CN114784786A - Control method and device for direct-current bus voltage, direct-current micro-grid system and storage medium - Google Patents
Control method and device for direct-current bus voltage, direct-current micro-grid system and storage medium Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/10—Parallel operation of dc sources
- H02J1/102—Parallel operation of dc sources being switching converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/10—Parallel operation of dc sources
- H02J1/109—Scheduling or re-scheduling the operation of the DC sources in a particular order, e.g. connecting or disconnecting the sources in sequential, alternating or in subsets, to meet a given demand
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J1/00—Circuit arrangements for dc mains or dc distribution networks
- H02J1/14—Balancing the load in a network
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/381—Dispersed generators
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
- H02J2300/20—The dispersed energy generation being of renewable origin
- H02J2300/28—The renewable source being wind energy
Abstract
The embodiment of the application provides a method and a device for controlling direct-current bus voltage, a direct-current micro-grid system and a storage medium, wherein the method comprises the following steps: under the condition that the load requirement of the direct current microgrid is detected, the wind turbine generator is merged into the direct current microgrid through the AC/DC converter; detecting the voltage of the direct-current bus in real time, and determining whether the voltage of the direct-current bus is increased or decreased; under the condition that the voltage of the direct current bus is increased, adjusting a first parameter of the wind turbine generator so as to enable the voltage of the direct current bus to be reduced to a set interval; and under the condition that the voltage of the direct current bus is reduced, adjusting a second parameter of the wind turbine generator so as to enable the voltage of the direct current bus to rise to a set interval. Compared with the traditional method for controlling the voltage stability of the direct current bus by adopting the energy storage system, the method for controlling the voltage of the direct current bus by the wind driven generator set can reduce the construction cost of the direct current micro-grid, improve the stability of the voltage of the direct current bus and improve the response speed of controlling the voltage of the direct current bus.
Description
Technical Field
The application relates to the technical field of micro-grids, in particular to a method and a device for controlling direct-current bus voltage, a direct-current micro-grid system and a storage medium.
Background
From the control perspective of the direct current microgrid, the direct current bus voltage is the only index capable of measuring the power balance in the direct current microgrid system, and in the prior art, the direct current bus voltage is controlled, and the direct current bus voltage is generally stabilized by adopting an energy storage system. When the power generation power and the power utilization power of the direct-current micro-grid are not matched, the energy storage system absorbs or provides redundant power so as to keep the balance of the power and maintain the stable voltage of the bus.
However, this puts high demands on the energy storage system, and if it is necessary to ensure that the capacity of the energy storage system must be large enough and the charging and discharging speed of the energy storage system is high, the rate requirement of system regulation is met, and based on the demand on the energy storage system, the construction cost of the microgrid is increased.
When the capacity of the energy storage system is not enough to maintain the control requirement of the direct-current bus voltage, the energy storage system needs to perform charging and discharging for many times to stabilize the direct-current bus voltage, so that the control response of the direct-current bus voltage is not timely enough, and the service life of the direct-current bus voltage can be directly influenced by the charging and discharging for many times.
Disclosure of Invention
The invention aims to provide a method and a device for controlling a direct current bus voltage, a direct current micro-grid system and a storage medium, which can reduce the construction cost and improve the response speed of the direct current bus voltage control.
In order to achieve the above purpose, the embodiments of the present application employ the following technical solutions:
in a first aspect, an embodiment of the present application provides a method for controlling a dc bus voltage, which is applied to a dc microgrid system, where the dc microgrid system includes a wind turbine generator and a dc microgrid, the dc microgrid includes a photovoltaic power generation set and a load area, and the wind turbine generator and/or the photovoltaic power generation set are connected to the load area through a dc bus and supply power to the load area, and the method includes:
under the condition that the direct current microgrid is detected to have a load demand, incorporating the wind turbine generator into the direct current microgrid through an AC/DC converter, wherein the load demand indicates that the power of the photovoltaic generator set is smaller than the consumed power of the load area;
detecting the voltage of a direct current bus in real time, and determining whether the voltage of the direct current bus is increased or decreased;
under the condition that the voltage of the direct current bus is increased, adjusting a first parameter of the wind turbine generator so as to enable the voltage of the direct current bus to be reduced to a set interval;
and under the condition that the voltage of the direct current bus is reduced, adjusting a second parameter of the wind turbine generator so as to enable the voltage of the direct current bus to rise to a set interval.
