Receiving end system minimum startup determination method, system, equipment and medium

Abstract

The invention discloses a method, a system, equipment and a medium for determining the minimum starting-up of a receiving end system, which take the minimum starting-up cost as an objective function and consider the gradeability constraint, the spinning reserve constraint and the key section power constraint of a unit. