A disturbance frequency grouping parallel impedance analysis method and device

Abstract

The present invention discloses a disturbance frequency grouping parallel impedance analysis method and device, the method comprising: numbering each frequency point in three frequency segmentation point sets according to the first frequency interval, the second frequency interval, and the third frequency interval; grouping each frequency point in the ten-frequency segmentation point set, the hundred-frequency segmentation point set, and the thousand-frequency segmentation point set according to the numbering result and the numbering grouping rule, respectively, to obtain multiple frequency band sub-groups corresponding to each segmentation point set; inputting each frequency band sub-group into the target system in turn, and calculating the voltage disturbance component and the current disturbance component after fast Fourier transformation in the target system according to the frequency band interval and numbering result corresponding to each frequency band sub-group, and selecting the impedance amplitude and phase. By adopting the present invention, the disturbance frequencies are grouped, and the disturbances of the same group are injected simultaneously, so as to realize parallel impedance analysis and improve the accuracy and efficiency of impedance analysis.

Description

Technical Field

[0001] The present invention relates to the field of frequency domain impedance analysis, and in particular to a disturbance frequency grouping parallel impedance analysis method and device. Background Art

[0002] With the continuous development of new energy, the scale and proportion of new energy power generation have increased, and a large number of new energy power generation systems such as photovoltaics and wind power are connected to the power grid, which has an impact on the safety and stability of the power grid. At present, in order to study the impact of new energy power generation systems on the stability of the power grid and ensure the safe and stable operation of the power grid, the mainstream method is to evaluate the impedance characteristics of the system before the new energy power generation system is connected to the grid. Specifically, a small signal voltage disturbance or current disturbance of a certain amplitude and frequency is injected into the grid connection point or the port of the power device of the new energy power generation system, and the ratio between the port voltage after the small signal disturbance is injected and the current response of the corresponding frequency is analyzed, and this ratio is used to describe the small signal dynamic characteristics of the new energy power generation system, that is, the impedance characteristics. The impedance characteristic evaluation is generally carried out by electromagnetic transient simulation, and the main work content includes impedance characteristic evaluation modeling, frequency domain impedance analysis and time domain electromagnetic transient simulation.

[0003] There are three main existing methods of injecting disturbances of different frequencies: the first is multiple injections, each time injecting a disturbance of a different frequency; the second is only injecting once, injecting a disturbance of variable frequency, for example, the frequency of this disturbance gradually increases from 1Hz to 1000Hz; the third is only injecting once, injecting disturbances of all frequencies at once, that is, all disturbances of frequencies of 1Hz, 2Hz, ..., 1000Hz are superimposed together and injected at one time.

[0004] The first and second methods are essentially to inject disturbances with only one frequency within a period of time, and each time the system must be stabilized before entering the next frequency disturbance injection process. Therefore, although it has higher result accuracy than the third method, it is time-consuming and the impedance analysis efficiency is very low. The third method injects full-frequency disturbances at the same time, which can reduce the time consumption of impedance analysis. However, due to the different and obvious differences in the disturbance frequencies, the system may not be stable when extracting the voltage and current disturbance components, or the extracted data length does not meet the impedance analysis requirements, resulting in inaccurate results. In addition, the harmonics generated by two disturbances with too large frequency differences may affect each other, causing instability in the entire system, and the extracted voltage and current disturbance components will also be inaccurate. Summary of the invention

[0005] The embodiment of the present invention provides a disturbance frequency grouping parallel impedance analysis method and device, selects appropriate disturbance frequencies, and groups the disturbance frequencies, and injects disturbances of the same group simultaneously to realize parallel impedance analysis.

