CN114421500A - Active splitting section determination method for multi-direct-current feed-in receiving-end power grid - Google Patents

Active splitting section determination method for multi-direct-current feed-in receiving-end power grid Download PDF

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CN114421500A
CN114421500A CN202210129759.4A CN202210129759A CN114421500A CN 114421500 A CN114421500 A CN 114421500A CN 202210129759 A CN202210129759 A CN 202210129759A CN 114421500 A CN114421500 A CN 114421500A
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李少岩
曹珂
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North China Electric Power University
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Abstract

The application provides a method for determining an active splitting section of a multi-direct-current feed-in receiving-end power grid, relates to the technical field of power grids, and solves the technical problem that the result optimality of an existing active splitting section searching method cannot be guaranteed. The method comprises the following steps: obtaining active power required by a load at a load node in the receiving-end power grid; determining an objective function of an active splitting process based on the active power, wherein the objective function is used for representing maximization of load power supply which can be maintained after the active splitting is carried out due to faults of the power grid; determining a constraint condition of a multi-feed short-circuit ratio of the receiving-end power grid, wherein the constraint condition is used for representing the supporting capacity of a grid frame of the receiving-end power grid on a direct-current system commutation voltage; and carrying out linearization processing based on the objective function and the constraint condition to obtain an active splitting section determination result of the receiving-end power grid.

Description

Active splitting section determination method for multi-direct-current feed-in receiving-end power grid
Technical Field
The application relates to the technical field of power grids, in particular to an active splitting section determining method for a multi-direct-current feed-in receiving-end power grid.
Background
At present, as an important measure of the third safety defense line of the power system, active splitting is an effective means for preventing further expansion of accidents by splitting a power grid into two or more subsystems operating in isolation under the condition that the structural integrity of the power grid is not guaranteed after the power grid is greatly disturbed, and the selection of the optimal splitting section is the core and the key of the optimal splitting section.
The single fault can be effectively blocked from being converted into the cascading fault by carrying out active splitting operation on the correct and reasonable section, so that the risk of long-time large-area power failure and even system breakdown is greatly reduced. For a multi-feed system, the sub-systems after the splitting inevitably contain direct current, and in extreme cases, even the situation that multiple direct currents simultaneously fall in the same area exists, and at this time, the voltage supporting capability of the alternating current network frame for the direct current operation is seriously insufficient, which easily causes multiple direct currents to fail in phase change or lock, thereby causing large-area load power loss. At present, most of the existing active splitting cross section searching methods are researched by taking a pure communication system as an object, and are mostly solved based on an intelligent algorithm, and the methods are usually difficult to obtain an optimal solution, so that the optimality of the calculation result of the existing active splitting cross section searching methods is insufficient.
Disclosure of Invention
The invention aims to provide an active splitting section determining method for a multi-direct-current feed-in receiving-end power grid, so as to solve the technical problem that the result optimality of the existing active splitting section searching method is insufficient.
In a first aspect, an embodiment of the present application provides a method for determining an active splitting section of a multi-dc-fed receiving-end power grid, where the method includes:
obtaining active power required by a load at a load node in the receiving-end power grid;
determining an objective function of an active splitting process based on the active power, wherein the objective function is used for representing maximization of load power supply which can be maintained after the active splitting is carried out due to faults of the power grid;
determining a constraint condition of a multi-feed short-circuit ratio of the receiving-end power grid, wherein the constraint condition is used for representing the supporting capacity of a grid frame of the receiving-end power grid on a direct-current system commutation voltage;
and carrying out linearization processing based on the objective function and the constraint condition to obtain an active splitting section determination result of the receiving-end power grid.
