CN117318009A - Dynamic partitioning method and system for power distribution network containing embedded direct current - Google Patents
Dynamic partitioning method and system for power distribution network containing embedded direct current Download PDFInfo
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- 230000002457 bidirectional effect Effects 0.000 claims description 5
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Classifications
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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
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
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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
- H02J3/007—Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources
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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
- H02J3/007—Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources
- H02J3/0073—Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources for providing alternative feeding paths between load and source when the main path fails, e.g. transformers, busbars
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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
- H02J3/04—Circuit arrangements for ac mains or ac distribution networks for connecting networks of the same frequency but supplied from different sources
- H02J3/06—Controlling transfer of power between connected networks; Controlling sharing of load between connected networks
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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
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
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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
- H02J4/00—Circuit arrangements for mains or distribution networks not specified as ac or dc
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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
- H02J5/00—Circuit arrangements for transfer of electric power between ac networks and dc networks
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The invention discloses a dynamic partitioning method of a power distribution network containing embedded direct current, which comprises the steps of embedding a multi-terminal direct current power distribution network which is in a disconnection state at ordinary times; the voltage and the electric quantity of current of a feeder line are actively regulated through an AC/DC converter of AC/DC interconnection equipment, so that near-zero current disconnection and active synchronous closing of a feeder line switch are realized; and the AC/DC converter is utilized for flexibly adjusting and actively synchronizing the power flow, so that dynamic partition power supply among different areas is realized. The method can eliminate switching loss, and solves the problems that the interconnection switch cannot be frequently switched, the interconnection of a plurality of feeder lines can not meet the requirement of real-time power support by using the interconnection switch, and the safety operation requirement of a power distribution network is difficult to meet when the problems of overload power supply and unbalanced load are met.
Description
Technical Field
The invention relates to the field of dynamic partitioning of power distribution networks, in particular to an AC/DC converter utilizing an embedded direct current system for actively carrying out dynamic partitioning power supply on an overload area.
Background
In recent years, with the continuous expansion of the scale of the power system and the gradual increase of the power quality requirement at the demand side, the defects of the traditional power supply mode are gradually revealed, and the problems of overload power supply, unbalanced load, reduced reliability and the like exist. When the tie switch is directly used for switching, temporary overvoltage can be generated at the feeder switch, the stability and the reliability of a system are threatened, the service lives of sensitive loads are easily influenced and even damaged, and the abrasion cost of the switch equipment is increased. Meanwhile, as the interconnection switch cannot be frequently switched, the interconnection of a plurality of feeder lines is realized by using the interconnection switch, and the requirement of power real-time support cannot be met obviously. On the other hand, compared with the traditional power distribution network, the power distribution network has a plurality of devices controlled by the power distribution network, flows bidirectionally, is not easy to perform scheduling control, divides the power distribution network into a plurality of subareas with strong internal electrical connection and weak inter-subarea connection, and is beneficial to scheduling control in the subareas, but when the problems of overload power supply and unbalanced load are encountered, the safety operation requirement of the power distribution network is difficult to meet.
Disclosure of Invention
This section is intended to outline some aspects of embodiments of the invention and to briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section as well as in the description summary and in the title of the application, to avoid obscuring the purpose of this section, the description summary and the title of the invention, which should not be used to limit the scope of the invention.
The present invention has been made in view of the above-described problems occurring in the prior art.
Therefore, the invention provides a dynamic partitioning method for a power distribution network with embedded direct current, which can solve the problem that the traditional free surface related multiple suppression method cannot adapt to seismic data acquired in a submarine node observation mode.
In order to solve the technical problems, the invention provides the following technical scheme, namely a dynamic partitioning method for a power distribution network containing embedded direct current, which comprises the following steps:
embedding a multi-terminal direct current distribution network which is in a disconnection state at ordinary times;
the voltage and the electric quantity of current of a feeder line are actively regulated through an AC/DC converter of AC/DC interconnection equipment, so that near-zero current disconnection and active synchronous closing of a feeder line switch are realized;
and the AC/DC converter is utilized for flexibly adjusting and actively synchronizing the power flow, so that dynamic partition power supply among different areas is realized.
As a preferable scheme of the power distribution network dynamic partitioning method containing embedded direct current, the invention comprises the following steps: the multi-terminal direct current distribution network comprises an AC/DC converter of an AC/DC interconnection device in an embedded direct current link to actively regulate the electric quantity of power, voltage and current of a feeder line to be transferred, so as to realize near-zero current disconnection and active synchronous closing of a feeder line switch.
