CN109873415B - Equivalent method and device for power system - Google Patents
Equivalent method and device for power system Download PDFInfo
- Publication number
- CN109873415B CN109873415B CN201711247673.7A CN201711247673A CN109873415B CN 109873415 B CN109873415 B CN 109873415B CN 201711247673 A CN201711247673 A CN 201711247673A CN 109873415 B CN109873415 B CN 109873415B
- Authority
- CN
- China
- Prior art keywords
- bus node
- impedance
- fault
- equivalent
- equivalence
- 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
- 238000000034 method Methods 0.000 title claims abstract description 56
- 230000003068 static effect Effects 0.000 claims abstract description 50
- 238000012545 processing Methods 0.000 claims description 22
- 238000011084 recovery Methods 0.000 abstract description 27
- 238000011160 research Methods 0.000 abstract description 8
- 238000004088 simulation Methods 0.000 description 14
- 238000004590 computer program Methods 0.000 description 3
- 230000006870 function Effects 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000004422 calculation algorithm Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Images
Landscapes
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The embodiment of the invention provides a power system equivalence method and device, relates to the technical field of power system equivalence, and can conveniently research the voltage recovery characteristic of a bus node of a power system after a fault occurs. The method comprises the following steps: determining a first bus node which needs to be reserved by the power system; multi-port Thevenin equivalence is carried out on the first bus node to obtain equivalent self-impedance of the first bus node; performing static equivalence on the first bus node; calculating the variable impedance before the first bus node fails and the variable impedance after the first bus node fails according to the equivalent self-impedance of the first bus node; and converting the equivalent power model after the static equivalence of the first bus node into a pre-fault equivalent power model consisting of an ideal voltage source and the variable impedance before the fault of the first bus node and a post-fault equivalent power model consisting of the ideal voltage source and the variable impedance after the fault of the first bus node according to the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node.
Description
Technical Field
The invention relates to the field of power system equivalence, in particular to a power system equivalence method and device.
Background
Power system equivalence is a modeling method that simplifies power systems to reduce scale. The scale of the power system is reduced by dividing the power system into an internal system (a system to be researched) and an external system (a system far away from the internal system), reserving the internal system and boundary nodes between the internal system and the external system, and equating the external system. The power system equivalence is divided into static equivalence and dynamic equivalence. The static equivalence does not consider the dynamic characteristics of elements, and the generator set of the external system is equalized into a plurality of ideal voltage sources. The dynamic equivalence considers the dynamic characteristics of elements, equates the generator set of an external system into a plurality of new generator sets, and is suitable for researching the characteristics of steady state, transient state power angle stability, voltage stability, dynamic stability and the like of a power system. The static equivalence method is simple but only suitable for overvoltage calculation, and the dynamic equivalence method is wide in application range but complex in process and consumes more labor and time.
Sometimes, it is only necessary to study the voltage recovery characteristics of a part of bus nodes in the power system after a fault, for example, the voltage recovery characteristics of the bus nodes after a fault in HVDC (high-voltage direct current) or statcom (static Synchronous converter). In the research of the problems, static equivalence cannot research dynamic characteristics, and dynamic equivalence consumes unnecessary manpower and material resources because of too much detail. Therefore, at present, a simplified equivalence method suitable for the research of the problems does not exist, and only a dynamic equivalence method can be carried out, so that more labor and time are consumed in the research.
Disclosure of Invention
The embodiment of the invention provides an equivalent method and device for an electric power system, which can research the voltage recovery characteristic of a bus node of the electric power system after a fault occurs more quickly and conveniently.
In order to achieve the above purpose, the embodiment of the invention adopts the following technical scheme:
in a first aspect, there is provided a power system equivalent method, comprising:
determining a first bus node which needs to be reserved by the power system; multi-port Thevenin equivalence is carried out on the first bus node to obtain equivalent self-impedance of the first bus node; carrying out static equivalence on a first bus node to obtain an equivalent power source model of the first bus node; calculating the variable impedance before the first bus node fails and the variable impedance after the first bus node fails according to the equivalent self-impedance of the first bus node; and converting the equivalent power model after the static equivalence of the first bus node into a pre-fault equivalent power model consisting of an ideal voltage source and the variable impedance before the fault of the first bus node and a post-fault equivalent power model consisting of the ideal voltage source and the variable impedance after the fault of the first bus node according to the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node.
