CN104319744B - Substation system based on protective intelligent center system - Google Patents

Abstract

The invention discloses a substation system based on a protection intelligent center system. The substation system combines the three networking modes of wireless local area network, wide area communication network and optical fiber communication network, and utilizes their respective advantages to realize efficient communication within each substation, between substations, and between the protection intelligence center and each substation; at the same time, The intelligent protection center system uses optical fiber communication to realize the real-time collection of operation data of each substation in the substation system by its acquisition and processing module, and realizes the analysis and calculation of the collected data through its communication module, fault location identification module and trip decision module, and finally realizes After the station domain protection of the substation is out of maintenance, the protection intelligent center system is used as the backup protection system of the faulty substation to replace the protection function of the faulty substation, which greatly improves the reliability of the hub substation system.

Description

A Substation System Based on Protection Intelligence Center System

technical field

The invention belongs to the technical field of electric power system relay protection, and more specifically relates to a substation system based on a protection intelligent center system.

Background technique

At present, relay protection technology presents two development routes with different forms. One is the deep integration of primary and secondary equipment, developing towards the integration of primary and secondary equipment, and finally forming primary smart equipment; the other is to use the advantages of the basic platform of smart substations to integrate between compartments to form centralized substation domain protection for substations. At present, the smart substation technology has been greatly promoted in the State Grid and the South Grid. Several major protection manufacturers in China, including Nanrui Jibao, Sifang, Xuji, etc., have actual products and projects put into operation, primary and secondary equipment The model of separated, centralized station domain protection is more active in academia and industry.

In terms of the development of the power grid itself, both the resource-intensive western region and the load-intensive eastern region have formed hub substation groups that can directly determine the stability of the regional power grid and even the stability of the large power grid. These hub substation groups also face the problems of reduced protection reliability after the secondary system is highly concentrated and slow recovery of the secondary system after the disaster. That is, if the protection of each station adopts the centralized protection of the station area, the dual configuration is still adopted according to the current regulations. When a single set of protection is out of service due to maintenance or other accidents, all protections in the station will lose their dual protection. This is completely different from the current protection configuration where only a certain interval of protection loses duplication. In this case, the reliability of the substation protection system will be significantly reduced. If the triple configuration is adopted, the complexity of protection will be greatly increased, which puts forward high requirements for operation and maintenance, and the economy is poor. In addition, even if the triple system is adopted, the reliability of protection cannot be significantly improved due to the existence of public links such as DC power supply and secondary circuit. At the same time, rebuilding a catastrophic primary device is relatively simple. However, due to the complex installation and commissioning of the secondary reconstruction of protection and the long construction period, it has become a bottleneck restricting the restoration of power supply. Since the main control room of the substation is generally located on the surface, when a catastrophe occurs, the secondary system will also be destroyed at the same time, and the recovery of the power grid will require the simultaneous reconstruction of the primary and secondary systems. Therefore, the research on the protection of hub substation groups faces new requirements: to deal with the special protection problems of this key area, we should focus on the reasonable strengthening of the protection system in the key area, so as to ensure that in the complex and changeable operating environment of the system, including the catastrophic conditions of the power grid Under the correct response of the protective system.

To sum up, it is necessary to provide a new technology that can effectively guarantee the reliability of the secondary system for the centralized protection system in the station area, especially the hub substation group that has a high impact on the safe and stable operation of the regional power grid.

Contents of the invention

Aiming at the above defects or improvement needs of the prior art, the present invention provides a substation system based on the protection intelligent center system, which realizes the internal, Efficient communication between substations and between the protection intelligence center and each substation. At the same time, the reliability of the hub substation system is greatly improved by using the protection intelligence center system.

In order to achieve the above object, the present invention provides a substation system based on a protection intelligence center system, which is characterized in that it includes a protection intelligence center system and a plurality of substations, and the protection intelligence center system is used to provide backup protection for each substation; A VLAN is established within each substation for information exchange within the substation; the core router of each substation joins the wide area communication network based on EVPL to realize the information exchange between adjacent substations; SDH/PDH optical fiber digital private line network, data communication is carried out in connectionless UDP mode.

Preferably, the protection intelligent center system includes an acquisition processing module, a communication module, a fault location discrimination module and a trip decision module; The voltage, current, SMV, GOOSE, circuit breaker status and main protection action information of each substation, and transmit these information and the fault direction information of each component in each substation calculated by using these information to the communication module, which is also used for The circuit breaker status and main protection action information of each substation are transmitted to the fault position discrimination module, and the circuit breaker status information of each substation is mirrored to the trip decision module; the communication module is connected to the trip decision module , for using the voltage, current, SMV, GOOSE of each substation and the fault direction information of each component in each substation to calculate and obtain suddenness information and transmit it to the tripping decision module; the fault location discrimination module is connected to the The tripping decision-making module is used to perform fault-tolerant analysis by using the circuit breaker status and main protection action information of each substation to determine the fault location, and transmit the fault location judgment result to the tripping decision-making module; the tripping decision-making module is used to use each The circuit breaker status information, suddenness information and fault location discrimination results of the substation are combined with the operation status of each substation to make a trip decision.

