A method and device for searching transient control measures of a power system

Abstract

The application discloses a kind of transient control measure search method and device of power system, wherein method includes: according to multiple expected faults of power system and multiple operating modes, the optimal transient control strategy of each expected fault under each operating mode is generated;According to the first stability control degree of each expected fault under each operating mode obtained by preset stability control degree index;According to the current load level when system occurs input fault, the system load level corresponding to each operating mode determines the interval of current operating mode, and the second stability control degree of input fault under current operating mode is determined according to the first stability control degree and interval;According to the first stability control degree and the second stability control degree, the approximate expected fault of input fault is determined, and the optimal transient control strategy of approximate expected fault under corresponding operating mode is used to determine the transient control measure of input fault.The application can quickly and accurately determine the transient control measure of input fault.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system, and particularly relates to a transient control measure searching method and device for a power system. BACKGROUND

[0002] With the increasing capacity of power systems, the power grid develops towards extra-high voltage power transmission and cross-regional interconnection, and the requirements for safe and stable, flexible and efficient operation control are increasing. The development of modern power systems makes the stability problem increasingly important, and transient stability control is an important aspect of interconnection system stability research.

[0003] However, the existing transient control measure searching method is usually difficult to balance high efficiency and high accuracy. SUMMARY

[0004] The present application relates to the technical field of power system, and particularly relates to a transient control measure searching method and device for a power system.

[0005] The technical problems to be solved by the present application are as follows:

[0006] A transient control measure searching method for a power system, comprising:

[0007] Generating an optimal transient control strategy for each of a plurality of expected faults under each of a plurality of operating modes according to the plurality of expected faults and the plurality of operating modes, the plurality of operating modes including a typical operating mode, a limit operating mode, and a plurality of intermediate operating modes between the typical operating mode and the limit operating mode;

[0008] Obtaining a first stability control strength of each of the expected faults under each of the operating modes according to a preset stability control strength index, the first stability control strength reflecting the severity of the expected fault on the transient stability of the power system;

[0009] Determining a belonging interval of a current operating mode according to a current load level when the system has an input fault and a system load level corresponding to each of the operating modes, determining a second stability control strength of the input fault under the current operating mode according to the first stability control strength and the belonging interval, the second stability control strength reflecting the severity of the input fault on the transient stability of the power system;

[0010] Determining an approximate expected fault of the input fault according to the first stability control strength and the second stability control strength, determining a transient control measure of the input fault according to the optimal transient control strategy of the approximate expected fault under the corresponding operating mode, the difference between the first stability control strength and the second stability control strength of the approximate expected fault under a certain operating mode being not greater than a preset threshold.

[0011] Optionally, generating the optimal transient control strategy of each of the contingency faults under each of the operating modes according to a plurality of contingency faults and a plurality of operating modes of the power system comprises:

[0012] calculating the sensitivity of each of the contingency faults to different control measures according to a preset sensitivity index;

[0013] generating a plurality of control measure clusters by clustering the sensitivity according to the electrical distance between the corresponding units and loads of different control measures, and calculating the unit tripping parameters and load shedding parameters of each of the control measure clusters under each of the operating modes;

[0014] calculating the comprehensive fitness of each of the contingency faults according to the unit tripping parameters and load shedding parameters, and generating the optimal transient control strategy of each of the contingency faults under each of the operating modes with the minimum comprehensive fitness as the optimization objective.

[0015] Optionally, calculating the sensitivity of each of the contingency faults to different control measures according to a preset sensitivity index comprises:

[0016] for each of the contingency faults i, calculating the sensitivity of different control measures j based on different units and loads according to

[0017] wherein, S ij represents the sensitivity of the contingency fault i to the control measure j, f ij (w) represents the difference in voltage or power angle stability level before and after the action of the control measure after the occurrence of the contingency fault i; g ij (v) represents the load change amount of the node.

[0018] Optionally, the unit tripping parameters are the number of trippable generator nodes and the trippable unit amount of each generator node.

[0019] Optionally, the load shedding parameters are the number of trippable load nodes and the trippable load amount of each load node.

