CN113381445B - A method and system for optimal configuration of a condenser for suppressing transient overvoltage of new energy sources - Google Patents

Abstract

The invention discloses a method and system for optimizing the configuration of a condenser to suppress the transient overvoltage of a new energy source, including: calculating the new energy multi-station short-circuit ratio of each new energy connected to a target AC-DC hybrid power grid and the target The transient overvoltage of each new energy source when the AC/DC hybrid power grid is faulty; Determine the short-circuit ratio threshold of new energy multi-site stations; configure a condenser on the low-voltage side of the new energy grid-connected point with the smallest new energy multi-site short-circuit ratio, and recalculate the new energy multi-site short-circuit ratio of each new energy source; when each new energy When the new energy multi-station short-circuit ratio of the energy source is greater than or equal to the new energy multi-station short-circuit ratio threshold, recalculate the transient overvoltage of each new energy; when the transient overvoltage of each new energy is less than or equal to the transient overvoltage When the voltage threshold is reached, determine that the current configuration scheme of the condenser is the optimal scheme for the configuration of the condenser.

Description

A method and system for optimal configuration of a condenser for suppressing transient overvoltage of new energy sources

technical field

The present invention relates to the technical field of multi-new energy station access AC-DC hybrid power grid planning and operation control, and more specifically, relates to a method and system for optimizing the configuration of a condenser for suppressing transient overvoltage of new energy sources.

Background technique

Large-capacity UHV AC-DC long-distance power transmission is an important measure to solve large-scale new energy base transmission and prevent air pollution. A series of challenges, such as the self-oscillation and overvoltage problems caused by the large-scale connection of new energy generators to weak power grids, have seriously restricted the security of the power grid and the delivery of new energy. When commutation failure and DC blocking fault occur in the DC system, there will be a stage of excess reactive power in the converter station at the sending end, which will lead to an increase in the voltage of the AC busbar at the sending end and overvoltage. In Northwest my country, a large amount of wind power is collected at the DC sending end, and the transient voltage rise at the sending end may be transmitted to nearby wind farms, causing high-voltage disconnection of wind turbines, which will pose great challenges to the safe and stable operation of the power grid.

As a kind of synchronous motor, the condenser can effectively increase the short-circuit capacity of the system, enhance the voltage strength of the power grid, and improve the voltage support ability after the power grid has a fault disturbance, thereby reducing voltage fluctuations during a fault and suppressing overvoltage. Since the condenser is a rotating component, it is limited by factors such as one-time investment, maintenance cost, and site selection. In the planning stage, it is necessary to consider the detailed configuration of the condenser; If the voltage is disconnected from the grid in a large area, it is also necessary to consider installing a condenser as an effective measure to improve the strength of the system.

In the AC-DC hybrid power grid, the concentrator generally adopts the configuration method of centralized access to the DC commutation bus to provide the necessary reactive voltage support for safe and stable operation after grid fault disturbance. With the access of multiple new energy stations in the AC/DC hybrid power grid, in order to enhance the strength of the multi-new energy station access system, in addition to configuring centralized condensers in the converter stations, different voltage levels of the new energy stations are paralleled. The busbars of outlets or collection stations also need to be equipped with distributed condensers accordingly. However, there is no engineering and practical configuration process for condensers at this stage, and it is urgent to carry out research on the optimal configuration of condensers in new energy stations.

Contents of the invention

The present invention proposes a method and system for optimal configuration of a condenser for suppressing transient overvoltages of new energy sources, so as to solve the problem of how to optimize the configuration of condensers for new energy stations.

In order to solve the above problems, according to one aspect of the present invention, a method for optimal configuration of a condenser for suppressing transient overvoltage of new energy sources is provided, the method comprising:

Step 1, calculating the new energy multi-site short-circuit ratio of each new energy connected to the target AC-DC hybrid grid and the transient overvoltage of each new energy when the target AC-DC hybrid grid fails;

Step 2, when the transient overvoltage of new energy is greater than the preset transient overvoltage threshold, determine the new energy multi-site short-circuit ratio threshold according to the multi-site short-circuit ratio and transient overvoltage of each new energy;

Step 3. Configure a preset number of condensers on the low-voltage side of the grid-connected point of the new energy with the smallest short-circuit ratio of new energy multi-site stations, and recalculate the short-circuit ratio of new energy multi-site stations for each new energy source;

Step 4, when the new energy multi-station short-circuit ratio of each new energy is greater than or equal to the new energy multi-station short-circuit ratio threshold, recalculate the transient overvoltage of each new energy;

Step 5, when the transient overvoltage of each new energy source is less than or equal to the preset transient overvoltage threshold, determine that the current condenser configuration scheme is the optimal scheme for condenser configuration.

