Method and device for identifying equivalent parameters of power grid in transient process of double-high power system

Abstract

The invention relates to the technical field of electric power systems, in particular to an identification method and device for power grid equivalent parameters in the transient process of a double-high electric power system, and the method comprises the steps: collecting the actual voltage data, actual current data and actual power data of a power grid in the transient process of the electric power system; performing target processing on the actual voltage data, the actual current data and the actual power data to obtain processed voltage data, processed current data and processed power data; and based on the processed voltage data, the processed current data and the processed power data, constructing a target multivariate nonlinear power flow equation set so as to identify the equivalent potential, the equivalent resistance and the equivalent reactance of the power grid in the transient process by using the target multivariate nonlinear power flow equation set. Therefore, the problems that in the prior art, the requirement for the sampling frequency is strict, the accuracy and stability of an identification result are reduced, and the safety and reliability of a power system are reduced are solved.

Description

Technical Field

[0001] The present application relates to the technical field of power systems, and in particular to a method and device for identifying equivalent parameters of a power grid in a transient process of a dual-high power system. Background Art

[0002] In the "double high" power system, the importance of transient voltage and frequency stability analysis, evaluation and control is increasing. Real-time identification of equivalent parameters of power grid refers to the use of advanced measurement technology and data analysis methods to dynamically determine the equivalent impedance and equivalent electromotive force of the system during the operation of the power system. This technology is crucial for real-time monitoring, fault diagnosis, voltage and frequency stability evaluation and optimization control of power systems.

[0003] When the power system is subject to a large disturbance (such as a short circuit, line break, etc.), the voltage, power and other electrical quantities in the system will undergo a transient change process. The real-time identification technology of the equivalent parameters of the transient process power grid can extract the relevant information of the equivalent parameters of the power grid by measuring and analyzing the changes in these electrical quantities, so as to grasp the changes of the external power grid in the transient process in real time. The accurate identification of the equivalent parameters of the power grid in the transient process of the "double-high" power system is of great significance for realizing the real-time analysis and control of the transient process of the power system to ensure the stability of the system. Therefore, in the relevant technology, the real-time identification method of the equivalent parameters of the power grid mainly includes two types: the identification method based on two-point power flow and the identification method based on least squares.

[0004] However, the two-point power flow method is prone to parameter drift problems when the values ​​of two adjacent sampling points are very close. This method has strict requirements on the sampling frequency, which must be close but avoid the 0 / 0 mode. The least squares-based identification method is greatly affected by noise, which may cause the identification results to deviate from the true value, thereby affecting the accuracy of identification. When only small disturbances or no disturbances occur inside the system, the identification is more accurate, but it is not suitable for parameter identification of transient processes. If the initial value is not selected properly, the identification process may fall into a local optimal solution or fail to converge to the global optimal solution, which will reduce the reliability and stability of the identification results and needs to be improved urgently. Summary of the invention

[0005] The present application provides a method and device for identifying equivalent parameters of the power grid in a transient process of a dual-high power system, so as to solve the problems in the related art that the method based on two-point power flow is prone to parameter drift when the sampling point values ​​are close, has strict requirements on the sampling frequency, and the identification method based on least squares is greatly affected by noise, which reduces the accuracy and stability of the identification results, and reduces the safety and reliability of the power system.

[0006] The first aspect of the present application provides a method for identifying equivalent parameters of the power grid in a transient process of a dual-high power system, comprising the following steps: collecting actual voltage data, actual current data and actual power data of the power grid when the power system is in a transient process; performing target processing on the actual voltage data, the actual current data and the actual power data to obtain processed voltage data, processed current data and processed power data; constructing a target multivariate nonlinear power flow equation group based on the processed voltage data, the processed current data and the processed power data, so as to use the target multivariate nonlinear power flow equation group to identify the equivalent potential, equivalent resistance and equivalent reactance of the power grid in the transient process.

[0007] Optionally, in one embodiment of the present application, the target processing of the actual voltage data, the actual current data and the actual power data to obtain processed voltage data, processed current data and processed power data includes: filtering the actual voltage data, the actual current data and the actual power data to obtain filtered voltage data, filtered current data and filtered power data; and respectively calculating the target sliding averages of the filtered voltage data, the filtered current data and the filtered power data to obtain the processed voltage data, the processed current data and the processed power data.

