Distributed synchronous condenser configuration method and device based on voltage stiffness index

Abstract

The present invention relates to the field of power supply technology, and discloses a distributed synchronous condenser configuration method and device based on a voltage stiffness index, which are applied to a new energy power station including multiple input branches, and include: confirming the target voltage stiffness of each input branch, where the voltage stiffness is used to represent the voltage support degree; confirming the target capacity and target number of the distributed synchronous condensers arranged in each input branch according to the target voltage stiffness, and obtaining the station capacity and station number according to the sum of the target capacities and target numbers of each input branch; configuring the distributed synchronous condensers of the new energy power station based on the station capacity and station number, so as to configure the distributed synchronous condensers according to the target voltage support degree. The present invention solves the problems that in the existing distributed synchronous condenser configuration technology and index, due to the lack of phase angle information, the actual support effect of the distributed synchronous condenser cannot be accurately evaluated, and the configuration quantity and capacity of the distributed synchronous condenser that are more matched with the actual demand cannot be obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of power supplies, and particularly to a method and device for configuring a distributed synchronous condenser based on a voltage stiffness index. Background Art

[0002] To improve the voltage support capacity of the sending-end DC converter station and suppress the transient overvoltage of the sending-end DC system under transient fault conditions, the measures usually taken at present are to configure large-capacity centralized synchronous condensers at the AC busbars in the vicinity of the 500 kV or 750 kV DC converter stations feeding the sending end.

[0003] However, although the centralized synchronous condenser can effectively suppress the overvoltage of the connected substation or converter station, it is difficult to have an obvious effect on suppressing the overvoltage of medium-voltage or low-voltage new energy substations with a longer electrical distance. The distributed synchronous condenser can be an effective technology for suppressing the overvoltage problem of medium-voltage or low-voltage new energy substations. However, the current technologies and indicators for evaluating the voltage support effect of distributed synchronous condensers lack the phase angle information of relevant equipment, resulting in a certain deviation between the evaluation result and the actual effect, and thus it is difficult to obtain the configuration quantity and capacity of distributed synchronous condensers that are more matched to the actual requirements. Summary of the Invention

[0004] In view of this, the present invention provides a method and device for configuring a distributed synchronous condenser based on a voltage stiffness index to solve the problem that the existing distributed synchronous condenser configuration technologies and indicators lack the phase angle information of relevant equipment, resulting in the inability to accurately evaluate the actual support effect of the synchronous condenser and the inability to obtain the configuration quantity and capacity of distributed synchronous condensers that are more matched to the actual requirements.

[0005] In a first aspect, the present invention provides a method for configuring a distributed synchronous condenser based on a voltage stiffness index. The method for configuring a distributed synchronous condenser based on a voltage stiffness index is applied to a new energy substation including multiple input branches. The method includes:

[0006] Confirm the target voltage stiffness of each input branch, where the voltage stiffness is used to represent the voltage support degree;

[0007] Confirm the target capacity and target quantity of the distributed synchronous condensers arranged in each input branch according to the target voltage stiffness, and obtain the substation capacity and substation quantity according to the sum of the target capacities and target quantities of each input branch;

[0008] Configure the distributed synchronous condensers of the new energy substation based on the substation capacity and substation quantity to configure the distributed synchronous condensers according to the target voltage support degree.

[0009] The distributed synchronous condenser configuration method based on the voltage stiffness index provided by this embodiment uses the target voltage stiffness of each input branch in the new energy power station as an index to obtain the target capacity and target number of the distributed synchronous condensers to be set in each input branch. The station capacity and station number are obtained according to the sum of the target capacities and target numbers of each input branch, and the distributed synchronous condensers are configured according to the station capacity and station number, so that the voltage supported by the new energy power station can meet the overvoltage situation. Thus, a significant overvoltage suppression effect can be achieved.

[0010] In an alternative embodiment, the steps of determining the target capacity and target number of the distributed synchronous condensers set in each input branch according to the target voltage stiffness include:

[0011] Determine the initial capacity and initial number of the distributed synchronous condensers set in each input branch;

[0012] Take the initial capacity and initial number as the current capacity and current number, calculate the current voltage stiffness of the current capacity and current number, and perform iterative updates on the current capacity and current number according to the current voltage stiffness and the target voltage stiffness until the current voltage stiffness of each input branch meets its respective target voltage stiffness, and obtain the target capacity and target number of each input branch, where the difference between the updated voltage stiffness corresponding to the target capacity and target number and the target voltage stiffness is less than the preset difference threshold.

