New energy multi-station short-circuit ratio combined treatment method based on iterative calculation

Abstract

The invention belongs to the field of station short-circuit ratio treatment, and particularly relates to a new energy multi-station short-circuit ratio combined treatment method based on iterative calculation. According to the method, two different schemes are adopted to treat a plurality of abnormal new energy stations, firstly, iterative treatment is performed on the abnormal new energy stations, secondly, grouping treatment is performed on the new energy stations, and the larger value of the capacity increment of each abnormal new energy field treatment device in the two treatment methods is compared, so that the new energy stations can be treated. The value is used as the capacity increment of the treatment device for treating the corresponding abnormal new energy station; according to the method, mutual promotion of multiple stations is realized through combined treatment of the multiple stations, and the scale of required treatment measures is smaller than the sum of the scales of treatment measures required by independent treatment of the stations, so that the short-circuit ratio of combined treatment of the multiple stations has relatively high treatment efficiency; the problems that an existing new energy station independently governs the short-circuit ratio configuration device is too large in scale, low in governing efficiency and difficult to land are solved.

Description

Technical Field

[0001] This application belongs to the field of station short-circuit ratio management, and specifically relates to an iteratively calculated method for joint management of short-circuit ratios of multiple new energy stations. Background Art

[0002] As the proportion of new energy in the power system continues to increase and the forms of new energy access become diversified, new energy has been integrated into weak AC power grids in some areas. This phenomenon will lead to problems such as wide-band oscillations and overvoltage. The short-circuit ratio of multiple new energy stations is an important indicator for evaluating the relative strength of the power grid under the interaction of multiple new energy groups. It has become a governance tool for dealing with the problem of a high proportion of new energy access to weak power grids.

[0003] The short-circuit ratio of multiple new energy stations is related to the output of each station and the mutual impedance between stations. Governance of any station will affect the mutual impedance between the station and other stations. The short-circuit ratio management of existing new energy stations mostly adopts a separate management method. Corresponding devices are separately configured for new energy stations with abnormal short-circuit ratios. However, the scale of the devices configured in the separate management method is too large, the management efficiency is low, and the equipment is difficult to implement. Summary of the Invention

[0004] To address the issues of existing new energy stations' single short-circuit ratio control equipment being too large, inefficient, and difficult to implement, this paper provides an iteratively calculated method for joint short-circuit ratio control at multiple new energy stations. By allocating implementation plans for joint control measures at multiple stations, the efficiency of short-circuit ratio control at the stations is improved.

[0005] An iteratively calculated joint management method for short-circuit ratios of multiple renewable energy stations, including:

[0006] Step 1: Set a first threshold E, calculate the short-circuit ratio of each new energy station, and identify new energy stations with a short-circuit ratio less than the first threshold E as abnormal new energy stations. Set the number of abnormal new energy stations to N.

[0007] Step 2: Iterate the abnormal new energy station obtained in step 1 to manage iteratively: increase the same capacity of the abnormal new energy station management device in each iteration until the short-circuit ratio of all new energy stations is greater than the first threshold E, and record the increase in the management device capacity of the nth new energy station as the first increased capacity A n ;n∈[1,2,3,···,N];

[0008] Step 3: Group and manage the abnormal new energy stations obtained in step 1: Divide the abnormal new energy stations obtained in step 1 into m groups according to the short-circuit ratio from small to large, and increase the same capacity of the management device of the abnormal new energy station in each group according to the group number from small to large so that the short-circuit ratio of the abnormal new energy station after the management device is increased by the same capacity reaches the level of the next group, until the short-circuit ratio of all new energy stations is greater than the first threshold E, and the increase in the capacity of the management device of the nth new energy station is recorded as the second increased capacity B n , m is an integer;

[0009] Step 4: Compare the first increase in capacity A n and the corresponding second increased capacity B n The size of A n and B n The maximum value is used as the nth abnormal new energy station joint governance short circuit ratio and the required governance device increases capacity D n .

