Method and device for selecting access node of phase modifier

Abstract

The invention discloses a method and device for selecting access nodes of a phase modifier, and belongs to the field of alternating current system control, and the method comprises the steps: determining target impedance data of a phase modifier site selection scheme; in combination with the target impedance data and the rated power of each converter bus, calculating a multi-infeed short-circuit ratio and a multi-infeed interaction factor of each converter bus; and when it is determined that the multi-infeed interaction factors between the converter buses are not greater than the impedance ratio between the converter buses and the phase modifier access nodes, according to the target impedance data, the weight parameters of the converter buses, the rated power, the multi-infeed short-circuit ratio and the multi-infeed interaction factors, calculating to obtain a total target function value of the phase modifier site selection scheme. And taking the node accessed by the phase modifier in the phase modifier site selection scheme with the highest total objective function value as the final access node of the phase modifier. By implementing the method and the device, the problems of overlong calculation period and high simulation cost caused by solving the phase modifier site selection by relying on electromagnetic transient simulation in the prior art can be solved.

Description

Technical Field

[0001] This invention relates to the field of AC system control, and more particularly to a method and apparatus for selecting a synchronous condenser access node. Background Technology

[0002] With the continuous expansion of long-distance, large-capacity DC transmission projects, complex multi-DC-feed receiving-end power grid structures have formed in load center areas. Introducing synchronous condensers is an important means to improve the voltage support capacity of the receiving-end AC system and reduce the risk of commutation failure. However, due to the high investment cost of synchronous condensers, they cannot be deployed on a large scale on every converter bus. Therefore, scientifically and rationally determining the synchronous condenser access nodes has become an important issue in power grid planning and operation.

[0003] Existing synchronous condenser location methods mostly rely on large-scale electromagnetic transient simulations, which apply fault disturbances to all nodes in the entire network one by one and analyze the response in order to obtain the sensitivity and importance indicators of each node. Such methods can be applied in small-scale systems with a limited number of nodes, but in multi-infeed DC receiving-end power grids with a large number of converter stations, complex AC grid structure, and dense coupling relationships, the computational scale grows exponentially, resulting in excessively long computation cycles and high simulation costs, making it difficult to meet the needs of engineering practice for rapid optimization and real-time decision-making. Summary of the Invention

[0004] This invention provides a method and apparatus for selecting a synchronous condenser access node. The method can solve the problems of excessively long calculation cycles and high simulation costs caused by the existing technology of relying on electromagnetic transient simulation to solve the location of synchronous condensers.

[0005] An embodiment of the present invention provides a method for selecting a camera access node, comprising: The initial impedance data of the target AC system, the rated power of each converter bus in the target AC system, and several synchronous condenser location schemes are obtained; wherein, each synchronous condenser location scheme includes weight parameters for each converter bus. For each synchronous condenser location scheme, the initial impedance data is adjusted according to the node impedance of the synchronous condenser access node in the current synchronous condenser location scheme to obtain the target impedance data; Based on the target impedance data and the rated power of each converter bus, the multi-infeed short-circuit ratio and multi-infeed interaction factor of each converter bus are calculated. Based on the target impedance data, the ratio of the impedance between each converter bus and the synchronous condenser access node is calculated. Determine whether the multi-infeed interaction factor between each converter bus is not greater than the ratio. If so, calculate the total objective function value of the current synchronous condenser location scheme based on the target impedance data, the weight parameters of each converter bus, the rated power, the multi-infeed short-circuit ratio, and the multi-infeed interaction factor. If not, discard the current synchronous condenser location scheme. The synchronous condenser location scheme with the highest overall objective function value is selected as the target synchronous condenser location scheme, and the node connected to the synchronous condenser in the target synchronous condenser location scheme is taken as the final access node of the synchronous condenser.