[0013] In an alternative embodiment, the steps of performing iterative updates on the current capacity and current number according to the current voltage stiffness and the target voltage stiffness include:

[0014] Calculate the total capacity of all input branches in the new energy power station, and calculate the current voltage stiffness under the current capacity and current number;

[0015] Obtain the capacity adjustment value according to the target voltage stiffness, total capacity, current capacity, current number, and current voltage stiffness;

[0016] Update and adjust the current capacity and current number according to the capacity adjustment value.

[0017] In an alternative embodiment, the input branch includes: a to-be-measured input branch and the remaining input branches. The steps of calculating the current voltage stiffness under the current capacity and current number include:

[0018] Under the current capacity and current number, respectively calculate the self-impedance vector of the remaining input branches, the grid-connected equipment impedance vector of the to-be-measured input branch, the grid-connected equipment impedance vector of the remaining input branches, and the grid impedance vector through the Thevenin equivalent circuit conversion formula;

[0019] Calculate the current voltage stiffness based on the self-impedance vectors of the remaining input branches, the impedance vectors of the grid-connected devices of the input branch to be measured, the impedance vectors of the grid-connected devices of the remaining input branches, and the grid impedance vector.

[0020] In an alternative embodiment, the step of calculating the current voltage stiffness at the current capacity and the current quantity includes:

[0021] Based on the electromagnetic transient simulation model of the new energy power station, obtain the transient voltage of the AC bus with multiple DC feed-ins and the no-load voltage of the AC bus with multiple DC feed-ins at the current capacity and the current quantity;

[0022] Based on the ratio of the voltage of the AC bus with multiple DC feed-ins to the no-load voltage of the AC bus with multiple DC feed-ins, obtain the current voltage stiffness.

[0023] In an alternative embodiment, the method further includes:

[0024] If the current voltage stiffness is lower than the target voltage stiffness, increase the current capacity and / or the current quantity;

[0025] If the current voltage stiffness is higher than the target voltage stiffness, decrease the current capacity and / or the current quantity.

[0026] In an alternative embodiment, the step of confirming the target voltage stiffness of each input branch includes:

[0027] Confirm the target voltage stiffness according to the actual voltage support requirements of each input branch; and / or,

[0028] Confirm the target voltage stiffness according to the voltage tolerance of each input branch.

[0029] In a second aspect, the present invention provides a distributed synchronous condenser configuration device based on a voltage stiffness index, and the device includes:

[0030] A first confirmation module, configured to confirm the target voltage stiffness of each input branch, where the voltage stiffness is used to represent the voltage support degree;

[0031] A second confirmation module, configured to confirm the target capacity and the target quantity of the distributed synchronous condensers set in each input branch according to the target voltage stiffness, and obtain the station capacity and the station quantity according to the sum of the target capacities and the target quantities of each input branch;

[0032] A configuration module, configured to configure the distributed synchronous condensers of the new energy power station based on the station capacity and the station quantity, so as to configure the distributed synchronous condensers according to the target voltage support degree.

[0033] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to perform the distributed synchronous condenser configuration method based on the voltage stiffness index according to the first aspect or any corresponding embodiment thereof as described above.

[0034] In a fourth aspect, the present invention provides a computer-readable storage medium, on which computer instructions are stored. The computer instructions are used to cause a computer to perform the distributed synchronous condenser configuration method based on the voltage stiffness index according to the first aspect or any corresponding embodiment thereof as described above.

[0035] In a fifth aspect, the present invention provides a computer program product, comprising computer instructions, which are used to cause a computer to perform the distributed synchronous condenser configuration method based on the voltage stiffness index according to the first aspect or any corresponding embodiment thereof as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1 is a schematic structural diagram of a centralized synchronous condenser;

[0038] Figure 2 is a flowchart of the distributed synchronous condenser configuration method based on the voltage stiffness index according to an embodiment of the present invention;

[0039] Figure 3 is an application schematic diagram of the distributed synchronous condenser configuration method based on the voltage stiffness index according to an embodiment of the present invention;

[0040] Figure 4 is another application schematic diagram of the distributed synchronous condenser configuration method based on the voltage stiffness index according to an embodiment of the present invention;

[0041] Figure 5 is another flowchart of the distributed synchronous condenser configuration method based on the voltage stiffness index according to an embodiment of the present invention;

[0042] Figure 6 is a structural block diagram of the distributed synchronous condenser configuration device based on the voltage stiffness index according to an embodiment of the present invention;

[0043] Figure 7It is a schematic diagram of the hardware structure of the computer device according to an embodiment of the present invention. Detailed implementation manners

