CN113659538A

CN113659538A - Distribution network intelligent setting method and system based on self-adaptive setting principle

Info

Publication number: CN113659538A
Application number: CN202110700669.1A
Authority: CN
Inventors: 邵庆祝; 汪伟; 谢民; 于洋; 俞斌; 张骏; 王吉文; 叶远波; 王栋; 丁津津; 孙辉
Original assignee: Electric Power Research Institute of State Grid Anhui Electric Power Co Ltd; State Grid Anhui Electric Power Co Ltd
Current assignee: Electric Power Research Institute of State Grid Anhui Electric Power Co Ltd; State Grid Anhui Electric Power Co Ltd
Priority date: 2021-06-23
Filing date: 2021-06-23
Publication date: 2021-11-16

Abstract

The invention discloses a distribution network intelligent setting method and system based on a self-adaptive setting principle, which comprises the steps of firstly obtaining the equivalence and fixed value quota issued by a main network to a distribution network, realizing the graphic modeling, setting calculation and fault analysis of a distribution network setting calculation system, reporting and verifying a generated electronic fixed value list and a calculation book, and transmitting the fixed value list to an OMS (operation management system) for circulation; and then automatically acquiring a power grid model of the distribution network for analysis, selecting an established setting scheme or establishing a setting scheme corresponding to a wiring mode according to the actual setting condition, realizing self-adaptation of setting principles under different grid structures and operation modes, and completing one-key setting of a principle level and a device level fixed value. The method realizes the self-adaptive matching of the setting principles under different network structures by establishing the setting principle expert libraries of different wiring types and topology analysis, and realizes the automatic setting of a fixed value on the basis of objective modeling; the technical problems of complex distribution network modeling and large workload are solved.

Description

Distribution network intelligent setting method and system based on self-adaptive setting principle

Technical Field

The invention relates to the technical field of power distribution networks, in particular to a power distribution network intelligent setting method and system based on a self-adaptive setting principle.

Background

The power distribution network is used as the last link of the power transmission and distribution system, and is closely related to a terminal power user, the safe and stable operation of the power distribution network is the guarantee of high quality and high reliable power consumption of the user, so the relay protection of the power distribution network which is used as the first defense line of the safe operation of the power distribution network is very important, and the following problems mainly exist in the aspect of setting calculation of the power distribution network at present:

(1) the power distribution network has huge equipment volume, complex wiring mode, more T wiring paths, large traditional graphic modeling setting workload and incapability of ensuring the accuracy of equipment parameters;

(2) the grid structure of the distribution network system equipment is complex, the operation mode changes frequently, the calculation principle of the current distribution network setting calculation principle is relatively extensive, a necessary checking means is lacked, the adaptability to the grid structure change is poor, and the safety of the fixed value is insufficient;

(3) the existing fixed value setting calculation system device is complex in modeling and cannot be well suitable for distribution network setting calculation, so that distribution network setting calculation work is mostly calculated manually, a fixed value is modified singly, manual intervention is more, the working efficiency is low, and errors are easy to occur;

(4) due to large-scale access of the distributed power supply, the traditional power supply of a single-side power supply is converted into the power supply of a double-end power supply or a multi-end power supply, so that the difficulty of relay protection constant value setting calculation is increased, the adaptability of the protection constant value is not strong, and the reliability level of power supply is reduced;

(5) the fixed value sheets are all papery files, so that the searching is very inconvenient and the unified management is difficult to realize.

In order to solve the problem of the current setting calculation situation of the power distribution network and improve the setting calculation efficiency of the power distribution network, a relay protection distribution network setting calculation system needs to be researched.

The setting calculation is an important component of relay protection work, and in power systems at home and abroad, setting calculation tools go through a low-level to high-level development stage. Reviewing the history of the application of computer technology in setting calculation, the setting calculation work can be divided into four times: before the seventies, setting calculation work is in the manual calculation era, and the setting calculation is mainly completed manually and assisted by a special calculation tool; starting from the seventies, the setting calculation of the protection fixed value is developed in the direction of utilizing a digital computer, and the setting calculation work enters an automatic age of short circuit calculation; in the early eighties, researchers develop research work of using a computer to perform relay protection setting calculation successively, and release a batch of setting calculation based on a DOS operating system, and the setting calculation work enters the batch task processing automation era; since the nineties, the development of computer software and hardware technologies is on the rise, and some new ideas, new methods and new technologies are gradually influencing the development of power system analysis software, such as the ideas of software engineering, programming methods of object-oriented and component-oriented technologies, artificial intelligence and adaptive technologies, database technologies and the like. Under the background of the times, the automation of the whole process of setting calculation is realized, a convenient and visual human-computer interaction interface is provided, and an organization management mode of data and information is perfected, so that the method becomes the development direction of the setting calculation software of a new generation.

At present, domestic power enterprises generally adopt computers to calculate relay protection setting values, the development and application of the software play an important role in improving the relay protection working level, but the problems of low networking degree of various types of software, unfriendly human-computer interaction interface, low automation degree of various types of analysis and calculation and the like occur in actual operation, the biggest problem is that the existing relay protection setting software is almost applied to a high-voltage power system above 110kV, and software developers mainly concentrate on the markets due to the consideration of economic benefits and do not develop the software for a power distribution network.

Currently, setting calculation software in the market is developed aiming at the characteristics of a high-voltage power system, but relay protection setting calculation of a high-voltage power grid and relay protection setting calculation of a power distribution network are not completely the same, because in the relay protection setting calculation of the power system, the power distribution network has certain differences in the aspects of parameter composition, network structure, setting mode and the like compared with the high-voltage power grid, and the existing relay protection setting software is generally expensive and cannot be borne by basic power enterprises.

