CN111509703A - Power distribution network loop closing and power adjusting operation decision method and system - Google Patents
Power distribution network loop closing and power adjusting operation decision method and system Download PDFInfo
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- H—ELECTRICITY
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- 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
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Abstract
The application relates to the technical field of power distribution network operation, in particular to a power distribution network loop closing and power adjusting operation decision method and system. The application provides a power distribution network loop closing and power switching operation decision method, which comprises the following steps: constructing a power distribution network equipment basic database; establishing a hybrid simulation calculation model according to a real-time operation mode of a power grid, wherein the hybrid simulation calculation model comprises an electromechanical transient simulation model and a closed-loop operation local electromagnetic transient model; performing hybrid simulation calculation based on the electromechanical transient simulation model and the closed-loop operation local electromagnetic transient model, and outputting a hybrid simulation calculation result; performing preliminary decision making based on the hybrid simulation calculation result and a power distribution network equipment basic database; and carrying out multi-index comprehensive decision on the preliminary decision to obtain a final decision.
Description
Technical Field
The application relates to the technical field of power distribution network operation, in particular to a power distribution network loop closing and power adjusting operation decision method and system.
Background
With the development of power distribution networks, the power supply modes of bidirectional power supply and multi-power supply of a power distribution network are increasing. When a certain bus, switch or feeder needs to be overhauled or has a fault, the load supplied by multiple power supplies on the bus, switch or feeder can be transferred to other buses or feeders connected with the load through loop closing operation, so that the load is reversed without power failure, namely loop closing and power adjusting are realized. The loop closing power transfer can reduce the power failure time of users, improve the reliability of power supply, ensure the power supply quality of the system and improve the satisfaction degree of the public to the power service. Along with the increase of the power load density, the power grid structure is increasingly complex, double power supplies and even multiple power supplies are more and more supplied, and the trend of realizing the load reversal without power outage through the ring closing and opening operation is inevitable.
When the substations belonging to two different sub-areas carry out loop closing and power dispatching, risks such as equipment overload, relay protection misoperation, short circuit current exceeding standard, accident expansion caused by an electromagnetic looped network and the like caused by overlarge loop closing current can occur under the influence of system operation conditions and power grid parameters, and the safety of a power grid is influenced. Namely, the main problem brought by the loop closing operation is that due to the fact that a certain voltage phase difference exists between the buses on the two sides of the loop closing switch or the interconnection switch before the loop closing, an overlarge loop closing current is possibly generated in the loop closing operation, so that the misoperation of quick-break protection or overcurrent protection is caused, the power failure area is enlarged, and the adverse effect is caused. In this case, although before the loop closing operation, the system load flow calculation is generally performed, and the feasibility of the loop closing operation is evaluated according to the tolerance degree of the primary and secondary devices.
The closed loop feasibility evaluation is firstly mainly carried out by depending on long-term actual operation management experience and combining with field test data, the work of a system load flow calculation part is added, and the comprehensive evaluation is carried out by referring to the calculation result. The evaluation scheme excessively depends on empirical judgment, and the evaluation on the closed-loop power-transfer feasibility is easy to have errors. Meanwhile, due to the influence of simulation boundary conditions, the fact that a model cannot be checked and the like, accuracy of offline system load flow calculation cannot be guaranteed, identification granularity of distribution network current is not enough based on load flow calculation performed by electromechanical transient simulation software such as BPA, overcurrent conditions of all key equipment cannot be reflected comprehensively, and the like directly influence closed loop evaluation results. Moreover, at present, no decision system with better integration level exists in analysis work of closed-loop power conditioning, and economic calculation results are needed to perform manual analysis on adaptability of primary and secondary equipment to a running mode after closed-loop, so that early preparation work of closed-loop power conditioning is invisibly increased.