[0044] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] In the related art, to improve the voltage support ability of the sending-end HVDC converter station and suppress the transient overvoltage of the sending-end DC system under transient fault conditions, the measures usually taken at present are to configure a large-capacity centralized synchronous condenser at the AC bus of the 500 kV or 750 kV high-voltage collection station feeding the sending-end HVDC converter station. Refer to Figure 1 , in the prior art, only one centralized synchronous condenser is provided at the collection station of all stations. However, although the centralized synchronous condenser can effectively suppress the overvoltage of the connected station or converter station, it is difficult to have an obvious effect on suppressing the overvoltage of medium-voltage or low-voltage new energy stations with a longer electrical distance. The distributed synchronous condenser can be an effective technology for suppressing the overvoltage problem of medium-voltage or low-voltage new energy stations. However, the current technologies and indicators for evaluating the voltage support effect of the distributed synchronous condenser lack the phase angle information of relevant equipment, resulting in a certain deviation between the evaluation result and the actual effect, and thus it is difficult to obtain the configuration quantity and capacity of the distributed synchronous condenser that better match the actual requirements.

[0046] According to an embodiment of the present invention, an embodiment of a method for configuring a distributed synchronous condenser based on a voltage stiffness index is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0047] In this embodiment, a method for configuring a distributed synchronous condenser based on a voltage stiffness index is provided, which can be used for the above-mentioned mobile terminals, such as mobile phones, tablet computers, etc. Figure 2 It is a flowchart of a method for configuring a distributed synchronous condenser based on a voltage stiffness index according to an embodiment of the present invention. As Figure 2 shown, the method for configuring a distributed synchronous condenser based on a voltage stiffness index is applied to a new energy station including multiple input branches, and this process includes the following steps:

[0048] Step S101, confirm the target voltage stiffness of each input branch, where the voltage stiffness is used to represent the voltage support degree.

[0049] Reference Figure 3 , the distributed synchronous condenser is a synchronous condenser with a certain capacity configured in medium-voltage or low-voltage new energy power stations in different regions, which realizes effective reactive power compensation and voltage support for the new energy power station. The new energy power station includes multiple input branches, and the input branches can be the power generation branches of a wind farm and / or the power generation branches of a photovoltaic power station. One or more distributed synchronous condensers can be set in each input branch. Of course, distributed synchronous condensers can also not be set. The grid-connected device is a grid-connected converter. Multiple input branches represent a multi-DC-fed new energy power station.

[0050] Specifically, the voltage stiffness is specifically expressed as the ratio of the AC bus voltage at the outlet of the new energy power station to the no-load voltage. The voltage parameters comprehensively include the amplitude and phase information of the equivalent impedance of the grid-connected device and the grid device, and more accurately characterize the overvoltage suppression and voltage support intensity effects under the condition of a multi-DC-fed new energy power station. The multiple input branches are the 1st input branch, the 2nd input branch... the i-th input branch respectively. Calculate the target voltage stiffness of each input branch in the new energy power station, which are the 1st target voltage stiffness, the 2nd target voltage stiffness... the i-th target voltage stiffness respectively. Optionally, the target voltage stiffness is specifically a value set by the user according to the actual situation.

[0051] Step S102, confirm the target capacity and target number of the distributed synchronous condensers set in each input branch according to the target voltage stiffness, and obtain the station capacity and station number according to the sum of the target capacities and target numbers of each input branch;

[0052] Specifically, calculate the target capacity and target number of the distributed synchronous condensers set in each input branch according to all the target voltage stiffness. The target capacity can be the unit capacity of a synchronous condenser. Therefore, the target number can vary according to the unit capacity of the distributed synchronous condenser. The product of the target capacity and the target number is the capacity to be configured for this input branch. Of course, the capacity of the distributed synchronous condensers set in each input branch can be confirmed only according to the target voltage stiffness, and the target capacity and target number can be set according to the capacity to be configured in each input branch. At this time, the distributed synchronous condensers of the new energy power station are the optimal configuration capacity.

[0053] Optionally, the target capacity and target number can be obtained according to a preset calculation model. The calculation model finds the target capacity and target number of each input branch whose actual voltage stiffness meets its respective target voltage stiffness threshold through calculation. The target voltage stiffness threshold can be a value within a preset range of the target voltage stiffness. Among them, the capacity and number of the distributed synchronous condensers are related to the actual voltage stiffness.

[0054] Step S103: Configure the distributed synchronous condensers for each input branch based on the substation capacity and the number of substations, so as to configure the distributed synchronous condensers according to the target voltage support level.

[0055] Specifically, one or more distributed synchronous condensers can be set in each input branch. Therefore, one or more distributed synchronous condensers can be set in the new energy substation. Different numbers and unit capacities of distributed synchronous condensers are set according to the different total capacities in the new energy substation.