[0020] Optionally, the comprehensive fitness is:

[0021]

[0022] wherein, D i is the comprehensive fitness of the contingency fault i, N G is the number of trippable generator nodes; N L is the number of trippable load nodes; ΔP G,a is the trippable unit amount of the a-th generator node; ΔP L,b is the trippable load amount of the b-th load node; α and β are weight coefficients; u a and u​b is a control variable for cutting machine quantity and cutting load quantity respectively; u a is a discrete integer, u a is equal to 1, indicating that the bus a cutting machine acts, u a is equal to 0, indicating that the bus a cutting machine does not act, a = 1, 2,..., N G ;u b is a continuous variable in [0, 1], b = 1, 2,..., N L ;

[0023] Optionally, the second stability control degree of the input fault in the current operation mode is determined according to the first stability control degree and the corresponding interval.

[0024] According to the first stability control degree and the corresponding interval, the second stability control degree of the input fault in the current operation mode is determined by using a cubic spline interpolation method.

[0025] Optionally, the transient control measure of the input fault is determined according to the optimal transient control strategy of the approximate expected fault in the corresponding operation mode.

[0026] The optimal transient control strategy of the approximate expected fault in the corresponding operation mode is taken as the transient control measure of the input fault.

[0027] The application also provides a transient control measure searching device for a power system, comprising:

[0028] An optimal transient control strategy determination module is configured to generate optimal transient control strategies of a plurality of expected faults in a plurality of operation modes according to the expected faults and the operation modes, wherein the operation modes include a typical operation mode, a limit operation mode and a plurality of intermediate operation modes between the typical operation mode and the limit operation mode.

[0029] A first stability control degree calculation module is configured to obtain first stability control degrees of the expected faults in the operation modes according to preset stability control degree indexes, wherein the first stability control degrees reflect the severity of the expected faults on the transient stability of the power system.

[0030] A second stability control degree determination module is configured to determine a corresponding interval of a current operation mode according to a current load level when the system has an input fault and system load levels corresponding to the operation modes, and to determine a second stability control degree of the input fault in the current operation mode according to the first stability control degree and the corresponding interval, wherein the second stability control degree reflects the severity of the input fault on the transient stability of the power system.

[0031] The transient control measure determination module is configured to determine an approximate expected fault of the input fault according to the first stability control strength and the second stability control strength, and determine a transient control measure of the input fault according to an optimal transient control strategy of the approximate expected fault in a corresponding operating mode, wherein a difference between the first stability control strength and the second stability control strength of the approximate expected fault in a certain operating mode is not greater than a preset threshold.

[0032] Optionally, the optimal transient control strategy determination module generates the optimal transient control strategy of each expected fault in each operating mode according to a plurality of expected faults and a plurality of operating modes of the power system, and the method comprises the following steps.

[0033] The optimal transient control strategy determination module calculates the sensitivity of each expected fault to different control measures according to a preset sensitivity index.

[0034] A plurality of control measure clusters are generated by clustering the sensitivity according to the electrical distance between the corresponding units and loads of different control measures, and the parameters of the units and the parameters of the loads are calculated in each operating mode.

[0035] The optimal transient control strategy determination module calculates the comprehensive fitness of each expected fault according to the parameters of the units and the parameters of the loads, and generates the optimal transient control strategy of each expected fault in each operating mode by taking the minimum comprehensive fitness as the optimization target.

[0036] The present application provides a transient control measure search method and device for a power system, wherein the method comprises the following steps: generating an optimal transient control strategy of each expected fault in each operating mode according to a plurality of expected faults and a plurality of operating modes of the power system, wherein the plurality of operating modes comprises a typical operating mode, a limit operating mode and a plurality of intermediate operating modes between the typical operating mode and the limit operating mode; obtaining a first stability control strength of each expected fault in each operating mode according to a preset stability control strength index, wherein the first stability control strength reflects the severity of the influence of the expected fault on the transient stability of the power system; determining the interval of the current operating mode according to the current load level of the system when an input fault occurs and the system load level corresponding to each operating mode, and determining a second stability control strength of the input fault in the current operating mode according to the first stability control strength and the interval, wherein the second stability control strength reflects the severity of the influence of the input fault on the transient stability of the power system; determining an approximate expected fault of the input fault according to the first stability control strength and the second stability control strength, and determining a transient control measure of the input fault according to an optimal transient control strategy of the approximate expected fault in a corresponding operating mode, wherein the difference between the first stability control strength and the second stability control strength of the approximate expected fault in a certain operating mode is not greater than a preset threshold.