[0008] Optionally, in one embodiment of the present application, the identification of the equivalent potential, equivalent resistance and equivalent reactance of the power grid during the transient process by using the target multivariate nonlinear power flow equation group includes: iteratively solving the target multivariate nonlinear power flow equation group to obtain an iterative solution result; detecting whether the iterative solution result satisfies a preset iteration stop condition; when it is detected that the iterative solution result satisfies the preset iteration stop condition, stopping the iteration and outputting the equivalent potential, the equivalent resistance and the equivalent reactance of the power grid during the transient process.

[0009] Optionally, in one embodiment of the present application, the target multivariate nonlinear power flow equations are:

[0010]

[0011] Among them, R(i) is the real-time identification value of the equivalent resistance of the power grid; X(i) is the real-time identification value of the equivalent reactance of the power grid; E(i) is the real-time identification value of the equivalent potential of the power grid.

[0012] Optionally, in one embodiment of the present application, the solution formula of the target Newton iteration method is:

[0013] W k+1 (i) = Wk (i)-J k (i) -1 ·F k (i)

[0014] Among them, J k (i) is the Jacobian matrix used for solving the kth iteration at the i-th moment; F k (i) is the value of the power flow equation solved at the kth iteration at the i-th moment; W k (i) is the k-th iteration solution process at the i-th moment. k (i) X k (i) E k (i) The equivalent parameter phasor of the power grid composed; W k+1 (i) is the k+1th iteration solution process at the i-th moment. k+1 (i) X k+1 (i) E k+1 (i) The equivalent parameter phasors of the power grid.

[0015] The second aspect of the present application provides an identification device for equivalent parameters of a power grid in a transient process of a dual-high power system, including: an acquisition module for acquiring actual voltage data, actual current data and actual power data of a power grid when the power system is in a transient process; a processing module for performing target processing on the actual voltage data, the actual current data and the actual power data to obtain processed voltage data, processed current data and processed power data; an identification module for constructing a target multivariate nonlinear power flow equation group based on the processed voltage data, the processed current data and the processed power data, so as to use the target multivariate nonlinear power flow equation group to identify the equivalent potential, equivalent resistance and equivalent reactance of the power grid in the transient process.

[0016] Optionally, in one embodiment of the present application, the processing module includes: a first processing unit, used to filter the actual voltage data, the actual current data and the actual power data to obtain filtered voltage data, filtered current data and filtered power data; a second processing unit, used to respectively calculate the target sliding averages of the filtered voltage data, the filtered current data and the filtered power data to obtain the processed voltage data, the processed current data and the processed power data.

[0017] Optionally, in one embodiment of the present application, the identification module includes: a calculation unit, used to iteratively solve the target multivariate nonlinear power flow equation group to obtain an iterative solution result; a detection unit, used to detect whether the iterative solution result satisfies a preset iteration stop condition; an acquisition unit, used to stop iteration and output the equivalent potential, the equivalent resistance and the equivalent reactance of the power grid during the transient process when it is detected that the iterative solution result satisfies the preset iteration stop condition.

[0018] Optionally, in one embodiment of the present application, the target multivariate nonlinear power flow equations are:

[0019]

[0020] Among them, R(i) is the real-time identification value of the equivalent resistance of the power grid; X(i) is the real-time identification value of the equivalent reactance of the power grid; E(i) is the real-time identification value of the equivalent potential of the power grid.

[0021] Optionally, in one embodiment of the present application, the solution formula of the target Newton iteration method is:

[0022] W k+1 (i) = W k (i)-J k (i) -1 ·F k (i)

[0023] Among them, J k (i) is the Jacobian matrix used for solving the kth iteration at the i-th moment; F k (i) is the value of the power flow equation solved at the kth iteration at the i-th moment; W k (i) is the k-th iteration solution process at the i-th moment. k (i) X k (i) E k (i) The equivalent parameter phasor of the power grid composed; W k+1 (i) is the k+1th iteration solution process at the i-th moment. k+1 (i) X k+1 (i) E k+1 (i) The equivalent parameter phasors of the power grid.

[0024] The third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for identifying grid equivalent parameters of a transient process of a dual-high power system as described in the above embodiment.

[0025] The fourth aspect of the present application provides a computer-readable storage medium, which stores a computer program. When the program is executed by a processor, it implements the above method for identifying grid equivalent parameters of a transient process of a dual-high power system.