[0010] The beneficial effects of the present invention are as follows: since the short-circuit ratio of multiple new energy stations is related to the output of each station and the mutual impedance between stations, the governance of any station will affect the mutual impedance with other stations, thereby having a governance and improvement effect on the short-circuit ratio of surrounding new energy stations; an iteratively calculated joint governance method for the short-circuit ratio of multiple new energy stations of the present application obtains the increase in the capacity of the governance device for governing each new energy station under two methods, respectively by iteratively governing the abnormal new energy stations and grouping the abnormal new energy stations, compares the obtained increase in the capacity of the governance device of all new energy stations, and takes the maximum value of the increase in the capacity of the governance device of the new energy station as the increase in the capacity of the governance device required for the joint governance of the short-circuit ratio of each abnormal new energy station; the method realizes mutual improvement of multiple stations through joint governance of multiple stations, and the scale of the required governance measures will be smaller than the sum of the scales of the governance measures required for the separate governance of each station, so the joint governance of the short-circuit ratio of multiple stations will have a higher governance efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a flow chart of a method for joint management of short-circuit ratios of multiple new energy stations using iterative calculations according to a specific embodiment of this application;

[0012] Figure 2 This is a flowchart of iterative management of abnormal new energy stations according to the specific implementation method of this application;

[0013] Figure 3 This is a flowchart for the group management of abnormal new energy stations according to the specific implementation method of this application. DETAILED DESCRIPTION

[0014] Specific implementation method 1: The following is combined with the attached embodiment of the present invention Figure 1 To the attached Figure 3 , illustrate this embodiment, and clearly and completely describe the technical solutions in the embodiments of the present invention:

[0015] An iteratively calculated joint management method for short-circuit ratios of multiple renewable energy stations, including:

[0016] Step 1: Set a first threshold E, calculate the short-circuit ratio of each new energy station, and identify new energy stations with a short-circuit ratio less than the first threshold E as abnormal new energy stations. Set the number of abnormal new energy stations to N.

[0017] Step 2: Iterate the abnormal new energy station obtained in step 1 to manage iteratively: increase the same capacity of the abnormal new energy station management device in each iteration until the short-circuit ratio of all new energy stations is greater than the first threshold E, and record the increase in the management device capacity of the nth new energy station as the first increased capacity A n ;n∈[1,2,3,···,N];

[0018] Step 3: Group and manage the abnormal new energy stations obtained in step 1: Divide the abnormal new energy stations obtained in step 1 into m groups according to the short-circuit ratio from small to large, and increase the same capacity of the management device of the abnormal new energy station in each group according to the group number from small to large so that the short-circuit ratio of the abnormal new energy station after the management device is increased by the same capacity reaches the level of the next group, until the short-circuit ratio of all new energy stations is greater than the first threshold E, and the increase in the capacity of the management device of the nth new energy station is recorded as the second increased capacity B n , m is an integer;

[0019] Step 4: Compare the first increase in capacity A n and the corresponding second increased capacity B n The size of A n and B n The maximum value is used as the nth abnormal new energy station joint governance short circuit ratio and the required governance device increases capacity D n .

[0020] Specifically, two different schemes are used to treat multiple abnormal new energy sites, and the larger value of the capacity increase of each abnormal new energy site treatment device in the two treatment methods is compared, and this value is used as the capacity increase of the treatment device of the corresponding abnormal new energy site;

[0021] First, the abnormal new energy stations are iteratively managed. In each round of iterative calculation, the management devices of each new energy station with a short-circuit ratio less than the first threshold E are uniformly increased by the same capacity until the short-circuit ratio of all new energy stations is greater than the first threshold E. The capacity increase A of the management device of each station is obtained. n; Secondly, the new energy stations are grouped and managed. The new energy stations with a short-circuit ratio less than the first threshold E are sorted from small to large according to the initial short-circuit ratio and divided into different groups (the group numbers are set from 1 to m, and the group with the lowest short-circuit ratio is the first group). First, the same capacity is uniformly increased for the management devices of the first group of new energy stations until the short-circuit ratio of the first group of new energy stations is increased to the level of the second group. Then, all new energy stations in the second group are uniformly managed until they reach the level of the third group. This is repeated until the short-circuit ratio of all new energy stations is greater than the first threshold E. The capacity increase B of the management device of each station is obtained. n ; Finally, compare A n and the corresponding B n The size of A n and B n The maximum value is used as the nth abnormal new energy station joint governance short circuit ratio and the required governance device increases capacity D n ;