In an optional embodiment, the wind turbine generator includes an impeller, the impeller includes a pitch system, and the step of adjusting a first parameter of the wind turbine generator to decrease the dc bus voltage to a set interval when the dc bus voltage is increased includes:
and under the condition that the voltage of the direct current bus is increased, sequentially reducing the torque of the wind turbine generator, controlling the variable pitch system to reduce the windward area of the blades and reducing the rotating speed of the impeller so as to reduce the voltage of the direct current bus to a set interval.
In an optional embodiment, the wind turbine generator includes an impeller, the impeller includes a variable pitch system, and the step of adjusting a second parameter of the wind turbine generator to raise the dc bus voltage to a steady state when the dc bus voltage decreases includes:
under the condition that the voltage of the direct current bus is reduced, the torque of the wind turbine generator is sequentially increased, the pitch control system is controlled to increase the windward area of the blades, the rotating speed of the impeller is increased, and first power is output to the direct current bus, so that the voltage of the direct current bus is increased to a set interval.
In an alternative embodiment, the method further comprises:
under the condition that the direct current micro-grid is detected to have no load demand, the wind turbine generator is merged into an alternating current grid through a DC/AC converter;
detecting whether the direct current micro-grid has a load demand in real time;
and under the condition that the load requirement of the direct current micro-grid is detected, disconnecting the wind turbine generator from the alternating current grid.
In an alternative embodiment, the dc microgrid system further comprises an energy storage system, and the method further comprises:
determining the actual generated active power of the wind turbine generator;
comparing the actual generated active power to the load demand;
judging whether the energy storage system needs to be charged or not under the condition that the actual generated active power is larger than the load demand;
and if so, carrying out charging operation on the energy storage system.
In an optional embodiment, after the step of adjusting the second parameter of the wind turbine generator to increase the dc bus voltage to the set interval when the dc bus voltage decreases, the method further includes:
detecting the adjusted first voltage of the direct current bus;
and calling the energy storage system to discharge the direct current bus under the condition that the first voltage does not belong to the set interval so as to enable the voltage of the direct current bus to rise to the set interval.
In a second aspect, the present application provides a method applied to a dc microgrid system, where the method includes:
the processing module is used for merging the wind generating set into the direct-current microgrid through an AC/DC converter under the condition that the direct-current microgrid is detected to have a load demand, wherein the load demand indicates that the power of the photovoltaic power generating set is smaller than the consumed power of a load area;
the detection module is used for detecting the voltage of the direct current bus in real time and determining whether the voltage of the direct current bus is increased or decreased;
the first adjusting module is used for adjusting a first parameter of the wind turbine generator set under the condition that the voltage of the direct current bus is increased so as to enable the voltage of the direct current bus to be reduced to a set interval;
and the second adjusting module is used for adjusting a second parameter of the wind turbine generator under the condition that the voltage of the direct current bus is reduced so as to enable the voltage of the direct current bus to rise to a set interval.
In a third aspect, an embodiment of the present application provides a dc microgrid system, which includes a memory and a processor, where the memory stores a computer program, and the processor implements the steps of the method for controlling the dc bus voltage when executing the computer program.
In a fourth aspect, the present application provides a storage medium, on which a computer program is stored, and the computer program, when executed by a processor, implements the steps of the method for controlling the dc bus voltage.
The application has the following beneficial effects:
according to the method, under the condition that the load requirement of the direct-current microgrid is detected, the wind turbine generator is merged into the direct-current microgrid through the AC/DC converter, wherein the load requirement indicates that the power of the photovoltaic power generation set is smaller than the consumed power of the direct-current microgrid; detecting the voltage of the direct-current bus in real time, and determining whether the voltage of the direct-current bus is increased or decreased; under the condition that the voltage of the direct current bus is increased, adjusting a first parameter of the wind turbine generator so as to enable the voltage of the direct current bus to be reduced to a set interval; and under the condition that the voltage of the direct current bus is reduced, adjusting a second parameter of the wind turbine generator so as to enable the voltage of the direct current bus to rise to a set interval. Compared with the traditional method for controlling the voltage stability of the direct current bus by adopting the energy storage system, the method for controlling the voltage of the direct current bus by the wind driven generator set can reduce the construction cost of the direct current microgrid, improve the stability of the voltage of the direct current bus and improve the response speed of controlling the voltage of the direct current bus.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.
