CN113363958B - DC power distribution network instability source positioning method - Google Patents
DC power distribution network instability source positioning method Download PDFInfo
- Publication number
- CN113363958B CN113363958B CN202110625078.2A CN202110625078A CN113363958B CN 113363958 B CN113363958 B CN 113363958B CN 202110625078 A CN202110625078 A CN 202110625078A CN 113363958 B CN113363958 B CN 113363958B
- Authority
- CN
- China
- Prior art keywords
- converter
- instability
- node
- source
- right half
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- 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
-
- 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
-
- 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]
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The invention discloses a power distribution network instability source positioning method based on system loop gain perception and bus port impedance information circulation self-construction. The method does not depend on expert experience, greatly saves manpower, is beneficial to improving the checking and correcting level of the running stability of the direct-current power distribution network, and has great engineering application value and popularization prospect.
Description
Technical Field
The invention relates to the technical field of fault detection of direct current power distribution networks, in particular to a method for positioning a instability source of a complex direct current power distribution network in real time based on impedance information of a converter.
Background
With the increasing use of new energy resources such as photovoltaic energy, wind energy and the like and the increasing of direct current loads such as automobiles, illumination and the like, the loads of a direct current power distribution network are more complex. Although each converter in the system is stable when individually designed and tested, when they actually constitute a dc distribution system, oscillation or even instability of the entire system is induced due to mismatch between different converters. The system instability category is complex, and comprises instability of the converter and instability caused by coupling between the converters. At present, the related technology is lacked for positioning the instability source of the system, and especially the positioning of the instability source of the different instability categories is considered.
The patent document with the publication number of 111798163A, namely 'an active power distribution network safety assessment method', firstly, the instability probability of an active power distribution network is calculated; then establishing a space-time model of the active power distribution network; and finally, based on the instability probability of the active power distribution network, establishing a diffraction index, a focusing index, a sputtering index and a global index through the space-time model, and evaluating the safety of the active power distribution network according to the four indexes. The solution is relatively complex.
The patent document 112217191a, "a method for analyzing stability of a dc power distribution network based on a node impedance matrix", merely determines whether a system is unstable, and cannot find out the specific location and type of the instability.
Therefore, the research on a simple and efficient instability positioning method has important significance for guaranteeing the safety of the power grid.
Disclosure of Invention
The invention provides a branch distribution network instability positioning method based on system loop gain perception and bus port impedance information circulation self-construction.
A direct current distribution network instability source positioning method is based on system loop gain perception and bus port impedance information circulation self-construction, and comprises the following steps:
obtaining the impedance value of each converter in the power distribution network, establishing an equivalent impedance model of the whole system, classifying various converters into a converter for controlling bus voltage and a converter for controlling bus current, placing the converter for controlling bus voltage on one side, placing the converter for controlling bus current on the other side, and calculating the loop gain of the system according to the impedance value;
judging whether the system is stable or not according to the closed-loop equivalent loop gain of the system and whether the number of poles of the right half-plane is 0 or not;
under the condition of system instability, judging whether the instability type of the system belongs to three types of instability states caused by converter interaction, instability states caused by instability in the converter, and instability states caused by converter interaction and instability in the converter at the same time according to whether the number of poles of a right half plane of the gain equivalent loop of the open loop of the system and the number of times of points (-1, j0) encircled by a curve of the right half plane are 0 or not;
after the system instability type is determined, a central node is used as an initial node for calculation, admittance under the condition that the left side or the right side of the node contains and does not contain the node is calculated respectively, the distribution of the zero-pole points of the right half plane of the left side or the right side of the node containing the admittance under the condition of the node and the distribution of the zero-pole points of the right half plane of the left side or the right side of the node not containing the admittance under the condition of the node are calculated, the position relation between the instability source and the node is judged, and then iteration is repeated until the instability source is found.
The method for judging the type of the system instability comprises the following steps:
and if the number of poles of the right half plane of the system open-loop equivalent loop gain is 0, determining that the interaction between the converters is unstable, if not, continuously calculating the number of times that the system open-loop equivalent loop gain surrounds (-1, j0), if the number of times is 0, determining that the converter is unstable in the converter, and if the number of times is not 0, determining that the converter is unstable in the converter, and determining that the converter is unstable in a unstable state caused by the interaction and the instability in the converter.
And judging the position relationship between the instability source and the node, wherein the instability source is positioned at the node, the instability source is positioned at the left side of the node, and the instability source is positioned at the right side of the node.