[0022] The scale of the treatment equipment required by this method is smaller than the sum of the scales of the treatment equipment required for each new energy station to treat it separately. Therefore, the joint treatment of the short-circuit ratio by multiple stations will have a higher treatment efficiency, which promotes the improvement of the efficiency of the short-circuit ratio treatment of the stations.

[0023] Furthermore, the short-circuit ratio of the new energy station is calculated as follows:

[0024]

[0025] Among them, MRSCR i is the short-circuit ratio at the grid-connected busbar of the i-th new energy station; is the nominal voltage of the grid-connected busbar node of the i-th new energy station; is the grid-connected busbar node voltage of the i-th new energy station, is the short-circuit current of the i-th new energy station, is the short-circuit current of the j-th new energy station; is the equivalent mutual impedance between the i-th new energy station and the j-th new energy station, is the equivalent self-impedance of the i-th new energy station, j∈{1,2,3,···,N}.

[0026] Furthermore, the same capacity is added to the abnormal new energy station management device in each iteration until the short-circuit ratio of all new energy stations is greater than the first threshold E, and the capacity increase of the management device of the nth new energy station is recorded as A n , the methods include:

[0027] Step 21: Set the number of iterations to k, and let k = 1;

[0028] Step 22: Increase the capacity of the treatment devices of all abnormal new energy stations by ΔQ k, and calculate the increase in the capacity of the treatment device ΔQ k The short circuit ratio of each new energy station is MRSCR. n If the short-circuit ratio of the nth new energy station is less than the first threshold E, the nth new energy station is regarded as an abnormal new energy station; if the short-circuit ratio of the nth new energy station is greater than the first threshold E, the nth new energy station is regarded as a normal new energy station;

[0029] Step 23: Determine whether the number of abnormal new energy stations is 0. If so, go to step 24; if not, go to step 22;

[0030] Step 24: Record the increase in the capacity of the treatment device of the nth new energy station as the first increased capacity A n .

[0031] Specifically, if Figure 2 As shown, for all participating stations, the control devices (such as phase regulators) are uniformly increased in the same capacity and then the first round of calculations is carried out. If the short-circuit ratio of any station is greater than the first threshold E, it will not participate in the subsequent control. The remaining stations with a short-circuit ratio less than the first threshold E will all uniformly increase the capacity of the control devices and then carry out the second round of calculations. After the second round, the stations with a short-circuit ratio greater than the first threshold E will not participate in the subsequent increase in the capacity of the control devices. The stations with a short-circuit ratio less than the first threshold E will continue to uniformly increase the capacity of the control devices and carry out the next round of control, and so on, until the short-circuit ratios of all stations are greater than the first threshold E.

[0032] Furthermore, the abnormal new energy stations obtained in step 1 are divided into m groups according to the short-circuit ratio from small to large, and the same capacity is added to the treatment devices of the abnormal new energy stations in each group according to the group number from small to large so that the short-circuit ratio of the abnormal new energy stations after the treatment devices are increased by the same capacity reaches the level of the next group, until the short-circuit ratio of all new energy stations is greater than the first threshold E, and the increase in the capacity of the treatment device of the nth new energy station is recorded as the second increased capacity B n , the methods include:

[0033] Step 31: Set m-1 critical values, where the xth critical value C x Less than the x+1th critical value C x+1 , the m-1th critical value C m-1 Less than the first threshold E, x∈[1,2,3,···,m-2];