[0026] The fifth aspect of the present application provides a computer program product, including a computer program, which, when executed, is used to implement the above method for identifying grid equivalent parameters of a transient process of a dual-high power system.

[0027] The embodiment of the present application can target process the actual voltage data, actual current data and actual power data of the power grid collected during the transient process of the power system to obtain processed voltage data, processed current data and processed power data, so as to construct a target multivariate nonlinear power flow equation group, and use the target multivariate nonlinear power flow equation group to identify the equivalent potential, equivalent resistance and equivalent reactance of the power grid during the transient process, effectively improving the accuracy and stability of the identification results. Thus, the problems of strict requirements on sampling frequency in related technologies, reduced accuracy and stability of identification results, and reduced safety and reliability of power systems are solved.

[0028] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0030] Figure 1 A flowchart of a method for identifying grid equivalent parameters of a dual-high power system transient process provided according to an embodiment of the present application;

[0031] Figure 2 This is a flow chart of a method for identifying grid equivalent parameters in a transient process of a dual-high power system according to a specific embodiment of the present application;

[0032] Figure 3 A schematic diagram of the identification of equivalent parameters of the external power grid at the grid connection point for a transient process of a large-scale wind power transmission line failure according to a specific embodiment of the present application;

[0033] Figure 4 A schematic diagram of an equivalent potential E, an equivalent resistance R and an equivalent reactance X of an external power grid of a 35 kV grid connection point of a wind farm for identification of equivalent parameters in a specific embodiment of the present application;

[0034] Figure 5A schematic diagram of the structure of a device for identifying grid equivalent parameters of a dual-high power system transient process provided according to an embodiment of the present application;

[0035] Figure 6 It is a schematic diagram of the structure of an electronic device provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0036] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0037] The following describes the method and device for identifying equivalent parameters of the power grid in the transient process of the dual-high power system of the embodiment of the present application with reference to the accompanying drawings. In view of the problems that the sampling frequency requirements in the related technologies mentioned in the background technology center are relatively strict, the accuracy and stability of the identification results are reduced, and the safety and reliability of the power system are reduced, the present application provides a method for identifying equivalent parameters of the power grid in the transient process of the dual-high power system, in which the actual voltage data, actual current data and actual power data of the power grid collected in the transient process of the power system can be processed to obtain the processed voltage data, the processed current data and the processed power data, so that the target multivariate nonlinear power flow equation group can be constructed to use the target multivariate nonlinear power flow equation group to identify the equivalent potential, equivalent resistance and equivalent reactance of the power grid in the transient process, effectively improving the accuracy and stability of the identification results. As a result, the problems that the sampling frequency requirements in the related technologies are relatively strict, the accuracy and stability of the identification results are reduced, and the safety and reliability of the power system are reduced are solved.

[0038] Specifically, Figure 1 A flow chart of a method for identifying grid equivalent parameters in a transient process of a dual-high power system provided in an embodiment of the present application.

[0039] like Figure 1 As shown, the method for identifying the equivalent parameters of the power grid in the transient process of the dual-high power system includes the following steps:

[0040] In step S101, actual voltage data, actual current data and actual power data of the power grid are collected when the power system is in a transient state.

[0041] It can be understood that the embodiments of the present application can collect the actual voltage data, actual current data and actual power data of the power grid when the power system is in a transient process. For example, when the power system is in a transient process, due to the action of the unloading circuit, high-frequency components will appear in the active power, reactive power and voltage. First, the embodiments of the present application can collect real-time data such as voltage, current, active power, reactive power, etc. during the transient process to monitor the power system in real time and improve the accuracy of the identification results.

[0042] In step S102, the actual voltage data, the actual current data and the actual power data are subjected to target processing to obtain processed voltage data, processed current data and processed power data.

[0043] It can be understood that the embodiments of the present application can perform target processing on the actual voltage data, actual current data and actual power data. For example, the data filtering and smoothing processing in the following steps can be performed to obtain processed voltage data, processed current data and processed power data, thereby effectively improving the accuracy and reliability of the data.