Disclosure of Invention

The distribution network intelligent setting method based on the self-adaptive setting principle can solve the problem that distribution network setting calculation automation cannot be realized due to complex modeling and setting and the like of a distribution network.

In order to achieve the purpose, the invention adopts the following technical scheme:

a distribution network intelligent setting method based on a self-adaptive setting principle comprises the following steps:

firstly, obtaining the equivalence and the fixed value quota which are issued by a main network to a distribution network, realizing the graphic modeling, the setting calculation and the fault analysis of a distribution network setting calculation system, reporting and adjusting a generated electronic fixed value list and a calculation book for auditing, and then transmitting the fixed value list to an OMS system for streaming;

and then automatically acquiring a power grid model of the distribution network for analysis, selecting an established setting scheme or a setting scheme corresponding to a wiring mode according to the actual setting condition, realizing self-adaptation of setting principles under different grid structures and operation modes, and completing one-key setting of principle level and device level fixed values.

Further, the graphical modeling includes:

a power grid model data interface provided by a distribution network automation system imports a graph file containing a complete connection relation and a model file containing equipment parameters and topology connection into the system, and automatically generates a distribution network graph and a calculation model;

the distribution network graphics are displayed in a uniform and standard SVG format, and the display effect is consistent with the display effect of a power grid model in a distribution network automation system;

parameters such as line length, model and transformer model and capacity are obtained by analyzing the power grid model data file, reference parameters are obtained by automatically matching the equipment model according to a distribution network equipment parameter reference library, and then impedance parameters of each equipment are automatically calculated.

Further, the graphical modeling also comprises distribution network batch modeling;

the method comprises the following steps that a main line is automatically generated according to a set number of sections, branch lines are added to existing lines at will, cable distribution boxes, power distribution cabinets and ring network cabinets are added in batches, and extension branches are added to an existing power grid model of a distribution network;

the equipment connected with each branch in the cable distribution box, the power distribution cabinet and the ring main unit is set once to automatically generate a figure;

the distribution network tool box comprises all the devices of the distribution network and supports the random modification of the graphs.

Further, the graph modeling further comprises topology generation and graph generation;

the topology generation and graph generation comprises:

automatically generating a power distribution network graph in a standard SVG format for display by analyzing data topological connection; graphic element objects contained in the distribution network typical model correspond to the records of the database one by one, one record is automatically added in the database while one equipment primitive object is defined, attribute parameters and an input interface of the equipment primitives can be modified according to the requirements of a user, the one-to-one correspondence between the graphics and the database is achieved, and the compatibility of the system is ensured.

Further, the setting calculation includes,

firstly, setting original schemes corresponding to a primary switch and a secondary switch are established according to different wiring modes, the upper-lower stage relation of the switches configured with protection is automatically analyzed by analyzing received operation mode files, the corresponding setting principle schemes are matched, self-adaptation of the setting principles under different grid structures and operation modes is realized, then, fixed value calculation is carried out, and one-key setting of the fixed value of the device is completed.

Further, the selecting an established setting scheme or a setting scheme corresponding to a wiring mode according to an actual setting condition, realizing self-adaptation of setting principles under different grid structures and operation modes, and completing one-key setting of a principle level and a device level fixed value specifically comprises:

automatically scanning the operation mode file, acquiring the latest operation mode file of the outgoing line unit, comparing the latest operation mode file with the opening and closing of a switch in the current mode, and judging whether the operation mode file is changed or not, and finishing the operation if the operation mode file is not changed;

if the change is caused, according to a set rule, a primary switch and a secondary switch are determined according to the switch state and the topological connection of the configuration protection, the setting principle schemes corresponding to the primary switch and the secondary switch are automatically matched, the switch configured with the protection in the outgoing line unit carries out fixed value setting, the set fixed value is displayed in an interface, and finally a proposal scheme is generated according to the associated protection device.

Furthermore, a zero-level switch, a first-level switch and a second-level switch are shown in the proposal, and the fixed values of the switches are shown.

On the other hand, the invention also discloses a distribution network intelligent setting system with the self-adaptive setting principle, which comprises a distribution network relay protection self-adaptive setting calculation platform, a setting calculation system, a distribution network automation system/graph model management system and an OMS system, wherein the setting calculation system is respectively communicated with the distribution network relay protection self-adaptive setting calculation platform;

the method comprises the following steps that power grid data of a distribution network automation system/a graph model management system are adopted, and human intervention is carried out to ensure the correctness of distribution network model data; obtaining the equivalence and the fixed value quota issued by a setting calculation system, namely a main network to a distribution network, and realizing the functions of graphic modeling, setting calculation and fault analysis of the distribution network setting calculation system by utilizing a distribution network automation system/a graphic model management system; the generated electronic fixed value list and the calculation book are reported and locally adjusted for auditing, and finally the fixed value list is transmitted to an OMS system for circulation;

and finally, automatically acquiring a power grid model of the distribution network for analysis through a power distribution network relay protection self-adaptive setting calculation platform, and automatically generating a power grid setting model required by an intelligent distribution network setting system, thereby realizing the self-adaptive setting of the distribution network and the management of related data.

According to the technical scheme, the distribution network intelligent setting method based on the self-adaptive setting principle completes data architecture design, deployment architecture design and functional architecture design of a platform according to research on the current setting calculation situation of the existing distribution network, realizes functions of distribution network account modeling, fault calculation, setting calculation, protection device management, calculation book and setting list management, equipment parameter management and the like, realizes self-adaptive setting and automatic check of the relay protection setting value of the distribution network, automatically generates the calculation book and the setting list, solves the problem that the distribution network cannot realize automatic setting calculation of the distribution network due to the reasons of difficult modeling, complex setting and distribution power supply access, reduces the repetitive work of distribution network personnel, realizes automatic dynamic adjustment of the distribution network protection setting value, and lays a technical foundation for intelligent setting of the distribution network.

