A power distribution network protection setting value setting method and setting system

Abstract

The embodiment of the present application relates to the technical field of network protection, and discloses a kind of power distribution network protection setting value setting method and setting system, the method comprises: simulation obtains the sampling information delay data under different communication scenarios, to form simulation delay database;Through sampling delay compensation, obtain current delay information;According to the current delay information, determine the current communication scenario from the simulation delay database;Obtain the delay distribution information corresponding to the current communication scenario;According to the delay distribution information, adjust the power distribution network protection setting value corresponding to the current communication scenario. Implement the embodiment of the present application, can adjust the action setting value size of network protection, obtain the effect that protection setting value and sampling synchronization condition are self-adapting.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of distribution network protection, in particular to a setting method and system for setting a distribution network protection setting value. BACKGROUND

[0002] At present, with the continuous development of intelligent distribution network and communication technology, a new generation of distribution network protection can obtain regional open current information, and construct a wide-area and networked differential protection method. However, the differential protection needs to meet strict communication conditions, and the synchronization of sampling information greatly affects the implementation effect of the differential protection. The networked transmission of sampling information faces the multiple selectivity of communication paths, and the concurrent transmission of massive information causes the uncertainty of communication delay, which seriously restricts the implementation of the networked protection method based on regional information through the communication network.

[0003] However, it is found in practice that the existing differential protection determines the protection action by comparing whether the differential current of the same time measured by both ends is greater than a certain threshold (protection setting value). However, due to the existence of communication delay, the current measurement values of both ends have a time difference, which is equivalent to using the current at T1 time and the current at T2 time for differential calculation, which will lead to inaccurate calculation results and cause protection misoperation or refusal. SUMMARY

[0004] The embodiments of the present application disclose a setting method and system for setting a distribution network protection setting value, which can adjust the action setting value of the networked protection, and achieve the adaptive effect of the protection setting value and the sampling synchronization condition.

[0005] The first aspect of the embodiments of the present application discloses a setting method for a distribution network protection setting value, and the method comprises the following steps:

[0006] Simulation is performed to obtain sampling information delay data under different communication scenarios to form a simulation delay database;

[0007] The current delay information is obtained through sampling delay compensation;

[0008] According to the current delay information, the current communication scenario is determined from the simulation delay database;

[0009] The delay distribution information corresponding to the current communication scenario is obtained;

[0010] According to the delay distribution information, the distribution network protection setting value corresponding to the current communication scenario is adjusted.

[0011] As another optional implementation, in the first aspect of the embodiments of the present application, the current communication scenario is determined from the simulation delay database according to the current delay information, which comprises the following steps:

[0012] determining a candidate communication scenario containing the current delay information from the simulation delay database;

[0013] normalizing the sampling information delay data in each candidate communication scenario to obtain first probability data of the current delay information appearing in each candidate communication scenario;

[0014] dividing each first probability data by the sum of the probability data to calculate second probability data of each candidate communication scenario being the current communication scenario;

[0015] selecting a communication scenario with the highest probability value from the second probability data as the current communication scenario.

[0016] As another optional implementation, in the first aspect of the embodiment of the present application, the adjusting the power grid protection setting value corresponding to the current communication scenario according to the delay distribution information comprises:

[0017] obtaining an initial power grid protection setting value of a protection element in the current communication scenario;

[0018] obtaining the sum of currents at both ends of the protection element to determine an ideal differential current value of the protection element;

[0019] determining a communication delay at both ends of the protection element according to the delay distribution information;

[0020] obtaining the sum of currents at both ends of the protection element in the communication delay state to determine an actual differential current value of the protection element;

[0021] subtracting the actual differential current value from the initial differential current value to calculate a delay differential current value of the protection element;

[0022] adding the delay differential current value and the initial power grid protection setting value to obtain an actual protection setting value;

[0023] adjusting the initial power grid protection setting value to the actual protection setting value.

[0024] As another optional implementation, in the first aspect of the embodiment of the present application, after the initial power grid protection setting value is adjusted to the actual protection setting value, the method further comprises:

[0025] detecting whether the actual differential current value is greater than the actual protection setting value; if yes, controlling the protection element to perform a protection action.

[0026] The second aspect of the embodiment of the present application discloses a setting system, which comprises:

[0027] a simulation unit, configured to simulate sampling information delay data in different communication scenarios to form a simulation delay database;

[0028] a first obtaining unit, configured to obtain current delay information by sampling delay compensation;

[0029] a determining unit, configured to determine a current communication scenario from the simulation delay database according to the current delay information;

[0030] a second obtaining unit, configured to obtain delay distribution information corresponding to the current communication scenario;

[0031] an adjusting unit, configured to adjust power grid protection setting value corresponding to the current communication scenario according to the delay distribution information.

[0032] As an optional implementation, in the second aspect of the embodiment of the present application, the determining unit comprises:

[0033] a first determining sub-unit, configured to determine candidate communication scenarios containing the current delay information from the simulation delay database;

[0034] a normal distribution sub-unit, configured to perform normal distribution on the sampling information delay data in each of the candidate communication scenarios to obtain first probability data of occurrence of the current delay information in each of the candidate communication scenarios;

[0035] a first calculating sub-unit, configured to divide each of the first probability data by the sum of the probability data to calculate second probability data of each of the candidate communication scenarios being the current communication scenario;

[0036] a selecting sub-unit, configured to select a communication scenario with the highest probability value from the second probability data as the current communication scenario.