Optionally, the equivalent self-impedance includes a first equivalent self-impedance and a second equivalent self-impedance; the multi-port Thevenin equivalence of the first busbar node to obtain the equivalent self-impedance of the first busbar node comprises the following steps:
when a generator set in the power system adopts an E 'constant model, multi-port Thevenin equivalence is carried out on a first bus node to obtain a first equivalent self-impedance Z' of the first bus node;
when a generator set in the power system adopts an E 'constant model, multi-port Thevenin equivalence is carried out on a first bus node to obtain a second equivalent self-impedance Z' of the first bus node.
Further optionally, calculating the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node according to the equivalent self-impedance of the first bus node includes:
taking the first equivalent self-impedance Z' of the first bus node as the variable impedance Z before the first bus node failsFront side；
The variable impedance after the fault of the first bus node is calculated according to the following formula:
Zrear end＝Z”+(Z'-Z”)*e-αt；
Wherein Z isRear endAnd alpha is a decay time constant, and t is fault time.
In a second aspect, there is provided a power system equivalent device, comprising: the device comprises a judging module, a processing module and an equivalence module;
the judging module is used for determining a first bus node which needs to be reserved by the power system;
the processing module is used for carrying out multi-port Thevenin equivalence on the first bus node determined by the judging module so as to obtain equivalent self-impedance of the first bus node;
the equivalence module is used for carrying out static equivalence on the first bus node determined by the judgment module so as to obtain a first equivalence power supply model of the first bus node;
the processing module is also used for calculating the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node according to the equivalent self-impedance of the first bus node;
the processing module is further used for converting the equivalent power source model after the static equivalence of the first bus node into a pre-fault equivalent power source model consisting of an ideal voltage source and the variable impedance before the fault of the first bus node and a post-fault equivalent power source model consisting of the ideal voltage source and the variable impedance after the fault of the first bus node according to the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node.
Optionally, the equivalent self-impedance includes a first equivalent self-impedance and a second equivalent self-impedance; the processing module is specifically configured to:
when a generator set in the power system adopts an E 'constant model, multi-port Thevenin equivalence is carried out on a first bus node to obtain a first equivalent self-impedance Z' of the first bus node; when a generator set in the power system adopts an E 'constant model, multi-port Thevenin equivalence is carried out on a first bus node to obtain a second equivalent self-impedance Z' of the first bus node.
Optionally, the processing module is specifically configured to:
taking the first equivalent self-impedance Z' of the first bus node as the variable impedance Z before the first bus node failsFront side；
The variable impedance after the fault of the first bus node is calculated according to the following formula:
Zrear end＝Z”+(Z'-Z”)*e-αt；
The variable impedance after the first bus node is in fault is shown, alpha is a decay time constant, and t is fault time.
In a third aspect, there is provided a computer readable storage medium containing one or more programs which, when executed by a computer, cause the computer to perform a power system equivalent method as provided in the first aspect.