[0006] Furthermore, the node impedance of the synchronous condenser access node includes the self-impedance of the synchronous condenser access node and the mutual impedance between the synchronous condenser access node and the remaining nodes in the target AC system. The step of adjusting the initial impedance data according to the node impedance of the camera access node in the current camera location scheme to obtain the target impedance data includes: Based on the self-impedance of the synchronous condenser access node in the current synchronous condenser location scheme and the mutual impedance between the synchronous condenser access node and the remaining nodes in the target AC system, the initial impedance data is adjusted to obtain the target impedance data; wherein, the initial impedance between any two nodes in the initial impedance data is adjusted using the following formula: ; In the formula, Represents a node With nodes The initial impedance between; To adjust the camera access node Self-impedance; Indicates camera access node With nodes mutual impedance; Indicates camera access node With nodes The mutual impedance.

[0007] Furthermore, the calculation of the multi-infeed short-circuit ratio and multi-infeed interaction factor of each converter bus based on the target impedance data and the rated power of each converter bus includes: Based on the target impedance data, the multi-feed interaction factor between each converter bus in the target AC system is calculated. Based on the rated power of each converter bus and the target impedance data, the multi-feed short-circuit ratio of each converter bus in the target AC system is calculated.

[0008] Further, the step of calculating the multi-feed interaction factor between each converter bus in the target AC system based on the target impedance data includes: The multi-feedback interaction factor is calculated using the following formula: ; In the formula, Indicates converter bus With converter bus Multiple feed-in interaction factors between them; Indicates converter bus With converter bus mutual impedance; This represents the equivalent impedance of the branch where the camera module access node is located; Indicates converter bus Access node with condenser mutual impedance; Indicates converter bus Access node with condenser mutual impedance; Indicates converter bus Self-impedance.

[0009] Further, the step of calculating the multi-infeed short-circuit ratio of each converter bus in the target AC system based on the target impedance data includes: The multi-feed short-circuit ratio is calculated using the following formula: ; In the formula, Indicates the multi-feed short-circuit ratio; Indicates camera access node With converter bus mutual impedance; Indicates the total number of converter buses; Indicates camera access node With converter bus mutual impedance; Indicates converter bus Rated power; Indicates converter bus Rated power.

[0010] Furthermore, the total objective function value includes a first objective function value and a second objective function value; The overall objective function value of the current synchronous condenser location scheme is calculated based on the target impedance data, the weight parameters of each converter bus, the rated power, the multi-infeed short-circuit ratio, and the multi-infeed interaction factor, including: The first objective function value is calculated based on the target impedance data, the weight parameters of each converter bus, and the multi-feed interaction factor. The second objective function value is calculated based on the target impedance data, the weight parameters of each converter bus, the rated power, and the multi-infeed short-circuit ratio. The total objective function value of the current synchronous condenser location scheme is calculated based on the first objective function value and the second objective function value.

[0011] Further, the step of calculating the first objective function value based on the target impedance data, the weight parameters of each converter bus, and the multi-feed interaction factor includes: The value of the first objective function is calculated using the following formula: ; In the formula, This represents the value of the first objective function; Indicates converter bus The weight parameters.

[0012] Further, the calculation of the second objective function value based on the target impedance data, the weight parameters of each converter bus, the rated power, and the multi-infeed short-circuit ratio includes: The value of the second objective function is calculated using the following formula: ; In the formula, Indicates camera access node With converter bus The mutual impedance.

[0013] Furthermore, the weight parameters of each converter bus are determined in the following manner: Based on the node impedance of the three-phase symmetrical reactor access node in the target impedance data, the voltage coupling factor of each converter bus is calculated. The number of converter buses whose voltage coupling factor exceeds the corresponding critical voltage coupling factor is counted and used as the first number; The weight parameters of each converter bus are determined based on the total number of converter buses in the target AC system and the first quantity.

