Large-scale power grid multi-objective power flow mode adjustment method and device

Abstract

The present invention proposes a method and device for adjusting the multi-objective power flow mode of a large-scale power grid. The method includes: performing power flow calculation for a large-scale power grid to be adjusted; roughly adjusting the power flow mode of the large-scale power grid according to the order of satisfying multiple objectives, and generating a rough adjustment plan for the multi-objective power flow mode for the large-scale power grid; the multiple objectives include: power flow convergence adjustment objectives, DC line power adjustment objectives, AC section power adjustment objectives and bus voltage adjustment objectives; the order of satisfying multiple objectives includes: satisfying multiple objectives in the order from power flow convergence, DC line power, AC section power to bus voltage; obtaining the multi-objective satisfaction state after the rough adjustment of the power flow mode of the large-scale power grid, selecting the target corresponding to the maximum deviation in the multi-objective satisfaction state, fine-tuning the power flow mode of the large-scale power grid, and generating a fine adjustment plan for the multi-objective power flow mode for the large-scale power grid. It is conducive to accurately and efficiently adjusting the multi-objective power flow mode of the large-scale power grid.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system simulation, and in particular relates to a method and a device for adjusting a multi-objective power flow mode of a large-scale power grid. Background Art

[0002] The adjustment of power grid flow mode is the most basic work of power grid simulation analysis, which can provide strong support for the safe and stable operation of the power grid, optimize resource allocation and improve the resilience of the power grid. With the increasing proportion of renewable energy and power electronic equipment in the power grid, the scale and complexity of the power grid are increasing, the system section constraints are high-dimensional and growing massively, and the operation mode is more complex and changeable.

[0003] The traditional means of adjusting the power flow mode of the power grid mainly rely on the control centers at all levels in the power grid. The operation mode compilers of the control center use simulation analysis software as an auxiliary tool, combined with load forecast results, historical operation mode data, boundary conditions and manual experience, manually modify component parameters, and repeatedly adjust the power flow mode until the operation requirements are met.

[0004] However, the adjustment of the power flow mode of the power grid needs to cover a variety of operating scenarios and simulate various operating conditions. The manual adjustment method not only has a huge workload, but the generated power flow mode is not comprehensive enough. It is difficult to meet multiple operating requirements such as voltage and cross-section at the same time, and it is impossible to find the safety boundaries and discover safety hazards in time.

[0005] Therefore, there is an urgent need to propose a more accurate and efficient technical solution for adjusting the multi-objective power flow mode of large-scale power grids. Summary of the invention

[0006] In view of this, the present invention proposes a method and device for adjusting a multi-objective power flow mode of a large-scale power grid, aiming to solve the problems of single target and low efficiency in the existing large-scale power grid power flow mode adjustment.

[0007] In a first aspect, the present invention provides a method for adjusting a multi-objective power flow mode of a large-scale power grid, comprising:

[0008] Carry out power flow calculation for large-scale power grids to be adjusted;

[0009] According to the order of satisfying multiple objectives, the power flow mode of the large-scale power grid is roughly adjusted to generate a rough adjustment plan for the multi-objective power flow mode of the large-scale power grid; the multiple objectives include: power flow convergence adjustment objectives, DC line power adjustment objectives, AC section power adjustment objectives and bus voltage adjustment objectives; the order of satisfying multiple objectives includes: satisfying multiple objectives in the order of power flow convergence, DC line power, AC section power and bus voltage;

[0010] Obtain the multi-objective satisfaction state after the rough adjustment of the large-scale power grid power flow mode, select the target corresponding to the deviation with the largest value in the multi-objective satisfaction state, fine-tune the large-scale power grid power flow mode, and generate a multi-objective power flow mode fine-tuning plan for the large-scale power grid.

[0011] Furthermore, the method of roughly adjusting the large-scale power grid power flow mode according to the order in which multiple objectives are satisfied includes:

[0012] Perform power flow convergence adjustment to adjust the power flow mode of large-scale power grids and meet the power flow convergence adjustment objectives;

[0013] Perform DC line power regulation to adjust large-scale power grid power flow patterns and meet DC line power regulation targets;

[0014] Perform AC section power adjustment to adjust large-scale power grid power flow mode and meet AC section power adjustment targets;

[0015] Perform bus voltage over-limit adjustment to adjust large-scale power grid flow mode and meet bus voltage adjustment targets.

[0016] Furthermore, the execution of power flow convergence adjustment to adjust the power flow mode of a large-scale power grid and meet the power flow convergence adjustment target includes:

[0017] Checking the data to make each component parameter match the large-scale power grid; or

[0018] According to the unbalanced amount of regional active power, the corresponding component parameters are adjusted to balance the regional active power; or

[0019] For the scenario where the regional reactive power cannot be balanced locally, adjust the corresponding component parameters to balance the regional reactive power locally.

[0020] Furthermore, the DC line power adjustment is performed to adjust the large-scale power grid power flow mode and meet the DC line power adjustment target, including:

[0021] Calculate the power deviation between the current power of the DC line and the target power;

[0022] Determine an adjustable generator set according to the power deviation, and adjust the parameters of the generator set components; or

[0023] Determine the switching amount of the DC filter according to the power deviation, determine the DC filter that can be switched, and switch the DC filter that can be switched; or

[0024] When it is determined that the DC bus voltage exceeds the limit, an adjustable reactive power compensation device near the DC bus is determined, and the parameters of components of the adjustable reactive power compensation device are adjusted.

[0025] Furthermore, the AC section power adjustment is performed to adjust the large-scale power grid power flow mode and meet the AC section power adjustment target, including:

[0026] Calculate the power deviation between the current power and the target power of the AC section;

[0027] According to the power deviation, determining an adjustable generator set and adjusting the parameters of the generator set components;

[0028] When it is determined that the power flow does not converge, an adjustable reactive power compensation device near the reactive power weak point is determined, and the parameters of the adjustable reactive power compensation device components are adjusted.

[0029] Furthermore, the execution of bus voltage over-limit adjustment to adjust the large-scale power grid flow mode and meet the bus voltage adjustment target includes:

[0030] For the out-of-limit bus whose voltage does not fall within the upper and lower voltage limits,

[0031] Determine an adjustable reactive power compensation device near the over-limit bus, and adjust the parameters of components of the adjustable reactive power compensation device; or

[0032] Determine an adjustable transformer near the out-of-limit bus, and adjust parameters of the adjustable transformer components; or

[0033] An adjustable generator near the off-limit bus is determined, and parameters of components of the adjustable generator are adjusted.

[0034] Further, obtaining a multi-objective satisfaction state after a rough adjustment of the large-scale power grid flow mode, selecting a target corresponding to a deviation with the largest value in the multi-objective satisfaction state, and fine-tuning the large-scale power grid flow mode, including:

[0035] The multi-objective satisfaction state includes: a power flow convergence state target deviation, a normalized DC power state target deviation, a normalized AC section power state target deviation, and a normalized bus voltage state target deviation;

[0036] When it is determined that the target corresponding to the deviation with the largest value in the multi-target satisfaction state is the power flow convergence adjustment target, power flow convergence adjustment is performed to adjust the power flow mode of the large-scale power grid and meet the power flow convergence adjustment target;

[0037] When it is determined that the target corresponding to the deviation with the largest value in the multi-target satisfaction state is the DC line power adjustment target, DC line power adjustment is performed to adjust the large-scale power grid power flow mode and meet the DC line power adjustment target;

[0038] When it is determined that the target corresponding to the deviation with the largest value in the multi-target satisfaction state is the AC section power adjustment target, AC section power adjustment is performed to adjust the large-scale power grid flow mode and meet the AC section power adjustment target;

[0039] When it is determined that the target corresponding to the deviation with the largest value in the multi-target satisfaction state is the bus voltage adjustment target, the bus voltage over-limit adjustment is performed to adjust the large-scale power grid flow mode and meet the bus voltage adjustment target.

[0040] Furthermore, the generating of a multi-objective power flow mode rough adjustment scheme for the large-scale power grid includes:

[0041] Record, in order of execution, the actions of adjusting component parameters in the power flow convergence adjustment, the actions of adjusting component parameters in the AC section power adjustment, the actions of adjusting component parameters in the DC line power adjustment, and the actions of adjusting component parameters in the bus voltage over-limit adjustment;

[0042] The generating of a multi-objective power flow mode fine-tuning scheme for the large-scale power grid includes:

[0043] In order of execution, record the actions of adjusting component parameters in the power flow convergence adjustment, the actions of adjusting component parameters in the AC section power adjustment, the actions of adjusting component parameters in the DC line power adjustment, or the actions of adjusting component parameters in the bus voltage over-limit adjustment.