Fig. 1 is a schematic block diagram of a dc microgrid system according to an embodiment of the present application;
fig. 2 is a flowchart illustrating steps of a method for controlling a dc bus voltage according to an embodiment of the present disclosure;
fig. 3 is a second flowchart illustrating steps of a method for controlling a dc bus voltage according to an embodiment of the present disclosure;
fig. 4 is a flowchart illustrating a third step of a method for controlling a dc bus voltage according to an embodiment of the present disclosure;
fig. 5 is a fourth flowchart illustrating steps of a method for controlling a dc bus voltage according to an embodiment of the present disclosure;
fig. 6 is a block diagram of a structure of a control device for dc bus voltage according to an embodiment of the present disclosure.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present application, as presented in the figures, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined or explained in subsequent figures.
Furthermore, the appearances of the terms "first," "second," and the like, if any, are only used to distinguish one description from another and are not to be construed as indicating or implying relative importance.
In the description of the present application, it is further noted that, unless expressly stated or limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.
Through a great deal of research by the inventor, it is found that, when the dc bus voltage is controlled in the prior art, the energy storage system is generally adopted to stabilize the dc bus voltage. When the power generation power and the power utilization power of the direct-current micro-grid are not matched, the energy storage system absorbs or provides redundant power so as to keep the balance of the power and maintain the stable voltage of the bus. However, to achieve the stability of the dc bus voltage based on the energy storage system, it is necessary to ensure that the energy storage system has a larger capacity and a higher charging and discharging speed, and in order to satisfy the above conditions, the construction cost needs to be increased in the control scheme for the dc bus. If the capacity of the energy storage system is not enough to maintain the stability of the system, the energy storage system needs to perform charging and discharging operations for multiple times, so that the service life of the energy storage system is shortened, and the direct current bus voltage cannot be stably controlled in time due to the multiple charging and discharging operations.
In view of the discovery of the above problems, the present embodiment provides a method and an apparatus for controlling a dc bus voltage, a dc microgrid system, and a storage medium, and compared with a conventional method for controlling the dc bus voltage stability by using an energy storage system, the present application provides a method for controlling a dc bus voltage by using a wind power generator set, which can reduce the construction cost of a dc microgrid, improve the stability of the dc bus voltage, and improve the response speed of controlling the dc bus voltage, and the following describes the scheme provided in this embodiment in detail.
The embodiment provides a direct current micro-grid system capable of controlling a direct current bus voltage. In one possible implementation, the dc microgrid system may be a wind power generation control system.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a dc microgrid system 100 according to an embodiment of the present application. The dc microgrid system 100 may also include more or fewer components than shown in fig. 1, or have a different configuration than that shown in fig. 1. The components shown in fig. 1 may be implemented in hardware, software, or a combination thereof.
The dc microgrid system 100 includes a dc bus voltage control device 110, a memory 120, and a processor 130.
The elements of the memory 120 and the processor 130 are electrically connected to each other directly or indirectly to achieve data transmission or interaction. For example, the components may be electrically connected to each other via one or more communication buses or signal lines. The control device 110 for the dc bus voltage includes at least one software functional module which can be stored in the memory 120 in the form of software or firmware (firmware) or solidified in an Operating System (OS) of the dc microgrid system 100. The processor 130 is used for executing executable modules stored in the memory 120, such as software functional modules and computer programs included in the control device 110 for controlling the dc bus voltage.
The Memory 120 may be, but is not limited to, a Random Access Memory (RAM), a Read Only Memory (ROM), a Programmable Read-Only Memory (PROM), an Erasable Read-Only Memory (EPROM), an electrically Erasable Read-Only Memory (EEPROM), and the like. The memory 120 is used for storing a program, and the processor 130 executes the program after receiving the execution instruction.