[0014] An embodiment of the present invention also provides a device for selecting a camera access node, comprising: The data acquisition module is used to acquire the initial impedance data of the target AC system, the rated power of each converter bus in the target AC system, and several synchronous condenser location schemes; wherein, each synchronous condenser location scheme includes the weight parameters of each converter bus. The data adjustment module is used to adjust the initial impedance data according to the node impedance of the synchronous condenser access node in the current synchronous condenser location scheme for each synchronous condenser location scheme, so as to obtain the target impedance data. The first calculation module is used to calculate the multi-infeed short-circuit ratio and multi-infeed interaction factor of each converter bus based on the target impedance data and the rated power of each converter bus. The second calculation module is used to calculate the ratio of the impedance between each converter bus and the synchronous condenser access node based on the target impedance data. The scheme selection module is used to determine whether the multi-infeed interaction factor between each converter bus is not greater than the ratio. If so, the total objective function value of the current synchronous condenser location scheme is calculated based on the target impedance data, the weight parameters of each converter bus, the rated power, the multi-infeed short-circuit ratio and the multi-infeed interaction factor. If not, the current synchronous condenser location scheme is discarded. The access node determination module is used to select the camera condenser location scheme with the highest total objective function value as the target camera condenser location scheme, and to select the node to which the camera condenser is connected in the target camera condenser location scheme as the final access node of the camera condenser.

[0015] The following benefits can be obtained by implementing the present invention: This invention provides a method and apparatus for selecting a synchronous condenser access node. For each synchronous condenser location scheme, the method adjusts the initial impedance data based on the node impedance of the synchronous condenser access node in the current scheme to obtain target impedance data. Then, based on the target impedance data and the rated power of each converter bus, the multi-infeed short-circuit ratio and multi-infeed interaction factor of each converter bus are calculated. Thus, the voltage support capability and commutation failure risk suppression effect of the converter bus under the current scheme are evaluated through the multi-infeed short-circuit ratio and multi-infeed interaction factor. Next, based on the target impedance data, the ratio of the impedance between each converter bus and the synchronous condenser access node is calculated, and it is determined whether the multi-infeed interaction factor between each converter bus is not greater than the ratio. If so, based on the target impedance data, the weight parameters of each converter bus, the rated power, and the multi-infeed short-circuit ratio... The overall objective function value of the current synchronous condenser location scheme is calculated by considering the multi-infeed interaction factor. If not, the current synchronous condenser location scheme is discarded. Therefore, by determining whether the multi-infeed interaction factors between each converter bus are all less than the stated ratio, schemes that meet the commutation failure risk constraint are selected. Finally, the synchronous condenser location scheme with the highest overall objective function value is selected as the target synchronous condenser location scheme, and the node where the synchronous condenser is connected in the target scheme is taken as the final connection node of the synchronous condenser. Thus, through rapid correction of the node impedance matrix and analytical calculation of key multi-infeed indicators, risk assessment and objective function solution for a single scheme can be quickly completed without building a complex electromagnetic transient simulation model, significantly reducing hardware resource consumption and manual modeling costs. This ensures the accuracy of the commutation failure risk suppression effect and achieves efficient and low-cost selection of synchronous condenser location schemes. Attached Figure Description

[0016] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating a method for selecting a synchronous condenser access node according to a certain embodiment of this application; Figure 2 This is a schematic diagram of an equivalent target communication system provided in a certain embodiment of this application; Figure 3 This is a schematic diagram of the structure of the selection device for the camera condenser access node provided in a certain embodiment of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0020] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0021] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0022] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0023] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0024] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0025] See Figure 1 To address the problems of excessively long computation cycles and high simulation costs associated with existing technologies that rely on electromagnetic transient simulation for synchronous condenser site selection, an embodiment of the present invention provides a method for selecting a synchronous condenser access node, comprising: S1. Obtain the initial impedance data of the target AC system, the rated power of each converter bus in the target AC system, and several synchronous condenser location schemes; wherein, each synchronous condenser location scheme includes the weight parameters of each converter bus. Specifically, the initial impedance data of the target AC system needs to be obtained first, that is, the set of node impedance parameters and branch impedance parameters of the target AC system before the synchronous condenser is connected to the system; different synchronous condenser location schemes have different synchronous condenser access nodes, and each synchronous condenser location scheme is equipped with a preset weight coefficient for each converter bus to quantify the importance.

[0026] S2. For each synchronous condenser location scheme, the initial impedance data is adjusted according to the node impedance of the synchronous condenser access node in the current synchronous condenser location scheme to obtain the target impedance data. Specifically, assuming the target communication system connected to the synchronous condenser has a total of For each node, before the camera is connected, the node impedance matrix in the initial impedance data is... It can be represented as: (1) In the formula, Represents a node With nodes The initial impedance between.