In one possible implementation, the set of nodes in the receiving grid includes: the load node, the target node of the direct current feed-in power and other nodes; further comprising:
and determining a power flow constraint condition of the receiving end power grid through a power balance equation, a power output constraint of a generator, a direct current power flow equation, a phase angle difference constraint and a limit constraint on a line power flow on the basis of the line data of the receiving end power grid, the direct current feed-in power at the target node and the generator data of the receiving end power grid. In one possible implementation, the method further includes:
and determining a connectivity constraint condition of the receiving end power grid through a flow balance equation of a connectivity node and a limitation constraint on flow on branch lines based on the flow value of the line of the receiving end power grid in the partition and the electrified state of the node in the node set in the partition.
In one possible implementation, the method further includes:
and determining the coherent/separation constraint condition of the receiving end power grid based on the generator clustering data of the receiving end power grid and the limiting conditions that at least one access is kept between the coherent units and the non-coherent units are not connected in the active splitting process.
In one possible implementation, the step of determining the constraint condition of the multi-feed short-circuit ratio of the receiving grid includes:
carrying out linearization processing on the mapping relation between the multi-feed-in short circuit ratio and the decision variable by establishing a pure reactance equivalent network containing a plurality of current sources according to the physical significance of the node impedance element to obtain a linearization processing result; the current source is a current source arranged at a target node in the receiving-end power grid;
and determining a constraint condition of the multi-feed short-circuit ratio of the receiving-end power grid based on the linearization processing result.
In a possible implementation, the step of performing linearization processing based on the objective function and the constraint condition to obtain an active splitting section determination result of the receiving-end power grid includes:
and carrying out linearization processing on the objective function, the power flow constraint condition, the connectivity constraint condition, the coherence/separation constraint condition and the constraint condition of the multi-feed short-circuit ratio to obtain an active splitting section determination result of the receiving-end power grid.
In a possible implementation, the step of performing linearization on the objective function, the power flow constraint condition, the connectivity constraint condition, the coherence/separation constraint condition, and the constraint condition of the multi-feed short-circuit ratio to obtain the active splitting section determination result of the receiving-end power grid includes:
and taking the branch state of the receiving-end power grid as a decision variable, and carrying out linear processing on the target function, the power flow constraint condition, the connectivity constraint condition, the coherence/separation constraint condition and the constraint condition of the multi-feed-in short-circuit ratio to obtain an active splitting section determination result of the receiving-end power grid.
In a second aspect, an active splitting profile determination apparatus for a multi-dc feed receiving grid is provided, the apparatus comprising:
the obtaining module is used for obtaining active power required by a load at a load node in the receiving-end power grid;
the active power control device comprises a first determination module, a second determination module and a control module, wherein the first determination module is used for determining an objective function of an active splitting process based on the active power, and the objective function is used for representing maximization of load power supply which can be maintained after active splitting is carried out due to faults of a power grid;
the second determination module is used for determining a constraint condition of the multi-feed short-circuit ratio of the receiving-end power grid, wherein the constraint condition is used for representing the supporting capacity of a grid frame of the receiving-end power grid on the commutation voltage of the direct-current system;
and the processing module is used for carrying out linearization processing based on the objective function and the constraint condition to obtain an active splitting section determination result of the receiving-end power grid.
In a third aspect, an embodiment of the present application further provides an electronic device, which includes a memory and a processor, where the memory stores a computer program that is executable on the processor, and the processor implements the method of the first aspect when executing the computer program.
In a fourth aspect, this embodiment of the present application further provides a computer-readable storage medium storing computer-executable instructions, which, when invoked and executed by a processor, cause the processor to perform the method of the first aspect.
The embodiment of the application brings the following beneficial effects:
according to the active splitting section determining method for the multi-direct-current feed-in receiving-end power grid, an objective function of an active splitting process can be determined based on active power, wherein the objective function is used for representing maximization of load power supply which can be maintained after active splitting is carried out on the power grid due to faults; determining a constraint condition of a multi-feed-in short-circuit ratio of a receiving-end power grid, wherein the constraint condition is used for representing the supporting capacity of a grid frame of the receiving-end power grid on the commutation voltage of a direct-current system; and carrying out linearization processing based on the target function and the constraint condition to obtain an active splitting section determination result of the receiving-end power grid. In the scheme, the multi-feed-in short-circuit ratio constraint is introduced in the optimization process of the active splitting section, so that the stable operation capacity of each subsystem after splitting can be effectively improved, and the risk of direct current faults is reduced, and the subsequent system recovery is facilitated.