Disclosure of Invention
The application provides a power distribution network loop closing and power regulating operation decision method and a system, wherein a basic database of power distribution network loop closing operation equipment is established, transient state and steady state calculation of loop closing operation is carried out on the basis of a hybrid simulation technology of electromechanical transient state and electromagnetic transient state, settlement results and basic data are combined, indexes such as tolerance degree, load rate and influence on system operation modes and loss of the equipment are comprehensively evaluated, an optimal loop closing and power regulating scheme is searched, and a final decision result is formed.
The embodiment of the application is realized as follows:
in a first aspect of the embodiments of the present application, a power distribution network loop closing and power switching operation decision method is provided, where the method includes
Constructing a power distribution network equipment basic database;
establishing a hybrid simulation calculation model according to a real-time operation mode of a power grid, wherein the hybrid simulation calculation model comprises an electromechanical transient simulation model and a closed-loop operation local electromagnetic transient model;
performing hybrid simulation calculation based on the electromechanical transient simulation model and the closed-loop operation local electromagnetic transient model, and outputting a hybrid simulation calculation result;
performing preliminary decision making based on the hybrid simulation calculation result and a power distribution network equipment basic database;
and carrying out multi-index comprehensive decision on the preliminary decision to obtain a final decision.
A second aspect of the embodiments of the present application provides a power distribution network loop closing and power dispatching operation decision system, including:
the power distribution network equipment basic database is configured to be used for setting rated parameters, equipment overload capacity and mechanical performance parameters of equipment;
a hybrid simulation calculation module configured for electromechanical transient calculation and electromagnetic transient calculation, including electrical simulation calculation mainly for ring closing points, including common PSS/E-based combined PSCAD hybrid simulation, as well as ADPSS-based hybrid simulation and other electromechanical and electromagnetic hybrid simulation;
the comprehensive scheme evaluation module is configured to mainly complete comprehensive evaluation of the closed-loop scheme, and comprises feasibility judgment of the scheme and optimal decision of the multiple closed-loop scheme;
and the decision result generation module is configured to mainly generate intermediate reports of the decision process, including an electromagnetic transient calculation report, an electromechanical transient calculation report, a load flow calculation report and a final decision report.
The beneficial effect of this application lies in: the method comprises the steps of constructing a basic database of distribution network loop closing operation equipment, performing transient state and steady state calculation of loop closing operation based on a hybrid simulation technology of electromechanical transient state and electromagnetic transient state, comprehensively evaluating indexes such as tolerance degree and load rate of the equipment, influence on system operation mode, loss and the like by combining settlement results and basic data, searching for an optimal loop closing and power regulating scheme, and forming a final decision result.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.
Fig. 1 is a schematic flowchart illustrating a power distribution network loop closing and power switching operation decision method according to an embodiment of the present application;
fig. 2 shows a power distribution network closed loop power-transfer operation decision system according to an embodiment of the present application.
Detailed Description
To make the objects, technical solutions and advantages of the exemplary embodiments of the present application clearer, the technical solutions in the exemplary embodiments of the present application will be clearly and completely described below with reference to the drawings in the exemplary embodiments of the present application, and it is obvious that the described exemplary embodiments are only a part of the embodiments of the present application, but not all the embodiments.
All other embodiments, which can be derived by a person skilled in the art from the exemplary embodiments shown in the present application without inventive step, are within the scope of protection of the present application. Moreover, while the disclosure herein has been presented in terms of exemplary one or more examples, it is to be understood that each aspect of the disclosure can be utilized independently and separately from other aspects of the disclosure to provide a complete disclosure.
It should be understood that the terms "first," "second," "third," and the like in the description and in the claims of the present application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used are interchangeable under appropriate circumstances and can be implemented in sequences other than those illustrated or otherwise described herein with respect to the embodiments of the application, for example.
Furthermore, the terms "comprises" and "comprising," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a product or device that comprises a list of elements is not necessarily limited to those elements explicitly listed, but may include other elements not expressly listed or inherent to such product or device.
The term "component" as used herein refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and/or software code that is capable of performing the functionality associated with that element.
In this application, the term "distribution network" is short for a distribution network.