[0044] In a second aspect, the present invention provides a large-scale power grid multi-objective power flow mode adjustment device, which is used to execute the large-scale power grid multi-objective power flow mode adjustment method as described in the first aspect, comprising:

[0045] The power flow calculation module is used to perform power flow calculation for the large-scale power grid to be adjusted;

[0046] A rough adjustment scheme generating module is used to roughly adjust the power flow mode of a large-scale power grid according to a multi-objective satisfaction order, and generate a multi-objective power flow mode rough adjustment scheme for the large-scale power grid; the multi-objectives include: power flow convergence adjustment target, DC line power adjustment target, AC section power adjustment target and bus voltage adjustment target; the multi-objective satisfaction order includes: satisfying the multi-objectives in the order of power flow convergence, DC line power, AC section power to bus voltage;

[0047] A fine-tuning scheme generation module is used to obtain the multi-objective satisfaction state after the rough adjustment of the large-scale power grid power flow mode, select the target corresponding to the deviation with the largest value in the multi-objective satisfaction state, fine-tune the large-scale power grid power flow mode, and generate a multi-objective power flow mode fine-tuning scheme for the large-scale power grid.

[0048] In a third aspect, the present invention provides a terminal, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method described in the first aspect.

[0049] In a fourth aspect, the present invention provides a computer storage medium storing computer controllable instructions, wherein the computer controllable instructions are used to execute the method described in the first aspect.

[0050] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0052] Figure 1 A schematic diagram of a flow chart of a method for adjusting a large-scale power grid multi-objective power flow mode according to an embodiment of the present invention;

[0053] Figure 2 It is a schematic diagram of a flow chart of executing power flow convergence adjustment in a large-scale power grid multi-objective power flow mode adjustment method according to an embodiment of the present invention;

[0054] Figure 3 It is a schematic diagram of a process of performing DC line power adjustment in a large-scale power grid multi-objective power flow adjustment method according to an embodiment of the present invention;

[0055] Figure 4 It is a schematic diagram of a flow chart of performing AC section power adjustment in a large-scale power grid multi-objective power flow adjustment method according to an embodiment of the present invention;

[0056] Figure 5 It is a schematic diagram of a process of performing bus voltage adjustment in a large-scale power grid multi-objective power flow adjustment method according to an embodiment of the present invention;

[0057] Figure 6 A schematic flow chart of a method for adjusting a large-scale power grid multi-objective power flow mode according to another embodiment of the present invention;

[0058] Figure 7 It is a schematic diagram of the composition of a large-scale power grid multi-objective power flow mode adjustment device according to an embodiment of the present invention;

[0059] Figure 8A schematic diagram of the composition of a terminal to which the large-scale power grid multi-objective power flow mode adjustment method according to an embodiment of the present invention is applied;

[0060] Fig. 9 It is a schematic diagram of a program product to which the large-scale power grid multi-objective power flow mode adjustment method according to an embodiment of the present invention is applied. DETAILED DESCRIPTION

[0061] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0062] Traditional power grid power flow adjustment methods mainly target a single goal and are based on sensitivity, optimization algorithms or practical experience. For example, the automatic adjustment method of power flow based on sensitivity uses the DC power flow model to calculate the sensitivity and calculates the adjustment amount through the reverse equal pairing principle. For example, the characteristics and size of the voltage amplitude and phase angle attenuation indicators are used to identify pathological characteristics, and the pathological characteristics are divided into pathological power flow, unsolvable power flow and other situations, and the interior point method is used to solve them.

[0063] At present, there are also some methods that use expert systems and knowledge base technologies to use the expert experience of formal modeling to artificially generate complex large-scale power grid power flow modes. For example, based on the knowledge base logical reasoning method, the operation mode compiler is simulated to arrange the power flow mode, and an intelligent regional power grid operation mode arrangement decision support system is developed. For example, the cluster analysis method is used to extract characteristic variables that characterize the operation status of the power grid, and a refined management method for the power grid operation mode is proposed. For example, the static network equivalence and expert system are used to study the method of reactive voltage adjustment of a large range of power grids. For example, the rule base of the expert system is combined with the power grid power flow analysis. However, there is no public technical solution that comprehensively considers multiple operation objectives such as power flow convergence, power grid section, DC, voltage, etc. to achieve efficient generation of multi-objective power flow modes.

[0064] On the one hand, due to the huge scale of the power grid and the complexity of the problem, traditional methods cannot completely solve the problem of power grid flow mode adjustment. There are only a few attempts to apply artificial methods to the power grid flow mode adjustment, which have achieved certain results and shown very good application prospects. For example, a method for adjusting the DC power and section power of large-scale power grids using a knowledge-driven method. This method realizes the adjustment of the target power of AC sections and DC lines, single sections and multiple sections by converting power grid data, adjustment status, adjustment rules and adjustment means into a knowledge graph. However, only the DC line power and AC section power targets are considered, and other targets, such as power flow convergence and bus voltage, are not considered. Therefore, there is an urgent need for a power flow mode adjustment method that can be applied to large-scale power grids and comprehensively consider multiple adjustment targets.

[0065] On the other hand, with the massive access to new energy and power electronic equipment, the operation mode of the power grid has become more complex and changeable. The power flow mode adjustment needs to cover a variety of operation scenarios, simulate various operating conditions, and meet multiple operation goals such as cross-section power, DC power, and voltage within the limit. Relying on the work experience of the operation mode compiler to use the "trial and error method" to adjust the power flow mode is not only labor-intensive and inefficient, but also difficult to meet multiple goals at the same time.

[0066] The present invention provides a technical solution for adjusting the multi-objective power flow mode of a large-scale power grid. According to different power flow target adjustment scenarios, multiple power flow state adjustment models such as power flow convergence, DC power, section power, bus voltage, etc. are independently established. By controlling the adjustment priority of different state targets and switching the current adjustment target state according to the deviation amount, a unified multi-objective power flow adjustment model is constructed, the next adjustment direction is clarified and the power flow state adjustment model to be used is determined, and finally a power flow mode that meets multiple targets is generated, which is conducive to quickly and efficiently adjusting the multi-objective power flow mode of a large-scale power grid.

[0067] The technical solution for adjusting the multi-objective power flow mode of a large-scale power grid provided by the present invention establishes various power flow state adjustment models such as power flow convergence, DC power, section power, bus voltage, etc. for various scenarios of large-scale power flow mode adjustment; by controlling the adjustment priority of different states and switching the adjustment state according to the deviation amount, a unified model for multi-objective power flow adjustment is constructed, thereby realizing a large-scale power flow mode adjustment method integrating multiple scenarios and multiple objectives.

[0068] like Figure 1 As shown, the large-scale power grid multi-objective power flow mode adjustment method according to the embodiment of the present invention includes the following steps S100, S200 and S300.

[0069] S100: Calculate power flow for large-scale power grids to be adjusted;

[0070] S200: According to the order in which multiple objectives are satisfied, roughly adjusting the power flow mode of a large-scale power grid, and generating a rough adjustment plan for the multi-objective power flow mode of the large-scale power grid; the multiple objectives include: a power flow convergence adjustment target, a DC line power adjustment target, an AC section power adjustment target, and a bus voltage adjustment target; the order in which multiple objectives are satisfied includes: satisfying the multiple objectives in the order from power flow convergence, DC line power, AC section power to bus voltage;

[0071] S300: Obtain a multi-objective satisfaction state after rough adjustment of a large-scale power grid power flow mode, select a target corresponding to a deviation with the largest value in the multi-objective satisfaction state, fine-tune the large-scale power grid power flow mode, and generate a multi-objective power flow mode fine-tuning plan for the large-scale power grid.

[0072] Specifically, in step S100, for the large-scale power grid to be adjusted, a simulation model corresponding to various components, various component parameters, and electrical connection relationships between components in the power grid is established, and the established simulation model is used to perform power flow calculation. Through power flow calculation, if it is determined that the current state is a power flow convergence state, then the next adjustment target is the DC line power adjustment, the power adjustment of each AC section, and the voltage adjustment of each busbar; if the current state is a power flow non-convergence state, then the next adjustment target is the power flow convergence adjustment, and other target adjustments can be performed after the power flow is adjusted to convergence.