In order to make the aforementioned objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the detailed description of the present application or the technical solutions in the prior art, the drawings needed to be used in the detailed description of the present application or the prior art description will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a schematic flowchart of an active splitting section determining method for a multi-dc-fed receiving-end power grid according to an embodiment of the present disclosure;
fig. 2 is another schematic flow chart of an active splitting section determining method for a multi-dc-fed receiving-end power grid according to an embodiment of the present disclosure;
fig. 3 is a schematic structural diagram of an active splitting section determining apparatus for a multi-dc-fed receiving-end power grid according to an embodiment of the present disclosure;
fig. 4 shows a schematic structural diagram of an electronic device provided in an embodiment of the present application.
Detailed Description
To make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The terms "comprising" and "having," and any variations thereof, as referred to in the embodiments of the present application, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements but may alternatively include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
At present, with the development of a high-voltage direct-current transmission technology, a plurality of large-scale multi-feed-in direct-current transmission systems are formed in succession, and a current power grid presents a brand new structure form of cross-regional alternating-current and direct-current interconnection. Because the traditional high-voltage direct-current transmission can only normally work depending on the commutation voltage provided by a power grid, if the relative strength of a receiving end grid frame is insufficient, the voltage drop caused by local faults easily causes the serious consequences of direct-current commutation failure and even locking. For systems with multiple dc feeds, the receiving grid must have a grid structure that is strong enough to support the voltage, so as to reduce the potential safety risk suffered by dc operation. Meanwhile, the participation of direct current also puts higher requirements on the security defense and the stable control of the receiving-end power grid.
As an important measure of the third safety line of the power system, active splitting is an effective means for preventing further expansion of accidents by splitting the power grid into two or more subsystems operating in isolation under the condition that the structural integrity of the power grid is not guaranteed after the power grid is subjected to large interference, and the selection of the optimal splitting section is the core and the key of the optimal splitting section. The single fault can be effectively blocked from being converted into the cascading fault by carrying out active splitting operation on the correct and reasonable section, so that the risk of long-time large-area power failure and even system breakdown is greatly reduced. For a multi-feed system, the sub-systems after the splitting inevitably contain direct current, and in extreme cases, even the situation that multiple direct currents simultaneously fall in the same area exists, and at this time, the voltage supporting capability of the alternating current network frame for the direct current operation is seriously insufficient, which easily causes multiple direct currents to fail in phase change or lock, thereby causing large-area load power loss.
The traditional active splitting section searching method is mainly researched by taking a pure alternating current system as an object, and cannot effectively account for adverse effects brought by direct current introduction to power system stability control in a decision process, so that the traditional active splitting section searching method is difficult to be directly applied to a receiving-end power grid engineering scene containing multi-loop direct current feed-in. In addition, most of the existing models are solved by adopting an intelligent algorithm, and although a feasible solution can be found, the optimality and the interpretability of the result are poor.
Based on this, the embodiment of the application provides an active splitting section determining method for a multi-direct-current feed-in receiving-end power grid, and the method can solve the technical problems that the result optimality of the existing active splitting section searching method is insufficient and an optimal solution is difficult to obtain.
Embodiments of the present invention are further described below with reference to the accompanying drawings.
Fig. 1 is a schematic flowchart of an active splitting section determining method for a multi-dc-fed receiving-end power grid according to an embodiment of the present disclosure. Wherein the method is applied to computer equipment. As shown in fig. 1, the method includes:
step S110, obtaining active power required by a load at a load node in a receiving end power grid.
In this embodiment of the present application, the node set in the receiving-end power grid may include: load nodes, target nodes for dc feed power (i.e., nodes that set current sources), and other nodes.