Preferably, the suddenness information includes grid electrical quantity, state quantity, switch action and main protection action information when a fault breaks out.

Preferably, the tripping decision-making module does not act when the faulty substation is in operation; and disconnects the fault line circuit breaker when the faulty substation is out of operation.

Preferably, the communication module is also used to share the circuit breaker status and main protection action information of each substation among the substations.

Generally speaking, compared with the prior art, the above technical solutions conceived by the present invention have the following beneficial effects: the present invention establishes a substation system based on the protection intelligent center system, and the substation system combines wireless local area network, wide area communication network and The three networking methods of optical fiber communication network use their respective advantages to realize efficient communication within each substation, between substations, and between the protection intelligent center and each substation; at the same time, the protection intelligent center system uses optical fiber communication to realize its collection and processing The module collects the operation data of each substation in the substation system in real time, and realizes the analysis and calculation of the collected data through its communication module, fault location discrimination module and trip decision module, and finally realizes that after the station domain protection of the substation is out of maintenance, the protection intelligent As the backup protection system of the faulty substation, the central system replaces the protection function of the faulty substation, which greatly improves the reliability of the pivotal substation system.

Description of drawings

1 is a schematic diagram of a communication network structure of a substation system based on a protection intelligent center system according to an embodiment of the present invention;

Fig. 2 is the structural representation of protection intelligence center system;

Fig. 3 is a schematic diagram of an example of the installation position of the protection intelligent center system in the substation system;

Fig. 4 is a flowchart of a method for selecting a hot and cold standby mode of the protection intelligent center system.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

As shown in Fig. 1, the communication networking of the substation system based on the protection intelligent center system in the embodiment of the present invention adopts a combination of wireless local area network, wide area communication network and optical fiber communication network. A virtual local area network (Virtual Local Area Network, VLAN) is established inside each substation for information exchange within the substation. The core router of each substation joins a wide area communication network based on Ethernet Virtual Private Line (EVPL). To realize information exchange between adjacent substations. Wherein, the wide area communication network refers to a network in which a Multi-Service Transfer Platform (Multi-Service Transfer Platform, MSTP) device corresponds to a plurality of Virtual Container Trunks (Virtual Container Trunk, VCTrunk). An optical fiber digital dedicated line network based on Synchronous Digital Hierarchy/Plesiochronous Digital Hierarchy (SDH/PDH) is established between the protection intelligence center system and each substation, and the user datagram (User Datagram Protocol, UDP) for data communication. The protection intelligence center system is used to provide backup protection for each substation.

As shown in Figure 2, the intelligent protection center system includes an acquisition and processing module, a communication module, a fault location identification module, and a trip decision module. A communication module and a fault location discrimination module.

The collection and processing module is used to collect the voltage, current, sampled value (sampled measured value, SMV), object-oriented substation general event (generic object oriented substation event, GOOSE), circuit breaker status and main protection action information of each substation. And the fault direction information of each component in each substation calculated by using these information is transmitted to the communication module; the acquisition and processing module is also used to transmit the circuit breaker status and main protection action information of each substation to the fault location identification module; the acquisition and processing module also It is used to mirror the circuit breaker status information of each substation to the trip decision module.

The communication module is used to use the voltage, current, SMV, GOOSE of each substation and the fault direction information of each component in each substation to calculate sudden information and transmit it to the trip decision module. Among them, the sudden information includes information such as electrical quantity, state quantity, switch action and main protection action of the power grid when the fault breaks out. The communication module is also used to share the circuit breaker status and main protection action information of each substation among the substations.

The fault location identification module is used to conduct fault-tolerant analysis using the circuit breaker status and main protection action information of each substation, to identify the fault location, and transmit the fault location identification result to the tripping decision module.

The trip decision-making module is used to make a trip decision by using the circuit breaker status information, sudden information and fault location discrimination results of each substation, combined with the operation status of each substation. Specifically, when the faulty substation is in operation, the trip decision module does not act; when the faulty substation is out of operation, the trip decision module disconnects the faulty circuit breaker.