As a preferable scheme of the power distribution network dynamic partitioning method containing embedded direct current, the invention comprises the following steps: the AC/DC converter comprises a 10kV feeder line of each alternating-current end, the 10kV feeder line of each alternating-current end is connected with the bidirectional AC/DC converter and is connected with the bidirectional AC/DC converter through a shared medium-voltage direct-current bus, and the AC/DC converter adopts a modularized converter, a two-level converter and a three-level converter.
As a preferable scheme of the power distribution network dynamic partitioning method containing embedded direct current, the invention comprises the following steps: the method comprises the steps that the AC/DC converter actively adjusts the voltage and the electric quantity of the current of a feeder line, namely, the active power and the reactive power of a feeder line switch are continuously adjusted by changing the control mode of the AC/DC converter in an embedded direct current network, when the active power and the reactive power are zero, the current flowing through the feeder line switch is zero, the voltage difference between two ends of a contact switch is also zero, and a temporary overvoltage can be ignored when the switch is disconnected;
after the voltage synthesis, the controller of the converter is connected with the voltage amplitude output by the inner loop and the phase value output by the phase-locked loop into PWM for modulation.
As a preferable scheme of the power distribution network dynamic partitioning method containing embedded direct current, the invention comprises the following steps: the near-zero current disconnection comprises the steps of changing the control mode of the AC/DC converter at the overload area side into VSG control VF control when the load unbalance and partial load overload phenomenon occur in the power supply area, actively regulating the power flowing through the feeder switch, and enabling the current flowing through the feeder switch to be zero when the active power and the reactive power are zero, so that the zero current disconnection is completed.
As a preferable scheme of the power distribution network dynamic partitioning method containing embedded direct current, the invention comprises the following steps: the active synchronous closing comprises the steps of actively adjusting the voltage amplitude and the phase of a contact switch by utilizing VSG control of an AC/DC converter of an embedded direct current system, and closing the switch when the voltage deviation of two ends of the switch is minimum, so as to realize active synchronous closing.
As a preferable scheme of the power distribution network dynamic partitioning method containing embedded direct current, the invention comprises the following steps: the dynamic partitioning comprises the steps of utilizing an AC/DC converter of an embedded direct current system to adjust the power, voltage and current of a switch, dividing a load from an overload area to a power supply area, and realizing dynamic area division and uninterrupted power action of the dynamic division area of a power distribution network
The invention further aims to provide a grid frame periodic intelligent diagnosis analysis system of the distribution network online system, which can actively carry out dynamic partition power supply on an overload area through an AC/DC converter and solve the problems of power supply overload, unbalanced load, reduced reliability and the like.
The system of the dynamic partitioning method of the power distribution network with the embedded direct current is characterized by comprising an embedded direct current inverter, a direct current bus, an AC/DC converter, a dynamic partitioning controller and a direct current load;
the embedded direct current inverter converts alternating current into direct current and embeds the direct current into a power grid;
the direct current buses are used for receiving direct current from each embedded direct current inverter and transmitting the direct current to different direct current loads, and filtering and voltage stabilization are carried out through elements such as a capacitor and an inductor;
the AC/DC converter actively adjusts the electric quantity of power, voltage and current of a feeder line to be transferred, and realizes near-zero current disconnection and active synchronous closing of a feeder line switch;
the dynamic partition controller dynamically partitions the power distribution network based on the data monitored in real time, and adjusts the output power of the direct current bus and the partition scheme according to the requirement;
the DC load obtains the required DC from the DC bus, reduces the loss and cost of energy conversion
A computer device comprising a memory and a processor, said memory storing a computer program, characterized in that said processor, when executing said computer program, implements the steps of a method according to the method for dynamic partitioning of a power distribution network comprising embedded direct current.
A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of a method for dynamic partitioning of a power distribution network comprising embedded direct current
The invention has the beneficial effects that: the embedded structure adopted by the method is a multi-terminal direct current distribution network, and each alternating current terminal 10kV feeder line is connected with a bidirectional AC/DC converter and is connected with a common medium-voltage direct current bus. If overload and other phenomena occur on a certain feeder line in the power supply area, the voltage and the electric quantity of the current of the feeder line can be actively regulated through an AC/DC converter of the AC/DC interconnection equipment, and the switch is disconnected when the voltage is near zero, so that the uninterrupted operation of the feeder line switch is realized, the switching loss is greatly reduced and even eliminated, and the automatic matching of SOP and the distribution network is realized. Meanwhile, in order to ensure normal power supply of a fault area, the AC/DC converter is utilized to flexibly adjust and actively synchronize power flow, the fault area is divided into other normal power supply areas, dynamic partition power supply among different areas is realized, and the power supply reliability and stability of the system are improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, 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. Wherein:
fig. 1 is a flowchart of a dynamic partitioning method for a power distribution network with embedded dc according to an embodiment of the present invention.