[0037] As an optional implementation, in the second aspect of the embodiment of the present application, the adjusting unit comprises:

[0038] a first obtaining sub-unit, configured to obtain initial power grid protection setting value of a protection element in the current communication scenario;

[0039] a second obtaining sub-unit, configured to obtain the sum of currents at two ends of the protection element to determine ideal differential current value of the protection element;

[0040] a second determining sub-unit, configured to determine communication delay at two ends of the protection element according to the delay distribution information;

[0041] a third obtaining sub-unit, configured to obtain a sum of currents at both ends of the protection element in the communication time delay state, so as to determine an actual differential current value of the protection element;

[0042] a second calculating sub-unit, configured to subtract an initial differential current value from the actual differential current value, so as to calculate a delayed differential current value of the protection element;

[0043] a third calculating sub-unit, configured to add the delayed differential current value and the initial power distribution network protection setting value, so as to obtain an actual protection setting value;

[0044] an adjusting sub-unit, configured to adjust the initial power distribution network protection setting value to the actual protection setting value.

[0045] As an optional implementation, in the second aspect of the embodiment of the present application, the setting system further comprises:

[0046] a detecting unit, configured to detect whether the actual differential current value is greater than the actual protection setting value after the adjusting sub-unit adjusts the initial power distribution network protection setting value to the actual protection setting value;

[0047] a control unit, configured to control the protection element to perform a protection action when the detecting unit detects that the actual differential current value is greater than the actual protection setting value

[0048] The third aspect of the embodiment of the present application discloses a setting system, and the setting system comprises:

[0049] a memory in which executable program codes are stored;

[0050] a processor coupled with the memory;

[0051] The processor invokes the executable program codes stored in the memory, and executes the setting method of the power distribution network protection setting value disclosed in the first aspect of the embodiment of the present application.

[0052] The fourth aspect of the embodiment of the present application discloses a computer readable storage medium which stores a computer program, wherein the computer program causes a computer to execute the setting method of the power distribution network protection setting value disclosed in the first aspect of the embodiment of the present application.

[0053] The fifth aspect of the embodiment of the present application discloses a computer program product, which, when running on a computer, causes the computer to execute part or all steps of the setting method of the power distribution network protection setting value of the first aspect.

[0054] The sixth aspect of the embodiment of the present application discloses an application publishing platform, which is used for publishing a computer program product.

[0055] Compared with the prior art, the embodiment of the present application has the following beneficial effects:

[0056] In the embodiment of the present application, the sampling information delay data in different communication scenarios are obtained by simulation to form a simulation delay database; the current delay information is obtained by sampling delay compensation; the current communication scenario is determined from the simulation delay database according to the current delay information; the delay distribution information corresponding to the current communication scenario is obtained; and the delay distribution information is used to adjust the protection setting value of the power distribution network corresponding to the current communication scenario. It can be seen that the embodiment of the present application can adjust the action setting value of the networked protection, and achieve the effect of adaptive protection setting value and sampling synchronization condition. BRIEF DESCRIPTION OF DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0058] Figure 1 is a flowchart of a protection setting value setting method of a power distribution network disclosed by the embodiment of the present application;

[0059] Figure 2 is a flowchart of another protection setting value setting method of a power distribution network disclosed by the embodiment of the present application;

[0060] Figure 3 is a structure diagram of a setting system disclosed by the embodiment of the present application;

[0061] Figure 4 is a structure diagram of another setting system disclosed by the embodiment of the present application;

[0062] Figure 5 is a structure diagram of another setting system disclosed by the embodiment of the present application. DETAILED DESCRIPTION

[0063] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those ordinarily skilled in the art without creative effort belong to the scope of the present application.

[0064] It should be noted that the terms "first", "second", "third", "fourth" and the like in the specification and claims of the present application are used to distinguish different objects, and are not used to describe a particular order. The terms "include" and "have" and any variations thereof in the embodiments of the present application are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units need not be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to the process, method, product or device.

[0065] The embodiments of the present application disclose a setting method and a setting system for protection setting of a power distribution network, which can adjust the action setting value of networked protection and achieve the adaptive effect of protection setting value and sampling synchronization condition.

[0066] The embodiments will be described in detail below with reference to the accompanying drawings.

[0067] Embodiment one

[0068] Please refer to Figure 1 , Figure 1 is a flowchart of the setting method for protection setting of a power distribution network disclosed by the embodiments of the present application. As shown in Figure 1 , the setting method for protection setting of a power distribution network can include the following steps.

[0069] 101, the setting system simulates to obtain sampling information delay data under different communication scenarios, to form a simulation delay database.

[0070] As an optional implementation, in the embodiment of the application, the composition and the number of the communication scenarios can be determined in advance, that is, assuming that S(a, b, c) refers to a communication scenario determined by a, b, and c, and different combinations of a, b, and c will constitute a communication scenario. For example, if a, b, and c each have 3 kinds, that is, the network has 3 kinds of service configurations, 3 kinds of scheduling strategies, and 3 kinds of running events, there are 27 possible communication scenarios, which are S(a1, b1, c1), S(a1, b2, c1), S(a1, b3, c1), S(a1, b1, c2), S(a1, b1, c3), S(a1, b2, c2), S(a1, b2, c3), S(a1, b3, c2), S(a1, b3, c3); S(a2, b1, c1)...S(a2, b3, c3); S(a3, b1, c1)...S(a3, b3, c3). S(ai, bj, ck) is used to represent one of the scenarios, x, y, and z represent the number of a, b, and c respectively, and x can also represent that there are x service configurations in the system, and y and z are the same.

[0071] As an optional implementation, in the embodiment of the application, the application can simulate all possible scenarios of the intelligent power distribution network to obtain the corresponding sampling information delay and form a sampling information delay database.