[0056] Of course, the configuration method of the distributed synchronous condenser can also be applied to the centralized synchronous condenser in the collection station, and multiple input branches can be each new energy substation.

[0057] The configuration method of the distributed synchronous condenser based on the voltage stiffness index provided in this embodiment uses the target voltage stiffness of each input branch in the new energy substation as an index to obtain the target capacity and target number of the distributed synchronous condensers to be set in each input branch. The substation capacity and the number of substations are obtained according to the sum of the target capacities and target numbers of each input branch, and the distributed synchronous condensers are configured according to the substation capacity and the number of substations, so that the voltage supported by the new energy substation can meet the overvoltage condition. Thus, a significant overvoltage suppression effect can be achieved.

[0058] In some alternative embodiments, step S102 includes:

[0059] Step 1: Confirm the initial capacity and initial number of the distributed synchronous condensers set in each input branch;

[0060] Specifically, an initial capacity and an initial number are roughly set according to the actual situation in the new energy substation. Of course, each initial capacity and initial number can be set to a unified value.

[0061] Step 2: Take the initial capacity and initial number as the current capacity and current number, calculate the current voltage stiffness of the current capacity and current number, and perform iterative update on the current capacity and current number according to the current voltage stiffness and the target voltage stiffness until the current voltage stiffness of each input branch meets its respective target voltage stiffness, and obtain the target capacity and target number of each input branch, where the difference between the updated voltage stiffness corresponding to the target capacity and target number and the target voltage stiffness is less than the preset difference threshold.

[0062] Specifically, under the configuration of the initial capacity and the initial quantity of the distributed synchronous condensers, the voltage stiffness of each input branch is calculated, and the adjustment is made for each voltage stiffness according to a preset adjustment unit value. It should be noted that when adjusting the current capacity and the current quantity of one input branch, the current capacity and the current quantity of the remaining input branches may change accordingly. Therefore, in one round of iterative update, after adjusting the current capacity and the current quantity of each input branch respectively, the next round of iterative update is carried out. Finally, the target capacity and the target quantity are obtained in each input branch, where the difference between the updated voltage stiffness and the target voltage stiffness is less than the preset difference threshold. represents the voltage stiffness of the i-th input branch after the h-th round of update, represents the target voltage stiffness of the i-th input branch, and ε represents the set preset difference threshold. That is wherein, the difference between the updated voltage stiffness and the target voltage stiffness can take the absolute value, and m represents multiple input branches.

[0063] In some alternative embodiments, the step of "iteratively updating the current capacity and the current quantity according to the current voltage stiffness and the target voltage stiffness" in step two includes:

[0064] Step (1): Calculate the total capacity of all input branches in the new energy power station;

[0065] Specifically, Q Ci0 represents the initial capacity of a single distributed synchronous condenser of the i-th input branch, where i = 1, 2, 3,..., M, that is, the number of input branches of the new energy power station is M. N i0 represents the initial quantity, Q Ci0 N i0 represents the initial total capacity of the i-th input branch, Q CT represents the total capacity of the distributed synchronous condensers in the new energy power station, and h represents the h-th round of adjustment. That is

[0066] Step (2): Obtain the capacity adjustment value according to the target voltage stiffness, the total capacity, the current capacity, the current quantity, and the current voltage stiffness;

[0067] Specifically, ΔQ Ci，(h+1) represents the capacity adjustment value in the (h + 1)-th round, represents the target voltage stiffness of the i-th input branch, Q Ci，(h) represents the capacity of the distributed synchronous condenser of the i-th input branch after the h-th round of adjustment, that is, the current capacity, N Ci，(h) represents the quantity of the distributed synchronous condensers of the i-th input branch after the h-th round of adjustment, that is, the current quantity, Q CT,(h) represents the total quantity of the distributed synchronous condensers in the new energy power station after the h-th round of adjustment, Represents the voltage stiffness of the i-th branch after the h-th round of adjustment.

[0068]

[0069] Based on the total capacity of the distributed synchronous condensers in the new energy power station after the h-th round of adjustment, the capacity of the distributed synchronous condenser on the i-th input branch after the h-th round of adjustment, the voltage stiffness of the i-th branch after the h-th round of adjustment, the initial total capacity of the i-th input branch, and the target voltage stiffness of the i-th input branch, obtain the capacity adjustment value for the (h + 1)-th round.

[0070] That is to say, the capacity adjustment value for the (h + 1)-th round is proportional to the target difference ratio of the voltage stiffness and the ratio of the capacity of the distributed synchronous condenser on the i-th input branch after the h-th round of adjustment to the total capacity of the distributed synchronous condensers in the new energy power station after the h-th round of adjustment.

[0071] Step (3): Update and adjust the current capacity and current quantity according to the capacity adjustment value.