[0027] In a preferred embodiment, the node impedance of the synchronous condenser access node includes the self-impedance of the synchronous condenser access node and the mutual impedance between the synchronous condenser access node and the remaining nodes in the target AC system. The step of adjusting the initial impedance data according to the node impedance of the camera access node in the current camera location scheme to obtain the target impedance data includes: Based on the self-impedance of the synchronous condenser access node in the current synchronous condenser location scheme and the mutual impedance between the synchronous condenser access node and the remaining nodes in the target AC system, the initial impedance data is adjusted to obtain the target impedance data. The initial impedance between any two nodes in the initial impedance data is adjusted using the following formula: (2) In the formula, Represents a node With nodes The initial impedance between; To adjust the camera access node Self-impedance; Indicates camera access node With nodes mutual impedance; Indicates camera access node With nodes mutual impedance; Specifically, by adding branches, at the synchronous condenser access node... Then, the initial impedance data is adjusted to obtain the target impedance data.

[0028] S3. Based on the target impedance data and the rated power of each converter bus, calculate the multi-infeed short-circuit ratio and multi-infeed interaction factor of each converter bus. In a preferred embodiment, the step of calculating the multi-infeed short-circuit ratio and multi-infeed interaction factor of each converter bus based on the target impedance data and the rated power of each converter bus includes: Based on the target impedance data, the multi-feed interaction factor between each converter bus in the target AC system is calculated. Based on the rated power of each converter bus and the target impedance data, the multi-feed short-circuit ratio of each converter bus in the target AC system is calculated. Specifically, the multi-infeed interaction factor is used to measure the degree of voltage coupling between converter stations, and can be defined as: When the converter bus By putting in three-phase symmetrical reactors, the converter bus... When the voltage drops by 1%, the converter bus Voltage change rate , can be represented as: (3) In the formula, For the converter bus before the three-phase symmetrical reactor is put into operation The effective value of the voltage; Indicates converter bus The change in voltage; Further: (4) In the formula, For converter bus With converter bus mutual impedance between For converter bus Self-impedance; As shown in the above formula, the larger the value of the multi-infeed interaction factor, the stronger the voltage coupling between the two converter buses; conversely, the smaller the value, the weaker the voltage coupling between the two converter buses. With converter bus Multi-feed interaction factors At that time, the voltage coupling between the two converter buses is approximately 0.

[0029] In actual engineering, synchronous condensers are connected to the converter bus or AC nodes with short electrical distances. When the synchronous condenser is connected to a node that is... At that time, the equivalent target communication system is as follows: Figure 2 As shown.

[0030] In steady state, the output current of the synchronous condenser can be considered to be 0. Therefore, the synchronous condenser can be connected to any node other than the node in which it is connected. voltage It can be represented as: (5) In the formula, Represents a node With nodes Mutual impedance between them; Represents a node The injected current; Represents a node With converter bus Mutual impedance between them; Indicates converter bus The initial injection current; After the converter bus is connected to the three-phase symmetrical reactor, the synchronous condenser is connected to the node. Voltage drop, any node voltage It can be represented as: (6) In the formula, For nodes Access node with condenser mutual impedance, To adjust the camera's output current; At a certain moment, if the synchronous condenser is represented by a voltage source model, then the output current of the synchronous condenser is: (7) In the formula, To adjust the camera access node The amount of voltage drop; To adjust the equivalent impedance of the branch where the camera access node is located; converter bus voltage It can be represented as: (8) In the formula, Indicates converter bus With nodes Mutual impedance between them; Indicates converter bus Self-impedance; Indicates converter bus Access node with condenser Mutual impedance between them; Indicates converter bus The corresponding equivalent load impedance; From equation (8), we can obtain the converter bus. The current flowing through a three-phase symmetrical reactor can be expressed as: (9) Substituting equation (9) into equation (5), we obtain the node after connecting the three-phase symmetrical reactor. The voltage is: (10) Subtracting equation (10) from equation (5), the node The voltage change is: (11) From equation (11), we can obtain the camera access node. The voltage change is: (12) By combining equations (12) and (7), we can obtain: (13) Substituting equation (13) into equation (11), we get: (14) As can be seen from the definition, (15) In a preferred embodiment, calculating the multi-feed interaction factor between each converter bus in the target AC system based on the target impedance data includes: The multi-feedback interaction factor is calculated using the following formula: (16) In the formula, Indicates converter bus With converter bus Multiple feed-in interaction factors between them; Indicates converter bus With converter bus mutual impedance; This represents the equivalent impedance of the branch where the camera module access node is located; Indicates converter bus Access node with condenser mutual impedance; Indicates converter bus Access node with condenser mutual impedance; Indicates converter bus Self-impedance.

