Power network oscillation path identification method, device, equipment, medium and product

Abstract

The invention discloses a power network oscillation path identification method and device, equipment, a medium and a product, and the method comprises the steps: extracting a high-frequency oscillation signal in a voltage and current signal sampled from a power network based on a signal decomposition technology; calculating an electromagnetic field energy value array in different node resonance periods in the power network according to the high-frequency oscillation signal; calculating the oscillations of different nodes according to the electromagnetic field energy value array; and determining the oscillation path according to the magnitude sequence of the oscillations. According to the scheme, the oscillation path can be accurately detected.

Description

Technical Field

[0001] The present invention relates to the technical field of resonance stability, and particularly to a method, device, equipment, medium and product for identifying the oscillation path of a power network. Background Art

[0002] The tracing of the oscillation path of the power system is the basis for suppressing the generation and diffusion of broadband oscillations in a timely and effective manner. Accurate exploration of the oscillation path can give early warning of oscillation risks, and by adding damping control at weak nodes in the system, the further development of broadband oscillations can be effectively blocked.

[0003] Traditional oscillation path analysis methods based on fixed modes and fixed model parameters are difficult to accurately depict the development process of oscillations, resulting in difficulties in measuring and locating broadband oscillations, and the accuracy of the identified oscillation paths is relatively low. Summary of the Invention

[0004] In view of the above defects, the present invention provides a method, device, equipment, medium and product for identifying the oscillation path of a power network, which can accurately detect the oscillation path.

[0005] An embodiment of the present invention provides a method for identifying the oscillation path of a power network, the method comprising: Based on signal decomposition technology, extracting high-frequency oscillation signals from the voltage and current signals sampled from the power network; According to the high-frequency oscillation signals, calculating an array of electromagnetic field energy values within the resonance period of different nodes in the power network; Calculating the oscillation degree of different nodes according to the array of electromagnetic field energy values; Determining the oscillation path according to the magnitude order of the oscillation degrees.

[0006] Preferably, based on signal decomposition technology, extracting high-frequency oscillation signals from the voltage and current signals sampled from the power network, includes: Based on signal decomposition technology, decomposing the obtained voltage and current signals to obtain oscillation frequency component signals of different frequencies; Extracting the high-frequency oscillation signals from the oscillation frequency component signals according to a preset screening interval.

[0007] Preferably, according to the high-frequency oscillation signals, calculating an array of electromagnetic field energy values within the resonance period of different nodes in the power network, includes: Calculating the electromagnetic field energy of different nodes at different moments according to the high-frequency oscillation signals by using a preset electromagnetic field energy calculation model; Taking a preset resonance duration as the statistical period, and statistically calculating the maximum value of the electromagnetic field energy within different periods of different nodes to obtain the array of electromagnetic field energy values.

[0008] Preferably, the electromagnetic field energy calculation model is ; where W is the electromagnetic field energy of the calculated node, u and i are the branch voltage and branch current measured in the power network respectively, and L and C are the branch inductance and branch capacitance in the power network respectively.

[0009] Preferably, calculating the oscillation degree of different nodes according to the electromagnetic field energy value array includes: Taking the ratio of the mean value of the electromagnetic field energy value array of different nodes in different periods to the maximum value in the electromagnetic field energy value array in different periods as the oscillation degree of this node.

[0010] Preferably, determining the oscillation path according to the magnitude order of the oscillation degree includes; According to the magnitude relationship between a preset reference value and the oscillation degrees of different nodes, arranging the oscillation degrees of different nodes on both sides of the reference value to form an array; Using a recursive algorithm to sort the arrays respectively based on the position of the reference value to obtain an ordered array; Connecting the corresponding node paths according to the order of the ordered array to obtain a connected graph with an energy periodically interacting distribution; Determining the oscillation path according to the connected graph.

[0011] An embodiment of the present invention further provides a power network oscillation path identification device, and the device includes: A decomposition module, configured to extract high-frequency oscillation signals in the voltage and current signals sampled from the power network based on signal decomposition technology; An energy module, configured to calculate the electromagnetic field energy value array of different nodes in the resonance period of the power network according to the high-frequency oscillation signals; An oscillation module, configured to calculate the oscillation degree of different nodes according to the electromagnetic field energy value array; A path module, configured to determine the oscillation path according to the magnitude order of the oscillation degree.

[0012] An embodiment of the present invention further provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the power network oscillation path identification method as described in any one of the above embodiments.

[0013] An embodiment of the present invention further provides a computer-readable storage medium, and the computer-readable storage medium includes a stored computer program. Wherein, when the computer program runs, it controls the device where the computer-readable storage medium is located to execute the power network oscillation path identification method as described in any one of the above embodiments.