Preferably, the determination of the new energy multi-site short-circuit ratio threshold according to the multi-site short-circuit ratio and transient overvoltage of each new energy source includes:

Select the short-circuit ratio of multiple stations corresponding to the new energy with the smallest absolute value of the difference between the transient overvoltage and the preset transient overvoltage threshold among the new energy sources whose transient overvoltage is less than the preset transient overvoltage threshold as the new energy Multi-site short-circuit ratio threshold.

Preferably, wherein said method further comprises:

When the new energy multi-station short-circuit ratio of the new energy is less than the new energy multi-station short-circuit ratio threshold, re-determine the new energy with the smallest new energy multi-station short-circuit ratio, and return to step 3.

Preferably, wherein said method further comprises:

When the transient overvoltage of new energy is greater than the preset transient overvoltage threshold, configure a preset number of condensers on the low-voltage side of the grid-connected point of the new energy with the largest transient overvoltage, and return to step 4 to recalculate each The transient overvoltage of new energy sources, until the transient overvoltage of each new energy source is less than or equal to the preset transient overvoltage threshold, enter step 5.

Preferably, the preset transient overvoltage threshold is 1.3p.u.

According to another aspect of the present invention, a condenser optimal configuration system for suppressing the transient overvoltage of new energy sources is provided, and the system includes:

A calculation unit, used to calculate the new energy multi-site short-circuit ratio of each new energy connected to the target AC-DC hybrid grid and the transient overvoltage of each new energy when the target AC-DC hybrid grid fails;

The multi-station short-circuit ratio threshold determination unit is used to determine the new energy source according to the multi-station short-circuit ratio and transient overvoltage of each new energy source when the transient overvoltage of the new energy source is greater than the preset transient overvoltage threshold value. Multi-station short-circuit ratio threshold;

The first configuration unit is used to configure a preset number of condensers on the low-voltage side of the new energy grid-connected point with the smallest new energy multi-site short-circuit ratio, and recalculate the new energy multi-site short-circuit ratio of each new energy;

The transient overvoltage updating unit is used to recalculate the transient overvoltage of each new energy when the new energy multi-station short-circuit ratio of each new energy is greater than or equal to the new energy multi-station short-circuit ratio threshold;

The optimal scheme for condenser configuration determination unit is used to determine that the current condenser configuration scheme is the optimal scheme for condenser configuration when the transient overvoltage of each new energy source is less than or equal to the preset transient overvoltage threshold.

Preferably, the multi-site short-circuit ratio threshold determination unit determines the new energy multi-site short-circuit ratio threshold according to the multi-site short-circuit ratio and transient overvoltage of each new energy source, including:

Select the short-circuit ratio of multiple stations corresponding to the new energy with the smallest absolute value of the difference between the transient overvoltage and the preset transient overvoltage threshold among the new energy sources whose transient overvoltage is less than the preset transient overvoltage threshold as the new energy Multi-site short-circuit ratio threshold.

Preferably, wherein said system also includes:

The update unit is used to re-determine the new energy with the smallest short-circuit ratio of the new energy multi-station when the new energy multi-station short-circuit ratio of the new energy is less than the threshold value of the new energy multi-station short-circuit ratio, and enter the first hive.

Preferably, wherein said system also includes:

The second configuration unit is used to configure a preset number of condensers on the low-voltage side of the grid-connected point of the new energy source with the largest transient overvoltage when the transient overvoltage of the new energy source is greater than the preset transient overvoltage threshold, and Enter the transient overvoltage update unit to recalculate the transient overvoltage of each new energy until the transient overvoltage of each new energy is less than or equal to the preset transient overvoltage threshold, then enter the configuration of the controller Optimal solution determination unit.

Preferably, in the multi-station short circuit ratio threshold determining unit, the preset transient overvoltage threshold is 1.3p.u.