[0034] Step 32: When the nth new energy station short circuit ratio MRSCR n <C1, the nth new energy station is divided into the first group. When the nth new energy station short circuit ratio MRSCR n ∈[C x ,C x+1] then the i-th new energy station is divided into the x+1-th group. When the n-th new energy station short circuit ratio MRSCR n ∈[C m-1 ,E] then the nth new energy station is divided into the mth group;

[0035] Step 33: Set the governance group number to l, the governance times to z, let l = 1, z = 1, l∈[1,2,3,···,m], z is an integer;

[0036] Step 3 and 4: Increase the capacity of the treatment devices of all abnormal new energy stations in group l by ΔQ lz , calculate the capacity increase of the treatment device ΔQ lz Then the short circuit ratio of each new energy station in the lth group is regrouped; if the short circuit ratio of the nth new energy station MRSCR n <C1, the nth new energy station is divided into the first group. If the nth new energy station short circuit ratio MRSCR n ∈[C x ,C x+1 ] Then the nth new energy station is divided into the x+1th group. If the nth new energy station short circuit ratio MRSCR n ∈[C m-1 ,E] then the nth new energy station is divided into the mth group. When the nth new energy station short circuit ratio MRSCR n >E, the nth new energy station will be treated as a normal new energy station;

[0037] Step 35: Determine whether there are any abnormal new energy stations in group 1. If yes, go to step 36; if not, go to step 37.

[0038] Step 36: Set z = z + 1 and go to step 34;

[0039] Step 37: Determine whether l is equal to m. If not, set l = l + 1, z = 1, and go to step 34. If yes, record the increase in the capacity of the treatment device of the nth new energy station as the second capacity increase B. n .

[0040] Specifically, if Figure 3 As shown, the treatment is carried out in a way that the lower ones are matched first, the higher ones are matched later, and the qualified ones are caught up. First, the stations are divided into 1 to m groups according to the short-circuit ratio results from small to large. The group with the lowest short-circuit ratio, that is, the first group of new energy stations, is treated according to the iterative treatment method until the short-circuit ratio of the first group is improved to catch up with the short-circuit ratio level of the second group of stations; then all stations in the second group are iteratively treated to the level of the third group, and so on, until the short-circuit ratio of all stations is greater than the first threshold E.

[0041] Furthermore, the first critical value is greater than the minimum value of the short-circuit ratios of all abnormal new energy stations obtained in step one.

[0042] Furthermore, the treatment device is a distributed phase regulator, a stationary phase regulator or a networked device.

[0043] Specific embodiment 2: A computer-readable storage device, which stores a computer program. When the computer program is executed by a processor, it implements the steps of an iteratively calculated new energy multi-station short-circuit ratio joint management method as described in specific embodiment 1.

[0044] Specific embodiment three: An iteratively calculated new energy multi-station short-circuit ratio joint management device includes a storage device, a processor, and a computer program stored in the storage device and runnable on the processor. The processor executes the computer program to implement the steps of an iteratively calculated new energy multi-station short-circuit ratio joint management method as described in specific embodiment one.

[0045] Specific embodiment 4: A computer program product includes a computer program, which, when executed by a processor, implements the steps of an iteratively calculated new energy multi-station short-circuit ratio joint management method as described in specific embodiment 1.

[0046] Example: There are five abnormal new energy sites, namely wind farm 1, wind farm 2, wind farm 3, wind farm 4, and wind farm 5. Set a first threshold E = 2, and iteratively manage the five abnormal new energy sites, increasing the phase-shifting capacity by 10 Mvar each iteration.

[0047] The iterative governance plan for the five abnormal new energy stations is shown in the following table;

[0048]

[0049]

[0050] From the results in the table above, we can see that the five stations require a total of 500Mvar distributed phase regulators for individual governance, while the iterative governance solution only requires 230Mvar distributed phase regulators. In addition, the scale of governance measures for all stations is smaller than that for individual governance.