[0037] Therefore, the present application has the following beneficial effects:

[0038] The operation mode of the present application includes a typical operation mode, several intermediate operation modes and an extreme operation mode, firstly, the optimal transient control strategy of each expected fault under each operation mode is generated according to a plurality of expected faults and a plurality of operation modes of the power system; then, the first stability control strength of each expected fault under each operation mode is calculated to reflect the influence degree of the expected fault on the transient stability of the system, and the second stability control strength of the input fault under the current operation mode is calculated to reflect the influence degree of the input fault on the transient stability of the system, the first and second stability control strengths consider the factors influencing the power flow, and can reflect the influence of the fault on the transient stability of the power system in real time; finally, the similar relationship between the input fault and a certain typical expected fault is obtained according to the first and second stability control strengths, so as to determine the approximate expected fault of the input fault, and the transient control measure of the input fault is obtained according to the optimal transient control strategy of the approximate expected fault under the corresponding operation mode, so that the corresponding transient control measure of the input fault can be quickly and accurately determined. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 The flowchart of the method embodiment one of the present application is shown in the figure;

[0040] Figure 2 The flowchart of the method embodiment two of the present application is shown in the figure;

[0041] Figure 3 The structure diagram of the device embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0042] The present application embodiment provides a transient control measure search method and device for a power system, so as to solve the technical problem that the existing transient control measure search method is difficult to balance high efficiency and high accuracy.

[0043] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the related drawings. The preferred embodiments of the present application are shown in the drawings. However, the present application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0045] With the increasing capacity of power system, the power grid develops to the super-high voltage transmission and cross-regional interconnection, and its requirements for safe and stable, flexible and efficient operation control are increasing. The most important problem in the development of power system is to maintain its stable operation, and enhancing the stability of power system has been a long-term and arduous task in the development of power system.

[0046] Transient stability control is an important aspect of interconnection system stability and control research, and is also an important line of defense for the stable operation of the power system. A large amount of transient stability analysis is required in power system planning, design, operation and other work, and the effect of various stability measures and the performance of stability control can be studied and investigated through transient stability analysis, which has great significance.

[0047] The second line of defense for the long-term safe and stable operation of China's power grid is to take necessary measures such as generator tripping and load shedding to ensure that the power grid can continue to operate stably in the event of a serious fault. The root cause of many extremely destructive power system stability accidents is generator angle instability, and transient control needs to provide sufficient damping for such angle oscillation and take certain control measures (such as generator tripping and load shedding) to stabilize the system to a new equilibrium state.

[0048] The existing transient control measure search method is difficult to balance high analysis speed and high accuracy, and the present application provides a transient control measure search method for a power system.

[0049] In a first aspect, referring to Figure 1 The present application provides an embodiment of a transient control measure search method for a power system, comprising:

[0050] S100: generating an optimal transient control strategy for each of the plurality of expected faults under each of the plurality of operating modes according to the plurality of expected faults and the plurality of operating modes, wherein the plurality of operating modes includes a typical operating mode, a limit operating mode, and a plurality of intermediate operating modes between the typical operating mode and the limit operating mode;

[0051] S200: obtaining a first stability control strength of each of the plurality of expected faults under each of the plurality of operating modes according to a preset stability control strength index, wherein the first stability control strength reflects the severity of the influence of the expected fault on the transient stability of the power system;

[0052] S300: determining the belonging interval of the current operating mode according to the current load level when the system occurs an input fault and the system load level corresponding to each of the plurality of operating modes, and determining a second stability control strength of the input fault under the current operating mode according to the first stability control strength and the belonging interval, wherein the second stability control strength reflects the severity of the influence of the input fault on the transient stability of the power system.

