Intelligent substation protection operation risk modeling method and device based on distributed Petri network

Abstract

The invention discloses an intelligent substation protection operation risk modeling method and device based on a distributed Petri network. The method comprises the following steps: constructing an incidence matrix of each protected Petri network transition and a place; the related pressing plates are used as libraries to be added to constructed and protected Petri net related transition input libraries; constructing a coupling relation library and a coupling state library of information transmission among the protections; the state of an input library of the protected Petri net is set, all stages of the protected Petri net are deduced and analyzed respectively, according to the coupling relation library, the state value of an output library of the protected Petri net is adopted to update the coupling state library, so that the state value of the related input library of the subsequently protected Petri net is assigned, and the subsequently protected Petri net is started; and if the protection action corresponding to the primary equipment fault is not completed, the protected Petri network is blocked. According to the method, the specific reason for blocking in a certain link during protection operation can be obtained, and the position of a risk point of protection is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of active power distribution network line protection, and in particular to a modeling method and device for intelligent substation protection operation risk based on distributed Petri net. Background Art

[0002] In recent years, with the expansion of power grid, smart substations have been vigorously developed. Due to the addition of merging units and smart terminals in substations, the communication between various protection devices is carried out through the communication network, and soft pressure plates are added to each protection device in smart substations to control the protection behavior, making the work of each protection device more complicated, affecting the reliable operation of the substation.

[0003] In order to better describe the working process of each protection device in the smart substation, Reference 1 builds a visual SCD file management and control system for the system configuration SCD (Substation Configuration Description) file in the smart substation based on the IEC61850 standard. Through the SCD visualization module, we can further understand the transmission of GOOSE information, SV information, etc. between protection devices, merging units and smart terminals in the smart substation.

[0004] Reference 2 relies on the online monitoring and fault diagnosis function of the GOOSE (Generic Object Oriented Substation Event) loop in the smart substation, and takes the GOOSE loop in the line interval and the GOOSE loop in the bus interval as the objects, and studies the Petri net modeling method of the GOOSE loop in the interval. Finally, taking the GOOSE link break in the line interval as an example, the Petri net of the GOOSE loop is used for fault diagnosis, and then the fault point is located. The shortcoming of this document is that it only considers the GOOSE link break as a fault cause, which has limitations.

[0005] Reference 3 establishes an information flow Petri net for line protection. In this information flow Petri net, all devices are placed in a Petri net. This can show the complete process of a line protection device working together with busbar protection, intelligent terminals, and protection and measurement equipment to complete the protection action and trip. However, this document does not describe the abnormal actions of each protection device, such as working after receiving a start failure signal, such as the busbar protection can work normally under busbar faults, and can also work in a certain SV (Sampled Value, sampling value) pressure plate is missed, differential current is generated and malfunction occurs; this document uses a Petri subnet to represent the status values ​​of all soft pressure plates, control words and alarms of the equipment, instead of the status value of the "protection function is put into operation and normal" library in the line Petri net diagram, reflecting the role of these factors in putting the protection function into operation or locking, but the soft / hard pressure plates of the equipment include function pressure plates, SV receiving pressure plates, GOOSE receiving / export pressure plates, and maintenance pressure plates. They play different roles in equipment self-inspection, receiving SV, receiving GOOSE, sending tripping and failure GOOSE messages, etc. Only using the "protection function is put into operation and normal" library cannot reflect the respective roles of these soft / hard pressure plates at different stages.

[0006] The above methods in the prior art have their own shortcomings. They do not consider the role and influence of the pressure plate on the protection work, do not establish Petri nets for each protection separately, and do not consider the coupling relationship between the Petri nets of each protection and the transmission of state information.

[0007] References:

[0008] Reference 1: Liu Hongjun, Gao Xu, Du Liyan, Yu Junjie. Modular design of SCD file management and control system for smart substation[J]. Power System Protection and Control, 2019, 47(3): 154-159.

[0009] Reference 2: Zhou Hongyang, Huang Jiayin, Zhang Chi, Ding Xiaobing, Luo Kun, Zhang Zhiqiang, Wu Fangying, Xu Jiayan. Fault diagnosis of GOOSE circuit in smart substation based on Petri net[J]. China Southern Power Grid Technology, 2017, 11(6): 49-56;

[0010] Reference 3: Chen Jun, Liu Xin, Wang Liping, Zheng Zhong, Ye Xiang, Ren Jie. Research on fault diagnosis and location method of protection control of smart substation based on Petri net [J]. China Testing, 2019, 45(10): 128-134. Summary of the invention

[0011] In view of this, the present invention provides a modeling method and device for protection operation risks of intelligent substations based on distributed Petri nets, which can realize the deduction and analysis of the protection operation behavior of each protection under the action of soft / hard pressure plates, check the completion status of protection actions, analyze and find the specific reasons for the blockage of protection actions at which link.

[0012] The present invention discloses a modeling method for protection operation risk of an intelligent substation based on a distributed Petri net, which comprises:

[0013] According to the working principle of the protection corresponding to each primary equipment in the smart substation, the Petri net technology is used to construct the Petri net of each protection. According to the structure of the Petri net of each protection, the association matrix of the corresponding transition and library is constructed.

[0014] Using the pressure plate configuration of each protection device in the SCD file, add the relevant pressure plate as a library to the input library of the relevant transition of the constructed Petri net of each protection; the relevant pressure plate includes functional pressure plate, SV receiving pressure plate and maintenance pressure plate;

[0015] According to the virtual circuit connection information of the equipment where each protection is located in the SCD file, a coupling relationship library for information transmission between each protection is constructed to describe the coupling relationship between the output library of a protection Petri net and the input library of the related protection Petri net for transmitting messages, and a coupling state library is constructed to store the state information of the double protection of each primary device transmitted to the related protection based on the coupling relationship structure;

[0016] The input place state of the protection Petri net is set, and the protection Petri net is called. Based on the association matrix, each stage of the protection Petri net is deduced and analyzed respectively. According to the coupling relationship library, the state value of the output place of the protection Petri net is used to update the coupling state library, so as to assign the state value of the relevant input place of the subsequent protection Petri net, and start the subsequent protection Petri net; if the protection action corresponding to a device failure is not completed, the protection Petri net is blocked.

[0017] Furthermore, according to the working principle of the protection corresponding to each primary device in the smart substation, the Petri net technology is used to construct the Petri net of each protection, and according to the structure of the Petri net of each protection, the corresponding transition and library association matrix is ​​constructed, including:

[0018] Step 11: For a smart substation, construct corresponding Petri nets for the normal operation and blocking conditions of the line protection on the high voltage side, medium voltage side and low voltage side respectively; for the bus, establish the Petri net of bus protection; establish the Petri net of each circuit breaker protection; establish the Petri net of the normal operation of the main transformer protection and the Petri net of the failure tripping;

[0019] Step 12: According to the Petri net structure of all protections obtained in step 11, construct the corresponding association matrix W of transitions and places, which is used to represent the connection relationship between each transition and each place.

[0020] Further, the step 12 comprises:

[0021] The element corresponding to an input location and the transition it points to in the association matrix is ​​-1; the element corresponding to a transition and an output location in the association matrix is ​​1; if a location has no association with other transitions, the element corresponding to the location and the other transition in the association matrix is ​​0; the elements in the association matrix W are defined as:

[0022]

[0023] Where (t,p) represents the directed arc from transition t to place p, and (p,t) represents the directed arc from place p to transition t.

[0024] When a place is the input place of multiple transitions, the state of the place can only trigger one transition. All subsequent transitions from the place are weighted so that the place can trigger multiple subsequent transitions at the same time in one deduction. The weighted weight is expressed as:

[0025]

[0026] Where Weight(p,t) represents the weight of the directed arc (p,t); when the place is the input place of k transitions, the value of Weight(p,t) is 1 / k.

[0027] Further, the use of the pressure plate configuration of the device where each protection is located in the SCD file, adding the relevant pressure plate as a library place to the input library place of the relevant transition of the Petri net of each protection that has been constructed, includes:

[0028] In the protection Petri net corresponding to each primary device, the merging unit sampling value SV information is uploaded to the protection device; the protection device issues a tripping command and a start-failure signal after receiving the SV information; the tripping command is transmitted to the intelligent terminal, and the start-failure signal is transmitted to the adjacent protection device. In the protection Petri net, the corresponding SV receiving pressure plate is used as a condition for uploading the merging unit information, that is, an input library, to complete the triggering of the first round of transitions; the functional pressure plate and the maintenance pressure plate are used as conditions for the action of the protection device, and together with the upload of the merging unit information, the second round of transitions is triggered; the triggering of the third round of transitions requires that the tripping command, the start-failure information and its corresponding GOOSE send soft pressure plate are in the engaged state.

[0029] Furthermore, the use of the pressure plate configuration of the device where each protection is located in the SCD file, adding the relevant pressure plate as a library place to the input library place of the relevant transition of the Petri net of each protection that has been constructed specifically includes:

[0030] For the Petri net of 500kV line protection, two circuit breakers 5021SV receiving pressure plate, 5022SV receiving pressure plate, and line SV receiving pressure plate are added as input places in the "SV receiving" transition; protection function pressure plate and maintenance pressure plate are added as input places in the "protection function triggering" transition, where the maintenance pressure plate place has an inhibition arc, that is, it can participate in the triggering of the transition only when its state value is 0; in "sending 5021 tripping order to the intelligent terminal", "sending 5022 tripping order to the intelligent terminal", ... the maintenance pressure plate place has an inhibition arc, that is, it can participate in the triggering of the transition only when its state value is 0. On the "end" transition, add 5021 tripping output pressure plate and 5022 tripping output pressure plate as their input locations; on the "send 5021 failure signal output" and "send 5022 failure signal output" transitions, add 5021 failure pressure plate start and 5022 failure pressure plate start as their input locations; in this way, corresponding pressure plates are set in each link of SV reception, protection action, sending tripping signal and starting failure GOOSE signal of the protection to express the different effects of each pressure plate on the 500kV line protection action;

[0031] The addition of each pressure plate in the Petri net of busbar protection, transformer protection, and circuit breaker protection is similar to the addition of pressure plates in the Petri net of 500kV line protection.

[0032] Furthermore, according to the virtual circuit connection information of the equipment where each protection is located in the SCD file, a coupling relationship library for information transmission between each protection is constructed, which is used to describe the coupling relationship between the output library of a protection Petri net and the input library of the related protection Petri net for transmitting messages, and to construct a coupling state library to store the state information of each primary equipment double set of protection transmitted to the related protection based on the coupling relationship structure, including:

[0033] Parse the virtual circuit connection information of each protection device from the SCD file, that is, the tripping GOOSE message sent by a protection device to the intelligent terminal and the start-failure GOOSE message sent to other related protections, and construct a coupling relationship structure to describe the coupling relationship between the output library of a protection Petri net and the input library of the related protection Petri net;

[0034] According to the virtual circuit connection information of each protection output, the corresponding coupling relationship structures are constructed respectively, and then added to the coupling relationship structure array respectively to form a coupling relationship library;

[0035] Construct a coupling state library to store the state information of the double protection of each primary equipment based on the transmission of the coupling relationship structure. The double protection is A set of protection and B set of protection. For each coupling relationship structure, there is a corresponding row in the coupling state library. The first and second columns of the row respectively store the state values ​​of the output locations corresponding to the A set of protection and the B set of protection in the coupling relationship structure.