The present invention provides a method and system for optimizing the configuration of the inverter to suppress the transient overvoltage of new energy sources. According to the short-circuit ratio and transient overvoltage of each new energy source, the multi-site short-circuit ratio threshold of the new energy source is determined. In the new energy Configure the preset number of condensers on the low-voltage side of the new energy grid-connected point with the smallest energy multi-site short-circuit ratio, and recalculate the new energy multi-site short-circuit ratio of each new energy; when each new energy multi-site new energy When the short-circuit ratio is greater than or equal to the short-circuit ratio threshold of multiple new energy stations, recalculate the transient overvoltage of each new energy; when the transient overvoltage of each new energy is less than or equal to the preset transient overvoltage threshold, It is determined that the current condenser configuration scheme is the optimal scheme for condenser configuration; the present invention can maximize the configuration effect of synchronous condensers while minimizing the configuration capacity of synchronous condensers, obtain better economic efficiency, ensure the safe grid connection of new energy sources, and improve the power grid Voltage strength, to prevent new energy power generation equipment from being disconnected from the grid in a large area caused by the terminal voltage of the machine exceeding its voltage protection setting.

Description of drawings

A more complete understanding of the exemplary embodiments of the present invention can be had by referring to the following drawings:

FIG. 1 is a flow chart of a method 100 for optimal configuration of a condenser for suppressing transient overvoltage of new energy sources according to an embodiment of the present invention;

Fig. 2 is a schematic diagram of a multi-new energy station access system including a plurality of new energy stations according to an embodiment of the present invention;

Fig. 3 is a flow chart of determining a configuration scheme of a camera according to an embodiment of the present invention;

Fig. 4 is a configuration diagram of a power grid for configuration and testing of a condenser according to an embodiment of the present invention;

Fig. 5 is a schematic diagram of transient overvoltage and new energy multi-site short-circuit ratio according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a condenser optimal configuration system 600 for suppressing transient overvoltage of new energy sources according to an embodiment of the present invention.

Detailed ways

Exemplary embodiments of the present invention will now be described with reference to the drawings; however, the present invention may be embodied in many different forms and are not limited to the embodiments described herein, which are provided for the purpose of exhaustively and completely disclosing the present invention. invention and fully convey the scope of the invention to those skilled in the art. The terms used in the exemplary embodiments shown in the drawings do not limit the present invention. In the figures, the same units/elements are given the same reference numerals.

Unless otherwise specified, the terms (including scientific and technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it can be understood that terms defined by commonly used dictionaries should be understood to have consistent meanings in the context of their related fields, and should not be understood as idealized or overly formal meanings.

FIG. 1 is a flow chart of a method 100 for optimal configuration of a condenser for suppressing transient overvoltage of new energy sources according to an embodiment of the present invention. As shown in Figure 1, the optimal configuration method of the condenser for suppressing the transient overvoltage of the new energy provided by the embodiment of the present invention can maximize the configuration effect of the synchronous condenser and minimize the configuration capacity of the synchronous condenser to obtain better economy. Ensure the safe grid connection of new energy, increase the voltage strength of the grid, and prevent the occurrence of large-scale disconnection of new energy stations caused by the terminal voltage of new energy power generation equipment exceeding its voltage protection setting. According to the embodiment of the present invention, the optimal configuration method 100 for suppressing the transient overvoltage of new energy sources starts from step 101, and at step 101, calculates the new energy multi-site stations of each new energy connected to the target AC/DC hybrid power grid The short-circuit ratio and the transient overvoltage of each new energy source when the target AC-DC hybrid grid fails.

In step 102, when the transient overvoltage of new energy is greater than the preset transient overvoltage threshold, the new energy multi-site short-circuit ratio threshold is determined according to the multi-site short-circuit ratio and transient overvoltage of each new energy.

Preferably, the determination of the new energy multi-site short-circuit ratio threshold according to the multi-site short-circuit ratio and transient overvoltage of each new energy source includes:

Select the short-circuit ratio of multiple stations corresponding to the new energy with the smallest absolute value of the difference between the transient overvoltage and the preset transient overvoltage threshold among the new energy sources whose transient overvoltage is less than the preset transient overvoltage threshold as the new energy Multi-site short-circuit ratio threshold.

Preferably, the preset transient overvoltage threshold is 1.3p.u.