[0053] S400: determining an approximate expected fault of the input fault according to the first stability control strength and the second stability control strength, and determining a transient control measure of the input fault according to an optimal transient control strategy of the approximate expected fault in a corresponding operation mode, wherein a difference between the first stability control strength and the second stability control strength of the approximate expected fault in a certain operation mode is not greater than a preset threshold.

[0054] In the process of power system operation, common faults include single-phase short circuit, phase-to-phase short circuit, three-phase short circuit, transformer fault, generator set fault, bus fault, etc. With the gradual formation of UHV AC / DC large power grid, the risk of blocking fault, commutation failure fault and restart failure fault gradually increases, and the probability of single fault transforming into multiple faults and successive faults between regional power grids increases. In an embodiment of the present application, the expected faults that do not threaten the power system are excluded, and a plurality of expected faults that may cause instability of the power system are selected to form an expected fault set.

[0055] In some embodiments of the present application, based on the system load level, a plurality of intermediate operation modes [C1, C2,...C g ](g∈[1,t]) are established for the power system, wherein C1 represents the first intermediate operation mode, C g g represents the gth intermediate operation mode, and t represents the number of intermediate operation modes; the intermediate operation mode is an operation mode between the typical operation mode and the size limit operation mode, and finally the optimal transient control strategy Y gi .

[0056] It can be understood that the plurality of operation modes of the power system include: typical operation mode, limit operation mode and a plurality of intermediate operation modes. For each operation mode of the power system, there is a corresponding system load level.

[0057] Based on a certain operation mode of the power system, for example, based on the typical operation mode of the system, a certain amount of generator tripping amount and load shedding amount is selected for each expected fault in the expected fault set. When the power system is unstable, the relationship between the generator angular velocity and the power angle on the phase plane after fault removal is calculated according to the principle that the power angle cannot be abruptly changed before and after fault removal, and the minimum approximate generator tripping amount that stabilizes the power system is calculated. The power transmission section of the system is selected, and the proportion of generator tripping and load shedding is calculated through the relationship between power and voltage amplitude and voltage phase on the power transmission section, and finally the actual generator tripping amount and load shedding amount of the power system are obtained.

[0058] By using the above method, the control measures of each expected fault under any operating mode can be calculated, that is, the corresponding tripping parameters (including the number of trippable generator nodes and the trippable amount of each generator node) and the load shedding parameters (including the number of trippable load nodes and the trippable amount of each load node) of each expected fault and any operating mode are calculated.

[0059] In step S100, the optimal transient control strategy of each expected fault under each operating mode is generated according to a plurality of expected faults and a plurality of operating modes of the power system, and specifically can include:

[0060] According to the preset sensitivity index, the sensitivity of each expected fault to different control measures is calculated.

[0061] According to the electrical distance between the units and loads corresponding to different control measures, the sensitivity is clustered to generate a plurality of control measure clusters, and the tripping parameters and load shedding parameters of each stability control measure cluster under each operating mode are calculated.

[0062] According to the tripping parameters and load shedding parameters, the comprehensive fitness of each expected fault is calculated, and the optimal transient control strategy of each expected fault under each operating mode is generated with the minimum comprehensive fitness as the optimization target.

[0063] In order to measure the influence of stability control measures such as generator tripping and load shedding on the voltage stability of the power grid, the sensitivity of the voltage stability transient control measure is calculated according to the preset sensitivity index, which represents the sensitivity of the voltage of each bus to the amount of generator tripping and load shedding control measures.

[0064] For each expected fault i, the sensitivity [S ij |j=1,2...n] of different control measures j based on different units and loads is calculated according to formula (1):

[0065]

[0066] Wherein, S ij represents the sensitivity of the expected fault i to the control measure j, f ij (w) represents the difference in voltage or power angle stability level before and after the action of the control measure after the occurrence of the expected fault i; g ij (v) represents the change in node load.

[0067] It can be understood that in an embodiment of the present application, the preset sensitivity index is f ij (w) and g ij (v).