[0044] Optionally, in one embodiment of the present application, the actual voltage data, the actual current data and the actual power data are subjected to target processing to obtain processed voltage data, processed current data and processed power data, including: filtering the actual voltage data, the actual current data and the actual power data to obtain filtered voltage data, filtered current data and filtered power data; and respectively calculating the target sliding averages of the filtered voltage data, the filtered current data and the filtered power data to obtain processed voltage data, processed current data and processed power data.

[0045] For example, when the power system in the embodiment of the present application is in a transient process, due to the action of the unloading circuit, high-frequency components will appear in the active power, reactive power, and voltage. First, the real-time collected active power, reactive power, and voltage data are filtered using a first-order or second-order low-pass digital filter.

[0046] Among them, when a first-order filter is used for filtering, then:

[0047]

[0048] Among them, α is the coefficient of the first-order filter; U1(i), P1(i), Q1(i), (i=1…n) are the collected original voltage, active power, and reactive power data respectively; U2(i), P2(i), Q2(i), (i=1…n) are the filtered voltage, active power, and reactive power data.

[0049] When a second-order filter is used for filtering, then:

[0050]

[0051] Among them, b0, b1, b2 are the numerator coefficients of the second-order filter; c1, c2 are the denominator coefficients of the second-order filter, U1(i), P1(i), Q1(i), (i=1...n) are the collected original voltage, active power, and reactive power data, respectively; U2(i), P2(i), Q2(i), (i=1...n) are the filtered voltage, active power, and reactive power data.

[0052] Next, the embodiment of the present application can calculate the sliding average of the filtered data respectively, wherein the sliding window size can be dynamically adjusted according to the characteristics of the signal. The formula can be expressed as:

[0053]

[0054] Among them, U3(i), P3(i), Q3(i) are the sliding average values ​​of voltage, active power, and reactive power respectively; N is the sliding window data length.

[0055] In addition, the embodiment of the present application can also filter and smooth the actual current, which will not be elaborated in detail here, to effectively remove noise and high-frequency components in the current data, thereby obtaining smoother and more reliable current data.

[0056] In step S103, a target multivariate nonlinear power flow equation group is constructed based on the processed voltage data, the processed current data and the processed power data, so as to use the target multivariate nonlinear power flow equation group to identify the equivalent potential, equivalent resistance and equivalent reactance of the power grid during the transient process.

[0057] It can be understood that the embodiment of the present application can construct a target multivariate nonlinear power flow equation group based on the processed voltage data, the processed current data and the processed power data. For example, the embodiment of the present application can obtain an equation containing the equivalent potential E, the equivalent resistance R and the equivalent reactance X of the power grid according to the power flow calculation formula, that is:

[0058]

[0059] Among them, E is the equivalent potential of the power grid; R is the equivalent resistance of the power grid; X is the equivalent reactance of the power grid; P is the active power value output by the node after data processing; Q is the reactive power value output by the node after data processing; U is the voltage value of the node after data processing; δ is the angle between the equivalent potential of the power grid and the node voltage, that is, the power angle.

[0060] Next, eliminating the power angle δ, we get:

[0061]

[0062] Substituting the three sets of voltage data, active power data, and reactive power data obtained in the above steps after filtering and smoothing into formula (5), assuming that the equivalent parameters of the power grid remain unchanged, we can obtain:

[0063]

[0064] Among them, P 31 (i) P 32 (i) P 33 (i) are the three sets of active power values ​​output by the node after data processing; Q 31 (i) Q 32 (i) Q 33 (i) are three sets of reactive power values ​​output by the node after data processing; U 31 (i) U 32 (i) U 33 (i) are the three sets of voltage values ​​of the nodes after data processing; R(i) is the real-time identification value of the equivalent resistance of the power grid; X(i) is the real-time identification value of the equivalent reactance of the power grid; E(i) is the real-time identification value of the equivalent potential of the power grid.

[0065] Next, the multivariate nonlinear power flow equations obtained in the above steps, including the real-time parameters R(i), X(i), and E(i) of the transient power grid, are sorted out to obtain the following equation:

[0066]

[0067] Among them, R(i) is the real-time identification value of the equivalent resistance of the power grid; X(i) is the real-time identification value of the equivalent reactance of the power grid; E(i) is the real-time identification value of the equivalent potential of the power grid.