Fig. 2 is a schematic diagram of embodiment 1 of a dynamic partitioning method for a power distribution network including embedded dc according to an embodiment of the present invention.
Fig. 3 is a schematic diagram illustrating a dynamic area division required by a power supply area II of a dynamic partitioning method for a power distribution network including embedded dc according to an embodiment of the present invention.
Fig. 4 is a schematic diagram of VSG control adopted on the converter 2 side of a power distribution network dynamic partitioning method with embedded dc according to an embodiment of the present invention.
Fig. 5 is a U adopted on the converter 1 side of a power distribution network dynamic partitioning method with embedded dc according to an embodiment of the present invention dc Q control schematic.
Fig. 6 is a schematic diagram of an S3 near zero current disconnection dual-loop controller of a power distribution network dynamic partitioning method with embedded dc according to an embodiment of the present invention.
Fig. 7 is a schematic diagram of controlling a bus side of a power supply area II when TS1 of a dynamic partitioning method of a power distribution network with embedded dc is synchronously switched on according to an embodiment of the present invention.
Fig. 8 is a schematic diagram of controlling a bus side of a power supply area I when TS1 of a dynamic partitioning method of a power distribution network with embedded dc is synchronously switched on according to an embodiment of the present invention.
Fig. 9 is a flowchart of a dynamic partitioning-to-power method of a dynamic partitioning method of a power distribution network with embedded dc according to an embodiment of the present invention.
Fig. 10 is a schematic diagram of embodiment 2 of a dynamic partitioning method for a power distribution network with embedded dc according to an embodiment of the present invention.
Fig. 11 is a schematic diagram illustrating a dynamic area division required by a power supply area II of a power distribution network dynamic partitioning method including embedded dc according to an embodiment of the present invention.
Fig. 12 is a schematic diagram of PQ control adopted on the inverter 3 side of a power distribution network dynamic partitioning method with embedded dc according to an embodiment of the present invention.
Fig. 13 is a flowchart of a dynamic partitioning-to-power method of a dynamic partitioning method of a power distribution network with embedded dc according to an embodiment of the present invention.
Fig. 14 is a flowchart of a dynamic partitioning system for a power distribution network with embedded dc according to an embodiment of the present invention.
Detailed Description
So that the manner in which the above recited objects, features and advantages of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments, some of which are illustrated in the appended drawings. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways other than those described herein, and persons skilled in the art will readily appreciate that the present invention is not limited to the specific embodiments disclosed below.
Further, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic can be included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
While the embodiments of the present invention have been illustrated and described in detail in the drawings, the cross-sectional view of the device structure is not to scale in the general sense for ease of illustration, and the drawings are merely exemplary and should not be construed as limiting the scope of the invention. In addition, the three-dimensional dimensions of length, width and depth should be included in actual fabrication.
Also in the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper, lower, inner and outer", etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first, second, or third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
The terms "mounted, connected, and coupled" should be construed broadly in this disclosure unless otherwise specifically indicated and defined, such as: can be fixed connection, detachable connection or integral connection; it may also be a mechanical connection, an electrical connection, or a direct connection, or may be indirectly connected through an intermediate medium, or may be a communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
Example 1
Referring to fig. 1-9, a first embodiment of the present invention provides a dynamic partitioning method for a power distribution network including embedded dc, including:
s1: a multi-terminal DC power distribution network is embedded which is in a normally-off state.
Furthermore, the multi-terminal direct current distribution network comprises an AC/DC converter of an AC/DC interconnection device in an embedded direct current link to actively regulate the power and the electric quantity of voltage and current of a feeder line to be transferred, so as to realize near-zero current disconnection and active synchronous closing of a feeder line switch. FIG. 2 is a schematic diagram of embodiment 1 of the present invention, and the dynamic dividing regions are shown in the figure;
further, in fig. 3, the power supply area II in embodiment 1 of the present invention requires a dynamic area division schematic. When the power supply area II needs to be subjected to dynamic partition power supply, an embedded direct current network is accessed, the control strategy of the converter 2 is changed into VSG control, and a control block diagram is shown in fig. 5;
s2: the voltage and the electric quantity of the current of the feeder line are actively regulated through the AC/DC converter of the AC/DC interconnection equipment, so that near-zero current disconnection and active synchronous closing of the feeder line switch are realized.