[0068] Based on the sensitivity, and considering the electrical distance between the units and loads corresponding to different control measures, the sensitivity [S ij|j = 1, 2...n] are clustered to generate a plurality of control measure clusters [C m |m = 1, 2...M], where M is the number of control measure clusters, and for each control measure cluster [C m ], the parameters of the control measures contained therein can be used to obtain the parameters of the control measures in each operating mode. Specifically, the parameters of the control measures can be: the number of generator nodes that can be cut off and the amount of each generator node that can be cut off, and the parameters of the control measures can be: the number of load nodes that can be cut off and the amount of each load node that can be cut off.

[0069] In an embodiment of the present application, the number of generator nodes that can be cut off and the amount of each generator node that can be cut off, and the number of load nodes that can be cut off and the amount of each load node that can be cut off can be determined by using similar methods for calculating the actual amount of generator nodes that can be cut off and the amount of load nodes that can be cut off when implementing corresponding control measures on the power system in a certain operating mode (such as a typical operating mode). The calculation method is the same for any operating mode, so the number of generator nodes that can be cut off and the amount of each generator node that can be cut off, and the number of load nodes that can be cut off and the amount of each load node that can be cut off in any operating mode can be obtained.

[0070] Based on the obtained number of generator nodes that can be cut off and the amount of each generator node that can be cut off, and the number of load nodes that can be cut off and the amount of each load node that can be cut off, the comprehensive fitness D i of the contingency i is calculated using formula (2) gi .

[0071]

[0072] where D i is the comprehensive fitness of the contingency i, N G is the number of generator nodes that can be cut off; N L is the number of load nodes that can be cut off; ΔP G,a is the amount of the a-th generator node that can be cut off; ΔP L,b is the amount of the b-th load node that can be cut off; α and β are weight coefficients, which are usually determined by the analytic hierarchy process; u a and u b are the control amounts of the amount of generator nodes that can be cut off and the amount of load nodes that can be cut off, respectively; in engineering, the amount of generator nodes that can be cut off is usually the amount of a whole generator that is cut off, so u a is a discrete integer; the amount of load nodes that can be cut off is usually cut off according to the voltage drop caused by the fault in a certain proportion, so u b is a continuous variable in [0, 1];

[0073] where the control amount should satisfy the following constraints:

[0074]

[0075] 0≤u b ≤1, b = 1, 2,..., N L

[0076] In the same way, the optimal transient control strategy of each expected fault under various operating modes can be generated.

[0077] In an embodiment of the present application, when defining the first stability control strength, first, the severity of the expected fault is evaluated according to the influence of the expected fault on transient stability, the first stability control strength corresponding to the transient stability fault severity is calculated according to the preset stability control strength index, and a nonlinear variation relationship K cj = i (P Gen , P Load , P Interface ) of the first stability control strength of each expected fault under different operating modes is established; wherein P Gen represents the active power of the key generator node, P Load represents the active power of the key load node, and P Interface represents the active power of the key section.

[0078] It should be noted that the key section is a set of domain main lines that bear power interaction between power system regions, and the system will be divided into two independent subsystems if such lines are disconnected; the key generator node and the key load node refer to nodes that are representative and have a significant impact on the power system.

[0079] It can be understood that in an embodiment of the present application, the preset stability control strength index is P Gen , P Load and P Interface .

[0080] The definition of the nonlinear variation relationship K cj of the first stability control strength takes into account the flow factors that affect transient stability, and the first stability control strength is expressed in numerical form through weighting, which is convenient for explaining the real-time change of the first stability control strength and determining the similarity between the input fault and a typical expected fault, thereby quickly determining the transient control measures.

[0081] In step S300, the interval to which the current operating mode belongs is determined according to the current load level when the system has an input fault, and the system load level corresponding to each operating mode, and the second stability control strength of the input fault under the current operating mode is determined according to the first stability control strength and the interval.

[0082] For any operating mode of the power system, based on the system load level and power flow at key sections, the interval to which the current operating mode belongs is determined by comparing it with the load level information of several other operating modes. i C j Based on the first stabilization level and the corresponding interval, the second stabilization level for a certain input fault under the current operating mode is determined using the cubic spline interpolation method.