The installation location of the above protection intelligence center system in the substation system should meet the following three conditions: (A) close to the geographical center of the substation group and the optical fiber intersection point connecting each substation, so as to facilitate the establishment of optical fiber laying between substations. (B) There are no frequent geological disasters, such as collapses, landslides, debris flows, ground subsidence and ground fissures, so that the intelligent protection center system has sufficient disaster resistance and recovery capabilities. (C) Make full use of the existing transmission line network structure to save resources. When the network structure is special, the intelligent protection center system can also be installed near one of the substations.

As shown in Figure 3, taking the Zhengzhou substation group of Henan Power Grid as an example, Zhengzhou, Songshan, and Guandu are 500kV substations, and the rest of the substations are 220kV substations. wiring diagram. First of all, the protection intelligent center system of the new architecture is used as the centralized backup center of the secondary system of the adjacent hub substation. Zhengzhou, Songshan, and Guandu 500kV substations all need to be connected to gas-fired power stations in the future, and this substation group is the largest load center and power exchange transmission center in Henan Province. The system capacity accounts for more than 20% of the province's total capacity. Occupying an important position, it is necessary to make the site selection of the protection emergency center as close as possible to the geographical neutral point of the substation group, so as to facilitate the laying of optical fibers to contact each station and the communication link between the protection emergency center and each station. Secondly, considering that the main geological disasters in Zhengzhou area include landslides, landslides, debris flows, ground subsidence and ground fissures, in order to maintain the independence and sufficient disaster resistance of the protection emergency center, its location is located in the geological area shown in Figure 2. The relatively flat area is built in an underground bunker with an earthquake resistance level of one (for details, refer to the "Code for Seismic Design of Underground Buildings"). In order for the emergency center to have sufficient disaster resistance and rapid recovery capabilities when a disaster strikes. Finally, make full use of the existing transmission line network structure and build optical fibers on the basis of transmission lines to save resources.

As the backup protection center of the substation group, the protection intelligent center system can work in two modes of cold and hot backup. The cold standby of the protection intelligence center system means that the protection intelligence center system does not perform mirror backup for the station domain protection of any substation, only collects and processes the operation data of all substations once, and can only provide backup protection for one substation at the same time. When the station domain protection of a substation is out of maintenance, the protection intelligent center system automatically replaces the station domain protection function of the substation; the tripping mode of the protection intelligent center system in the cold standby mode can only adopt the form of network trip. The hot backup of the protection intelligence center system means: the protection intelligence center system performs mirror backup for the station domain protection of each substation concerned, collects and processes the operation data of all substations in real time, and can provide backup protection for multiple substations at the same time. When the station domain protection of one or more substations is out of maintenance, the protection intelligence center system automatically replaces the station domain protection function of the faulty substation; the tripping mode of the protection intelligence center system in the hot standby mode can be direct jump or network jump. form.

As shown in Figure 4, the cold and hot standby mode selection method for protecting the intelligent center system includes the following steps:

(1) According to the historical operation data of each substation, calculate the fault probability distribution sample space D ₁ , D ₂ ,..., D _N of each substation, where N is the total number of substations in the substation system. Further include the following steps:

(1-1) Let the sample space D ₁ , D ₂ ,…, D _N of each substation fault probability distribution include the following elements: instrument transformer fault probability a, DC system ground fault probability b, lightning arrester fault probability c, busbar Failure probability d, capacitor failure probability e, circuit breaker failure probability f and substation maintenance status g, these elements and their combinations are added as samples to the failure probability distribution sample space D ₁ , D ₂ ,…,D _N of each substation, where , the fault probability distribution sample space D ₁ , D ₂ ,…, D _N of each substation has the same sample composition and arrangement order.

For example, when the elements in the sample space D ₁ , D ₂ ,...,DN of _each substation’s failure probability distribution include the failure probability a of the instrument transformer, the ground fault probability b of the DC system, and the failure probability c of the arrester, each substation The failure probability distribution sample spaces D ₁ , D ₂ ,..., D _N all include the following samples: a, b, c, ab, ac, bc and abc.

(1-2) Calculate the sample value corresponding to the j-th sample S _j in the sample space D _i (i=1,2,…,N) of the fault probability distribution of the i-th substation by the following formula:

Among them, Y _i is the total number of faults in the historical data of the i-th substation, ∑X _k is the sum of the number of times that each element contained in the j-th sample S _j acts on the substation alone and causes the substation to fail, j=1,2, ..., M, M assigns the total number of samples in the sample space D _i to the failure probability.

(2) The sample space D ₁ , D ₂ ,..., D _N is allocated according to the failure probability of each substation, and the health status evaluation model D′ of the equivalent substation system is calculated.

The sample value P′ _j corresponding to the jth sample in the health status evaluation model D′ of the equivalent substation system is calculated by the following formula:

in, φ represents an empty set, ∩ represents an AND operation, and ∩ represents a multiplication operation.