[0036] Further, the input place state of the protection Petri net is set, the protection Petri net is called, and each stage of the protection Petri net is deduced and analyzed based on the association matrix. According to the coupling relationship library, the state value of the output place of the protection Petri net is used to update the coupling state library, so as to assign the state value of the relevant input place of the subsequent protection Petri net, and start the subsequent protection Petri net; if the protection action corresponding to a device failure is not completed, the protection Petri net is blocked, including:

[0037] Set a primary device to fail, set the throw-in / out status of each pressure plate in the Petri net corresponding to the primary device, update the initial state of the Petri net of the corresponding protection, and deduce the operation of each stage of the Petri net of the protection; after the operation of the Petri net of the protection is completed, obtain the cumulative trigger vector of the transition of the Petri net corresponding to the protection; analyze whether the protection action corresponding to the primary device is completed;

[0038] If the protection action is not completed, the untriggered transitions in the protected Petri net are found by the cumulative trigger vector of the transitions, and each input place of the transition is checked in turn. If the state value of an input place without an inhibition arc is 0, it is determined that the transition is not triggered due to the input place, thereby causing the corresponding protection behavior of the Petri net to fail to complete, that is, the Petri net is blocked; then the coupling relationship library is used to find the subsequent Petri net related to the current Petri net, and the state value of the output place of the current Petri net is assigned to the state value of the relevant input place of the subsequent protection Petri net, and the initial state of the subsequent Petri net is updated so that the subsequent Petri net can be started.

[0039] Furthermore, the Petri net of the protection is called, and each stage of the Petri net of the protection is deduced and analyzed based on the association matrix, including:

[0040] Step 401: Set a primary device to fail, set the start / stop state of each pressure plate in the Petri net corresponding to the primary device, and set the place state vector M of the Petri net corresponding to the primary device;

[0041] Step 402: According to the place state vector M of each transition, determine whether each transition meets the trigger condition, perform behavior deduction of this round on the currently protected Petri net, and calculate the transition trigger vector X of this round;

[0042] Step 403: If there is a non-zero value in the transition trigger vector X, that is, a new transition is triggered, then the association matrix W and the place state vector M of this round are used. j-1 , the transition trigger vector X, and the place state vector M after this round of deduction is calculated j , repeat step 402; when all the transition trigger vectors X are 0, that is, no new transition is triggered, the place state vector M after this round of deduction j is the final state value of the place, and the running deduction of this Petri net ends; j is a positive integer;

[0043] Step 404: After the Petri net operation and deduction of the current protection is completed, the elements of each column of the transition trigger vector X of each round are accumulated respectively to obtain the transition cumulative trigger vector ThitNum of the Petri net; according to the one-dimensional vector ThitNum, check whether the transitions of the tripping command and the start-failure signal required to be issued by the protection are triggered. If all the transitions are triggered, the protection action is completed; otherwise, the protection action is not completed;

[0044] Step 405: using the coupling relationship library, find the subsequent protection Petri nets related to the current protection Petri net, store the state value of the output library of the current Petri net in the coupling state library, and assign it to the state value of the input library related to the subsequent Petri net, so that the subsequent protection Petri nets receive the state value sent by the upper level and are started and deduced;

[0045] Step 406: for other protections in the smart substation, repeat steps 402 to 405 to respectively implement the deduction and analysis of the Petri net of each protection, and pass instructions to the Petri net of the relevant protection.

[0046] Furthermore, the step 401 includes:

[0047] If a pressure plate is put into operation, the state value of the corresponding pressure plate place is set to 1; the Petri net corresponding to the protection of the primary fault device is used as the current protection Petri net; according to the place state vector required by the protection Petri net corresponding to the primary device and the input and output status of a single pressure plate, the place state vector M of the Petri net is set to the initial state vector M0.

[0048] Furthermore, the step 402 includes:

[0049] If the ith transition does not contain an inhibition arc, then the trigger state x of the ith transition is i The calculation is as follows:

[0050]

[0051] Where n is the number of input places of the ith transition; m n is the state value of the nth input place; x i is the i-th element in the transition trigger vector X;

[0052] Only when the state values ​​of all input places without inhibition arcs are greater than 0, can the i-th transition be triggered, and the value of the corresponding i-th element in the transition trigger vector X is 1; otherwise, it is 0, that is, the i-th cannot be triggered;

[0053] If there is a transition with an inhibition arc input place, the i-th transition can be triggered only when the state values ​​of all input places without inhibition arcs are greater than 0 and the state values ​​of all input places with inhibition arcs are less than 0. The trigger state x of the i-th transition is i The calculation is as follows:

[0054]

[0055] In the formula, m 1n is the state value of the nth input place without an inhibition arc, m0k is the state value of the kth input place containing an inhibition arc, k is the number of the input place containing the inhibition arc; x i is the i-th element in the transition trigger vector X;

[0056] When a place is the input place of multiple transitions, assuming that the initial state value of the place is 1, after a transition pointed to by the output of the place is triggered, after the deduction of the transition, the state value of the place becomes 1-1 / k. Since the state value of the place is still greater than 0, other transitions can continue to be triggered.

[0057] The step 403 includes:

[0058] The calculation formula of the state vector of the j-th round library is:

[0059] M j =M j-1 +XW T (6)

[0060] Where M j-1 is the state vector of each place before the jth round of deduction; M j is the state vector of each place after the jth round of deduction; X is the transition trigger vector; W is the association matrix between places and transitions.

[0061] Furthermore, after step 404 and before step 405, the following steps are further included:

[0062] If the protection action is completed, go to step 405 and use the final M to update the coupling state library; if the protection action is not completed, find the abnormal transition and the reason why the abnormal transition is not triggered; find the untriggered transition in the Petri net according to the element value of the transition cumulative trigger vector ThitNum being 0; first judge the transition, if the upper-level transition of the untriggered transition is also not triggered, there is no need to check the input library of the current transition; if a parallel transition of the transition has been triggered, there is no need to check the input library of the current transition;

[0063] For the transitions that are not triggered after screening, check the status values ​​of each input location of the transition in turn. If the status value of an input location without an inhibition arc is 0, it means that the input location is abnormal; if the status value of an input location with an inhibition arc is 1, the input location is judged to be abnormal. The abnormal location at this time is the reason why the protection of the primary device is blocked in the transition, and then the risk location where the protection may occur is discovered, which helps to find the risk point of the protection.

[0064] Furthermore, the structure of the protected Petri net is expressed as:

[0065] N={P,T,F,F0,X,W,M} (1)

[0066] Where P represents a finite set of places, T represents a finite set of transitions, F represents a set of directed arcs between places and transitions, F0 represents an inhibition arc, X represents a transition trigger vector, W represents a weight relationship between places and transitions, and M represents a place state vector in the Petri net.

[0067] The present invention also discloses a modeling device for intelligent substation protection operation risk based on distributed Petri net, which includes:

[0068] The first construction module is used to construct the Petri net of each protection according to the working principle of the protection corresponding to each primary device in the smart substation, and to construct the association matrix of the corresponding transition and library according to the structure of the Petri net of each protection;

[0069] Adding module, used to use the pressure plate configuration of each protection device in the SCD file to add the relevant pressure plate as a library to the input library of the relevant transition of the constructed Petri net of each protection; the relevant pressure plate includes functional pressure plate, SV receiving pressure plate and maintenance pressure plate;

[0070] The second construction module is used to construct a coupling relationship library for information transmission between each protection according to the virtual circuit connection information of the equipment where each protection is located in the SCD file, which is used to describe the coupling relationship of the message transmission between the output library of a protection Petri net and the input library of the related protection Petri net, and to construct a coupling state library to store the state information of the double protection of each primary device transmitted to the related protection based on the coupling relationship structure;

[0071] The blocking module is used to set the input place state of the protection Petri net, call the protection Petri net, deduce and analyze each stage of the protection Petri net based on the association matrix, and update the coupling state library with the state value of the output place of the protection Petri net according to the coupling relationship library, so as to assign the state value of the relevant input place of the subsequent protection Petri net and start the subsequent protection Petri net; if the protection action corresponding to a device failure is not completed, the protection Petri net is blocked.

[0072] Furthermore, according to the working principle of the protection corresponding to each primary device in the smart substation, the Petri net technology is used to construct the Petri net of each protection, and according to the structure of the Petri net of each protection, the corresponding transition and library association matrix is ​​constructed, including:

[0073] The Petri net building module is used to construct the corresponding Petri nets for the normal operation and blocking conditions of the line protection on the high voltage side, medium voltage side and low voltage side of a smart substation; for the busbar, the Petri net for busbar protection is built; the Petri net for each circuit breaker protection is built; the Petri net for the normal operation of the main transformer protection and the Petri net for failure tripping are built;

[0074] The association matrix construction module is used to construct the association matrix W of the corresponding transitions and places according to the structure of all protected Petri nets obtained by the Petri net building module. The association matrix W is used to represent the connection relationship between each transition and each place.

[0075] Furthermore, the association matrix construction module is used to:

[0076] The element corresponding to an input location and the transition it points to in the association matrix is ​​-1; the element corresponding to a transition and an output location in the association matrix is ​​1; if a location has no association with other transitions, the element corresponding to the location and the other transition in the association matrix is ​​0; the elements in the association matrix W are defined as:

[0077]

[0078] Where (t,p) represents the directed arc from transition t to place p, and (p,t) represents the directed arc from place p to transition t.

[0079] When a place is the input place of multiple transitions, the state of the place can only trigger one transition. All subsequent transitions from the place are weighted so that the place can trigger multiple subsequent transitions at the same time in one deduction. The weighted weight is expressed as:

[0080]

[0081] Where Weight(p,t) represents the weight of the directed arc (p,t); when the place is the input place of k transitions, the value of Weight(p,t) is 1 / k.

[0082] Furthermore, the adding module is used for:

[0083] In the protection Petri net corresponding to each primary device, the merging unit sampling value SV information is uploaded to the protection device; the protection device issues a tripping command and a start-failure signal after receiving the SV information; the tripping command is transmitted to the intelligent terminal, and the start-failure signal is transmitted to the adjacent protection device. In the protection Petri net, the corresponding SV receiving pressure plate is used as a condition for uploading the merging unit information, that is, an input library, to complete the triggering of the first round of transitions; the functional pressure plate and the maintenance pressure plate are used as conditions for the action of the protection device, and together with the upload of the merging unit information, the second round of transitions is triggered; the triggering of the third round of transitions requires that the tripping command, the start-failure information and its corresponding GOOSE send soft pressure plate are in the engaged state.

[0084] Furthermore, the adding module is specifically used for:

[0085] For the Petri net of 500kV line protection, two circuit breakers 5021SV receiving pressure plate, 5022SV receiving pressure plate, and line SV receiving pressure plate are added as input places in the "SV receiving" transition; protection function pressure plate and maintenance pressure plate are added as input places in the "protection function triggering" transition, where the maintenance pressure plate place has an inhibition arc, that is, it can participate in the triggering of the transition only when its state value is 0; in "sending 5021 tripping order to the intelligent terminal", "sending 5022 tripping order to the intelligent terminal", ... the maintenance pressure plate place has an inhibition arc, that is, it can participate in the triggering of the transition only when its state value is 0. On the "end" transition, add 5021 tripping output pressure plate and 5022 tripping output pressure plate as their input locations; on the "send 5021 failure signal output" and "send 5022 failure signal output" transitions, add 5021 failure pressure plate start and 5022 failure pressure plate start as their input locations; in this way, corresponding pressure plates are set in each link of SV reception, protection action, sending tripping signal and starting failure GOOSE signal of the protection to express the different effects of each pressure plate on the 500kV line protection action;

[0086] The addition of each pressure plate in the Petri net of busbar protection, transformer protection, and circuit breaker protection is similar to the addition of pressure plates in the Petri net of 500kV line protection.

