CN117277350A - Impedance calculation, power grid stability analysis method, storage medium and terminal equipment - Google Patents
Impedance calculation, power grid stability analysis method, storage medium and terminal equipment Download PDFInfo
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- H—ELECTRICITY
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Abstract
The invention relates to an impedance calculation and power grid stability analysis method, a storage medium and terminal equipment, comprising the following steps: constructing an impedance calculation model, comprising: an impedance calculation unit for calculating impedance under each disturbance type and response type; according to the actual situation of the scene, a certain type of disturbance signal is input into the tested equipment, and a certain type of response signal at the port is collected; according to the types of the disturbance signals and the response signals, selecting an impedance calculation unit which accords with the actual situation of the scene from an impedance calculation model; extracting voltage and current data with corresponding frequency from the injected disturbance signal and the acquired response signal according to the frequency of the impedance to be calculated and the selected impedance calculation unit; according to the voltage and current data of the corresponding frequency and the selected impedance calculating unit, calculating the impedance to be calculated of each frequency. The disturbance injection, response signal acquisition and impedance calculation units of the system all accord with scene reality, can be flexibly adjusted according to the actual scene of a power grid and the actual requirements of equipment to be measured, and has stronger universality.
Description
Technical Field
The invention relates to the field of power grid simulation, in particular to a multi-scenario impedance calculation method and a stability analysis method.
Background
With the rapid development of renewable energy sources and power electronic equipment in a power grid, the novel power system taking new energy sources as a main body has increasingly remarkable small disturbance instability problems caused by wide-frequency oscillation (the oscillation of the frequency in the power grid ranging from a few tenths of hertz to thousands of hertz can cause unstable, interference, noise and the like, and reasonable design and adjustment are required), so that the reliable absorption of the new energy sources and the safe and stable operation of the novel power system are seriously affected. In the novel power system broadband oscillation calculation analysis method, the impedance analysis method has the advantages of simplicity, convenience, definite physical meaning, strong engineering practicability and the like, and the tested equipment can be regarded as a black box under the condition that the equipment parameters are not easy to obtain, and the impedance characteristics of the tested equipment can be evaluated through a simulation test means.
Many commonly used impedance analysis methods at present can be used for carrying out impedance modeling and analyzing stability aiming at specific scenes, and are simple and convenient to use. However, the method is poor in universality, and because the impedance modeling and stability analysis method is preset according to a specific application scene, when the field environment is not completely consistent with the preset scene and the use scene changes, the modeling and stability analysis effect is greatly limited, and a certain deviation may exist in the analysis result.
Therefore, how to improve the performance of the optical fiber is a technical problem to be solved in the field.
Disclosure of Invention
In order to solve the above technical problems, the present invention provides a multi-scenario impedance calculation method, including:
s1: constructing an impedance calculation model, comprising: an impedance calculation unit for calculating impedance under each disturbance type and response type;
s2: according to the actual situation of the scene, a certain type of disturbance signal is input into the tested equipment, and a certain type of response signal at the port is collected;
s3: according to the types of the disturbance signals and the response signals, selecting an impedance calculation unit which accords with the actual situation of the scene from an impedance calculation model;
s4: extracting voltage and current data with corresponding frequency from the injected disturbance signal and the acquired response signal according to the frequency of the impedance to be calculated and the selected impedance calculation unit;
s5: according to the voltage and current data of the corresponding frequency and the selected impedance calculating unit, calculating the impedance to be calculated of each frequency.
Further, the disturbance type and the response type include: voltage positive sequence disturbance and current positive sequence response; voltage positive sequence disturbance and current negative sequence response; voltage positive sequence disturbance and current direct current response; voltage negative sequence disturbance and current positive sequence response; voltage negative sequence disturbance and current negative sequence response; voltage negative sequence disturbance and current direct current response; voltage direct current disturbance and current positive sequence response; voltage direct current disturbance and current negative sequence response; voltage direct current disturbance and current direct current response; current positive sequence disturbance and voltage positive sequence response; current positive sequence disturbance and voltage negative sequence response; current positive sequence disturbance and voltage direct current response; current negative sequence disturbance and voltage positive sequence response; current negative sequence disturbance and voltage negative sequence response; current negative sequence disturbance and voltage direct current response; current direct current disturbance and voltage positive sequence response; current direct current disturbance and voltage negative sequence response; current-to-direct current disturbance and voltage-to-direct current response; any one or more of the following.