[0072] Specifically, after obtaining the capacity adjustment value for the (h + 1)-th round, adjust the total capacity of the h-th round to obtain the total capacity of the i-th input branch for the (h + 1)-th round.

[0073] Q Ci,(h+1) N i,(h+1) = Q Ci,h N i,h + ΔQ Ci,h+1

[0074] In some alternative embodiments, the input branch includes: the input branch to be measured and the remaining input branches. The step of "calculating the current voltage stiffness at the current capacity and current quantity" in step two includes:

[0075] Step (1): At the current capacity and current quantity, respectively calculate the self-impedance vector of the remaining input branches, the grid-connected equipment impedance vector of the input branch to be measured, the grid-connected equipment impedance vector of the remaining input branches, and the grid impedance vector through the Thevenin equivalent circuit conversion formula;

[0076] Step (2): Calculate the current voltage stiffness according to the self-impedance vector of the remaining input branches, the grid-connected equipment impedance vector of the input branch to be measured, the grid-connected equipment impedance vector of the remaining input branches, and the grid impedance vector.

[0077] Specifically, through the Thevenin equivalent circuit conversion formula, respectively deduce The Thevenin equivalent circuit conversion formula is not introduced in detail here. i represents the i-th input branch, and j represents the remaining input branches. That is, when j ≥ 2, j represents the cumulative value of multiple mutual impedances. Refer to Figure 4 , and equivalent (A) to (B). Represents the voltage stiffness of multiple input branches Represents the AC bus voltage of the i-th input branch, U i0 Represents the no-load voltage of the AC bus of the i-th input branch And Respectively represent the no-load voltage vector of the AC bus of the i-th input branch and the no-load voltage vector of the AC bus of j Represents the equivalent impedance vector of the power grid of multiple input branches Represents the mutual impedance vector between the i-th input branch and j Represents the self-impedance vector of j And Respectively represent the equivalent impedance vector of the grid-connected equipment of the i-th input branch and the equivalent impedance vector of the grid-connected equipment of j. According to relevant research and actual operation experience, generally

[0078]

[0079] In some alternative embodiments, the step of "calculating the current voltage stiffness at the current capacity and current quantity" in step a1 includes:

[0080] Step (3): Based on the electromagnetic transient simulation model of the new energy power station, obtain the transient voltage of the AC bus with multiple DC feed-ins and the no-load voltage of the AC bus with multiple DC feed-ins at the current capacity and current quantity;

[0081] Step (4): Based on the ratio of the AC bus voltage with multiple DC feed-ins to the no-load voltage of the AC bus with multiple DC feed-ins, obtain the current voltage stiffness.

[0082] Specifically, through the electromagnetic transient simulation model of the new energy power station, obtain And U i0 . That is, the transient voltage of the AC bus of the i-th input branch, U i0 Is the no-load voltage of the AC bus of the i-th input branch. Optionally, the simulation software can specifically be PSCAD (Power Systems Computer Aided Design, electromagnetic transient simulation) or Simulink (a visualization simulation tool), etc. Based on the structure of the new energy power station in the simulation software, build the corresponding electromagnetic transient simulation model, and simulate the no-load voltage values of the AC buses of each new energy power station and the overvoltage values under transient conditions through simulation, and calculate the voltage stiffness of the i-th through the formula of . That is

[0083] In some alternative embodiments, the configuration method of the distributed synchronous condenser further includes:

[0084] Step 1: If the current voltage stiffness is lower than the target voltage stiffness, increase the current capacity and / or the current quantity.

[0085] Step 2: If the current voltage stiffness is higher than the target voltage stiffness, decrease the current capacity and / or the current quantity.

[0086] Specifically, according to the obtained formula, it can be known that the main sensitivity parameters affecting the voltage stiffness of the input branch include parameters such as self-impedance, mutual impedance, equivalent impedance of equipment, and equivalent impedance of the power grid. The voltage stiffness of the input branch is inversely proportional to the equivalent impedance of the power grid and directly proportional to the equivalent impedance of the grid-connected equipment. In order to evaluate the relevant change trends of the voltage stiffness of multiple DC feed-ins with respect to the above self-impedance and mutual impedance, first, the partial derivatives of the voltage stiffness with respect to the two parameters are respectively derived.

[0087]

[0088] It can be seen that since the partial derivative of the voltage stiffness of the input branch with respect to the self-impedance is always less than zero, the voltage stiffness of the input branch and the self-impedance show a negatively correlated change trend.

[0089] According to the partial derivative of the voltage stiffness of the input branch with respect to the mutual impedance, it can be obtained that:

[0090]

[0091] Therefore, the voltage stiffness of the input branch and the mutual impedance show a negatively correlated change trend.