[0087] Furthermore, the second construction module is used for:

[0088] Parse the virtual circuit connection information of each protection device from the SCD file, that is, the tripping GOOSE message sent by a protection device to the intelligent terminal and the start-failure GOOSE message sent to other related protections, and construct a coupling relationship structure to describe the coupling relationship between the output library of a protection Petri net and the input library of the related protection Petri net;

[0089] According to the virtual circuit connection information of each protection output, the corresponding coupling relationship structures are constructed respectively, and then added to the coupling relationship structure array respectively to form a coupling relationship library;

[0090] Construct a coupling state library to store the state information of the double protection of each primary equipment based on the transmission of the coupling relationship structure. The double protection is A set of protection and B set of protection. For each coupling relationship structure, there is a corresponding row in the coupling state library. The first and second columns of the row respectively store the state values ​​of the output locations corresponding to the A set of protection and the B set of protection in the coupling relationship structure.

[0091] Furthermore, the blocking module is used for:

[0092] Set a primary device to fail, set the throw-in / out status of each pressure plate in the Petri net corresponding to the primary device, update the initial state of the Petri net of the corresponding protection, and deduce the operation of each stage of the Petri net of the protection; after the operation of the Petri net of the protection is completed, obtain the cumulative trigger vector of the transition of the Petri net corresponding to the protection; analyze whether the protection action corresponding to the primary device is completed;

[0093] If the protection action is not completed, the untriggered transitions in the protected Petri net are found by the cumulative trigger vector of the transitions, and each input place of the transition is checked in turn. If the state value of an input place without an inhibition arc is 0, it is determined that the transition is not triggered due to the input place, thereby causing the corresponding protection behavior of the Petri net to fail to complete, that is, the Petri net is blocked; then the coupling relationship library is used to find the subsequent Petri net related to the current Petri net, and the state value of the output place of the current Petri net is assigned to the state value of the relevant input place of the subsequent protection Petri net, and the initial state of the subsequent Petri net is updated so that the subsequent Petri net can be started.

[0094] Furthermore, the blocking occurrence module includes a deduction and analysis unit; the deduction and analysis unit is used to call the Petri net of the protection, and based on the association matrix, deduce and analyze each stage of the Petri net of the protection.

[0095] Furthermore, the deduction and analysis unit includes:

[0096] A setting subunit is used to set a primary device failure, set the throw-in / out state of each pressure plate in the Petri net corresponding to the primary device protection, and set the place state vector M of the Petri net corresponding to the primary device protection;

[0097] The calculation subunit is used to determine whether each transition meets the trigger condition according to the place state vector M of each transition, perform the behavior deduction of this round on the currently protected Petri net, and calculate the transition trigger vector X of this round;

[0098] The deduction subunit is used to use the association matrix W and the current round of library state vector M if there is a non-zero value in the transition trigger vector X, that is, a new transition is triggered j-1 , the transition trigger vector X, and the place state vector M after this round of deduction is calculated j , repeatedly execute the calculation subunit; when the transition trigger vector X is all 0, that is, no new transition is triggered, the state vector M of the library after this round of deduction j is the final state value of the place, and the running deduction of this Petri net ends; j is a positive integer;

[0099] The checking subunit is used to accumulate the elements of each column of the transition trigger vector X of each round after the running deduction of the current protection Petri net is completed, and obtain the transition cumulative trigger vector ThitNum of the Petri net; according to the one-dimensional vector ThitNum, check whether the transitions of the tripping command and the start-failure signal required to be issued by the protection are triggered. If all the transitions are triggered, the protection action is completed; otherwise, the protection action is not completed;

[0100] The assignment subunit is used to use the coupling relationship library to find the subsequent protection Petri nets related to the current protection Petri net, store the state value of the output library of the current Petri net in the coupling state library, and assign it to the state value of the input library related to the subsequent Petri net, so that the subsequent protection Petri nets receive the state value sent by the superior and are started and deduced;

[0101] The iteration subunit is used for other protections in the smart substation. It repeatedly calls the calculation subunit, deduction subunit, inspection subunit and assignment subunit in sequence, so as to realize the deduction and analysis of the Petri net of each protection respectively, and pass instructions to the Petri net of related protection.

[0102] Furthermore, the setting subunit is used for:

[0103] If a pressure plate is put into operation, the state value of the corresponding pressure plate place is set to 1; the Petri net corresponding to the protection of the primary fault device is used as the current protection Petri net; according to the place state vector required by the protection Petri net corresponding to the primary device and the input and output status of a single pressure plate, the place state vector M of the Petri net is set to the initial state vector M0.

[0104] Furthermore, the computing subunit is used for:

[0105] If the ith transition does not contain an inhibition arc, then the trigger state x of the ith transition is i The calculation is as follows:

[0106]

[0107] Where n is the number of input places of the ith transition; m n is the state value of the nth input place; x i is the i-th element in the transition trigger vector X;

[0108] Only when the state values ​​of all input places without inhibition arcs are greater than 0, can the i-th transition be triggered, and the value of the corresponding i-th element in the transition trigger vector X is 1; otherwise, it is 0, that is, the i-th cannot be triggered;

[0109] If there is a transition with an inhibition arc input place, the i-th transition can be triggered only when the state values ​​of all input places without inhibition arcs are greater than 0 and the state values ​​of all input places with inhibition arcs are less than 0. The trigger state x of the i-th transition is i The calculation is as follows:

[0110]

[0111] In the formula, m 1n is the state value of the nth input place without an inhibition arc, m 0k is the state value of the kth input place containing an inhibition arc, k is the number of the input place containing the inhibition arc; x i is the i-th element in the transition trigger vector X;

[0112] When a place is the input place of multiple transitions, assuming that the initial state value of the place is 1, after a transition pointed to by the output of the place is triggered, after the deduction of the transition, the state value of the place becomes 1-1 / k. Since the state value of the place is still greater than 0, other transitions can continue to be triggered.

[0113] The deduction subunit is used for:

[0114] The calculation formula of the state vector of the j-th round library is:

[0115] M j =M j-1 +XW T (6)

[0116] Where M j-1 is the state vector of each place before the jth round of deduction; M j is the state vector of each place after the jth round of deduction; X is the transition trigger vector; W is the association matrix between places and transitions.

[0117] Furthermore, a risk point identification module is provided between the inspection subunit and the assignment subunit, and the risk point identification module is used to:

[0118] If the protection action is completed, go to the assignment subunit and use the final M to update the coupling state library; if the protection action is not completed, find the abnormal transition and the reason why the abnormal transition is not triggered; according to the element value of the transition cumulative trigger vector ThitNum being 0, find the untriggered transition in the Petri net; first judge the transition, if the superior transition of the untriggered transition is also not triggered, there is no need to check the input library of the current transition; if a parallel transition of the transition has been triggered, there is no need to check the input library of the current transition;

[0119] For the transitions that are not triggered after screening, check the status values ​​of each input location of the transition in turn. If the status value of an input location without an inhibition arc is 0, it means that the input location is abnormal; if the status value of an input location with an inhibition arc is 1, the input location is judged to be abnormal. The abnormal location at this time is the reason why the protection of the primary device is blocked in the transition, and then the risk location where the protection may occur is discovered, which helps to find the risk point of the protection.

[0120] Furthermore, the structure of the protected Petri net is expressed as:

[0121] N={P,T,F,F0,X,W,M} (1)

[0122] Where P represents a finite set of places, T represents a finite set of transitions, F represents a set of directed arcs between places and transitions, F0 represents an inhibition arc, X represents a transition trigger vector, W represents a weight relationship between places and transitions, and M represents a place state vector in the Petri net.

[0123] Due to the adoption of the above technical solution, the present invention has the following advantages:

[0124] 1. According to the SCD virtual circuit soft pressure plate information and protection configuration principle, the present invention adds soft / hard pressure plates to each link of the Petri net, and intuitively shows the functions of different soft pressure plates such as SV receiving soft pressure plate, GOOSE export soft pressure plate, various functional soft pressure plates, maintenance hard pressure plates, etc. in each protection action;

[0125] 2. The virtual circuit in the intelligent substation of the present invention transmits GOOSE signals such as tripping and failure between protections. The decentralized Petri net expresses the protection action logic of the primary equipment. In order to transmit the change information of the protection to the adjacent protection, a coupling relationship library and a coupling state library are set up, which store the information transmission relationship between the protections and the specific state information transmitted respectively. The decentralized Petri nets are connected in series through the coupling relationship library, and the subsequent Petri nets are started through the transmitted state information;

[0126] 3. The present invention determines whether the distributed Petri net is fully running according to the cumulative trigger vector of the transition. If it fails to run completely, it is necessary to provide the untriggered transitions and their abnormal locations, so as to find the fault cause of a transition being blocked.

[0127] 4. The present invention proposes a modeling method for the protection operation risk of an intelligent substation based on a distributed Petri net. Taking into account the role of the pressure plate, the protection operation behavior of the intelligent substation can be accurately modeled. The method is applicable to 500kV and 220kV intelligent substations, and can realize the modeling and process analysis of the action behavior of each protection device in the intelligent substation with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0128] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0129] Figure 1 A flow chart of a modeling method for intelligent substation protection operation risk based on distributed Petri nets proposed by the present invention;

[0130] Figure 2 This is the main wiring diagram of the 500kV smart substation mentioned in Example 1 of the present invention;

[0131] Figure 3 This is the Petri net diagram of the normal operation of 500kV line protection. DETAILED DESCRIPTION

[0132] The present invention is further described in conjunction with the accompanying drawings and embodiments, and the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field should fall within the scope of protection of the embodiments of the present invention.

[0133] Since the existing technology does not consider the role and influence of the pressure plate on the protection work, does not establish Petri nets for each protection separately, and does not consider the coupling relationship of each Petri net, it is necessary to establish a separate Petri net for each protection, and add the corresponding library of the pressure plate at each stage of the Petri net. It is necessary to establish the coupling relationship between the relevant output library of each Petri net and the input library of other Petri nets based on the virtual circuit between the protections in SCD, so as to enable the information flow between the Petri nets of each decentralized protection, and realize multiple Petri net calculations for each behavior of each protection action process. For this purpose, see Figure 1 The present invention proposes an embodiment of a modeling method for intelligent substation protection operation risk based on distributed Petri net, which includes:

[0134] According to the working principle of the protection corresponding to each primary equipment in the smart substation, the Petri net technology is used to construct the Petri net of each protection. According to the structure of the Petri net of each protection, the association matrix of the corresponding transition and library is constructed.

[0135] Using the pressure plate configuration of each protection device in the SCD file, add the relevant pressure plate as a library to the input library of the relevant transition of the constructed Petri net of each protection; the relevant pressure plate includes functional pressure plate, SV receiving pressure plate and maintenance pressure plate;

[0136] According to the virtual circuit connection information of the equipment where each protection is located in the SCD file, a coupling relationship library for information transmission between each protection is constructed to describe the coupling relationship between the output library of a protection Petri net and the input library of the related protection Petri net for transmitting messages, and a coupling state library is constructed to store the state information of the double protection of each primary device transmitted to the related protection based on the coupling relationship structure;

[0137] Set a primary device to fail, set the throw-in / out status of each pressure plate in the corresponding protection Petri net of the primary device, that is, set the input place status of the protection Petri net, call the protection Petri net, and deduce and analyze each stage of the protection Petri net based on the association matrix. According to the coupling relationship library, the state value of the output place of the protection Petri net is used to update the coupling state library, so as to assign the state value of the relevant input place of the subsequent protection Petri net, and start the subsequent protection Petri net. If the protection action corresponding to the primary device failure is not completed, the protection Petri net is blocked.