[0006] To achieve the above-mentioned purpose, a first aspect of an embodiment of the present application provides a disturbance frequency grouping parallel impedance analysis method, comprising:

[0007] Select frequency points from the disturbance frequency set in the ten-frequency band, the hundred-frequency band, and the thousand-frequency band according to the first frequency interval, the second frequency interval, and the third frequency interval, respectively, and sequentially establish a ten-frequency segment point set, a hundred-frequency segment point set, and a thousand-frequency segment point set; the ten-frequency band refers to 0 Hz to 10 Hz, the hundred-frequency band refers to 10 Hz to 100 Hz, and the thousand-frequency band refers to 100 Hz to 1000 Hz;

[0008] Numbering each frequency point in the ten-frequency segment point set, the one-hundred-frequency segment point set, and the one-thousand-frequency segment point set according to the first frequency interval, the second frequency interval, and the third frequency interval, respectively; the number of each frequency point is the quotient of the frequency value divided by the corresponding frequency interval;

[0009] According to the numbering results and the numbering grouping rules, each frequency point in the ten-frequency segment point set, the one-hundred-frequency segment point set, and the one-thousand-frequency segment point set is grouped respectively to obtain a plurality of frequency band subgroups corresponding to each segment point set;

[0010] The disturbance frequencies of all frequency points in each frequency band subgroup are superimposed together in turn and input into the target system at the same time. According to the frequency band interval and numbering result corresponding to each frequency band subgroup, the voltage disturbance component and current disturbance component after fast Fourier transformation in the target system are calculated and the impedance amplitude and phase are selected.

[0011] In a possible implementation manner of the first aspect, grouping each frequency point in the ten-frequency segment point set, the one-hundred-frequency segment point set, and the one-thousand-frequency segment point set according to the numbering result and the numbering grouping rule to obtain multiple frequency band subgroups corresponding to each segment point set specifically includes:

[0012] In each segment point set, frequency points with prime numbers are selected to be divided into prime subgroups;

[0013] From the remaining frequency points of the segment point set, select the frequency points numbered multiples of 7 and group them into one group;

[0014] From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 5 and group them into one group;

[0015] From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 3 and group them into one group;

[0016] From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 2 and group them into one group.

[0017] In a possible implementation manner of the first aspect, calculating the voltage disturbance component and the current disturbance component after fast Fourier transformation in the target system and selecting the impedance amplitude and phase according to the frequency band interval and numbering result corresponding to each frequency band subgroup specifically includes:

[0018] The frequency base value is set according to the frequency band interval and numbering result corresponding to each frequency band subgroup; the frequency base value is a multiple of the corresponding frequency band interval;

[0019] According to the frequency base value, performing a fast Fourier transform on the voltage disturbance component and the current disturbance component in the target system;

[0020] According to the voltage disturbance component and the current disturbance component after the fast Fourier transformation, the impedance amplitude and phase of the target system under the influence of each frequency point are calculated.

[0021] In a possible implementation manner of the first aspect, the first frequency interval, the second frequency interval, and the third frequency interval are all powers of ten.

[0022] In a possible implementation manner of the first aspect, frequency points greater than 1000 Hz are selected from the disturbance frequency set to establish an additional segmentation point set;

[0023] According to the third frequency interval, numbering each frequency point in the additional segmentation point set;

[0024] The numbered additional segmentation point set is used as a frequency band subgroup corresponding to the thousand-frequency segmentation point set.

[0025] A second aspect of an embodiment of the present application provides a disturbance frequency grouping parallel impedance analysis device, comprising:

[0026] A frequency selection module is used to select frequency points from the disturbance frequency set in accordance with the first frequency interval, the second frequency interval, and the third frequency interval in the ten-frequency band, the hundred-frequency band, and the thousand-frequency band, respectively, to sequentially establish a ten-frequency segmentation point set, a hundred-frequency segmentation point set, and a thousand-frequency segmentation point set; the ten-frequency band refers to 0 Hz to 10 Hz, the hundred-frequency band refers to 10 Hz to 100 Hz, and the thousand-frequency band refers to 100 Hz to 1000 Hz;

[0027] a numbering module, configured to number each frequency point in the ten-frequency segment point set, the hundred-frequency segment point set, and the thousand-frequency segment point set according to the first frequency interval, the second frequency interval, and the third frequency interval, respectively; the number of each frequency point is a quotient of a frequency value divided by a corresponding frequency interval;

[0028] A grouping module, used for grouping each frequency point in the ten-frequency segment point set, the one-hundred-frequency segment point set, and the one-thousand-frequency segment point set according to the numbering result and the numbering grouping rule, to obtain a plurality of frequency band subgroups corresponding to each segment point set;

[0029] The analysis module is used to sequentially superimpose the disturbance frequencies of all frequency points in each frequency band subgroup and input them into the target system at the same time, calculate the voltage disturbance component and current disturbance component after fast Fourier transformation in the target system according to the frequency band interval and numbering result corresponding to each frequency band subgroup, and select the impedance amplitude and phase.