Further, an impedance calculating unit that calculates an impedance employs formula (1):
wherein a is more than or equal to 1 and less than or equal to A, and a is an integer; a represents the number of impedance calculation units,representing current voltage data; />Representing current data; z is Z a (s) represents the current impedance; l (L) a A first constant coefficient representing an a-th impedance calculating unit; k (k) a A second constant coefficient representing the a-th impedance calculating unit.
Further, positive sequence voltage disturbance, positive sequence current response, l 1 ＝0,k 1 =0, then:
positive sequence voltage disturbance, negative sequence current response, l 2 ＝0,k 2 = 2, then:
negative sequence voltage disturbance, positive sequence current response, l 3 ＝0,k 3 = +2, then:
negative sequence voltage disturbance, negative sequence current response, l 4 ＝0,k 4 =0, then:
positive sequence current disturbance, positive sequence voltage response, l 5 ＝0,k 5 =0, then:
positive sequence current disturbance, negative sequence voltage response, l 6 ＝―2,k 6 =0, then:
negative sequence current disturbance, positive sequence voltage response, l 6 ＝+2,k 6 =0, then:
negative sequence current disturbance, negative sequence voltage response, l 6 ＝0,k 6 =0, then:
wherein Z represents impedance, v represents voltage, i represents current, subscript p represents positive sequence, n represents negative sequence, s represents current calculated frequency, ω 1 Representing the fundamental frequency of the device under test.
On the other hand, the invention also provides a multi-scene power grid stability analysis method, which comprises the following steps:
p1: adopting the steps S1-S5, respectively taking a power end and a load end as tested equipment, and calculating the impedance of each frequency of the power end and the impedance of each frequency of the load end;
p2: constructing a characteristic curve of source load impedance according to the impedance of each frequency of the power supply end and the impedance of each frequency of the load end;
p3: and according to the characteristic curve and stability analysis and judgment of the source load impedance, evaluating the stability of the current power grid.
Further, the method comprises the steps of: in the step P2, according to the impedance information of each frequency of the power supply end, namely source impedance data; impedance information of each frequency of the load end, namely load impedance data; the source impedance data of the same frequency are divided by the load impedance data on each frequency, the source-to-load impedance ratio is calculated, a plurality of impedance characteristic points are obtained, the real part and the imaginary part of the impedance characteristic points are shown in the figure, then the real part and the imaginary part are connected into a line according to the sequence from the small frequency to the large frequency, and an impedance characteristic curve is drawn.
Further, the stability criteria include: nyquist criterion, MPC criterion, GMPM criterion, opposing Argument criterion, ESAC criterion or a combination of several criteria.
In another aspect, the present invention also provides a computer storage medium storing executable program code; the executable program code is configured to execute any of the above-described multi-scenario impedance calculation methods or any of the above-described grid stability analysis methods.
In another aspect, the present invention further provides a terminal device, including a memory and a processor; the memory stores program code executable by the processor; the program code is used for executing any of the multi-scenario impedance calculation methods or any of the grid stability analysis methods.
The invention provides an impedance calculation and power grid stability analysis method, a storage medium and a terminal device, wherein an impedance calculation model comprising a plurality of impedance calculation units under each disturbance type and response type is firstly constructed, then according to actual conditions, what the disturbance type response type is, which is concerned by the scene, is considered, disturbance signals of a certain type are input into tested equipment, and response signals of a certain type at a port are collected so as to adjust according to the disturbance type and the response type, and the impedance calculation units are flexibly selected; determining the frequency of the impedance to be calculated which is concerned according to the actual scene, and extracting voltage and current data of the corresponding frequency from the injected disturbance signal and the acquired response signal according to the frequency of the impedance to be calculated and the selected impedance calculating unit; and then according to the selected impedance calculating unit, calculating the impedance to be calculated of each frequency. The whole disturbance injection process accords with the scene reality, the response signal focused and collected by the disturbance injection process accords with the scene reality, and the impedance calculation unit selected in the impedance calculation model accords with the scene reality, so that the disturbance injection process can adapt to various industries and application scenes, can be flexibly adjusted according to the actual scene of a power grid and the actual requirements of equipment to be measured, can meet the impedance scanning of most power electronic equipment and new energy station clusters, and can meet the subsequent impedance stability analysis requirements, and the disturbance injection process is simpler and more convenient to use and has stronger universality.