[0072] As an optional implementation, in the embodiment of the application, at present, many simulation methods for communication simulation of power systems have emerged. The application is based on the service demand of power distribution network protection and uses OPNET communication software simulation as an example to state the technical points of the application, but is not limited to this simulation method. The application does not make any limitation.

[0073] As an optional implementation, in the embodiment of the application, the application can simulate the communication networking situation of the regional information transmission of the power distribution network protection system. In the process of building the communication simulation model, the sampling information size, sending frequency, and first sending mechanism of the communication network can be fully analyzed. At the same time, the flow situation of other information messages in the communication network and the importance level of the messages can be considered to establish a highly consistent communication simulation mapping with the actual system.

[0074] As an optional implementation, in the embodiment of the application, the following different scenarios can be considered when performing simulation:

[0075] (1) Differentiated service scenarios of the power distribution network: The application can consider the scenario model of multiple service forms, simulate different background service combination situations, and consider different business formats that may appear for different services, such as concurrent transmission of alarm time and high-frequency issuance of action instructions.

[0076] (2), the communication network difference scheduling scenario: the application can simulate different communication networking strategy, including unicast, multicast, broadcast transmission strategy, virtual local area network configuration scenario and software defined network operation scenario and scheduling conditions;

[0077] (3), network differentiation operation event: the application can simulate possible communication network fault conditions, including link break, network reconstruction, avalanche scale triggered by any node device exception; wherein the differentiated service and the differentiated scheduling condition determine the simulation scene requirement according to the configuration condition, and the differentiated operation event needs to be predicted and the actual event form is analyzed.

[0078] 102, the setting system obtains the current delay information through sampling delay compensation.

[0079] As an optional implementation, in the embodiment of the application, the application can obtain the sampling information delay data by the aid of sampling delay compensation technology.

[0080] 103, the setting system determines the current communication scene from the simulation delay database according to the current delay information.

[0081] As an optional implementation, in the embodiment of the application, the application can obtain the scene corresponding to the current delay information and the delay data corresponding to the scene from the simulation delay database, and then can quantize according to the size of the maximum value and the minimum value using normal distribution, considering that the maximum value is the average delay plus 3σ, and the minimum value is the average delay minus 3σ. Thus, under the scene (a, b, c), the probability of the delay of the sampling information is p a,b,c (T1), p a,b,c (T2),..., p a,b,c (T n ), and the application can obtain the sampling information by the existing delay compensation strategy, and can obtain the delay size of this part of the sampling information, and evaluate the possibility of each communication scene as the current communication scene by combining the probability of this part of the sampling information under each scene, and the evaluation method can be determined by the following formula

[0082]

[0083] Wherein, alpha (a i ,b j ,c k ) can represent the possibility of the communication scene being s (a i ,b j ,c k), m represents any set of sampling information with sampling information delay compensation capability that networked protection can obtain, M represents the total number of the above information. Tm represents the actual delay size of the sampling information. Thus, by comparing the size of the possibility of different communication scenarios, the most possible communication scenario is obtained as the current communication scenario.

[0084] 104. The setting system obtains delay distribution information corresponding to the current communication scenario.

[0085] As an optional implementation, in the embodiment of the application, the current system is determined to be in a communication scenario through part of the collected sampling information, and then global sampling information delay data of the current system is obtained from the sampling information experimental data of all scenarios in the simulation delay database.

[0086] 105. The setting system adjusts the protection setting value of the power distribution network corresponding to the current communication scenario according to the delay distribution information.

[0087] As an optional implementation, in the embodiment of the application, the core idea of the application is to determine the current communication scenario through part of the sampling information that can be obtained by the delay compensation strategy, and when the communication scenario is determined, the delay compensation data of the global information can be obtained through the sampling information delay database under the scenario.

[0088] As an optional implementation, in the embodiment of the application, first, the sampling information interaction delay of different scenarios is obtained by simulating different communication scenarios, and the corresponding sampling information delay database for different communication scenarios is formed. Second, the sampling information delay data that can be obtained by networked protection is obtained with the aid of the sampling delay compensation technology, the communication scenario in which the current system is located is determined, the sampling information packet delay distribution of the whole system is obtained from the sampling information delay database of the simulation result, and finally, the sampling information delay condition is converted into the action setting value increment of the protection, and the delay automatic setting of the protection for different communication scenarios is realized.

[0089] As an optional implementation, in the embodiment of the application, the sampling delay distribution under different communication scenarios can be obtained, and the measurable sampling information delay can also be obtained through the existing delay compensation method. The current possible communication scenario is obtained by combining the simulation result of different communication scenarios with the part of the measurable sampling information delay, and the actual sampling information delay distribution is determined, and the action setting value of the networked protection is adjusted, and the effect of adaptive protection setting value according to the sampling synchronization condition is obtained.

[0090] As an optional implementation, in this embodiment of the invention, differential protection determines the protection action by comparing whether the differential current measured at both ends at the same time is greater than a certain threshold (protection setting). However, due to the existence of communication delay, the current measurement values ​​at both ends have a time difference. This is equivalent to using the current at time T1 and the current at time T2 for differential calculation, which will lead to inaccurate calculation results and cause the protection to maloperate or fail to operate. Therefore, if we can determine this delay, we can use the current difference caused by the delay to compensate for the operating current, thereby avoiding the protection from maloperating or failing to operate.

[0091] As an optional implementation, in this embodiment of the invention, the delay distribution is different in different communication scenarios. This application can determine the communication scenario, then determine the delay distribution in that scenario, and dynamically adjust the protection setting of the protection device accordingly.

[0092] exist Figure 1 The method for setting distribution network protection settings is described using the setting system as the executing entity as an example. It should be noted that... Figure 1 The execution subject of the distribution network protection setting method shown can also be an independent device associated with the setting system, which is not limited in the embodiments of the present invention.

[0093] It is evident that implementation Figure 1 The described method for setting the protection settings of a distribution network can adjust the action settings of networked protection to achieve the effect of adaptive adjustment between the protection settings and the sampling synchronization conditions.

[0094] In addition, implementation Figure 1 The described method for setting protection settings in a distribution network can optimize protection performance to the greatest extent possible based on synchronization delay conditions.

[0095] Example 2

[0096] Please see Figure 2 , Figure 2 This is a flowchart illustrating another method for setting distribution network protection settings according to an embodiment of the present invention. Figure 2 As shown, the method for setting the protection settings of this distribution network may include the following steps:

[0097] 201. The system simulation is used to obtain the sampling information delay data under different communication scenarios to form a simulation delay database.

[0098] 202. The tuning system obtains the current delay information by sampling delay compensation.

[0099] 203. The tuning system determines candidate communication scenarios containing current delay information from the simulation delay database.

[0100] 204、the setting system normalizes the sampling information delay data in each candidate communication scenario to obtain first probability data of the current delay information appearing in each candidate communication scenario.

[0101] 205、the setting system divides each first probability data by the sum of the probability data to calculate second probability data of each candidate communication scenario being the current communication scenario.

[0102] 206、the setting system selects the communication scenario with the highest probability value from the second probability data as the current communication scenario.

[0103] As an optional implementation, in the embodiment of the application, each piece of information has a fluctuation range, i.e. a maximum value and a minimum value, in a communication scenario, and the probability of the sampling information 1 in the fluctuation range of scenario 1 is in accordance with a normal distribution.

[0104] For example, the fluctuation range of the sampling information 1 in scenario 1 is (1ms-3ms), and according to the normal distribution, the probability of the sampling information 1 delay being 1ms and 3ms in this scenario is 0.003, the probability of the delay being 2ms is 0.5, and the probability of the delay being 2.5ms is 0.35. Similarly, the fluctuation range of the sampling information 1 in scenario 2 is (2ms-4ms), and according to the same principle, the probability of the delay being 2ms and 4ms in this scenario is 0.003, the probability of the delay being 3ms is 0.5, and the probability of the delay being 2.5ms is 0.3. If the collected sampling information 1 delay is 2ms, it is obvious that the communication scenario is scenario 1 with a high probability.

[0105] For another example, if other extreme probabilities occur, it is also possible that the probability of the collected information delay in different scenarios is relatively close, for example, the collected delay is 2.5ms, and the current most possible communication scenario can be determined according to the formula , i.e. two communication scenarios, one piece of information containing delay is 2ms. According to the formula , the probability of scenario 1 α(a i ,b j ,c k ) is , and the probability of scenario 2 α(a i ,b j ,c k ) is It is obvious that the current communication scenario is scenario 1.

[0106] 207、the setting system obtains delay distribution information corresponding to the current communication scenario.

[0107] 208. The setting system obtains the initial distribution network protection settings of the protection elements under the current communication scenario.

[0108] 209. The setting system obtains the sum of the currents across the protection element to determine the ideal differential current value of the protection element.

[0109] 210. The setting system determines the communication delay at both ends of the protection element based on the delay distribution information.

[0110] 211. The setting system obtains the sum of the currents at both ends of the protection element under the communication delay state in order to determine the actual differential current value of the protection element.

[0111] 212. The setting system subtracts the initial differential current value from the actual differential current value to calculate the delay differential current value of the protection element.

[0112] 213. The setting system adds the delay differential current value to the initial distribution network protection setting value to obtain the actual protection setting value.

[0113] 214. The setting system adjusts the initial protection settings of the distribution network to the actual protection settings.

[0114] As an optional implementation, in this embodiment of the invention, under normal circumstances, the original setting system sets a set value for the protection element. When the protection element detects that the sum of the currents at both ends is greater than this initial value, it will issue an action signal. However, this set value is a fixed value given under ideal conditions. Due to the existence of communication delay, the sum of the currents at both ends will have a deviation. That is to say, at that moment, it should be... However, due to communication delays, the actual criterion calculation is performed according to... This process, obviously, will increase the current deviation ΔI caused by the time delay. r Therefore, this application requires adjustment of the initial setting value to compensate for the current deviation caused by the time delay.

[0115] For example: Suppose the setting system sets a set value Id = 10A for the protective element. If a fault occurs at a certain moment t1, theoretically, the current at both ends at the same moment will be... However, due to communication delays, the following will be obtained: If the original setting Id = 10A is maintained, it will be found that 8 is less than 10, which will lead to the assumption that there is no fault, and the protection will not operate, resulting in a failure to operate. Therefore, this application allows for adjusting the setting value to Id for this communication scenario. r +ΔI r (s)=10A+(-5A)=5A, and 8 is greater than 5, so the protection element can correctly identify the fault and execute the protection action.

[0116] 215. The setting system checks whether the actual differential current value is greater than the actual protection setting value. If yes, proceed to step 216; otherwise, end the process.

[0117] 216. The setting system controls the protective elements to perform protective actions.

[0118] As an optional implementation, in this embodiment of the invention, if the actual differential current value is not greater than the actual protection setting value, the setting system can consider that the current at both ends of the protection element has not exceeded the limit differential current value, that is, the power grid is in a safe state at this time.