[0014] An embodiment of the present invention also provides a computer program product, including a computer program / instructions, which, when executed by a processor, implement the steps of any of the above-mentioned methods.

[0015] The power network oscillation path identification method, device, equipment, medium and product provided by the present invention extract high-frequency oscillation signals in the voltage and current signals sampled from the power network based on signal decomposition technology; calculate an array of electromagnetic field energy values within the resonance periods of different nodes in the power network according to the high-frequency oscillation signals; calculate the oscillation degrees of different nodes according to the array of electromagnetic field energy values; and determine the oscillation path according to the magnitude order of the oscillation degrees. This solution can accurately detect the oscillation path. Description of the Drawings

[0016] Figure 1 is a schematic flowchart of a power network oscillation path identification method provided by an embodiment of the present invention; Figure 2 is a schematic diagram of signal decomposition provided by an embodiment of the present invention; Figure 3 is a schematic structural diagram of a power network oscillation path identification device provided by an embodiment of the present invention; Figure 4 is a schematic structural diagram of a terminal device provided by an embodiment of the present invention. Detailed Embodiments

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] See Figure 1 , which is a schematic flowchart of a power network oscillation path identification method provided by an embodiment of the present invention. The method includes steps S1 to S4: Step S1: Based on signal decomposition technology, extract high-frequency oscillation signals in the voltage and current signals sampled from the power network; Step S2: Calculate an array of electromagnetic field energy values within the resonance periods of different nodes in the power network according to the high-frequency oscillation signals; Step S3: Calculate the oscillation degrees of different nodes according to the array of electromagnetic field energy values; Step S4: Determine the oscillation path according to the magnitude order of the oscillation degrees.

[0019] When this embodiment is specifically implemented, based on the signal decomposition technology, the high-frequency oscillation components of the sampled voltage and current signals are extracted and parameter-identified, and the high-frequency oscillation components to be analyzed are selected; According to the high-frequency oscillation signal, the electromagnetic field energy value of the network is calculated based on the electromagnetic field energy calculation method, and an electromagnetic field energy value array within the resonance period of different nodes in the power network is obtained; It should be noted that the calculated electromagnetic field energy value can be the electric field energy value or the magnetic field energy value.

[0020] Calculate the oscillation degree of different nodes according to the electromagnetic field energy value array; Determine the oscillation path according to the magnitude order of the oscillation degree.

[0021] The oscillation path exploration and traceability scheme for the electric and magnetic field energy provided by this application first extracts and parameter-identifies the high-frequency oscillation signal based on the signal decomposition technology according to the superposition equivalent principle of the circuit, and then calculates the electromagnetic field energy value of the network based on the electromagnetic field energy calculation method. From the perspective of the dominant energy interaction path, the broadband resonance oscillation path is dynamically identified. The scheme of this application can accurately detect the oscillation path, reflect the interaction relationship of the reactive power in the network and the occurrence and development process of the oscillation, identify the oscillation center and the key oscillation path of the network, and trace the oscillation at the same time, providing new ideas and references for the exploration and traceability of the oscillation path of the broadband resonance in the new power system, overcoming the problems of difficult measurement and positioning of the broadband oscillation, and improving the accuracy of oscillation path identification.

[0022] In another embodiment provided by the present invention, step S1 specifically includes the following steps: Based on the signal decomposition technology, extract and parameter-identify the high-frequency oscillation components of the sampled voltage and current signals; See Figure 2 , which is the signal decomposition schematic diagram provided by the embodiment of the present invention. The figure shows the amplitudes of each modal component at different times, as well as the time-domain image, and shows the waveforms of different oscillation components.

[0023] Extract the high-frequency oscillation signal from the oscillation frequency component signal according to a preset screening interval. That is, select the high-frequency oscillation components to be analyzed according to the set threshold determined by the screening interval to obtain oscillation frequency component signals of different frequencies; It should be noted that by selecting the threshold through the screening interval, the high-frequency oscillation components to be analyzed are determined, and there are two threshold selection schemes: Based on the characteristic that the noise signal has independent and identical distribution, set the threshold according to the existing standard as the mean square deviation of the noise signal multiplied by the natural logarithm of the signal length.

[0024] Customize the threshold according to the user's needs: The user is allowed to input one or more thresholds. These thresholds can be: Fixed threshold: A fixed value set by the user based on experience or prior knowledge. Dynamic threshold: The user can dynamically set the threshold according to specific features (such as peaks and valleys) on the spectrogram.

[0025] It should be noted that the signal decomposition technology is one of the harmonic analysis technologies such as filter extraction, wavelet transform, Hilbert transform, Hilbert-Huang transform, Fourier transform, fast Fourier transform, empirical mode decomposition, variational mode decomposition, rotational invariance technique, etc., as well as the corresponding improved algorithms and combined algorithms of each technology.