Reference throughout this specification to "embodiments," "some embodiments," "one embodiment," or "an embodiment," etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in various embodiments," "in some embodiments," "in at least one other embodiment," or "in an embodiment," or the like, throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics shown or described in connection with one embodiment may be combined, in whole or in part, with the features, structures, or characteristics of one or more other embodiments, without limitation. Such modifications and variations are intended to be included within the scope of the present application.
The method mainly depends on basic data and a hybrid simulation calculation result, and combines a reasonable multi-target evaluation method to form a decision scheme of closed-loop power conditioning. The specific implementation flow chart is as follows.
Fig. 1 shows a flow chart of a power distribution network closed loop power transfer operation decision method according to an embodiment of the present application.
In step 101, a power distribution network equipment base database is constructed.
In some embodiments, a power distribution network equipment basic database is established as required, the work is required to be carried out before each loop closing operation evaluation, and then the work can be carried out without the need of being carried out after the regional or whole network database is completed, wherein the basic database is a gradually completed process.
The power distribution network equipment basic database comprises basic parameters of primary equipment and setting configuration parameters of a control protection secondary system of the primary equipment; the primary equipment is one or a plurality of combinations of distribution network switch equipment, distribution transformers and distribution lines.
The basic data of the distribution network equipment mainly refers to basic parameters (including short-circuit current bearing capacity, overload capacity and the like) such as primary equipment of distribution network switch equipment, distribution transformers, distribution lines and the like, rated parameters of the basic equipment and the like, and secondary system setting configuration conditions such as control protection and the like. The basic database is required to be newly built before each loop closing operation evaluation, and then the basic database can be unnecessary to be developed after the regional or whole network database is completed, and the basic database is a gradually completed process.
The distribution network is an electric power network which receives electric energy from a transmission network or a regional power plant and distributes the electric energy to various users on site through distribution facilities or step by step according to voltage. The power distribution network is composed of overhead lines, cables, towers, distribution transformers, isolating switches, reactive power compensators, a plurality of accessory facilities and the like, and plays a role in distributing electric energy in the power network.
The grid voltage class can be generally divided into:
extra-high voltage (1000kV alternating current and above and +/-800 kV direct current), extra-high voltage (330kV and above to below 1000 kV), high voltage (35-220 kV), medium voltage (6-20 kV) and low voltage (0.4 kV).
According to the voltage class of the distribution system in China, according to the regulation of (Q/GDW 156-2006) urban power grid planning and design guide rule, 35kV, 63kV and 110kV are high-voltage distribution systems; 6 kV-10 kV (20kV) is a medium-voltage distribution system; 220V (380V) is a low-voltage distribution system. The classification of the distribution network is then as follows:
according to voltage class classification, the distribution network can be divided into: a high-voltage distribution network (6-110 kV); low-voltage distribution network (0.4 kV).
According to the regional classification of power supply, the distribution network can be divided into: an urban power distribution network; a rural power distribution network; a power distribution network of a factory.
According to the electric wire netting function classification, the distribution network can divide into: a main network (66kV and above); distribution network (35kV and below).
The main role of the 66kV (110kV) grid is to connect regional high voltage (220kV and above) grids. The distribution network of 35kV or below is mainly used for providing power supply for each distribution station and various users. High-voltage users with voltage class of 10kV and above are directly powered by a high-voltage distribution device of a power supply (rural power) transformer substation and a special line of the high-voltage users.
In step 102, a hybrid simulation calculation model is established according to the real-time operation mode of the power grid, wherein the hybrid simulation calculation model comprises an electromechanical transient simulation model and a closed loop operation local electromagnetic transient model.
The hybrid simulation calculation model is based on the network architecture, the operation mode and the basic equipment parameters of the actual distribution network. The method comprises the following steps of establishing an electromechanical transient simulation model and a loop closing point electromagnetic transient model, wherein the electromechanical transient simulation model and the loop closing operation local electromagnetic transient model are mainly established according to the network architecture, the operation mode and basic equipment parameters of an actual distribution network.