[0073] Specifically, in step S200, the multiple objectives include: power flow convergence adjustment objective, DC line power adjustment objective, AC section power adjustment objective and bus voltage adjustment objective; the order of satisfying the multiple objectives includes: satisfying the multiple objectives in the order from power flow convergence, DC line power, AC section power to bus voltage. The above order of satisfying the multiple objectives sets clear priorities for multiple adjustment objectives; that is, the adjustments are made in sequence according to the priorities of power flow convergence adjustment, DC power adjustment, section power adjustment and bus voltage adjustment. In this way, the influence of the subsequent adjustment objectives on the previous adjustment objectives is smaller, such as being conducive to the rapid convergence of large-scale power grids in a limited number of iterations, being conducive to the efficient adjustment of multi-objective power flow modes of large-scale power grids, and having higher overall adjustment efficiency in multiple scenarios.

[0074] Specifically, in step S200, the method of roughly adjusting the large-scale power grid power flow mode according to the order in which multiple objectives are satisfied includes:

[0075] Perform power flow convergence adjustment to adjust the power flow mode of large-scale power grids and meet the power flow convergence adjustment objectives;

[0076] Perform DC line power regulation to adjust large-scale power grid power flow patterns and meet DC line power regulation targets;

[0077] Perform AC section power adjustment to adjust large-scale power grid power flow mode and meet AC section power adjustment targets;

[0078] Perform bus voltage over-limit adjustment to adjust large-scale power grid flow mode and meet bus voltage adjustment targets.

[0079] In this way, according to the order of satisfying multiple objectives, when roughly adjusting the power flow mode of a large-scale power grid, adjustments are made in sequence according to the priorities of power flow convergence adjustment, DC power adjustment, section power adjustment and bus voltage adjustment. The later adjustment objectives have less impact on the earlier adjustment objectives, which is conducive to the rapid convergence of large-scale power grids in a limited number of iterations, and is conducive to the efficient adjustment of multi-objective power flow modes of large-scale power grids, and the overall adjustment efficiency is higher in multiple scenarios.

[0080] In some embodiments, the performing of power flow convergence adjustment to adjust the power flow mode of a large-scale power grid and meet the power flow convergence adjustment target includes:

[0081] Checking the data to make each component parameter match the large-scale power grid; or

[0082] According to the unbalanced amount of regional active power, the corresponding component parameters are adjusted to balance the regional active power; or

[0083] For the scenario where the regional reactive power cannot be balanced locally, adjust the corresponding component parameters to balance the regional reactive power locally.

[0084] As mentioned above, there are three types of adjustment measures that can be taken to deal with the non-convergence of the power flow. Figure 2 As shown in the figure, among the three non-convergence adjustment measures for power flow, data checking has the highest priority, active balance adjustment or active balance adjustment in the region has the second highest priority, and reactive balance adjustment or reactive balance adjustment in the region has the lowest priority.

[0085] Specifically, checking the data so that each component parameter matches the large-scale power grid includes: checking the data, such as checking whether the type of component parameters, the number of component parameters, and the value of each component parameter are correct and whether they match the large-scale power grid. If there is a data error, obtaining the data updated by the user or obtaining the default value for the large-scale power grid to be adjusted.

[0086] All the above data include: types of component parameters, such as generator, reactive power compensation device, transformer, DC filter, DC line; values ​​of component parameters, such as generator active output, generator switching flag, generator node type, reactive power compensation device switching status, transformer ratio, DC filter switching status; control parameters of power flow calculation, such as whether the power flow calculation method is Newton method or optimal multiplier method.

[0087] Naturally, after the erroneous data is updated, the power flow calculation is performed for the large-scale power grid to be adjusted to determine whether the large-scale power grid to be adjusted still has a power flow non-convergence scenario; if the power flow converges after adjustment, the power of each DC line, the power of each AC section and the voltage of each bus are updated. Naturally, after the erroneous data is updated, the power flow calculation method can also be modified (such as changing the Newton method to the optimal multiplier method with better convergence) to perform power flow calculation for the large-scale power grid to be adjusted.

[0088] For the scenario where the power flow still does not converge, the power flow convergence adjustment is performed, including:

[0089] Determine whether the regional active power is balanced;

[0090] For the scenario of regional active power imbalance, the corresponding component parameters are adjusted according to the regional active power imbalance to make the regional active power balanced.

[0091] Specifically, for the scenario of regional active power imbalance, the imbalance amount is determined; the generator output is modified or the generator start-up and stop flag is adjusted according to the imbalance amount. At this time, adjusting the corresponding component parameters includes: modifying the generator output or adjusting the generator start-up and stop flag according to the imbalance amount.

[0092] Naturally, after the component parameters are updated (such as modifying the generator output or adjusting the generator start-up and stop flags), the power flow calculation is performed for the large-scale power grid to be adjusted to determine whether the large-scale power grid to be adjusted still has a power flow non-convergence scenario; if the power flow converges after adjustment, the power of each DC line, the power of each AC section and the voltage of each bus are updated.

[0093] Naturally, for the scenario of regional active power imbalance, active power balance adjustment or adjustment of regional active power balance, which is a power flow non-convergence adjustment measure, can be repeatedly performed.

[0094] For the scenario where the power flow still does not converge, the power flow convergence adjustment includes:

[0095] Determine whether reactive power is balanced locally;

[0096] For the scenario where the regional reactive power cannot be balanced locally, adjust the corresponding component parameters to balance the regional reactive power locally.

[0097] Specifically, for scenarios where regional reactive power cannot be balanced locally, determine the location of reactive power shortage, modify the switching state of the reactive power compensation device at the location of reactive power shortage, switch on and off the parallel capacitor reactor, or modify the generator node type (such as modifying the PQ node to a PV-PQ node with reactive power support capability).

[0098] At this time, adjusting the corresponding component parameters includes: modifying the switching state of the reactive power compensation device or switching the parallel capacitor reactor or modifying the generator node type at the reactive power shortage position.

[0099] Naturally, after the component parameters are updated (modifying the switching status of the reactive compensation device or switching the parallel capacitor reactor or modifying the generator node type at the reactive power shortage position), the power flow calculation is performed for the large-scale power grid to be adjusted to determine whether the large-scale power grid to be adjusted still has a power flow non-convergence scenario; if the power flow converges after adjustment, the power of each DC line, the power of each AC section and the voltage of each bus are updated.

[0100] Naturally, for the scenario where the regional reactive power cannot be balanced locally, the reactive power balance adjustment or the non-convergence adjustment measure of adjusting the regional reactive power locally can be repeatedly executed.

[0101] Naturally, if the power flow convergence adjustment target still cannot be met after executing the power flow convergence adjustment, the multi-objective power flow adjustment for the large-scale power grid will be terminated.

[0102] It should be understood that during the above-mentioned flow convergence adjustment process, through multiple iterations and / or repeated execution of the above three flow non-convergence adjustment measures, the non-convergence flow will gradually be adjusted to converge to meet the flow convergence adjustment target, and a flow non-convergence adjustment plan will be generated.

[0103] Specifically, the power flow convergence adjustment target includes: within a given number of power flow calculation iterations, each bus voltage does not oscillate or diverge, or can be iterated to within an allowable error accuracy.

[0104] Referring to the above description, the non-convergence adjustment measures for power flow scenarios include: modifying the power flow calculation method, modifying the generator start-stop flag, modifying the generator active output, modifying the generator node type, and modifying the reactive compensation device (such as capacitors or reactors, parallel capacitor reactors) start-stop flag.

[0105] The above multiple iterations and / or repeated executions of the power flow non-convergence adjustment measures are recorded in the order of execution and sorted according to the category of component parameters as the generated power flow non-convergence adjustment scheme. Furthermore, by reproducing the large-scale power grid to be adjusted, the power flow convergence adjustment can be performed for the large-scale power grid to be adjusted according to the generated power flow non-convergence adjustment scheme, which can not only verify the rationality of the power flow non-convergence adjustment scheme, but also evaluate the effectiveness of the power flow convergence adjustment performed above.

[0106] Naturally, if the power flow convergence adjustment is performed and the power flow convergence adjustment target is met, the next step is to perform DC line power adjustment in accordance with the order of meeting multiple targets to adjust the large-scale power grid power flow mode and meet the DC line power adjustment target.