In the present invention, an AC/DC hybrid power grid connected to multiple new energy stations is selected as the target power grid as required. As shown in Figure 2, it is a schematic diagram of a multi-new energy station access system including n new energy stations, where the new energy multi-site short-circuit ratio (MRSCR) is defined according to the formula:

Among them, U _i and U _j are the grid-connected point voltages of new energy stations/power generation units i and j respectively; U _Ni is the nominal voltage of the grid-connected points of new energy stations/power generation units i; Z _eqij is the new energy grid-connected point voltage Elements in row i and column j of the equivalent impedance matrix Z _eq of the AC grid at the busbar.

As shown in Figure 3, in the present invention, it is necessary to determine that the selected multi-new energy stations are connected to the AC-DC hybrid power grid, and the new energy multi-site stations required to ensure that the transient overvoltage of the new energy does not exceed the limit Short circuit ratio critical value MRSCR _Gmin . Specifically, it includes: first, calculate the transient overvoltage of each new energy and the short circuit Then, if there is no transient overvoltage of new energy in the grid that is greater than the preset transient overvoltage threshold, it is determined that there is no need to configure a distributed condenser in the grid; if there is a transient overvoltage of new energy in the grid that exceeds Transient overvoltage threshold, select the new energy corresponding to the new energy with the smallest absolute value of the difference between the transient overvoltage and the preset transient overvoltage threshold among the new energy sources whose transient overvoltage is less than the preset transient overvoltage threshold The station short-circuit ratio is the new energy multi-site short-circuit ratio threshold MRSCR _Gmin . Among them, MRSCR _Gmin is considered to be the critical value of the new energy multi-site short-circuit ratio that can keep the new energy transient overvoltage from exceeding the limit. Among them, for power grids with weak AC grids, new energy may have overvoltage problems, and its overvoltage limit needs to be set in conjunction with the overvoltage off-grid requirements of actual new energy equipment. The default value of the overvoltage off-grid limit for general It is 1.3pu, so the preset transient overvoltage threshold is set to 1.3pu.

In step 103, configure a preset number of condensers on the low-voltage side of the new energy grid-connected point with the smallest new energy multi-station short-circuit ratio, and recalculate the new energy multi-station short-circuit ratio of each new energy.

Preferably, wherein said method further comprises:

When the new energy multi-site short-circuit ratio of new energy exists is less than the new energy multi-site short-circuit ratio threshold, re-determine the new energy with the smallest new energy multi-site short-circuit ratio, and return to step 103 .

In step 104, when the new energy multi-station short-circuit ratio of each new energy is greater than or equal to the new energy multi-station short-circuit ratio threshold, recalculate the transient overvoltage of each new energy.

As shown in Figure 3, in the present invention, first select the new energy source with the smallest short-circuit ratio of multiple stations, and configure a preset number of condensers on the low-voltage side of the grid-connected point of the new energy source with the smallest short-circuit ratio , and then recalculate the new energy multi-station short-circuit ratio of each new energy, and judge whether the new energy multi-station short-circuit ratio MRSCR _G of each new energy G satisfies MRSCR _G ≥ MRSCR _Gmin , and if so, go directly to step 104 Recalculate the transient overvoltage of each new energy; on the contrary, if there is a new energy multi-site short-circuit ratio of a new energy that does not meet MRSCR _G ≥ MRSCR _Gmin , it is necessary to continue to configure the condenser to increase the short-circuit ratio and re-determine the new energy The new energy with the smallest short-circuit ratio of the multi-site station, and return to step 103. Configure a preset number of condensers on the low-voltage side of the grid-connected point of the new energy with the smallest short-circuit ratio of the new energy multi-site station, until the new energy multi-field of each new energy G When the station short-circuit ratio MRSCR _G satisfies MRSCR _G ≥ MRSCR _Gmin , enter step 104 to recalculate the transient overvoltage of each new energy source.

In the present invention, the quantity and capacity of the condensers added each time are determined according to actual needs. In view of the fact that the goal of optimizing the configuration of synchronous condensers is to maximize the configuration effect of synchronous condensers and minimize the configuration capacity of synchronous condensers, that is, to obtain better economy. Therefore, the present invention configures a 50Mvar distributed condenser on the low-voltage side of the grid-connected point of the new energy multi-site short-circuit ratio with the smallest new energy.

In step 105, when the transient overvoltage of each new energy source is less than or equal to the preset transient overvoltage threshold, it is determined that the current condenser configuration scheme is the optimal scheme for condenser configuration.