[0083] Specifically, let the interpolation interval be [C]. a C b There are interpolation nodes on [C]. a For the minimum interpolation boundary, C b For the maximum interpolation boundary, C1, C2, C n For interpolation nodes, C a =C1<C2<…<C n =C b C1, C2, ..., C n The corresponding first stabilization forces are K1, K2, ..., K n The function S(C) satisfies S(C) j ) = K j (j=1,2,…,n),S(C) in [C j C j+1 ] (j=1,2,…,n-1) are all polynomials of degree no higher than 3, and S(C) is in [C a C b It has a second continuous derivative. The cubic spline function S(C) is solved using the second derivative as a linear function.

[0084] In step S400, an approximate expected fault of the input fault is determined based on the first stabilization strength and the second stabilization strength. Transient control measures of the input fault are determined based on the optimal transient control strategy of the approximate expected fault under the corresponding operating mode. The difference between the first stabilization strength and the second stabilization strength of the approximate expected fault under a certain operating mode is not greater than a preset threshold.

[0085] After the second stability control strength of the input fault in the current operation mode is determined according to the above method, the transient control measure corresponding to the current input fault is further determined. According to the second stability control strength, an approximate expected fault close to the second stability control strength in a certain fixed operation mode is found. Specifically, the second stability control strength is compared with the first stability control strength, and the first stability control strength close to the second stability control strength (i.e. the difference between the first stability control strength and the second stability control strength is not greater than a preset threshold) is found. According to the first stability control strength, the corresponding expected fault and operation mode are found, and the expected fault is taken as the approximate expected fault. Then, the optimal transient control strategy of the approximate expected fault in the corresponding operation mode (which has been solved in step S100) is found, and the optimal transient control strategy is taken as the transient control measure of the input fault in the current operation mode.

[0086] By analogy, the transient control measure of the input fault can be quickly searched by virtue of the second stability control strength corresponding to the input fault and the first stability control strength of the power system.

[0087] The power system transient control measure searching method provided in the embodiment includes the following steps.

[0088] In the second aspect, referring to Figure 2 The present application further provides another embodiment of a power system transient control measure searching method, which includes the following steps.

[0089] (1) Establish an expected fault set. Based on a typical operation mode, for each fault in the expected fault set, a certain amount of generator tripping and load shedding is selected.

[0090] (2) Define a sensitivity index and calculate a sensitivity index set based on different generator units and loads to generate control measures.

[0091] (3) Generate a plurality of control measure clusters. For each control measure cluster, the capacity of the corresponding generator tripping and load shedding is set.

[0092] (4) define the comprehensive fitness index, the minimum objective of the comprehensive fitness index of the predicted fault is optimized;

[0093] (5) establish a number of intermediate operating modes, calculate the transient control strategy of each operating mode and each predicted fault;

[0094] (6) define the stability control strength coefficient, and establish the nonlinear variation relationship of the stability control strength coefficient of each predicted fault under different operating modes;

[0095] (7) determine the control measures, determine the interval to which the current operating mode belongs, determine the stability control strength coefficient corresponding to the input fault in the operating mode by using the interpolation method, and further determine the transient control measures of the input fault.

[0096] Thirdly, please refer to Figure 3 The application further provides an embodiment of a transient control measure searching device of a power system, which comprises:

[0097] An optimal transient control strategy determination module 11 is configured to generate optimal transient control strategies of each predicted fault under each operating mode according to a plurality of predicted faults and a plurality of operating modes of the power system, wherein the plurality of operating modes comprises a typical operating mode, a limit operating mode, and a plurality of intermediate operating modes between the typical operating mode and the limit operating mode;

[0098] A first stability control strength calculation module 22 is configured to obtain first stability control strengths of each predicted fault under each operating mode according to a preset stability control strength index, wherein the first stability control strength reflects the severity of the influence of the predicted fault on the transient stability of the power system;

[0099] A second stability control strength determination module 33 is configured to determine an interval to which a current operating mode belongs according to a current load level when the system has an input fault and system load levels corresponding to each operating mode, and determine a second stability control strength of the input fault under the current operating mode according to the first stability control strength and the interval, wherein the second stability control strength reflects the severity of the influence of the input fault on the transient stability of the power system;

[0100] A transient control measure determination module 44 is configured to determine an approximate predicted fault of the input fault according to the first stability control strength and the second stability control strength, and determine a transient control measure of the input fault according to the optimal transient control strategy of the approximate predicted fault under the corresponding operating mode, wherein the difference between the first stability control strength and the second stability control strength of the approximate predicted fault under a certain operating mode is not greater than a preset threshold.