[0092] For the reactive power capacity Q absorbed by the AC collection bus of the new energy power station vi The derivatives with respect to the self-impedance and the mutual impedance respectively can be obtained as:

[0093]

[0094] It can be seen that the voltage stiffness is negatively correlated with both the self-impedance and the mutual impedance. Therefore, the voltage stiffness is positively correlated with the reactive power capacity generated or absorbed by the distributed synchronous condenser.

[0095] Therefore, if the current voltage stiffness is lower than the target voltage stiffness, increase the current capacity and / or the current quantity. If the current voltage stiffness is higher than the target voltage stiffness, decrease the current capacity and / or the current quantity.

[0096] In some alternative embodiments, the step of "confirming the target voltage stiffness of each input branch" in step S101 includes:

[0097] Step 1: Confirm the target voltage stiffness according to the actual voltage support requirements of each input branch; and / or,

[0098] Specifically, the optimal capacity of the distributed synchronous condenser is configured according to the voltage stiffness target values set for each input branch, and the maximum overvoltage level of the AC bus is usually taken as 1.3 p.u.

[0099] Step 2: Confirm the target voltage stiffness according to the voltage tolerance of each input branch.

[0100] Specifically, the target voltage stiffness can also be confirmed according to the actual voltage tolerance of each input branch.

[0101] Reference Figure 5 , according to the actual engineering plan, determine the number and capacity of the new energy converter grid-connected devices included in each medium-voltage or low-voltage (such as 110 kV, 220 kV or 330 kV) new energy power station. According to the basic criteria and experience of the reactive power compensation configuration of the new energy power station, configure the distributed synchronous condensers with the initial number and initial capacity at the AC buses of each DC feed-in. Respectively derive the equivalent impedance of each new energy grid-connected device and the equivalent electromotive force and equivalent impedance of the input branch through the Thevenin equivalent circuit transformation. Based on the obtained formulas, calculate the voltage stiffness of the AC buses of each DC feed-in in each new energy power station. Or, by simulating the no-load voltage values and overvoltage values under transient conditions of the AC buses of each new energy power station, calculate the voltage stiffness of the AC buses of each new energy power station based on the obtained formulas. If it is detected that the condition is met, determine that the distributed synchronous condenser configuration result at this time is the optimal configuration capacity of the distributed synchronous condensers in each new energy power station. If the condition is not met, calculate the capacity of the distributed synchronous condenser that needs to be increased or decreased for the i-th multi-DC feed-in AC bus during the (h + 1)-th round of adjustment, then calculate the capacity of the distributed synchronous condenser at the i-th multi-DC feed-in AC bus after the (h + 1)-th round of adjustment, and calculate the adjustment capacity of the distributed synchronous condensers at the multi-DC feed-in AC buses of all new energy power stations, and return to the step of calculating the voltage stiffness of the AC buses of each DC feed-in in each new energy power station based on the obtained formulas until the condition is met.

[0102] In this embodiment, a distributed synchronous condenser configuration device based on the voltage stiffness index is also provided. This device is used to implement the above-mentioned embodiments and preferred implementation manners, and those that have been described will not be repeated here. As used below, the term "module" can be a combination of software and / or hardware that can achieve a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0103] This embodiment provides a distributed synchronous condenser configuration device based on voltage stiffness index, as Figure 6 shown, including:

[0104] A first confirmation module 501, configured to confirm the target voltage stiffness of each input branch, where the voltage stiffness is used to represent the voltage support degree.

[0105] A second confirmation module 502, configured to confirm the target capacity and target number of the distributed synchronous condensers set in each input branch according to the target voltage stiffness, and obtain the substation capacity and substation number according to the sum of the target capacities and target numbers of each input branch.

[0106] A configuration module 503, configured to configure the distributed synchronous condensers of the new energy substation based on the substation capacity and substation number, so as to configure the distributed synchronous condensers according to the target voltage support degree.

[0107] In some optional implementation manners, the second confirmation module 502 includes:

[0108] A first confirmation unit, configured to confirm the initial capacity and initial number of the distributed synchronous condensers set in each input branch;

[0109] An update unit, taking the initial capacity and initial number as the current capacity and current number, calculating the current voltage stiffness of the current capacity and current number, and performing iterative update on the current capacity and current number according to the current voltage stiffness and the target voltage stiffness until the current voltage stiffness of each input branch meets its respective target voltage stiffness, and obtaining the target capacity and target number of each input branch, where the difference between the updated voltage stiffness corresponding to the target capacity and target number and the target voltage stiffness is less than a preset difference threshold.