In general, the distribution network intelligent setting method based on the self-adaptive setting principle of the invention is based on the distribution network rapid modeling technology of the objectification technology, namely the objectification rapid modeling technology for researching ring main units, switching stations and multi-stage series supply models, and automatically generates a distribution network data model by only inputting the incoming and outgoing line quantity, the series supply stage number and the like. And analyzing the data topology connection through a depth-first search algorithm, and automatically generating a power distribution network graph in a standard SVG format for display. The technical problems of complex distribution network modeling and large workload are solved.

Meanwhile, a distribution network intelligent setting calculation technology based on a self-adaptive setting principle establishes setting principle expert libraries of different wiring types, self-adaptive matching of the setting principle under different network structures is realized through topology analysis, and automatic setting of a fixed value is realized on the basis of objective modeling.

Drawings

FIG. 1 is an overall framework diagram of an intelligent distribution network tuning and management system of the present invention;

FIG. 2 is a deployment architecture diagram of the distribution network tuning computation platform of the present invention;

FIG. 3 is a functional architecture diagram of a distribution network tuning computation platform of the present invention;

FIG. 4 is a schematic diagram of a distribution network automation system grid model map file of the present invention;

fig. 5 is a schematic diagram of a distribution network automation power network model data file of the present invention;

FIG. 6 is a schematic diagram of a first-stage switch and a second-stage switch of a 10kV outgoing line;

FIG. 7 is a graph of the operating characteristics of a proportional differential element;

FIG. 8 is a schematic diagram of a ratio differential equation action curve;

FIG. 9 is a logic diagram of interval 1, interval 2 overcurrent I section protection;

FIG. 10 is a logic diagram of protection for the interval 3-8 overcurrent I stage;

FIG. 11 is a zero-sequence overcurrent I-segment protection logic diagram of interval 1 and interval 2;

FIG. 12 is a logic diagram of protection of a zero-sequence overcurrent I section at intervals of 3-8;

FIG. 13 is an adaptive tuning flow diagram of the present invention;

FIG. 14 is a schematic diagram of an adaptive tuning mode of operation file of the present invention;

FIG. 15 is an illustration shown in an open and closed state;

fig. 16 is a branch diagram of the outlet unit.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, 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 some, but not all, embodiments of the present invention.

The distribution network intelligent setting method based on the self-adaptive setting principle is based on an intelligent distribution network setting and management system, and an overall frame diagram of the distribution network intelligent setting method is shown in fig. 1;

the data source of the network distribution model is divided into two stages:

the first stage is as follows: a distribution network automation system (or graph model management system) data model (part) is used. The model of the current distribution network automation system (or graph model management system) is not perfect and cannot meet the working requirement of setting the intelligent distribution network, so in order to simplify the requirement of manual modeling, the power grid data of the distribution network automation system (or graph model management system) is adopted, and meanwhile, the human intervention (human correction) is carried out to ensure the correctness of the data of the distribution network model. Firstly, obtaining the equivalence and fixed value limitation issued by a main network to a distribution network, and then realizing the functions of a distribution network setting calculation system such as graphic modeling, setting calculation and fault analysis; and the generated electronic fixed value list and the calculation book are reported and adjusted for auditing, and finally the fixed value list is transmitted to an OMS system for circulation.

And a second stage: the distribution network model of a distribution network automation system (or a graph model management system) system is completely adopted. And automatically acquiring a power grid model of the distribution network for analysis, and automatically generating the power grid setting model required by the intelligent distribution network setting system. Therefore, the self-adaptive setting of the distribution network and the management of related data are realized.

The following is a detailed description:

deploying the architecture:

the deployment architecture of the distribution network setting calculation platform is distributed, and the distributed deployment architecture shown in fig. 2 means that each county level dispatcher maintains respective basic data on a local dispatcher server, each county level dispatcher maintains respective setting calculation basic data according to a dispatching administration range, and the county level dispatches can realize interaction of the setting calculation data with the local dispatches in a boundary equivalence mode.

And (4) functional architecture:

as shown in fig. 3, the platform functional architecture is divided into a data layer, a base layer, an application layer and a user layer, and the functions of each layer are as follows:

and (3) a data layer: corresponding to the database, is used for storing all data of the platform, including original data, intermediate data, output data and the like.

Base layer: comprises a basic supporting component and a basic application component. The basic support component comprises a power grid model management component, a power grid graph management component, a topology analysis component and the like and is mainly used for managing basic metadata of models, graphs, topologies and the like; the basic application components comprise a simple fault component, a current maximum value component, a branch coefficient component, a principle setting component, a device setting component and the like, the platform computing function is packaged in the form of components, a service interface is provided for an application layer, and the core of the platform is provided.

An application layer: is the concrete embodiment of the platform function requirement, comprising: modeling and setting, data management, system setting and the like.

And (3) a user layer: the user layer is mainly the interaction of the client and the platform.

Modeling based on a distribution network model system:

and a power grid model data interface provided by a distribution network automation system (or a graph model management system) imports a graph file (SVG format) containing a complete connection relation and a model file (XML format) containing equipment parameters and extension connection into the system, and automatically generates a distribution network graph and a calculation model. The distribution network graph is displayed in a uniform and standard SVG format, as shown in FIG. 4, the display effect is consistent with the display of a power grid model in a distribution network automation system, and the distribution network setting calculation personnel can be favorably familiar with the power grid structure. By analyzing the power grid model data file (XML format), as shown in FIG. 5, parameters such as line length, model, transformer model and capacity are obtained, reference parameters are obtained by automatically matching the equipment models according to a distribution network equipment parameter reference library, and impedance parameters of each equipment are automatically calculated.