Referring to fig. 2, fig. 2 is a flowchart illustrating a method for controlling a dc bus voltage applied to the dc microgrid system 100 of fig. 1, and the method includes various steps as described in detail below.
The method is applied to a direct-current micro-grid system, the direct-current micro-grid system comprises a wind turbine generator and a direct-current micro-grid, the direct-current micro-grid comprises a photovoltaic power generation set and a load area, and the wind turbine generator and/or the photovoltaic power generation set are/is connected with the load area through a direct-current bus and supply power to the load area.
When the load demand exists in the direct current microgrid, the wind turbine generator set can be incorporated into the direct current microgrid, when the load demand does not exist in the direct current microgrid, the wind turbine generator set is electrically connected with the direct current microgrid in a disconnection mode, and at the moment, the photovoltaic power generation set supplies power for a load area of the direct current microgrid.
Step 201: and under the condition that the load requirement of the direct current microgrid is detected, the wind turbine generator is merged into the direct current microgrid through the AC/DC converter.
Wherein the load demand indicates that the power of the photovoltaic power generation group is less than the consumed power of the load zone.
And a data processing component in the direct current micro-grid system determines whether the direct current micro-grid has a load demand in real time, wherein the load demand is that the generated power of the current photovoltaic power generation set cannot meet the power to be consumed by a load area in the direct current micro-grid.
The photovoltaic power generation is based on the principle of photovoltaic effect, and solar energy is directly converted into electric energy by using a solar cell.
For example: when present sunshine is poor, the photovoltaic power generation set can not be based on converting sufficient light energy into electric energy, and the power that the direct current microgrid needs to consume is greater than the power of photovoltaic power generation set output this moment, and the sign direct current microgrid has the load demand this moment. When sunlight is sufficient, the photovoltaic power generation set can convert enough light energy into electric energy, the electric energy generated by the photovoltaic power generation set is enough to support the power to be consumed in a load area, and at the moment, the representation direct-current micro-grid has no load demand.
Step 202: and detecting the voltage of the direct current bus in real time, and determining whether the voltage of the direct current bus is increased or decreased.
In the little electric wire netting of transformer substation direct current that drops into, the frequent fluctuation of direct current bus voltage when fluctuation range is great, can lead to fault filter frequently to start, causes hidden danger to little electric wire netting powered device of direct current simultaneously, if: may cause accidents such as malfunction of the protection outlet relay.
Therefore, the direct current bus voltage is detected in real time, and whether the current direct current bus voltage is in a set interval or not is judged, wherein the set interval indicates that the direct current bus voltage is in a normal voltage interval.
And determining whether the current direct-current bus voltage is lower than the lowest value or higher than the highest value of the set interval based on the set interval, determining that the direct-current bus voltage is reduced when the direct-current bus voltage is lower than the lowest value of the set interval, and determining that the direct-current bus voltage is increased when the direct-current bus voltage is higher than the highest value of the set interval.
Based on the condition that the voltage of the direct current bus rises or falls, the wind turbine generator is called to regulate and control the voltage of the direct current bus, so that the voltage of the direct current bus is stabilized in a set interval.
Step 203: and under the condition that the voltage of the direct current bus is increased, adjusting a first parameter of the wind turbine generator so as to enable the voltage of the direct current bus to be reduced to a set interval.
The wind turbine generator system includes the impeller, and the impeller contains becomes oar system, and to the first parameter of how to adjust the wind turbine generator system, the mode that reduces direct current busbar voltage can be for:
under the condition that the voltage of the direct current bus is increased, the torque of the wind turbine generator is sequentially reduced, the pitch control system is controlled to reduce the windward area of the blades, and the rotating speed of the impeller is reduced, so that the voltage of the direct current bus is reduced to a set interval.
The wind turbine generator set firstly adopts a torque control mode, namely, the torque of the wind turbine generator set is reduced, so that the voltage of a direct current bus is prevented from rising rapidly, at the moment, the response time of the wind turbine generator set is in a millisecond level, then a variable pitch system is controlled to reduce the windward area of blades, the rotating speed of an impeller is reduced, the active output of the wind turbine generator set is limited, the voltage of the direct current bus is kept falling to a set interval, and the voltage of the direct current bus is kept in a stable state. The wind turbine generator realizes the functions through the double PI controllers.
