Static safety assessment method and device for flexible direct delivery system of clean energy base

Abstract

The invention provides a static safety assessment method and device for a flexible direct output system of a clean energy base, and the method comprises the steps: obtaining the number of power flow sections of a power grid research range where the flexible direct output system of the clean energy base is located, the number of power transmission channels of each power flow section, and the number of all branch elements; on the basis of the existing static safety analysis method, the active power of each power transmission channel of a power flow section is regarded as a vector, and a quantitative index capable of visually describing power flow redistribution is given by means of a calculated vector included angle between a ground state power flow mode and a fault N-1 mode, so that the operation state of a ground branch element is quickly judged, and the power flow redistribution can be visually described. And moreover, the calculation amount is small, the application is convenient, and a qualitative leap is brought to a traditional static safety analysis method.

Description

Technical Field

[0001] The present invention relates to the field of power safety assessment, and more particularly, to a static safety assessment method and device for a flexible DC transmission system of a clean energy base. Background Art

[0002] With the continuous construction of large-capacity renewable energy bases, a new scenario has emerged where the power output of a new energy base is first collected through the local AC grid and then the collected electric energy is sent out through a UHV flexible DC system, that is, a flexible DC transmission system for a clean energy base. Such a power system with this characteristic appears for the first time. Therefore, there is a lack of research on the static safety analysis of the power system in this scenario. The existing general static safety analysis methods can expose the weak links in the system through the occurrence of contingency events, but lack an overall intuitive and fast-solving index to describe the severity after the occurrence of contingency events.

[0003] Static safety analysis is an analysis method often used in power grid planning and operation, and is used to judge whether the system will have overload or voltage violation after the occurrence of contingency events. The commonly used contingency events follow the "N-1 principle" (single-fault safety inspection rule), causing single faults in components such as AC lines in the system. Specifically, the fault N-1 mode means that any component (such as a line, generator, transformer, DC monopole, etc.) in the power system under normal operation mode is disconnected without a fault or due to a fault, and the power system should be able to maintain stable operation and normal power supply, and other components should not be overloaded, and the voltage and frequency should be within the allowable range. One of the disadvantages of the existing static safety analysis technology is that it is necessary to analyze the operating states of all branch components in the power flow of all fault N-1 modes within the power grid research scope for the base state power flow and the power grid, including overload, overcurrent, etc., and the workload of this task is very large. Summary of the Invention

[0004] In order to solve the technical problem that when the existing static safety analysis method adopts the fault N-1 mode, it is necessary to analyze the states of all branch components within the power grid research scope, resulting in a large analysis workload, the present invention provides a static safety assessment method and device for a flexible DC transmission system of a clean energy base.

[0005] According to one aspect of the present invention, the present invention provides a static safety assessment method for a flexible DC transmission system of a clean energy base, including:

[0006] Obtaining the number I of power flow sections in the power grid research scope of the flexible DC transmission system of the clean energy base, the number of transmission channels in each power flow section, and the number of branch components in each transmission channel;

[0007] Performing power flow calculation based on the configured base state power flow data to determine the base state power flow that satisfies the normal operation of the power grid;

[0008] Disconnect all branch elements within the power grid research scope in sequence according to the fault N - 1 mode, and perform N power flow calculations to obtain the results of N power flow calculations.

[0009] Determine the vector P of each power flow section according to the base - state power flow and the number of transmission channels in each power flow section 0_i , and determine the vector P of each power flow section according to the result of the nth power flow calculation and the number of transmission channels in each power flow section n_i , where 1 ≤ i ≤ I, 1 ≤ n ≤ N;

[0010] According to the vector P n_i and P 0_i Calculate the vector included angle between the power flow of each power flow section under the nth fault N - 1 mode and the base - state power flow.

[0011] Respond to the comparison result that all the vector included angles are less than the set included - angle threshold, and determine that the base - state power flow meets the static security analysis requirements of the power grid research scope.

[0012] Optionally, the performing power flow calculations based on the configured base - state power flow data to determine the base - state power flow that meets the normal operation of the power grid includes:

[0013] Perform power flow calculations based on the configured base - state power flow data to obtain the results of base - state power flow calculations;

[0014] According to the results of the base - state power flow calculations, determine the working states of the branch elements of each transmission channel in each power flow section, where the working states include normal state and abnormal state;

[0015] When all branch elements within the power grid research scope are in the normal state, determine that the base - state power flow obtained according to the configured base - state power flow data meets the normal operation of the power grid; otherwise, adjust the configured base - state power flow data and perform power flow calculations again until all branch elements within the power grid research scope are in the normal state.