[0068] in,

[0069]

[0070] The left side of the equation system is recorded as F(i), that is:

[0071] F(i)=a m1 [R(i) 2 +X(i) 2 ]+a m2 R(i)X(i)+a m3 R(i)+a m4 X(i)-E(i) 2 +a 15 m=(1,2,3)(9)

[0072] Next, the transient process power grid equivalent real-time parameters R(i), X(i), E(i) are organized into vector form, namely:

[0073]

[0074] Among them, W k (i) is the k-th iteration solution process at the i-th moment. k (i) X k (i) E k (i) The equivalent parameter phasors of the power grid.

[0075] in,

[0076]

[0077] Where W k+1 (i) is the k+1th iteration solution process at the i-th moment. k+1 (i) X k+1 (i) E k+1 (i) The equivalent parameter phasors of the power grid.

[0078] Therefore, the embodiment of the present application can use the Newton iteration method in the following steps to solve the target multivariate nonlinear power flow equations, and then identify the equivalent potential, equivalent resistance and equivalent reactance of the power grid during the transient process, and provide guidance for the system voltage and frequency stability assessment and optimization control to improve the safety and stability of the power system.

[0079] Optionally, in one embodiment of the present application, the equivalent potential, equivalent resistance and equivalent reactance of the power grid during the transient process are identified by utilizing the target multivariate nonlinear power flow equation group, including: iteratively solving the target multivariate nonlinear power flow equation group to obtain an iterative solution result; detecting whether the iterative solution result satisfies a preset iteration stop condition; when it is detected that the iterative solution result satisfies the preset iteration stop condition, stopping the iteration and outputting the equivalent potential, equivalent resistance and equivalent reactance of the power grid during the transient process.

[0080] For example, the embodiment of the present application can use the Newton iteration method to solve formula (7), that is, to solve the multivariate nonlinear power flow equations, then:

[0081] W k+1(i) =W k(i) -J k(i) -1 ·F k (i) (12)

[0082] Among them, J k (i) is the Jacobian matrix used for solving the kth iteration at the i-th moment; F k(i) is the value of the power flow equation solved at the kth iteration at the i-th moment; W k (i) is the k-th iteration solution process at the i-th moment. k (i) X k (i) E k (i) The equivalent parameter phasor of the power grid composed; W k+1 (i) is the k+1th iteration solution process at the i-th moment. k+1 (i) X k+1 (i) E k+1 (i) The equivalent parameter phasors of the power grid.

[0083] in,

[0084] J k (i) = [2a m1 R(i)+a m2 X(i)+a m3 -2E(i)] (m=1,2,3) (13)

[0085] F k (i) = a m1 [R k (i) 2 +X k (i) 2 ]+a m2 R k (i)X k (i)+a m3 R k (i)+a m4 X k (i)-E k (i) 2 +a 15 m=(1,2,3) (14)

[0087] The Newton iteration method is used to identify the equivalent parameters of the power grid in real time. The equivalent parameters of the power grid include the equivalent potential E, the equivalent resistance R, and the equivalent reactance X. The criterion for stopping the iteration can be one or more of the following. When the criterion condition is met, an iteration stop signal is issued, and the equivalent parameters W of the power grid identified at that moment are output. k (i).

[0088] Among them, the first one is the iteration number criterion: when the iteration number reaches the maximum number of iterations, the iteration is stopped, that is:

[0089]

[0090] Among them, C1 is the first iteration stop criterion, n is the number of iterations, and N0 is the maximum number of iterations.

[0091] The second is to judge the change of function value: when the difference of function value between two iterations is within a certain range, stop the iteration, that is:

[0092]

[0093] Among them, C2 is the second iteration stop criterion, and ε is the threshold of the difference between two iteration functions.

[0094] The third is function value judgment: when the function value is close to 0, stop iteration, that is:

[0095]

[0096] Among them, C3 is the stopping criterion of the third iteration, and σ is the threshold of the interpolation between the function value and 0.

[0097] Then the final iteration stop synthesis signal can be expressed as:

[0098]

[0099] Among them, C is the final iteration stop signal; M is the number of satisfied judgment conditions, which can be set to 1, 2, or 3 according to actual conditions.

[0100] When C is 1, the iteration stops and the grid equivalent parameter W identified at that moment is output. k (i).

[0101] Therefore, the embodiments of the present application can provide guidance for system voltage and frequency stability assessment and optimization control by effectively identifying the equivalent potential, equivalent resistance R and equivalent reactance of the power grid during transient processes in real time, so as to improve the safety and stability of the power system.