The specific search method of the instability source specifically comprises the following steps:
selecting a system center point as an initial point;
calculating the equivalent total admittance right half-plane pole number of a port at one side of a converter for controlling the bus current of the current node, if the equivalent total admittance right half-plane pole number is 0, judging that a destabilization source only exists in the node converter, if the equivalent total admittance right half-plane pole number is not 0, calculating the equivalent total admittance right half-plane pole number of the converter for controlling the bus current of the system, if the equivalent total admittance right half-plane pole number is greater than the equivalent total admittance right half-plane pole number at the other side of the node, judging that the destabilization source not only exists in the current node, but also exists in the node at one side of the converter for controlling the bus current, otherwise, the destabilization source only exists in the node at one side of the converter for controlling the bus current;
repeating iteration until all instability sources in the converter for controlling the bus current are found;
the same look-up is made for the converter controlling the bus voltage.
Has the advantages that: the invention provides a power distribution network instability positioning method based on system loop gain perception and bus port impedance information circulation self-construction, and the power distribution network instability problem can be conveniently and effectively solved.
Drawings
FIG. 1 is a flow chart of the present invention.
Fig. 2 is a schematic diagram of the equivalent impedance transformation of the system of the present invention.
Fig. 3 is a schematic diagram of a system instability fault type determination process according to the present invention.
Fig. 4 is a schematic diagram of a system instability source positioning process according to the present invention.
Detailed Description
The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.
Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.
The invention is further illustrated by the following examples:
the method of the invention, as shown in fig. 1, comprises:
s1, establishing an equivalent impedance model of a power distribution network
S2, judging whether the system is unstable or not and judging the type of the unstable
S3, searching for the position of the instability source of the system
Step s1, establishing an equivalent impedance model of the power distribution network, as shown in fig. 2, including:
and S11, dividing the converter into a converter for controlling the bus current and a converter for controlling the bus voltage according to the dominant characteristics of the converter.
S12, converting the original converter into a corresponding standard model according to different converter types according to Thevenin and Nonton theorem
And S13, in the converted equivalent impedance model, placing a converter for controlling the bus current on the left side and placing a converter for controlling the bus voltage on the right side.
Step s2, determining whether the system is unstable and the instability type, as shown in fig. 3, where the instability type includes:
i a destabilization state caused by converter interaction;
II, a destabilization state caused by instability in the converter;
III unstable state caused by mutual converter interaction and internal instability of converter
The distinguishing process comprises the following steps:
s21, calculating equivalent gain T of system loopm,P(1+Tm) And P (T)m) The number of poles on the right half-plane representing the equivalent gain of the closed loop of the system and the equivalent gain of the loop of the system, TmThe expression is as follows:
s22, judging P (1+ T)m) Whether or not it is equal to 0. If P (1+ T)m) Judging that the system is stable if the value is 0; if P (1+ T)m) If not equal to 0, the system is unstable, and the process proceeds to S23.
S23, judging P (T)m) Whether or not it is equal to 0. If P (T)m) And (5) judging that the system instability is of instability type I: instability caused by interaction between transducers; if P (T)m) Not equal to 0, further judgment is needed.
S24, judging TmWhether the number of times of wrap (-1, j0) is 0. If the surrounding times are 0, judging that the system instability is instability type II: by convertersA destabilization state caused by instability of the interior of the body; if the surrounding times are not 0, judging that the system instability is instability type III: a destabilizing condition caused by both converter interaction and converter internal instability.
Step s3, finding a source position of the system instability source, as shown in fig. 4, includes:
s31, taking the central node as an initial node, and calculating the port equivalent total admittance Y of all control bus current converters on the left sideleftSame as P (Y)left) The number of right half-plane poles of the port equivalent total admittance of all the control bus current transformers on the left side is shown.
S32, calculating the port equivalent total admittance Y of all control bus current converters on the left side of the current nodeleftiSame as P (Y)lefti) And the number of right half-plane poles of the port equivalent total admittance of all the control bus current transformers on the left side of the current node is shown.
S33, judging P (Y)lefti) Whether or not it is equal to 0. If P (Y)lefti) And if the current node is equal to 0, the instability source on the left side of the system only exists in the converter which controls the bus current at the current node. P (Y)left1) Not equal to 0, further judgment is needed.
S34, comparing P (Y)left) And P (Y)lefti) Size. If P (Y)left1)<P(Yleft) It means that the source of instability on the left side of the system exists not only in the current node but also in the controller on the left side of the node. On the contrary, if P (Y)left1)<P(Yleft) Then the source of instability exists in the controller to the left of the current node.
And S35, if the left side still has the instability source, moving the current node to the left.
And S36, repeating S32-S35 until all the instability converters in the converter for controlling the bus current on the left side are found.