[0107] In some embodiments, performing DC line power adjustment to adjust the large-scale power grid power flow mode and meet the DC line power adjustment target includes:

[0108] Calculate the power deviation between the current power of the DC line and the target power;

[0109] Determine an adjustable generator set according to the power deviation, and adjust the parameters of the generator set components; or

[0110] Determine the switching amount of the DC filter according to the power deviation, determine the DC filter that can be switched, and switch the DC filter that can be switched; or

[0111] When it is determined that the DC bus voltage exceeds the limit, an adjustable reactive power compensation device near the DC bus is determined, and the parameters of components of the adjustable reactive power compensation device are adjusted.

[0112] As mentioned above, three DC line power adjustment measures can be taken for DC line power adjustment. Figure 3 As shown in the figure, among the three DC line power adjustment measures, adjusting the generator set component parameters has the highest priority, adjusting the DC filter component parameters has the second highest priority, and adjusting the DC bus voltage component parameters has the lowest priority.

[0113] Specifically, the DC line power adjustment target includes: a difference between the DC line adjusted power and the target power (or a DC power state target deviation) is less than a given DC line power error threshold.

[0114] Specifically, the difference between the current power of the DC line and the target power is calculated according to the following formula to check whether the DC line power adjustment target is met:

[0115]

[0116] in, is the current power of the DC line or the adjusted power of the DC line; is the target power of the DC line; is the DC line power error threshold.

[0117] Naturally, for multiple DC lines, it is necessary to adjust the power deviation of each DC line in sequence from large to small or from small to large according to the size of the deviation until the DC line power adjustment target is met or the adjustment is terminated.

[0118] Specifically, for a scenario where the DC line does not meet the DC line power adjustment target, an adjustable generator set is determined according to the power deviation, and the generator set component parameters are adjusted, including:

[0119] According to the power deviation, the adjustable generator set at the sending and receiving ends of the DC line is determined, the generator start-stop flag is modified, and the active output of the generator is modified.

[0120] At this time, the parameters of the generator set components to be adjusted include: adjustable generator sets or modification of generator start / stop flags; modification of the generator active output.

[0121] Naturally, after the component parameters are updated (such as modifying the generator startup and shutdown flags, modifying the generator active output), the power flow calculation is performed for the large-scale power grid to be adjusted, and the power of each DC line is updated.

[0122] Naturally, for a scenario where the DC line does not meet the DC line power adjustment target, the DC line power adjustment measure of adjusting the generator set component parameters can be repeatedly executed.

[0123] Specifically, for a scenario where a DC line does not meet a DC line power adjustment target, a DC filter switching amount (for example, the number of switchings) is determined based on the power deviation, a switchable DC filter is determined, and the switchable DC filter is switched, including: calculating a total switching capacity of the DC filter based on the power deviation, determining the number of DC filters that need to be switched based on the rated capacity of each group of DC filters, and searching for the DC filter to switch.

[0124] At this time, the adjusted DC filter component parameters include: a switchable DC filter or a modified DC filter switching state.

[0125] Naturally, after the component parameters are updated (such as modifying the switching state of the DC filter), the power flow calculation is performed for the large-scale power grid to be adjusted, and the power of each DC line is updated.

[0126] Naturally, for a scenario where the DC line does not meet the DC line power adjustment target, the DC line power adjustment measure of adjusting the DC filter component parameters can be repeatedly performed.

[0127] Specifically, for the scenario where the DC line does not meet the DC line power adjustment target, when it is determined that the DC bus voltage exceeds the limit, an adjustable reactive compensation device near the DC bus is determined, and the adjustable reactive compensation device component parameters are adjusted, including: searching for reactive compensation equipment near the DC bus, and adjusting the switching state of the reactive compensation device near the DC bus.

[0128] At this time, the adjusted DC bus voltage component parameters include: the switching state of the reactive power compensation device near the DC bus.

[0129] Naturally, after the component parameters are updated (such as modifying the switching status of the reactive compensation device near the DC bus), the power flow calculation is performed for the large-scale power grid to be adjusted, and the power of each DC line is updated.

[0130] Naturally, for a scenario where the DC line does not meet the DC line power adjustment target, the DC line power adjustment measure of adjusting the DC filter component parameters can be repeatedly performed.

[0131] It should be understood that, in the above DC line power adjustment process, the above three DC line power adjustment measures are iterated and / or repeated for multiple times until the DC line power adjustment target is met and a DC line power adjustment plan is generated.

[0132] Referring to the above description, for the scenario where the DC line does not meet the DC line power adjustment target, the DC line power adjustment measures taken include: modifying the generator switching flag, modifying the generator active output, modifying the DC filter switching state, and modifying the reactive compensation device switching state near the AC bus connected to the DC line.

[0133] The DC line power adjustment measures iterated and / or repeatedly executed above are recorded in the order of execution and sorted according to the category of component parameters as the generated DC line power adjustment scheme. Furthermore, by reproducing the large-scale power grid to be adjusted, the DC line power adjustment can be performed according to the generated DC line power adjustment for the large-scale power grid to be adjusted, which can not only verify the rationality of the DC line power adjustment scheme, but also evaluate the effectiveness of the DC line power adjustment performed above.

[0134] Naturally, if the DC line power adjustment is performed to meet the DC line power adjustment target, then the AC section power adjustment is performed in the next step according to the multi-target satisfaction order to adjust the large-scale power grid flow mode and meet the AC section power adjustment target.

[0135] In some embodiments, the performing of AC section power adjustment to adjust the large-scale power grid power flow mode and meet the AC section power adjustment target includes:

[0136] Calculate the power deviation between the current power and the target power of the AC section;

[0137] According to the power deviation, determining an adjustable generator set and adjusting the parameters of the generator set components;

[0138] When it is determined that the power flow does not converge, an adjustable reactive power compensation device near the reactive power weak point is determined, and the parameters of the adjustable reactive power compensation device components are adjusted.

[0139] As mentioned above, two AC section power adjustment measures can be adopted for AC section power adjustment. Figure 4As shown in the figure, among these two AC section power adjustment measures, adjusting the parameters of the generator set components has the highest priority, and adjusting the parameters of the reactive compensation device components has the second highest priority.

[0140] Specifically, the AC section power adjustment target includes: a difference between the AC section adjusted power and the target power is less than a given AC section power error threshold.

[0141] Specifically, the power deviation between the current power of the AC section and the target power is calculated according to the following formula to verify whether the AC section power adjustment target is met:

[0142]

[0143] in, is the target power of the AC section; It is the current power of the AC section or the power after the AC section power is adjusted; is the AC section power error threshold.

[0144] Specifically, for a scenario where the AC section does not meet the AC section power adjustment target, an adjustable generator set is determined according to the power deviation, and the generator set component parameters are adjusted, including:

[0145] According to the power deviation, the adjustable generator set is found, the generator start-stop flag is modified, and the generator active output is modified.

[0146] At this time, the generator set component parameters to be adjusted include: adjustable generator sets or modification of generator start / stop flags; modification of generator active output.

[0147] Naturally, after the component parameters are updated (such as modifying the generator startup and shutdown flags, modifying the generator active output), the power flow calculation is performed for the large-scale power grid to be adjusted to determine whether the AC section power flow converges, and update the power of each AC section.

[0148] Naturally, for the scenario where the AC section does not meet the AC section power adjustment target, the AC section power adjustment measure of adjusting the generator set component parameters can be repeatedly executed.

[0149] Specifically, for the scenario where the AC section power flow does not converge, an adjustable reactive power compensation device near a reactive power weak point is determined, and the parameters of the adjustable reactive power compensation device components are adjusted, including:

[0150] Find the adjustable reactive power compensation equipment near the reactive power weak point and make adjustments, such as adjusting the switching status of the adjustable reactive power compensation device near the reactive power weak point.

[0151] At this time, the adjusted reactive power compensation device component parameters include: the switching state of the reactive power compensation device that can be adjusted near the reactive power weak point.

[0152] Naturally, after the component parameters are updated (such as modifying the switching state of the adjustable reactive compensation device near the reactive weak point), the power flow calculation is performed for the large-scale power grid to be adjusted, and the power of each AC section is updated.

[0153] Naturally, for the scenario where the AC section does not meet the AC section power adjustment target, the AC section power adjustment measure of adjusting the reactive compensation device component parameters can be repeatedly executed.

[0154] It should be understood that in the above AC section power adjustment process, the above two AC section power adjustment measures are executed through multiple iterations and / or repetitions until the AC section power adjustment target is met and an AC section power adjustment plan is generated.

[0155] Referring to the above description, for the scenario where the AC section does not meet the AC section power adjustment target, the AC section power adjustment measures taken include: modifying the generator start-stop flag, modifying the generator active output, and modifying the switching status of the adjustable reactive compensation device near the reactive weak point.