[0030] In a possible implementation manner of the second aspect, the grouping module is specifically configured to:

[0031] In each segment point set, frequency points with prime numbers are selected to be divided into prime subgroups;

[0032] From the remaining frequency points of the segment point set, select the frequency points numbered multiples of 7 and group them into one group;

[0033] From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 5 and group them into one group;

[0034] From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 3 and group them into one group;

[0035] From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 2 and group them into one group.

[0036] In a possible implementation manner of the second aspect, calculating the voltage disturbance component and the current disturbance component after fast Fourier transformation in the target system and selecting the impedance amplitude and phase according to the frequency band interval and numbering result corresponding to each frequency band subgroup specifically includes:

[0037] The frequency base value is set according to the frequency band interval and numbering result corresponding to each frequency band subgroup; the frequency base value is a multiple of the corresponding frequency band interval;

[0038] According to the frequency base value, performing a fast Fourier transform on the voltage disturbance component and the current disturbance component in the target system;

[0039] According to the voltage disturbance component and the current disturbance component after the fast Fourier transformation, the impedance amplitude and phase of the target system under the influence of each frequency point are calculated.

[0040] In a possible implementation manner of the second aspect, the first frequency interval, the second frequency interval, and the third frequency interval are all powers of ten.

[0041] In a possible implementation manner of the second aspect, the frequency selection module is further used to: select frequency points greater than 1000 Hz from the disturbance frequency set to establish an additional segmentation point set;

[0042] The numbering module is further used to number each frequency point in the additional segmentation point set according to the third frequency interval;

[0043] The grouping module is further used to use the numbered additional segmentation point set as a frequency band sub-group corresponding to the thousand-frequency segmentation point set.

[0044] Compared with the prior art, an impedance analysis device with disturbance frequency grouping and parallel operation provided in an embodiment of the present invention can more accurately reflect the system impedance characteristics of the low frequency band by setting the first frequency interval to increase to the frequency point in the low frequency band (within the ten frequency band); and can greatly reduce the time consumption of impedance analysis and improve the efficiency of impedance analysis by reducing the third frequency interval to the frequency point in the high frequency band (thousand frequency band). In addition, the frequency points concentrated in the segmentation points corresponding to the three segments of the ten frequency band, the hundred frequency band, and the thousand frequency band are grouped to obtain a plurality of frequency band sub-groups with a relatively even number of frequency points. The disturbance frequencies in each group are multiples of a certain number (the first frequency interval or the second frequency interval or the third frequency interval), which facilitates the selection of a better frequency base value for Fourier transform. In summary, the embodiment of the present invention takes into account the resolution of the impedance analysis results of the low frequency band and the high frequency band at the same time, making the results more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a flow chart of a disturbance frequency grouping parallel impedance analysis method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] In order to solve the problem of low efficiency of impedance analysis, the existing technology has a parallel impedance analysis method that uses high-performance computers or multi-core parallel processors to inject disturbances of different frequencies into multiple identical impedance models at the same time. However, this method essentially achieves parallelism through hardware performance and does not change the disturbance injection principle of impedance analysis. Its efficiency depends on the performance of the selected parallel hardware, and there are still limitations in cost and implementation.

[0048] See also Figure 1According to a first aspect of an embodiment of the present invention, a disturbance frequency grouping parallel impedance analysis method is provided, comprising:

[0049] S10. Select frequency points from the disturbance frequency set in the ten-frequency band, the hundred-frequency band, and the thousand-frequency band according to the first frequency interval, the second frequency interval, and the third frequency interval, respectively, and establish a ten-frequency segment point set, a hundred-frequency segment point set, and a thousand-frequency segment point set in sequence; the ten-frequency band refers to 0 Hz to 10 Hz, the hundred-frequency band refers to 10 Hz to 100 Hz, and the thousand-frequency band refers to 100 Hz to 1000 Hz.

[0050] S11. Number each frequency point in the ten-frequency segment point set, the one-hundred-frequency segment point set, and the one-thousand-frequency segment point set according to the first frequency interval, the second frequency interval, and the third frequency interval, respectively; the number of each frequency point is the quotient of the frequency value divided by the corresponding frequency interval.