[0016] Optionally, the determining the vector P of each power flow section according to the base - state power flow and the number of transmission channels in each power flow section 0_i , and determining the vector P of each power flow section according to the result of the nth power flow calculation and the number of transmission channels in each power flow section n_i , and their expressions are respectively:

[0017]

[0018]

[0019] In the formula, P 0_i and Pn_i are the vectors of the power flow of the i-th power flow section under the base-state power flow and the fault N-1 condition, where 1 ≤ j ≤ J i , J i is the number of transmission channels in the i-th power flow section; P 0_ij and P n_ij are respectively the sum of the active power of all branch circuits of the j-th transmission channel in the power flow of the i-th power flow section under the base-state power flow and the fault N-1 condition.

[0020] Optionally, calculating the vector angle between the power flow of each power flow section under the n-th fault N-1 condition and the base-state power flow according to the vectors P 0_i and P n_i , and its calculation formula is:

[0021]

[0022] In the formula, θ n_i is the vector angle between the power flow of the i-th power flow section under the n-th fault N-1 condition and the base-state power flow.

[0023] Optionally, the method further includes:

[0024] When the comparison result is that there is at least one vector angle not less than the set angle threshold, checking all branch circuit components of the power flow section where the at least one vector angle is located. Only when all branch circuit components are in the normal state, it is determined that the base-state power flow meets the static security analysis requirements of the power grid research scope; otherwise, the base-state power flow does not meet the static security analysis requirements of the power grid research scope.

[0025] According to another aspect of the present invention, the present invention provides a static security assessment device for a flexible DC transmission system for a clean energy base, and the device includes:

[0026] A data acquisition module, configured to acquire the number I of power flow sections in the power grid research scope of the flexible DC transmission system for the clean energy base, the number of transmission channels of each power flow section, and the number of branch circuit components of each transmission channel;

[0027] A first calculation module, configured to perform power flow calculation according to the configured base-state power flow data to determine the base-state power flow that meets the normal operation of the power grid;

[0028] A second calculation module, configured to disconnect all branch circuit components of the power grid research scope in sequence according to the fault N-1 condition, and perform N power flow calculations to obtain N power flow calculation results;

[0029] A third calculation module, configured to determine the vector P of each power flow section according to the base-state power flow and the number of transmission channels of each power flow section 0_i, and determining the vector P of each power flow section according to the nth power flow calculation result and the number of transmission channels of each power flow section n_i , where 1 ≤ i ≤ I and 1 ≤ n ≤ N;

[0030] The fourth calculation module is used to calculate the vector angle between the power flow of each power flow section in the nth fault N-1 mode and the base state power flow according to the vector P n_i and P 0_i ;

[0031] The result output module is used to determine that the base state power flow meets the static security analysis requirements of the power grid research scope in response to the comparison result that all the vector angles are less than the set angle threshold.

[0032] Optionally, the first calculation module performs a power flow calculation according to the configured base state power flow data to determine the base state power flow that meets the normal operation of the power grid, including:

[0033] Performing a power flow calculation according to the configured base state power flow data to obtain the base state power flow calculation result;

[0034] Determining the working state of the branch components of each transmission channel in each power flow section according to the base state power flow calculation result, where the working state includes a normal state and an abnormal state;

[0035] When all the branch components in the power grid research scope are in the normal state, it is determined that the base state power flow obtained according to the configured base state power flow data meets the normal operation of the power grid; otherwise, the configured base state power flow data is adjusted and the power flow calculation is performed again until all the branch components in the power grid research scope are in the normal state.

[0036] Optionally, the third calculation module determines the vector P of each power flow section according to the base state power flow and the number of transmission channels of each power flow section 0_i , and determining the vector P of each power flow section according to the nth power flow calculation result and the number of transmission channels of each power flow section n_i , and their expressions are respectively:

[0037]

[0038]

[0039] In the formula, P 0_i and P n_i are respectively the vectors of the power flow of the ith power flow section in the base state power flow and the fault N-1 mode, 1 ≤ j ≤ J i , J i is the number of transmission channels in the ith power flow section; P 0_ij and P n_ijThey are respectively the sum of the active powers of all branches of the j-th transmission channel in the power flow of the i-th power flow section under the base-state power flow and the fault N-1 mode.

[0040] Optionally, the fourth calculation module calculates, based on the vectors P 0_i and P n_i the vector angle between the power flow of each power flow section under the n-th fault N-1 mode and the base-state power flow. The calculation formula is as follows:

[0041]

[0042] In the formula, θ n_i is the vector angle between the power flow of the i-th power flow section under the n-th fault N-1 mode and the base-state power flow.

[0043] Optionally, the result output module is further configured to:

[0044] When the comparison result is that there is at least one vector angle not less than the set angle threshold, check all branch components of the power flow section where the at least one vector angle is located. Only when all branch components are in a normal state, it is determined that the base-state power flow meets the static security analysis requirements of the power grid research scope; otherwise, the base-state power flow does not meet the static security analysis requirements of the power grid research scope.

[0045] According to another aspect of the present invention, there is provided a computer-readable storage medium storing a computer program for executing the method described in any of the above aspects of the present invention.