It should be noted that the AC/DC converter comprises, for each AC end, a 10kV feeder connected to the bi-directional AC/DC converter and connected by a common medium voltage DC bus. The AC/DC converter may employ a modular converter (MMC) or a two-level converter or a three-level converter;
further, the active adjustment of the voltage and the electric quantity of the current of the feeder line by the AC/DC converter comprises the steps of continuously adjusting the active power and the reactive power of the feeder line switch by changing the control mode of the AC/DC converter in the embedded direct current network, when the active power and the reactive power are close to zero, the current flowing through the feeder line switch is close to zero, the voltage difference between two ends of the interconnecting switch is also close to zero, and the temporary overvoltage can be ignored by switching off the switch at the moment, so that the switching loss is greatly reduced or even eliminated;
furthermore, the near-zero current disconnection comprises that if the phenomena of unbalanced load, overload of partial load and the like occur in a power supply area, the control mode of the AC/DC converter at the overload area side can be changed into VSG control or VF control to actively regulate the power flowing through the feeder switch, and the current flowing through the feeder switch can be close to zero when the active power and the reactive power are close to zero, so that the zero current disconnection is completed;
further, as can be seen from fig. 4, in order to realize zero current break, the voltage V at the side of the signal collector S3 close to the converter 2 is collected S3 And current I S3 In order to enable the current I flowing through the switch S3 S3 Zero, the reference power P of VSG control can be directly set ref 、Q ref Zero, and then the amplitude U of the voltage reference value is obtained through VSG control ref And phase q;
it should be further noted that fig. 6 is a schematic diagram of a control manner adopted by the dual-loop controller at this time, after the voltage is synthesized, the dual-loop controller switches in the voltage amplitude outputted by the inner loop and the phase value outputted by the phase-locked loop to PWM for modulation;
further, by continually repeating the process such that the power and voltage difference across switch S3 is nearly zero, the current is also nearly zero, at which time turning off the switch will greatly reduce or even eliminate switching losses. After the switch S3 is disconnected, the load of the overload area is continuously supplied by the converter 2, and the residual load of the power supply area II is continuously supplied by the feeder line 2;
furthermore, in order to realize that the power supply area I supplies power to the overload area, active synchronous closing is required. As shown in fig. 7, the signal collector collects the voltage amplitude V of the switch TS1 near the power supply area II 12 And phase value delta 12 Then the amplitude and the phase U of the voltage reference value are obtained through VSG control ref Q, through voltage synthesis, input to the double-loop control, the double-loop controller adopts the control mode shown in figure 5 at this moment, then the double-loop controller is connected with PWM modulation, and the PWM modulation is modulated into on-off signals for controlling the switching device so as to control V 12 And delta 12 。
It should be noted that the same applies to FIG. 8, but the signal collector collects the voltage amplitude V of the switch TS1 near the power supply area II 11 And phase value delta 11 And the input reference value of the VSG control is V 12 、δ 12 The purpose is to actively regulate the voltage deviation across the switch TS1 by this control. And when the voltage deviation at the two ends of the TS1 is minimum, the switch is closed, and active synchronous closing is realized. After the switch TS1 is closed, the power supply area I continues to supply power to the overload area, so that the uninterrupted power supply transfer process of the area is realized.
S3: and the AC/DC converter is utilized for flexibly adjusting and actively synchronizing the power flow, so that dynamic partition power supply among different areas is realized.
Furthermore, the dynamic partitioning comprises the steps of utilizing an AC/DC converter of an embedded direct current system to adjust the power, voltage, current and the like of a switch, so that a load is partitioned from an overload area to other areas, thereby realizing the dynamic area partition of a power distribution network and realizing the uninterrupted operation of the dynamic partition area.
Example 2
Referring to fig. 10-13, for one embodiment of the present invention, a dynamic partitioning method for a power distribution network with embedded dc is provided, and in order to verify the beneficial effects of the present invention, scientific demonstration is performed through experiments.
Fig. 10 is a schematic diagram of embodiment 2 of the present invention, compared with embodiment 1, only the dynamic division area is different, and the method still adopts an AC/DC converter of an AC/DC interconnection device in an embedded DC link to actively regulate the power, voltage and current electrical quantity of a feeder line to be transferred, so as to realize near zero current disconnection and active synchronous closing of the feeder line switch.