[0031] In a preferred embodiment, calculating the multi-infeed short-circuit ratio of each converter bus in the target AC system based on the target impedance data includes: The multi-feed short-circuit ratio is calculated using the following formula: (17) In the formula, Indicates the multi-feed short-circuit ratio; Indicates camera access node With converter bus mutual impedance; Indicates the total number of converter buses; Indicates camera access node With converter bus mutual impedance; Indicates converter bus Rated power; Indicates converter bus Rated power; Schematic representation: For a single converter bus, the short-circuit ratio can be defined as: the short-circuit capacity of the converter station. Rated power of the converter bus The ratio; reference voltage Take the rated value of the converter bus voltage. Reference power Take as rated DC power The short-circuit ratio (SCR) of a single converter bus can be expressed as: (18) In the formula, The equivalent impedance of the target AC system, This is the reference value for impedance. This represents the per-unit value of the impedance; Although the above-mentioned short-circuit ratio index for a single DC line is not applicable to multi-infeed DC systems, the definition of the single-line short-circuit ratio can still be used; therefore, the converter bus The corresponding multi-infeed short-circuit ratio can be defined as: (19) The multiple infeed short-circuit ratio (MISCR) measures the voltage support capability of the target AC system. The larger the MISCR, the stronger the target AC system, the smaller the voltage drop of the converter bus during a fault, and the more stable the system. The smaller the MISCR, the weaker the AC system, the larger the voltage drop of the converter bus during a fault, and the greater the risk of commutation failure. Substituting equation (2) into equation (19), we can obtain the converter bus. The expression for the multi-feed short-circuit ratio is given by equation (16).

[0032] S4. Based on the target impedance data, calculate the ratio of the impedance between each converter bus and the synchronous condenser access node. Specifically, the goal of connecting a synchronous condenser is to reduce the risk of simultaneous or successive commutation failures in a multi-infeed DC system; since the multi-infeed interaction factor needs to show a decreasing trend after the synchronous condenser is connected, and its change... The impedance should not be less than 0. Based on the target impedance data, the ratio of the impedance between each converter bus and the synchronous condenser access node is calculated. Furthermore, in the calculation of the objective function, the camera access node is adjusted. The following conditions must be met: (20) S5. Determine whether the multi-infeed interaction factor between each converter bus is not greater than the ratio. If so, calculate the total objective function value of the current synchronous condenser location scheme based on the target impedance data, the weight parameters of each converter bus, the rated power, the multi-infeed short-circuit ratio and the multi-infeed interaction factor. If not, discard the current synchronous condenser location scheme. Indicatively, it is determined whether the multi-infeed interaction factor among each converter bus is not greater than the ratio. If so, the total objective function value of the current synchronous condenser location scheme is calculated based on the target impedance data, the weight parameters of each converter bus, the rated power, the multi-infeed short-circuit ratio, and the multi-infeed interaction factor. In a preferred embodiment, the weight parameters of each converter bus are determined in the following manner: Based on the node impedance of the three-phase symmetrical reactor access node in the target impedance data, the voltage coupling factor of each converter bus is calculated. The number of converter buses whose voltage coupling factor exceeds the corresponding critical voltage coupling factor is counted and used as the first number; Based on the total number of converter buses in the target AC system and the first quantity, determine the weight parameters of each converter bus; Specifically, assuming at any node Connect a three-phase symmetrical reactor, node The voltage change is Converter bus The voltage change is The voltage coupling factor is defined as the converter bus. voltage change With nodes Voltage change The ratio of voltage coupling factor It can be represented as: ; (twenty one) In the formula, Represents a node With converter bus mutual impedance; For nodes Self-impedance; When node When a short circuit fault occurs, the converter bus The voltage dropped The switching angle of the converter station can be expressed as: ; (twenty two) In the formula, For converter bus The current; For commutation reactance; Before the fault, the converter bus Line voltage; Converter station The leading trigger angle; Converter station The transformer turns ratio; From equation (22), we can see that the node When the voltage drops, the converter station The switching angle decreases, converter station There is a risk of commutation failure; especially when the node... When the voltage drops to 0, the converter station The cutoff angle is the smallest, which can be expressed as: ; (twenty three) In the formula, Indicates the node before the failure The voltage.