[0046] According to another aspect of the present invention, there is provided an electronic device including: a processor; a memory for storing executable instructions of the processor; the processor is configured to read the executable instructions from the memory and execute the instructions to implement the method described in any of the above aspects of the present invention.

[0047] Static security assessment method and device for a clean energy base transmitted through a flexible DC transmission system according to the present invention. Among them, the method includes: obtaining the number I of power flow sections in the research scope of the power grid where the clean energy base is transmitted through the flexible DC transmission system, the number of transmission channels in each power flow section, and the number of branch elements in each transmission channel; performing power flow calculation based on the configured base state power flow data to determine the base state power flow that satisfies the normal operation of the power grid; disconnecting all branch elements in the research scope of the power grid in sequence according to the fault N-1 mode, and performing N power flow calculations to obtain N power flow calculation results; determining the vector P0_i of each power flow section according to the base state power flow and the number of transmission channels in each power flow section, and determining the vector Pn_i of each power flow section according to the nth power flow calculation result and the number of transmission channels in each power flow section; calculating the vector included angle between the power flow and the base state power flow of each power flow section in the nth fault N-1 mode according to the vectors Pn_i and P0_i; in response to the comparison result that all the included angles are less than the set included angle threshold, determining that the base state power flow meets the static security analysis requirements of the research scope of the power grid. Based on the existing static security analysis method, the method and device of the present invention regard the active power of each transmission channel in the power flow section as a vector, and with the help of the included angle between the base state power flow mode and the fault N-1 mode, give a quantitative index that can intuitively describe the redistribution of power flow, and has a small calculation amount and is convenient to apply, bringing a qualitative leap to the traditional static security analysis method. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The exemplary embodiments of the present invention can be more fully understood by referring to the following drawings:

[0049] Figure 1 It is a flowchart of the static security assessment method for a clean energy base transmitted through a flexible DC transmission system according to a preferred embodiment of the present invention;

[0050] Figure 2 It is a geographical connection diagram of a clean energy base transmitted through a flexible DC transmission system according to a preferred embodiment of the present invention;

[0051] Figure 3 It is a schematic diagram of the power flow direction of a clean energy base transmitted through a flexible DC transmission system according to a preferred embodiment of the present invention;

[0052] Figure 4 It is a schematic structural diagram of the static security assessment device for a clean energy base transmitted through a flexible DC transmission system according to a preferred embodiment of the present invention;

[0053] Figure 5 It is a schematic structural diagram of an electronic device according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] Reference is now made to the accompanying drawings to describe exemplary embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely, and to fully convey the scope of the present invention to those skilled in the art. The terms in the exemplary embodiments shown in the drawings are not intended to limit the present invention. In the drawings, the same units / components are denoted by the same reference numerals.

[0055] Unless otherwise specified, the terms used herein (including technical terms) have the ordinary meaning understood by those skilled in the art. In addition, it can be understood that the terms defined in the commonly used dictionary should be understood to have a meaning consistent with the context of their related fields, and should not be understood as idealized or overly formal meanings.

[0056] Exemplary method

[0057] Figure 1 is a flowchart of a static security assessment method for a flexible DC transmission system for a clean energy base according to a preferred embodiment of the present invention. As Figure 1 shown, the static security assessment method for the flexible DC transmission system for the clean energy base described in this preferred embodiment starts from step 101.

[0058] In step 101, obtain the number I of power flow sections in the research scope of the power grid where the flexible DC transmission system for the clean energy base is located, the number of transmission channels in each power flow section, and the number of branch elements in each transmission channel.

[0059] The flexible DC transmission system for the clean energy base described in this preferred embodiment refers to a new scenario in which the output of the clean energy base is first collected through the local AC power grid and then the collected electric energy is sent out through the UHV flexible DC system. Figure 2 is a geographical connection diagram of the flexible DC transmission system for the clean energy base according to a preferred embodiment of the present invention. As Figure 2 shown, in the research scope of the power grid, the main power flow direction is that the active power of the AC system flows out of subnet 2 and is injected into subnet 1. In addition to this, there is another power flow direction, which is to collect power from the clean energy base and inject it into the rectifier station of the flexible DC project. This power flow direction can be regarded as almost orthogonal to the main power flow direction in the AC system, that is, 90°. Among them, buses 4, 10, 11 and rectifier station 1 are all connected to the clean energy base, and the active power collected by the above clean energy base is distributed between rectifier stations 1 and 2 according to the converter station capacity.

[0060] For Figure 2For the transmission system shown, when determining the power grid research scope, the clean energy base and the flexible DC must be included in the research scope; in addition, when extending to the power flow direction of the AC power grid, the AC power grid components adjacent to the clean energy base must be included. When extending from the clean energy base to the local AC power grid, the power flow section before the clean energy base is built can be observed. After crossing the power flow section, extending one more level of components (AC line or transformer) is the research scope of the power grid.