[0138] In one embodiment of the present application, according to the working principle of the protection corresponding to each primary device in the smart substation, the Petri net technology is used to construct the Petri net of each protection, and according to the structure of the Petri net of each protection, the corresponding transition and library association matrix is ​​constructed, including:

[0139] Step 11: For a smart substation, construct corresponding Petri nets for the normal operation and blocking conditions of the line protection on the high voltage side, medium voltage side and low voltage side respectively; for the bus, establish the Petri net of bus protection; establish the Petri net of each circuit breaker protection; establish the Petri net of the normal operation of the main transformer protection and the Petri net of the failure tripping;

[0140] Step 12: According to the structure of all protected Petri nets obtained in step 11, construct the corresponding transition-place association matrix W to represent the connection relationship between each transition and each place.

[0141] In one embodiment of the present application, step 12 includes:

[0142] The element corresponding to an input location and the transition it points to in the association matrix is ​​-1; the element corresponding to a transition and an output location in the association matrix is ​​1; if a location has no association with other transitions, the element corresponding to the location and the other transition in the association matrix is ​​0; the elements in the association matrix W are defined as:

[0143]

[0144] Where (t,p) represents the directed arc from transition t to place p, and (p,t) represents the directed arc from place p to transition t.

[0145] When a place is the input place of multiple transitions, the state of the place can only trigger one transition. All subsequent transitions from the place are weighted so that the place can trigger multiple subsequent transitions at the same time in one deduction. The weighted weight is expressed as:

[0146]

[0147] Where Weight(p,t) represents the weight of the directed arc (p,t); when the place is the input place of k transitions, the value of Weight(p,t) is 1 / k.

[0148] In one embodiment of the present application, using the pressure plate configuration of the device where each protection is located in the SCD file, adding the relevant pressure plate as a library place to the input library place of the relevant transition of the Petri net of each protection that has been constructed, includes:

[0149] In the protection Petri net corresponding to each primary device, the merging unit sampling value SV information is uploaded to the protection device; the protection device issues a tripping command and a start-failure signal after receiving the SV information; the tripping command is transmitted to the intelligent terminal, and the start-failure signal is transmitted to the adjacent protection device. In the protection Petri net, the corresponding SV receiving pressure plate is used as a condition for uploading the merging unit information, that is, an input library, to complete the triggering of the first round of transitions; the functional pressure plate and the maintenance pressure plate are used as conditions for the action of the protection device, and together with the upload of the merging unit information, the second round of transitions is triggered; the triggering of the third round of transitions requires that the tripping command, the start-failure information and its corresponding GOOSE send soft pressure plate are in the engaged state.

[0150] In one embodiment of the present application, the use of the pressure plate configuration of the device where each protection is located in the SCD file, adding the relevant pressure plate as a library place to the input library place of the relevant transition of the Petri net of each protection that has been constructed specifically includes:

[0151] For the Petri net of 500kV line protection, two circuit breakers 5021SV receiving pressure plate, 5022SV receiving pressure plate, and line SV receiving pressure plate are added as input places in the "SV receiving" transition; protection function pressure plate and maintenance pressure plate are added as input places in the "protection function triggering" transition, where the maintenance pressure plate place has an inhibition arc, that is, it can participate in the triggering of the transition only when its state value is 0; in "sending 5021 tripping order to the intelligent terminal", "sending 5022 tripping order to the intelligent terminal", ... the maintenance pressure plate place has an inhibition arc, that is, it can participate in the triggering of the transition only when its state value is 0. On the "end" transition, add 5021 tripping output pressure plate and 5022 tripping output pressure plate as their input locations; on the "send 5021 failure signal output" and "send 5022 failure signal output" transitions, add 5021 failure pressure plate start and 5022 failure pressure plate start as their input locations; in this way, corresponding pressure plates are set in each link of SV reception, protection action, sending tripping signal and starting failure GOOSE signal of the protection to express the different effects of each pressure plate on the 500kV line protection action;

[0152] The addition of each pressure plate in the Petri net of busbar protection, transformer protection, and circuit breaker protection is similar to the addition of pressure plates in the Petri net of 500kV line protection.

[0153] In one embodiment of the present application, according to the virtual circuit connection information of the device where each protection is located in the SCD file, a coupling relationship library for information transmission between each protection is constructed, which is used to describe the coupling relationship of the message transmission between the output library of a protection Petri net and the input library of the related protection Petri net, and construct a coupling state library to store the state information of each primary device double protection transmitted to the related protection based on the coupling relationship structure, including:

[0154] The virtual circuit connection information of each protection device is parsed from the SCD file, that is, the tripping GOOSE message sent by a protection device to the intelligent terminal and the start-failure GOOSE message sent to other related protections, and a coupling relationship structure is constructed to describe the coupling relationship between the output library of a protection Petri net and the input library of the related protection Petri net; wherein, the data structure of the coupling relationship structure can be:

[0155] struct{

[0156] string AC; %Send device number

[0157] string ACtype; %Send device sub-model number

[0158] string ACNUM; % Output location number of the sending device

[0159] string TR; % receiving device number

[0160] string TRtype; % receiving device sub-model number

[0161] string TRNUM; % The number of the input location of the receiving device

[0162] };

[0163] According to the virtual circuit connection information of each protection output, the corresponding coupling relationship structures are constructed respectively, and then added to the coupling relationship structure array respectively to form a coupling relationship library;

[0164] Construct a coupling state library to store the state information of the double protection of each primary equipment based on the transmission of the coupling relationship structure. The double protection is A set of protection and B set of protection. For each coupling relationship structure, there is a corresponding row in the coupling state library. The first and second columns of the row respectively store the state values ​​of the output locations corresponding to the A set of protection and the B set of protection in the coupling relationship structure.

[0165] In one embodiment of the present application, the setting of a primary device failure is to set the throw-in / out state of each pressure plate in the Petri net corresponding to the primary device protection, that is, to set the input place state of the Petri net of the protection, call the Petri net of the protection, and deduce and analyze each stage of the Petri net of the protection based on the association matrix, and update the coupling state library with the state value of the output place of the Petri net of the protection according to the coupling relationship library, so as to assign the state value of the relevant input place of the Petri net of the subsequent protection, and start the Petri net of the subsequent protection; if the protection action corresponding to the primary device failure is not completed, the Petri net of the protection is blocked, including:

[0166] Set a primary device to fail, set the throw-in / out status of each pressure plate in the Petri net corresponding to the primary device, update the initial state of the Petri net of the corresponding protection, and deduce the operation of each stage of the Petri net of the protection; after the operation of the Petri net of the protection is completed, obtain the cumulative trigger vector of the transition of the Petri net corresponding to the protection; analyze whether the protection action corresponding to the primary device is completed;

[0167] If the protection action is not completed, the untriggered transitions in the protected Petri net are found by the cumulative trigger vector of the transitions, and each input place of the transition is checked in turn. If the state value of an input place without an inhibition arc is 0, it is determined that the transition is not triggered due to the input place, thereby causing the corresponding protection behavior of the Petri net to fail to complete, that is, the Petri net is blocked; then the coupling relationship library is used to find the subsequent Petri net related to the current Petri net, and the state value of the output place of the current Petri net is assigned to the state value of the relevant input place of the subsequent protection Petri net, and the initial state of the subsequent Petri net is updated so that the subsequent Petri net can be started.

[0168] In one embodiment of the present application, the Petri net of the protection is called, and each stage of the Petri net of the protection is deduced and analyzed based on the association matrix, including:

[0169] Step 401: Set a primary device to fail, set the start / stop state of each pressure plate in the Petri net corresponding to the primary device, and set the place state vector M of the Petri net corresponding to the primary device;

[0170] Step 402: According to the place state vector M of each transition, determine whether each transition meets the trigger condition, perform behavior deduction of this round on the currently protected Petri net, and calculate the transition trigger vector X of this round;

[0171] Step 403: If there is a non-zero value in the transition trigger vector X, that is, a new transition is triggered, then the association matrix W and the place state vector M of this round are used. j-1 , the transition trigger vector X, and the place state vector M after this round of deduction is calculated j , repeat step 402; when all the transition trigger vectors X are 0, that is, no new transition is triggered, the place state vector M after this round of deduction j is the final state value of the place, and the running deduction of this Petri net ends; j is a positive integer;

[0172] Step 404: After the Petri net operation and deduction of the current protection is completed, the elements of each column of the transition trigger vector X of each round are accumulated respectively to obtain the transition cumulative trigger vector ThitNum of the Petri net; according to the one-dimensional vector ThitNum, check whether the transitions of the tripping command and the start-failure signal required to be issued by the protection are triggered. If all the transitions are triggered, the protection action is completed; otherwise, the protection action is not completed;

[0173] Step 405: using the coupling relationship library, find the subsequent protection Petri nets related to the current protection Petri net, store the state value of the output library of the current Petri net in the coupling state library, and assign it to the state value of the input library related to the subsequent Petri net, so that the subsequent protection Petri nets receive the state value sent by the upper level and are started and deduced;

[0174] Step 406: for other protections in the smart substation, repeat steps 402 to 405 to respectively implement the deduction and analysis of the Petri net of each protection, and pass instructions to the Petri net of the relevant protection.

[0175] In one embodiment of the present application, step 401 includes:

[0176] If a pressure plate is put into operation, the state value of the corresponding pressure plate place is set to 1; the Petri net corresponding to the protection of the primary fault device is used as the current protection Petri net; according to the place state vector required by the protection Petri net corresponding to the primary device and the input and output status of a single pressure plate, the place state vector M of the Petri net is set to the initial state vector M0.

[0177] In one embodiment of the present application, step 402 includes:

[0178] If the ith transition does not contain an inhibition arc, then the trigger state x of the ith transition is i The calculation is as follows:

[0179]

[0180] Where n is the number of input places of the ith transition; m n is the state value of the nth input place; x i is the i-th element in the transition trigger vector X;

[0181] Only when the state values ​​of all input places without inhibition arcs are greater than 0, can the i-th transition be triggered, and the value of the corresponding i-th element in the transition trigger vector X is 1; otherwise, it is 0, that is, the i-th cannot be triggered;

[0182] If there is a transition with an inhibition arc input place, the i-th transition can be triggered only when the state values ​​of all input places without inhibition arcs are greater than 0 and the state values ​​of all input places with inhibition arcs are less than 0. The trigger state x of the i-th transition is i The calculation is as follows:

[0183]

[0184] In the formula, m 1n is the state value of the nth input place without an inhibition arc, m 0k is the state value of the kth input place containing an inhibition arc, k is the number of the input place containing the inhibition arc; x i is the i-th element in the transition trigger vector X;

[0185] When a place is the input place of multiple transitions, assuming that the initial state value of the place is 1, after a transition pointed to by the output of the place is triggered, after the deduction of the transition, the state value of the place becomes 1-1 / k. Since the state value of the place is still greater than 0, other transitions can continue to be triggered.

[0186] The step 403 includes:

[0187] The calculation formula of the state vector of the j-th round library is:

[0188] M j =M j-1 +XW T (6)

[0189] Where M j-1 is the state vector of each place before the jth round of deduction; M j is the state vector of each place after the jth round of deduction; X is the transition trigger vector; W is the association matrix between places and transitions.