[0051] S12. According to the numbering results and the numbering grouping rules, each frequency point in the ten-frequency segment point set, the one-hundred-frequency segment point set, and the one-thousand-frequency segment point set is grouped respectively to obtain a plurality of frequency band subgroups corresponding to each segment point set.

[0052] S13, superimposing the disturbance frequencies of all frequency points in each frequency band subgroup in turn and inputting them into the target system at the same time, calculating the voltage disturbance component and the current disturbance component after fast Fourier transformation in the target system according to the frequency band interval and numbering result corresponding to each frequency band subgroup, and selecting the impedance amplitude and phase.

[0053] In view of the impedance characteristics of the system, in the low frequency band (within the ten-frequency band), the disturbance has a more obvious impact on the small signal dynamic response of the system, and a slight change in the disturbance frequency will also lead to differences in the impedance characteristics; in the high frequency band (within the thousand-frequency band), the disturbance has less obvious impact on the small signal dynamic response of the system, and a large change in the disturbance frequency is required to see the difference in impedance characteristics. If the frequency selection method takes a value every 1Hz, the frequency points are spaced the same, which leads to insufficient distribution of frequency points in the low frequency band, and the impedance characteristics of the low frequency band cannot be accurately reflected. In the high frequency band, the frequency points are too densely distributed, which will produce some redundant results and reduce the efficiency of impedance analysis. This equally spaced frequency selection method will result in different resolutions of impedance characteristic results in high and low frequency bands. In the low frequency band, the results of key frequency points may be missed, and in the high frequency band, it is easy to cause a waste of computing power, which is obviously not the optimal disturbance frequency selection method. Therefore, in the low frequency band (within the ten frequency band), by setting the first frequency interval to increase to the frequency point, the system impedance characteristics of the low frequency band can be more accurately reflected; in the high frequency band (thousand frequency band), by reducing the third frequency interval to the frequency point, the time consumption of impedance analysis is greatly reduced, and the efficiency of impedance analysis is improved.

[0054] Exemplarily, the first frequency interval, the second frequency interval, and the third frequency interval are all powers of ten.

[0055] Specifically, for the convenience of illustration, the first frequency interval is set to 0.1 Hz, the second frequency interval is set to 1 Hz, and the third frequency interval is set to 10 Hz.

[0056] The specific plan is as follows:

[0057] 1) 1~10Hz, the first frequency interval is 0.1Hz, that is, the frequency points are 1.0, 1.1, 1.2, ..., 9.9, 10Hz;

[0058] 2) 10~100 Hz, the second frequency interval is 1 Hz, that is, the frequency points of 10, 11, 12, ..., 99, 100 Hz are taken;

[0059] 3) 100~1000 Hz, the third frequency interval is 10 Hz, that is, the frequency points are 100, 110, 120, ..., 990, 1000 Hz.

[0060] In the low frequency band (1-10Hz), the frequency points are increased from the original 10 to 91 points, which can more accurately reflect the system impedance characteristics of the low frequency band; in the high frequency band (100-1000Hz), the frequency points are reduced from the original 901 to 91 points, which greatly reduces the time consumption of impedance analysis and improves the efficiency of impedance analysis. The overall disturbance frequency points are reduced from the original 1000 to 271, and the efficiency is more than 3 times higher than the existing method. At the same time, the resolution of the impedance analysis results in the low and high frequency bands is taken into account, making the results more accurate.

[0061] After selecting the disturbance frequency points, group them.

[0062] Exemplarily, according to the numbering result and the numbering grouping rule, each frequency point in the ten-frequency segment point set, the one hundred-frequency segment point set, and the one thousand-frequency segment point set are grouped respectively to obtain multiple frequency band subgroups corresponding to each segment point set, specifically including:

[0063] In each segment point set, frequency points with prime numbers are selected to be divided into prime subgroups;

[0064] From the remaining frequency points of the segment point set, select the frequency points numbered multiples of 7 and group them into one group;

[0065] From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 5 and group them into one group;

[0066] From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 3 and group them into one group;

[0067] From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 2 and group them into one group.