[0061] In the scenario of the clean energy base transmitting power through the flexible DC transmission system, there are two types of power flow sections: one is the power flow section where the output of the clean energy base converges to the flexible DC converter station, and the other is the power flow section that originally existed in the AC power grid. The number of the first type of power flow section is related to the number of converter stations. If there is only one converter station, the number of this type of power flow section is 1; if there are two converter stations, the number of power flow sections is 2. Figure 2 There are two converter stations, both of which converge the power of the clean energy base, so there are 2 such power flow sections. The number of the second type of power flow section is determined by the characteristics of the AC power grid during operation. According to the jurisdiction scope of the power grid equipment and combined with the power exchange situation between regions, including the magnitude and direction, it is determined. Therefore, from Figure 2 It can also be seen that the power grid research scope where the clean energy base and the flexible DC transmission system are located is divided into 4 power flow sections, that is, power flow section 1 to power flow section 4.

[0062] After determining the research scope and power flow sections of the power grid where the transmission system is located, it is also necessary to determine the transmission channels of each power flow section and the branch components of the transmission channels. The branch components include AC lines, transformers, etc.

[0063] Figure 3 It is a schematic diagram of the power flow direction of the clean energy base transmitting power through the flexible DC transmission system according to the preferred embodiment of the present invention. After adding the flow direction of the supplementary active power of the clean energy base transmitting power through the flexible DC transmission system in Figure 2 , it can be seen more clearly that the power flow direction between subnet 2 and subnet 1 is from left to right, while the power flow direction from bus 10, bus 4 to rectifier station 1 and rectifier station 2 is a longitudinal power flow direction, and the two are in an orthogonal state. Further, from Figure 3 It can be clearly seen that without considering the power flow mode, power flow section 1 includes 2 transmission channels, and the active power of all branches of each transmission channel is P 11 and P 12 , power flow section 2 also includes 2 transmission channels, and the active power of all branches of each transmission channel is P 21 and P 22 , power flow section 3 includes 3 transmission channels, and the active power of all branches of each transmission channel is P 31 、P 32 and P33 In addition, the tidal current section 4 also includes three power transmission channels, and the active power of all branches of each power transmission channel is P 41 , P 42 and P 43 . It should be noted that when the power transmission channel consists of double-circuit lines or multi-circuit lines, the active power of the same power transmission channel is the sum of the active powers of the double-circuit lines or multi-circuit lines of the power transmission channel.

[0064] In step 102, power flow calculation is performed based on the configured base-state power flow data to determine the base-state power flow that satisfies the normal operation of the power grid.

[0065] Preferably, the performing power flow calculation based on the configured base-state power flow data to determine the base-state power flow that satisfies the normal operation of the power grid includes:

[0066] Performing power flow calculation based on the configured base-state power flow data to obtain the base-state power flow calculation result;

[0067] Based on the base-state power flow calculation result, determining the working state of the branch components of each power transmission channel in each tidal current section, where the working state includes a normal state and an abnormal state;

[0068] When all the branch components within the power grid research scope are in the normal state, it is determined that the base-state power flow obtained based on the configured base-state power flow data satisfies the normal operation of the power grid; otherwise, the configured base-state power flow data is adjusted and power flow calculation is performed again until all the branch components within the power grid research scope are in the normal state.

[0069] In this preferred embodiment, for the base-state power flow result obtained by performing power flow calculation based on the configured base-state power flow data, it is necessary to check whether there is an overload phenomenon in the branch components of the power grid. For example, whether the current flowing through the AC line exceeds the rated current of the line; whether the power transmitted by the transformer exceeds the rated capacity, etc., and whether the voltage results of each bus within the power grid are all within the allowable range. If there are phenomena such as overload of the above branch components and voltage deviation from the normal level / beyond the allowable range of the equipment, then the base-state power flow data needs to be adjusted. The adjustment measures include adjusting the active / reactive state or output of the generator, adjusting the tap ratio of the transformer, putting into or withdrawing the shunt capacitor reactor, etc., until the base-state power flow result satisfies that any branch component is in the normal state.

[0070] In step 103, all the branch components within the power grid research scope are disconnected in sequence according to the fault N-1 mode, and N power flow calculations are performed to obtain N power flow calculation results.

[0071] In step 104, according to the base-state power flow and the number of power transmission channels in each tidal current section, determine the vector P of each tidal current section 0_i, and determining the vector \(P\) of each power flow section according to the \(n\)th power flow calculation result and the number of transmission channels of each power flow section n_i , where \(1\leq i\leq I\) and \(1\leq n\leq N\).