The embodiment of the invention provides an equivalent method and a device of a power system, wherein the method comprises the following steps: determining a first bus node which needs to be reserved by the power system; multi-port Thevenin equivalence is carried out on the first bus node to obtain equivalent self-impedance of the first bus node; performing static equivalence on the first bus node; calculating the variable impedance before the first bus node fails and the variable impedance after the first bus node fails according to the equivalent self-impedance of the first bus node; and converting the equivalent power model after the static equivalence of the first bus node into a pre-fault equivalent power model consisting of an ideal voltage source and the variable impedance before the fault of the first bus node and a post-fault equivalent power model consisting of the ideal voltage source and the variable impedance after the fault of the first bus node according to the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node. According to the scheme provided by the embodiment of the invention, before static equivalence of the power system, the equivalent self-impedance of a first bus node needing to be reserved is obtained by using a multi-port Thevenin equivalence method, after the static equivalence of the power system, the variable impedance values of the first bus node before and after a fault are obtained by calculating according to the equivalent self-impedance of the first bus node, and then an equivalent power model obtained after the static equivalence of the first bus node is converted into an equivalent power model consisting of a rational voltage source and variable impedance; and then, simulating the voltage recovery characteristic of the power system after the bus node fault according to the converted equivalent power source model and the model after the static equivalence of other parts of the power system. Compared with the prior art that the power system uses a dynamic equivalence method to obtain an equivalent power system model for carrying out analog simulation of voltage recovery characteristics after bus node failure, the scheme provided by the embodiment of the invention is that a certain change is made to the equivalent power model on the basis of a static equivalence method, so that the analog simulation of the voltage recovery characteristics after bus node failure is sufficiently completed, and the method is faster and more convenient than the prior art.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic flow chart of an equivalent method of an electric power system according to an embodiment of the present invention;
FIG. 2 is a schematic flow chart of an equivalent method of an electrical power system according to another embodiment of the present invention;
fig. 3 is a schematic structural diagram of a bus node that needs to be reserved in an electrical power system according to an embodiment of the present invention;
fig. 4 is a schematic diagram comparing a voltage recovery characteristic curve generated by simulation of a power system model obtained after equivalence of a power system by using the power system equivalence method according to the embodiment of the present invention with an actual voltage recovery characteristic curve of the power system;
fig. 5 is an equivalent device of an electric power system according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that, in the embodiments of the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "e.g.," an embodiment of the present invention is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.
It should be noted that, in the embodiments of the present invention, "of", "corresponding" and "corresponding" may be sometimes used in combination, and it should be noted that, when the difference is not emphasized, the intended meaning is consistent.
For the convenience of clearly describing the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, the words "first", "second", and the like are used for distinguishing the same items or similar items with basically the same functions and actions, and those skilled in the art can understand that the words "first", "second", and the like are not limited in number or execution order.
When a simulation experiment needs to be carried out on the bus voltage recovery characteristic of the power system, firstly, equivalence needs to be carried out on the power system to establish a small-scale model, and the equivalence method of the power system comprises static equivalence and dynamic equivalence, wherein the static equivalence cannot research the dynamic characteristic of the power system so that the power system cannot be used, and the dynamic equivalence can research various dynamic characteristics of the power system and also comprises the bus voltage recovery characteristic; however, the dynamic equivalence process is complex, and only in terms of researching the bus voltage characteristic, the dynamic equivalence process is too complex and consumes unnecessary manpower and material resources.
In view of the above problem, referring to fig. 1, an embodiment of the present invention provides an equivalent method for an electric power system, including:
101. a first bus node that the power system needs to reserve is determined.
102. And carrying out multi-port Thevenin equivalence on the first bus node to obtain the equivalent self-impedance of the first bus node.
Specifically, a circuit in the first bus node is changed into a circuit consisting of an ideal voltage source and equivalent self-impedance according to thevenin's theorem, so that the equivalent self-impedance of the first bus node is obtained.
103. And carrying out static equivalence on the first bus node to obtain an equivalent power source model of the first bus node.
Specifically, since the voltage recovery characteristics after the bus node failure in the power system are mainly related to the power supply, an equivalent power supply model of the first bus node needs to be obtained here.
104. And calculating the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node according to the equivalent self-impedance of the first bus node.
Since the voltage recovery characteristics after a bus fault of the power system need to be studied, it is necessary to obtain the characteristics before and after the fault when obtaining the variable impedance.
105. And converting the equivalent power model after the static equivalence of the first bus node into a pre-fault equivalent power model consisting of an ideal voltage source and the variable impedance before the fault of the first bus node and a post-fault equivalent power model consisting of the ideal voltage source and the variable impedance after the fault of the first bus node according to the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node.
Specifically, the power supply of the first bus bar node before and after the equivalence and before and after the fault is not changed, so the rational voltage source is obtained when the equivalent self-impedance of the first bus bar node is obtained.