[0068] This patent proposes a grouping scheme:

[0069] 1) Divide the 271 frequency points into three frequency bands. The first frequency band is 1-9.9 Hz, with a total of 90 points; the second frequency band is 10-99 Hz, with a total of 90 points; the third frequency band is 100-1000 Hz, with a total of 91 points.

[0070] 2) Number the points of each frequency band separately:

[0071] Number = disturbance frequency / frequency interval;

[0072] In this way, each frequency band is numbered 10, 11, 12, ..., 99, and the third frequency band will have an additional number 100.

[0073] 3) Frequencies in each band are grouped as follows:

[0074] Group 1: The frequencies that are prime numbers are grouped together, namely 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, and 97, for a total of 21 frequency points.

[0075] Group 2: The frequency points that are multiples of 7 are grouped together, namely 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, and 98, for a total of 13 frequency points.

[0076] Group 3: In addition to the numbers in group 2, the numbers that are multiples of 5 are grouped together, namely 10, 15, 20, 25, 30, 40, 45, 50, 55, 60, 65, 75, 80, 85, 90, 95, for a total of 16 frequency points (the third frequency band has one more number 100, for a total of 17 frequency points).

[0077] Group 4: Except for the numbers in group 2 and group 3, the numbers that are multiples of 3 are grouped together, namely 12, 18, 24, 27, 33, 36, 39, 48, 51, 54, 57, 66, 69, 72, 78, 81, 87, 93, 96, and 99, for a total of 20 frequency points.

[0078] Group 5: Except for the numbers in groups 2, 3 and 4, the numbers that are multiples of 2 are grouped together, namely 16, 22, 26, 32, 34, 38, 44, 46, 52, 58, 62, 64, 68, 74, 76, 82, 86, 88, 92, 94, for a total of 20 frequency points.

[0079] The advantage of this grouping is that 90 or 91 frequency points are divided into 5 groups more evenly, and the disturbance frequency in each group is a multiple of a certain number, which makes it easy to select a better frequency base value to meet the condition of "the disturbance frequency is a multiple of the frequency base value".

[0080] 4) Each group will use a different frequency base value for fast Fourier transform.

[0081] The frequency base value of group 1 = 1*frequency interval of the frequency band;

[0082] The frequency base value of group 2 = 7*frequency interval of the frequency band;

[0083] The frequency base value of group 3 = 5*frequency interval of the frequency band;

[0084] The frequency base value of group 4 = 3*frequency interval of the frequency band;

[0085] The frequency base value of group 5 = 2*frequency interval of the frequency band;

[0086] By setting the base frequency value in this way, the impedance analysis results will be better than the results when all disturbance frequencies are set at 1 Hz as the base frequency value.

[0087] Exemplarily, the step of calculating the voltage disturbance component and the current disturbance component after fast Fourier transformation in the target system and selecting the impedance amplitude and phase according to the frequency band interval and numbering result corresponding to each frequency band subgroup specifically includes:

[0088] The frequency base value is set according to the frequency band interval and numbering result corresponding to each frequency band subgroup; the frequency base value is a multiple of the corresponding frequency band interval;

[0089] According to the frequency base value, performing a fast Fourier transform on the voltage disturbance component and the current disturbance component in the target system;

[0090] According to the voltage disturbance component and the current disturbance component after the fast Fourier transformation, the impedance amplitude and phase of the target system under the influence of each frequency point are calculated.

[0091] After selecting the disturbance frequency points and grouping the frequency points, parallel frequency domain impedance analysis is started. The disturbances of all frequency points in the same group in a frequency band are superimposed and injected into the grid-connected port of the new energy power generation system at the same time. The three frequency bands are injected 15 times in total. Then, the voltage disturbance component and current disturbance component results after fast Fourier transformation are calculated based on the frequency base value of each group in each frequency band. Finally, the impedance amplitude and phase at the selected frequency point are calculated based on the voltage disturbance component and the current disturbance component.

[0092] Exemplarily, frequency points greater than 1000 Hz are selected from the disturbance frequency set to establish an additional segmentation point set;

[0093] According to the third frequency interval, numbering each frequency point in the additional segmentation point set;

[0094] The numbered additional segmentation point set is used as a frequency band subgroup corresponding to the thousand-frequency segmentation point set.