[0072] Preferably, determining the vector \(P\) of each power flow section according to the base-state power flow and the number of transmission channels of each power flow section 0_i , and determining the vector \(P\) of each power flow section according to the \(n\)th power flow calculation result and the number of transmission channels of each power flow section n_i , and their expressions are respectively:

[0073]

[0074]

[0075] In the formula, \(P\) 0_i and \(P\) n_i are respectively the vectors of the power flow of the \(i\)th power flow section under the base-state power flow and the power flow in the fault N-1 mode, where \(1\leq j\leq J\) i , and \(J\) i is the number of transmission channels in the \(i\)th power flow section; \(P\) 0_ij and \(P\) n_ij are respectively the sum of the active powers of all branches of the \(j\)th transmission channel in the power flow of the \(i\)th power flow section under the base-state power flow and the power flow in the fault N-1 mode.

[0076] After determining that the base-state power flow mode meets the requirements of static security analysis, power flow calculations are performed on the N branch elements within the scope of power grid research according to the fault N-1 mode. Specifically, based on the base-state power flow data, 1 to N power flow jobs are copied and set as the fault N-1 modes of the 1st to Nth branch elements respectively, that is, in the data of the power flow jobs, this branch element is set to the invalid state for power flow calculation. When the element N-1 within the scope of power grid research is disconnected, record the active power of the transmission channels of each power flow section under the base-state power flow mode and all fault N-1 modes according to the power flow calculation results. Among them, the active power of each transmission channel is the sum of the active powers of all branches within this channel. On this basis, the vector of each power flow section can be obtained.

[0077] In step 105, calculate the vector angle between the power flow of each power flow section in the \(n\)th fault N-1 mode and the base-state power flow according to the vectors \(P\) n_i and \(P\) 0_i .

[0078] Preferably, calculating the vector angle between the power flow of each power flow section in the \(n\)th fault N-1 mode and the base-state power flow according to the vectors \(P\) 0_i and \(P\) n_i , and its calculation formula is:

[0079]

[0080] where θ n_i is the vector included angle between the power flow of the i-th power flow section in the n-th fault N-1 mode and the base state power flow.

[0081] The vector included angle is a measure of the vector distance. In data analysis and machine learning, the cosine similarity of the vector included angle is commonly used to measure the similarity between different data. It is occasionally used in other industries. However, this index and method have not been applied in power system analysis for the time being. In the static security analysis of power systems, the vector included angle index can be used to measure the deviation degree between the mode after a contingency and the original mode. The difference from the most commonly used index is that a cosine value close to 1.0 indicates similarity; while in the technology of the present invention, the focus is on the deviation magnitude, so instead of using the cosine value, the angle value is directly used.

[0082] In step 106, in response to the comparison result that all the vector included angles are less than the set included angle threshold, it is determined that the base state power flow meets the static security analysis requirements of the power grid research scope.

[0083] Preferably, the method further includes:

[0084] When the comparison result is that there is at least one vector included angle not less than the set included angle threshold, all branch elements of the power flow section where the at least one vector included angle is located are checked. Only when all branch elements are in a normal state, it is determined that the base state power flow meets the static security analysis requirements of the power grid research scope; otherwise, the base state power flow does not meet the static security analysis requirements of the power grid research scope.

[0085] In this preferred embodiment, the included angle threshold is set to 10°. When all the vector included angles in all the fault N-1 modes are less than 10°, it is determined that the base state power flow data meets the requirements of the power grid static security analysis. Otherwise, when in any one of the fault N-1 modes, the value of any one vector included angle is greater than 10°, it is determined that the branch elements in the power flow section corresponding to the vector included angle need to be verified whether their operating states are abnormal. If it is verified that the branch elements in the power flow section corresponding to the vector included angle are overloaded or in other abnormal states, the base state power flow data needs to be readjusted, and the method of the present invention is performed again to determine whether all the vector included angles in all the fault N-1 modes are less than 10° until finally the base state power flow data meets the requirements of the power grid static security analysis.

[0086] After obtaining the number of power flow sections within the research scope of its own power grid, the number of transmission channels for each power flow section, and the number of all branch elements through the flexible DC transmission system, the clean energy base in this preferred embodiment regards the active power of each transmission channel in the power flow section as a vector, and gives a quantitative index that can intuitively describe the redistribution of power flow by means of the vector angle between the calculated base state power flow mode and the fault N-1 mode. Thus, it can quickly judge the operating state of the branch elements, with small computational effort and convenient application, bringing a qualitative leap to the traditional static security analysis method.

[0087] Exemplary device

[0088] Figure 4 FIG. is a schematic structural diagram of a static security assessment device for a clean energy base through a flexible DC transmission system according to a preferred embodiment of the present invention. As Figure 4 shown, the static security assessment device 400 for the clean energy base through the flexible DC transmission system in this preferred embodiment includes:

[0089] A data acquisition module 401, configured to acquire the number of power flow sections I within the research scope of the power grid where the clean energy base is located through the flexible DC transmission system, the number of transmission channels for each power flow section, and the number of branch elements for each transmission channel;

[0090] A first calculation module 402, configured to perform power flow calculation according to the configured base state power flow data to determine the base state power flow that meets the normal operation of the power grid;