Data file description:

the extension name of the distribution network model data file is xml, and the extension name comprises an equipment name, a topological connection relation, basic equipment parameters, an equipment dependency relation and the like.

(1) Major data types

The system at least comprises necessary data analyzed by the distribution network setting system shown in the table.

(2) Data representation

The first row of data indicates a unique ID, < cim: XX rdf: ID ═ XXXXXXX' >, and the middle is equipment information, ending with </cim: XX >.

(3) Basic parameters of the equipment

V-AC line

V-shaped transformer

V. others

Graphic file description

The extension name of the distribution network model graphic file is svg, and the data format meets the requirement of the graphic file description specification in the row mark. Including primitives, device angles, sizes, coordinates, etc. And the ID of the device in the graphics svg file should be consistent with that in the data xml file.

Graph batch modeling technology

The batch modeling technology of the distribution network automatically generates a trunk line according to the set number of segments, randomly adds branch lines on the existing line, batch adds cable distribution boxes, power distribution cabinets, ring main units and the like, and adds extension branches in the existing power grid model of the distribution network. The equipment connected with each branch in the cable distribution box, the power distribution cabinet and the ring network cabinet is set once to automatically generate graphs. The distribution network tool box comprises all the devices of the distribution network and supports the random modification of the graphs.

Topology generation and graph generation techniques

And automatically generating a power distribution network graph in a standard SVG format for display by analyzing the data topological connection. The technical problems of complex distribution network modeling and large workload are solved. Graphic element objects contained in the distribution network typical model correspond to database records one by one, one record is automatically added in the database while defining an equipment primitive (line, transformer and bus) object, and attribute parameters and an input interface of the equipment primitive can be modified according to requirements of a user, so that the one-to-one correspondence between the graphics and the database is realized, and the compatibility of the system is ensured.

(1) The following basic primitives can be automatically generated: external equivalent system, two-coil transformer, circuit breaker, circuit, generating line.

(2) And supporting graphical display, wherein the graphic elements in the graph correspond to actual equipment in the power grid, the physical topological relation is analyzed according to the connection relation of parameter input during modeling, and a connection diagram of the outgoing line units is established. The skeleton line set for modeling is shown with a red line.

(3) When the graph is displayed, the length, the impedance, the name of the type number of the segmented line, the CT transformation ratio, the type of the protection device, the protection fixed value of each segment of the stage current and the time fixed value of the stage current can be selectively displayed.

(4) The whole graph picture can be arbitrarily enlarged, reduced and restored, and marks in the graph are synchronously reduced and enlarged during the reduction and the enlargement;

(5) establishing a distribution network tree resource tree according to the hierarchical structure and the regional structure of the power grid, and realizing the navigation and positioning functions of the resource tree; the platform can automatically position the graph by double-clicking the tree nodes in the plant station area, and can also position the tree nodes of the plant station or the outgoing line unit during graph switching.

The following key points describe the intelligent setting calculation of the distribution network based on the self-adaptive setting principle:

firstly, setting principle schemes corresponding to a primary switch and a secondary switch are established according to different wiring modes (public network wiring, private network wiring, hand-pull wiring and the like), the upper-lower level relation of the switches configured and protected is automatically analyzed by analyzing received operation mode files (stored in local), the corresponding setting principle schemes are matched, the self-adaption of the setting principles under different grid structures and operation modes is realized, then, the fixed value calculation is carried out, and the one-key setting of the fixed value of the device is completed.

Establishing a setting principle expert database:

principle tuning

And according to the distribution network protection operation setting principle of the city company, completing the development of a distribution network setting platform principle proprietary library, which is shown in figure 6.

The protection operation setting principle is as follows:

(1) first stage and second stage switch protection

The protection of the 10kV line switch outside the transformer substation is reasonably switched on and off according to a configuration principle, the whole timing can be protected in a graded and layered mode according to the installation position and the superior-inferior relation of the switch, and the switch is divided into a first-stage switch and a second-stage switch. The first-stage switch refers to an off-station switch in protection fit with the substation outgoing switch, and the first-stage switch and the second-stage switch comprise the pole-mounted switch and the looped network cabinet inner-ring outgoing switch.

1) First stage switch protection

Overcurrent I-stage protection

Principle 1: and setting according to 0.9 time of the fixed value of the overcurrent II section of the 10kV outgoing line switch of the transformer substation.

Principle 2: setting according to 0.8 times of the fixed value of the overcurrent I section of the 10kV outgoing line switch of the transformer substation.

Description of the principles: generally, setting is carried out according to the principle 1. For a 10kV line of a 35kV transformer substation, the constant value of the overcurrent II section of the outgoing switch is small (limited to less than 600A) due to the large system equivalent impedance, when the setting is performed according to the principle 1, the protection constant value of the overcurrent I section of the first-stage switch is small, the lower-stage protection coordination is not facilitated, and at the moment, the setting is performed according to the principle 2.

The action time is as follows: 0.1 s; when the adjustment is performed according to the principle 2, 0s is taken.

Overcurrent II stage protection

Principle 1: the setting is carried out according to the setting value which is not more than 0.9 times of the setting value of the overcurrent III section of the 10kV outgoing line switch of the transformer substation.

Principle 2: setting according to the maximum load current of the circuit at the rear section of the evasive switch, wherein the maximum load current is generally 1.3 times of the maximum load current.

Description of the principles: and comprehensively considering the principle 1 and the principle 2 to set.

The action time is as follows: 0.4 s.

Reclosing lock

And when the reclosing input condition is met, the reclosing time is 2.5 s.

2) Second stage switch protection

Overcurrent I-stage protection

Principle 1: the first-stage switch overcurrent I section constant value is set according to 0.8 time.

The action time is as follows: 0 s.

Overcurrent II stage protection

Principle 1: setting according to the fixed value of 0.8 times or less than the overcurrent II section of the first-stage switch.