[0033] when At that time, converter station Commutation failure may occur; critical voltage coupling factor Represented as: ; (twenty four) If the converter bus The voltage coupling factor exceeds the critical value, i.e. Under the most severe failure of the target communication system, i.e., node In the event of a complete voltage drop, the converter station Commutation failure will occur, therefore it is used in measurable extreme cases (all voltages at node m drop), for each converter bus. Corresponding converter station The risk of commutation failure; Therefore, the number of converter buses whose voltage coupling factors exceed the corresponding critical voltage coupling factor is counted as the first number. The first number is divided by the total number of converter buses in the target AC system to calculate the first weight value. The first weight value (0-1) is assigned to each converter bus whose voltage coupling factor exceeds the corresponding critical voltage coupling factor. The remaining converter buses whose voltage coupling factors do not exceed the corresponding critical voltage coupling factor are assigned a second weight value (second weight value = 1 - first weight value). Thus, the weight parameters of each converter bus are determined.

[0034] In a preferred embodiment, the total objective function value includes a first objective function value and a second objective function value; The overall objective function value of the current synchronous condenser location scheme is calculated based on the target impedance data, the weight parameters of each converter bus, the rated power, the multi-infeed short-circuit ratio, and the multi-infeed interaction factor, including: The first objective function value is calculated based on the target impedance data, the weight parameters of each converter bus, and the multi-feed interaction factor. The second objective function value is calculated based on the target impedance data, the weight parameters of each converter bus, the rated power, and the multi-infeed short-circuit ratio. The total objective function value of the current synchronous condenser location scheme is calculated based on the first objective function value and the second objective function value.

[0035] In a preferred embodiment, calculating the first objective function value based on the target impedance data, the weight parameters of each converter bus, and the multi-feed interaction factor includes: The value of the first objective function is calculated using the following formula: (25) In the formula, This represents the value of the first objective function; Indicates converter bus Weight parameters; In a preferred embodiment, the step of calculating the second objective function value based on the target impedance data, the weight parameters of each converter bus, the rated power, and the multi-infeed short-circuit ratio includes: The value of the second objective function is calculated using the following formula: (26) In the formula, Indicates camera access node With converter bus mutual impedance; Specifically, the mathematical model is composed of and It consists of two objective functions, the specific expressions of which are as follows: (27) Each objective function is related to the target impedance data, the camera access node, and the camera branch impedance data. Furthermore, the two objective functions will change differently depending on the camera access point. Therefore, the resulting mathematical model conforms to the characteristics of a multi-objective function. The range standardization method can be used to standardize the two function values ​​and then add them together, transforming it into a single-objective function for solution. (28) In the formula, To adjust the camera access node; and The function value after range standardization can be expressed as: (29) In the formula, and The maximum value corresponding to each objective function. and This represents the minimum value corresponding to each objective function.

[0036] After range standardization, the two objective functions have no dimensions. If the two objective functions are considered to be equally important, the two function values ​​can be directly added together.

[0037] S6. Select the synchronous condenser location scheme with the highest total objective function value as the target synchronous condenser location scheme, and take the node connected to the synchronous condenser in the target synchronous condenser location scheme as the final access node of the synchronous condenser. Specifically, by calling the Gurobi toolkit to solve equations (28)-(29), the camera location scheme with the highest total objective function value can be selected as the target camera location scheme, and the node connected to the camera in the target camera location scheme can be used as the final access node of the camera.

