain operations. The implementation of the hardware module in a mechanical manner, or in a dedicated permanent circuit, or in a temporarily configured circuit (e.g., configured by software), may be determined based on cost and time considerations.

The present invention also provides a machine-readable storage medium storing instructions for causing a machine to perform a method as described herein. Specifically, a system or an apparatus equipped with a storage medium on which a software program code that realizes the functions of any of the embodiments described above is stored may be provided, and a computer (or a CPU or MPU) of the system or the apparatus is caused to read out and execute the program code stored in the storage medium. Further, part or all of the actual operations may also be performed by an operating system or the like operating on the computer by instructions based on the program code. The functions of any of the above-described embodiments may also be implemented by writing the program code read out from the storage medium to a memory provided in an expansion board inserted into the computer or to a memory provided in an expansion unit connected to the computer, and then causing a CPU or the like mounted on the expansion board or the expansion unit to perform part or all of the actual operations based on the instructions of the program code. Embodiments of the storage medium for supplying the program code include a floppy disk, a hard disk, a magneto-optical disk, an optical disk (e.g., CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD + RW), a magnetic tape, a nonvolatile memory card, and a ROM. Alternatively, the program code may be downloaded from a server computer via a communications network.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

A sub-module (70) of a modular multilevel converter, comprising:

a sensor module (50) adapted to detect a parameter of the sub-module (70);

a wireless communication module (61) adapted to establish a first wireless communication connection with a control system;

a processor (71) adapted to send a first notification message comprising the parameter to the control system based on the first wireless communication connection and/or to receive a first control instruction from the control system based on the first wireless communication connection.
The sub-module (70) of the modular multilevel converter of claim 1, further comprising:

a commutation module (40) adapted for commutation;

wherein the processor (71) is further adapted to receive a second notification message including a target electrical property value of the modular multilevel converter from the control system based on the first wireless communication connection;

the wireless communication module (61) is further adapted to establish a second wireless communication connection with other sub-modules in the modular multilevel converter;

the processor (71) is further adapted to receive a third notification message from the other sub-module containing parameters of the other sub-module based on the second wireless communication connection, and to determine a second control instruction for controlling the commutation module (40) based on the target electrical property value and the parameters of the other sub-module.
The sub-module (70) of the modular multilevel converter of claim 1, wherein the converter module (40) comprises a half-bridge sub-module circuit structure or a full-bridge sub-module circuit structure.
Sub-module (70) of a modular multilevel converter according to claim 1, characterized in that,

the wireless communication module (61) comprises at least one of: a WI-FI module; a Zigbee module; a Bluetooth module; a second generation mobile communication module; a third generation mobile communication module; a fourth generation mobile communication module; a fifth generation mobile communication module; and/or

The sensor module (50) comprises at least one of: a current sensor (51); a voltage sensor (52); a temperature sensor (53).
A modular multilevel converter comprising a sub-module (70) according to any of claims 1-4.
A control system (100, 200) for a modular multilevel converter, the modular multilevel converter comprising N sub-modules (70), N being a positive integer of at least 2, each sub-module (70) comprising a respective wireless communication module (61); the control system (100, 200) comprises:

a user terminal (12) adapted to receive from each sub-module (70) a notification message containing parameters of the respective sub-module (70), respectively, based on a wireless communication connection with the wireless communication module (61) of each sub-module (70);

a configuration terminal (13) adapted to send control instructions to each sub-module (70) individually based on a wireless communication connection with the wireless communication module (61) of each sub-module (70).
The control system (100, 200) of a modular multilevel converter according to claim 6, wherein the wireless communication module (61) is a Zigbee module;

wherein N Zigbee modules of the N sub-modules (70) are networked in a star topology, a tree topology or a mesh topology.
A method (400) for controlling a modular multilevel converter, the modular multilevel converter comprising N sub-modules, each sub-module containing a respective wireless communication module, wherein N is a positive integer greater than or equal to 2, the method (400) comprising:

enabling each of the N sub-modules to detect parameters of the respective sub-module (401);

enabling each of the N sub-modules to establish a first wireless communication connection with a control system (402);

enabling each of the N sub-modules to send a first notification message containing the parameter to the control system based on the first wireless communication connection and/or to receive a first control instruction from the control system based on the first wireless communication connection (403).
The method (400) of controlling a modular multilevel converter according to claim 8, the method (400) further comprising:

enabling each of the N sub-modules to receive a second notification message containing a target electrical property value of the modular multilevel converter from the control system based on the first wireless communication connection (404);

enabling each of the N sub-modules to establish a second wireless communication connection with other sub-modules in the modular multilevel converter (405);

enabling each of the N sub-modules to receive a third notification message containing parameters of the other sub-module from the other sub-module based on the second wireless communication connection (406);

enabling each of the N sub-modules to determine a second control instruction (407) for controlling a commutation module of the respective sub-module based on the target electrical property value and the parameters of the other sub-modules.
A control apparatus (500) for a modular multilevel converter, the modular multilevel converter comprising N sub-modules, each sub-module containing a respective wireless communication module, wherein N is a positive integer greater than or equal to 2, the apparatus (500) comprising:

a first enabling module (501) adapted to enable each of the N sub-modules to detect parameters of the respective sub-module;

a second enabling module (502) adapted to enable each of the N sub-modules to establish a first wireless communication connection with a control system;

a third enabling module (503) adapted to enable each of the N sub-modules to send a first notification message containing the parameter to the control system based on the first wireless communication connection and/or to receive a first control instruction from the control system based on the first wireless communication connection.
The control device (500) of a modular multilevel converter according to claim 10, further comprising:

a fourth enabling module (504) adapted to enable each of the N sub-modules to receive a second notification message from the control system containing a target electrical property value of the modular multilevel converter based on the first wireless communication connection;

a fifth enabling module (505) adapted to enable each of the N sub-modules to establish a second wireless communication connection with other sub-modules in the modular multilevel converter;

a sixth enabling module (506) adapted to enable each sub-module of the N sub-modules to receive a third notification message containing parameters of the other sub-module from the other sub-module based on the second wireless communication connection;

a seventh enabling module (507) adapted to enable each of the N sub-modules to determine second control instructions for controlling a commutation module of the respective sub-module based on the target electrical property value and the parameters of the other sub-modules.
A control device (600) for a modular multilevel converter, comprising a processor (601) and a memory (602);

the memory (602) has stored therein an application program executable by the processor (601) for causing the processor (601) to execute the method (400) of controlling a modular multilevel converter according to claim 8 or 9.
A computer readable storage medium, having stored therein computer readable instructions for performing the method (400) of controlling a modular multilevel converter according to claim 8 or 9.