According to the equivalent method of the power system provided by the embodiment on the market, before static equivalence of the power system, the equivalent self-impedance of a first bus node needing to be reserved is obtained by using a multi-port Thevenin equivalent method, after the static equivalence of the power system, the variable impedance values of the first bus node before and after a fault are calculated according to the equivalent self-impedance of the first bus node, and then an equivalent power model obtained after the static equivalence of the first bus node is converted into an equivalent power model consisting of a rational voltage source and variable impedance; and then, simulating the voltage recovery characteristic of the power system after the bus node fault according to the converted equivalent power source model and the model after the static equivalence of other parts of the power system. Compared with the prior art that the power system uses a dynamic equivalence method to obtain an equivalent power system model for carrying out analog simulation of voltage recovery characteristics after bus node failure, the scheme provided by the embodiment of the invention is that a certain change is made to the equivalent power model on the basis of a static equivalence method, so that the analog simulation of the voltage recovery characteristics after bus node failure is sufficiently completed, and the method is faster and more convenient than the prior art.
Illustratively, referring to fig. 2, another power system equivalent method is further provided as a more specific supplementary description of the power system equivalent method provided by the foregoing embodiment, where the method includes:
201. a first bus node that the power system needs to reserve is determined.
2021. When a generator set in the power system adopts an E 'constant model, multi-port Thevenin equivalence is carried out on a first bus node to obtain a first equivalence self-impedance Z' of the first bus node.
2022. When a generator set in the power system adopts an E 'constant model, multi-port Thevenin equivalence is carried out on a first bus node to obtain a second equivalent self-impedance Z' of the first bus node.
Specifically, in the actual simulation, a power supply in the power system, that is, a generator set, has multiple models, and here, in order to ensure the accuracy of the final simulation, the self impedance of the generator set needs to be obtained on the basis that the generator set adopts different models, in the embodiment of the present invention, the generator set adopts two different models as an example for explanation.
203. And carrying out static equivalence on the first bus node to obtain an equivalent power source model of the first bus node.
204. Taking the first equivalent self-impedance Z' of the first bus node as the variable impedance Z before the first bus node failsFront side(ii) a Calculating the variable impedance Z after the first bus node fails according to a preset formulaRear end。
Wherein, the preset formula is as follows:
Zrear end＝Z”+(Z'-Z”)*e-αt；
Wherein Z isRear endThe variable impedance after the first bus node is in fault, alpha is an attenuation time constant, and t is fault time; illustratively, α ranges from 0.05 ± 0.02 seconds.
205. And converting the equivalent power model after the static equivalence of the first bus node into a pre-fault equivalent power model consisting of an ideal voltage source and the variable impedance before the fault of the first bus node and a post-fault equivalent power model consisting of the ideal voltage source and the variable impedance after the fault of the first bus node according to the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node.
The embodiment of the invention provides an equivalent method of a power system, which comprises the following steps: determining a first bus node which needs to be reserved by the power system; multi-port Thevenin equivalence is carried out on the first bus node to obtain equivalent self-impedance of the first bus node; performing static equivalence on the first bus node; calculating the variable impedance before the first bus node fails and the variable impedance after the first bus node fails according to the equivalent self-impedance of the first bus node; and converting the equivalent power model after the static equivalence of the first bus node into a pre-fault equivalent power model consisting of an ideal voltage source and the variable impedance before the fault of the first bus node and a post-fault equivalent power model consisting of the ideal voltage source and the variable impedance after the fault of the first bus node according to the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node. According to the scheme provided by the embodiment of the invention, before static equivalence of the power system, the equivalent self-impedance of a first bus node needing to be reserved is obtained by using a multi-port Thevenin equivalence method, after the static equivalence of the power system, the variable impedance values of the first bus node before and after a fault are obtained by calculating according to the equivalent self-impedance of the first bus node, and then an equivalent power model obtained after the static equivalence of the first bus node is converted into an equivalent power model consisting of a rational voltage source and variable impedance; and then, simulating the voltage recovery characteristic of the power system after the bus node fault according to the converted equivalent power source model and the model after the static equivalence of other parts of the power system. Compared with the prior art that the power system uses a dynamic equivalence method to obtain an equivalent power system model for carrying out analog simulation of voltage recovery characteristics after bus node failure, the scheme provided by the embodiment of the invention is that a certain change is made to the equivalent power model on the basis of a static equivalence method, so that the analog simulation of the voltage recovery characteristics after bus node failure is sufficiently completed, and the method is faster and more convenient than the prior art.