[0091] A second calculation module 403, configured to disconnect all the branch elements within the research scope of the power grid in sequence according to the fault N-1 mode, and perform N power flow calculations to obtain N power flow calculation results;

[0092] A third calculation module 404, configured to determine the vector P of each power flow section according to the base state power flow and the number of transmission channels for each power flow section 0_i , and determine the vector P of each power flow section according to the nth power flow calculation result and the number of transmission channels for each power flow section n_i , where 1 ≤ i ≤ I, 1 ≤ n ≤ N;

[0093] A fourth calculation module 405, configured to calculate the vector angle between the power flow of each power flow section in the nth fault N-1 mode and the base state power flow according to the vectors P n_i and P 0_i ;

[0094] A result output module 406, configured to determine that the base state power flow meets the static security analysis requirements for the research scope of the power grid in response to the comparison result that all the vector angles are less than the set angle threshold.

[0095] Preferably, the first calculation module 402 performs a power flow calculation based on the configured base state power flow data to determine the base state power flow that satisfies the normal operation of the power grid, including:

[0096] Performing a power flow calculation based on the configured base state power flow data to obtain the base state power flow calculation result;

[0097] According to the base state power flow calculation result, determining the working state of the branch elements of each transmission channel in each power flow section, where the working state includes a normal state and an abnormal state;

[0098] When all the branch elements within the power grid research scope are in the normal state, it is determined that the base state power flow obtained based on the configured base state power flow data satisfies the normal operation of the power grid; otherwise, after adjusting the configured base state power flow data, perform the power flow calculation again until all the branch elements within the power grid research scope are in the normal state.

[0099] Preferably, the third calculation module 404 determines the vector P of each power flow section according to the base state power flow and the number of transmission channels in each power flow section 0_i and determines the vector P of each power flow section according to the nth power flow calculation result and the number of transmission channels in each power flow section n_i The expressions are respectively:

[0100]

[0101]

[0102] In the formula, P 0_i and P n_i are respectively the vectors of the power flow of the i-th power flow section under the base state power flow and the fault N-1 mode, 1≤j≤J i and J i is the number of transmission channels in the i-th power flow section; P 0_ij and P n_ij are respectively the sum of the active powers of all the branch roads of the j-th transmission channel in the power flow of the i-th power flow section under the base state power flow and the fault N-1 mode.

[0103] Preferably, the fourth calculation module 405 calculates the vector included angle between the power flow of each power flow section and the base state power flow under the nth fault N-1 mode according to the vectors P 0_i and P n_i The calculation formula is:

[0104]

[0105] In the formula, θ n_i is the vector included angle between the power flow of the i-th power flow section and the base state power flow under the nth fault N-1 mode.

[0106] Preferably, the result output module 406 is further configured to:

[0107] When the comparison result is that there is at least one vector angle not less than the set angle threshold, check all branch elements of the power flow section where the at least one vector angle is located. Only when all branch elements are in a normal state, it is determined that the base state power flow meets the static security analysis requirements of the power grid research scope; otherwise, the base state power flow does not meet the static security analysis requirements of the power grid research scope.

[0108] The steps for the static security assessment device of the clean energy base transmitted through the flexible DC transmission system to determine whether the base state power flow data meets the static security analysis requirements in this preferred embodiment are the same as those of the static security assessment method of the clean energy base transmitted through the flexible DC transmission system of the present invention, and the achieved technical effects are also the same, so they will not be elaborated here.

[0109] Exemplary electronic device

[0110] Figure 5 It is a schematic structural diagram of an electronic device according to a preferred embodiment of the present invention. The electronic device can be any one or both of the first device and the second device, or a stand-alone device independent of them. The stand-alone device can communicate with the first device and the second device to receive the input signals collected from them. Figure 5 The block diagram of an electronic device according to an embodiment of the present disclosure is illustrated. As Figure 5 shown, the electronic device includes one or more processors 501 and a memory 502.

[0111] The processor 501 can be a central processing unit (CPU) or other forms of processing units with data processing capabilities and / or instruction execution capabilities, and can control other components in the electronic device to perform desired functions.

[0112] The memory 502 may include one or more computer program products, and the computer program products may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory, etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage media, and the processor 501 may run the program instructions to implement the energy consumption anomaly diagnosis method based on the enterprise energy consumption space and / or other desired functions of the various disclosed embodiments described above. In one example, the electronic device may further include: an input device 503 and an output device 504, and these components are interconnected through a bus system and / or other forms of connection mechanisms (not shown).

[0113] In addition, the input device 503 may further include, for example, a keyboard, a mouse, and so on.

[0114] The output device 504 may output various information to the outside. The output device 504 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, and so on.

[0115] Of course, for simplicity, Figure 5 only some of the components related to the present disclosure in the electronic device are shown, and components such as buses, input / output interfaces, and so on are omitted. In addition, according to specific application scenarios, the electronic device may further include any other appropriate components.