[0101] In the preferred implementation, the optimal transient control strategy determination module 11 generates the optimal transient control strategy for each of the envisioned faults in each of the operating modes according to a plurality of envisioned faults and a plurality of operating modes of the power system, which includes:

[0102] The optimal transient control strategy determination module calculates the sensitivity of each of the envisioned faults to different control measures according to a preset sensitivity index;

[0103] The optimal transient control strategy determination module generates a plurality of control measure clusters by clustering the sensitivity according to the electrical distance between the units and loads corresponding to different control measures, and calculates the unit tripping parameters and load shedding parameters of each of the control measure clusters in each of the operating modes;

[0104] The optimal transient control strategy determination module calculates the comprehensive fitness of each of the envisioned faults according to the unit tripping parameters and load shedding parameters, and generates the optimal transient control strategy for each of the envisioned faults in each of the operating modes with the minimum comprehensive fitness as the optimization target.

[0105] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the system, device and unit described above can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0106] In the embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of units is only a logical function division, and there can be another division manner in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0107] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e. they can be located in one place, or distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments.

[0108] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware, or in the form of a software functional unit.

[0109] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application or the entire or part of the technical solutions that essentially contribute to the prior art can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0110] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of searching for a transient control measure of a power system, characterized by, The method comprises the following steps: generating optimal transient control strategies of each of the plurality of contingency faults under each of the plurality of operating modes according to the plurality of contingency faults and the plurality of operating modes, wherein the plurality of operating modes comprises a typical operating mode, a limit operating mode and a plurality of intermediate operating modes between the typical operating mode and the limit operating mode; obtaining first stability control strengths of each of the plurality of contingency faults under each of the plurality of operating modes according to a preset stability control strength index, wherein the first stability control strengths reflect the severity of the influence of the contingency faults on the transient stability of the power system; determining a belonging interval of a current operating mode according to a current load level when an input fault occurs in the system and system load levels corresponding to each of the plurality of operating modes, determining second stability control strengths of the input fault under the current operating mode according to the first stability control strengths and the belonging interval, wherein the second stability control strengths reflect the severity of the influence of the input fault on the transient stability of the power system; determining an approximate contingency fault of the input fault according to the first stability control strengths and the second stability control strengths, and determining a transient control measure of the input fault according to the optimal transient control strategy of the approximate contingency fault under the corresponding operating mode, wherein the difference between the first stability control strength and the second stability control strength of the approximate contingency fault under a certain operating mode is not greater than a preset threshold.

2. The transient control action search method of a power system according to claim 1, characterized by, The method of generating optimal transient control strategies of each of the plurality of contingency faults under each of the plurality of operating modes according to the plurality of contingency faults and the plurality of operating modes comprises: calculating the sensitivity of each of the plurality of contingency faults to different control measures according to a preset sensitivity index; generating a plurality of control measure clusters by clustering the sensitivity according to the electrical distance between the corresponding units and loads of different control measures, and calculating the generator tripping parameters and load shedding parameters of each of the control measure clusters under each of the operating modes; calculating the comprehensive fitness of each of the plurality of contingency faults according to the generator tripping parameters and load shedding parameters, and generating the optimal transient control strategy of each of the plurality of contingency faults under each of the operating modes with the minimum comprehensive fitness as the optimization objective.

3. The transient control action search method of a power system according to claim 2, characterized by, The method of calculating the sensitivity of each of the plurality of contingency faults to different control measures according to a preset sensitivity index comprises: For each of the anticipated failures i, the sensitivity of the control measures j to the different units is calculated based on The sensitivity of different control measures j to produce different loads based on different units is calculated; where S ij represents the sensitivity of the expected fault i to the control measure j, f ij (w) represents the difference in voltage or power angle stability level before and after the control measure acts after the occurrence of the expected fault i; g ij (v) represents the amount of change in the node load.