[0095] According to the impedance evaluation technical specifications of the energy industry standard, the disturbance frequency range should meet 2.5Hz ~ 1000Hz. If the disturbance frequency range changes, refer to the above numbering method, for frequencies above 1000Hz, they can also be grouped and calculated together in the third frequency band.

[0096] Compared with the prior art, the embodiment of the present invention provides a disturbance frequency grouping parallel impedance analysis method and device, which can more accurately reflect the system impedance characteristics of the low frequency band (within the ten frequency band) by setting the first frequency interval to increase to the frequency point; in the high frequency band (thousand frequency band), by reducing the third frequency interval to the frequency point, the time consumption of impedance analysis is greatly reduced, and the efficiency of impedance analysis is improved. And according to the numbering results, the frequency points concentrated in the segmentation points corresponding to the three segments of the ten frequency band, the hundred frequency band, and the thousand frequency band are grouped to obtain a plurality of frequency band sub-groups with a relatively even number of frequency points, and the disturbance frequency in each group is a multiple of a certain fixed value (the first frequency interval or the second frequency interval or the third frequency interval), which is convenient for selecting a better frequency base value for Fourier transform. In summary, the embodiment of the present invention takes into account the resolution of the impedance analysis results of the low frequency band and the high frequency band at the same time, making the results more accurate.

[0097] An embodiment of the present application provides a disturbance frequency grouping parallel impedance analysis device, including: a frequency selection module, a numbering module, a grouping module and an analysis module.

[0098] The frequency selection module is used to select frequency points from the disturbance frequency set according to the first frequency interval, the second frequency interval, and the third frequency interval in the ten-frequency band, the hundred-frequency band, and the thousand-frequency band, respectively, to establish a ten-frequency segment point set, a hundred-frequency segment point set, and a thousand-frequency segment point set in sequence; the ten-frequency band refers to 0Hz to 10Hz, the hundred-frequency band refers to 10Hz to 100Hz, and the thousand-frequency band refers to 100Hz to 1000Hz.

[0099] A numbering module is used to number each frequency point in the ten-frequency segment point set, the hundred-frequency segment point set, and the thousand-frequency segment point set according to the first frequency interval, the second frequency interval, and the third frequency interval, respectively; the number of each frequency point is the quotient of the frequency value divided by the corresponding frequency interval.

[0100] The grouping module is used to group each frequency point in the ten-frequency segment point set, the one-hundred-frequency segment point set, and the one-thousand-frequency segment point set according to the numbering results and the numbering grouping rules, so as to obtain multiple frequency band sub-groups corresponding to each segment point set.

[0101] The analysis module is used to sequentially superimpose the disturbance frequencies of all frequency points in each frequency band subgroup and input them into the target system at the same time, calculate the voltage disturbance component and current disturbance component after fast Fourier transformation in the target system according to the frequency band interval and numbering result corresponding to each frequency band subgroup, and select the impedance amplitude and phase.

[0102] Exemplarily, the grouping module is specifically used for:

[0103] In each segment point set, frequency points with prime numbers are selected to be divided into prime subgroups;

[0104] From the remaining frequency points of the segment point set, select the frequency points numbered multiples of 7 and group them into one group;

[0105] From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 5 and group them into one group;

[0106] From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 3 and group them into one group;

[0107] From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 2 and group them into one group.

[0108] Exemplarily, the step of calculating the voltage disturbance component and the current disturbance component after fast Fourier transformation in the target system and selecting the impedance amplitude and phase according to the frequency band interval and numbering result corresponding to each frequency band subgroup specifically includes:

[0109] The frequency base value is set according to the frequency band interval and numbering result corresponding to each frequency band subgroup; the frequency base value is a multiple of the corresponding frequency band interval;

[0110] According to the frequency base value, performing a fast Fourier transform on the voltage disturbance component and the current disturbance component in the target system;

[0111] According to the voltage disturbance component and the current disturbance component after the fast Fourier transformation, the impedance amplitude and phase of the target system under the influence of each frequency point are calculated.

[0112] Exemplarily, the first frequency interval, the second frequency interval, and the third frequency interval are all powers of ten.