[0119] As an optional implementation, in this embodiment of the invention, this application can be used and These represent the secondary current and differential current across any protection element in the networked protection system, respectively. Braking current Under the condition of having sampling information compensation, set the differential protection floating threshold ΔI corresponding to the maximum delay compensation value in the relevant scenario. r (s)=f(T m (s)), so the differential protection judges the fault in the following way, where s represents the current scenario, and then the actual protection setting I can be obtained. d ≥I r +ΔI r (s).

[0120] As an optional implementation, in this embodiment of the invention, if not all sampled information has delay measurement results, this application can analyze the possible operating scenario based on the delay magnitude of the terminal to obtain the current possible scenario s', supplement the sampled information values ​​that do not have sampling compensation conditions in this scenario, and recalculate the differential protection floating threshold ΔI. r (s')=f(T max (s')), thereby protecting the system from operating according to the updated settings, and thus obtaining the actual protection settings I. d ≥I r +ΔI r (s').

[0121] It is evident that implementation Figure 2 The described alternative method for setting distribution network protection settings can adjust the action settings of networked protection to achieve an adaptive effect between protection settings and sampling synchronization conditions.

[0122] In addition, implementation Figure 2 The described alternative method for setting distribution network protection settings can achieve maximum optimization of protection performance based on synchronization delay conditions.

[0123] Example 3

[0124] Please refer to Figure 3 , Figure 3 is a structure diagram of the setting system disclosed by the embodiment of the application. As shown in the figure, the setting system 300 can include a simulation unit 301, a first acquisition unit 302, a determination unit 303, a second acquisition unit 304 and an adjustment unit 305, wherein: Figure 3

[0125] The simulation unit 301 is configured to simulate to obtain sampling information delay data in different communication scenarios, so as to form a simulation delay database.

[0126] The first acquisition unit 302 is configured to acquire current delay information through sampling delay compensation.

[0127] The determination unit 303 is configured to determine a current communication scenario from the simulation delay database according to the current delay information.

[0128] The second acquisition unit 304 is configured to acquire delay distribution information corresponding to the current communication scenario.

[0129] The adjustment unit 305 is configured to adjust power distribution network protection setting value corresponding to the current communication scenario according to the delay distribution information.

[0130] As an optional implementation, in the embodiment of the application, the composition parts of the communication scenario and the number of the composition parts can be determined in advance, that is, assuming that S(a, b, c) refers to a communication scenario determined by a, b and c, and different combinations of a, b and c will form a communication scenario. For example, if a, b and c each have 3 kinds, that is, the power distribution network has 3 kinds of service configurations, 3 kinds of scheduling strategies and 3 kinds of running events, there are 27 possible communication scenarios, which are S(a1, b1, c1), S(a1, b2, c1), S(a1, b3, c1), S(a1, b1, c2), S(a1, b1, c3), S(a1, b2, c2), S(a1, b2, c3), S(a1, b3, c2), S(a1, b3, c3); S(a2, b1, c1)…S(a2, b3, c3); S(a3, b1, c1)…S(a3, b3, c3). S(ai, bj, ck) is used to represent one of the scenarios, x, y and z respectively represent the number of a, b and c, and x can also represent that there are x service configurations in the system, and y and z are the same.

[0131] As an optional implementation, in the embodiment of the application, the simulation unit 301 can simulate all possible scenarios of the intelligent power distribution network through simulation, acquire corresponding sampling information delay and form a sampling information delay database.

[0132] ​As an optional implementation, in the embodiment of the application, at present, many simulation methods emerge for communication simulation of power systems, the simulation unit 301 is for the service demand of power distribution network protection, and for example, the technical points of the application are stated by taking OPNET communication software simulation as an example, but the application is not limited to this simulation mode, and the application does not make any limitation.

[0133] As an optional implementation, in the embodiment of the application, the simulation unit 301 can simulate the communication networking of power distribution network protection system regional information transmission, in the process of building a communication simulation model, the sampling information size, sending frequency, first sending mechanism and the like of the communication network can be fully analyzed, meanwhile, the flow of other information messages in the communication network and the importance level of the messages can be considered, and a communication simulation mapping highly consistent with the actual system is established.

[0134] As an optional implementation, in the embodiment of the application, when the simulation unit 301 performs simulation, the following different scenarios can be considered.

[0135] (1) Differentiated service scenarios of power distribution networks: the application can consider a scenario model of multiple service forms, simulate different background service combination conditions, and consider different business formats that can appear, such as concurrent transmission of alarm time and high-frequency issuance of action instructions.

[0136] (2) Differentiated scheduling scenarios of communication networks: the application can simulate different communication networking strategies, including unicast, multicast, broadcast and other sending strategies, virtual local area network configuration scenarios, and scheduling conditions of software-defined network operation scenarios.

[0137] (3) Differentiated running events of networks: the application can simulate possible communication network fault conditions, including link disconnection, network reconstruction, and avalanche scale caused by abnormality of any node device; the differentiated service and the differentiated scheduling condition determine the simulation scenario requirement according to the configuration condition, and the differentiated running event needs to be predicted and analyzed according to the actual event form.

[0138] As an optional implementation, in the embodiment of the application, the first acquisition unit 302 can obtain the sampling information delay data by the aid of the sampling delay compensation technology.