[0102] For example, Figure 2 As shown, the working principle of the embodiment of the present application is described in detail below with a specific embodiment.

[0103] Step S201: collecting voltage, current and power data, that is, collecting real-time data of voltage, current and power of the power grid during transient process.

[0104] Step S202: filtering with a first-order or second-order low-pass filter, that is, filtering the collected real-time data with a first-order or second-order low-pass filter to obtain filtered data.

[0105] Step S203: Calculate the sliding average of the data, that is, calculate the sliding average of the filtered data.

[0106] Step S204: reading three sets of power flow data, that is, reading three sets of voltage, active power, and reactive power data after filtering and smoothing.

[0107] Step S205: constructing a multivariate nonlinear power flow equation group, that is, constructing a multivariate nonlinear power flow equation group including the transient process power grid equivalent real-time parameters R(i), X(i), E(i).

[0108] Step S206: Newton iteration method is used to identify the equivalent parameters of the power grid, that is, the Newton iteration method is used to solve the multivariate nonlinear power flow equations, so as to identify the equivalent parameters of the power grid R(i), X(i), and E(i).

[0109] Step S207: Determine whether the iteration stop condition C=1 is satisfied. If the iteration stop condition C=1 is satisfied, execute step S209; otherwise, execute step S208.

[0110] Step S208: Continue iteration, that is, execute step S207 and continue iteration.

[0111] Step S209: outputting the i-th group of grid equivalent parameters R(i), X(i), E(i).

[0112] Step S210: Determine whether the real-time identification is finished. If the real-time identification is finished, the iteration is finished. Otherwise, execute step S211.

[0113] Step S211: i=i+1, namely, continue to identify the grid equivalent parameters R(i), X(i), E(i).

[0114] Step S212: Read the next set of power flow data and construct the next multivariate nonlinear power flow equation group.

[0115] For example, Figure 3 As shown, Figure 3 This is a schematic diagram of the identification of equivalent parameters of the external power grid at the grid connection point during the transient process of a large-scale wind power transmission line failure in this application. The embodiment of this application can collect real-time data such as voltage, current, power, etc. during the transient process, and filter and smooth the data to construct a multivariate nonlinear power flow equation group containing equivalent parameters of the power grid, and then use the Newton iteration method to solve the multivariate nonlinear power flow equation group to identify the equivalent potential E, equivalent resistance R and equivalent reactance X of the power grid during the transient process, such as Figure 4 The equivalent parameters identified for this application are a schematic diagram of the equivalent potential E, equivalent resistance R and equivalent reactance X of the external power grid of the 35kV grid-connected point of the wind farm. It can be seen that the embodiment of the present application can effectively identify the equivalent potential, equivalent resistance and equivalent reactance of the power grid in the transient process in real time, improve the reliability of the identification results, effectively prevent the occurrence of accidents, and improve the safety and reliability of the power grid.

[0116] According to the identification method of equivalent parameters of the power grid in the transient process of the dual-high power system proposed in the embodiment of the present application, the actual voltage data, actual current data and actual power data of the power grid collected in the transient process of the power system can be processed to obtain processed voltage data, processed current data and processed power data, so as to construct a target multivariate nonlinear power flow equation group, and use the target multivariate nonlinear power flow equation group to identify the equivalent potential, equivalent resistance and equivalent reactance of the power grid in the transient process, effectively improving the accuracy and stability of the identification results. Therefore, the problems of strict requirements on sampling frequency in related technologies, reduced accuracy and stability of identification results, and reduced safety and reliability of power systems are solved.

[0117] Next, a device for identifying grid equivalent parameters of a dual-high power system transient process proposed in an embodiment of the present application will be described with reference to the accompanying drawings.

[0118] Figure 5 It is a block diagram of a device for identifying grid equivalent parameters of a dual-high power system transient process according to an embodiment of the present application.

[0119] like Figure 5 As shown, the device 10 for identifying grid equivalent parameters of a dual-high power system transient process includes: a collection module 100 , a processing module 200 and an identification module 300 .

[0120] Specifically, the acquisition module 100 is used to acquire actual voltage data, actual current data and actual power data of the power grid when the power system is in a transient state.