Description of the principles: and (4) comprehensively considering principle 1 and principle 2 to set values.

The action time is as follows: 0.2 s.

Reclosing lock

And when the reclosing input condition is met, the reclosing time is 2.5 s.

(2) Terminal feeder switch protection

The switching station switch, the ring main unit load outgoing switch and the user demarcation switch are regarded as terminal feeder switches, the two-stage attribution is not brought into, and the protection setting principle is as follows.

1) Switching station switch protection

Overcurrent I-stage protection

Principle 1: and setting 3-6 times of the sum of the distribution transformer rated currents carried by the outgoing line switch.

The action time is as follows: 0 s.

Overcurrent II stage protection

Principle 1: setting according to 1.3-1.5 times of the sum of the distribution transformer rated currents carried by the outgoing line switch.

The action time is as follows: 0.2 s.

2) Ring main unit load outlet switch protection

The ring main unit load outgoing switch is similar to an open-close station outgoing switch, and the protection setting principle is as follows:

overcurrent I-stage protection

Principle 1: setting 3-6 times of the maximum load current carried by the outgoing switch.

The action time is as follows: 0 s.

Overcurrent II stage protection

Principle 1: setting according to 1.3-1.5 times of maximum load current carried by the outgoing line switch.

The action time is as follows: 0.2 s.

(3) User demarcation switch (watchdog) protection

1) Private line subscriber

Overcurrent I-stage protection

Principle 1: and setting according to 0.9 time of the constant value of the overcurrent II section of the 10kV outgoing line switch of the transformer substation.

Principle 2: setting according to 3-6 times of the sum of all distribution transformer rated currents of a user.

Principle 3: setting according to 0.8 times of the fixed value of the overcurrent I section of the 10kV outgoing line switch of the transformer substation.

Description of the principles: generally, the method is adjusted according to the principle 1 and the principle 2. For special line users of a part of 35kV transformer substations, due to the fact that the constant value of the overcurrent II section of the outgoing line switch is small (limited to being smaller than 600A), when values are contradicted according to

principles

1 and 2, the setting can be carried out according to principle 3.

The action time is as follows: 0.1 s; when the setting is made according to rule 3, 0s is taken.

Overcurrent II stage protection

Principle 1: setting according to 1.1-1.2 times of the sum of all distribution transformer rated currents of a user.

The action time is as follows: 0.4 s.

2) T-connected user

Overcurrent I-stage protection

Principle 1: setting according to 3-6 times of the sum of all distribution transformer rated currents of a user.

The action time is as follows: 0 s.

Overcurrent II stage protection

The action time is as follows: 0.2 s.

Setting device

The device setting mainly takes PCS-9721S-NB as a main part, the device is mainly suitable for distribution automation DTU devices in places such as switching stations/switching stations, distribution rooms, ring main units and the like, and each terminal is suitable for the access of electric quantity within 8 intervals. The main functions of the device are shown in Table 4-1

TABLE 4-1 PCS-9721S-NB device function Table

The setting principle of the device is as follows:

(1) bus differential protection

The operation criterion of the ratio differential element is expressed by the formulas 4-1 and 4-2

4-1, 4-2 ratio differential element action criterion; the action characteristic curve is shown in fig. 7.

(3) Line differential protection

The action equation of the ratio differential relay is shown in the formula 4-3, and the action characteristic curve is shown in FIG. 8.

Equation 4-3 for the rate differential relay action;

the action equation of the zero-sequence differential relay is as shown in formula 4-4:

equation of action of formula 4-4 zero sequence differential relay

(4) Overcurrent protection

The device is provided with two sections of timing limit overcurrent protection, and each section has an independent current fixed value, a time fixed value and a control word. The overcurrent I-section protection logic at the interval 1 and the interval 2 is different from the logic at the interval 3-8. The overcurrent I sections of the interval 1 and the interval 2 are in a locked state by default, and are opened only when bus differential protection exits or network topology protection corresponding to the interval exits, while the overcurrent I section protection of the interval 3-8 is not limited by the condition.

The judgment logic of the overcurrent protection is shown in fig. 9 and 10.

(4) Zero sequence overcurrent protection

When the device is used for a small-resistance grounding system and the grounding zero-sequence current is relatively large, the fault can be isolated by using a direct tripping method. Correspondingly, the device provides two-section zero-sequence overcurrent protection, and only alarms but not outputs when the II-section control word is 0. The judgment logic is as shown in FIGS. 11 and 12.

The zero-sequence overcurrent II section protection logic is similar to the zero-sequence overcurrent I section protection logic, but all the spaced zero-sequence overcurrent II sections are directly opened. In combination with the actual situation of the project, the zero-sequence overcurrent protection only needs to alarm but does not exit.

Overcurrent/zero sequence acceleration protection

When a line is commissioned or power is restored, there may be a fault on the line. In such a case, it is generally desirable that the protection device be able to clear the fault in as short a time as possible, rather than over-flow protection for a timed period. The function can be selected to be switched on/off according to requirements.

Reclosing lock

And (5) switching on the circuit at intervals. The weight-off signal has: the system comprises a bus differential protection action, a failure protection action, a non-voltage trip action, a far trip action, a CT disconnection trip, a large-current blocking trip, a hand trip signal and a TWJ abnormal signal. The function can be selected to be switched on/off according to requirements.

(6) Failure protection

The failure protection function of each interval is realized: if the protection element (except the failure protection, the long trip protection and the CT disconnection trip) does not receive the switch trip position after the action trip of the protection element is delayed and the failure protection is set, the switch refuses the trip, other switches on the tripping bus are closed again, and the other switches do not judge the overcurrent.

The function can be selected to be switched on/off according to requirements.