[0110] In some optional implementation manners, the update unit includes:

[0111] A first calculation sub-unit, configured to calculate the total capacity of all input branches in the new energy substation, and calculate the current voltage stiffness under the current capacity and current number;

[0112] A second calculation sub-unit, configured to obtain a capacity adjustment value according to the target voltage stiffness, the total capacity, the current capacity, the current number, and the current voltage stiffness.

[0113] In some optional implementation manners, the input branch includes: a to-be-measured input branch and the remaining input branches, and the update unit further includes:

[0114] A third calculation subunit, configured to calculate, based on the current capacity and the current quantity, the self-impedance vector of the remaining input branches, the grid-connected device impedance vector of the input branch to be measured, the grid-connected device impedance vector of the remaining input branches, and the grid impedance vector respectively through the Thevenin equivalent circuit conversion formula;

[0115] A fourth calculation subunit, configured to calculate the current voltage stiffness according to the self-impedance vector of the remaining input branches, the grid-connected device impedance vector of the input branch to be measured, the grid-connected device impedance vector of the remaining input branches, and the grid impedance vector.

[0116] In some alternative embodiments, the update unit includes:

[0117] A simulation subunit, configured to obtain the transient voltage of the AC bus with multiple DC feed-ins and the no-load voltage of the AC bus with multiple DC feed-ins at the current capacity and the current quantity based on the electromagnetic transient simulation model of the new energy power station;

[0118] A fifth calculation subunit, configured to obtain the current voltage stiffness based on the ratio of the voltage of the AC bus with multiple DC feed-ins to the no-load voltage of the AC bus with multiple DC feed-ins.

[0119] In some alternative embodiments, the device is further configured to increase the current capacity and / or the current quantity if the current voltage stiffness is lower than the target voltage stiffness; and decrease the current capacity and / or the current quantity if the current voltage stiffness is higher than the target voltage stiffness.

[0120] In some alternative embodiments, the first confirmation module 501 includes:

[0121] A second confirmation unit, configured to confirm the target voltage stiffness according to the actual voltage support requirements of each input branch; and / or,

[0122] A third confirmation unit, configured to confirm the target voltage stiffness according to the voltage tolerance of each input branch.

[0123] The further function descriptions of the above-mentioned various modules and units are the same as those in the corresponding foregoing embodiments, and will not be elaborated herein.

[0124] The distributed synchronous condenser configuration device based on the voltage stiffness index in this embodiment is presented in the form of functional units. Here, the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and a memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0125] This embodiment of the present invention further provides a computer device having the above-mentioned Figure 6 distributed synchronous condenser configuration device based on the voltage stiffness index as shown.

[0126] See also Figure 7 , Figure 7 Schematic diagram of the hardware structure of the computer device according to the embodiment of the present invention. Figure 7 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 7 A processor 10 is taken as an example.

[0127] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0128] The memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiment.

[0129] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0130] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0131] The computer device further includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30, and the output device 40 may be connected through a bus or other means. For example, taking the connection through the bus as an example. Figure 7 For example, taking the connection through the bus as an example.

[0132] The input device 30 can receive input digital or character information, and generate key signal inputs related to the user settings and function controls of the computer device, such as a touch screen, a keypad, a mouse, a trackpad, a touchpad, a pointing stick, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (for example, an LED), and a haptic feedback device (for example, a vibration motor), etc. The above display device includes but is not limited to a liquid crystal display, a light emitting diode, a display, and a plasma display. In some alternative embodiments, the display device may be a touch screen.

[0133] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or be implemented as computer code that can be recorded on a storage medium, or be implemented as computer code that is originally stored in a remote storage medium or a non-transitory machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk, or a solid-state drive, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by the computer, the processor, or the hardware, the method shown in the above embodiment is implemented.

[0134] A part of the present invention can be applied as a computer program product, such as computer program instructions. When executed by a computer, through the operation of the computer, the methods and / or technical solutions according to the present invention can be called or provided. Those skilled in the art should be able to understand that the forms in which computer program instructions exist in a computer-readable medium include but are not limited to source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include but are not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible by the computer.