S37, repeating S31-36 for the converter for controlling the bus voltage on the right side. I.e. admittance Y is replaced by impedance Z and left side is replaced by right side. All the unstable converters in the converter controlling the bus voltage on the right side are found.
The method is beneficial to improving the checking and correcting level of the running stability of the direct-current power distribution network, and has a great engineering application value and a great popularization prospect.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein. The scheme in the embodiment of the application can be implemented by adopting various computer languages, such as object-oriented programming language Java and transliterated scripting language JavaScript.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks. These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all alterations and modifications as fall within the scope of the application. It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.
Claims (4)
1. A method for positioning a DC power distribution network instability source is characterized by comprising the following steps: based on system loop gain perception and bus port impedance information cycle self-construction, the method comprises the following steps:
obtaining the impedance value of each converter in the power distribution network, establishing an equivalent impedance model of the whole system, classifying various converters into a converter for controlling bus voltage and a converter for controlling bus current, placing the converter for controlling bus voltage on one side, placing the converter for controlling bus current on the other side, and calculating the loop gain of the system according to the impedance value;
judging whether the system is stable or not according to the closed-loop equivalent loop gain of the system and whether the number of poles of the right half-plane is 0 or not;
under the condition of system instability, judging whether the instability type of the system belongs to three types of instability states caused by converter interaction, instability states caused by instability in the converter, and instability states caused by converter interaction and instability in the converter at the same time according to whether the number of poles of a right half plane of the gain equivalent loop of the open loop of the system and the number of times of points (-1, j0) encircled by a curve of the right half plane are 0 or not;
after the system instability type is determined, a central node is used as an initial node for calculation, admittance under the condition that the left side or the right side of the node contains and does not contain the node is calculated respectively, the distribution of the zero-pole points of the right half plane of the left side or the right side of the node containing the admittance under the condition of the node and the distribution of the zero-pole points of the right half plane of the left side or the right side of the node not containing the admittance under the condition of the node are calculated, the position relation between the instability source and the node is judged, and then iteration is repeated until the instability source is found.
2. The method for positioning the instability source of the direct-current distribution network according to claim 1, characterized in that: the method for judging the type of the system instability comprises the following steps:
and if the number of poles of the right half plane of the system open-loop equivalent loop gain is 0, determining that the interaction between the converters is unstable, if not, continuously calculating the number of times that the system open-loop equivalent loop gain surrounds (-1, j0), if the number of times is 0, determining that the converter is unstable in the converter, and if the number of times is not 0, determining that the converter is unstable in the converter, and determining that the converter is unstable in a unstable state caused by the interaction and the instability in the converter.
3. The method for positioning the instability source of the direct-current distribution network according to claim 1, characterized in that: and judging the position relationship between the instability source and the node, wherein the instability source is positioned at the node, the instability source is positioned at the left side of the node, and the instability source is positioned at the right side of the node.
4. The method for positioning the instability source of the direct-current distribution network according to claim 1, characterized in that: the method for searching the instability source specifically comprises the following steps:
selecting a system center point as an initial point;
calculating the equivalent total admittance right half-plane pole number of a port at one side of a converter for controlling the bus current of the current node, if the equivalent total admittance right half-plane pole number is 0, judging that a destabilization source only exists in the node converter, if the equivalent total admittance right half-plane pole number is not 0, calculating the equivalent total admittance right half-plane pole number of the converter for controlling the bus current of the system, if the equivalent total admittance right half-plane pole number is greater than the equivalent total admittance right half-plane pole number at the other side of the node, judging that the destabilization source not only exists in the current node, but also exists in the node at one side of the converter for controlling the bus current, otherwise, the destabilization source only exists in the node at one side of the converter for controlling the bus current;
repeating iteration until all instability sources in the converter for controlling the bus current are found;