[0190] In one embodiment of the present application, after step 404 and before step 405, the following steps are further included:

[0191] If the protection action is completed, go to step 405 and use the final M to update the coupling state library; if the protection action is not completed, find the abnormal transition and the reason why the abnormal transition is not triggered; find the untriggered transition in the Petri net according to the element value of the transition cumulative trigger vector ThitNum being 0; first judge the transition, if the upper-level transition of the untriggered transition is also not triggered, there is no need to check the input library of the current transition; if a parallel transition of the transition has been triggered, there is no need to check the input library of the current transition;

[0192] For the transitions that are not triggered after screening, check the status values ​​of each input location of the transition in turn. If the status value of an input location without an inhibition arc is 0, it means that the input location is abnormal; if the status value of an input location with an inhibition arc is 1, the input location is judged to be abnormal. The abnormal location at this time is the reason why the protection of the primary device is blocked in the transition, and then the risk location where the protection may occur is discovered, which helps to find the risk point of the protection.

[0193] In one embodiment of the present application, the structure of the protected Petri net is expressed as:

[0194] N={P,T,F,F0,X,W,M} (1)

[0195] Where P represents a finite set of places, T represents a finite set of transitions, F represents a set of directed arcs between places and transitions, F0 represents an inhibition arc, X represents a transition trigger vector, W represents a weight relationship between places and transitions, and M represents a place state vector in the Petri net.

[0196] The present invention also provides an embodiment of a modeling device for intelligent substation protection operation risk based on distributed Petri net, which includes:

[0197] The first construction module is used to construct the Petri net of each protection according to the working principle of the protection corresponding to each primary device in the smart substation, and to construct the association matrix of the corresponding transition and library according to the structure of the Petri net of each protection;

[0198] Adding module, used to use the pressure plate configuration of each protection device in the SCD file to add the relevant pressure plate as a library to the input library of the relevant transition of the constructed Petri net of each protection; the relevant pressure plate includes functional pressure plate, SV receiving pressure plate and maintenance pressure plate;

[0199] The second construction module is used to construct a coupling relationship library for information transmission between each protection according to the virtual circuit connection information of the equipment where each protection is located in the SCD file, which is used to describe the coupling relationship of the message transmission between the output library of a protection Petri net and the input library of the related protection Petri net, and to construct a coupling state library to store the state information of the double protection of each primary device transmitted to the related protection based on the coupling relationship structure;

[0200] The blocking module is used to set a primary device failure, set the throw-in and throw-out states of each pressure plate in the Petri net corresponding to the primary device, that is, set the input place state of the Petri net of the protection, call the Petri net of the protection, and deduce and analyze each stage of the Petri net of the protection based on the association matrix. According to the coupling relationship library, the state value of the output place of the Petri net of the protection is used to update the coupling state library, so as to assign the state value of the relevant input place of the Petri net of the subsequent protection, and start the Petri net of the subsequent protection; if the protection action corresponding to the primary device failure is not completed, the Petri net of the protection is blocked.

[0201] In one embodiment of the present application, according to the working principle of the protection corresponding to each primary device in the smart substation, the Petri net technology is used to construct the Petri net of each protection, and according to the structure of the Petri net of each protection, the corresponding transition and library association matrix is ​​constructed, including:

[0202] The Petri net building module is used to construct the corresponding Petri nets for the normal operation and blocking conditions of the line protection on the high voltage side, medium voltage side and low voltage side of a smart substation; for the busbar, the Petri net for busbar protection is built; the Petri net for each circuit breaker protection is built; the Petri net for the normal operation of the main transformer protection and the Petri net for failure tripping are built;

[0203] The association matrix construction module is used to construct the association matrix W of the corresponding transitions and places according to the structure of all protected Petri nets obtained by the Petri net building module. The association matrix W is used to represent the connection relationship between each transition and each place.

[0204] In one embodiment of the present application, the association matrix construction module is used to:

[0205] The element corresponding to an input location and the transition it points to in the association matrix is ​​-1; the element corresponding to a transition and an output location in the association matrix is ​​1; if a location has no association with other transitions, the element corresponding to the location and the other transition in the association matrix is ​​0; the elements in the association matrix W are defined as:

[0206]

[0207] Where (t,p) represents the directed arc from transition t to place p, and (p,t) represents the directed arc from place p to transition t.

[0208] When a place is the input place of multiple transitions, the state of the place can only trigger one transition. All subsequent transitions from the place are weighted so that the place can trigger multiple subsequent transitions at the same time in one deduction. The weighted weight is expressed as:

[0209]

[0210] Where Weight(p,t) represents the weight of the directed arc (p,t); when the place is the input place of k transitions, the value of Weight(p,t) is 1 / k.

[0211] In one embodiment of the present application, the adding module is used to:

[0212] In the protection Petri net corresponding to each primary device, the merging unit sampling value SV information is uploaded to the protection device; the protection device issues a tripping command and a start-failure signal after receiving the SV information; the tripping command is transmitted to the intelligent terminal, and the start-failure signal is transmitted to the adjacent protection device. In the protection Petri net, the corresponding SV receiving pressure plate is used as a condition for uploading the merging unit information, that is, an input library, to complete the triggering of the first round of transitions; the functional pressure plate and the maintenance pressure plate are used as conditions for the action of the protection device, and together with the upload of the merging unit information, the second round of transitions is triggered; the triggering of the third round of transitions requires that the tripping command, the start-failure information and its corresponding GOOSE send soft pressure plate are in the engaged state.

[0213] In one embodiment of the present application, the adding module is specifically used for:

[0214] For the Petri net of 500kV line protection, two circuit breakers 5021SV receiving pressure plate, 5022SV receiving pressure plate, and line SV receiving pressure plate are added as input places in the "SV receiving" transition; protection function pressure plate and maintenance pressure plate are added as input places in the "protection function triggering" transition, where the maintenance pressure plate place has an inhibition arc, that is, it can participate in the triggering of the transition only when its state value is 0; in "sending 5021 tripping order to the intelligent terminal", "sending 5022 tripping order to the intelligent terminal", ... the maintenance pressure plate place has an inhibition arc, that is, it can participate in the triggering of the transition only when its state value is 0. On the "end" transition, add 5021 tripping output pressure plate and 5022 tripping output pressure plate as their input locations; on the "send 5021 failure signal output" and "send 5022 failure signal output" transitions, add 5021 failure pressure plate start and 5022 failure pressure plate start as their input locations; in this way, corresponding pressure plates are set in each link of SV reception, protection action, sending tripping signal and starting failure GOOSE signal of the protection to express the different effects of each pressure plate on the 500kV line protection action;

[0215] The addition of each pressure plate in the Petri net of busbar protection, transformer protection, and circuit breaker protection is similar to the addition of pressure plates in the Petri net of 500kV line protection.

[0216] In one embodiment of the present application, the second construction module is used to:

[0217] Parse the virtual circuit connection information of each protection device from the SCD file, that is, the tripping GOOSE message sent by a protection device to the intelligent terminal and the start-failure GOOSE message sent to other related protections, and construct a coupling relationship structure to describe the coupling relationship between the output library of a protection Petri net and the input library of the related protection Petri net;

[0218] According to the virtual circuit connection information of each protection output, the corresponding coupling relationship structures are constructed respectively, and then added to the coupling relationship structure array respectively to form a coupling relationship library;

[0219] Construct a coupling state library to store the state information of the double protection of each primary equipment based on the transmission of the coupling relationship structure. The double protection is A set of protection and B set of protection. For each coupling relationship structure, there is a corresponding row in the coupling state library. The first and second columns of the row respectively store the state values ​​of the output locations corresponding to the A set of protection and the B set of protection in the coupling relationship structure.

[0220] In one embodiment of the present application, the blocking module is used to:

[0221] Set a primary device to fail, set the throw-in / out status of each pressure plate in the Petri net corresponding to the primary device, update the initial state of the Petri net of the corresponding protection, and deduce the operation of each stage of the Petri net of the protection; after the operation of the Petri net of the protection is completed, obtain the cumulative trigger vector of the transition of the Petri net corresponding to the protection; analyze whether the protection action corresponding to the primary device is completed;

[0222] If the protection action is not completed, the untriggered transitions in the protected Petri net are found by the cumulative trigger vector of the transitions, and each input place of the transition is checked in turn. If the state value of an input place without an inhibition arc is 0, it is determined that the transition is not triggered due to the input place, thereby causing the corresponding protection behavior of the Petri net to fail to complete, that is, the Petri net is blocked; then the coupling relationship library is used to find the subsequent Petri net related to the current Petri net, and the state value of the output place of the current Petri net is assigned to the state value of the relevant input place of the subsequent protection Petri net, and the initial state of the subsequent Petri net is updated so that the subsequent Petri net can be started.

[0223] In one embodiment of the present application, the blocking occurrence module includes a deduction and analysis unit; the deduction and analysis unit is used to call the Petri net of the protection, and based on the association matrix, deduce and analyze each stage of the Petri net of the protection.

[0224] In one embodiment of the present application, the deduction and analysis unit includes:

[0225] A setting subunit is used to set a primary device failure, set the throw-in / out state of each pressure plate in the Petri net corresponding to the primary device protection, and set the place state vector M of the Petri net corresponding to the primary device protection;

[0226] The calculation subunit is used to determine whether each transition meets the trigger condition according to the place state vector M of each transition, perform the behavior deduction of this round on the currently protected Petri net, and calculate the transition trigger vector X of this round;

[0227] The deduction subunit is used to use the association matrix W and the current round of library state vector M if there is a non-zero value in the transition trigger vector X, that is, a new transition is triggered j-1 , the transition trigger vector X, and the place state vector M after this round of deduction is calculated j , repeatedly execute the calculation subunit; when the transition trigger vector X is all 0, that is, no new transition is triggered, the state vector M of the library after this round of deduction j is the final state value of the place, and the running deduction of this Petri net ends; j is a positive integer;

[0228] The checking subunit is used to accumulate the elements of each column of the transition trigger vector X of each round after the running deduction of the current protection Petri net is completed, and obtain the transition cumulative trigger vector ThitNum of the Petri net; according to the one-dimensional vector ThitNum, check whether the transitions of the tripping command and the start-failure signal required to be issued by the protection are triggered. If all the transitions are triggered, the protection action is completed; otherwise, the protection action is not completed;

[0229] The assignment subunit is used to use the coupling relationship library to find the subsequent protection Petri nets related to the current protection Petri net, store the state value of the output library of the current Petri net in the coupling state library, and assign it to the state value of the input library related to the subsequent Petri net, so that the subsequent protection Petri nets receive the state value sent by the superior and are started and deduced;

[0230] The iteration subunit is used for other protections in the smart substation. It repeatedly calls the calculation subunit, deduction subunit, inspection subunit and assignment subunit in sequence, so as to realize the deduction and analysis of the Petri net of each protection respectively, and pass instructions to the Petri net of related protection.

[0231] In one embodiment of the present application, the setting subunit is used to:

[0232] If a pressure plate is put into operation, the state value of the corresponding pressure plate place is set to 1; the Petri net corresponding to the protection of the primary fault device is used as the current protection Petri net; according to the place state vector required by the protection Petri net corresponding to the primary device and the input and output status of a single pressure plate, the place state vector M of the Petri net is set to the initial state vector M0.

[0233] In one embodiment of the present application, the computing subunit is used for:

[0234] If the ith transition does not contain an inhibition arc, then the trigger state x of the ith transition is i The calculation is as follows:

[0235]

[0236] Where n is the number of input places of the ith transition; m n is the state value of the nth input place; x i is the i-th element in the transition trigger vector X;

[0237] Only when the state values ​​of all input places without inhibition arcs are greater than 0, can the i-th transition be triggered, and the value of the corresponding i-th element in the transition trigger vector X is 1; otherwise, it is 0, that is, the i-th cannot be triggered;

[0238] If there is a transition with an inhibition arc input place, the i-th transition can be triggered only when the state values ​​of all input places without inhibition arcs are greater than 0 and the state values ​​of all input places with inhibition arcs are less than 0. The trigger state x of the i-th transition is i The calculation is as follows:

[0239]

[0240] In the formula, m 1n is the state value of the nth input place without an inhibition arc, m 0k is the state value of the kth input place containing an inhibition arc, k is the number of the input place containing the inhibition arc; x i is the i-th element in the transition trigger vector X;

[0241] When a place is the input place of multiple transitions, assuming that the initial state value of the place is 1, after a transition pointed to by the output of the place is triggered, after the deduction of the transition, the state value of the place becomes 1-1 / k. Since the state value of the place is still greater than 0, other transitions can continue to be triggered.