[0139] As an optional implementation, in the embodiment of the application, the application can obtain the scenario corresponding to the current delay information and the delay data corresponding to the scenario from the simulation delay database, and then quantize by using normal distribution according to the size of the maximum value and the minimum value, considering that the maximum value is the average delay plus 3σ and the minimum value is the average delay minus 3σ. Thus, the probabilities of the delay of the sampling information under the scenario (a, b, c) are p a,b,c (T1), p a,b,c(T2),...,p a,b,c (T n ), and the determining unit 303 can obtain the sampling information by the existing delay compensation strategy, and can obtain the delay size of the part of the sampling information according to the sampling information, and evaluate the possibility of each communication scenario as the current communication scenario in combination with the probability of the part of the sampling information in each scenario, and the evaluation manner can be determined by the following formula

[0140]

[0141] Wherein, α(a i ,b j ,c k ) can represent the possibility of the communication scenario as s(a i ,b j ,c k ), m represents any one group of sampling information with delay compensation capability of the sampling information that the network protection can obtain, M represents the total number of the above information. Tm represents the actual delay size of the sampling information. Therefore, by comparing the possibility of different communication scenarios, the most possible communication scenario is obtained as the current communication scenario.

[0142] As an optional implementation, in the embodiment of the application, the determining unit 303 can determine the communication scenario in which the current system is located through part of the sampling information collected, and then obtain the global sampling information delay data of the current system from the sampling information experimental data of all scenarios in the simulation delay database.

[0143] As an optional implementation, in the embodiment of the application, the core idea of the application is that the first acquisition unit 302 determines the current communication scenario through part of the sampling information that can be truly obtained by the delay compensation strategy, and when the communication scenario is determined, the second acquisition unit 304 can obtain the delay compensation data of the global information through the sampling information delay database in the scenario.

[0144] As an optional implementation, in the embodiment of the application, first, the simulation unit 301 can obtain the sampling information interaction delay of different scenarios by simulating different communication scenarios, form the corresponding sampling information delay database for different communication scenarios, second, the first acquisition unit 302 can obtain the sampling information delay data that the network protection can obtain with the aid of the sampling delay compensation technology, the determining unit 303 can determine the communication scenario in which the current system is located, the second acquisition unit 304 can obtain the sampling information packet delay distribution of the whole system from the sampling information delay database of the simulation result, and finally, the adjusting unit 305 can convert the sampling information delay into the action setting value increment of the protection, so as to realize the delay automatic setting of the protection in response to different communication scenarios.

[0145] As an optional implementation, in this embodiment of the invention, the simulation unit 301 can acquire the sampling delay distribution under different communication scenarios. At the same time, the first acquisition unit 302 can also acquire measurable sampling information delay through existing delay compensation methods. The determination unit 303 can use this part of the measurable sampling information delay, combined with the simulation results of different communication scenarios, to acquire the current possible communication scenario. Then, the second acquisition unit 304 can determine the actual sampling information delay distribution. The adjustment unit 305 adjusts the action setting value of the networked protection accordingly, so as to achieve the effect of adaptive protection setting value according to sampling synchronization conditions.

[0146] As an optional implementation, in this embodiment of the invention, differential protection determines the protection action by comparing whether the differential current measured at both ends at the same time is greater than a certain threshold (protection setting). However, due to the existence of communication delay, the current measurement values ​​at both ends have a time difference. This is equivalent to using the current at time T1 and the current at time T2 for differential calculation, which will lead to inaccurate calculation results and cause the protection to maloperate or fail to operate. Therefore, if we can determine this delay, we can use the current difference caused by the delay to compensate for the operating current, thereby avoiding the protection from maloperating or failing to operate.

[0147] As an optional implementation, in this embodiment of the invention, the delay distribution is different in different communication scenarios. This application can determine the communication scenario, then determine the delay distribution in that scenario, and dynamically adjust the protection setting of the protection device accordingly.

[0148] It is evident that implementation Figure 3 The described setting system can adjust the action setting value of networked protection to achieve the effect of adaptive protection setting value and sampling synchronization condition.

[0149] In addition, implementation Figure 3 The described tuning system can optimize protection performance to the greatest extent possible based on the synchronization delay.

[0150] Example 4

[0151] Please see Figure 4 , Figure 4 This is a schematic diagram of another tuning system disclosed in an embodiment of the present invention. Figure 4 The tuning system shown is composed of Figure 3 The tuning system shown is obtained through optimization. Figure 3 Compared to the tuning system shown, Figure 4 The determining unit 303 shown includes:

[0152] The first determining sub-unit 3031 is configured to determine a candidate communication scenario containing current delay information from the simulation delay database.

[0153] The normal distribution sub-unit 3032 is configured to perform normal distribution on the sampling information delay data in each candidate communication scenario to obtain first probability data of the current delay information in each candidate communication scenario.

[0154] The first calculating sub-unit 3033 is configured to divide each first probability data by the sum of the probability data to calculate second probability data of each candidate communication scenario being the current communication scenario.

[0155] The selecting sub-unit 3034 is configured to select the communication scenario with the highest probability value from the second probability data as the current communication scenario.

[0156] As an optional implementation, in the embodiment of the application, each piece of information has a fluctuation range, i.e., a maximum value and a minimum value, of information delay in a communication scenario. The fluctuation range of sampling information 1 in scenario 1 is min-max, and the probability in the range conforms to the normal distribution described in the figure.

[0157] For example, the fluctuation range of sampling information 1 in scenario 1 is (1ms-3ms), and according to the normal distribution, the probability of the delay of sampling information 1 being 1ms and 3ms in this scenario is 0.003, the probability of being 2ms is 0.5, and the probability of being 2.5ms is 0.35. Similarly, the fluctuation range of sampling information 1 in scenario 2 is (2ms-4ms), and according to the same principle, the probability of the delay being 2ms and 4ms in this scenario is 0.003, the probability of being 3ms is 0.5, and the probability of being 2.5ms is 0.3. If the delay of the collected sampling information 1 is 2ms, it is obvious that the communication scenario is scenario 1 with a large probability.