[0156] The AC section power adjustment measures that are iterated and / or repeatedly executed above are recorded in the order of execution and sorted according to the category of component parameters as the generated AC section power adjustment plan. Furthermore, by reproducing the large-scale power grid to be adjusted, the AC section power adjustment can be performed according to the generated AC section power adjustment for the large-scale power grid to be adjusted, which can not only verify the rationality of the AC section power adjustment plan, but also evaluate the effectiveness of the AC section power adjustment performed above.

[0157] Naturally, if the AC section power adjustment is performed to meet the AC section power adjustment target, then in accordance with the multi-target satisfaction order, the next step is to perform bus voltage over-limit adjustment to adjust the large-scale power grid flow mode and meet the bus voltage adjustment target.

[0158] In some embodiments, the performing of bus voltage over-limit adjustment to adjust the large-scale power grid flow mode and meet the bus voltage adjustment target includes:

[0159] For the out-of-limit bus whose voltage does not fall within the upper and lower voltage limits,

[0160] Determine an adjustable reactive power compensation device near the over-limit bus, and adjust the parameters of components of the adjustable reactive power compensation device; or

[0161] Determine an adjustable transformer near the out-of-limit bus, and adjust parameters of the adjustable transformer components; or

[0162] An adjustable generator near the off-limit bus is determined, and parameters of components of the adjustable generator are adjusted.

[0163] As mentioned above, there are three bus voltage over-limit adjustment measures that can be taken. Figure 5 As shown in the figure, among the three bus voltage over-limit adjustment measures, adjusting the parameters of reactive compensation equipment components has the highest priority, adjusting the parameters of adjustable transformer components near the over-limit bus has the second highest priority, and adjusting the parameters of adjustable generator components near the over-limit bus has the lowest priority.

[0164] Specifically, the bus voltage over-limit adjustment target includes: after the bus voltage over-limit adjustment, the bus voltage is less than the voltage upper limit and greater than the voltage lower limit.

[0165] Specifically, whether the bus voltage falls between the voltage upper limit and the voltage upper limit is determined according to the following formula to verify whether the bus voltage over-limit adjustment target is met:

[0166]

[0167] in, To adjust the bus voltage; is the upper limit of bus voltage; The lower limit of bus voltage.

[0168] Naturally, for multiple over-limit buses whose voltages do not fall within the upper and lower voltage limits, they need to be adjusted respectively to meet the bus voltage over-limit adjustment target or terminate the adjustment.

[0169] Specifically, for an out-of-limit bus whose voltage does not fall within the voltage upper and lower limits, determining an adjustable reactive power compensation device near the out-of-limit bus, and adjusting the adjustable reactive power compensation device component parameters include:

[0170] Find an adjustable reactive power compensation device near the off-limit bus, and adjust the parameters of components of the adjustable reactive power compensation device.

[0171] At this time, the adjusted reactive power compensation device component parameters near the over-limit bus include: the switching state of the adjustable reactive power compensation device near the over-limit bus.

[0172] Naturally, after the component parameters are updated (such as modifying the switching status of the adjustable reactive compensation equipment near the over-limit bus), the power flow calculation is performed for the large-scale power grid to be adjusted, and the voltage of each bus is updated.

[0173] Naturally, for the scenario where the bus voltage over-limit adjustment target is not met, the bus voltage over-limit adjustment measure of reactive compensation device component parameters can be repeatedly executed.

[0174] Specifically, for an out-of-limit bus whose voltage does not fall within the voltage upper and lower limits, an adjustable transformer near the out-of-limit bus is determined, and the adjustable transformer component parameters are adjusted, including: searching for an adjustable transformer near the out-of-limit bus and modifying the adjustable transformer ratio.

[0175] At this time, the adjusted transformer component parameters include: an adjustable transformer ratio.

[0176] Naturally, after the component parameters are updated (e.g., the adjustable transformer ratio is modified), the power flow calculation is performed for the large-scale power grid to be adjusted, and the voltage over-limit of each bus is updated.

[0177] Naturally, for the scenario where the bus voltage over-limit adjustment target is not met, the bus voltage over-limit adjustment measure of adjusting the adjustable transformer component parameters near the over-limit bus can be repeatedly executed.

[0178] Specifically, for an out-of-limit bus whose voltage does not fall within the voltage upper and lower limits, determining an adjustable generator near the out-of-limit bus, and adjusting the adjustable generator component parameters include: searching for an adjustable generator near the out-of-limit bus, and modifying the adjustable generator terminal voltage.

[0179] At this time, the adjusted generator component parameters include: the adjustable generator terminal voltage near the over-limit bus.

[0180] Naturally, after the component parameters are updated (e.g., the adjustable generator terminal voltage near the over-limit bus is modified), the power flow calculation is performed for the large-scale power grid to be adjusted, and the over-limit voltage of each bus is updated.

[0181] Naturally, for the scenario where the bus voltage over-limit adjustment target is not met, the bus voltage over-limit adjustment measure of adjusting the adjustable generator component parameters near the over-limit bus can be repeatedly executed.

[0182] It should be understood that, in the above process of executing bus voltage over-limit adjustment, the above three bus voltage over-limit adjustment measures are executed through multiple iterations and / or repetitions until the bus voltage over-limit adjustment target is met and a bus voltage over-limit adjustment plan is generated.

[0183] Referring to the above description, for the scenario where the bus voltage over-limit adjustment target is not met, the bus voltage over-limit adjustment measures taken include: modifying the switching status of the adjustable reactive compensation equipment near the over-limit bus, modifying the adjustable generator terminal voltage near the over-limit bus, and modifying the adjustable transformer ratio near the over-limit bus.

[0184] The bus voltage over-limit adjustment measures that are iterated and / or repeatedly executed above are recorded in the order of execution and sorted according to the category of component parameters as the generated bus voltage over-limit adjustment scheme. Furthermore, by reproducing the large-scale power grid to be adjusted, the bus voltage over-limit adjustment can be performed according to the generated bus voltage over-limit adjustment for the large-scale power grid to be adjusted, which can not only verify the rationality of the bus voltage over-limit adjustment scheme, but also evaluate the effectiveness of the above-mentioned bus voltage over-limit adjustment.

[0185] In the above, the power flow mode of the large-scale power grid is roughly adjusted according to the order of satisfying multiple objectives, and the adjustments are made in sequence according to the priorities of power flow convergence adjustment, DC power adjustment, section power adjustment and bus voltage adjustment. This is conducive to the rapid convergence of the large-scale power grid in a limited number of iterations, and the overall adjustment efficiency of the power flow mode is higher.

[0186] Specifically, the generating of a multi-objective power flow mode rough adjustment scheme for the large-scale power grid includes:

[0187] In order of execution, the actions of adjusting component parameters in the power flow convergence adjustment, the actions of adjusting component parameters in the AC section power adjustment, the actions of adjusting component parameters in the DC line power adjustment, and the actions of adjusting component parameters in the bus voltage over-limit adjustment are recorded. Please refer to the above description and will not repeat them here.

[0188] Although the multi-objective flow mode rough adjustment scheme for the large-scale power grid is generated according to the order of satisfying multiple objectives, the priorities of flow convergence adjustment, DC power adjustment, section power adjustment and bus voltage adjustment are adjusted in sequence, and the flow convergence adjustment objectives, DC line power adjustment objectives, AC section power adjustment objectives and bus voltage over-limit adjustment objectives are met in sequence, but in the subsequent target adjustment process, the satisfaction status of the previously adjusted and satisfied objectives will change with the flow mode adjustment, resulting in the possibility that the previously adjusted objectives may no longer be satisfied.

[0189] To this end, after roughly adjusting the large-scale power grid flow mode, in some embodiments, the step S300, obtaining the multi-objective satisfaction state after the large-scale power grid flow mode is roughly adjusted, selecting the target corresponding to the deviation with the largest value in the multi-objective satisfaction state, and fine-tuning the large-scale power grid flow mode, includes:

[0190] The multi-objective satisfaction state includes: a power flow convergence state target deviation, a normalized DC power state target deviation, a normalized AC section power state target deviation, and a normalized bus voltage state target deviation;

[0191] When it is determined that the target corresponding to the deviation with the largest value in the multi-target satisfaction state is the power flow convergence adjustment target, power flow convergence adjustment is performed to adjust the power flow mode of the large-scale power grid and meet the power flow convergence adjustment target;

[0192] When it is determined that the target corresponding to the deviation with the largest value in the multi-target satisfaction state is the DC line power adjustment target, DC line power adjustment is performed to adjust the large-scale power grid power flow mode and meet the DC line power adjustment target;

[0193] When it is determined that the target corresponding to the deviation with the largest value in the multi-target satisfaction state is the AC section power adjustment target, AC section power adjustment is performed to adjust the large-scale power grid flow mode and meet the AC section power adjustment target;

[0194] When it is determined that the target corresponding to the deviation with the largest value in the multi-target satisfaction state is the bus voltage adjustment target, the bus voltage over-limit adjustment is performed to adjust the large-scale power grid flow mode and meet the bus voltage adjustment target.