In some embodiments, a data interaction interface may be further provided in a hybrid simulation calculation program used by the hybrid simulation calculation model, and the data interaction interface is compatible with the power distribution network basic database.
With the development of computer and electronic technology, it has become possible to simulate system faults by using numbers and to change transient digital simulation results into real waveform outputs. The electromagnetic transient model is used for simulating system faults and is applied to accident analysis of the field protection device.
Loop closing refers to the operation of closing a network of lines, transformers or breaker strings in operation in an electrical power system.
According to the dispatching regulation of the power system, the power grid running in a subarea should meet three conditions of 'correct phase under the same system and voltage difference within 20%' during loop closing, and generally has the following basic operation rules:
definitely knowing that the loop closing and opening systems belong to the same system, and roughly mastering the tide after loop closing;
knowing the network condition of the previous stage, especially when the network governed by the previous stage scheduling is involved, the network should obtain the agreement about the scheduling;
knowing the voltage conditions of the systems on the two sides, and considering the phase angle difference and the voltage difference on the two sides of the loop closing point so as to ensure that the change of the tide current during loop closing does not cause relay protection action;
in a system with the arc suppression coil grounded, the correct operation of the arc suppression coil after the ring is closed or opened should be considered;
a switch is used for carrying out ring closing and opening operation, and the change of the tide during ring closing is considered in the ring closing operation. The method can be estimated according to the operation condition and network parameters of the previous-stage network, the low-voltage side bus differential pressure participating in loop closing, the original tide condition and the operation experience. If the estimated trend is large and the overcurrent action is likely to be caused, the following measures can be taken:
disabling the possible protection;
setting a disconnection point (the fixed value can be changed when necessary) on a switch with a preset disconnection, and informing a substation attendant to pay attention to the current change and the protection action condition;
the voltage difference of two low-voltage side buses participating in ring closing is adjusted to be minimum, the maximum voltage difference does not exceed 10% during normal ring closing and opening operation, 35kV is generally not suitable to exceed 15% during accident handling, and 110kV or more is not suitable to exceed 20%;
if the pressure difference is larger and the estimated circulation is larger, the circulation can be reduced by changing system parameters, and the situation that the voltage on the heavy load side is higher than that on the light load side is more can be avoided as much as possible.
When the complex loop closing and opening operation of the two systems is carried out and no operation experience exists, the load flow calculation is preferably carried out firstly.
In some embodiments, the closed-loop operation local electromagnetic transient model is adjusted, embodied as modifying an electromechanical transient portion that requires simulation computation in an electromagnetic transient, and a hybrid simulation interface is provided.
In step 103, hybrid simulation calculation is performed based on the electromechanical transient simulation model and the closed loop operation local electromagnetic transient model, and a hybrid simulation calculation result is output.
And carrying out hybrid simulation calculation based on the electromechanical transient simulation model and the closed-loop operation local electromagnetic transient model.
In some embodiments, the hybrid simulation calculation result includes transient and steady electrical quantities of the switching devices, the transformer devices and the line devices in a preset area near the ring closing point; and the switching value is used for representing the action conditions of secondary equipment such as relay protection.
The output of this work is a result of hybrid simulation calculation, which mainly includes the transient and steady state electrical quantities of the switching devices, the transformer devices, and the line devices in the preset area near the ring-closing point and the switching quantities reflecting the relay protection action signals, and is expressed as: u1, I1, P1, U2, I2, P2, U3, I3, P3, a.
The method of hybrid simulation calculation model can integrate the advantages of fast calculation speed of analog computer and high calculation precision of digital computer, the hybrid simulation method related by this case is the mutual combination and complement of electromechanical transient simulation and electromagnetic transient simulation, and is a pure digital simulation with multiple time scales, large power grid data is calculated by electromechanical transient, loop closing operation local power grid is calculated by electromagnetic detailed model, and the real power grid is restored to the maximum, and a large amount of equivalent work is omitted, the key problem of hybrid simulation method is to reasonably distribute tasks and properly select frame rate for two different computers, the distribution of tasks depends mainly on the nature of tasks and the requirements for precision and speed, the selection of frame rate is that ① the maximum effective frequency of signals including interference must be less than half of sampling frequency according to sampling theorem, ② amplitude and phase errors caused by time delay and zero order hold must be limited within the allowable range, and ③ the truncation error of numerical calculation must be ignored for the simulated system.