[0158] For another example, if other extreme probabilities occur, it is also possible that the probability of the delay of the collected information in different scenarios is relatively close, for example, the collected delay is 2.5ms. According to the formula , the current most possible communication scenario can be determined, i.e., two communication scenarios and one piece of information containing delay is 2ms. According to the formula , the probability of scenario 1 α(a i ,b j ,c k ) is , and the probability of scenario 2 α(a i ,b j ,c k ) is It is obvious that the current communication scenario is scenario 1.

[0159] and Figure 3 Compared to the tuning system shown, Figure 4 The adjustment unit 305 shown includes:

[0160] The first acquisition subunit 3051 is used to acquire the initial distribution network protection settings of the protection elements under the current communication scenario.

[0161] The second acquisition subunit 3052 is used to acquire the sum of the currents across the protection element in order to determine the ideal differential current value of the protection element.

[0162] The second determining subunit 3053 is used to determine the communication delay at both ends of the protection element based on the delay distribution information.

[0163] The third acquisition subunit 3054 is used to acquire the sum of the currents at both ends of the protection element under the communication delay state, so as to determine the actual differential current value of the protection element.

[0164] The second calculation subunit 3055 is used to subtract the initial differential current value from the actual differential current value to calculate the delayed differential current value of the protection element.

[0165] The third calculation subunit 3056 is used to add the delayed differential current value to the initial distribution network protection setting value to obtain the actual protection setting value.

[0166] Adjustment subunit 3057 is used to adjust the initial distribution network protection settings to the actual protection settings.

[0167] As an optional implementation, in this embodiment of the invention, under normal circumstances, the original setting system sets a set value for the protection element. When the protection element detects that the sum of the currents at both ends is greater than this initial value, it will issue an action signal. However, this set value is a fixed value given under ideal conditions. Due to the existence of communication delay, the sum of the currents at both ends will have a deviation. That is to say, at that moment, it should be... However, due to communication delays, the actual criterion calculation is performed according to... This process, obviously, will increase the current deviation ΔI caused by the time delay. r Therefore, this application requires adjustment of the initial setting value to compensate for the current deviation caused by the time delay.

[0168] For example: Suppose the setting system sets a set value Id = 10A for the protective element. If a fault occurs at a certain moment t1, theoretically, the current at both ends at the same moment will be... However, due to communication delays, the following will be obtained: If the original setting value I d = 10A is still used, it will be found that 8 is less than 10, and it will be considered that there is no fault, and the protection will not act, and the rejection will occur. Therefore, the application can adjust the setting value for this communication scene to I r + ΔI r (s) = 10A + (-5A) = 5A, and 8 is greater than 5, and the protection element can correctly judge the fault and execute the protection action.

[0169] Compared with the setting system shown in Figure 3 , the setting system shown in Figure 4 may further include:

[0170] The detection unit 306 is configured to detect whether the actual differential current value is greater than the actual protection setting value after the adjustment subunit 3057 adjusts the initial power distribution network protection setting value to the actual protection setting value.

[0171] The control unit 307 is configured to control the protection element to execute the protection action when the detection unit 306 detects that the actual differential current value is greater than the actual protection setting value.

[0172] As an optional implementation, in the embodiment of the application, if the detection unit 306 detects that the actual differential current value is not greater than the actual protection setting value, the setting system can consider that the current at both ends of the protection element does not exceed the limited differential current value, that is, the power grid is in a safe state at this time.

[0173] As an optional implementation, in the embodiment of the application, the application can use and to respectively represent the secondary current at both ends of any protection element of the networked protection, and the differential current braking current Under the condition of having the sampling information compensation, the differential protection floating threshold corresponding to the maximum time delay compensation value in the scene is set as ΔI r (s) = f(T m (s)), so that the differential protection judges the fault in the following manner: s represents the current scene, and then the actual protection setting value I d ≥ I r + ΔI r (s).

[0174] As an optional implementation, in the embodiment of the application, if not all sampling information has the time delay measurement result, the application can analyze the current possible running scene according to the time delay size of the terminal, that is, the current possible scene s' can be obtained, the sampling information value size of the scene without the sampling compensation condition is supplemented, and the differential protection floating threshold ΔI r (s') = f(T max(s'), so as to protect according to the updated fixed value, and then the actual protection fixed value I d ≥I r +ΔI r (s').

[0175] It can be seen that the implementation Figure 4 of the described another setting system can adjust the action fixed value size of the networked protection, and achieve the effect of protection fixed value and sampling synchronization condition adaptation.

[0176] In addition, the implementation Figure 4 of the described another setting system can realize the maximum optimization of protection performance according to the synchronization delay condition.

[0177] Embodiment five

[0178] Please refer to Figure 5 , Figure 5 is another structure diagram of the setting system disclosed by the embodiment of the application. As shown in the figure, the setting system can include: Figure 5

[0179] a memory 501 storing executable program codes;

[0180] a processor 502 coupled with the memory 501;

[0181] wherein the processor 502 calls the executable program codes stored in the memory 501 to execute Figures 1-2 any one of the setting methods of the power distribution network protection fixed value.

[0182] The embodiment of the application discloses a computer readable storage medium which stores a computer program, wherein the computer program makes the computer execute Figures 1-2 any one of the setting methods of the power distribution network protection fixed value.

[0183] The embodiment of the application further discloses a computer program product, wherein when the computer program product runs on the computer, it makes the computer execute part or all steps of the method in the above method embodiments.