Fig. 11 is a schematic diagram illustrating the dynamic area division required for the power supply area II in embodiment 2 of the present invention. In order to realize the power transfer process of the overload region, the overload region is divided into a dynamic division region 1 and a dynamic division region 2, and the operation is performed based on the control manner of the on-off switch adopted in embodiment 1. In case of overload in the supply area II, as shown in fig. 5, the converter 1 adopts U dc In the Q control mode, as shown in fig. 4, the inverter 2 adopts the VSG control mode, as shown in fig. 12, and the inverter 3 adopts the PQ control mode to control the power flowing through the switch S5 by the inverter 2 so that the current I S5 When the power supply is close to zero, the current converter 2 supplies power to the whole overload region, and the residual load of the power supply region II is continuously supplied by the feeder line 2; the VSG control of the converter 2 is used for controlling the voltage amplitude and the phase of the two ends of the switch TS1, and the switch is closed when the voltage difference of the two ends of the TS1 is minimum, and the whole overload area is powered by the power supply area I; then the current converter 2 is used for disconnecting the switch S1, at the moment, the power supply area I supplies power to the dynamic dividing area 1, and the current converter 2 supplies power to the dynamic dividing area 2; and finally, closing TS2 by using the converter 2, and supplying power to the dynamic dividing region 2 by the power supply region III, wherein the power supply region I continues to supply power to the dynamic dividing region 1, so that the uninterrupted power supply transfer process of the overload region is completed.
Fig. 13 is a control flow chart of a dynamic partitioning method for converting power to an overload area through a converter 2 based on an embedded dc power distribution network in this embodiment, which includes the following steps:
step 1: when overload fault occurs in the power supply area II, the embedded direct current network is accessed;
step 2: switching the control strategy of the converter 2 to VSG control, the control strategy of the converter 1 to PQ control;
step 3: with the inverter 2, the power flowing through the feeder switch S5 is controlled such that the current I flowing through S5 S5 Close to zero, disconnect S5;
step 4: when U, the voltage amplitude and the phase of the two ends of the tie switch TS1 are regulated by the current converter 2 11 And U 12 When the deviation of (1) is minimum, closing TS1;
step 5: with the inverter 2, the power flowing through the feeder switch S1 is controlled such that the current I flowing through S1 S1 Close to zero, disconnect S1;
step 6: regulating the voltage amplitude and phase of the two ends of the tie switch TS2 by using the converter 2, when U 21 And U 22 When the deviation of (2) is minimum, closing TS2;
step 7: the power supply area I supplies power to the dynamic dividing area 1, the power supply area III supplies power to the dynamic dividing area 2, and the power supply transferring process is completed.
It should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made thereto without departing from the spirit and scope of the technical solution of the present invention, which is intended to be covered by the scope of the claims of the present invention.
Example 3
A third embodiment of the present invention, which is different from the first two embodiments, is:
the functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-only memory (ROM), a random access memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.
Logic and/or steps represented in the flowcharts or otherwise described herein, e.g., a ordered listing of executable instructions for implementing logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.
More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). In addition, the computer readable medium may even be paper or other suitable medium on which the program is printed, as the program may be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory.
It is to be understood that portions of the present invention may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, the various steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, may be implemented using any one or combination of the following techniques, as is well known in the art: discrete logic circuits having logic gates for implementing logic functions on data signals, application specific integrated circuits having suitable combinational logic gates, programmable Gate Arrays (PGAs), field Programmable Gate Arrays (FPGAs), and the like.
Example 4
Referring to fig. 14, in one embodiment of the present invention, a system for dynamic partitioning of a power distribution network with embedded DC is provided, wherein an embedded DC inverter, a DC bus, an AC/DC converter, a dynamic partitioning controller, and a DC load;
the embedded direct current inverter converts alternating current into direct current and embeds the direct current into a power grid;
the direct current buses are used for receiving direct current from each embedded direct current inverter and transmitting the direct current to different direct current loads, and filtering and voltage stabilization are carried out through elements such as a capacitor and an inductor;
the AC/DC converter actively adjusts the electric quantity of power, voltage and current of a feeder line to be transferred, and realizes near-zero current disconnection and active synchronous closing of a feeder line switch;
the dynamic partition controller dynamically partitions the power distribution network based on the data monitored in real time, and adjusts the output power of the direct current bus and the partition scheme according to the requirement;
the direct current load obtains the required direct current from the direct current bus, and reduces the loss and cost of energy conversion.