[0038] See Figure 2 This invention provides a device for selecting a synchronous condenser access node, comprising: a data acquisition module for acquiring initial impedance data of a target AC system, rated power of each converter bus in the target AC system, and several synchronous condenser location schemes; wherein each synchronous condenser location scheme includes weight parameters for each converter bus. The data adjustment module is used to adjust the initial impedance data according to the node impedance of the synchronous condenser access node in the current synchronous condenser location scheme for each synchronous condenser location scheme, so as to obtain the target impedance data. The first calculation module is used to calculate the multi-infeed short-circuit ratio and multi-infeed interaction factor of each converter bus based on the target impedance data and the rated power of each converter bus. The second calculation module is used to calculate the ratio of the impedance between each converter bus and the synchronous condenser access node based on the target impedance data. The scheme selection module is used to determine whether the multi-infeed interaction factor between each converter bus is not greater than the ratio. If so, the total objective function value of the current synchronous condenser location scheme is calculated based on the target impedance data, the weight parameters of each converter bus, the rated power, the multi-infeed short-circuit ratio and the multi-infeed interaction factor. If not, the current synchronous condenser location scheme is discarded. The access node determination module is used to select the camera condenser location scheme with the highest total objective function value as the target camera condenser location scheme, and to select the node to which the camera condenser is connected in the target camera condenser location scheme as the final access node of the camera condenser.

[0039] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for selecting a camera access node, characterized in that, include: The initial impedance data of the target AC system, the rated power of each converter bus in the target AC system, and several synchronous condenser location schemes are obtained; wherein, each synchronous condenser location scheme includes weight parameters for each converter bus. For each synchronous condenser location scheme, the initial impedance data is adjusted according to the node impedance of the synchronous condenser access node in the current synchronous condenser location scheme to obtain the target impedance data; Based on the target impedance data and the rated power of each converter bus, the multi-infeed short-circuit ratio and multi-infeed interaction factor of each converter bus are calculated. Based on the target impedance data, the ratio of the impedance between each converter bus and the synchronous condenser access node is calculated. Determine whether the multi-infeed interaction factor between each converter bus is not greater than the ratio. If so, calculate the total objective function value of the current synchronous condenser location scheme based on the target impedance data, the weight parameters of each converter bus, the rated power, the multi-infeed short-circuit ratio, and the multi-infeed interaction factor. If not, discard the current synchronous condenser location scheme. The synchronous condenser location scheme with the highest overall objective function value is selected as the target synchronous condenser location scheme, and the node connected to the synchronous condenser in the target synchronous condenser location scheme is taken as the final access node of the synchronous condenser.

2. The method for selecting a synchronous condenser access node as described in claim 1, characterized in that, The node impedance of the synchronous condenser access node includes the self-impedance of the synchronous condenser access node and the mutual impedance between the synchronous condenser access node and the remaining nodes in the target AC system. The step of adjusting the initial impedance data according to the node impedance of the camera access node in the current camera location scheme to obtain the target impedance data includes: Based on the self-impedance of the synchronous condenser access node in the current synchronous condenser location scheme and the mutual impedance between the synchronous condenser access node and the remaining nodes in the target AC system, the initial impedance data is adjusted to obtain the target impedance data; wherein, the initial impedance between any two nodes in the initial impedance data is adjusted using the following formula: ； In the formula, Represents a node With nodes The initial impedance between; To adjust the camera access node Self-impedance; Indicates the camera access node With nodes mutual impedance; Indicates the camera access node With nodes The mutual impedance.

3. The method for selecting a synchronous condenser access node as described in claim 2, characterized in that, The calculation of the multi-infeed short-circuit ratio and multi-infeed interaction factor for each converter bus, based on the target impedance data and the rated power of each converter bus, includes: Based on the target impedance data, the multi-feed interaction factor between each converter bus in the target AC system is calculated. Based on the rated power of each converter bus and the target impedance data, the multi-feed short-circuit ratio of each converter bus in the target AC system is calculated.