For example, the power system equivalence method provided in the above embodiment is described by taking an example of studying voltage recovery characteristics of a dc converter station bus node in a certain power system after a fault, and bus nodes (all 500kv bus nodes) to be reserved in the power system are shown in fig. 3, where the bus nodes to be reserved are a LY power plant bus node, an AH power plant bus node, a TA substation bus node, and a dc converter station bus node;
before the equivalence of the power system, multi-port Thevenin equivalence is carried out on each bus node under the condition that a generator set of each power plant adopts two models of E constant and E' constant, and the obtained equivalent self-impedance corresponding to each bus node is shown in the table 1.
TABLE 1
The reference value of the impedance per unit value is as follows: a capacity reference value of 100MVA and a voltage reference value of 525 kV;
and secondly, performing static equivalence on the power system, calculating the variable impedance values of each bus node before and after the fault according to the data in the table 1, and converting the equivalent power model after the static equivalence of each bus node into a pre-fault equivalent power model consisting of an ideal voltage source and the variable impedance before the fault of the bus node and a post-fault equivalent power model consisting of the ideal voltage source and the variable impedance after the fault of the bus node.
And thirdly, performing analog simulation on the voltage recovery characteristic of the bus node of the direct current converter station after one of the two circuits of the TA substation-direct current converter station has three-phase short circuit fault and is tripped according to the finally obtained equivalent model of the power system.
The voltage recovery characteristic curve of the bus node of the direct current converter station after the trip and the three-phase short-circuit fault of one of the two circuits of the TA substation-direct current converter station of the actual power system is shown by a solid line in FIG. 4, while the voltage recovery characteristic curve of the bus node of the direct current converter station, which is generated by the power system model simulation after equivalence by using the equivalence method provided by the embodiment of the invention, is shown by a dotted line in FIG. 4; the method and the device have good goodness of fit, and prove that the power system model generated by the power system equivalence method provided by the embodiment of the invention is completely competent for researching the bus node recovery characteristics, and is simpler and quicker than dynamic equivalence.
Referring to fig. 5, an embodiment of the present invention further provides an equivalent device 01 for an electric power system, including: a judging module 51, a processing module 52 and an equivalence module 53;
the judging module 51 is configured to determine a first bus node that needs to be reserved by the power system;
the processing module 52 is configured to perform multi-port thevenin equivalence on the first bus node determined by the determining module 51 to obtain an equivalent self-impedance of the first bus node;
the equivalence module 53 is configured to perform static equivalence on the first bus node determined by the determination module 51 to obtain a first equivalence power model of the first bus node;
the processing module 52 is further configured to calculate a variable impedance before the fault of the first bus node and a variable impedance after the fault of the first bus node according to the equivalent self-impedance of the first bus node;
the processing module 52 is further configured to convert the equivalent power model after the static equivalence of the first bus node into a pre-fault equivalent power model composed of the ideal voltage source and the variable impedance before the fault of the first bus node and a post-fault equivalent power model composed of the ideal voltage source and the variable impedance after the fault of the first bus node according to the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node.
Optionally, the equivalent self-impedance includes a first equivalent self-impedance and a second equivalent self-impedance; the processing module 52 is specifically configured to:
when a generator set in the power system adopts an E 'constant model, multi-port Thevenin equivalence is carried out on a first bus node to obtain a first equivalent self-impedance Z' of the first bus node; when a generator set in the power system adopts an E 'constant model, multi-port Thevenin equivalence is carried out on a first bus node to obtain a second equivalent self-impedance Z' of the first bus node.
Optionally, the processing module 52 is specifically configured to:
will be firstThe first equivalent self-impedance Z' of the bus node is used as the variable impedance Z before the first bus node failsFront side；
The variable impedance after the fault of the first bus node is calculated according to the following formula:
Zrear end＝Z”+(Z'-Z”)*e-αt；
The variable impedance after the first bus node is in fault is shown, alpha is a decay time constant, and t is fault time.