Drawings
FIG. 1 is a flow chart of an embodiment of a multi-scenario impedance calculation method of the present invention;
fig. 2 is a schematic diagram of a grid stability analysis.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
It should be noted that, in the embodiment of the present invention, directional indications such as up, down, left, right, front, and rear … … are referred to, and the directional indications are merely used to explain the relative positional relationship, movement conditions, and the like between the components in a specific posture, and if the specific posture is changed, the directional indications are correspondingly changed. In addition, if there are descriptions of "first, second", "S1, S2", "step one, step two", etc. in the embodiments of the present invention, the descriptions are only for descriptive purposes, and are not to be construed as indicating or implying relative importance or implying that the number of technical features indicated or indicating the execution sequence of the method, etc. it will be understood by those skilled in the art that all matters in the technical concept of the present invention are included in the scope of this invention without departing from the gist of the present invention.
As shown in fig. 1, the present invention provides a multi-scenario impedance calculation method, including:
s1: constructing an impedance calculation model, comprising: an impedance calculation unit for calculating impedance under each disturbance type and response type;
specifically, the specific types and the number of each disturbance type and each response type can be set arbitrarily according to the requirements of equipment to be tested such as power sources, loads and the like in a power grid, namely the current scene; alternative but not limited to include: the voltage is responsive to the current disturbance or the voltage is responsive to the current disturbance; each disturbance or response, in turn, includes positive sequence, negative sequence, direct current, etc., optionally but not limited to 18 cases depending on the cross-matching of the disturbance type and the response type: voltage positive sequence disturbance and current positive sequence response; voltage positive sequence disturbance and current negative sequence response; voltage positive sequence disturbance and current direct current response; voltage negative sequence disturbance and current positive sequence response; voltage negative sequence disturbance and current negative sequence response; voltage negative sequence disturbance and current direct current response; voltage direct current disturbance and current positive sequence response; voltage direct current disturbance and current negative sequence response; voltage direct current disturbance and current direct current response; current positive sequence disturbance and voltage positive sequence response; current positive sequence disturbance and voltage negative sequence response; current positive sequence disturbance and voltage direct current response; current negative sequence disturbance and voltage positive sequence response; current negative sequence disturbance and voltage negative sequence response; current negative sequence disturbance and voltage direct current response; current direct current disturbance and voltage positive sequence response; current direct current disturbance and voltage negative sequence response; current-to-direct current disturbance and voltage-to-direct current response; any one or more of the following.
More specifically, the impedance calculation units that calculate the impedance are constructed separately for the 18 cases, optionally but not exclusively, to obtain impedance calculation models for the respective disturbance types and response types.
More specifically, the impedance calculation model is optionally, but not limited to, storing each type and each impedance calculation unit in a one-to-one mapping manner for later recall.
More specifically, the impedance calculation unit for the 18 cases is optionally but not limited to a different formula, as shown in formula (1).
Wherein a is more than or equal to 1 and less than or equal to A, and a is an integer; a represents the number of impedance calculation units,representing current voltage data; />Representing current data; z is Z a (s) represents the current impedance; l (L) a A first constant coefficient representing an a-th impedance calculating unit; k (k) a A second constant coefficient representing the a-th impedance calculating unit.
More specifically, the impedance calculation unit for the 18 cases,k a 、l a there are values thereof, and as shown in formulas (2) to (9), 8 types of formulas for calculating impedance are exemplified.
Positive sequence voltage disturbance, positive sequence current response, l 1 ＝0,k 1 =0, then:
positive sequence voltage disturbance, negative sequence current response, l 2 ＝0,k 2 = 2, then:
negative sequence voltage disturbance, positive sequence current response, l 3 ＝0,k 3 = +2, then:
negative sequence voltage disturbance, negative sequence current response, l 4 ＝0,k 4 =0, then:
positive sequence current disturbance, positive sequence voltage response, l 5 ＝0,k 5 =0, then:
positive sequence current disturbance, negative sequence voltage response, l 6 ＝―2,k 6 =0, then:
negative sequence current disturbance, positive sequence voltage response, l 6 ＝+2,k 6 =0, then:
negative sequence current disturbance, negative sequence voltage response, l 6 ＝0,k 6 =0, then:
wherein Z represents impedance, v represents voltage, i represents current, subscript p represents positive sequence, n represents negative sequence, s represents current calculated frequency, ω 1 Representing the fundamental frequency of the device under test.