[0051] The grouping and management plan for the five abnormal new energy stations is shown in the following table;

[0052]

[0053]

[0054] The grouped control scheme requires a total distributed phase-shifting capacity of 210 Mvar, which is less than the individual control scheme and the first iterative control scheme. Since control of any station affects the mutual impedance with other stations, the short-circuit ratio of Wind Farms 3 and 4 still improves even without increasing their phase-shifting capacity in the table above.

[0055] According to the practical results, the short-circuit ratio of the stations that have completed the treatment first in the iterative treatment continues to increase gradually during the subsequent treatment of the remaining stations, and there is finally a certain short-circuit ratio margin. The stations that finally pass the treatment have just reached the qualified line, that is, the result of "easy to treat stations are treated more, and the pressure on difficult to treat stations is reduced" is obtained; in the group treatment, all stations try to reach the level of just passing as much as possible, and there is no problem of under-treatment after the station exits, and the total capacity of the treatment devices equipped at all stations is small, but there is a situation where the stations that are initially close to passing are driven to pass during the first group of stations' treatment and do not need to be treated, resulting in the treatment result of "easy to treat stations do not need to be treated, and difficult to treat stations are under great pressure".

[0056] Combining the two methods and in order to retain a certain governance margin, the larger value of the two results is taken as the final joint governance solution, that is: D n =max[A n ,B n ].

[0057] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It should be understood that many modifications may be made to the illustrative embodiments, and that other arrangements may be devised, without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in ways other than those described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be employed in conjunction with other described embodiments.

Claims

1. A joint management method for short-circuit ratio of multiple stations of new energy by iterative calculation, characterized in that: include: Step 1: Set a first threshold E, calculate the short-circuit ratio of each new energy station, and identify new energy stations with a short-circuit ratio less than the first threshold E as abnormal new energy stations. The number of abnormal new energy stations is N. Step 2: Calculate the first treatment device capacity A required for each new energy station after iterative treatment of the abnormal new energy station obtained in step 1 n : Each iteration increases the same capacity of the abnormal new energy station management device until the short-circuit ratio of all new energy stations is greater than the first threshold E; n∈[1,2,3,···,N]; Step 3: Calculate the second treatment device capacity B required for each new energy station after grouping treatment of the abnormal new energy stations obtained in step 1 n : The abnormal new energy stations obtained in step 1 are divided into m groups according to their short-circuit ratios from small to large. The abatement devices of the abnormal new energy stations in each group are sequentially increased in the same capacity according to the group numbers from small to large so that the short-circuit ratio of the abnormal new energy stations after the abatement devices are increased by the same capacity reaches the level of the next group, until the short-circuit ratio of all new energy stations is greater than a first threshold E, where m is an integer; Step 4: Compare the capacity A of the first treatment device n and the corresponding second treatment device capacity B n The size of A n and B n The maximum value is taken as the capacity D of the control device required for the nth abnormal new energy station joint control short-circuit ratio n .

2. The iteratively estimated new energy multi-station short-circuit ratio joint management method according to claim 1 is characterized by: The calculation method of the short-circuit ratio of new energy stations is: Among them, MRSCR i is the short-circuit ratio at the grid-connected busbar of the i-th new energy station; is the nominal voltage of the grid-connected busbar node of the i-th new energy station; is the grid-connected busbar node voltage of the i-th new energy station, is the short-circuit current of the i-th new energy station, is the short-circuit current of the j-th new energy station; is the equivalent mutual impedance between the i-th new energy station and the j-th new energy station, is the equivalent self-impedance of the i-th new energy station, j∈{1,2,3,···,N}.