[0121] The processing module 200 is used to perform target processing on the actual voltage data, the actual current data and the actual power data to obtain processed voltage data, processed current data and processed power data.

[0122] The identification module 300 is used to construct a target multivariate nonlinear power flow equation group based on the processed voltage data, the processed current data and the processed power data, so as to use the target multivariate nonlinear power flow equation group to identify the equivalent potential, equivalent resistance and equivalent reactance of the power grid during the transient process.

[0123] Optionally, in one embodiment of the present application, the processing module 200 includes: a first processing unit and a second processing unit.

[0124] The first processing unit is used to filter the actual voltage data, the actual current data and the actual power data to obtain filtered voltage data, filtered current data and filtered power data.

[0125] The second processing unit is used to calculate the target sliding averages of the filtered voltage data, the filtered current data and the filtered power data respectively to obtain the processed voltage data, the processed current data and the processed power data.

[0126] Optionally, in one embodiment of the present application, the identification module 300 includes: a calculation unit, a detection unit and an acquisition unit.

[0127] The calculation unit is used to iteratively solve the target multivariate nonlinear power flow equations to obtain iterative solution results.

[0128] The detection unit is used to detect whether the iterative solution result meets the preset iteration stop condition.

[0129] The acquisition unit is used to stop the iteration when it is detected that the iterative solution result meets the preset iteration stop condition, and output the equivalent potential, equivalent resistance and equivalent reactance of the power grid during the transient process.

[0130] Optionally, in one embodiment of the present application, the target multivariate nonlinear power flow equations are:

[0131]

[0132] Among them, R(i) is the real-time identification value of the equivalent resistance of the power grid; X(i) is the real-time identification value of the equivalent reactance of the power grid; E(i) is the real-time identification value of the equivalent potential of the power grid.

[0133] Optionally, in one embodiment of the present application, the solution formula of the target Newton iteration method is:

[0134] W k+1 (i) = W k (i)-J k (i) -1 ·F k (i)

[0135] Among them, J k (i) is the Jacobian matrix used for solving the kth iteration at the i-th moment; F k (i) is the value of the power flow equation solved at the kth iteration at the i-th moment; W k (i) is the k-th iteration solution process at the i-th moment. k (i) X k (i) E k (i) The equivalent parameter phasor of the power grid composed; W k+1 (i) is the k+1th iteration solution process at the i-th moment. k+1 (i) X k+1 (i) E k+1 (i) The equivalent parameter phasors of the power grid.

[0136] It should be noted that the aforementioned explanation of the embodiment of the method for identifying equivalent parameters of the power grid in the transient process of a dual-high power system is also applicable to the device for identifying equivalent parameters of the power grid in the transient process of a dual-high power system of this embodiment, and will not be repeated here.

[0137] According to the identification device of the equivalent parameters of the power grid in the transient process of the dual-high power system proposed in the embodiment of the present application, the actual voltage data, actual current data and actual power data of the power grid collected in the transient process of the power system can be processed to obtain the processed voltage data, processed current data and processed power data, so as to construct the target multivariate nonlinear power flow equation group, and use the target multivariate nonlinear power flow equation group to identify the equivalent potential, equivalent resistance and equivalent reactance of the power grid in the transient process, effectively improving the accuracy and stability of the identification results. Therefore, the problems of strict requirements on sampling frequency in the related technology, reduced accuracy and stability of identification results, and reduced safety and reliability of the power system are solved.

[0138] Figure 6 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0139] A memory 601 , a processor 602 , and a computer program stored in the memory 601 and executable on the processor 602 .

[0140] When the processor 602 executes the program, the method for identifying the grid equivalent parameters of the transient process of the dual-high power system provided in the above embodiment is implemented.

[0141] Furthermore, the electronic device further comprises:

[0142] The communication interface 603 is used for communication between the memory 601 and the processor 602 .

[0143] The memory 601 is used to store computer programs that can be executed on the processor 602 .

[0144] The memory 601 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0145] If the memory 601, the processor 602 and the communication interface 603 are implemented independently, the communication interface 603, the memory 601 and the processor 602 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 6 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0146] Optionally, in a specific implementation, if the memory 601, the processor 602 and the communication interface 603 are integrated on a chip, the memory 601, the processor 602 and the communication interface 603 can communicate with each other through an internal interface.