4. The transient control action search method of a power system according to claim 2, characterized by, The generator tripping parameters are the number of generator nodes that can be tripped and the amount of each generator node that can be tripped.

5. The method of claim 2, wherein, The load shedding parameters are the number of load nodes that can be tripped and the amount of each load node that can be tripped.

6. The method of claim 2, wherein, The comprehensive fitness is: where D i is the comprehensive fitness of the contingency i, N G is the number of generators that can be switched off; N L is the number of loads that can be switched off; ΔP G,a is the amount of generators that can be switched off at bus a; ΔP L,b is the amount of loads that can be switched off at bus b; a and β are weight coefficients; u a and u b are the control variables for the amount of generators and loads switched off, respectively; u a takes discrete integer values, u a = 1 means that bus a is switched off, u a = 0 means that bus a is not switched off, a = 1, 2,..., N G ; u b is a continuous variable in [0, 1], b = 1, 2,..., N L .

7. The transient control action search method of a power system according to claim 1, wherein, The method of determining the second stability control strengths of the input fault under the current operating mode according to the first stability control strengths and the belonging interval comprises: determining the second stability control strengths of the input fault under the current operating mode by using a cubic spline interpolation method according to the first stability control strengths and the belonging interval.

8. The method of claim 1, wherein, The method of determining the transient control measure of the input fault according to the optimal transient control strategy of the approximate contingency fault under the corresponding operating mode comprises: taking the optimal transient control strategy of the approximate contingency fault under the corresponding operating mode as the transient control measure of the input fault.

9. A device for searching transient control measures in a power system, characterized in that, The method comprises the following steps: The optimal transient control strategy determination module is configured to generate optimal transient control strategies of each of the plurality of contingency faults in each of a plurality of operating modes of the power system, the plurality of operating modes including a typical operating mode, a limit operating mode, and a plurality of intermediate operating modes between the typical operating mode and the limit operating mode; The first stability control strength calculation module is configured to obtain a first stability control strength of each of the plurality of contingency faults in each of the plurality of operating modes according to a preset stability control strength index, the first stability control strength reflecting a severity of an influence of the contingency fault on transient stability of the power system; The second stability control strength determination module is configured to determine a corresponding interval of a current operating mode according to a current load level of the power system when an input fault occurs and a system load level corresponding to each of the plurality of operating modes, and determine a second stability control strength of the input fault in the current operating mode according to the first stability control strength and the corresponding interval, the second stability control strength reflecting the severity of the influence of the input fault on the transient stability of the power system; The transient control measure determination module is configured to determine an approximate contingency fault of the input fault according to the first stability control strength and the second stability control strength, and determine a transient control measure of the input fault according to an optimal transient control strategy of the approximate contingency fault in a corresponding operating mode, the difference between the first stability control strength and the second stability control strength of the approximate contingency fault in the operating mode being not greater than a preset threshold.

10. The transient control action search apparatus of an electric power system according to claim 9, wherein, The optimal transient control strategy determination module is configured to generate optimal transient control strategies of each of the plurality of contingency faults in each of a plurality of operating modes of the power system, the plurality of operating modes including a typical operating mode, a limit operating mode, and a plurality of intermediate operating modes between the typical operating mode and the limit operating mode; The optimal transient control strategy determination module is configured to calculate a sensitivity of each of the plurality of contingency faults to different control measures according to a preset sensitivity index; A plurality of control measure clusters are generated by clustering the sensitivity according to electrical distances between corresponding units and loads of the different control measures, and a generator tripping parameter and a load shedding parameter of each of the control measure clusters in each of the operating modes are calculated; A comprehensive fitness of each of the contingency faults is calculated according to the generator tripping parameter and the load shedding parameter, and an optimal transient control strategy of each of the contingency faults in each of the operating modes is generated with a minimum comprehensive fitness as an optimization target.

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