3. The iteratively estimated new energy multi-station short-circuit ratio joint management method according to claim 1 is characterized by: The method of increasing the capacity of the abnormal new energy station management device by the same amount in each iteration until the short-circuit ratio of all new energy stations is greater than the first threshold E includes: Step 21: Set the number of iterations to k, and let k = 1; Step 22: Increase the capacity of the treatment devices of all abnormal new energy stations by ΔQ k , and calculate the increase in the capacity of the treatment device ΔQ k The short-circuit ratio of each new energy station is then calculated. If the short-circuit ratio of the n-th new energy station is less than the first threshold E, the n-th new energy station is considered an abnormal new energy station. If the short-circuit ratio of the n-th new energy station is greater than the first threshold E, the n-th new energy station is considered a normal new energy station. Step 23: Determine whether the number of abnormal new energy stations is 0. If so, go to step 24; if not, go to step 22; Step 24: Record the capacity of the treatment device of the nth new energy station as the first treatment device capacity A n .

4. The iteratively estimated new energy multi-station short-circuit ratio joint management method according to claim 1 is characterized by: The abnormal new energy stations obtained in step 1 are divided into m groups according to their short-circuit ratios from small to large, and the abnormal new energy station treatment devices in each group are sequentially increased in the same capacity according to the group numbers from small to large so that the short-circuit ratio of the abnormal new energy station after the treatment devices are increased by the same capacity reaches the level of the next group, until the short-circuit ratio of all new energy stations is greater than a first threshold E, the method comprising: Step 31: Set m-1 critical values, where the xth critical value C x Less than the x+1th critical value C x+1 , the m-1th critical value C m-1 Less than the first threshold E, x∈[1,2,3,···,m-2]; Step 32: When the nth new energy station short circuit ratio MRSCR n <C1, the nth new energy station is divided into the first group. When the nth new energy station short circuit ratio MRSCR n ∈[C x ,C x+1 ] then the i-th new energy station is divided into the x+1-th group. When the n-th new energy station short circuit ratio MRSCR n ∈[C m-1 ,E] then the nth new energy station is divided into the mth group; Step 33: Set the governance group number to l, the governance times to z, let l = 1, z = 1, l∈[1,2,3,···,m], z is an integer; Step 3 and 4: Increase the capacity of the treatment devices of all abnormal new energy stations in group l by ΔQ lz , calculate the capacity increase of the treatment device ΔQ lz Then the short circuit ratio of each new energy station in the lth group is regrouped; if the short circuit ratio of the nth new energy station MRSCR n <C1, the nth new energy station is divided into the first group. If the nth new energy station short circuit ratio MRSCR n ∈[C x ,C x+1 ] Then the nth new energy station is divided into the x+1th group. If the nth new energy station short circuit ratio MRSCR n ∈[C m-1 ,E] then the nth new energy station is divided into the mth group. When the nth new energy station short circuit ratio MRSCR n >E, the nth new energy station will be treated as a normal new energy station; Step 35: Determine whether there are any abnormal new energy stations in group 1. If yes, go to step 36; if not, go to step 37. Step 36: Set z = z + 1 and go to step 34; Step 37: Determine whether l is equal to m. If not, set l = l + 1, z = 1, and go to step 34. If yes, record the capacity of the treatment device of the nth new energy station as the second treatment device capacity B. n .

5. The iteratively estimated new energy multi-station short-circuit ratio joint management method according to claim 4 is characterized by: The first critical value is greater than the minimum value of the short-circuit ratios of all abnormal new energy stations obtained in step one.

6. The iteratively estimated new energy multi-station short-circuit ratio joint management method according to claim 1 is characterized by: The first threshold value E=2.

7. The iteratively estimated method for joint management of short-circuit ratios of multiple new energy stations according to claim 1 is characterized by: The treatment device is a distributed phase regulator, a static phase regulator or a network type device.

8. A computer-readable storage device storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the iteratively calculated new energy multi-station short-circuit ratio joint management method as described in any one of claims 1 to 4 are implemented.

9. An iteratively calculated new energy multi-station short-circuit ratio joint management device, comprising a storage device, a processor, and a computer program stored in the storage device and executable on the processor, characterized in that: The processor executes the computer program to implement the steps of the iteratively calculated new energy multi-station short-circuit ratio joint management method as described in any one of claims 1 to 4.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the iteratively calculated new energy multi-station short-circuit ratio joint management method as described in any one of claims 1 to 4 are implemented.

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