In step 104, a preliminary decision is made based on the hybrid simulation calculation result and the power distribution network equipment basic database.
The preliminary decision making includes directly negating feasibility of the preliminary decision if the switching value representing the action conditions of secondary equipment such as equipment relay protection is changed from 0 to 1; and otherwise, if the preliminary decision is a feasible scheme, and if more feasible schemes exist, performing comprehensive evaluation.
In some embodiments, the switch in the digital circuit has two states of 1 and 0, and the power refers to the on and off of the circuit or the connection and disconnection of the contacts, "on" and "off" are the most basic and typical functions of the electric appliance.
In step 105, a multi-index comprehensive decision is performed on the preliminary decision to obtain a final decision.
Carrying out multi-index comprehensive decision on the preliminary decision, and directly negating the feasibility of the preliminary decision if the comprehensive decision does not meet the requirements; and if the comprehensive decision is a feasible scheme, carrying out comprehensive decision on the method for assigning the evaluation indexes according to the management requirements, and searching for an optimal scheme.
The multiple indexes specifically include equipment overvoltage level, equipment load rate, equipment loss and system operation influence.
The comprehensive decision is specifically implemented by introducing weight coefficients into the indexes, assigning the weight coefficients according to production management requirements, calculating comprehensive decision values of feasible schemes and searching for an optimal scheme. In some embodiments, the weight coefficients are introduced into the indexes, and the weight coefficients can be assigned by artificial subjectivity and reference experience according to production management requirements, so as to calculate a comprehensive decision value of each feasible scheme.
In some embodiments, the multiple indicators specifically include at least one of equipment overvoltage level, equipment load factor, equipment loss, and system operation impact. In some embodiments, the load factor λ and the loss Pe may be directly calculated by a formula. A load refers to an electronic component connected across a power source in a circuit. The circuit should not have a load but directly connect the two poles of the power supply, and this connection is called a short circuit. Common loads are resistors, power consuming components such as engines and light bulbs. The device that converts electrical energy to another form of energy is called a load. The motor can convert electric energy into mechanical energy, the resistor can convert electric energy into heat energy, the light bulb can convert electric energy into heat energy and light energy, and the loudspeaker can convert electric energy into sound energy. Motors, resistors, light bulbs, speakers, etc. are all referred to as loads. The transistor can also be considered as a load for the previous signal source. The most basic requirements for the load are impedance matching and power that can be tolerated. The load factor in the index may be actually considered to be an indication of the degree of tolerance.
The rated short-time withstand current, also called thermally stable current, is an effective value of current that a circuit breaker or other equipment can withstand in a predetermined short time. Its magnitude is equal to the rated short circuit current, and the time is generally 3 seconds or 4 seconds. Short-time withstand current (Icw) refers to the ability to withstand 0.05, 0.1, 0.25, 0.5, or 1s at a certain voltage, short circuit current, power factor without allowing the circuit breaker to trip. Icw is an assessment index for the electric stability and thermal stability of the breaker when tripping with short delay, it is for the type B breaker, usually the minimum value of Icw is: when in.ltoreq.2500A, it is 12In or 5kA, and when In >2500A, it is 30 kA.
In some embodiments, the system operation impact T primarily takes into account the impact on relay protection as well as the impact of short circuit current changes.
The influence of the former is expressed by a switching value, if protection misoperation is caused, the scheme is considered to be impossible to change, and the influence on the short-circuit current is evaluated by introducing an entropy weight method according to the increase degree of the short-circuit current.
The relay protection is an important measure for detecting faults or abnormal conditions occurring in the power system so as to send out alarm signals or directly isolate and remove fault parts.