[0026] In another embodiment provided by the present invention, the process of step S2 specifically includes: Calculate the electromagnetic field energy at different nodes and different moments according to the high-frequency oscillation signal by using a preset electromagnetic field energy calculation model; According to the calculation formula of the electromagnetic field energy, calculate the electric / magnetic field energy of each branch in a cycle with each resonance period T h as the cycle, and for the convenience of calculation, take the maximum value of the energy of each resonance period as the electric / magnetic field energy array of each period .

[0027] In another embodiment provided by the present invention, the electromagnetic field energy calculation model is ; where W is the electromagnetic field energy of the calculated node, u and i are the branch voltage and branch current measured in the power network respectively, L and C are the branch inductance and branch capacitance in the power network respectively, and the resistance is ignored.

[0028] At this time, the electromagnetic field energy calculation model is essentially the electric / magnetic field energy.

[0029] In another embodiment provided by the present invention, the process of step S3 for calculating the oscillation degree specifically includes the following steps: Determine the mean value of the electromagnetic field energy values and the maximum value of the electromagnetic field energy values according to the electromagnetic field energy values in different periods in the electromagnetic field energy value array of different nodes.

[0030] Take the ratio of the mean value of the electromagnetic field energy values of different nodes to the maximum value of the electromagnetic field energy values as the oscillation degree of this node.

[0031] In another embodiment provided by the present invention, step S4 specifically includes the following steps: Divide the oscillation degrees of different nodes into a left array and a right array according to the magnitude relationship between the preset reference value and the oscillation degrees of different nodes; Taking the reference value as the standard, the array is divided into two parts: all elements smaller than the reference value are moved to the right of the reference value, and all elements larger than the reference value are moved to the left of the reference value.

[0032] After the partitioning operation, the reference value will be in the final position of the array, that is, all elements to the left of the reference value are not greater than the reference value, and all elements to the right of the reference value are not less than the reference value, forming an array; Based on the position of the reference value, a recursive algorithm is used to sort the array respectively. The quick sort is recursively performed on the sub-arrays to the left and right of the reference value. Since the reference value is already in the correct position, there is no need to sort the reference value again during the recursive sorting.

[0033] After the recursion ends, the entire array will become an ordered array.

[0034] Connect the corresponding node paths according to the order of the ordered array to obtain a connected graph with an energy periodic interaction distribution; Determine the oscillation path according to the connected graph, that is, determine the oscillation path in sequence according to the positions of different nodes in the array in the connected graph.

[0035] An embodiment of the present invention also provides a power network oscillation path recognition device. Refer to Figure 3 , which is a schematic structural diagram of the power network oscillation path recognition device provided by the embodiment of the present invention. The device includes: A decomposition module, configured to extract high-frequency oscillation signals in the voltage and current signals sampled from the power network based on signal decomposition technology; An energy module, configured to calculate an array of electromagnetic field energy values within the resonance periods of different nodes in the power network according to the high-frequency oscillation signals; An oscillation module, configured to calculate the oscillation degrees of different nodes according to the array of electromagnetic field energy values; A path module, configured to determine the oscillation path according to the magnitude order of the oscillation degrees.

[0036] It should be noted that the power network oscillation path recognition device provided by the embodiment of the present invention can execute the power network oscillation path recognition method described in any of the above embodiments. The specific functions of the power network oscillation path recognition device will not be elaborated here.

[0037] Refer to Figure 4 , which is a schematic structural diagram of a terminal device provided by an embodiment of the present invention. The terminal device in this embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor, such as a power network oscillation path recognition program. When the processor executes the computer program, it implements the steps in each of the above embodiments of the power network oscillation path recognition method, such asFigure 1 Steps S1 to S4 shown. Or when the processor executes the computer program, it implements the functions of each module in the above device embodiments.

[0038] Exemplarily, the computer program can be divided into one or more modules / units, and the one or more modules / units are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units can be a series of computer program instruction segments capable of completing functions, and these instruction segments are used to describe the execution process of the computer program in the terminal device. For example, the computer program can be divided into various modules, and the specific functions of each module will not be elaborated again.

[0039] The terminal device can be a computing device such as a desktop computer, a notebook, a palm computer, and a cloud server. The terminal device may include, but is not limited to, a processor and a memory. Those skilled in the art can understand that the schematic diagram is only an example of the terminal device and does not constitute a limitation on the terminal device. It may include more or fewer components than shown, or combine some components, or different components. For example, the terminal device may further include input / output devices, network access devices, a bus, etc.

[0040] The so-called processor may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The processor is the control center of the terminal device and connects various parts of the entire terminal device through various interfaces and lines.