[0113] Exemplarily, the frequency selection module is further used to: select frequency points greater than 1000 Hz from the disturbance frequency set to establish an additional segmentation point set;

[0114] The numbering module is further used to number each frequency point in the additional segmentation point set according to the third frequency interval;

[0115] The grouping module is further used to use the numbered additional segmentation point set as a frequency band sub-group corresponding to the thousand-frequency segmentation point set.

[0116] Compared with the prior art, an impedance analysis device with disturbance frequency grouping and parallel operation provided in an embodiment of the present invention can more accurately reflect the system impedance characteristics of the low frequency band by setting the first frequency interval to increase to the frequency point in the low frequency band (within the ten frequency band); and can greatly reduce the time consumption of impedance analysis and improve the efficiency of impedance analysis by reducing the third frequency interval to the frequency point in the high frequency band (thousand frequency band). In addition, the frequency points concentrated in the segmentation points corresponding to the three segments of the ten frequency band, the hundred frequency band, and the thousand frequency band are grouped to obtain a plurality of frequency band sub-groups with a relatively even number of frequency points. The disturbance frequencies in each group are multiples of a certain number (the first frequency interval or the second frequency interval or the third frequency interval), which facilitates the selection of a better frequency base value for Fourier transform. In summary, the embodiment of the present invention takes into account the resolution of the impedance analysis results of the low frequency band and the high frequency band at the same time, making the results more accurate.

[0117] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be described again here.

[0118] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A disturbance frequency grouping parallel impedance analysis method, characterized in that: include: Select frequency points from the disturbance frequency set in accordance with the first frequency interval, the second frequency interval and the third frequency interval in the ten-frequency band, the hundred-frequency band and the thousand-frequency band, respectively, and establish a ten-frequency segmentation point set, a hundred-frequency segmentation point set and a thousand-frequency segmentation point set in sequence; the ten-frequency band refers to 0 Hz to 10 Hz, the hundred-frequency band refers to 10 Hz to 100 Hz, and the thousand-frequency band refers to 100 Hz to 1000 Hz; wherein, in the ten-frequency band, the frequency points are increased by setting the first frequency interval; in the thousand-frequency band, the frequency points are reduced by the third frequency interval; Numbering each frequency point in the ten-frequency segment point set, the one-hundred-frequency segment point set, and the one-thousand-frequency segment point set according to the first frequency interval, the second frequency interval, and the third frequency interval, respectively; the number of each frequency point is the quotient of the frequency value divided by the corresponding frequency interval; According to the numbering results and the numbering grouping rules, each frequency point in the ten-frequency segment point set, the one-hundred-frequency segment point set, and the one-thousand-frequency segment point set is grouped respectively to obtain a plurality of frequency band subgroups corresponding to each segment point set; The disturbance frequencies of all frequency points in each frequency band subgroup are superimposed together in turn and input into the target system at the same time. According to the frequency band interval and numbering result corresponding to each frequency band subgroup, the voltage disturbance component and current disturbance component after fast Fourier transformation in the target system are calculated and the impedance amplitude and phase are obtained.

2. The impedance analysis method of disturbance frequency grouping in parallel as claimed in claim 1, characterized in that: The method of grouping each frequency point in the ten-frequency segment point set, the one hundred-frequency segment point set, and the one thousand-frequency segment point set according to the numbering result and the numbering grouping rule to obtain a plurality of frequency band subgroups corresponding to each segment point set specifically includes: In each segment point set, frequency points with prime numbers are selected to be divided into prime subgroups; From the remaining frequency points of the segment point set, select the frequency points numbered multiples of 7 and group them into one group; From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 5 and group them into one group; From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 3 and group them into one group; From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 2 and group them into one group.

3. The impedance analysis method of disturbance frequency grouping in parallel as claimed in claim 1, characterized in that: The step of calculating the voltage disturbance component and the current disturbance component after fast Fourier transformation in the target system and selecting the impedance amplitude and phase according to the frequency band interval and numbering result corresponding to each frequency band subgroup specifically includes: The frequency base value is set according to the frequency band interval and numbering result corresponding to each frequency band subgroup; the frequency base value is a multiple of the corresponding frequency band interval; According to the frequency base value, performing a fast Fourier transform on the voltage disturbance component and the current disturbance component in the target system; According to the voltage disturbance component and the current disturbance component after the fast Fourier transformation, the impedance amplitude and phase of the target system under the influence of each frequency point are calculated.