S2: according to the actual situation of the scene, a certain type of disturbance signal is input into the tested equipment, and a certain type of response signal at the port is collected;
specifically, the device type and the disturbance injection type are selected according to the actual situation of the current scene of the power grid, such as the actual situation of the tested device including a power source, a load and the like, a certain type of disturbance signal, such as positive sequence voltage disturbance, is selectively injected into the tested device, and a certain type of response signal, such as positive sequence current response, at a port is acquired. Specifically, the disturbance signal injection mode comprises voltage disturbance current response and current disturbance voltage response; the disturbance signal and the response signal respectively comprise positive sequence, negative sequence and direct current.
S3: according to the types of the disturbance signals and the response signals, selecting an impedance calculation unit which accords with the actual situation of the scene from an impedance calculation model;
specifically, according to the above example, the types of the disturbance signal and the response signal are respectively: and (3) selecting the formula (2) as an impedance calculation unit which accords with the actual situation of a scene in the impedance calculation model if the positive sequence voltage disturbance and the positive sequence current respond.
S4: extracting voltage and current data with corresponding frequency from the injected disturbance signal and the acquired response signal according to the frequency of the impedance to be calculated and the selected impedance calculation unit;
according to the current actual scene, comparing the frequency of the concerned impedance to be calculated, if the impedance to be calculated has a frequency of 200Hz and a fundamental frequency of 50, and taking positive sequence voltage disturbance and positive sequence current response as examples, selecting the formula (2) as a selected impedance calculation unit, then determining that extraction is needed: positive sequence voltage with frequency of 200Hz and positive sequence current with frequency of 200 Hz;
as another example, if the positive sequence voltage disturbance and the negative sequence current response are taken as examples, the selected impedance calculation unit is selected as the formula (3), and it can be determined that the extraction is required: positive sequence voltage with frequency of 200Hz and negative sequence current with frequency of 100 Hz;
as another example, if the negative sequence voltage disturbance and the negative sequence current response are taken as examples, the selected impedance calculation unit is selected as the formula (5), and it can be determined that the extraction is required: a negative sequence voltage with a frequency of 200Hz and a negative sequence current with a frequency of 200 Hz;
as another example, if the negative sequence voltage disturbance and the positive sequence current response are selected as the selected impedance calculation unit in the formula (4), it may be determined that the extraction is required: negative sequence voltage with frequency of 200Hz and positive sequence current with frequency of 300 Hz.
Similarly, the frequencies of the concerned impedances to be calculated can be compared according to the current practical scene, and according to the selected impedance calculating unit, voltage and current data with corresponding frequencies can be extracted from the injected disturbance signals and the acquired response signals by adopting Fourier transformation, namely: when the voltage is disturbed, the disturbance signal is injected as voltage data, and the acquisition response signal is current data; when the current is disturbed, the disturbance signal is the current data, and the collected response signal is the voltage data.
Preferably, when extracting voltage and current data of a corresponding frequency, a proper filtering algorithm and a proper transformation algorithm are selected according to the current requirement to process the voltage and current data, such as filtering by using a rectangular window and a Hanning window in general, when the frequency is insensitive and the precision requirement is high, filtering is performed by using a flat-top window, and then the voltage and current data of the corresponding frequency is converted into a frequency domain after filtering, so that the voltage and current data of the corresponding frequency is extracted.
S5: according to the voltage and current data of the corresponding frequency and the selected impedance calculating unit, calculating the impedance to be calculated of each frequency.
Specifically, the voltage and current data of the corresponding frequency determined in step S4 is input into the impedance calculating unit selected in step S3 to calculate the impedance to be calculated of each frequency, preferably, in the above formula (1), the corresponding formula is selected, and the voltage and current data of the corresponding frequency is input into the formula to calculate the impedance to be calculated of each frequency.