Step 204: and under the condition that the voltage of the direct current bus is reduced, adjusting a second parameter of the wind turbine generator so as to enable the voltage of the direct current bus to rise to a set interval.
Under the condition that the load requirement of the direct current microgrid is detected, the wind turbine generator is merged into the direct current microgrid, and the wind turbine generator is reserved with power regulation capacity, namely, when the wind turbine generator is merged into the direct current microgrid, the wind turbine generator does not operate in a maximum active power output mode, but part of active power regulation capacity is reserved, namely, the reserved part of active power is the first power.
At the moment, when the voltage of the direct current bus is reduced, the torque of the wind turbine generator is sequentially increased, the variable pitch system is controlled to increase the windward area of the blades, the rotating speed of the impeller is increased, and first power is output to the direct current bus, so that the voltage of the direct current bus is increased to a set interval. The reserved active power, i.e. the first power, can be adjusted when the dc bus voltage is reduced.
It should be noted that the reserved first power is set according to the relevant ratio of the active power supplied by the system to the active power required by the system, and the specific value of the first power is not specifically limited in the present application.
Based on the fact that the torque of the wind turbine generator is increased, the pitch control system is controlled to increase the windward area of the blades, the rotating speed of the impeller is increased, and the first power is output to the direct current bus, the response to the voltage control of the direct current bus can be improved, and the response time is about 500 ms.
According to the method, under the condition that the load requirement of the direct-current microgrid is detected, the wind turbine generator is merged into the direct-current microgrid through the AC/DC converter, wherein the load requirement indicates that the power of the photovoltaic power generation set is smaller than the consumed power of the direct-current microgrid; detecting the voltage of the direct-current bus in real time, and determining whether the voltage of the direct-current bus is increased or decreased; under the condition that the voltage of the direct current bus is increased, adjusting a first parameter of the wind turbine generator so as to enable the voltage of the direct current bus to be reduced to a set interval; and under the condition that the voltage of the direct current bus is reduced, adjusting a second parameter of the wind turbine generator so as to enable the voltage of the direct current bus to rise to a set interval. Compared with the traditional method for controlling the voltage stability of the direct current bus by adopting the energy storage system, the method for controlling the voltage of the direct current bus by the wind driven generator set can reduce the construction cost of the direct current microgrid, improve the stability of the voltage of the direct current bus and improve the response speed of controlling the voltage of the direct current bus.
In another embodiment of the present application, as shown in fig. 3, a method for controlling a dc bus voltage is provided, which specifically includes the following steps:
step 301: and under the condition that the direct current micro-grid is detected to have no load demand, the wind turbine generator is merged into the alternating current grid through the DC/AC converter.
Step 302: and detecting whether the load demand exists in the direct current micro-grid or not in real time.
Step 303: and under the condition that the load requirement of the direct current micro-grid is detected, disconnecting the wind turbine generator from the alternating current grid.
And under the condition that the direct-current micro-grid is detected to have no load demand, the generated power is sent to the alternating-current power grid through the DC/AC grid-connected converter, and the benefit of the micro-grid station is increased.
The alternating current power grid is a current national power grid and comprises a power plant, a transformer substation, a transmission line network, a distribution transformer and a low-voltage line network.
When the wind turbine generator is merged into the alternating current power grid to generate electricity, whether a load request exists in the direct current micro power grid is detected, when the load request exists in the direct current micro power grid, the connection between the wind turbine generator and the alternating current power grid is disconnected, the wind turbine generator is merged into the direct current micro power grid, and power is supplied to a load area in the direct current micro power grid.
In another embodiment of the present application, as shown in fig. 4, a method for controlling a dc bus voltage is provided, which specifically includes the following steps:
step 401: and determining the actual generated active power of the wind turbine generator.
Step 402: the actual generated active power is compared to the load demand.
Step 403: and under the condition that the actual active power is greater than the load demand, judging whether the energy storage system needs to be charged.
Step 404: and if so, performing charging operation on the energy storage system.