(7) Non-voltage tripping

The circuit interconnection switch is in a self-switching charging state, is in a closing position and a pressure state before being switched into a switch with a non-pressure tripping function, is converted into a non-current and bus-pressure-free state, and is tripped and closed again after time delay, so that the circuit interconnection switch is ensured to act once. The side-to-side switch of the transformer substation and the side-to-side switch of the interconnection switching room on the trunk path can be selectively put into the function. Other switches on the backbone path do not require this function.

(8) High current lockout trip function

When the protection element judges that tripping is needed, if the phase current is larger than the heavy current lockout tripping fixed value, lockout tripping is conducted and memorized, after the transformer substation side outgoing line switch is tripped in a protection mode, no current is detected, tripping is conducted, heavy closing is conducted, and meanwhile the opposite side switch is tripped far away. The function can be selected to be switched on/off according to requirements.

Self-adaptive setting technology

And selecting the established setting scheme or the setting scheme corresponding to the wiring mode according to the actual setting condition, realizing the self-adaptation of the setting principle under different grid structures and operation modes, and completing the one-key setting of the principle level and the device level fixed value. The overall flow of the scheme is shown in figure 13.

Operation mode file parsing technology

(1) Scanning a real-time operation mode file at regular time to obtain a latest file: locally establishing a folder of a power distribution network real-time operation mode, wherein the name of the folder is defined as RunWayInfo, scanning an operation mode file once in five minutes by a program, and automatically acquiring a latest operation mode file according to the name of the operation mode file;

(2) the operation mode file format is as shown in FIG. 14;

(3) according to the content of fig. 14, the switch ID in the file is automatically matched with the switch in the interface according to the outlet unit ID in the file, so as to acquire the open/close state of the switch.

(4) And comparing the switch state in the operation mode file with the switch state in the current library, if the switch state is changed, correcting the state of the switch in the existing outlet unit according to the real-time operation mode file, starting self-adaptive setting, and performing the next analysis operation of the upper and lower switches.

The upper and lower switch analysis techniques:

(1) the selection rule of the zero-level, first-level and second-level switches in the form of the switching station wiring is described by taking fig. 15 as an example;

1) calculating the sum of the capacities of all transformers under the switching station in the outgoing line unit, wherein the calculation formula is as follows:

note that: s_tiRepresenting rated capacity of the transformer, R_iRepresenting the transformer operating rate (output), L_iRepresenting the load importance.

2) Dividing the total volume into three equal parts;

3) searching switching stations with one-third and two-thirds capacities, and if a dividing point is positioned between the two switching stations, selecting the switching station which is close to the power supply;

4) the incoming switch of the outgoing line unit is a zero-level switch; a first-stage switching station at a first boundary point and an incoming switch (closed and protected) of the ring main unit are first-stage switches, and a switch connected with a transformer or a line transformer set (the other side of a line is directly connected with the transformer) is a second-stage switch; the first-stage switching station at the second demarcation point and the incoming line switch (closed and protected) of the ring main unit are second-stage switches;

5) when a multi-stage switching station and a ring main unit exist at the downstream of a first-stage switching station and a ring main unit outgoing line switch between the zero-stage switch and the first-stage switch, a first-stage matching point switch can be selected, and incoming line switches of a lower-stage switching station and the ring main unit are selected as second-stage switches; when a multi-stage switching station and a ring main unit exist at the downstream of a primary switching station and a ring main unit outlet switch between the primary switch and the secondary switch, protection can be put into operation according to a mismatch point setting principle, and the first-stage switch is selected; the other switches (closed, configuration protected) are second stage switches;

(2) the selection rules of the zero-level, first-level, and second-level switches in the branch wiring form are described with reference to fig. 16;

1) calculating the sum of the capacities of the transformers under all branches in the outgoing line unit, wherein the calculation formula is as follows:

2) Dividing the total volume into three equal parts;

3) the main line switches with the capacity of one third and two thirds are searched to be respectively used as a first-stage switch and a second-stage switch, and if a one-third dividing point is positioned between the two switches, the switch close to the power supply is selected to be used as the first-stage switch and the second-stage switch;

4) the switch at the outlet of the branch line between the zero-level switch and the first-level switch is preferably selected as a first-level switch (for example, 2584 pole opening in fig. 16), and the section switch below the branch, the secondary branch outlet switch, and the branch switch directly T-connected to the main line (for example, 2585 pole opening in fig. 16) are preferably selected as second-level switches;

5) the branch switch between the primary switch and the secondary switch is preferably selected as the secondary matching point, such as 2587 posts in fig. 4.

(3) And filling the divided zero-level switch, the first-level switch and the second-level switch into red in the graph, and flashing for visual display of the switches at all levels.

Research on setting principle matching technology

Matching according to the set setting principle scheme of the zero-level switch, the first-level switch and the second-level switch, then performing constant value setting, and displaying the set constant value in an interface;

and finally generating a proposal according to the associated protection device. Showing a zero-level switch, a first-level switch and a second-level switch in the suggested scheme, and showing fixed values of all the switches;

clicking to download, when the CIME file is used for the first time, newly building a CIME file folder locally, and then generating a fixed value single file in a CIME format in the local CIME file folder according to a protection device associated with each switch, wherein the fixed value single file name is as follows: CIME, only a fixed-value single file is generated when clicking again, and a folder does not need to be repeatedly established.

In summary, the invention researches the butt joint with a distribution network automation system (or a graph-model management system), the system provides a power grid model data interface, and the system guides a graph-text piece (SVG format) containing a complete connection relation and a model file (XML format) containing equipment parameters and extension connection into the system to automatically generate a distribution network graph and a calculation model. The method researches the batch modeling technology of the distribution network, automatically generates a trunk line according to the set number of segments, randomly adds branch lines on the existing line, batch adds cable distribution boxes, power distribution cabinets, ring main units and the like, and adds extension branches in the existing power grid model of the distribution network.