[0184] ​Those skilled in the art can understand that all or part of the steps of various methods of the above embodiments can be completed by instructing the relevant hardware by a program, and the program can be stored in a computer readable storage medium, including a Read-Only Memory (ROM), a Random Access Memory (RAM), a Programmable Read-only Memory (PROM), an Erasable Programmable Read Only Memory (EPROM), a One-time Programmable Read-Only Memory (OTPROM), an Electrically-Erasable Programmable Read-Only Memory (EEPROM), a Compact Disc Read-Only Memory (CD-ROM) or other optical disk memories, magnetic disk memories, magnetic tape memories, or any other medium readable by a computer and capable of carrying or storing data.

[0185] The above describes in detail the setting method and setting system for the protection setting value of the power distribution network according to the embodiments of the present application. The principles and implementation manners of the present application are described by using specific examples. The above description of the embodiments is only used to help understand the method of the present application and its core idea. Meanwhile, for those skilled in the art, the specific implementation manners and application ranges can be changed according to the idea of the present application. In conclusion, the content of the present description should not be understood as a limitation of the present application.

Claims

1. A method for setting the protection setting of a power distribution network, characterized in that, The method comprises: obtaining sampling information delay data under different communication scenarios through simulation to form a simulation delay database; obtaining current delay information through sampling delay compensation; determining a current communication scenario from the simulation delay database according to the current delay information; obtaining delay distribution information corresponding to the current communication scenario; adjusting power grid protection setting value corresponding to the current communication scenario according to the delay distribution information.

2. The method of claim 1, wherein, The determining of the current communication scenario from the simulation delay database according to the current delay information comprises: determining candidate communication scenarios containing the current delay information from the simulation delay database; performing normal distribution on the sampling information delay data in each candidate communication scenario to obtain first probability data of occurrence of the current delay information in each candidate communication scenario; dividing each first probability data by the sum of the probability data to obtain second probability data of each candidate communication scenario being the current communication scenario; selecting a communication scenario with the highest probability value from the second probability data as the current communication scenario.

3. The method according to claim 1 or 2, characterized in that, The adjusting of the power grid protection setting value corresponding to the current communication scenario according to the delay distribution information comprises: obtaining initial power grid protection setting value of a protection element under the current communication scenario; obtaining the sum of currents at both ends of the protection element to determine an ideal differential current value of the protection element; determining communication delay at both ends of the protection element according to the delay distribution information; obtaining the sum of currents at both ends of the protection element under the communication delay state to determine an actual differential current value of the protection element; subtracting the actual differential current value from the initial differential current value to obtain a delay differential current value of the protection element; adding the delay differential current value and the initial power grid protection setting value to obtain an actual protection setting value; adjusting the initial power grid protection setting value to the actual protection setting value.

4. The method of claim 3, wherein, After the initial power grid protection setting value is adjusted to the actual protection setting value, the method further comprises: detecting whether the actual differential current value is greater than the actual protection setting value; if yes, controlling the protection element to perform a protection action.

5. A setting system characterized by, The setting system comprises: a simulation unit configured to obtain sampling information delay data under different communication scenarios through simulation to form a simulation delay database; a first obtaining unit configured to obtain current delay information through sampling delay compensation; a determining unit configured to determine a current communication scenario from the simulation delay database according to the current delay information; a second obtaining unit configured to obtain delay distribution information corresponding to the current communication scenario; an adjusting unit configured to adjust power grid protection setting value corresponding to the current communication scenario according to the delay distribution information.

6. The setting system of claim 5, wherein, The determining unit comprises: a first determining subunit configured to determine candidate communication scenarios containing the current delay information from the simulation delay database; a normal distribution subunit, configured to perform normal distribution on the sampling information delay data in each of the candidate communication scenarios to obtain first probability data of occurrence of the current delay information in each of the candidate communication scenarios; a first calculation subunit, configured to divide each of the first probability data by a sum of the probability data to obtain second probability data of each of the candidate communication scenarios being the current communication scenario; a selection subunit, configured to select a communication scenario with the highest probability value from the second probability data as the current communication scenario.

7. The setting system according to claim 5 or 6, characterized in that The adjusting unit comprises: a first acquisition subunit, configured to acquire an initial protection setting value of a protection element in the current communication scenario; a second acquisition subunit, configured to acquire a sum of currents at two ends of the protection element to determine an ideal differential current value of the protection element; a second determination subunit, configured to determine a communication delay at the two ends of the protection element according to the delay distribution information; a third acquisition subunit, configured to acquire a sum of the currents at the two ends of the protection element in the communication delay state to determine an actual differential current value of the protection element; a second calculation subunit, configured to subtract the actual differential current value from the initial differential current value to obtain a delay differential current value of the protection element; a third calculation subunit, configured to add the delay differential current value and the initial protection setting value to obtain an actual protection setting value; an adjusting subunit, configured to adjust the initial protection setting value of the power distribution network to the actual protection setting value.

8. The setting system of claim 7, wherein, The setting system further comprises: a detection unit, configured to detect whether the actual differential current value is greater than the actual protection setting value after the adjusting subunit adjusts the initial protection setting value of the power distribution network to the actual protection setting value; a control unit, configured to control the protection element to perform a protection action when the detection unit detects that the actual differential current value is greater than the actual protection setting value.

9. A setting system characterized by, The setting system comprises: a memory storing executable program codes; a processor coupled with the memory; the processor invokes the executable program codes stored in the memory to execute the setting method of the protection setting value of the power distribution network according to any one of claims 1-4.

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