the same look-up is done for the converter controlling the bus voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110625078.2A CN113363958B (en) | 2021-06-04 | 2021-06-04 | DC power distribution network instability source positioning method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110625078.2A CN113363958B (en) | 2021-06-04 | 2021-06-04 | DC power distribution network instability source positioning method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113363958A CN113363958A (en) | 2021-09-07 |
| CN113363958B true CN113363958B (en) | 2022-05-20 |
Family
ID=77532284
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110625078.2A Active CN113363958B (en) | 2021-06-04 | 2021-06-04 | DC power distribution network instability source positioning method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113363958B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105119265A (en) * | 2015-09-06 | 2015-12-02 | 南方电网科学研究院有限责任公司 | Radial direct-current power grid stability judgment method and system |
| CN109742748A (en) * | 2019-02-28 | 2019-05-10 | 东南大学 | A kind of stability criterion method suitable for multi-voltage grade direct-flow distribution system |
| CN109830980A (en) * | 2019-01-31 | 2019-05-31 | 张欣 | It is a kind of for judging the criterion method of the system stability of multi-level inverter parallel connection spreading cable |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140292298A1 (en) * | 2013-04-01 | 2014-10-02 | Lsi Corporation | Operational Amplifier-Based Current-Sensing Circuit for DC-DC Voltage Converters and The Like |
-
2021
- 2021-06-04 CN CN202110625078.2A patent/CN113363958B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105119265A (en) * | 2015-09-06 | 2015-12-02 | 南方电网科学研究院有限责任公司 | Radial direct-current power grid stability judgment method and system |
| CN109830980A (en) * | 2019-01-31 | 2019-05-31 | 张欣 | It is a kind of for judging the criterion method of the system stability of multi-level inverter parallel connection spreading cable |
| CN109742748A (en) * | 2019-02-28 | 2019-05-10 | 东南大学 | A kind of stability criterion method suitable for multi-voltage grade direct-flow distribution system |
Non-Patent Citations (6)
| Title |
|---|
| DC impedance modeling, stability analysis and active stabilization of the VSC-HVDC system;Wenhua Wu;《IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society》;20171218;全文 * |
| Impedance-Based Stability Analysis Methods for DC Distribution Power System With Multivoltage Levels;Han Mu;《IEEE Transactions on Power Electronics》;20210209;第36卷(第8期);全文 * |
| 分布式电源级联系统稳定性分析与增强控制;王伟等;《电力电子技术》;20191120(第11期);全文 * |
| 直流分布式电源系统稳定性判据研究综述;王久和等;《发电技术》;20200430(第02期);全文 * |
| 直流微电网稳定性分析及阻尼控制方法研究;郭力等;《中国电机工程学报》;20160220(第04期);全文 * |
| 级联变换器系统的小信号模型及稳定性判据;夏绪伟等;《电力建设》;20150630(第06期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113363958A (en) | 2021-09-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Alinejad-Beromi et al. | Using genetic alghoritm for distributed generation allocation to reduce losses and improve voltage profile | |
| Sedighizadeh et al. | Using genetic algorithm for distributed generation allocation to reduce losses and improve voltage profile | |
| CN108020750A (en) | A kind of power distribution network power failure range analysis method and analytical equipment | |
| CN112163304A (en) | Transmission network redundancy constraint identification method, storage medium and computing device | |
| CN111582630A (en) | Method and system for determining low-voltage transformer area line loss rate evaluation value | |
| CN113363958B (en) | DC power distribution network instability source positioning method | |
| CN114386323A (en) | Power distribution network reactive power optimization method containing distributed power supply based on improved butterfly algorithm | |
| CN112560222A (en) | Reactive power optimization configuration method for improving dynamic stability of power grid | |
| CN115954956A (en) | Method and system for evaluating access capacity of distributed power supply of power distribution network | |
| CN115618753A (en) | Hybrid energy storage system joint optimization method for frequency-adjustable pulse working condition | |
| CN111697607A (en) | Multi-terminal flexible direct-current transmission receiving-end power grid access method and system | |
| CN114389265A (en) | Power grid emergency load optimization method and system based on proliferation and reduced evolution | |
| Zhou et al. | Voltage regulation based on deep reinforcement learning algorithm in distribution network with energy storage system | |
| Weike et al. | Fuzzy neural networks and GA based predictive control for active power filter | |
| CN112699922A (en) | Self-adaptive clustering method and system based on intra-region distance | |
| CN111301214A (en) | Electric automobile ordered charging control method and system | |
| Yinghua et al. | The multi-join query optimization for smart grid data | |
| CN112994025B (en) | Power grid load removal method and system based on linear programming algorithm | |
| CN116722549B (en) | Hierarchical control method and device for power distribution network based on high-precision simulation technology | |
| CN113363959A (en) | Virtual impedance construction method for three-phase inverter | |
| CN109816247B (en) | Power grid investment decision modeling method and device for associating transformation measures with line heavy load | |
| CN114139957B (en) | Evaluation method for rural area transformer area voltage and line loss influence based on XGBoost algorithm | |
| CN113555909B (en) | Multi-energy complementary base wind-light-fire storage construction time sequence optimization method and system | |
| CN112928773B (en) | Method and system for quantifying maximum access scale of new energy | |
| CN115828475A (en) | Cable line direct fluidization transformation current-carrying capacity calculation method and system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |