Disclosure of Invention
The invention aims to provide a modularized multi-level converter control system and a control method, which are used for improving the reliability of a direct current transmission system based on the modularized multi-level converter.
In order to achieve the above purpose, the invention provides a modular multilevel converter control system, which adopts the following technical scheme:
the modular multilevel converter control system comprises: the modular multilevel converter comprises a plurality of sub-modules, each sub-module is connected with the control module, and two adjacent sub-modules are connected with each other.
Compared with the prior art, the modularized multi-level converter control system provided by the invention has the following beneficial effects:
in the control system of the modularized multi-level converter, the submodules in the modularized multi-level converter are connected with the control module, and the adjacent two submodules are connected with each other, so that when the connection between one submodule in the modularized multi-level converter and the control module fails, the control module can not directly transmit signals with the submodules, but the control module can transmit signals with the submodules through the submodules adjacent and connected with the submodules, and further control the submodules, thereby improving the reliability of the direct current transmission system based on the modularized multi-level converter.
The embodiment of the invention also provides a control method of the modularized multi-level converter, which adopts the following technical scheme:
the modularized multi-level converter control method uses the modularized multi-level converter control system to control the modularized multi-level converter, and comprises the following steps:
when any sub-module of the modularized multi-level converter is connected with the control module and fails, the sub-module is a communication failure sub-module; the control module communicates with the communication failure sub-module by connecting adjacent sub-modules of the communication failure sub-module.
Compared with the prior art, the beneficial effects of the modularized multi-level converter control method provided by the invention are the same as those of the modularized multi-level converter control system, so that the description is omitted here.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic structural diagram of a modular multilevel converter control system according to an embodiment of the invention;
fig. 2 is a schematic structural diagram of a power supply circuit of a submodule in a modular multilevel converter according to an embodiment of the present invention.
Reference numerals illustrate:
1-modularized multi-level converter, 11-submodule, 2-control module,
21-pole control system, 22-valve control system, 111-submodule power supply unit,
112-radio energy transmission circuit, 1121-bidirectional conversion circuit, 1122-coil,
3-control loop, 4-energy-taking power supply, 41-main power supply,
42-auxiliary power supply.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1
An embodiment of the present invention provides a modular multilevel converter control system, specifically, as shown in fig. 1, the modular multilevel converter control system includes: the modular multilevel converter 1 and the control module 2 comprise a plurality of sub-modules 11, each sub-module 11 is connected with the control module 2, and two adjacent sub-modules 11 are connected with each other, and illustratively, two adjacent sub-modules 11 can be connected with each other through two unidirectional communication optical fibers.
It should be noted that, in the modular multilevel converter control system provided in the embodiment of the present invention, the topology structure of the sub-module 11 in the modular multilevel converter 1 is not improved, and the topology structure of the sub-module 11 in the modular multilevel converter 1 may be an existing half-bridge structure, a full-bridge structure, or a clamping structure, etc., which is not limited in the embodiment of the present invention.
In the above-mentioned modular multilevel converter control system, when the connection between the submodule 11 and the control module 2 in the modular multilevel converter 1 is normal, the control module 2 can directly transmit signals with the submodule 11 through optical fibers, so as to control and protect the submodule 11; when a connection between a certain sub-module 11 and a control module 2 in the modular multilevel converter fails, the control module 2 cannot directly transmit signals with the sub-module 11, and at this time, the control module 2 can transmit signals with the sub-module 11 through the sub-module 11 adjacent to and connected with the sub-module 11, so as to control the sub-module 11.
In the technical solution of this embodiment, not only the sub-module 11 in the modular multilevel converter 1 is connected with the control module 2, but also two adjacent sub-modules 11 are connected with each other, so when a fault occurs in the connection between a certain sub-module 11 in the modular multilevel converter 1 and the control module 2, the control module 2 can not directly transmit signals with the sub-module 11, but the control module 2 can transmit signals with the sub-module 11 through the sub-module 11 adjacent and connected with the sub-module 11, thereby controlling the sub-module 11, and further improving the reliability of the dc power transmission system based on the modular multilevel converter 1.
For example, as shown in fig. 1, each sub-module 11 may be connected to the control module 2 through a downstream optical fiber and an upstream optical fiber, and other similar connection manners may be adopted to connect the sub-module 11 to the control module 2.
Specifically, when a connection between a certain sub-module 11 of the modular multilevel converter 1 and the control module 2 fails, the control module 2 cannot directly transmit signals with the sub-module 11, and on the one hand, the sub-module 11 with the failed connection with the control module 2 can transmit signals to an adjacent sub-module 11 connected with the sub-module 11 through unidirectional optical fibers, and the adjacent sub-module 11 can transmit signals to the control module 2 through uplink optical fibers; on the other hand, after the control module 2 obtains the signal, the signal for controlling the sub-module 11 can be transmitted to the adjacent sub-module 11 connected with the same through the downlink optical fiber, and the adjacent sub-module 11 transmits the signal for controlling the sub-module 11 to the sub-module through another unidirectional optical fiber, so as to control the sub-module 11.
Alternatively, as shown in fig. 1, the control module 2 includes a pole control system 21 and a valve control system 22 connected to each other, and each sub-module 11 is connected to the valve control system 22.
Illustratively, the pole control system 21 and the valve control system 22 may be interconnected by an on-duty signal fiber, an upstream fiber, and a downstream fiber, respectively.
In addition, as shown in fig. 2, each sub-module 11 may include a sub-module power supply unit 111, and a wireless power transmission circuit 112 for mutually powering adjacent sub-modules 11, where an energy taking power supply 4 for supplying power to the control loop 3 in the control system is provided, and the sub-module power supply unit 111 and the wireless power transmission circuit 112 are respectively connected to the energy taking power supply 4.
It should be noted that, in the control system provided in the embodiment of the present invention, the control system includes a plurality of independent energy-taking power sources 4 and a plurality of independent control loops 3, and each sub-module 11 independently supplies power to one energy-taking power source 4 and one control loop 3.
In the above-mentioned modular multilevel converter control system, when the sub-module power supply unit 111 in any sub-module 11 fails, the sub-module 11 can obtain the electric energy of the sub-module 11 adjacent to and connected with the sub-module through the wireless electric energy transmission circuit 112 provided in the sub-module 11, and supply power to the energy taking power supply 4 connected with the sub-module 11, so that the energy taking power supply 4 supplies power to the control loop 3.
Alternatively, as shown in fig. 2, the wireless power transmission circuit 112 includes a bidirectional conversion circuit 1121 and a coil 1122 connected to each other, and the bidirectional conversion circuit 1121 is connected to the power source 4.
Illustratively, as shown in fig. 2, the power supply 4 includes a main power supply 41 and an auxiliary power supply 42, the sub-module power supply unit 111 is connected to the main power supply 41 and the auxiliary power supply 42, respectively, and the wireless power transmission circuit 112 is connected to the auxiliary power supply 42.
Specifically, when the sub-module power supply unit 111 and the main power supply 41 in the sub-module 11 work normally, the main power supply 41 takes energy from a high position of the sub-module power supply unit 111 through a capacitor in the sub-module power supply unit 111 to supply power to the control loop 3, and the auxiliary power supply 42 does not work at this time; when the sub-module power supply unit 111 works normally and the main power supply 41 fails, the auxiliary power supply 42 can take energy from the high position of the sub-module power supply unit 111 through the capacitor in the sub-module power supply unit 111 to supply power for the control loop 3; when the sub-module power supply unit 111 in the sub-module 11 fails, the auxiliary power supply 42 can receive the power provided by the sub-module 11 adjacent to the sub-module 11 through the wireless power transmission circuit 112 and the coil 1122 connected with the auxiliary power supply 42, and the auxiliary power supply 42 in the sub-module 11 adjacent to the auxiliary power supply receives power from the sub-module power supply unit 111 in the sub-module 11 and transmits the power to the failed sub-module 11 through the wireless power transmission circuit 112 and the coil 1122 in the sub-module 11.
Example two
The embodiment of the invention provides a control method of a modularized multi-level converter, which is used for controlling the modularized multi-level converter by using the control system of the modularized multi-level converter provided in the first embodiment of the invention, and concretely comprises the following steps: when any sub-module in the modularized multi-level converter is connected with the control module and fails, the sub-module is a communication failure sub-module; the control module communicates with the communication failure sub-module by connecting adjacent sub-modules of the communication failure sub-module.
For example, as shown in fig. 1, when a connection between a certain sub-module 11 and a control module 2 in the modular multilevel converter fails, the control module 2 cannot directly transmit signals to the sub-module 11, and at this time, the control module 2 may transmit signals to the sub-module 11 through the sub-module 11 adjacent to and connected to the sub-module 11, so as to control the sub-module 11.
In the technical solution of this embodiment, when a connection between a certain sub-module and a control module in the modular multilevel converter fails, the control module can communicate with the communication failure sub-module by connecting the sub-module of the communication failure sub-module, so as to control the communication failure sub-module, thereby improving the reliability of the dc power transmission system based on the modular multilevel converter.
In addition, the modular multilevel converter control method further comprises the following steps:
when the power supply unit of any sub-module fails, the sub-module is a power failure sub-module, and the power failure sub-module acquires the electric energy of the sub-module adjacent to the power failure sub-module through a wireless electric energy transmission circuit in the power failure sub-module, and supplies power to an energy taking power supply connected with the power failure sub-module, so that the energy taking power supply supplies power to a control loop.
Illustratively, as shown in fig. 2, when the sub-module power supply unit 111 in the sub-module 11 fails, the auxiliary power supply 42 may receive the power provided by the sub-module 11 adjacent to the sub-module 11 through the wireless power transmission circuit 112 and the coil 1122 connected thereto, and the auxiliary power supply 42 in the sub-module 11 adjacent thereto may take high-level power from the sub-module power supply unit 111 in the sub-module 11 and transmit the power to the failed sub-module 11 through the wireless power transmission circuit 112 and the coil 1122 in the sub-module 11.
The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.