[0195] Referring to the above description, when checking whether the DC line power adjustment target, AC section power adjustment target and bus voltage over-limit adjustment target are met, the numerical magnitude, value range and physical dimension of each difference determined are different. In order to compare the size of each difference, each difference is normalized as follows.

[0196] Specifically, the DC power state target deviation Determined according to the following formula:

[0197] ;

[0198] Specifically, the AC section power state target deviation Determined according to the following formula:

[0199] ;

[0200] Specifically, the over-limit value of each over-limit bus is determined using the following formula: :

[0201] ;

[0202] Specifically, the bus voltage state target deviation Determine as follows:

[0203]

[0204] in, For each bus that exceeds the limit, is the minimum over-limit, , is the maximum over-limit, , N is the number of out-of-limit buses, and i is a positive integer not greater than N.

[0205] Specifically, since DC power adjustment, section power adjustment and voltage adjustment are all performed on the basis of power flow convergence, the power flow convergence state target deviation is determined for power flow non-convergence scenarios. is a larger value, such as 100 in the following formula:

[0206] .

[0207] Specifically, when it is determined that the target corresponding to the maximum deviation in the multi-target satisfaction state is the power flow convergence adjustment target, the power flow convergence adjustment is performed to adjust the large-scale power grid power flow mode and meet the power flow convergence adjustment target. Figure 2 The above description will not be repeated here.

[0208] Specifically, when it is determined that the target corresponding to the maximum deviation in the multi-target satisfaction state is the DC line power adjustment target, the DC line power adjustment is performed to adjust the large-scale power grid flow mode and meet the DC line power adjustment target. Figure 3 The above description will not be repeated here.

[0209] Specifically, when it is determined that the target corresponding to the maximum deviation in the multi-target satisfaction state is the AC section power adjustment target, the AC section power adjustment is performed to adjust the large-scale power grid flow mode and meet the AC section power adjustment target. Figure 4 The above description will not be repeated here.

[0210] Specifically, when it is determined that the target corresponding to the maximum deviation in the multi-target satisfaction state is the bus voltage adjustment target, the bus voltage over-limit adjustment is performed to adjust the large-scale power grid flow mode and meet the bus voltage adjustment target. Figure 5 The above description will not be repeated here.

[0211] Specifically, the generating of a multi-objective power flow mode fine-tuning scheme for the large-scale power grid includes:

[0212] In order of execution, the actions of adjusting component parameters in the power flow convergence adjustment, the actions of adjusting component parameters in the AC section power adjustment, the actions of adjusting component parameters in the DC line power adjustment, or the actions of adjusting component parameters in the bus voltage over-limit adjustment are recorded. Please refer to the above description and no further details will be given.

[0213] like Figure 6As shown, a large-scale power grid multi-objective power flow mode adjustment method according to another embodiment of the present application is adjusted in sequence according to the priority of power flow convergence adjustment, DC power adjustment, section power adjustment and bus voltage adjustment. After each state adjustment is completed, it is determined whether all adjustment targets are achieved. If not, the next step of adjustment is performed according to the size of the target deviation, which specifically includes the following steps 1) to 7).

[0214] 1) Set the adjustment times k=1, calculate the power flow, and determine whether it has converged based on the power flow results. If it has converged, make subsequent state adjustments. If it has not converged, make power flow convergence adjustments.

[0215] 2) Perform power flow convergence adjustment according to the power flow convergence adjustment process, and determine whether the power flow has converged after the adjustment is completed. If it has converged, perform DC power adjustment, otherwise, end the adjustment.

[0216] 3) Adjust the DC power according to the DC power adjustment process, and determine whether the DC power meets the target after adjustment. If it does, adjust the cross-section power. If not, continue to adjust the DC power until the target is met or the upper limit of the number of iterations is reached.

[0217] 4) Adjust the section power according to the section power adjustment process, and determine whether the section power meets the target after adjustment. If it does, adjust the bus voltage. If not, continue to adjust the section power until the target is met or the upper limit of the number of iterations is reached.

[0218] 5) Adjust the bus voltage according to the bus voltage adjustment process, and determine whether the bus voltage meets the target after adjustment. If it does, calculate the target deviation of all states. If it does not, continue to adjust the bus voltage until the target is met or the upper limit of the number of iterations is reached.

[0219] 6) Calculate the target deviation of all states and determine whether each target has been achieved. If achieved, the adjustment ends. Otherwise, switch to the state with the largest target deviation for the next adjustment, and the number of adjustments k = k + 1.

[0220] 7) When all goals are achieved, or the frequency is adjusted When the adjustment is completed, the coarse adjustment scheme (the above steps 2) to 5)) and the fine adjustment scheme (the above step 6)) generated in the above steps are output.

[0221] like Figure 7 As shown, the large-scale power grid multi-objective power flow mode adjustment device of the embodiment of the present invention is used to execute the large-scale power grid multi-objective power flow mode adjustment method mentioned above, including:

[0222] A power flow calculation module 10, used for performing power flow calculation for a large-scale power grid to be adjusted;

[0223] The rough adjustment scheme generating module 20 is used to roughly adjust the power flow mode of the large-scale power grid according to the order of satisfying multiple objectives, and generate a rough adjustment scheme of the power flow mode of multiple objectives for the large-scale power grid; the multiple objectives include: power flow convergence adjustment objective, DC line power adjustment objective, AC section power adjustment objective and bus voltage adjustment objective; the order of satisfying multiple objectives includes: satisfying multiple objectives in the order of power flow convergence, DC line power, AC section power and bus voltage;

[0224] The fine-tuning scheme generation module 30 is used to obtain the multi-objective satisfaction state after the rough adjustment of the large-scale power grid power flow mode, select the target corresponding to the deviation with the largest value in the multi-objective satisfaction state, fine-tune the large-scale power grid power flow mode, and generate a multi-objective power flow mode fine-tuning scheme for the large-scale power grid.

[0225] Specifically, when developing a large-scale power grid multi-objective power flow mode adjustment device, it includes establishing four power flow state adjustment models of power flow convergence, DC power, section power, and bus voltage for different power flow target adjustment scenarios; then, by controlling the adjustment order of different states and the switching between states, a unified model of multi-objective power flow adjustment is constructed, thereby realizing the large power grid multi-objective power flow mode adjustment method described above.

[0226] refer to Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 The four flow state adjustment models of flow convergence adjustment, DC adjustment, section adjustment and voltage adjustment are the basis, and the multi-objective flow mode adjustment method of large power grid is the core content.

[0227] Specifically, the power flow convergence state adjustment model is used to automatically adjust the non-convergent power flow to convergence, including: setting a power flow convergence adjustment target and generating a power flow convergence adjustment plan. The power flow convergence adjustment target is used to achieve that within a given number of power flow calculation iterations, each bus voltage does not oscillate and diverge, that is, gradually iterate to within the allowable error accuracy. The power flow convergence adjustment plan is used to generate relevant component parameter adjustment measures for power flows that do not converge due to different reasons by adopting an effective and universal power flow convergence adjustment process.

[0228] like Figure 2As shown, the power flow convergence adjustment process includes three types of adjustment operations: data check, active power balance, and reactive power balance. The power flow convergence adjustment measures may include actions to modify multiple component parameters during the power flow convergence adjustment process, such as modifying the calculation method, modifying the generator start-stop flag, modifying the generator active output, modifying the generator node type, and modifying the reactive compensation device start-stop flag.

[0229] Specifically, the DC power state adjustment model is used to automatically adjust the DC line power to the target power, including setting a DC adjustment target and generating a DC power adjustment plan. The DC power adjustment target is used to constrain or limit the adjusted DC line power and the target power to be less than a given error threshold. The DC power adjustment plan is used to generate relevant component parameter adjustment measures according to the DC power target value adjusted as needed by adopting an effective and universal adjustment process.