Meanwhile, the invention researches the technical principle and the flow of self-adaptive setting, a program can regularly obtain the real-time running mode of the power distribution network, self-adaptive setting is started after the change of the switch position is detected, the topological relation of the switch for protecting the configuration of the outlet unit is analyzed, a primary switch and a secondary switch are determined according to certain load distribution logic, and the setting of a fixed value is output to a setting calculation book and the protection fixed value of each setting branch according to the scheme of the primary switch setting principle and the secondary switch setting principle.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A distribution network intelligent setting method based on a self-adaptive setting principle is based on a distribution network automation system data model and is characterized in that: the method comprises the following steps:

firstly, obtaining the equivalence and the fixed value quota which are issued by a main network to a distribution network, realizing the graphic modeling, the setting calculation and the fault analysis of a distribution network setting calculation system, reporting and debugging a generated electronized fixed value list and a calculation book for auditing, and then transmitting the fixed value list to an OMS system for circulation;

and then automatically acquiring a power grid model of the distribution network for analysis, selecting an established setting scheme or establishing a setting scheme corresponding to a wiring mode according to the actual setting condition, realizing self-adaptation of setting principles under different grid structures and operation modes, and completing one-key setting of a principle level and a device level fixed value.

2. The intelligent setting method for the distribution network according to the self-adaptive setting principle of claim 1, characterized in that: the graphical modeling comprises:

3. The intelligent setting method for the distribution network according to the self-adaptive setting principle of claim 2, characterized in that: the graphical modeling further comprises distribution network batch modeling;

the method comprises the following steps that a trunk line is automatically generated according to a set number of sections, branch lines are added to existing lines at will, cable distribution boxes, power distribution cabinets and ring main units are added in batches, and extension branches are added to an existing power grid model of a distribution network;

the equipment connected with each branch in the cable distribution box, the power distribution cabinet and the ring main unit is set to automatically generate a graph at one time;

4. The intelligent setting method for the distribution network according to the self-adaptive setting principle of claim 3, characterized in that: the graphic modeling further comprises topology generation and graphic generation;

the topology generation and graph generation comprises:

automatically generating a power distribution network graph in a standard SVG format for display by analyzing data topological connection; graphic element objects contained in the distribution network typical model correspond to the records of the database one by one, one record is automatically added into the database while one equipment primitive object is defined, and attribute parameters and an input interface of the equipment primitive can be modified according to the requirements of a user, so that the one-to-one correspondence between the graphics and the database is realized, and the compatibility of the system is ensured.

5. The intelligent setting method for the distribution network according to the self-adaptive setting principle of claim 1, characterized in that: the setting calculation includes the steps of,

firstly, setting principle schemes corresponding to a primary switch and a secondary switch are established according to different wiring modes, the upper-lower stage relation of the switches configured with protection is automatically analyzed by analyzing received operation mode files, the corresponding setting principle schemes are matched, the self-adaption of the setting principles under different grid structures and operation modes is realized, then, the fixed value calculation is carried out, and the one-key setting of the fixed value of the device is completed.

6. The intelligent setting method for the distribution network according to the self-adaptive setting principle of claim 5, characterized in that: the setting principle scheme comprises a switch setting principle, and the switch setting principle comprises the following steps:

1) first stage switch protection

Overcurrent I-section protection:

principle 1: setting according to 0.9 time of the fixed value of the overcurrent II section of the 10kV outgoing line switch of the transformer substation;

principle 2: setting according to 0.8 time of the overcurrent I section fixed value of the 10kV outgoing switch of the transformer substation;

description of the principles: generally, setting according to the principle 1; for a 10kV line of a 35kV transformer substation, the constant value of the overcurrent section II of the outgoing line switch is smaller due to larger system equivalent impedance, when the setting is performed according to the principle 1, the protection constant value of the overcurrent section I of the first-stage switch is smaller, the lower-stage protection coordination is not facilitated, and at the moment, the setting is performed according to the principle 2;

the action time is as follows: 0.1 s; setting according to the principle 2, taking 0 s;

overcurrent II section protection:

principle 1: setting according to a fixed value of 0.9 time which is not more than the overcurrent III section of the 10kV outgoing switch of the transformer substation;

principle 2: setting according to the maximum load current of the circuit at the rear section of the hidden switch, wherein the maximum load current is generally 1.3 times that of the circuit;

description of the principles: comprehensively considering principle 1 and principle 2 and setting;

the action time is as follows: 0.4 s;

reclosing: when the reclosing input condition is met, the reclosing time is taken to be 2.5 s;

2) second stage switch protection

Overcurrent I-section protection:

principle 1: setting according to 0.8 times of the fixed value of the overcurrent I section of the first-stage switch;

the action time is as follows: 0 s;

overcurrent II section protection:

principle 1: setting according to the fixed value of no more than 0.8 times of the overcurrent II section of the first-stage switch;

description of the principles: setting values according to a comprehensive consideration principle 1 and a principle 2;

the action time is as follows: 0.2 s;

(2) terminal feeder switch protection

The switching station switch, the ring main unit load outgoing switch and the user demarcation switch are regarded as terminal feeder switches, and do not bring into the two-stage attribution, and the protection setting principle is as follows:

1) switching station switch protection

Overcurrent I-section protection:

principle 1: setting 3-6 times of the sum of distribution transformer rated currents carried by the outgoing line switch;

the action time is as follows: 0 s;

overcurrent II section protection:

principle 1: setting according to 1.3-1.5 times of the sum of distribution transformer rated currents carried by the outgoing switch;

the action time is as follows: 0.2 s;