[0116] Exemplary computer program product and computer-readable storage medium

[0117] In addition to the above methods and devices, the embodiments of the present disclosure may also be computer program products, which include computer program instructions that, when run by a processor, cause the processor to execute the steps in the static security assessment method of the flexible DC transmission system for a clean energy base according to various embodiments of the present disclosure described in the "Exemplary Method" section above of this specification.

[0118] The computer program products may be written in any combination of one or more programming languages for programming code to perform the operations of the embodiments of the present disclosure. The programming languages include object-oriented programming languages, such as Java, C++, etc., and also include conventional procedural programming languages, such as the "C" language or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, executed as an independent software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0119] In addition, an embodiment of the present disclosure may also be a computer-readable storage medium storing computer program instructions, which, when run by a processor, cause the processor to execute the steps in the static security assessment method of the flexible DC transmission system for a clean energy base according to various embodiments of the present disclosure described in the above "Exemplary Method" section of this specification.

[0120] The computer-readable storage medium may adopt any combination of one or more readable media. The readable media may be a readable signal medium or a readable storage medium. The readable storage medium may, for example, include but is not limited to an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (non-exhaustive list) of the readable storage medium include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0121] The basic principles of the present disclosure have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, benefits, effects, etc. mentioned in the present disclosure are only examples and not limitations, and it cannot be considered that these advantages, benefits, effects, etc. are essential for each embodiment of the present disclosure. In addition, the above specific details of the disclosure are only for the purposes of illustration and facilitating understanding, rather than limitations, and the above details do not limit the present disclosure to necessarily adopt the above specific details for implementation.

[0122] Each embodiment in this specification is described in a progressive manner, and the key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other. For system embodiments, since they basically correspond to method embodiments, the description is relatively simple, and reference can be made to the partial description of the method embodiments for relevant parts.

[0123] The block diagrams of the devices, apparatuses, equipment, and systems involved in the present disclosure are only illustrative examples and do not intend to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any way. Words such as "including", "comprising", "having", etc. are open-ended terms, meaning "including but not limited to", and can be used interchangeably with each other. The words "or" and "and" used herein refer to the phrase "and / or" and can be used interchangeably with each other unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to" and can be used interchangeably with each other.

[0124] The apparatus and method of the present disclosure can be implemented in many ways. For example, the apparatus and method of the present disclosure can be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above order of steps for the method is for illustrative purposes only, and the steps of the method of the present disclosure are not limited to the specific order described above, unless otherwise specifically stated. In addition, in some embodiments, the present disclosure can also be implemented as a program recorded in a recording medium, and these programs include machine-readable instructions for implementing the method according to the present disclosure. Thus, the present disclosure also covers a recording medium storing a program for executing the method according to the present disclosure.

[0125] It should also be noted that in the apparatus, device, and method of the present disclosure, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of the present disclosure. The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects are very obvious to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown herein, but to the broadest scope consistent with the principles and novel features disclosed herein.

[0126] The above description has been given for purposes of illustration and description. In addition, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A static safety assessment method for a clean energy base through a flexible direct current transmission system, characterized in that: The method comprises: Obtain the number of flow sections I and the number of transmission channels of each flow section in the research scope of the power grid where the clean energy base is located through the flexible direct current transmission system, as well as the number of branch components of each transmission channel; Perform power flow calculation based on the configured base state power flow data to determine the base state power flow that satisfies the normal operation of the power grid; All branch elements within the research scope of the power grid are disconnected in sequence according to the fault N-1 mode, and N power flow calculations are performed to obtain N power flow calculation results; The vector P of each flow section is determined according to the base state flow and the number of transmission channels of each flow section. 0_i , and determine the vector P of each flow section according to the nth flow calculation result and the number of transmission channels of each flow section n_i , where 1≤i≤I, 1≤n≤N; According to the vector P n_i and P 0_i Calculate the vector angle between the power flow and the base state power flow in each power flow section under the nth fault N-1 mode; In response to the comparison result that all the vector angles are smaller than a set angle threshold, it is determined that the base state power flow meets the static safety analysis requirements of the power grid research scope.

2. The method according to claim 1, characterized in that The flow calculation is performed according to the configured base state flow data to determine the base state flow that satisfies the normal operation of the power grid, including: Perform power flow calculation according to the configured base state power flow data and obtain the base state power flow calculation results; Determine the working state of the branch element of each power transmission channel in each power flow section according to the base state power flow calculation result, wherein the working state includes a normal state and an abnormal state; When all branch elements within the research scope of the power grid are in normal state, it is determined that the base state flow obtained according to the configured base state flow data meets the normal operation of the power grid; otherwise, the configured base state flow data is adjusted and the flow calculation is re-performed until all branch elements within the research scope of the power grid are in normal state.