[0147] The processor 602 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0148] This embodiment also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above method for identifying grid equivalent parameters of a transient process of a dual-high power system.

[0149] This embodiment also provides a computer program product, including a computer program, which, when executed, is used to implement the above method for identifying grid equivalent parameters of a dual-high power system transient process.

[0150] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0151] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0152] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0153] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

[0154] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one or a combination of the following technologies known in the art: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0155] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0156] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0157] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for identifying equivalent parameters of power grid in transient process of dual-high power system, characterized in that: The following steps are involved: Collect the actual voltage data, actual current data and actual power data of the power grid when the power system is in a transient state; The actual voltage data, the actual current data and the actual power data are subjected to target processing to obtain processed voltage data, processed current data and processed power data; Based on the processed voltage data, the processed current data and the processed power data, a target multivariate nonlinear power flow equation group is constructed to utilize the target multivariate nonlinear power flow equation group to identify the equivalent potential, equivalent resistance and equivalent reactance of the power grid during the transient process.

2. The method according to claim 1, characterized in that The target processing of the actual voltage data, the actual current data and the actual power data to obtain processed voltage data, processed current data and processed power data includes: Filtering the actual voltage data, the actual current data and the actual power data to obtain filtered voltage data, filtered current data and filtered power data; Target sliding averages of the filtered voltage data, the filtered current data, and the filtered power data are calculated respectively to obtain the processed voltage data, the processed current data, and the processed power data.

3. The method according to claim 1, characterized in that The method of identifying the equivalent potential, equivalent resistance and equivalent reactance of the power grid in the transient process by using the target multivariate nonlinear power flow equation group includes: Iteratively solving the target multivariate nonlinear power flow equations to obtain an iterative solution result; Detecting whether the iterative solution result satisfies a preset iterative stop condition; When it is detected that the iterative solution result satisfies the preset iterative stop condition, the iteration is stopped, and the equivalent potential, the equivalent resistance and the equivalent reactance of the power grid in the transient process are output.

4. The method according to claim 1, characterized in that: The target multivariate nonlinear power flow equations are: Among them, R(i) is the real-time identification value of the equivalent resistance of the power grid; X(i) is the real-time identification value of the equivalent reactance of the power grid; E(i) is the real-time identification value of the equivalent potential of the power grid.

5. The method according to claim 1, characterized in that The solution formula of the target Newton iteration method is: W k+1 (i)=W k (i)-J k (i) -1 F k (i) Among them, J k (i) is the Jacobian matrix used for solving the kth iteration at the i-th moment; F k (i) is the value of the power flow equation solved at the kth iteration at the i-th moment; W k (i) is the k-th iteration solution process at the i-th moment. k (i) X k (i) E k (i) The equivalent parameter phasor of the power grid composed; W k+1 (i) is the k+1th iteration solution process at the i-th moment. k+1 (i) X k+1 (i) E k+1 (i) The equivalent parameter phasors of the power grid.

6. A device for identifying equivalent parameters of power grid in transient process of dual-high power system, characterized in that: include: The acquisition module is used to collect the actual voltage data, actual current data and actual power data of the power grid when the power system is in a transient state; a processing module, configured to perform target processing on the actual voltage data, the actual current data and the actual power data to obtain processed voltage data, processed current data and processed power data; An identification module is used to construct a target multivariate nonlinear power flow equation group based on the processed voltage data, the processed current data and the processed power data, so as to use the target multivariate nonlinear power flow equation group to identify the equivalent potential, equivalent resistance and equivalent reactance of the power grid in the transient process.

7. The device according to claim 6, characterized in that The processing module comprises: A first processing unit, configured to filter the actual voltage data, the actual current data and the actual power data to obtain filtered voltage data, filtered current data and filtered power data; The second processing unit is used to calculate the target sliding averages of the filtered voltage data, the filtered current data and the filtered power data respectively to obtain the processed voltage data, the processed current data and the processed power data.

8. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for identifying equivalent parameters of the power grid in a transient process of a dual-high power system as described in any one of claims 1 to 5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the method for identifying equivalent parameters of a power grid in a transient process of a dual-high power system as described in any one of claims 1-5.

10. A computer program product, comprising a computer program, characterized in that The computer program is executed by a processor to implement the method for identifying equivalent parameters of a power grid in a transient process of a dual-high power system as described in any one of claims 1 to 5.

Images