So far, we have obtained the health status evaluation model D′ of the equivalent substation system after integrating the information of each substation, which comprehensively reflects the overall health status of the substation group.

(3) Sum all the sample values in the health status evaluation model D′ of the equivalent substation system to obtain the health status of the equivalent substation system, which reflects the probability of regional faults occurring in each substation as an equivalent whole size.

(4) According to the health status of the equivalent substation system, combined with the economic loss data corresponding to the regional faults in each substation in history, predict the economic loss caused by the fault of the substation system, and compare the prediction results with the switching of cold and hot standby The cost is compared, and the cold and hot standby selection decision for protecting the intelligent center system is obtained. Specifically, when the former is greater than the latter, the protection intelligence center system adopts the hot standby mode, otherwise, the protection intelligence center system adopts the cold standby mode.

The working principle of the above protection intelligence center system is as follows:

Install the protection intelligence center system at the selected location, and collect the historical operation data of surrounding substations (failure probability of instrument transformer, DC system ground fault probability, lightning arrester failure probability, bus failure probability, capacitor failure probability, circuit breaker failure probability and substation maintenance status), model calculation of the substation system, and make a decision on the selection of cold and hot standby modes for protecting the intelligent center system. After that, the standby mode will not change. Taking the hot standby mode as an example, the intelligent protection center system establishes information connection with the surrounding substations through optical fiber, and collects the voltage, current, SMV, GOOSE, circuit breaker status and main protection action information of each substation in real time through the acquisition and processing module. These information and the fault direction information of each component in each substation calculated by using this information are transmitted to the communication module. The state information of the circuit breaker is mirrored to the trip decision-making module; the communication module uses the voltage, current, SMV and GOOSE of each substation and the fault direction information of each component in each substation to calculate the unexpected information and transmit it to the trip decision-making module. At the same time, the communication module shares the circuit breaker status and main protection action information of each substation among the substations; the fault location identification module uses the circuit breaker status and main protection action information of each substation to perform fault-tolerant analysis to identify the fault location and The results are sent to the trip decision module; the trip decision module makes a trip decision by using the circuit breaker status information, sudden information and fault location discrimination results of each substation, combined with the operation status of each substation.

It is easy for those skilled in the art to understand that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, All should be included within the protection scope of the present invention.

Claims (4)

1. A transformer substation system based on a protection intelligent center system is characterized by comprising the protection intelligent center system and a plurality of transformer substations, wherein the protection intelligent center system is used for providing backup protection for each transformer substation; establishing a VLAN in each transformer substation for information exchange in the transformer substation; a core router of each transformer substation is added into an EVPL-based wide area communication network to realize information exchange of adjacent transformer substations; an SDH/PDH-based optical fiber digital private network is established between the protection intelligent central system and each transformer substation, and data communication is carried out in a connectionless UDP (user Datagram protocol)/PDH (digital subscriber hierarchy) mode; the intelligent protection center system comprises an acquisition processing module, a communication module, a fault position judging module and a tripping decision module;

the acquisition processing module is respectively connected with the communication module, the fault position judging module and the trip decision module, and is used for acquiring voltage, current, SMV, GOOSE, breaker state and main protection action information of each transformer substation, transmitting the information and fault direction information of each element in each transformer substation calculated by using the information to the communication module, transmitting the breaker state and main protection action information of each transformer substation to the fault position judging module, and mirroring the breaker state information of each transformer substation to the trip decision module;

the communication module is connected with the trip decision module and is used for calculating to obtain sudden information and transmitting the sudden information to the trip decision module by utilizing the voltage, the current, the SMV and the GOOSE of each transformer substation and the fault direction information of each element in each transformer substation;

the fault position judging module is connected with the trip decision module and is used for carrying out fault-tolerant analysis by utilizing the breaker state and the main protection action information of each transformer substation, judging the fault position and transmitting the fault position judging result to the trip decision module;

and the trip decision module is used for making a trip decision by utilizing the breaker state information, the emergent information and the fault position judgment result of each transformer substation and combining the commissioning state of each transformer substation.

2. The substation system based on a protection smart center system according to claim 1, wherein the bursty information comprises grid electrical quantities, state quantities, switching actions and primary protection action information at the time of a fault burst.

3. The protection smart center system based substation system of claim 1 or 2, wherein the trip decision module is not active when the failed substation is in commissioning; and opening the fault line breaker when the faulted substation is in the operation quitting state.

4. The substation system based on the protection intelligent center system according to claim 3, wherein the communication module is further configured to share the breaker state and the main protection action information of each substation among the substations.