[0242] The deduction subunit is used for:

[0243] The calculation formula of the state vector of the j-th round library is:

[0244] M j =M j-1 +XW T (6)

[0245] Where M j-1 is the state vector of each place before the jth round of deduction; M j is the state vector of each place after the jth round of deduction; X is the transition trigger vector; W is the association matrix between places and transitions.

[0246] In one embodiment of the present application, a risk point identification module is provided between the inspection subunit and the assignment subunit, and the risk point identification module is used to:

[0247] If the protection action is completed, go to the assignment subunit and use the final M to update the coupling state library; if the protection action is not completed, find the abnormal transition and the reason why the abnormal transition is not triggered; according to the element value of the transition cumulative trigger vector ThitNum being 0, find the untriggered transition in the Petri net; first judge the transition, if the superior transition of the untriggered transition is also not triggered, there is no need to check the input library of the current transition; if a parallel transition of the transition has been triggered, there is no need to check the input library of the current transition;

[0248] For the transitions that are not triggered after screening, check the status values ​​of each input location of the transition in turn. If the status value of an input location without an inhibition arc is 0, it means that the input location is abnormal; if the status value of an input location with an inhibition arc is 1, the input location is judged to be abnormal. The abnormal location at this time is the reason why the protection of the primary device is blocked in the transition, and then the risk location where the protection may occur is discovered, which helps to find the risk point of the protection.

[0249] In one embodiment of the present application, the structure of the protected Petri net is expressed as:

[0250] N={P,T,F,F0,X,W,M} (1)

[0251] Where P represents a finite set of places, T represents a finite set of transitions, F represents a set of directed arcs between places and transitions, F0 represents an inhibition arc, X represents a transition trigger vector, W represents a weight relationship between places and transitions, and M represents a place state vector in the Petri net.

[0252] For ease of understanding, the present invention provides a more specific embodiment:

[0253] Embodiment 1:

[0254] The main wiring of the 500kV substation corresponding to Example 1 is as follows Figure 2 As shown;

[0255] A specific experiment is designed to illustrate the effectiveness of the modeling method for the protection operation risk of the smart substation based on the distributed Petri net proposed in the present invention. The specific contents are as follows:

[0256] Decentralized Petri net for 500kV line protection Figure 3 shown.

[0257] (1) According to the relationship between the Petri net location and transition of the normal operation of 500 kV line protection, the correlation matrix W is constructed as follows:

[0258]

[0259] (2) Obtain the initial state M0 of the corresponding place

[0260] Assuming that the line fails and all the pressure plates are put into and withdrawn correctly, the M0 of the Petri net of the line is as follows:

[0261] M0=(1,1,1,1,1,1,1,1,1,1,0,1,0,0,1,1,0,1,1,0,1,0,1,0,1,1,0,0,0,0,0)

[0262] (3) Based on the input place status of each transition, formulate rules to determine whether each transition is triggered, as follows:

[0263]

[0264]

[0265] Thus, we can get the transition trigger vector X1 of the first round of the Petri net according to the initial state M0 of the place:

[0266] X1=(1,0,0,0,0,0,0,0)

[0267] (4) According to the place state calculation formula (6), the place state M1 after the first round is calculated:

[0268] M1=(0,0,0,0,0,0,0,0,0,1,1,1,0,0,1,1,0,1,1,0,1,0,1,0,1,1,0,0,0,0,0)

[0269] (5) After repeated calculations in steps (3)-(4), the transition trigger vectors X2 and X3 for the second and third rounds are obtained respectively:

[0270] X2=(0,1,0,0,0,0,0,0)

[0271] X3=(0,0,1,1,1,1,0,0)

[0272] The fourth round of reasoning results in:

[0273] X4=(0,0,0,0,0,0,1,1)

[0274] M4=(0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1)

[0275] (6) When the transition trigger vector X5 of the fifth round is calculated using M4, it is an all-zero vector. Then the Petri net runs to the fourth round and M4 is obtained as the final state of each place. The cumulative transition trigger vector at this time is:

[0276] ThitNum=(1,1,1,1,1,1,1,1)

[0277] It can be concluded that this Petri net deduction was carried out for 4 rounds, and there was no untriggered transition. In the place state M4, M4(30)=1, M4(31)=1, indicating that both circuit breakers in the line were tripped; M4(28)=1, M4(29)=1, indicating that the protection failure signals were transmitted to the relevant protections, and the protection function was executed;

[0278] (7) According to the coupling relationship library P, the two structures of the line protection transmitting the tripping and starting failure signals to the adjacent circuit breaker protection are as follows:

[0279] P1=struct('AC','PL5021','ACNUM',28,'TR','PB5021','TRNUM',1,'ACtype','L','TRtype','S');

[0280] P1 means transferring the final state value of the place numbered 28 in the PL5021 line protection normal operation Petri net (protection model type is L) to the place state numbered 1 in the PB5021 circuit breaker protection normal operation Petri net (protection model type is S);

[0281] P2=struct('AC','PL5021','ACNUM',29,'TR','PB5022','TRNUM',1,'ACtype','L','TRtype','S');

[0282] P2 means transferring the final state value of the place numbered 29 in the PL5021 line protection normal operation Petri net (protection model type is L) to the place state numbered 1 in the 5022 circuit breaker protection normal operation Petri net (protection model type is S);

[0283] P5=struct('AC','PL5021','ACNUM',30,'TR','PB5021','TRNUM',5,'ACtype','L','TRtype','S');

[0284] P5 means transferring the final state value of the place numbered 30 in the PL5021 line protection normal operation Petri net (protection model type is L) to the place numbered 5 in the PB5021 circuit breaker protection normal operation Petri net (protection model type is S);

[0285] P6=struct('AC','PL5021','ACNUM',31,'TR','PB5022','TRNUM',5,'ACtype','L','TRtype','S');

[0286] P6 means transferring the final state value of the place numbered 31 in the PL5021 line protection normal operation Petri net (protection model type is L) to the place numbered 5 in the PB5022 circuit breaker protection normal operation Petri net (protection model type is S);

[0287] According to the above coupling relationship library P and the state value of the relevant output library in the Petri net operation result, the coupling state library PN is updated as follows:

[0288]

[0289] In PN, PN(1,1), PN(2,1), PN(5,1), and PN(6,1) are 1, indicating that after the line A protection is actuated, the start failure signal and tripping information are transmitted to the corresponding storage locations of the two adjacent circuit breaker A protections through the GOOSE link.

[0290] Embodiment 2:

[0291] On the basis of Example 1, if the 5021GOOSE outlet soft pressure plate in the line protection fails to be applied, the states of the other places are normal. At this time, the initial state value of each place in the Petri net is:

[0292] M0=(1,1,1,1,1,1,1,1,1,1,0,1,0,0,0,1,0,1,1,0,1,0,1,0,1,1,0,0,0,0,0)

[0293] According to the steps of deducing the Petri net in Example 1, the transition trigger vector X of each round can be obtained: i and the place status M i for:

[0294] Round 1:

[0295] X1=(1,0,0,0,0,0,0,0)

[0296] M1=(0,0,0,0,0,0,0,0,0,1,1,1,0,0,0,1,0,1,1,0,1,0,1,0,1,1,0,0,0,0,0)

[0297] Round 2:

[0298] X2=(0,1,0,0,0,0,0,0)

[0299] M2=(0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,1,1,1,1,1,1,1,0,1,1,0,0,0,0,0)

[0300] Round 3:

[0301] X3=(0,0,0,1,1,1,0,0)

[0302] M3=(0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,0,0,0,0,0,0,0,0,1,1,1,1,1,0,0)

[0303] Round 4:

[0304] X4=(0,0,0,0,0,0,0,1)

[0305] M4=(0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,1,0,0,0,0,0,0,0,0,1,0,0,1,1,0,1)

[0306] The Petri net is deduced to the fourth round and the cumulative trigger vector of the transition is:

[0307] ThitNum=(1,1,0,1,1,1,0,1)

[0308] Since ThitNum(3)=0, ThitNum(7)=0, and ThitNum(3) is the superior transition of ThitNum(7), when the superior transition 3 of transition 7 is also not triggered, there is no need to determine the abnormal cause of transition 7, so it is only necessary to determine the cause of the failure to trigger transition 3; check the status of each input library of transition 3, and find that the status value of input library numbered 15 is 0, that is, M0(15)=0 (5021GOOSE outlet pressure plate is not put into operation), that is, transition 3 is not triggered because the 5021GOOSE outlet pressure plate is not put into operation, which in turn causes the protection operation to be incomplete.

[0309] In the final round M4, M4(30)=0, M4(31)=1, the line protection 5021 circuit breaker did not trip, and the 5022 circuit breaker tripped; M4(28)=1, M4(29)=1, indicating that the protection failure signals were all transmitted, and the line protection did not operate completely. The abnormal transition is transition 3, and the reason why it was not triggered is that the 5021 GOOSE outlet pressure plate was not put into use, that is, it is the reason for the blocking of the Petri net.

[0310] Update the coupling state library PN as follows:

[0311]

[0312] In the formula, PN(1,1), PN(2,1), and PN(6,1) are 1, indicating that after the line A protection is actuated, the start-failure signal and tripping information are transmitted to the 5022 circuit breaker A protection through the GOOSE link, and the start-failure signal is transmitted to the 5021 circuit breaker A protection.

[0313] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A modeling method for protection operation risk of smart substation based on distributed Petri net, characterized in that: include: According to the working principle of the protection corresponding to each primary equipment in the smart substation, the Petri net technology is used to construct the Petri net of each protection. According to the structure of the Petri net of each protection, the association matrix of the corresponding transition and library is constructed. Using the pressure plate configuration of each protection device in the SCD file, add the relevant pressure plate as a library to the input library of the relevant transition of the constructed Petri net of each protection; the relevant pressure plate includes functional pressure plate, SV receiving pressure plate and maintenance pressure plate; According to the virtual circuit connection information of the equipment where each protection is located in the SCD file, a coupling relationship library for information transmission between each protection is constructed to describe the coupling relationship between the output library of a protection Petri net and the input library of the related protection Petri net for transmitting messages, and a coupling state library is constructed to store the state information of the double protection of each primary device transmitted to the related protection based on the coupling relationship structure; The input place state of the protection Petri net is set, and the protection Petri net is called. Based on the association matrix, each stage of the protection Petri net is deduced and analyzed respectively. According to the coupling relationship library, the state value of the output place of the protection Petri net is used to update the coupling state library, so as to assign the state value of the relevant input place of the subsequent protection Petri net, and start the subsequent protection Petri net; if the protection action corresponding to a device failure is not completed, the protection Petri net is blocked.

2. The method according to claim 1, characterized in that According to the working principle of the protection corresponding to each primary device in the smart substation, the Petri net technology is used to construct the Petri net of each protection, and according to the structure of the Petri net of each protection, the corresponding transition and library association matrix is ​​constructed, including: Step 11: For a smart substation, construct the corresponding line protection Petri nets for the line protection on the high voltage side, medium voltage side, and low voltage side respectively; for the bus, establish the bus protection Petri net; establish the Petri nets for each circuit breaker protection; and establish the main transformer protection Petri net; Step 12: According to the structure of all protected Petri nets obtained in step 11, construct the corresponding association matrix W of transitions and places. The association matrix W is used to represent the connection relationship between each transition and each place.