And step S120, determining a target function of the active splitting process based on the active power.
The objective function is used for representing the maximization of the load power supply which can be maintained after the power grid is actively disconnected due to faults.
For the determination of the objective function, for example:
Figure BDA0003502145520000071
in formula (1): pdiIs the active power required by the load at node i; n is the set of all nodes. The formula (1) is an objective function of the active splitting problem, and represents that the maximum load power supply can be maintained after the fault.
And step S130, determining a constraint condition of the multi-feed short-circuit ratio of the receiving-end power grid.
The constraint condition is used for representing the supporting capacity of the grid frame of the receiving-end power grid to the commutation voltage of the direct-current system.
And step S140, performing linearization processing based on the target function and the constraint condition to obtain an active splitting section determination result of the receiving-end power grid.
It should be noted that the multi-feed short-circuit ratio can be used as an important representation of the voltage supporting capability of the ac grid to the dc system, and the index is closely related to the commutation failure. The larger the multi-feed short circuit ratio is, the stronger the voltage supporting capability of the alternating current system is, and the smaller the probability of phase commutation failure during the direct current operation is. By introducing the multi-feed-in short-circuit ratio constraint in the optimization process of the active splitting section, the stable operation capability of each subsystem after splitting can be effectively improved, the risk of direct current fault is reduced, and subsequent system recovery is facilitated.
Aiming at the defects of the existing research, the method provided by the embodiment of the application firstly introduces a multi-feed-in short-circuit ratio constraint closely related to the safe operation of a direct-current system into a conventional active splitting model, then establishes a corresponding objective function and constraint conditions into a mixed integer linear programming form by taking branch circuit states as decision variables, and finally provides a receiving-end power grid active splitting section searching method based on the mixed integer linear programming. The method not only can effectively take the influence of safety factors of multi-direct-current operation into account, but also can make up the defects of an intelligent algorithm in aspects of optimality, stability and the like, so that an active splitting optimization mechanism facing an alternating current-direct current system is perfected.
The active splitting section determining method of the multi-direct-current feed-in receiving-end power grid is a receiving-end power grid active splitting section searching method based on mixed integer linear programming, after multi-feed-in short-circuit ratio constraint is introduced into an established active splitting model, corresponding objective functions and constraint conditions are subjected to linearization processing, a typical mixed integer linear programming problem can be formed, and an effective active splitting section searching method is provided for considering the multi-loop direct-current feed-in receiving-end power grid. In the embodiment of the application, in order to avoid system breakdown under extreme conditions, active disconnection is taken as an important measure of a third safety defense line of the power system, and the load partition is ensured to supply power uninterruptedly to the maximum extent by separating a local power grid from a main grid. Considering the situation that direct current may exist in some islands after the AC/DC receiving end power grid is disconnected, multi-feed short-circuit ratio constraint should be considered when active disconnection section searching is performed to ensure stable operation of each direct current in the subsystem. The invention overcomes the defects of the intelligent algorithm in the aspects of solution optimality, stability and the like by establishing the corresponding objective function and the constraint condition into a mixed integer linear programming form.
In the embodiment of the application, multi-feed-in short-circuit ratio constraint is introduced into a conventional active splitting model, and a receiving-end power grid active splitting optimization model considering multi-direct-current safe and stable operation is established. And moreover, taking the branch state as a decision variable, carrying out linearization processing on a corresponding target function and constraint conditions, and providing a receiving-end power grid active splitting section searching method based on mixed integer linear programming.
The above steps are described in detail below.
In some embodiments, the set of nodes of the receiving end grid includes: load nodes, target nodes of direct current feed power and other nodes; the method may further comprise the steps of:
step a), based on line data of a receiving-end power grid, direct current feed-in power at a target node and generator data of the receiving-end power grid, determining a power flow constraint condition of the receiving-end power grid through a power balance equation, a generator output constraint, a direct current power flow equation, a phase angle difference constraint and a line power flow limitation constraint.