[0230] like Figure 3 As shown, the DC power adjustment process includes three types of adjustment operations, namely, calculating the DC power target deviation, adjusting the output of the generator at the sending and receiving ends of the DC line, switching the DC filter according to the adjusted power, and adjusting the DC bus voltage. The DC power adjustment measures may include actions to modify multiple component parameters during the DC power adjustment process, such as modifying the generator switching flag, modifying the generator active output, modifying the DC filter switching flag, and modifying the reactive compensation device switching flag near the AC line connected to the DC bus.

[0231] Specifically, the section power state adjustment model is used to automatically adjust the AC section power to the target power, including setting the section adjustment target and generating the AC power adjustment plan. The section power adjustment target is used to constrain or limit the adjusted section power and the target power to be less than a given error threshold. The section power adjustment plan is used to generate relevant component parameter adjustment measures according to the section power target value that needs to be adjusted by adopting an effective and universal adjustment process.

[0232] like Figure 4 As shown, the section power adjustment process includes calculating the section power target deviation, adjusting the section sending and receiving end generator output, and non-convergence adjustment reactive operation. The section power adjustment measures may include actions to modify multiple component parameters during the section power adjustment process, such as modifying the generator start-stop flag, modifying the generator active output, and modifying the reactive compensation device start-stop flag near the reactive weak point.

[0233] Specifically, the bus voltage state adjustment model is used to adjust the over-limit bus voltage to a reasonable range (between the voltage lower limit and the voltage upper limit), including setting the bus voltage adjustment target and generating the bus voltage adjustment plan. The bus voltage adjustment target is used to constrain or limit the adjusted bus voltage to be less than the voltage upper limit and greater than the voltage upper limit. The bus voltage adjustment plan is used to generate relevant component parameter adjustment measures according to the upper and lower limits of the over-limit bus voltage that need to be adjusted by adopting an effective and universal adjustment process.

[0234] like Figure 5 As shown, the bus voltage adjustment process includes adjusting the reactive power compensation device near the over-limit bus, adjusting the transformer ratio near the over-limit bus, and adjusting the extreme voltage of the generator near the over-limit bus. The bus voltage adjustment measures may include actions to modify multiple component parameters during the bus voltage adjustment process, such as modifying the reactive power compensation device on / off flag, modifying the transformer ratio, and modifying the generator terminal voltage.

[0235] like Figure 6 As shown, the adjustment order of controlling different states means that when there are multiple adjustment targets, the adjustment is carried out in sequence according to the priority of power flow convergence adjustment, DC power adjustment, section power adjustment and bus voltage adjustment. The switching between the states means that after the adjustment of the state is completed, the deviation of each target is calculated, and the state with the largest deviation is switched to perform the next adjustment.

[0236] In order to test the effectiveness and adaptability of the multi-objective power flow adjustment method proposed in this invention in large-scale power grids, the national network data 88369 node system example is used for verification. The state targets are set as follows: the power flow convergence adjustment target is power flow convergence; the DC power adjustment target is shown in Table 1-1; the section power adjustment target is shown in Table 1-2; the bus voltage adjustment target is shown in Table 1-3.

[0237] Table 1-1 DC power adjustment targets

[0238]

[0239] Table 1-2 Section power adjustment targets

[0240]

[0241] Table 1-3 Bus voltage adjustment targets

[0242]

[0243] Specifically, for the national network data 88369 node system example, based on the initial power flow, 1200 groups of test data with different operating modes (such as different generator startup states and outputs, different load levels, and different reactive compensation device configurations) are randomly generated, and a set of non-convergent data is selected from them for multi-objective power flow mode adjustment. The multi-objective power flow mode adjustment for this set of non-convergent data includes the following steps (B1) to (B6):

[0244] (B1) First, perform the power flow calculation. If the power flow calculation does not converge, enter the power flow convergence adjustment process until the power flow converges after adjustment. Some power flow convergence adjustment solutions are shown in Table 2-1.

[0245] Table 2-1 Partial power flow convergence adjustment scheme

[0246]

[0247] (B2) After the power flow converges, the DC power is adjusted. After the adjustment, the DC power reaches the target. The DC power adjustment results are shown in Table 2-2, and some DC power adjustment solutions are shown in Table 2-3.

[0248] Table 2-2 DC power adjustment results

[0249]

[0250] Table 2-3 Some DC power adjustment solutions

[0251]

[0252] (B3) After the DC power reaches the target, the section power adjustment is started; after the adjustment, the section power reaches the target. The section power adjustment results are shown in Table 3-1, and some section power adjustment plans are shown in Table 3-2.

[0253] Table 3-1 Section power adjustment results

[0254]

[0255] Table 3-2 Power adjustment scheme for some sections

[0256]

[0257] (B4) After the section power reaches the target, the bus voltage adjustment begins; after adjustment, all over-limit bus voltages are within the set upper and lower limits (such as 0.937pu~1.0pu). The over-limit bus voltage adjustment results are shown in Table 4-1. Some over-limit bus voltage adjustment plans are shown in Table 4-2.

[0258] Table 4-1 Over-limit bus voltage adjustment results

[0259] The number of over-limit buses before adjustment The number of buses exceeding the limit after adjustment Deviation 6 0 0

[0260] Table 4-2 Partially over-limit bus voltage adjustment scheme

[0261]

[0262] (B5) After all states are adjusted, calculate each deviation, and the results are shown in Table 5-1. It can be seen from the results that the cross-section deviation is the largest.

[0263] Table 5-1 Target deviation of each state

[0264] Target deviation of power flow convergence state DC power deviation Section power deviation Bus voltage deviation 0 0 0.023 0

[0265] Therefore, we switched to section power adjustment. After the second adjustment, the section power reached the target. The section power adjustment plan is shown in Table 5-2.

[0266] Table 5-2 Power adjustment scheme for some sections

[0267]

[0268] (B6) Calculate each deviation and verify that all targets have been achieved.

[0269] In this way, a multi-objective power flow mode adjustment is performed for the set of non-convergent data, and the adjustment ends when all objectives are achieved.

[0270] Similarly, the multi-objective power flow method was adjusted for the other non-convergent data in the test set of 1200 data. After adjustment, there were 1021 sets of data that achieved multiple objectives, and the adjustment success rate was 85.11%, which met the needs of engineering and practice.

[0271] In summary, the large-scale power grid multi-objective power flow adjustment method and device of the embodiments of the present invention are applied to a variety of actual power grid examples with tens of thousands of nodes. The success rate of multiple objective adjustments in the actual power grid examples can reach more than 80%, which verifies the correctness and effectiveness of the method.

[0272] In summary, the large power grid multi-objective power flow mode adjustment method and device of the embodiment of the present invention, according to different power flow mode adjustment scenarios, constructs four types of target state adjustment models, namely power flow convergence adjustment, DC adjustment, section adjustment and voltage adjustment; a large-scale power grid multi-objective power flow mode adjustment method is proposed, which clarifies the direction of the next step of fine adjustment by controlling the adjustment priority of different states and switching the adjustment state according to the deviation amount.

[0273] During the practical deployment stage, the large-scale power grid multi-objective power flow mode adjustment method and device of the embodiment of the present invention can generate a power flow adjustment function module, which can be published in mainstream power system simulation software such as PSASP and PSD-BPA and applied to power flow mode calculation; it can be integrated and run on a variety of simulation platforms; it can be promoted to municipal power companies, provincial power companies, universities and power grid planning departments, which is conducive to improving the automation level of power system simulation software and promoting technological progress in the field of power simulation.

[0274] The embodiment of the present invention also provides a terminal to execute the method. Figure 8 It shows a schematic diagram of a terminal provided by some embodiments of the present invention. Figure 8 As shown, the terminal 8 includes: a processor 800, a memory 801, a bus 802 and a communication interface 803, wherein the processor 800, the communication interface 803 and the memory 801 are connected via the bus 802; the memory 801 stores a computer program that can be run on the processor 800, and the processor 800 executes the method provided by any of the aforementioned embodiments of the present invention when running the computer program.

[0275] The memory 801 may include a high-speed random access memory (RAM), and may also include a non-volatile memory (Non-volatile Memory), such as at least one disk storage. The communication connection between the device network element and at least one other network element is realized through at least one communication interface 803 (which may be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. may be used.

[0276] The bus 802 may be an ISA bus, a PCI bus, or an EISA bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. The memory 801 is used to store programs, and the processor 800 executes the programs after receiving the control instructions. The method disclosed in any implementation of the above embodiments of the present invention may be applied to the processor 800, or implemented by the processor 800.