3. The method according to claim 2, characterized in that The step 12 comprises: The element corresponding to an input location and the transition it points to in the association matrix is ​​-1; the element corresponding to a transition and an output location in the association matrix is ​​1; if a location has no association with other transitions, the element corresponding to the location and the other transition in the association matrix is ​​0; the elements in the association matrix W are defined as: Where (t,p) represents the directed arc from transition t to place p, and (p,t) represents the directed arc from place p to transition t. When a place is the input place of multiple transitions, the state of the place can only trigger one transition. All subsequent transitions from the place are weighted so that the place can trigger multiple subsequent transitions at the same time in one deduction. The weighted weight is expressed as: Where Weight(p,t) represents the weight of the directed arc (p,t); when the place is the input place of k transitions, the value of Weight(p,t) is 1 / k.

4. The method according to claim 1, characterized in that: The method of using the pressure plate configuration of the device where each protection is located in the SCD file and adding the relevant pressure plate as a library place to the input library place of the relevant transition of the Petri net of each protection that has been constructed includes: In the protection Petri net corresponding to each primary device, the merging unit sampling value SV information is uploaded to the protection device; the protection device issues a tripping command and a start-failure signal after receiving the SV information; the tripping command is transmitted to the intelligent terminal, and the start-failure signal is transmitted to the adjacent protection device. In the protection Petri net, the corresponding SV receiving pressure plate is used as a condition for uploading the merging unit information, that is, an input library, to complete the triggering of the first round of transitions; the functional pressure plate and the maintenance pressure plate are used as conditions for the action of the protection device, and together with the upload of the merging unit information, the second round of transitions is triggered; the triggering of the third round of transitions requires that the tripping command, the start-failure information and its corresponding GOOSE send soft pressure plate are in the engaged state.

5. The method according to claim 1, characterized in that: The method uses the pressure plate configuration of the device where each protection is located in the SCD file, and adds the relevant pressure plate as a library place to the input library place of the relevant transition of the Petri net of each protection that has been constructed, specifically including: For the Petri net of 500kV line protection, two circuit breakers 5021SV receiving pressure plate, 5022SV receiving pressure plate, and line SV receiving pressure plate are added as input places in the "SV receiving" transition; protection function pressure plate and maintenance pressure plate are added as input places in the "protection function triggering" transition, where the maintenance pressure plate place has an inhibition arc, that is, it can participate in the triggering of the transition only when its state value is 0; in the "send 5021 tripping order to the intelligent terminal" and "send 5022 tripping order to the intelligent terminal", .... In the "5021 failure signal output" and "5022 failure signal output" transitions, add the 5021 failure pressure plate and the 5022 failure pressure plate as their input locations; in the "5021 failure signal output" and "5022 failure signal output" transitions, add the 5021 failure pressure plate and the 5022 failure pressure plate as their input locations; in the SV reception, protection action, trip signal sending, and failure GOOSE signal start links of the protection, set the corresponding pressure plates to express the different effects of each pressure plate on the 500kV line protection action; The addition of each pressure plate in the Petri net of busbar protection, transformer protection, and circuit breaker protection is similar to the addition of pressure plates in the Petri net of 500kV line protection.

6. The method according to claim 1, characterized in that According to the virtual circuit connection information of the equipment where each protection is located in the SCD file, a coupling relationship library for information transmission between each protection is constructed to describe the coupling relationship of the message transmission between the output library of a protection Petri net and the input library of the related protection Petri net, and a coupling state library is constructed to store the state information of the double protection of each primary device transmitted to the related protection based on the coupling relationship structure, including: Parse the virtual circuit connection information of each protection device from the SCD file, that is, the tripping GOOSE message sent by a protection device to the intelligent terminal and the start-failure GOOSE message sent to other related protections, and construct a coupling relationship structure to describe the coupling relationship between the output library of a protection Petri net and the input library of the related protection Petri net; According to the virtual circuit connection information of each protection output, the corresponding coupling relationship structures are constructed respectively, and then added to the coupling relationship structure array respectively to form a coupling relationship library; Construct a coupling state library to store the state information of the double protection of each primary equipment based on the transmission of the coupling relationship structure. The double protection is A protection and B protection. For each coupling relationship structure, there is a corresponding row in the coupling state library. The first and second columns of the row respectively store the state value of the output location corresponding to the A protection in the coupling relationship structure, and the first column of the second column stores the state value of the B protection and the output location corresponding to the B protection in the coupling relationship structure.

7. The method according to claim 1, characterized in that The input place state of the protected Petri net is set, the protected Petri net is called, and each stage of the protected Petri net is deduced and analyzed based on the association matrix, and the coupling state library is updated according to the coupling relationship library using the state value of the output place of the protected Petri net, so as to assign the state value of the relevant input place of the subsequent protected Petri net, and start the subsequent protected Petri net; If the protection action corresponding to a device failure is not completed, the Petri net of the protection is blocked, including: Set a primary device to fail, set the throw-in / out status of each pressure plate in the Petri net corresponding to the primary device, update the initial state of the Petri net of the corresponding protection, and deduce the operation of each stage of the Petri net of the protection; after the operation of the Petri net of the protection is completed, obtain the cumulative trigger vector of the transition of the Petri net corresponding to the protection; analyze whether the protection action corresponding to the primary device is completed; If the protection action is not completed, the untriggered transitions in the Petri net of the protection are found by the cumulative trigger vector of the transitions, and the input places of the transition are checked in turn. If the state value of an input place without an inhibition arc is 0, it is determined that the transition is not triggered due to the input place, which causes the corresponding protection behavior of the Petri net to fail to be completed, that is, the Petri net is blocked; then the coupling relationship library is used to find the subsequent protection Petri net related to the current Petri net, and the state value of the output place of the current Petri net is assigned to the state value of the relevant input place of the subsequent protection Petri net, and the initial state of the subsequent protection Petri net is updated so that the subsequent protection Petri net can be started.

8. The method according to claim 1, characterized in that The Petri net of the protection is called, and each stage of the Petri net of the protection is deduced and analyzed based on the association matrix, including: Step 401: Set a primary device to fail, set the start / stop state of each pressure plate in the Petri net corresponding to the primary device, and set the place state vector M of the Petri net corresponding to the primary device. Step 402: According to the place state vector M of each transition, determine whether each transition meets the trigger condition, perform behavior deduction of this round on the currently protected Petri net, and calculate the transition trigger vector X of this round; Step 403: If there is a non-zero value in the transition trigger vector X, that is, a new transition is triggered, then the association matrix W and the place state vector M of this round are used. j-1 , the transition trigger vector X, and the place state vector M after this round of deduction is calculated j , repeat step 402; when all the transition trigger vectors X are 0, that is, no new transition is triggered, the place state vector M after this round of deduction j is the final state value of the place, and the running deduction of this Petri net ends; j is a positive integer; Step 404: After the Petri net operation and deduction of the current protection is completed, the elements of each column of the transition trigger vector X of each round are accumulated respectively to obtain the transition cumulative trigger vector ThitNum of the Petri net; according to the one-dimensional vector ThitNum, check whether the transitions of the tripping command and the start-failure signal required to be issued by the protection are triggered. If all the transitions are triggered, the protection action is completed; otherwise, the protection action is not completed; Step 405: using the coupling relationship library, find the subsequent protection Petri nets related to the current protection Petri net, store the state value of the output library of the current Petri net in the coupling state library, and assign it to the state value of the input library related to the subsequent Petri net, so that the subsequent protection Petri nets receive the state value sent by the upper level and are started and deduced; Step 406: for other protections in the smart substation, repeat steps 402 to 405 to respectively implement the deduction and analysis of the Petri net of each protection, and pass instructions to the Petri net of the relevant protection.

9. The method according to claim 8, characterized in that The step 401 includes: If a pressure plate is put into operation, the state value of the corresponding pressure plate place is set to 1; the Petri net corresponding to the protection of the primary fault device is used as the Petri net of the current protection; according to the place state required for the normal operation of the protection corresponding to the primary device and the in-and-out state of a single pressure plate, the initial state M0 of each place in the Petri net is set.

10. The method according to claim 8, characterized in that The step 402 includes: If the i-th transition does not contain an inhibition arc, the trigger state x of the i-th transition i The calculation is as follows: Where n is the number of input places of the ith transition; m n is the state value of the nth input place; x i is the i-th element in the transition trigger vector X; Only when the state values ​​of all input places without inhibition arcs are greater than 0, can the i-th transition be triggered, and the value of the corresponding i-th element in the transition trigger vector is 1; otherwise, it is 0, that is, the i-th cannot be triggered; If there is a transition with an inhibition arc input place, the i-th transition can be triggered only when the state values ​​of all input places without inhibition arcs are greater than 0 and the state values ​​of all input places with inhibition arcs are less than 0. The trigger state x of the i-th transition is i The calculation is as follows: In the formula, m 1n is the state value of the nth input place without an inhibition arc, m 0k is the state value of the kth input place containing an inhibition arc, k is the number of the input place containing the inhibition arc; x i is the i-th element in the transition trigger vector X; When a place is the input place of multiple transitions, assuming that the initial state value of the place is 1, after a transition pointed to by the output of the place is triggered, after the deduction of the transition, the state value of the place becomes 1-1 / k. If the state value of this place is still greater than 0, other transitions will continue to be triggered. The step 403 includes: The formula for calculating the status of the place in round j is: M j =M j-1 +XW T (6) Where M j-1 is the state value set of each place before the jth round of deduction; M j is the set of state values ​​of each place after the jth round of deduction; X is the transition trigger vector; W is the association matrix between places and transitions.

11. The method according to claim 8, characterized in that After step 404 and before step 405, the following steps are also included: If the protection action is completed, go to step 405 and use the final library state vector M to update the coupling state library; if the protection action is not completed, find the abnormal transition and the reason why the abnormal transition is not triggered; if the element value in the transition cumulative trigger vector ThitNum is 0, find the untriggered transitions in the Petri net; first judge the transition, if the upper-level transition of the untriggered transition is also not triggered, there is no need to check the input library of the current transition; if a parallel transition of the transition has been triggered, there is no need to check the input library of the current transition; For the transitions that are not triggered after screening, check the status values ​​of each input location of the transition in turn. If the status value of an input location without an inhibition arc is 0, it means that the input location is abnormal; if the status value of an input location with an inhibition arc is 1, the input location is judged to be abnormal. The abnormal location at this time is the reason why the protection of the primary device is blocked in the transition, and then the risk location where the protection may occur is discovered, which helps to find the risk point of the protection.

12. The method according to any one of claims 1 to 11, characterized in that: The structure of the protected Petri net is expressed as: N={P,T,F,F0,X,W,M} (1) Where P represents a finite set of places, T represents a finite set of transitions, F represents a set of directed arcs between places and transitions, F0 represents an inhibition arc, X represents a transition trigger vector, W represents a weight relationship between places and transitions, and M represents a place state vector in the Petri net.