For the power flow constraint, the process is as follows:
Figure BDA0003502145520000091
Figure BDA0003502145520000092
Figure BDA0003502145520000093
Figure BDA0003502145520000094
Figure BDA0003502145520000095
Figure BDA0003502145520000096
in the above formula: gd is the partition number of the system after the disconnection; zijc，gdThe commissioning status of the line in the zone gd; pHVDC，iIs the dc feed power at node i; pgIs the active power output of the generator g; pijcIs the line active power flow;
Figure BDA0003502145520000097
the minimum and maximum output limits of the generator g are respectively set; x is the number ofijcIs a line reactance; m is a very large positive number used to relax the associated inequality constraints; thetaijIs the phase angle difference between two nodes;
Figure BDA0003502145520000101
is the maximum value of the allowable power flow of the line; set GiThe system comprises all generators connected with a node i; k is the set of all lines.
Formula (2) is a power balance equation; the formula (3) is the output constraint of the generator; the formulas (4) and (5) are direct current power flow equations; the formula (6) ensures that the line power flow does not exceed the limit; equation (7) is the phase angle difference constraint.
In some embodiments, the method may further comprise the steps of:
and b), determining a connectivity constraint condition of the receiving end power grid through a flow balance equation of a connectivity node and a limitation constraint on flow on the branch line based on the flow value of the line of the receiving end power grid in the partition and the electrified state of the node in the node set in the partition.
For connectivity constraints, it is noted that the system is implementedAfter the active splitting operation, it is necessary to ensure that the interiors of the generated subsystems are mutually communicated. Firstly, selecting nodes needing to ensure connectivity, and forming a set N togethers: one of the nodes is selected as a source point, and the other nodes are sinks to form a set Ns-1. And (4) regarding each subsystem after the splitting as a single-source multi-sink network, and ensuring the connectivity of each area by using a flow balance principle.
Figure BDA0003502145520000102
Figure BDA0003502145520000103
Figure BDA0003502145520000104
In the above formula: y isijc，gdThe flow value of the line in the zone gd; zz (z)i，gdThe variable is 0-1, representing the charged state of node i in partition gd.
The formula (8) is a flow balance equation of the source point, and ensures that the flow sent by the source point in each subsystem is just the sum of the flows required by each sink point; the formula (9) ensures the flow balance of each sink; equation (10) limits the amount of flow on the branch.
In some embodiments, the method may further comprise the steps of:
and c), determining the coherent/separation constraint condition of the receiving end power grid based on the generator clustering data of the receiving end power grid and the constraint condition that at least one access is kept between the coherent units and the non-coherent units are not connected in the active splitting process.
For the coherent/disjunction constraint, it should be noted that in the active splitting model, it needs to be ensured that at least one path exists between coherent units, and non-coherent units are not connected completely.
Figure BDA0003502145520000111
Figure BDA0003502145520000112
Zijc，gd≥(zzi，gd+zzj，gd)-1 (13)
Zijc，gd≤(zzi，gd+zzj，gd)/2 (14)
Equation (11) is used to ensure that each node belongs to only one partition and that no orphaned nodes exist. When the units are determined to be grouped, the coherent units are electrified in the same area, and the non-coherent units are electrified in different areas. The expression (12) indicates that each line is either put into operation in a certain subarea or is disconnected, and the disconnected group of lines are cut sets and jointly form an optimal splitting section. The expression (13) and (14) shows that the line is put into operation in the subarea only when nodes at two ends of the line are electrified in the same area, and otherwise, the line is not put into operation.
In some embodiments, the step S130 may include the following steps:
carrying out linearization processing on the mapping relation between the multi-feed-in short circuit ratio and the decision variable by establishing a pure reactance equivalent network containing a plurality of current sources according to the physical significance of the node impedance element to obtain a linearization processing result; the current source is a current source arranged at a target node in a receiving-end power grid;
and determining the constraint condition of the multi-feed short-circuit ratio of the receiving-end power grid based on the linearization processing result.