More specifically, taking the positive sequence voltage disturbance and the negative sequence current response as examples, 200Hz impedance is calculated, according to the formula (3), it can be determined that the positive sequence voltage of 200Hz and the negative sequence current of 100Hz are collected first, and then according to the formula (3), the amplitude of the positive sequence voltage of 200Hz is divided by the amplitude of the negative sequence current of 100Hz to obtain the amplitude of the impedance to be calculated with the frequency of 200 Hz; the phase of the 200Hz impedance to be calculated is obtained by subtracting the phase of the 100Hz negative sequence current from the phase of the 200Hz positive sequence voltage. After the amplitude and the phase of the impedance are obtained, the amplitude is multiplied by the cosine value of the phase to obtain the real part of the impedance; the amplitude is multiplied by the sine of the phase to obtain the imaginary part of the impedance. And then calculating the other frequencies in turn to obtain the impedance to be calculated of each frequency of the equipment to be measured.
In the embodiment, the multi-scene impedance calculation method of the invention is provided, firstly, an impedance calculation model comprising a plurality of impedance calculation units under each disturbance type and response type is constructed, then according to actual conditions, what the disturbance type response type is, which is concerned by the scene, is seen, disturbance signals of a certain type are input into the tested equipment, and response signals of a certain type at a port are collected, so that the impedance calculation units are adjusted according to the disturbance type and the response type, and the impedance calculation units are flexibly selected; determining the frequency of the impedance to be calculated which is concerned according to the actual scene, and extracting voltage and current data of the corresponding frequency from the injected disturbance signal and the acquired response signal according to the frequency of the impedance to be calculated and the selected impedance calculating unit; and then according to the selected impedance calculating unit, calculating the impedance to be calculated of each frequency. The whole disturbance injection process accords with the scene reality, the response signal focused and collected by the disturbance injection process accords with the scene reality, and the impedance calculation unit selected in the impedance calculation model accords with the scene reality, so that the disturbance injection process can adapt to various industries and application scenes, can be flexibly adjusted according to the actual scene of a power grid and the actual requirements of equipment to be measured, can meet the impedance scanning of most power electronic equipment and new energy station clusters, and can meet the subsequent impedance stability analysis requirements, and the disturbance injection process is simpler and more convenient to use and has stronger universality.
On the other hand, the invention also provides a multi-scene power grid stability analysis method, which comprises the following steps:
p1: and adopting the steps S1-S5, respectively taking a power end and a load end as tested equipment, and calculating the impedance of each frequency of the power end and the impedance of each frequency of the load end.
Specifically, steps S1-S5 are adopted optionally but not only according to the actual situation of a power supply end in a power grid, a certain type of disturbance signal is injected, and a certain type of response signal is collected so as to calculate the impedance information of each frequency of the disturbance signal; for each load, steps S1-S5 can be adopted according to the actual condition of each load, a certain type of disturbance signal is injected, and a certain type of response signal is collected, so that impedance information of each frequency of each load can be calculated.
P2: and constructing a characteristic curve of the source load impedance according to the impedance of each frequency of the power supply end and the impedance of each frequency of the load end.
Specifically, according to impedance information of each frequency of the power supply end, namely source impedance data; impedance information of each frequency of the load end, namely load impedance data; the source-to-charge impedance ratio is calculated by dividing the source impedance data with the same frequency by the charge impedance data at each frequency to obtain a plurality of impedance characteristic points, the real parts and the imaginary parts of the impedance characteristic points are shown in the figure, and then the real parts and the imaginary parts are connected into lines according to the sequence from the small frequency to the large frequency, so that an impedance characteristic curve is obtained by drawing, and the middle curve of the graph is shown in fig. 2.
P3: and according to the characteristic curve and stability analysis and judgment of the source load impedance, evaluating the stability of the current power grid.
Specifically, a baud or nyquist diagram is constructed, optionally but not limited to, according to selected stability criteria, optionally but not limited to including nyquist criteria, MPC criteria, GMPM criteria, opposing Argument criteria, ESAC criteria, or a combination of several criteria, etc., and a stability margin or rendering forbidden region is calculated in the diagram. When the stability margin is negative or the impedance characteristic enters the forbidden region, the system is unstable. As shown in fig. 2, if criteria 1-Opposing Argument are used, the forbidden zone is a vertical line and its left region, and the result is an unstable state because the impedance characteristic curve enters the forbidden zone. If the criterion 2-MPC is used, the forbidden region is a circular region, and the impedance characteristic curve does not enter the forbidden region, so that the result is a stable state. Furthermore, if the impedance characteristic is tangential to the forbidden edge, it is a critical steady state. The risk frequency is typically the frequency of the unstable point in an unstable state. The stability margin is the degree of the unstable state, the larger the margin is, the lower the instability is, and the better the current state of the power grid is.