It should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made thereto without departing from the spirit and scope of the technical solution of the present invention, which is intended to be covered by the scope of the claims of the present invention.
Claims (10)
1. A dynamic partitioning method for a power distribution network containing embedded direct current is characterized by comprising the following steps: comprising the steps of (a) a step of,
embedding a multi-terminal direct current distribution network which is in a disconnection state at ordinary times;
the voltage and the electric quantity of current of a feeder line are actively regulated through an AC/DC converter of AC/DC interconnection equipment, so that near-zero current disconnection and active synchronous closing of a feeder line switch are realized;
and the AC/DC converter is utilized for flexibly adjusting and actively synchronizing the power flow, so that dynamic partition power supply among different areas is realized.
2. A method for dynamic partitioning of a power distribution network comprising embedded dc as recited in claim 1, wherein: the multi-terminal direct current distribution network comprises an AC/DC converter of an AC/DC interconnection device in an embedded direct current link to actively regulate the electric quantity of power, voltage and current of a feeder line to be transferred, so as to realize near-zero current disconnection and active synchronous closing of a feeder line switch.
3. A method for dynamic partitioning of a power distribution network comprising embedded dc as recited in claim 2, wherein: the AC/DC converter comprises a 10kV feeder line of each alternating-current end, the 10kV feeder line of each alternating-current end is connected with the bidirectional AC/DC converter and is connected with the bidirectional AC/DC converter through a shared medium-voltage direct-current bus, and the AC/DC converter adopts a modularized converter, a two-level converter and a three-level converter.
4. A method for dynamic partitioning of a power distribution network comprising embedded dc as recited in claim 3, wherein: the method comprises the steps that the AC/DC converter actively adjusts the voltage and the electric quantity of the current of a feeder line, namely, the active power and the reactive power of a feeder line switch are continuously adjusted by changing the control mode of the AC/DC converter in an embedded direct current network, when the active power and the reactive power are zero, the current flowing through the feeder line switch is zero, the voltage difference between two ends of a contact switch is also zero, and a temporary overvoltage can be ignored when the switch is disconnected;
after the voltage synthesis, the controller of the converter is connected with the voltage amplitude output by the inner loop and the phase value output by the phase-locked loop into PWM for modulation.
5. The method for dynamically partitioning a power distribution network comprising embedded direct current as recited in claim 4, wherein: the near-zero current disconnection comprises the steps of changing the control mode of the AC/DC converter at the overload area side into VSG control VF control when the load unbalance and partial load overload phenomenon occur in the power supply area, actively regulating the power flowing through the feeder switch, and enabling the current flowing through the feeder switch to be zero when the active power and the reactive power are zero, so that the zero current disconnection is completed.
6. The method for dynamically partitioning a power distribution network comprising embedded direct current as recited in claim 5, wherein: the active synchronous closing comprises the steps of actively adjusting the voltage amplitude and the phase of a contact switch by utilizing VSG control of an AC/DC converter of an embedded direct current system, and closing the switch when the voltage deviation of two ends of the switch is minimum, so as to realize active synchronous closing.
7. The method for dynamically partitioning a power distribution network comprising embedded direct current as recited in claim 6, wherein: the dynamic partitioning comprises the steps of utilizing an AC/DC converter of an embedded direct current system to adjust the power, voltage and current of a switch, dividing a load from an overload area to a power supply area, and realizing dynamic area division and uninterrupted power actions of the dynamic division area of a power distribution network.
8. A system employing a method for dynamic partitioning of a power distribution network comprising embedded dc as claimed in any of claims 1 to 7, wherein: the system comprises an embedded direct current inverter, a direct current bus, an AC/DC converter, a dynamic partition controller and a direct current load;
the embedded direct current inverter converts alternating current into direct current and embeds the direct current into a power grid;
the direct current buses are used for receiving direct current from each embedded direct current inverter and transmitting the direct current to different direct current loads, and filtering and voltage stabilization are carried out through elements such as a capacitor and an inductor;
the AC/DC converter actively adjusts the electric quantity of power, voltage and current of a feeder line to be transferred, and realizes near-zero current disconnection and active synchronous closing of a feeder line switch;
the dynamic partition controller dynamically partitions the power distribution network based on the data monitored in real time, and adjusts the output power of the direct current bus and the partition scheme according to the requirement;
the direct current load obtains the required direct current from the direct current bus, and reduces the loss and cost of energy conversion.
9. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method of any of claims 1 to 7 when the computer program is executed.
10. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 7.
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