In order to ensure the voltage supporting capability of each subsystem to the dc system dropping in the area after active splitting, a corresponding multi-feed short-circuit ratio constraint needs to be introduced. Based on the physical meaning of the node impedance elements, the linearization processing of the mapping relation of the multi-feed-in short circuit ratio and the decision variable can be realized by constructing an 'accompanying network' which is similar to the original network topology and applies a current source externally.
Figure BDA0003502145520000121
Figure BDA0003502145520000122
Figure BDA0003502145520000123
Figure BDA0003502145520000124
Figure BDA0003502145520000125
Figure BDA0003502145520000126
Figure BDA0003502145520000127
Figure BDA0003502145520000128
In the above formula: i isijc，gdThe current flowing through the line in the gd partition for "companion network", c represents the loop number; bi，gdIs the magnitude of the current injected into node i; pdiThe transmission power per unit value of the ith return direct current is obtained; u shapei，gd，Uj，gdThe voltage value of the node i, j in the equivalent network presented in the partition gd; kMSCR，thThe value of the set multi-feed-in short-circuit ratio threshold is usually 3; n is a radical ofHVDCIs a set of direct current drop points; k0Is a branch set including a grounding branch.
Formula (15) is KCL law; the formula (16) ensures that the current source is injected only in the partition where the direct current feed point is located in the equivalent network; equation (17) means that the current flow rates of nodes other than the earth node and the direct current drop point are balanced; the formulas (18) and (19) are expressed by a large M method; equation (20) may ensure that the line appears to be currentless in non-commissioning zones; equation (21) ensures that the voltage at the node in the non-commissioning partition is zero; equation (22) is a multi-feed short-circuit ratio constraint expressed directly in terms of voltage.
In some embodiments, as shown in fig. 2, the step S140 may include the following steps:
and d), carrying out linearization treatment on the target function, the power flow constraint condition, the connectivity constraint condition, the coherence/separation constraint condition and the constraint condition of the multi-feed short-circuit ratio to obtain an active splitting section determination result of the receiving-end power grid.
In the embodiment of the application, when active splitting section searching is carried out facing a receiving-end power grid, the safety and stability problems of each split subsystem are fully considered besides the conditions of conventional coherent constraint/separation constraint, power flow constraint, connectivity constraint and the like.
In some embodiments, the step d) may include the steps of:
and e), taking the branch state of the receiving-end power grid as a decision variable, and carrying out linear processing on the target function, the power flow constraint condition, the connectivity constraint condition, the coherence/separation constraint condition and the constraint condition of the multi-feed-in short-circuit ratio to obtain an active splitting section determination result of the receiving-end power grid.
Fig. 3 provides a schematic structural diagram of an active splitting section determination device for a multi-dc-feed receiving-end power grid. As shown in fig. 3, the active splitting profile determining apparatus 300 for a multi-dc feed receiving grid includes:
an obtaining module 301, configured to obtain active power required by a load at a load node in the receiving end power grid;
a first determining module 302, configured to determine an objective function of an active splitting process based on the active power, where the objective function is used to characterize a maximization of a load power supply that can be maintained after the active splitting is implemented due to a fault in a power grid;
a second determining module 303, configured to determine a constraint condition of a multi-feed short-circuit ratio of the receiving-end power grid, where the constraint condition is used to characterize a supporting capability of a grid frame of the receiving-end power grid to a commutation voltage of a dc system;
and the processing module 304 is configured to perform linearization processing based on the objective function and the constraint condition to obtain an active splitting section determination result of the receiving-end power grid.
The active splitting section determining device for the multi-direct-current feed-in receiving-end power grid provided by the embodiment of the application has the same technical characteristics as the active splitting section determining method for the multi-direct-current feed-in receiving-end power grid provided by the embodiment, so that the same technical problems can be solved, and the same technical effect can be achieved.