Preferably, wherein said method further comprises:

When the transient overvoltage of new energy is greater than the preset transient overvoltage threshold, configure a preset number of condensers on the low-voltage side of the grid-connected point of the new energy with the largest transient overvoltage, and return to step 104 to recalculate each The transient overvoltage of the new energy source, until the transient overvoltage of each new energy source is less than or equal to the preset transient overvoltage threshold, enter step 105 .

In the present invention, after configuring the condenser so that the new energy multi-site short-circuit ratio of each new energy satisfies MRSCR _G ≥ MRSCR _Gmin , due to the influence of fault location and other factors, there may still be some new energy, although the short-circuit ratio is high However, there are still overvoltages that exceed the limit. Therefore, it is necessary to calculate transient overvoltages at these nodes, and configure condensers on the low-voltage side of the grid-connected point of new energy sources with the largest transient overvoltages until all new energy sources None of the transient overvoltages exceeds the transient overvoltage threshold.

In the present invention, when the transient overvoltage of each new energy source is less than or equal to the preset transient overvoltage threshold, it is directly determined that the current condenser configuration scheme is the optimal scheme for condenser configuration. When the transient overvoltage of new energy is greater than the preset transient overvoltage threshold, configure a preset number of condensers on the low-voltage side of the grid-connected point of the new energy with the largest transient overvoltage, and return to step 104 to recalculate each The transient overvoltage of new energy sources, until the transient overvoltage of each new energy source is less than or equal to the preset transient overvoltage threshold, enter step 105, and determine that the current configuration scheme of the condenser is the optimal scheme for the configuration of the condenser.

Fig. 4 is a structural diagram of a configuration test grid for a condenser according to an embodiment of the present invention. As shown in Figure 4, the system is a provincial-level power grid in western my country, with a main grid voltage level of 750kV, including two main new energy bases, namely, the new energy base in the province and the new energy base near the DC area; the power grid passes through 2 The provincial power grid is connected to other regional power grids through UHV DC channels. The main conventional units in the power grid are far away from the new energy base, more than 300 kilometers. For the system in Figure 4, under the condition of new energy giants, the minimum short-circuit ratio of the new energy machine end of the whole network is 1.117. At this time, the fault of the 330kV line N-1 at the sending end is calculated, and the maximum transient overvoltage of the new energy at this time can reach 1.476p.u.

The existing method uses direct calculation of overvoltage, and configures distributed condensers at the highest point of overvoltage. After 20 calculations, it can be obtained that 20 condensers can be configured in a typical power grid to suppress the transient overvoltage of new energy sources to below 1.3p.u.

Using the method of the present invention, the first step is to calculate the short-circuit ratio corresponding to the overvoltage 1.3 p.u. in the grid, and the calculation results are shown in FIG. 5 . It can be seen from the calculation results that the short-circuit ratio corresponding to the new energy transient overvoltage 1.3p.u. is about 1.4, so the first step is to configure distributed condensers to make the minimum short-circuit ratio of the new energy multi-site station reach 1.4. The second step is to increase the short-circuit ratio of new energy multi-site stations by configuring condensers. By configuring 10 distributed condensers, after deploying 10 distributed condensers, the highest transient overvoltage value of new energy at this time can be obtained by calculation. It is 1.344p.u., so at this time, start to configure the condenser at the position with the highest transient overvoltage of the new energy. The third step is to configure a condenser at the highest point of the transient overvoltage of the new energy. After adding 4 condensers, the transient overvoltage of the new energy in the DC near area can be suppressed below 1.3p.u.

Through the comparison of the calculation results of the two methods, it can be seen that: 1. The number of condensers required to configure the condenser directly according to the calculation result of the overvoltage is more, and the number of condensers required to configure the condenser based on the calculation result of the short circuit ratio is less, which is more economical. 2. The method of configuring the condenser based on the short-circuit ratio is more efficient and easier to calculate.

The invention aims at the problem of transient overvoltage of new energy power generation equipment caused by large-scale new energy access to the AC-DC hybrid power grid. Under the condition of ensuring a certain scale of new energy access, the total capacity of the required inverter is the least. The configuration scheme prevents new energy from being disconnected from the grid due to large-scale oscillation due to overvoltage, and at the same time greatly improves the new energy acceptance capacity of the power grid; it can be applied to various new energy stations such as wind farms and photovoltaic power stations, covering a wide range, realizing convenience, The effect is remarkable.