Step 5 can qualitatively display the current system steady state, and quantitatively display the risk frequency and the stability margin of the current system. When broadband oscillation exists in the power grid, corresponding information such as oscillation frequency, impedance and the like is displayed.
The invention has the beneficial effects that:
1. the method is suitable for actual scenes, and can select a proper scheme to extract voltage and current data and calculate impedance information according to the type of equipment and the injection mode of disturbance signals, so that the disturbance injection mode can be flexibly selected on the premise of not affecting the operation of the equipment, and the universality is stronger;
2. preferably, a plurality of different criteria are built in, such as Nyquist criteria, MPC criteria, GMPM criteria, opposing Argument criteria, ESAC criteria and the like, and a user can select different criteria according to the topology condition of a power grid in actual application;
3. the method is not limited in use, can be suitable for different application scenes and industry standards such as wind power, photovoltaic power generation, energy storage, reactive compensation, flexible direct current transmission, solid-state transformers, uninterruptible power supplies and the like, can be suitable for impedance stability analysis under different working conditions, and can meet numerous requirements of different users;
4. the impedance calculation mode is suitable for scene requirements, the calculation result is more accurate and unlimited, the stable state, margin and oscillation information of the power grid can be calculated qualitatively and quantitatively, and the stable state, margin and oscillation information can be displayed in modes of a Boud chart, a Nyquist chart and the like.
On the other hand, the impedance calculation method and the power grid stability analysis method based on multiple scenes also provide a system for impedance calculation and power grid stability analysis, the combination and technical effects of the technical characteristics are not repeated here, and the system can flexibly adjust the impedance calculation mode and the stability analysis criterion according to the power grid condition, so that the system can be suitable for various industries and application scenes.
In another aspect, the present invention also provides a computer storage medium storing executable program code; the executable program code is used for executing any multi-scenario impedance calculation method or grid stability analysis method.
In another aspect, the present invention further provides a terminal device, including a memory and a processor; the memory stores program code executable by the processor; the program code is used for executing any multi-scenario impedance calculation method or grid stability analysis method.
For example, the program code may be partitioned into one or more modules/units that are stored in the memory and executed by the processor to perform the present invention. The one or more modules/units may be a series of computer program instruction segments capable of performing the specified functions, which instruction segments describe the execution of the program code in the terminal device.
The terminal equipment can be computing equipment such as a desktop computer, a notebook computer, a palm computer, a cloud server and the like. The terminal device may include, but is not limited to, a processor, a memory. Those skilled in the art will appreciate that the terminal devices may also include input-output devices, network access devices, buses, and the like.
The processor may be a central processing unit (Central Processing Unit, CPU), but may also be other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), off-the-shelf programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The storage may be an internal storage unit of the terminal device, such as a hard disk or a memory. The memory may also be an external storage device of the terminal device, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card) or the like, which are provided on the terminal device. Further, the memory may also include both an internal storage unit of the terminal device and an external storage device. The memory is used for storing the program codes and other programs and data required by the terminal equipment. The memory may also be used to temporarily store data that has been output or is to be output.
The above multi-scenario power grid stability analysis method, computer storage medium and terminal device are created based on the above multi-scenario impedance calculation method, and the technical effects and advantages thereof are not repeated herein, and each technical feature of the above embodiment may be arbitrarily combined, so that the description is concise, and all possible combinations of each technical feature in the above embodiment are not described, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that variations and modifications can be made by those skilled in the art without departing from the spirit of the invention, which fall within the scope of the invention. The protection scope of the patent of the invention shall be subject to the appended claims.
Claims (9)
1. A multi-scenario impedance calculation method, comprising:
s1: constructing an impedance calculation model, comprising: an impedance calculation unit for calculating impedance under each disturbance type and response type;
s2: according to the actual situation of the scene, a certain type of disturbance signal is input into the tested equipment, and a certain type of response signal at the port is collected;
s3: according to the types of the disturbance signals and the response signals, selecting an impedance calculation unit which accords with the actual situation of the scene from an impedance calculation model;
s4: extracting voltage and current data with corresponding frequency from the injected disturbance signal and the acquired response signal according to the frequency of the impedance to be calculated and the selected impedance calculation unit;
s5: according to the voltage and current data of the corresponding frequency and the selected impedance calculating unit, calculating the impedance to be calculated of each frequency.