As shown in fig. 4, an electronic device 400 provided in an embodiment of the present application includes a processor 402 and a memory 401, where a computer program operable on the processor is stored in the memory, and when the processor executes the computer program, the steps of the method provided in the foregoing embodiment are implemented.
Referring to fig. 4, the electronic device further includes: a bus 403 and a communication interface 404, the processor 402, the communication interface 404 and the memory 401 being connected by the bus 403; the processor 402 is used to execute executable modules, such as computer programs, stored in the memory 401.
The Memory 401 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 Memory. The communication connection between the network element of the system and at least one other network element is realized through at least one communication interface 404 (which may be wired or wireless), and the internet, a wide area network, a local network, a metropolitan area network, and the like can be used.
Bus 403 may be an ISA bus, PCI bus, EISA bus, or the like. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one double-headed arrow is shown in FIG. 4, but that does not indicate only one bus or one type of bus.
The memory 401 is used for storing a program, and the processor 402 executes the program after receiving an execution instruction, and the method performed by the apparatus defined by the process disclosed in any of the foregoing embodiments of the present application may be applied to the processor 402, or implemented by the processor 402.
The processor 402 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware or instructions in the form of software in the processor 402. The Processor 402 may be a general-purpose Processor, and includes a Central Processing Unit (CPU), a Network Processor (NP), and the like; the device can 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 Gate or transistor logic devices, discrete hardware components. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in the memory 401, and the processor 402 reads the information in the memory 401 and completes the steps of the method in combination with the hardware.
Corresponding to the active splitting section determination method for the multi-dc-feed receiving-end power grid, an embodiment of the present application further provides a computer-readable storage medium, where a computer-executable instruction is stored in the computer-readable storage medium, and when the computer-executable instruction is called and executed by a processor, the computer-executable instruction causes the processor to execute the steps of the active splitting section determination method for the multi-dc-feed receiving-end power grid.
The active splitting section determining device for the multi-direct-current feed-in receiving-end power grid provided by the embodiment of the application can be specific hardware on equipment or software or firmware installed on the equipment and the like. The device provided by the embodiment of the present application has the same implementation principle and technical effect as the foregoing method embodiments, and for the sake of brief description, reference may be made to the corresponding contents in the foregoing method embodiments where no part of the device embodiments is mentioned. It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the foregoing systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and for example, the division of the units is only one logical division, and there may be other divisions when actually implemented, and for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection of devices or units through some communication interfaces, and may be in an electrical, mechanical or other form.
For another example, the flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments provided in the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.
The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or a part of the technical solution may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the active splitting section determining method for a multi-dc-feed receiving grid according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus once an item is defined in one figure, it need not be further defined and explained in subsequent figures, and moreover, the terms "first", "second", "third", etc. are used merely to distinguish one description from another and are not to be construed as indicating or implying relative importance.
Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present application, and are used for illustrating the technical solutions of the present application, but not limiting the same, and the scope of the present application is not limited thereto, and although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope disclosed in the present application; such modifications, changes or substitutions do not depart from the scope of the embodiments of the present application. Are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. An active splitting section determination method for a multi-direct-current feed-in receiving-end power grid is characterized by comprising the following steps:
obtaining active power required by a load at a load node in the receiving-end power grid;
determining an objective function of an active splitting process based on the active power, wherein the objective function is used for representing maximization of load power supply which can be maintained after the active splitting is carried out due to faults of the power grid;
determining a constraint condition of a multi-feed short-circuit ratio of the receiving-end power grid, wherein the constraint condition is used for representing the supporting capacity of a grid frame of the receiving-end power grid on a direct-current system commutation voltage;
and carrying out linearization processing based on the objective function and the constraint condition to obtain an active splitting section determination result of the receiving-end power grid.
2. The method of claim 1, wherein the set of nodes of the receiving grid comprises: the load node, the target node of the direct current feed-in power and other nodes; further comprising:
and determining a power flow constraint condition of the receiving end power grid through a power balance equation, a power output constraint of a generator, a direct current power flow equation, a phase angle difference constraint and a limit constraint on a line power flow on the basis of the line data of the receiving end power grid, the direct current feed-in power at the target node and the generator data of the receiving end power grid.