The method comprises the steps of determining the actual active power generated by the wind turbine generator, comparing the actual active power generated by the wind turbine generator with a load demand, indicating that the actual active power generated by the current wind turbine generator is surplus when the actual active power generated by the wind turbine generator is larger than the load demand, judging whether the energy storage system needs to be charged when the actual active power generated by the current wind turbine generator is surplus, charging the energy storage system if the energy storage system needs to be charged, and meeting the load demand of the direct-current microgrid.
The energy storage system of the direct-current microgrid system is charged, so that the direct-current bus voltage can be guaranteed to be raised by outputting power to the direct-current bus through the energy storage system when the direct-current bus voltage is reduced in the follow-up process.
When the voltage of the direct current bus is increased, the energy storage system can absorb redundant power, so that the voltage of the direct current bus is reduced, and the voltage of the direct current bus can be maintained in a set interval.
In another embodiment of the present application, as shown in fig. 5, a method for controlling a dc bus voltage is provided, which specifically includes the following steps:
step 501: and detecting the adjusted first voltage of the direct current bus.
Step 502: and under the condition that the first voltage does not belong to the set interval, calling the energy storage system to discharge the direct current bus so as to enable the voltage of the direct current bus to rise to the set interval.
Supplementary input of an energy storage system: if the load demand is increased, the active power reserved by the wind turbine generator, namely the first power output by the wind turbine generator, the torque of the wind turbine generator, the windward area of the blades and the rotating speed of the impeller are increased by controlling the pitch control system, the first voltage of the direct-current bus is detected and is not raised to a set interval, then the energy storage system is used as supplement input at the moment, and the bus voltage is maintained to be stable through the discharge of the backup power supply.
Referring to fig. 6, the present embodiment further provides a control device 110 for a dc bus voltage applied to the dc microgrid system 100 shown in fig. 1, where the control device 110 for the dc bus voltage includes:
the processing module 111 is configured to, when it is detected that a load demand exists in the direct-current microgrid, incorporate a wind turbine generator into the direct-current microgrid through an AC/DC converter, where the load demand indicates that power of the photovoltaic generator is less than consumed power of a load zone;
the detection module 112 is configured to detect a dc bus voltage in real time, and determine whether the dc bus voltage increases or decreases;
the first adjusting module 113 is configured to adjust a first parameter of the wind turbine generator when the dc bus voltage increases, so that the dc bus voltage decreases to a set interval;
and a second adjusting module 114, configured to adjust a second parameter of the wind turbine generator under the condition that the dc bus voltage is reduced, so that the dc bus voltage is increased to a set interval.
Preferably, the first adjusting module 113 is specifically configured to: and under the condition that the voltage of the direct current bus is increased, sequentially reducing the torque of the wind turbine generator, controlling the variable pitch system to reduce the windward area of the blades and reducing the rotating speed of the impeller so as to reduce the voltage of the direct current bus to a set interval.
The present application further provides a dc microgrid system 100, wherein the dc microgrid system 100 includes a processor 130 and a memory 120. The memory 120 stores computer-executable instructions that, when executed by the processor 130, implement the method for controlling the dc bus voltage.
The embodiment of the present application further provides a storage medium, where the storage medium stores a computer program, and when the computer program is executed by the processor 130, the method for controlling the dc bus voltage is implemented.
In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. The apparatus embodiments described above are merely illustrative and, for example, the flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
In addition, functional modules in the embodiments of the present application may be integrated together to form an independent part, or each module may exist alone, or two or more modules may be integrated to form an independent part. The functions, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
It should be noted that, in this document, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in the process, method, article, or apparatus that comprises the element.