2. The multi-scenario impedance calculation method according to claim 1, wherein the disturbance type and the response type include: voltage positive sequence disturbance and current positive sequence response; voltage positive sequence disturbance and current negative sequence response; voltage positive sequence disturbance and current direct current response; voltage negative sequence disturbance and current positive sequence response; voltage negative sequence disturbance and current negative sequence response; voltage negative sequence disturbance and current direct current response; voltage direct current disturbance and current positive sequence response; voltage direct current disturbance and current negative sequence response; voltage direct current disturbance and current direct current response; current positive sequence disturbance and voltage positive sequence response; current positive sequence disturbance and voltage negative sequence response; current positive sequence disturbance and voltage direct current response; current negative sequence disturbance and voltage positive sequence response; current negative sequence disturbance and voltage negative sequence response; current negative sequence disturbance and voltage direct current response; current direct current disturbance and voltage positive sequence response; current direct current disturbance and voltage negative sequence response; current-to-direct current disturbance and voltage-to-direct current response; any one or more of the following.
3. The multi-scenario impedance calculation method according to claim 2, wherein the impedance calculation unit that calculates the impedance uses formula (1):
wherein a is more than or equal to 1 and less than or equal to A, and a is an integer; a represents the number of impedance calculation units,representing current voltage data; />Representing current data; z is Z a (s) represents the current impedance; l (L) a A first constant coefficient representing an a-th impedance calculating unit; k (k) a A second constant coefficient representing the a-th impedance calculating unit.
4. A multi-scenario impedance calculation method according to claim 3, wherein positive sequence voltage perturbation, positive sequence current response, l 1 ＝0,k 1 =0, then:
positive sequence voltage disturbance, negative sequence current response, l 2 ＝0,k 2 = 2, then:
negative sequence voltage disturbance, positive sequence current response, l 3 ＝0,k 3 = +2, then:
negative sequence voltage disturbance, negative sequence current response, l 4 ＝0,k 4 =0, then:
positive sequence current disturbance, positive sequence voltage response, l 5 ＝0,k 5 =0, then:
positive sequence current disturbance, negative sequence voltage response, l 6 ＝―2,k 6 =0, then:
negative sequence current disturbance, positive sequence voltage response, l 6 ＝+2,k 6 =0, then:
negative sequence current disturbance, negative sequence voltage response, l 6 ＝0,k 6 =0, then:
wherein Z represents impedance, v represents voltage, i represents current, subscript p represents positive sequence, n represents negative sequence, s represents current calculated frequency, ω 1 Representing the fundamental frequency of the device under test.
5. A multi-scenario grid stability analysis method, comprising:
p1: adopting the steps S1-S5, respectively taking a power end and a load end as tested equipment, and calculating the impedance of each frequency of the power end and the impedance of each frequency of the load end;
p2: constructing a characteristic curve of source load impedance according to the impedance of each frequency of the power supply end and the impedance of each frequency of the load end;
p3: and according to the characteristic curve and stability analysis and judgment of the source load impedance, evaluating the stability of the current power grid.
6. The grid stability analysis method of claim 5, comprising: in the step P2, according to the impedance information of each frequency of the power supply end, namely source impedance data; impedance information of each frequency of the load end, namely load impedance data; the source impedance data of the same frequency are divided by the load impedance data on each frequency, the source-to-load impedance ratio is calculated, a plurality of impedance characteristic points are obtained, the real part and the imaginary part of the impedance characteristic points are shown in the figure, then the real part and the imaginary part are connected into a line according to the sequence from the small frequency to the large frequency, and an impedance characteristic curve is drawn.
7. The grid stability analysis method of claim 6, wherein the stability criteria include: nyquist criterion, MPC criterion, GMPM criterion, opposing Argument criterion, ESAC criterion or a combination of several criteria.
8. A computer storage medium having executable program code stored therein; the executable program code for performing the multi-scenario impedance calculation method of any one of claims 1-4 or the grid stability analysis method of any one of claims 5-7.
9. A terminal device comprising a memory and a processor; the memory stores program code executable by the processor; the program code is configured to perform the multi-scenario impedance calculation method of any one of claims 1-4 or the grid stability analysis method of any one of claims 5-7.
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