According to the explanation of the basic principle of information theory, information is a measure of the degree of system order, and entropy is a measure of the degree of system disorder; if the larger the information entropy of the index is, the larger the information amount provided by the index is, the larger the role played in the comprehensive evaluation is, and the higher the weight should be. Therefore, the weight of each index can be calculated by using the information entropy tool, and a basis is provided for multi-index comprehensive evaluation.
In classical thermodynamics, the increment can be defined as dS (dQ/T), where T is the thermodynamic temperature of the substance, dQ is the heat added to the substance during entropy increase, the subscript "reversible" indicates that the process of change caused by the heating process is reversible, if the process is irreversible, dS > (dQ/T) is irreversible, the entropy per mass of the substance is called specific entropy, which is a substance state parameter that reflects the irreversible nature of the spontaneous process, which is derived from the second law of thermodynamics in which ① heat is always transferred from the high temperature object to the low temperature object, without the possibility of an opposite transfer causing other changes, ② work can be entirely converted into heat, but any heat engine cannot be used to continuously convert the accepted heat into continuous work (i.e. to make a second type of motive power), in which the entire system, the heat transfer system can be increased permanently by increasing the total entropy of the heat transferred from the high temperature object to the low temperature object 3527, i.e. the entire heat transfer system can be increased by increasing T < 9 > T < T > T < 9 > T < T > T < T > T < T > T < T > T < T > T <.
Fig. 2 shows a power distribution network closed loop power-transfer operation decision system according to an embodiment of the present application.
The power distribution network closed loop power transfer operation decision system mainly comprises: the system comprises a power distribution network equipment basic database 201, a hybrid simulation calculation module 202, a scheme comprehensive evaluation module 203 and a decision result generation module 204. The following describes each module separately:
the power distribution network equipment basic database 201 is configured to be used for setting thermal performance and mechanical performance parameters such as rated parameters and equipment overload capacity of equipment.
The method is particularly used for establishing basic data of the power distribution network equipment, and mainly comprises overload capacities such as rated parameters, short-circuit current bearing capacity and the like of basic equipment such as switching equipment, distribution transformers, distribution lines and the like. The data are collected and mainly used for electromagnetic transient modeling of equipment on an electrical node of closed-loop power-conditioning operation, and multi-index evaluation calculation is carried out by combining a hybrid simulation result.
The method has the advantages that the large amount of basic data of the power distribution network is considered, the complete basic database is established, and the workload is large. The network position of the operating point of the closed loop can be considered, and the completion is carried out in stages. Specifically, only two levels of distribution network equipment data above and below the ring-closing point need to be considered at each stage, including one level or multiple levels above and below.
A hybrid simulation calculation module 202 configured for electromechanical transient calculation and electromagnetic transient calculation, including electrical simulation calculation mainly for ring closing points, including common PSS/E joint PSCAD based hybrid simulation, as well as ADPSS based hybrid simulation and other electromechanical and electromagnetic hybrid simulations.
At present, an electromechanical transient model is generally adjusted locally based on an existing data model, electromagnetic transient modeling is performed on a node needing to carry out loop closing operation, and a detailed electromagnetic transient model is used for replacing the electromechanical model and comprises a switch model, a circuit model, a secondary equipment model such as a control and protection model, a load model and the like, so that the electromagnetic transient calculation accuracy of the loop closing operation is improved.
The scheme comprehensive evaluation module 203 is configured to mainly perform comprehensive evaluation of the closed-loop scheme, including feasibility judgment of the scheme and optimal decision of the multiple-closed-loop scheme.
And a hybrid simulation calculation module is adopted to provide an interface for interaction schemes such as a loop closing scheme decision module and distribution network basic database data fetching, and calculation data is provided for a comprehensive evaluation module.
The specific evaluation method comprises the step of carrying out multi-index comprehensive decision making such as equipment overvoltage level, equipment load rate, equipment loss, system operation influence and the like.