3. The method according to claim 1, characterized in that The vector P of each flow section is determined according to the base state flow and the number of transmission channels of each flow section. 0_i , and determine the vector P of each flow section according to the nth flow calculation result and the number of transmission channels of each flow section n_i , whose expressions are: Where P 0_i and P n_i are the vectors of the base state flow and the flow under fault N-1 mode of the ith flow section, 1≤j≤J i , J i is the number of transmission channels in the ith power flow section; P 0_ij and P n_ij They are the sum of the active powers of all branches of the jth transmission channel at the i-th power flow section in the base state power flow and the power flow under the fault N-1 mode.

4. The method according to claim 1, characterized in that: According to the vector P 0_i and P n_i Calculate the vector angle between the power flow and the base state power flow in each power flow section under the nth fault N-1 mode. The calculation formula is: In the formula, θ n_i It is the vector angle between the power flow of the i-th power flow section under the n-1 fault mode and the base state power flow.

5. The method according to claim 1, characterized in that The method further comprises: When the comparison result is that there is at least one vector angle that is not less than the set angle threshold, all branch elements of the flow section where the at least one vector angle is located are checked. Only when all branch elements are in normal state, it is determined that the base state flow meets the static safety analysis requirements of the power grid research scope. Otherwise, the base state flow does not meet the static safety analysis requirements of the power grid research scope.

6. A static safety assessment device for a clean energy base through a flexible direct current transmission system, characterized in that: The device comprises: The data acquisition module is used to obtain the number of flow sections I and the number of transmission channels of each flow section in the research scope of the power grid where the clean energy base is located through the flexible direct current transmission system, as well as the number of branch components of each transmission channel; The first calculation module is used to perform power flow calculation according to the configured base state power flow data to determine the base state power flow that satisfies the normal operation of the power grid; The second calculation module is used to disconnect all branch elements in the research range of the power grid in sequence according to the fault N-1 mode, and perform N power flow calculations to obtain N power flow calculation results; The third calculation module is used to determine the vector P of each flow section according to the base state flow and the number of transmission channels of each flow section. 0_i , and determine the vector P of each flow section according to the nth flow calculation result and the number of transmission channels of each flow section n_i , where 1≤i≤I, 1≤n≤N; The fourth calculation module is used to calculate the vector P n_i and P 0_i Calculate the vector angle between the power flow and the base state power flow in each power flow section under the nth fault N-1 mode; The result output module is used to respond to the comparison result that all the vector angles are smaller than the set angle threshold, and determine that the base state power flow meets the static safety analysis requirements of the power grid research scope.

7. The device according to claim 6, characterized in that The first calculation module performs power flow calculation according to the configured base state power flow data to determine the base state power flow that satisfies the normal operation of the power grid, including: Perform power flow calculation according to the configured base state power flow data and obtain the base state power flow calculation results; Determine the working state of the branch element of each power transmission channel in each power flow section according to the base state power flow calculation result, wherein the working state includes a normal state and an abnormal state; When all branch elements within the research scope of the power grid are in normal state, it is determined that the base state flow obtained according to the configured base state flow data meets the normal operation of the power grid; otherwise, the configured base state flow data is adjusted and the flow calculation is re-performed until all branch elements within the research scope of the power grid are in normal state.

8. The device according to claim 6, characterized in that The third calculation module determines the vector P of each flow section according to the base state flow and the number of transmission channels of each flow section. 0_i , and determine the vector P of each flow section according to the nth flow calculation result and the number of transmission channels of each flow section n_i , whose expressions are: P 0_i =(P 0_i1 ,P 0_i2 ,…,P 0_ij ,…,P 0_iJi ) P n_i =(P n_i1 ,P n_i2 ,…,P n_ij ,…,P n_iJi ) Where P 0_i and P n_i are the vectors of the base state flow and the flow under fault N-1 mode of the ith flow section, 1≤j≤J i , J i is the number of transmission channels in the ith power flow section; P 0_ij and P n_ij They are the sum of the active powers of all branches of the jth transmission channel at the i-th power flow section in the base state power flow and the power flow under the fault N-1 mode.

9. The device according to claim 6, characterized in that The fourth calculation module calculates the vector P 0_i and P n_i Calculate the vector angle between the power flow and the base state power flow in each power flow section under the nth fault N-1 mode. The calculation formula is: In the formula, θ n_i It is the vector angle between the power flow of the i-th power flow section under the n-1 fault mode and the base state power flow.

10. The device according to claim 6, characterized in that The result output module is also used for: When the comparison result is that there is at least one vector angle that is not less than the set angle threshold, all branch elements of the flow section where the at least one vector angle is located are checked. Only when all branch elements are in normal state, it is determined that the base state flow meets the static safety analysis requirements of the power grid research scope. Otherwise, the base state flow does not meet the static safety analysis requirements of the power grid research scope.

11. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and the computer program is used to execute the method according to any one of claims 1 to 5.

12. An electronic device, characterized in that: The electronic device comprises: processor; a memory for storing instructions executable by the processor; The processor is used to read the executable instructions from the memory and execute the instructions to implement the method described in any one of claims 1 to 5.

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