[0041] The memory can be used to store the computer programs and / or modules. By running or executing the computer programs and / or modules stored in the memory, and invoking the data stored in the memory, the processor realizes various functions of the terminal device. The memory mainly includes a program storage area and a data storage area. Among them, the program storage area can store an operating system, application programs required for at least one function (such as a sound playback function, an image playback function, etc.); the data storage area can store data created according to the use of the mobile phone (such as audio data, phone book, etc.). In addition, the memory can include high-speed random access memory, and can also include non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one magnetic disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0042] Among them, if the modules / units integrated in the terminal device are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on such an understanding, to implement all or part of the processes in the above-mentioned embodiment methods of the present invention, it can also be completed by instructing relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above-mentioned various method embodiments can be realized. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, an executable file, or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a mobile hard disk, a magnetic disk, an optical disc, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunications signal, and a software distribution medium, etc.

[0043] The embodiment of the present invention also provides a computer program product, including a computer program / instructions. When the computer program / instructions are executed by a processor, the steps of the method implemented by the functional network element in the above-mentioned embodiment are realized.

[0044] The computer program product provided in this embodiment can execute all the steps and functions of the sensitive data ciphertext fuzzy query method provided in any of the above-mentioned embodiments. The specific functions of this product will not be elaborated here.

[0045] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications are also regarded as the protection scope of the present invention.

Claims

1. A method for identifying an oscillation path of a power network, characterized in that: The method comprises: Based on signal decomposition technology, high-frequency oscillation signals are extracted from the voltage and current signals sampled from the power network; Calculating an array of electromagnetic field energy values ​​within a resonance period of different nodes in the power network according to the high-frequency oscillation signal; Calculating the oscillation degree of different nodes according to the electromagnetic field energy value array; The oscillation path is determined according to the order of magnitude of the oscillation degree.

2. The method for identifying an oscillation path of a power network according to claim 1, characterized in that: Based on signal decomposition technology, high-frequency oscillation signals are extracted from the voltage and current signals sampled from the power network, including: Based on the signal decomposition technology, the acquired voltage and current signals are decomposed to obtain oscillation frequency component signals of different frequencies; The high-frequency oscillation signal is extracted from the oscillation frequency component signal according to a preset screening interval.

3. The method for identifying an oscillation path of a power network according to claim 1, characterized in that: Calculating an array of electromagnetic field energy values ​​within a resonance period of different nodes in the power network according to the high-frequency oscillation signal includes: Calculating the electromagnetic field energy at different nodes at different times using a preset electromagnetic field energy calculation model according to the high-frequency oscillation signal; The preset resonance duration is used as the statistical period, and the maximum values ​​of the electromagnetic field energy in different periods of different nodes are counted to obtain the electromagnetic field energy value array.

4. The method for identifying an oscillation path of a power network according to claim 3, characterized in that: The electromagnetic field energy calculation model is: ; Wherein, W is the calculated electromagnetic field energy of the node, u and i are the branch voltage and branch current measured in the power network, respectively, and L and C are the branch inductance and branch capacitance in the power network, respectively.

5. The method for identifying an oscillation path of a power network according to claim 1, characterized in that: Calculating the oscillation degree of different nodes according to the electromagnetic field energy value array includes: The ratio of the mean value of the electromagnetic field energy value array of different nodes in different periods to the maximum value in the electromagnetic field energy value array of different periods is taken as the oscillation degree of the node.

6. The method for identifying an oscillation path of a power network according to claim 1, characterized in that: Determining the oscillation path according to the magnitude order of the oscillation degree includes: According to the relationship between the preset reference value and the oscillation degree of different nodes, the oscillation degrees of different nodes are arranged on both sides of the reference value to form an array; Based on the positions of the reference values, the arrays are sorted using a recursive algorithm to obtain an ordered array; Connecting corresponding node paths according to the sequence of the ordered array to obtain a connectivity graph of periodic interactive distribution of energy; The oscillation path is determined based on the connectivity graph.

7. A device for identifying an oscillation path of a power network, characterized in that: The device comprises: A decomposition module, used for extracting high-frequency oscillation signals from voltage and current signals sampled from the power network based on signal decomposition technology; An energy module, used to calculate an array of electromagnetic field energy values ​​within a resonance period of different nodes in the power network according to the high-frequency oscillation signal; An oscillation module, used for calculating the oscillation degree of different nodes according to the electromagnetic field energy value array; A path module is used to determine the oscillation path according to the order of magnitude of the oscillation degree.

8. A terminal device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the method for identifying an oscillation path of an electric power network according to any one of claims 1 to 6 is implemented.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the power network oscillation path identification method according to any one of claims 1 to 6.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

Images