[0277] The processor 800 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the method can be completed by the hardware integrated logic circuit in the processor 800 or the instruction in the form of software. The processor 800 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present invention can be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present invention may be directly embodied as being executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 801, and the processor 800 reads the information in the memory 801 and completes the steps of the method in combination with its hardware.

[0278] like Fig. 9 As shown, an embodiment of the present invention further provides a computer-readable storage medium corresponding to the method provided in the aforementioned embodiment, wherein the computer-readable storage medium is a CD on which a computer program (i.e., program product 900) is stored. When the computer program is executed by a processor, the method provided in any of the aforementioned embodiments will be executed.

[0279] It should be noted that examples of the computer-readable storage medium may also include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other optical or magnetic storage media, which are not listed here one by one.

[0280] The computer-readable storage medium provided by the embodiment of the present invention is based on the same inventive concept as the present method and has the same beneficial effects as the method adopted, run or implemented by the application program stored therein.

[0281] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these adjustments and modifications of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these changes and modifications.

Claims

1. A large-scale power grid multi-objective power flow adjustment method, characterized in that: include: Carry out power flow calculation for large-scale power grids to be adjusted; According to the order in which multiple objectives are satisfied, roughly adjusting the power flow mode of the large-scale power grid, and generating a rough adjustment plan for the multi-objective power flow mode of the large-scale power grid; The multiple objectives include: power flow convergence adjustment objective, DC line power adjustment objective, AC section power adjustment objective and bus voltage adjustment objective; the multiple objectives are met in the order of power flow convergence, DC line power, AC section power and bus voltage; Obtain the multi-objective satisfaction state after the rough adjustment of the large-scale power grid power flow mode, select the target corresponding to the deviation with the largest value in the multi-objective satisfaction state, fine-tune the large-scale power grid power flow mode, and generate a multi-objective power flow mode fine-tuning plan for the large-scale power grid.

2. The large-scale power grid multi-objective power flow mode adjustment method according to claim 1, characterized in that: The method of roughly adjusting the large-scale power grid flow in accordance with the order in which multiple objectives are satisfied includes: Perform power flow convergence adjustment to adjust the power flow mode of large-scale power grids and meet the power flow convergence adjustment objectives; Perform DC line power regulation to adjust large-scale power grid power flow patterns and meet DC line power regulation targets; Perform AC section power adjustment to adjust large-scale power grid power flow mode and meet AC section power adjustment targets; Perform bus voltage over-limit adjustment to adjust large-scale power grid flow mode and meet bus voltage adjustment targets.

3. The large-scale power grid multi-objective power flow mode adjustment method according to claim 2, characterized in that: The execution of power flow convergence adjustment to adjust the power flow mode of a large-scale power grid and meet the power flow convergence adjustment target includes: Checking the data to make each component parameter match the large-scale power grid; or According to the unbalanced amount of regional active power, the corresponding component parameters are adjusted to balance the regional active power; or For the scenario where the regional reactive power cannot be balanced locally, adjust the corresponding component parameters to balance the regional reactive power locally.

4. The large-scale power grid multi-objective power flow mode adjustment method according to claim 3, characterized in that: The DC line power adjustment is performed to adjust the large-scale power grid power flow mode and meet the DC line power adjustment target, including: Calculate the power deviation between the current power of the DC line and the target power; Determine an adjustable generator set according to the power deviation, and adjust the parameters of the generator set components; or Determine the switching amount of the DC filter according to the power deviation, determine the DC filter that can be switched, and switch the DC filter that can be switched; or When it is determined that the DC bus voltage exceeds the limit, an adjustable reactive power compensation device near the DC bus is determined, and the parameters of components of the adjustable reactive power compensation device are adjusted.

5. The large-scale power grid multi-objective power flow mode adjustment method according to claim 4, characterized in that: The AC section power adjustment is performed to adjust the large-scale power grid power flow mode and meet the AC section power adjustment target, including: Calculate the power deviation between the current power and the target power of the AC section; According to the power deviation, determining an adjustable generator set and adjusting the parameters of the generator set components; When it is determined that the power flow does not converge, an adjustable reactive power compensation device near the reactive power weak point is determined, and the parameters of the adjustable reactive power compensation device components are adjusted.

6. The large-scale power grid multi-objective power flow mode adjustment method according to claim 5, characterized in that: The execution of bus voltage over-limit adjustment to adjust the large-scale power grid flow mode and meet the bus voltage adjustment target includes: For the out-of-limit bus whose voltage does not fall within the upper and lower voltage limits, Determine an adjustable reactive power compensation device near the over-limit bus, and adjust the parameters of components of the adjustable reactive power compensation device; or Determine an adjustable transformer near the out-of-limit bus, and adjust parameters of the adjustable transformer components; or An adjustable generator near the off-limit bus is determined, and parameters of components of the adjustable generator are adjusted.

7. The large-scale power grid multi-objective power flow mode adjustment method according to claim 6, characterized in that: Obtaining a multi-objective satisfaction state after a rough adjustment of a large-scale power grid power flow mode, selecting a target corresponding to a deviation with a maximum value in the multi-objective satisfaction state, and fine-tuning the large-scale power grid power flow mode, including: The multi-objective satisfaction state includes: a power flow convergence state target deviation, a normalized DC power state target deviation, a normalized AC section power state target deviation, and a normalized bus voltage state target deviation; When it is determined that the target corresponding to the deviation with the largest value in the multi-target satisfaction state is the power flow convergence adjustment target, power flow convergence adjustment is performed to adjust the power flow mode of the large-scale power grid and meet the power flow convergence adjustment target; When it is determined that the target corresponding to the deviation with the largest value in the multi-target satisfaction state is the DC line power adjustment target, DC line power adjustment is performed to adjust the large-scale power grid power flow mode and meet the DC line power adjustment target; When it is determined that the target corresponding to the deviation with the largest value in the multi-target satisfaction state is the AC section power adjustment target, AC section power adjustment is performed to adjust the large-scale power grid flow mode and meet the AC section power adjustment target; When it is determined that the target corresponding to the deviation with the largest value in the multi-target satisfaction state is the bus voltage adjustment target, the bus voltage over-limit adjustment is performed to adjust the large-scale power grid flow mode and meet the bus voltage adjustment target.

8. The large-scale power grid multi-objective power flow mode adjustment method according to any one of claims 2 to 7, characterized in that: The generating of a multi-objective power flow mode rough adjustment scheme for the large-scale power grid includes: Record, in order of execution, the actions of adjusting component parameters in the power flow convergence adjustment, the actions of adjusting component parameters in the AC section power adjustment, the actions of adjusting component parameters in the DC line power adjustment, and the actions of adjusting component parameters in the bus voltage over-limit adjustment; The generating of a multi-objective power flow mode fine-tuning scheme for the large-scale power grid includes: In order of execution, record the actions of adjusting component parameters in the power flow convergence adjustment, the actions of adjusting component parameters in the AC section power adjustment, the actions of adjusting component parameters in the DC line power adjustment, or the actions of adjusting component parameters in the bus voltage over-limit adjustment.

9. A large-scale power grid multi-objective power flow mode adjustment device, characterized in that: The method for adjusting the multi-objective power flow mode of a large-scale power grid according to claim 1 comprises: The power flow calculation module is used to perform power flow calculation for large-scale power grids to be adjusted; A rough adjustment scheme generating module is used to roughly adjust the power flow mode of a large-scale power grid according to a multi-objective satisfaction order, and generate a multi-objective power flow mode rough adjustment scheme for the large-scale power grid; the multi-objectives include: power flow convergence adjustment target, DC line power adjustment target, AC section power adjustment target and bus voltage adjustment target; the multi-objective satisfaction order includes: satisfying the multi-objectives in the order of power flow convergence, DC line power, AC section power to bus voltage; A fine-tuning scheme generation module is used to obtain the multi-objective satisfaction state after the rough adjustment of the large-scale power grid power flow mode, select the target corresponding to the deviation with the largest value in the multi-objective satisfaction state, fine-tune the large-scale power grid power flow mode, and generate a multi-objective power flow mode fine-tuning scheme for the large-scale power grid.

10. A terminal, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method described in any one of claims 1 to 8.

11. A computer storage medium, characterized in that: Computer controllable instructions are stored, and the computer controllable instructions are used to execute the method according to any one of claims 1 to 8.

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