FIG. 6 is a schematic structural diagram of a condenser optimal configuration system 600 for suppressing transient overvoltage of new energy sources according to an embodiment of the present invention. As shown in Fig. 6, the optimal configuration system 600 of the condenser for suppressing the transient overvoltage of new energy provided by the embodiment of the present invention includes: a calculation unit 601, a multi-site short-circuit ratio threshold determination unit 602, a first configuration unit 603, a temporary The state overvoltage update unit 604 and the optimal configuration scheme determination unit 605 of the condenser.

Preferably, the calculation unit 601 is used to calculate the new energy multi-site short-circuit ratio of each new energy connected to the target AC-DC hybrid grid and the temporary short-circuit ratio of each new energy when the target AC-DC hybrid grid fails. state overvoltage.

Preferably, the multi-station short-circuit ratio threshold determining unit 602 is used to determine the multi-station short-circuit ratio and the transient Determine the short-circuit ratio threshold of new energy multi-site stations based on the state overvoltage.

Preferably, the multi-site short-circuit ratio threshold determination unit 602 determines the new energy multi-site short-circuit ratio threshold according to the multi-site short-circuit ratio and transient overvoltage of each new energy source, including:

Select the short-circuit ratio of multiple stations corresponding to the new energy with the smallest absolute value of the difference between the transient overvoltage and the preset transient overvoltage threshold among the new energy sources whose transient overvoltage is less than the preset transient overvoltage threshold as the new energy Multi-site short-circuit ratio threshold.

Preferably, in the multi-station short-circuit ratio threshold determination unit 602, the preset transient overvoltage threshold is 1.3 p.u.

Preferably, the first configuration unit 603 is used to configure a preset number of condensers on the low-voltage side of the grid-connected point of the new energy with the smallest short-circuit ratio of the new energy multi-site station, and recalculate the new energy multi-field of each new energy Station short circuit ratio.

Preferably, wherein said system also includes:

The update unit is used to re-determine the new energy with the smallest short-circuit ratio of the new energy multi-station when the new energy multi-station short-circuit ratio of the new energy is less than the threshold value of the new energy multi-station short-circuit ratio, and enter the first hive.

Preferably, the transient overvoltage updating unit 604 is configured to recalculate the short-circuit ratio of each new energy source when the new energy multi-site short-circuit ratio of each new energy source is greater than or equal to the new energy multi-site short-circuit ratio threshold. transient overvoltage.

The optimal scheme of condenser configuration determination unit 605 is used to determine that the current scheme of condenser configuration is the optimum scheme of condenser configuration when the transient overvoltage of each new energy source is less than or equal to the preset transient overvoltage threshold.

Preferably, wherein said system also includes:

The second configuration unit is used to configure a preset number of condensers on the low-voltage side of the grid-connected point of the new energy source with the largest transient overvoltage when the transient overvoltage of the new energy source is greater than the preset transient overvoltage threshold, and Enter the transient overvoltage update unit to recalculate the transient overvoltage of each new energy until the transient overvoltage of each new energy is less than or equal to the preset transient overvoltage threshold, then enter the configuration of the controller Optimal solution determination unit.

The condenser optimal configuration system 400 for suppressing the transient overvoltage of new energy in the embodiment of the present invention corresponds to the optimal configuration method 100 of the condenser for suppressing the transient overvoltage of new energy in another embodiment of the present invention, I won't repeat them here.

The invention has been described with reference to a small number of embodiments. However, it is clear to a person skilled in the art that other embodiments than the invention disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise therein. All references to "a/the/the [means, component, etc.]" are openly construed to mean at least one instance of said means, component, etc., unless expressly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

Those skilled in the art should understand that the embodiments of the present application may be provided as methods, systems, or computer program products. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present application is described with reference to flowcharts and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the present invention can still be Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall fall within the protection scope of the claims of the present invention.