And evaluating multiple assessment targets according to the mixed simulation calculation result and the basic database, wherein the specific targets comprise an equipment overvoltage level α, an equipment load rate lambda, an equipment loss Pe, a system operation influence T and the like.
The device overvoltage level α, the device load factor λ, and the device loss Pe can be directly calculated by formulas.
The system operation influence mainly comprises: the influence on the relay protection action and the influence on the change of the short-circuit current. The influence of the former is expressed by switching value (obtained by simulation), if protection misoperation is caused, the scheme is considered to be impossible to change, and the influence of the short-circuit current is considered to be evaluated by introducing an entropy weight method according to the increase degree of the short-circuit current.
And (4) performing multi-index comprehensive decision, and directly negating the feasibility if the evaluation in the previous link does not meet the requirement. And for a feasible scheme, carrying out comprehensive decision making by a method of carrying out artificial subjective assignment on each evaluation index according to the management requirement, and searching for an optimal scheme.
The decision result generation module 204 is configured to mainly generate intermediate reports of the decision process, including electromagnetic transient calculation reports, electromechanical transient calculation reports, load flow calculation reports, and final decision reports.
The beneficial effect of this application lies in: the method comprises the steps of constructing a basic database of distribution network loop closing operation equipment, performing transient state and steady state calculation of loop closing operation based on a hybrid simulation technology of electromechanical transient state and electromagnetic transient state, comprehensively evaluating indexes such as equipment overvoltage level, equipment load rate, system operation influence and equipment loss by combining settlement results and basic data, searching for an optimal loop closing and power adjusting scheme, and forming a final decision result.
Moreover, those skilled in the art will appreciate that aspects of the present application may be illustrated and described in terms of several patentable species or situations, including any new and useful combination of processes, machines, manufacture, or materials, or any new and useful improvement thereon. Accordingly, various aspects of the present application may be embodied entirely in hardware, entirely in software (including firmware, resident software, micro-code, etc.) or in a combination of hardware and software. The above hardware or software may be referred to as "data block," module, "" engine, "" unit, "" component, "or" system. Furthermore, aspects of the present application may be represented as a computer product, including computer readable program code, embodied in one or more computer readable media.
The computer storage medium may comprise a propagated data signal with the computer program code embodied therewith, for example, on baseband or as part of a carrier wave. The propagated signal may take any of a variety of forms, including electromagnetic, optical, etc., or any suitable combination. A computer storage medium may be any computer-readable medium that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code located on a computer storage medium may be propagated over any suitable medium, including radio, cable, fiber optic cable, RF, or the like, or any combination of the preceding.
Computer program code required for operation of various portions of the present application may be written in any one or more programming languages, including AN object oriented programming language such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C + +, C #, VB.NET, Python, and the like, a conventional programming language such as C, VisualBasic, Fortran2003, Perl, COBO L2002, PHP, ABAP, a dynamic programming language such as Python, Ruby, and Groovy, or other programming languages, and the like.
Additionally, the order in which elements and sequences of the processes described herein are processed, the use of alphanumeric characters, or the use of other designations, is not intended to limit the order of the processes and methods described herein, unless explicitly claimed. While various presently contemplated embodiments of the invention have been discussed in the foregoing disclosure by way of example, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements that are within the spirit and scope of the embodiments herein. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described system on an existing server or mobile device.
Similarly, it should be noted that in the preceding description of embodiments of the application, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to require more features than are expressly recited in the claims. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.
The entire contents of each patent, patent application publication, and other material cited in this application, such as articles, books, specifications, publications, documents, and the like, are hereby incorporated by reference into this application. Except where the application is filed in a manner inconsistent or contrary to the present disclosure, and except where the claim is filed in its broadest scope (whether present or later appended to the application) as well. It is noted that the descriptions, definitions and/or use of terms in this application shall control if they are inconsistent or contrary to the statements and/or uses of the present application in the material attached to this application.