13. A modeling device for intelligent substation protection operation risk based on distributed Petri net, characterized in that: include: The first construction module is used to construct the Petri net of each protection according to the working principle of the protection corresponding to each primary device in the smart substation, and to construct the association matrix of the corresponding transition and library according to the structure of the Petri net of each protection; Adding module, used to use the pressure plate configuration of each protection device in the SCD file to add the relevant pressure plate as a library to the input library of the relevant transition of the constructed Petri net of each protection; the relevant pressure plate includes functional pressure plate, SV receiving pressure plate and maintenance pressure plate; The second construction module is used to construct a coupling relationship library for information transmission between each protection according to the virtual circuit connection information of the equipment where each protection is located in the SCD file, which is used to describe the coupling relationship of the message transmission between the output library of a protection Petri net and the input library of the related protection Petri net, and to construct a coupling state library to store the state information of the double protection of each primary device transmitted to the related protection based on the coupling relationship structure; The blocking module is used to set the input place state of the protection Petri net, call the protection Petri net, deduce and analyze each stage of the protection Petri net based on the association matrix, and update the coupling state library with the state value of the output place of the protection Petri net according to the coupling relationship library, so as to assign the state value of the relevant input place of the subsequent protection Petri net and start the subsequent protection Petri net; if the protection action corresponding to a device failure is not completed, the protection Petri net is blocked.

14. The device according to claim 13, characterized in that According to the working principle of the protection corresponding to each primary device in the smart substation, the Petri net technology is used to construct the Petri net of each protection, and according to the Petri net structure of each protection, the corresponding transition and library association matrix is ​​constructed, including: The Petri net building module is used to construct the corresponding line protection Petri nets for the line protection on the high voltage side, medium voltage side and low voltage side of a smart substation; to build the busbar protection Petri net; to build the Petri net for each circuit breaker protection; and to build the main transformer protection Petri net; The association matrix construction module is used to construct the association matrix W of the corresponding transitions and places according to the structure of all protected Petri nets obtained by the Petri net building module. The association matrix W is used to represent the connection relationship between each transition and each place.

15. The device according to claim 14, characterized in that The association matrix construction module is used for: The element corresponding to an input location and the transition it points to in the association matrix is ​​-1; the element corresponding to a transition and an output location in the association matrix is ​​1; if a location has no association with other transitions, the element corresponding to the location and the other transition in the association matrix is ​​0; the elements in the association matrix W are defined as: Where (t,p) represents the directed arc from transition t to place p, and (p,t) represents the directed arc from place p to transition t. When a place is the input place of multiple transitions, the state of the place can only trigger one transition. All subsequent transitions from the place are weighted so that the place can trigger multiple subsequent transitions at the same time in one deduction. The weighted weight is expressed as: Where Weight(p,t) represents the weight of the directed arc (p,t); when the place is the input place of k transitions, the value of Weight(p,t) is 1 / k.

16. The device according to claim 13, characterized in that The adding module is used for: In the protection Petri net corresponding to each primary device, the merging unit sampling value SV information is uploaded to the protection device; after receiving the SV information, the protection device issues a trip command and a start-failure signal; The tripping command is transmitted to the intelligent terminal, and the start-failure signal is transmitted to the adjacent protection device. In the protection Petri net, the corresponding SV receiving pressure plate is used as a condition for uploading the merging unit information, that is, an input library, to complete the triggering of the first round of transitions; the functional pressure plate and the maintenance pressure plate are used as conditions for the protection device action, and together with the merging unit information upload, the second round of transitions is triggered; the triggering of the third round of transitions requires that the tripping command, the start-failure information and its corresponding GOOSE send soft pressure plate are in the engaged state.

17. The device according to claim 13, characterized in that The adding module is specifically used for: For the Petri net of 500kV line protection, two circuit breakers 5021SV receiving pressure plate, 5022SV receiving pressure plate, and line SV receiving pressure plate are added as input places in the "SV receiving" transition; protection function pressure plate and maintenance pressure plate are added as input places in the "protection function triggering" transition, where the maintenance pressure plate place has an inhibition arc, that is, it can participate in the triggering of the transition only when its state value is 0; in the "send 5021 tripping order to the intelligent terminal" and "send 5022 tripping order to the intelligent terminal", .... In the "5021 failure signal output" and "5022 failure signal output" transitions, add the 5021 failure pressure plate and the 5022 failure pressure plate as their input locations; in the "5021 failure signal output" and "5022 failure signal output" transitions, add the 5021 failure pressure plate and the 5022 failure pressure plate as their input locations; in the SV reception, protection action, trip signal sending, and failure GOOSE signal start links of the protection, set the corresponding pressure plates to express the different effects of each pressure plate on the 500kV line protection action; The addition of each pressure plate in the Petri net of busbar protection, transformer protection, and circuit breaker protection is similar to the addition of pressure plates in the Petri net of 500kV line protection.

18. The device according to claim 13, characterized in that The second construction module is used for: Parse the virtual circuit connection information of each protection device from the SCD file, that is, the tripping GOOSE message sent by a protection device to the intelligent terminal and the start-failure GOOSE message sent to other related protections, and construct a coupling relationship structure to describe the coupling relationship between the output library of a protection Petri net and the input library of the related protection Petri net; According to the virtual circuit connection information of each protection output, the corresponding coupling relationship structures are constructed respectively, and then added to the coupling relationship structure array respectively to form a coupling relationship library; Construct a coupling state library to store the state information of the double protection of each primary equipment based on the coupling relationship structure. The double protection is A protection and B protection. Corresponding to each coupling relationship structure, there is a corresponding row in the coupling state library, and the first column and the second column of the row respectively store the state values ​​of the output locations corresponding to the A set protection and the B set protection in the coupling relationship structure.

19. The device according to claim 13, characterized in that The blocking module is used for: Set a primary device to fail, set the start / stop status of each pressure plate in the Petri net corresponding to the primary device, update the initial state of the Petri net of the corresponding protection, and deduce the operation of each stage of the Petri net of the protection; After the operation of the Petri net of the protection is completed, the cumulative trigger vector of the transition of the Petri net corresponding to the protection is obtained; and the protection action corresponding to the primary device is analyzed to see whether it is completed; If the protection action is not completed, the untriggered transition in the Petri net of the protection is found by the cumulative trigger vector of the transition, and each input library of the transition is checked in turn. If the state value of an input library without an inhibition arc is 0, it is determined that the transition is not triggered due to the input library, which causes the corresponding protection behavior of the Petri net to fail to complete, that is, the Petri net is blocked; Then use the coupling relationship library to find the subsequent Petri net related to the current Petri net, assign the state value of the output library of the current Petri net to the state value of the input library related to the subsequent protected Petri net, and update the initial state of the subsequent Petri net so that the subsequent Petri net can be started.

20. The device according to claim 13, characterized in that The blocking occurrence module includes a deduction and analysis unit; the deduction and analysis unit is used to call the Petri net of the protection, and based on the association matrix, deduce and analyze each stage of the Petri net of the protection.

21. The device according to claim 20, characterized in that The deduction and analysis unit comprises: A setting subunit is used to set a primary device failure, set the throw-in / out state of each pressure plate in the Petri net corresponding to the primary device protection, and set the place state vector M of the Petri net corresponding to the primary device protection; The calculation subunit is used to determine whether each transition meets the trigger condition according to the place state vector M of each transition, perform the behavior deduction of this round on the currently protected Petri net, and calculate the transition trigger vector X of this round; The deduction subunit is used to use the association matrix W and the current round of library state vector M if there is a non-zero value in the transition trigger vector X, that is, a new transition is triggered j-1 , the transition trigger vector X, and the place state vector M after this round of deduction is calculated j , repeatedly execute the calculation subunit; when the transition trigger vector X is all 0, that is, no new transition is triggered, the state vector M of the library after this round of deduction j is the final state value of the place, and the running deduction of this Petri net ends; j is a positive integer; The checking subunit is used to accumulate the elements of each column of the transition trigger vector X of each round after the running deduction of the current protection Petri net is completed, and obtain the transition cumulative trigger vector ThitNum of the Petri net; according to the one-dimensional vector ThitNum, check whether the transitions of the tripping command and the start-failure signal required to be issued by the protection are triggered. If all the transitions are triggered, the protection action is completed; otherwise, the protection action is not completed; The assignment subunit is used to use the coupling relationship library to find the subsequent protection Petri nets related to the current protection Petri net, store the state value of the output library of the current Petri net in the coupling state library, and assign it to the state value of the input library related to the subsequent Petri net, so that the subsequent protection Petri nets receive the state value sent by the superior and are started and deduced; The iteration subunit is used for other protections in the smart substation. It repeatedly calls the calculation subunit, deduction subunit, inspection subunit and assignment subunit in sequence, so as to realize the deduction and analysis of the Petri net of each protection respectively, and pass instructions to the Petri net of related protection.

22. The device according to claim 21, characterized in that The setting subunit is used for: If a pressure plate is put into operation, the state value of the corresponding pressure plate place is set to 1; the Petri net corresponding to the protection of the primary fault device is used as the current protection Petri net; according to the place state vector required by the protection Petri net corresponding to the primary device and the input and output status of a single pressure plate, the place state vector M of the Petri net is set to the initial state vector M0.

23. The device according to claim 21, characterized in that The computing subunit is used for: If the ith transition does not contain an inhibition arc, then the trigger state x of the ith transition is i The calculation is as follows: Where n is the number of input places of the ith transition; m n is the state value of the nth input place; x i is the i-th element in the transition trigger vector X; Only when the state values ​​of all input places without inhibition arcs are greater than 0, can the i-th transition be triggered, and the value of the corresponding i-th element in the transition trigger vector X is 1; otherwise, it is 0, that is, the i-th cannot be triggered; If there is a transition with an inhibition arc input place, the i-th transition can be triggered only when the state values ​​of all input places without inhibition arcs are greater than 0 and the state values ​​of all input places with inhibition arcs are less than 0. The trigger state x of the i-th transition is i The calculation is as follows: In the formula, m 1n is the state value of the nth input place without an inhibition arc, m 0k is the state value of the kth input place containing an inhibition arc, k is the number of the input place containing the inhibition arc; x i is the i-th element in the transition trigger vector X; When a place is the input place of multiple transitions, assuming that the initial state value of the place is 1, after a transition pointed to by the output of the place is triggered, after the deduction of the transition, the state value of the place becomes 1-1 / k. If the state value of the place is still greater than 0, other transitions will continue to be triggered. The deduction subunit is used for: The calculation formula of the state vector of the j-th round library is: M j =M j-1 +XW T (6) Where M j-1 is the state vector of each place before the jth round of deduction; M j is the state vector of each place after the jth round of deduction; X is the transition trigger vector; W is the association matrix between places and transitions.

24. The device according to claim 21, characterized in that A risk point identification module is provided between the inspection subunit and the assignment subunit, and the risk point identification module is used to: If the protection action is completed, go to the assignment subunit and use the final library state vector M to update the coupling state library; if the protection action is not completed, find the abnormal transition and the reason why the abnormal transition is not triggered; if the element value in the transition cumulative trigger vector ThitNum is 0, find the untriggered transition in the Petri net; first judge the transition, if the upper transition of the untriggered transition is also not triggered, there is no need to check the input library of the current transition; if a parallel transition of the transition has been triggered, there is no need to check the input library of the current transition; For the transitions that are not triggered after screening, check the status values ​​of each input location of the transition in turn. If the status value of an input location without an inhibition arc is 0, it means that the input location is abnormal; if the status value of an input location with an inhibition arc is 1, the input location is judged to be abnormal. The abnormal location at this time is the reason why the protection of the primary device is blocked in the transition, and then the risk location where the protection may occur is discovered, which helps to find the risk point of the protection.

25. The device according to any one of claims 13 to 24, characterized in that The structure of the protected Petri net is expressed as: N={P,T,F,F0,X,W,M} (1) Where P represents a finite set of places, T represents a finite set of transitions, F represents a set of directed arcs between places and transitions, F0 represents an inhibition arc, X represents a transition trigger vector, W represents a weight relationship between places and transitions, and M represents a place state vector in the Petri net.

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