4. The impedance analysis method of disturbance frequency grouping in parallel as claimed in claim 1, characterized in that: The first frequency interval, the second frequency interval, and the third frequency interval are all powers of ten.

5. The impedance analysis method of disturbance frequency grouping in parallel as claimed in claim 1, characterized in that: Also includes: Select frequency points greater than 1000 Hz from the disturbance frequency set to establish an additional segmentation point set; According to the third frequency interval, numbering each frequency point in the additional segmentation point set; The numbered additional segmentation point set is used as a frequency band subgroup corresponding to the thousand-frequency segmentation point set.

6. An impedance analysis device with disturbance frequency grouping and parallel operation, characterized in that: include: A frequency selection module, for selecting frequency points from a disturbance frequency set in accordance with a first frequency interval, a second frequency interval, and a third frequency interval in a ten-frequency band, a hundred-frequency band, and a thousand-frequency band, respectively, to sequentially establish a ten-frequency segmentation point set, a hundred-frequency segmentation point set, and a thousand-frequency segmentation point set; the ten-frequency band refers to 0 Hz to 10 Hz, the hundred-frequency band refers to 10 Hz to 100 Hz, and the thousand-frequency band refers to 100 Hz to 1000 Hz; wherein, in the ten-frequency band, frequency points are increased by setting the first frequency interval; in the thousand-frequency band, frequency points are reduced by the third frequency interval; a numbering module, configured to number each frequency point in the ten-frequency segment point set, the hundred-frequency segment point set, and the thousand-frequency segment point set according to the first frequency interval, the second frequency interval, and the third frequency interval, respectively; the number of each frequency point is a quotient of a frequency value divided by a corresponding frequency interval; A grouping module, used for grouping each frequency point in the ten-frequency segment point set, the one-hundred-frequency segment point set, and the one-thousand-frequency segment point set according to the numbering result and the numbering grouping rule, to obtain a plurality of frequency band subgroups corresponding to each segment point set; The analysis module is used to sequentially superimpose the disturbance frequencies of all frequency points in each frequency band subgroup and simultaneously input them into the target system, and calculate the voltage disturbance component and current disturbance component after fast Fourier transformation in the target system according to the frequency band interval and numbering result corresponding to each frequency band subgroup, and obtain the impedance amplitude and phase.

7. The impedance analysis device with disturbance frequency grouping and parallel operation as claimed in claim 6, characterized in that: The grouping module is specifically used for: In each segment point set, frequency points with prime numbers are selected to be divided into prime subgroups; From the remaining frequency points of the segment point set, select the frequency points numbered multiples of 7 and group them into one group; From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 5 and group them into one group; From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 3 and group them into one group; From the remaining frequency points of the segment point set, select the frequency points whose numbers are multiples of 2 and group them into one group.

8. The impedance analysis device with disturbance frequency grouping and parallel operation as claimed in claim 6, characterized in that: The step of calculating the voltage disturbance component and the current disturbance component after fast Fourier transformation in the target system and selecting the impedance amplitude and phase according to the frequency band interval and numbering result corresponding to each frequency band subgroup specifically includes: The frequency base value is set according to the frequency band interval and numbering result corresponding to each frequency band subgroup; the frequency base value is a multiple of the corresponding frequency band interval; According to the frequency base value, performing a fast Fourier transform on the voltage disturbance component and the current disturbance component in the target system; According to the voltage disturbance component and the current disturbance component after the fast Fourier transformation, the impedance amplitude and phase of the target system under the influence of each frequency point are calculated.

9. The impedance analysis device with disturbance frequency groups in parallel as claimed in claim 6, wherein the first frequency interval, the second frequency interval, and the third frequency interval are all powers of 10.

10. The impedance analysis device with disturbance frequency grouping and parallel operation as claimed in claim 6, characterized in that: The frequency selection module is further used to: select frequency points greater than 1000 Hz from the disturbance frequency set to establish an additional segmentation point set; The numbering module is further used to number each frequency point in the additional segmentation point set according to the third frequency interval; The grouping module is further used to use the numbered additional segmentation point set as a frequency band sub-group corresponding to the thousand-frequency segmentation point set.

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