3. The method of claim 2, further comprising:
and determining a connectivity constraint condition of the receiving end power grid through a flow balance equation of a connectivity node and a limitation constraint on flow on branch lines based on the flow value of the line of the receiving end power grid in the partition and the electrified state of the node in the node set in the partition.
4. The method of claim 3, further comprising:
and determining the coherent/separation constraint condition of the receiving end power grid based on the generator clustering data of the receiving end power grid and the limiting conditions that at least one access is kept between the coherent units and the non-coherent units are not connected in the active splitting process.
5. The method according to claim 1, wherein the step of determining the constraint condition of the multi-feed short-circuit ratio of the receiving grid comprises:
carrying out linearization processing on the mapping relation between the multi-feed-in short circuit ratio and the decision variable by establishing a pure reactance equivalent network containing a plurality of current sources according to the physical significance of the node impedance element to obtain a linearization processing result; the current source is a current source arranged at a target node in the receiving-end power grid;
and determining a constraint condition of the multi-feed short-circuit ratio of the receiving-end power grid based on the linearization processing result.
6. The method according to claim 4, wherein the step of performing linearization processing based on the objective function and the constraint condition to obtain the active splitting fracture determination result of the receiving-end power grid comprises:
and carrying out linearization processing on the objective function, the power flow constraint condition, the connectivity constraint condition, the coherence/separation constraint condition and the constraint condition of the multi-feed short-circuit ratio to obtain an active splitting section determination result of the receiving-end power grid.
7. The method according to claim 6, wherein the step of linearizing the objective function, the power flow constraint, the connectivity constraint, the coherence/dissociation constraint, and the constraint of the multi-feed short-circuit ratio to obtain the active splitting section determination result of the receiving grid comprises:
and taking the branch state of the receiving-end power grid as a decision variable, and carrying out linear processing on the target function, the power flow constraint condition, the connectivity constraint condition, the coherence/separation constraint condition and the constraint condition of the multi-feed-in short-circuit ratio to obtain an active splitting section determination result of the receiving-end power grid.
8. An active splitting profile determination apparatus for a multiple dc feed receiving grid, the apparatus comprising:
the obtaining module is used for obtaining active power required by a load at a load node in the receiving-end power grid;
the active power control device comprises a first determination module, a second determination module and a control module, wherein the first determination module is used for determining an objective function of an active splitting process based on the active power, and the objective function is used for representing maximization of load power supply which can be maintained after active splitting is carried out due to faults of a power grid;
the second determination module is used for determining a constraint condition of the multi-feed short-circuit ratio of the receiving-end power grid, wherein the constraint condition is used for representing the supporting capacity of a grid frame of the receiving-end power grid on the commutation voltage of the direct-current system;
and the processing module is used for carrying out linearization processing based on the objective function and the constraint condition to obtain an active splitting section determination result of the receiving-end power grid.
9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program operable on the processor, and wherein the processor implements the steps of the method of any of claims 1 to 7 when executing the computer program.
10. A computer readable storage medium having stored thereon computer executable instructions which, when invoked and executed by a processor, cause the processor to execute the method of any of claims 1 to 7.
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2048758A2 (en) * 2007-10-12 2009-04-15 Hitachi, Ltd. Power supply apparatus, power management server, power management system, power supply method
CN109038635A (en) * 2018-08-02 2018-12-18 南瑞集团有限公司 It is a kind of meter and HVDC Modulation ability off-the-line section optimization selection method and system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2048758A2 (en) * 2007-10-12 2009-04-15 Hitachi, Ltd. Power supply apparatus, power management server, power management system, power supply method
CN109038635A (en) * 2018-08-02 2018-12-18 南瑞集团有限公司 It is a kind of meter and HVDC Modulation ability off-the-line section optimization selection method and system

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