2) ring main unit load outlet switch protection

overcurrent I-section protection:

principle 1: setting according to 3-6 times of the maximum load current carried by the outgoing switch;

the action time is as follows: 0 s;

overcurrent II section protection:

principle 1: setting according to 1.3-1.5 times of the maximum load current carried by the outgoing switch;

the action time is as follows: 0.2 s;

(3) user demarcation switch-watch dog protection

1) Private line subscriber

Overcurrent I-stage protection

Principle 1: setting according to 0.9 time of a constant value of an overcurrent II section of a 10kV outgoing switch of the transformer substation;

principle 2: setting according to 3-6 times of the sum of all distribution transformer rated currents of a user;

principle 3: setting according to 0.8 time of the overcurrent I section fixed value of the 10kV outgoing switch of the transformer substation;

description of the principles: setting according to principle 1 and principle 2; for special line users of a part of 35kV transformer substations, because the overcurrent II section constant value of the outgoing line switch is small, when the values are contradictory according to the principle 1 and the principle 2, the setting is carried out according to the principle 3;

the action time is as follows: 0.1 s; when the setting is carried out according to the principle 3, taking 0 s;

overcurrent II section protection:

principle 1: setting according to 1.1-1.2 times of the sum of all distribution transformer rated currents of a user;

the action time is as follows: 0.4 s;

2) t-connected user

Overcurrent I-section protection:

principle 1: setting according to 3-6 times of the sum of all distribution transformer rated currents of a user;

the action time is as follows: 0 s;

overcurrent II section protection:

the action time is as follows: 0.2 s.

7. The intelligent setting method for the distribution network according to the self-adaptive setting principle of claim 5, characterized in that: the setting principle scheme comprises a device setting principle, and the device setting principle comprises the following steps:

(1) bus differential protection

4-1, 4-2 ratio differential element action criterion;

(2) line differential protection

The action equation of the ratio differential relay is as shown in formula 4-3;

equation 4-3 for the rate differential relay action;

equation of action of formula 4-4 zero sequence differential relay

(3) Overcurrent protection

Setting two sections of timing limit overcurrent protection, wherein each section has an independent current fixed value, a time fixed value and a control word;

(4) zero sequence overcurrent protection

When the device is used for a small-resistance grounding system and the grounding zero-sequence current is relatively large, the fault is isolated by a direct tripping method; two-section zero sequence overcurrent protection is provided, and when the II-section control word is 0, only alarm is given and no exit is provided;

(5) reclosing lock

Primary reclosing at intervals of the line; the weight-off signal has: a bus differential protection action, a failure protection action, a no-voltage trip action, a far trip action, a CT disconnection trip, a large-current blocking trip, a hand trip signal and a TWJ abnormal signal; selecting to throw or withdraw according to the requirement;

(6) failure protection

If the protection element does not receive the switch trip position after the failure protection setting delay after other protection actions except failure protection, far trip protection and CT disconnection trip are tripped, the switch is judged to reject tripping, other switches on the tripping bus are closed again, and at the moment, the other switches do not judge overcurrent any more; and selecting to throw or withdraw according to the requirement.

(7) Non-voltage tripping

The circuit interconnection switch is in a self-switching charging state, is in a closed position and a pressure state before being switched into a switch with a non-pressure tripping function, is converted into a non-current and bus-pressure-free state, and is tripped and closed after time delay, so that the circuit interconnection switch is ensured to act once; the transformer substation opposite side switch and the contact switching room opposite side switch on the main path can be selectively put into the function; other switches on the backbone path do not need this function;

(8) high current lockout trip function

When the protection element judges that tripping is needed, if the phase current is larger than the large-current lockout tripping fixed value, lockout tripping is conducted and memorized, after the transformer substation side outgoing line switch is tripped in a protection mode, no current is detected, tripping is conducted and heavy closing is conducted, meanwhile, the opposite side switch is remotely tripped, and switching on/off is selected according to requirements.

8. The intelligent setting method for the distribution network according to the self-adaptive setting principle of claim 1, characterized in that: the method comprises the following steps of selecting an established setting scheme or establishing a setting scheme corresponding to a wiring mode according to an actual setting condition, realizing self-adaptation of setting principles under different grid structures and operation modes, and completing one-key setting of principle level and device level fixed values, and specifically comprises the following steps:

if the change is caused, according to a set rule, a primary switch and a secondary switch are determined according to the switch state and the topological connection of the configuration protection, the setting principle schemes corresponding to the primary switch and the secondary switch are automatically matched, the switch configured with the protection in the outgoing line unit carries out fixed value setting, the set fixed value is displayed in an interface, and finally a suggested scheme is generated according to the associated protection device.

9. The intelligent setting method for distribution networks according to the adaptive setting principle of claim 8, characterized in that: the proposed scheme shows zero-level switches, first-level switches, second-level switches, and the fixed values of the switches.

10. A distribution network intelligent setting system of a self-adaptive setting principle is characterized in that: the system comprises a power distribution network relay protection self-adaptive setting calculation platform, a setting calculation system, a distribution network automation system/graph model management system and an OMS (operation, maintenance and management) system, wherein the setting calculation system, the distribution network automation system/graph model management system and the OMS system are respectively communicated with the power distribution network relay protection self-adaptive setting calculation platform;

the method comprises the following steps that power grid data of a distribution network automation system/a graph model management system are adopted, and manual intervention is carried out to ensure the correctness of distribution network model data; obtaining the equivalence and the fixed value quota issued by a setting calculation system, namely a main network to a distribution network, and realizing the functions of graphic modeling, setting calculation and fault analysis of the distribution network setting calculation system by utilizing a distribution network automation system/a graphic model management system; the generated electronic fixed value list and the calculation book are reported and locally adjusted for auditing, and finally the fixed value list is transmitted to an OMS system for circulation;