Claims (10)
1. A power distribution network loop closing and power dispatching operation decision method is characterized by comprising
Constructing a power distribution network equipment basic database;
establishing a hybrid simulation calculation model according to a real-time operation mode of a power grid, wherein the hybrid simulation calculation model comprises an electromechanical transient simulation model and a closed-loop operation local electromagnetic transient model;
performing hybrid simulation calculation based on the electromechanical transient simulation model and the closed-loop operation local electromagnetic transient model, and outputting a hybrid simulation calculation result;
performing preliminary decision making based on the hybrid simulation calculation result and a power distribution network equipment basic database;
and carrying out multi-index comprehensive decision on the preliminary decision to obtain a final decision.
2. The power distribution network loop closing and switching operation decision method as claimed in claim 1,
the power distribution network equipment basic database comprises basic parameters of primary equipment and secondary system setting configuration parameters;
the secondary system setting configuration parameters are used for control protection of the primary equipment;
the primary equipment is one or a plurality of combinations of distribution network switch equipment, distribution transformers and distribution lines.
3. The power distribution network loop closing and switching operation decision method according to claim 1, wherein the hybrid simulation calculation model is based on a network architecture, an operation mode and basic equipment parameters of an actual distribution network.
4. The power distribution network loop closing and power dispatching operation decision method as claimed in claim 1, wherein the hybrid simulation calculation program of the hybrid simulation calculation model is provided with a data interaction interface, and the data interaction interface is compatible with the power distribution network equipment basic database.
5. The power distribution network loop closing and switching operation decision method according to claim 1, wherein the hybrid simulation calculation result comprises:
presetting transient and steady electrical quantities of regional switch equipment, transformer equipment and line equipment near a ring closing point; and the switching value representing the action conditions of secondary equipment such as relay protection and the like.
6. The power distribution network loop closing and power dispatching operation decision method according to claim 1, wherein the preliminary decision is made based on the hybrid simulation calculation result, and specifically comprises:
if the switching value representing the action conditions of secondary equipment such as equipment relay protection and the like is changed from 0 to 1, directly negating the feasibility of the preliminary decision;
and otherwise, if the preliminary decision is a feasible scheme, and if the feasible scheme is more, performing comprehensive evaluation.
7. The power distribution network loop closing and power dispatching operation decision method of claim 1, wherein the multi-index comprehensive decision, wherein:
the multiple indexes comprise: equipment overvoltage level, equipment load rate, equipment loss and system operation influence;
the comprehensive decision making specifically comprises the following algorithms: and introducing a weight coefficient into each index of the multiple indexes, assigning values to each weight coefficient according to production management requirements, and calculating a comprehensive decision value of each feasible scheme to obtain an optimal scheme.
8. A power distribution network closed loop power transfer operation decision system is characterized by comprising:
the power distribution network equipment basic database is configured to be used for setting rated parameters, equipment overload capacity and mechanical performance parameters of equipment;
a hybrid simulation calculation module configured for electromechanical transient calculation and electromagnetic transient calculation, including electrical simulation calculation mainly for ring closing points, including common PSS/E-based combined PSCAD hybrid simulation, as well as ADPSS-based hybrid simulation and other electromechanical and electromagnetic hybrid simulation;
the comprehensive scheme evaluation module is configured to mainly complete comprehensive evaluation of the closed-loop scheme, and comprises feasibility judgment of the scheme and optimal decision of the multiple closed-loop scheme;
and the decision result generation module is configured to mainly generate intermediate reports of the decision process, including an electromagnetic transient calculation report, an electromechanical transient calculation report, a load flow calculation report and a final decision report.
9. The system for decision making on power distribution network loop closing and dispatching operation of claim 8, wherein the power distribution network equipment basic database is constructed in a hierarchical manner according to the network location of the loop closing operation point, and the data of the distribution network equipment at two levels above and below the loop closing point are constructed, and comprise one level or multiple levels above and below the loop closing point.
10. The power distribution network loop closing and switching operation decision making system according to claim 8, wherein the scheme comprehensive evaluation module carries out a multi-index comprehensive decision of equipment overvoltage level, equipment load rate, equipment loss and system operation influence.
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