[0135] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A distributed synchronous condenser configuration method based on voltage stiffness index, characterized in that The distributed synchronous condenser configuration method based on the voltage stiffness index is applied to a new energy power station including multiple input branches, and the method includes: Confirm the target voltage stiffness of each input branch, where the voltage stiffness is used to represent the voltage support degree; Confirm the target capacity and target number of the distributed synchronous condensers set in each input branch according to the target voltage stiffness, and obtain the station capacity and station number according to the sum of the target capacities and target numbers of each input branch; Configure the distributed synchronous condensers of the new energy power station based on the station capacity and the station number, so as to configure the distributed synchronous condensers according to the target voltage support degree; Among them, the step of confirming the target capacity and target number of the distributed synchronous condensers set in each input branch according to the target voltage stiffness includes: Confirm the initial capacity and initial number of the distributed synchronous condensers set in each input branch; Take the initial capacity and initial number as the current capacity and current number, calculate the current voltage stiffness under the current capacity and current number, and perform iterative update on the current capacity and current number according to the current voltage stiffness and the target voltage stiffness until the current voltage stiffness of each input branch meets its respective target voltage stiffness, and obtain the target capacity and target number of each input branch, where the difference between the updated voltage stiffness corresponding to the target capacity and target number and the target voltage stiffness is less than a preset difference threshold.

2. The method according to claim 1, wherein The step of performing iterative update on the current capacity and current number according to the current voltage stiffness and the target voltage stiffness includes: Calculate the total capacity of all input branches in the new energy power station; Obtain a capacity adjustment value according to the target voltage stiffness, the total capacity, the current capacity, the current number, and the current voltage stiffness; Perform update adjustment on the current capacity and current number according to the capacity adjustment value.

3. The method according to claim 1, wherein The input branch includes: a to-be-measured input branch and the remaining input branches, and the step of calculating the current voltage stiffness under the current capacity and current number includes: Under the current capacity and current number, respectively calculate the self-impedance vector of the remaining input branches, the grid-connected device impedance vector of the to-be-measured input branch, the grid-connected device impedance vector of the remaining input branches, and the grid impedance vector through the Thevenin equivalent circuit conversion formula; Calculate the current voltage stiffness according to the self-impedance vector of the remaining input branches, the grid-connected device impedance vector of the to-be-measured input branch, the grid-connected device impedance vector of the remaining input branches, and the grid impedance vector.

4. The method according to claim 1, characterized in that The step of calculating the current voltage stiffness under the current capacity and current number includes: Based on the electromagnetic transient simulation model of the new energy power station, obtain the transient voltage of the AC bus with multiple DC feed-ins and the no-load voltage of the AC bus with multiple DC feed-ins under the current capacity and current number; Obtain the current voltage stiffness based on the ratio of the voltage of the AC bus with multiple DC feed-ins to the no-load voltage of the AC bus with multiple DC feed-ins.

5. The method according to claim 1, characterized in that, The method further includes: If the current voltage stiffness is lower than the target voltage stiffness, increase the current capacity and / or the current quantity; If the current voltage stiffness is higher than the target voltage stiffness, decrease the current capacity and / or the current quantity.

6. The method according to claim 1, wherein The step of confirming the target voltage stiffness of each input branch includes: Confirming the target voltage stiffness according to the actual voltage support requirement of each input branch; and / or, Confirming the target voltage stiffness according to the voltage tolerance of each input branch.

7. A distributed synchronous condenser configuration device based on a voltage stiffness index, characterized in that The distributed synchronous condenser configuration device based on the voltage stiffness index includes: A first confirmation module, configured to confirm the target voltage stiffness of each input branch, where the voltage stiffness is used to represent the voltage support degree; A second confirmation module, configured to confirm the target capacity and target quantity of the distributed synchronous condensers arranged in each input branch according to the target voltage stiffness, and obtain the substation capacity and substation quantity according to the sum of the target capacities and target quantities of each input branch; where, the step of confirming the target capacity and target quantity of the distributed synchronous condensers arranged in each input branch according to the target voltage stiffness includes: Confirming the initial capacity and initial quantity of the distributed synchronous condensers arranged in each input branch; Taking the initial capacity and initial quantity as the current capacity and current quantity, calculating the current voltage stiffness under the current capacity and current quantity, and performing iterative update on the current capacity and the current quantity according to the current voltage stiffness and the target voltage stiffness until the current voltage stiffness of each input branch meets its respective target voltage stiffness, and obtaining the target capacity and target quantity of each input branch, where the difference between the updated voltage stiffness corresponding to the target capacity and target quantity and the target voltage stiffness is less than a preset difference threshold; A configuration module, configured to configure the distributed synchronous condensers of the new energy substation based on the substation capacity and the substation quantity, so as to configure the distributed synchronous condensers according to the target voltage support degree.

8. A computer device, characterized in that, Including: A memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to execute the distributed synchronous condenser configuration method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, Computer instructions are stored on the computer-readable storage medium, and the computer instructions are used to cause a computer to execute the distributed synchronous condenser configuration method according to any one of claims 1 to 6.

10. A computer program product, characterized in that, Including computer instructions, the computer instructions are used to cause a computer to execute the distributed synchronous condenser configuration method according to any one of claims 1 to 6.

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