The power system equivalent device provided by the embodiment of the invention comprises: the device comprises a judging module, a processing module and an equivalence module; the judging module is used for determining a first bus node which needs to be reserved by the power system; the processing module is used for carrying out multi-port Thevenin equivalence on the first bus node determined by the judging module so as to obtain equivalent self-impedance of the first bus node; the equivalence module is used for carrying out static equivalence on the first bus node determined by the judgment module so as to obtain a first equivalence power supply model of the first bus node; the processing module is also used for calculating the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node according to the equivalent self-impedance of the first bus node; the processing module is further used for converting the equivalent power source model after the static equivalence of the first bus node into a pre-fault equivalent power source model consisting of an ideal voltage source and the variable impedance before the fault of the first bus node and a post-fault equivalent power source model consisting of the ideal voltage source and the variable impedance after the fault of the first bus node according to the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node. According to the scheme provided by the embodiment of the invention, before the static equivalence of the power system, the equivalent self-impedance of the first bus node needing to be reserved is obtained by using a multi-port Thevenin equivalence method, after the static equivalence of the power system, the variable impedance values of the first bus node before and after the fault are calculated according to the equivalent self-impedance of the first bus node, and then the equivalent power model obtained after the static equivalence of the first bus node is converted into the equivalent power model consisting of the rational voltage source and the variable impedance; and then, simulating the voltage recovery characteristic of the power system after the bus node fault according to the converted equivalent power source model and the model after the static equivalence of other parts of the power system. Compared with the prior art that the power system uses a dynamic equivalence method to obtain an equivalent power system model for carrying out analog simulation of voltage recovery characteristics after bus node failure, the scheme provided by the embodiment of the invention is that a certain change is made to the equivalent power model on the basis of a static equivalence method, so that the analog simulation of the voltage recovery characteristics after bus node failure is sufficiently completed, and the method is faster and more convenient than the prior art.
Embodiments of the present invention also provide a computer-readable storage medium containing one or more programs, which when executed by a computer, cause the computer to perform an equivalent method of a power system provided by an embodiment of the present invention.
The steps of a method or algorithm described in connection with the disclosure herein may be embodied in hardware or in software instructions executed by a processor. Embodiments of the present invention also provide a storage medium that may include a memory for storing computer software instructions for a power system equivalence method that includes program code designed to perform the power system equivalence method. Specifically, the software instructions may be composed of corresponding software modules, and the software modules may be stored in a Random Access Memory (RAM), a flash Memory, a Read Only Memory (ROM), an Erasable Programmable Read Only Memory (EPROM), an Electrically Erasable Programmable Read Only Memory (EEPROM), a register, a hard disk, a removable hard disk, a compact disc Read Only Memory (CD-ROM), or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. Of course, the storage medium may also be integral to the processor. The processor and the storage medium may reside in an ASIC. Additionally, the ASIC may reside in a core network interface device. Of course, the processor and the storage medium may reside as discrete components in a core network interface device.
The embodiment of the invention also provides a computer program which can be directly loaded into the memory and contains software codes, and the computer program can realize the equivalent method of the power system after being loaded and executed by the computer.
Those skilled in the art will recognize that, in one or more of the examples described above, the functions described in this invention may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer.
The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (5)
1. An electrical power system equivalence method, comprising:
determining a first bus node which needs to be reserved by the power system;
performing multi-port Thevenin equivalence on the first bus bar node to obtain equivalent self-impedance of the first bus bar node;
performing static equivalence on the first bus node to obtain an equivalent power source model of the first bus node;
calculating the variable impedance before the first bus node fails and the variable impedance after the first bus node fails according to the equivalent self-impedance of the first bus node;
according to the variable impedance before the first bus node fails and the variable impedance after the first bus node fails, converting the equivalent power model after the first bus node is statically equivalent into a pre-fault equivalent power model consisting of an ideal voltage source and the variable impedance before the first bus node fails and a post-fault equivalent power model consisting of the ideal voltage source and the variable impedance after the first bus node fails;
the equivalent self-impedance comprises a first equivalent self-impedance and a second equivalent self-impedance; the multi-port Thevenin equivalence of the first busbar node to obtain the equivalent self-impedance of the first busbar node comprises:
when a genset in the power system employs an "invariant model", performing multi-port thevenin equivalence on the first busbar node to obtain a first equivalence self-impedance Z "of the first busbar node;
when generating set in the electric power system adopts an E 'constant model, it is right that the first busbar node is subjected to multiport Thevenin equivalence and is obtained the second equivalence of the first busbar node is from impedance Z'.