The above description is only for various embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (10)
1. A control method of direct current bus voltage is applied to a direct current micro-grid system, the direct current micro-grid system comprises a wind turbine generator and a direct current micro-grid, the direct current micro-grid comprises a photovoltaic power generation set and a load area, the wind turbine generator and/or the photovoltaic power generation set are/is connected with the load area through a direct current bus and supply power to the load area, and the method is characterized by comprising the following steps:
incorporating the wind turbine into the direct current microgrid via an AC/DC converter upon detecting a load demand on the direct current microgrid, wherein the load demand indicates that power of the photovoltaic power generation group is less than power consumed by the load zone;
detecting the voltage of a direct current bus in real time, and determining whether the voltage of the direct current bus is increased or decreased;
under the condition that the voltage of the direct current bus is increased, adjusting a first parameter of the wind turbine generator so as to enable the voltage of the direct current bus to be reduced to a set interval;
and under the condition that the voltage of the direct current bus is reduced, adjusting a second parameter of the wind turbine generator so as to enable the voltage of the direct current bus to rise to a set interval.
2. The method according to claim 1, wherein the wind turbine generator comprises an impeller including a pitch system, and the step of adjusting a first parameter of the wind turbine generator to decrease the dc bus voltage to a set interval when the dc bus voltage is increased comprises:
and under the condition that the voltage of the direct current bus is increased, sequentially reducing the torque of the wind turbine generator, controlling the variable pitch system to reduce the windward area of the blades and reducing the rotating speed of the impeller so as to reduce the voltage of the direct current bus to a set interval.
3. The method of claim 1, wherein the wind turbine includes an impeller including a pitch system, and wherein the step of adjusting a second parameter of the wind turbine to raise the dc bus voltage to a steady state in the event of a decrease in the dc bus voltage comprises:
under the condition that the voltage of the direct current bus is reduced, sequentially increasing the torque of the wind turbine generator, controlling the variable pitch system to increase the windward area of blades, increasing the rotating speed of the impeller and outputting first power to the direct current bus so as to enable the voltage of the direct current bus to rise to a set interval.
4. The method of claim 1, further comprising:
under the condition that the direct current microgrid is detected to have no load demand, the wind turbine generator is merged into an alternating current power grid through a DC/AC converter;
detecting whether the direct current micro-grid has a load demand in real time;
and under the condition that the load requirement of the direct current micro-grid is detected, disconnecting the wind turbine generator from the alternating current grid.
5. The method of claim 1, wherein the direct current microgrid system further comprises an energy storage system, the method further comprising:
determining the actual generated active power of the wind turbine generator;
comparing the actual generated active power to the load demand;
judging whether the energy storage system needs to be charged or not under the condition that the actual generated active power is larger than the load demand;
and if so, performing charging operation on the energy storage system.
6. The method of claim 5, wherein after the step of adjusting the second parameter of the wind turbine to increase the DC bus voltage to a set interval in the event of a decrease in the DC bus voltage, the method further comprises:
detecting the adjusted first voltage of the direct current bus;
and calling the energy storage system to discharge the direct current bus under the condition that the first voltage does not belong to the set interval so as to enable the voltage of the direct current bus to rise to the set interval.
7. A device for controlling dc bus voltage, the device comprising:
the processing module is used for merging the wind turbine generator into the direct-current microgrid through an AC/DC converter under the condition that the direct-current microgrid has a load demand, wherein the load demand indicates that the power of the photovoltaic generator set is smaller than the consumed power of a load area;
the detection module is used for detecting the voltage of the direct current bus in real time and determining whether the voltage of the direct current bus is increased or decreased;
the first adjusting module is used for adjusting a first parameter of the wind turbine generator set under the condition that the voltage of the direct current bus is increased so as to enable the voltage of the direct current bus to be reduced to a set interval;
and the second adjusting module is used for adjusting a second parameter of the wind turbine generator under the condition that the voltage of the direct current bus is reduced so as to enable the voltage of the direct current bus to rise to a set interval.
8. The device of claim 7, wherein the wind turbine comprises an impeller including a pitch system, and the first adjustment module is specifically configured to: and under the condition that the voltage of the direct current bus is increased, sequentially reducing the torque of the wind turbine generator, controlling the variable pitch system to reduce the windward area of the blades and reducing the rotating speed of the impeller so as to reduce the voltage of the direct current bus to a set interval.
9. A dc microgrid system comprising a memory and a processor, said memory storing a computer program, characterized in that said processor implements the steps of the method according to any of claims 1-6 when executing said computer program.
10. A storage medium having a computer program stored thereon, the computer program, when being executed by a processor, performing the steps of the method as set forth in any one of the claims 1-6.
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