4. The method for selecting a synchronous condenser access node as described in claim 3, characterized in that, The step of calculating the multi-feed interaction factor between each converter bus in the target AC system based on the target impedance data includes: The multi-feedback interaction factor is calculated using the following formula: ； In the formula, Indicates converter bus With converter bus Multiple feed-in interaction factors between them; Indicates converter bus With converter bus mutual impedance; This represents the equivalent impedance of the branch where the camera module access node is located; Indicates converter bus Access node with condenser mutual impedance; Indicates converter bus Access node with condenser mutual impedance; Indicates converter bus Self-impedance.

5. The method for selecting a synchronous condenser access node as described in claim 4, characterized in that, The step of calculating the multi-infeed short-circuit ratio of each converter bus in the target AC system based on the target impedance data includes: The multi-feed short-circuit ratio is calculated using the following formula: ； In the formula, Indicates the multi-feed short-circuit ratio; Indicates the camera access node With converter bus mutual impedance; Indicates the total number of converter buses; Indicates the camera access node With converter bus mutual impedance; Indicates converter bus Rated power; Indicates converter bus Rated power.

6. The method for selecting a synchronous condenser access node as described in claim 1, characterized in that, The total objective function value includes the first objective function value and the second objective function value; The overall objective function value of the current synchronous condenser location scheme is calculated based on the target impedance data, the weight parameters of each converter bus, the rated power, the multi-infeed short-circuit ratio, and the multi-infeed interaction factor, including: The first objective function value is calculated based on the target impedance data, the weight parameters of each converter bus, and the multi-feed interaction factor. The second objective function value is calculated based on the target impedance data, the weight parameters of each converter bus, the rated power, and the multi-infeed short-circuit ratio. The total objective function value of the current synchronous condenser location scheme is calculated based on the first objective function value and the second objective function value.

7. The method for selecting a synchronous condenser access node as described in claim 6, characterized in that, The calculation of the first objective function value based on the target impedance data, the weight parameters of each converter bus, and the multi-feed interaction factor includes: The value of the first objective function is calculated using the following formula: ； In the formula, This represents the value of the first objective function; Indicates converter bus The weight parameters.

8. The method for selecting a synchronous condenser access node as described in claim 7, characterized in that, The calculation of the second objective function value based on the target impedance data, the weight parameters of each converter bus, the rated power, and the multi-infeed short-circuit ratio includes: The value of the second objective function is calculated using the following formula: ； In the formula, Indicates the camera access node With converter bus The mutual impedance.

9. The method for selecting a synchronous condenser access node as described in claim 8, characterized in that, The weight parameters of each converter bus are determined in the following manner: Based on the node impedance of the three-phase symmetrical reactor access node in the target impedance data, the voltage coupling factor of each converter bus is calculated. The number of converter buses whose voltage coupling factor exceeds the corresponding critical voltage coupling factor is counted and used as the first number; The weight parameters of each converter bus are determined based on the total number of converter buses in the target AC system and the first quantity.

10. A device for selecting a camera access node, characterized in that, include: The data acquisition module is used to acquire the initial impedance data of the target AC system, the rated power of each converter bus in the target AC system, and several synchronous condenser location schemes; wherein, each synchronous condenser location scheme includes the weight parameters of each converter bus. The data adjustment module is used to adjust the initial impedance data according to the node impedance of the synchronous condenser access node in the current synchronous condenser location scheme for each synchronous condenser location scheme, so as to obtain the target impedance data. The first calculation module is used to calculate the multi-infeed short-circuit ratio and multi-infeed interaction factor of each converter bus based on the target impedance data and the rated power of each converter bus. The second calculation module is used to calculate the ratio of the impedance between each converter bus and the synchronous condenser access node based on the target impedance data. The scheme selection module is used to determine whether the multi-infeed interaction factor between each converter bus is not greater than the ratio. If so, the total objective function value of the current synchronous condenser location scheme is calculated based on the target impedance data, the weight parameters of each converter bus, the rated power, the multi-infeed short-circuit ratio and the multi-infeed interaction factor. If not, the current synchronous condenser location scheme is discarded. The access node determination module is used to select the camera condenser location scheme with the highest total objective function value as the target camera condenser location scheme, and to select the node to which the camera condenser is connected in the target camera condenser location scheme as the final access node of the camera condenser.

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