2. The method of claim 1, wherein calculating the variable impedance before the first bus node fault and the variable impedance after the first bus node fault from the equivalent self-impedance of the first bus node comprises:
taking the first equivalent self-impedance Z' of the first bus node as the variable impedance Z before the first bus node failsFront side；
The variable impedance after the first bus node fault is calculated according to the following formula:
Zrear end＝Z”+(Z'-Z”)*e-αt；
Wherein, Z isRear endAnd the variable impedance is the variable impedance after the first bus node is in fault, alpha is a decay time constant, and t is fault time.
3. The equivalent device of the power system is characterized by comprising a judgment module, a processing module and an equivalent module;
the judging module is used for determining a first bus node which needs to be reserved by the power system;
the processing module is used for carrying out multi-port Thevenin equivalence on the first bus node determined by the judging module so as to obtain equivalent self-impedance of the first bus node;
the equivalence module is used for carrying out static equivalence on the first bus node determined by the judgment module so as to obtain a first equivalence power model of the first bus node;
the processing module is further used for calculating the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node according to the equivalent self-impedance of the first bus node;
the processing module is further used for converting the equivalent power source model after the static equivalence of the first bus node into a pre-fault equivalent power source model consisting of an ideal voltage source and the variable impedance before the fault of the first bus node and a post-fault equivalent power source model consisting of the ideal voltage source and the variable impedance after the fault of the first bus node according to the variable impedance before the fault of the first bus node and the variable impedance after the fault of the first bus node;
the equivalent self-impedance comprises a first equivalent self-impedance and a second equivalent self-impedance; the processing module is specifically configured to:
when a genset in the power system employs an "invariant model", performing multi-port thevenin equivalence on the first busbar node to obtain a first equivalence self-impedance Z "of the first busbar node;
when generating set in the electric power system adopts an E 'constant model, it is right that the first busbar node is subjected to multiport Thevenin equivalence and is obtained the second equivalence of the first busbar node is from impedance Z'.
4. The apparatus of claim 3, wherein the processing module is specifically configured to:
taking the first equivalent self-impedance Z' of the first bus node as the variable impedance Z before the first bus node failsFront side；
The variable impedance after the first bus node fault is calculated according to the following formula:
Zrear end＝Z”+(Z'-Z”)*e-αt；
Wherein, Z isRear endAnd the variable impedance is the variable impedance after the first bus node is in fault, alpha is a decay time constant, and t is fault time.