Claims (8)

1. A method for optimizing the configuration of a condenser for suppressing transient overvoltages of new energy sources, characterized in that the method comprises: Step 1, calculating the new energy multi-site short-circuit ratio of each new energy connected to the target AC-DC hybrid grid and the transient overvoltage of each new energy when the target AC-DC hybrid grid fails; Step 2, when the transient overvoltage of new energy is greater than the preset transient overvoltage threshold, determine the new energy multi-site short-circuit ratio threshold according to the multi-site short-circuit ratio and transient overvoltage of each new energy; Step 3. Configure a preset number of condensers on the low-voltage side of the grid-connected point of the new energy with the smallest short-circuit ratio of new energy multi-site stations, and recalculate the short-circuit ratio of new energy multi-site stations for each new energy source; Step 4, when the new energy multi-station short-circuit ratio of each new energy is greater than or equal to the new energy multi-station short-circuit ratio threshold, recalculate the transient overvoltage of each new energy; Step 5, when the transient overvoltage of each new energy source is less than or equal to the preset transient overvoltage threshold, determine that the current configuration scheme of the condenser is the optimal scheme for the configuration of the condenser; Wherein, the determination of the new energy multi-site short-circuit ratio threshold according to the multi-site short-circuit ratio and transient overvoltage of each new energy source includes: Select the short-circuit ratio of multiple stations corresponding to the new energy with the smallest absolute value of the difference between the transient overvoltage and the preset transient overvoltage threshold among the new energy sources whose transient overvoltage is less than the preset transient overvoltage threshold as the new energy Multi-site station short circuit ratio threshold. 2. The method according to claim 1, characterized in that the method further comprises: When the new energy multi-station short-circuit ratio of the new energy is less than the new energy multi-station short-circuit ratio threshold, re-determine the new energy with the smallest new energy multi-station short-circuit ratio, and return to step 3. 3. The method according to claim 1, wherein the method further comprises: When the transient overvoltage of new energy is greater than the preset transient overvoltage threshold, configure a preset number of condensers on the low-voltage side of the grid-connected point of the new energy with the largest transient overvoltage, and return to step 4 to recalculate each The transient overvoltage of new energy sources, until the transient overvoltage of each new energy source is less than or equal to the preset transient overvoltage threshold, enter step 5. 4. The method according to claim 1, wherein the preset transient overvoltage threshold is 1.3p.u. 5. An optimal configuration system for a condenser that suppresses transient overvoltages of new energy sources, characterized in that the system includes: A calculation unit, used to calculate the new energy multi-site short-circuit ratio of each new energy connected to the target AC-DC hybrid grid and the transient overvoltage of each new energy when the target AC-DC hybrid grid fails; The multi-station short-circuit ratio threshold determination unit is used to determine the new energy source according to the multi-station short-circuit ratio and transient overvoltage of each new energy source when the transient overvoltage of the new energy source is greater than the preset transient overvoltage threshold value. Multi-station short-circuit ratio threshold; The first configuration unit is used to configure a preset number of condensers on the low-voltage side of the new energy grid-connected point with the smallest new energy multi-site short-circuit ratio, and recalculate the new energy multi-site short-circuit ratio of each new energy; The transient overvoltage updating unit is used to recalculate the transient overvoltage of each new energy when the new energy multi-station short-circuit ratio of each new energy is greater than or equal to the new energy multi-station short-circuit ratio threshold; A unit for determining the optimal scheme of condenser configuration, used to determine that the current scheme of condenser configuration is the optimum scheme of condenser configuration when the transient overvoltage of each new energy source is less than or equal to the preset transient overvoltage threshold; Wherein, the multi-station short-circuit ratio threshold determination unit determines the new energy multi-station short-circuit ratio threshold according to the multi-station short-circuit ratio and transient overvoltage of each new energy, including: Select the short-circuit ratio of multiple stations corresponding to the new energy with the smallest absolute value of the difference between the transient overvoltage and the preset transient overvoltage threshold among the new energy sources whose transient overvoltage is less than the preset transient overvoltage threshold as the new energy Multi-site station short circuit ratio threshold. 6. The system according to claim 5, further comprising: The update unit is used to re-determine the new energy with the smallest short-circuit ratio of the new energy multi-station when the new energy multi-station short-circuit ratio of the new energy is less than the threshold value of the new energy multi-station short-circuit ratio, and enter the first hive. 7. The system according to claim 5, wherein the system further comprises: The second configuration unit is used to configure a preset number of condensers on the low-voltage side of the grid-connected point of the new energy source with the largest transient overvoltage when the transient overvoltage of the new energy source is greater than the preset transient overvoltage threshold, and Enter the transient overvoltage update unit to recalculate the transient overvoltage of each new energy until the transient overvoltage of each new energy is less than or equal to the preset transient overvoltage threshold, then enter the configuration of the controller Optimal solution determination unit. 8 . The system according to claim 5 , wherein, in the multi-station short-circuit ratio threshold determination unit, the preset transient overvoltage threshold is 1.3p.u.