5. A computer-readable storage medium containing one or more programs which, when executed by a computer, cause the computer to perform the power system equivalence method according to any one of claims 1-2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711247673.7A CN109873415B (en) | 2017-12-01 | 2017-12-01 | Equivalent method and device for power system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711247673.7A CN109873415B (en) | 2017-12-01 | 2017-12-01 | Equivalent method and device for power system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109873415A CN109873415A (en) | 2019-06-11 |
| CN109873415B true CN109873415B (en) | 2020-12-25 |
Family
ID=66914503
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711247673.7A Active CN109873415B (en) | 2017-12-01 | 2017-12-01 | Equivalent method and device for power system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109873415B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112685981B (en) * | 2020-12-28 | 2024-05-07 | 南方电网科学研究院有限责任公司 | Static equivalence method and device for power system, terminal equipment and storage medium |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101505061A (en) * | 2009-03-17 | 2009-08-12 | 中国电力科学研究院 | Computation method capable of tracking Davinan equivalence parameter base on time domain simulation |
| CN101562332A (en) * | 2009-05-27 | 2009-10-21 | 天津大学 | Self-adaptive current fast tripping protection method for distribution network comprising inverse distributed power |
| CN102693358A (en) * | 2012-04-18 | 2012-09-26 | 中国电力科学研究院 | Tracking and computing method of Thevenin equivalent of full-dynamic process power system |
| CN103809079A (en) * | 2014-02-17 | 2014-05-21 | 华北电力大学 | Double-end high frequency impedance type fault ranging method suitable for direct current distribution network |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101383511B (en) * | 2008-10-10 | 2010-08-04 | 清华大学 | Electrical power system status estimation method based on measurement data by data collection system |
-
2017
- 2017-12-01 CN CN201711247673.7A patent/CN109873415B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101505061A (en) * | 2009-03-17 | 2009-08-12 | 中国电力科学研究院 | Computation method capable of tracking Davinan equivalence parameter base on time domain simulation |
| CN101562332A (en) * | 2009-05-27 | 2009-10-21 | 天津大学 | Self-adaptive current fast tripping protection method for distribution network comprising inverse distributed power |
| CN102693358A (en) * | 2012-04-18 | 2012-09-26 | 中国电力科学研究院 | Tracking and computing method of Thevenin equivalent of full-dynamic process power system |
| CN103809079A (en) * | 2014-02-17 | 2014-05-21 | 华北电力大学 | Double-end high frequency impedance type fault ranging method suitable for direct current distribution network |
Non-Patent Citations (2)
| Title |
|---|
| PCC点***侧戴维南等值电路参数的估计方法研究;张坤 等;《电工电能新技术》;20170430;第36卷(第4期);7-15 * |
| 基于WAMS测量和戴维南等值的电力***动态仿真误差溯源及可信度验证方法;安军 等;《电网技术》;20130531;第37卷(第5期);1389-1394 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109873415A (en) | 2019-06-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Gozel et al. | Optimal placement and sizing of distributed generation on radial feeder with different static load models | |
| Jiang et al. | An efficient PMU-based fault-location technique for multiterminal transmission lines | |
| CN107342586B (en) | Method and device for determining static equivalence of power distribution network | |
| Manassero et al. | Heuristic method for fault location in distribution feeders with the presence of distributed generation | |
| CN111914205B (en) | Method and device for calculating theoretical line loss of transformer area and daily load curve calculation method | |
| US20210397762A1 (en) | Distribution grid admittance estimation with limited nonsynchronized measurements | |
| Bagheri‐Vandaei et al. | Generalised extended‐frequency dynamic phasor model of LCC‐HVDC systems for electromagnetic transient simulations | |
| CN104992017A (en) | Wind power random fluctuation based generalized load modeling method and apparatus | |
| Patsalides et al. | Simplified distribution grid model for power quality studies in the presence of photovoltaic generators | |
| Cai et al. | A threshold free synchrophasor measurement based multi-terminal fault location algorithm | |
| Benato | A basic AC power flow based on the bus admittance matrix incorporating loads and generators including slack bus | |
| Furlaneto et al. | Short circuit network equivalents of systems with inverter-based resources | |
| Nakhodchi et al. | Transfer of harmonics in distribution networks | |
| CN104142419B (en) | Power grid short-circuit current acquiring method with influences of loads considered | |
| CN109873415B (en) | Equivalent method and device for power system | |
| Parihar et al. | Power flow analysis of balanced radial distribution system with composite load model | |
| Hartmann et al. | Development of steady state and dynamic energy storage models for DIgSILENT PowerFactory | |
| Vieira et al. | Harmonic studies in OpenDSS considering renewable DG and aggregate linear load models | |
| Gautam et al. | A methodology for power flow & voltage stability analysis | |
| CN108649596B (en) | Battery energy storage system dynamic model suitable for load modeling | |
| CN106785708B (en) | A kind of socket and its line management method | |
| Kocar et al. | Nonlinear network equivalents of systems with inverter based resources to study unbalanced faults in steady state | |
| Fonseca et al. | Loadability analysis based on short‐circuit power | |
| Dufour et al. | Renewable integration and protection studies on a 750-node distribution grid using a real-time simulator and a delay-free parallel solver | |
| Zhou et al. | Research on µPMU based fault location for active distribution network |
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 |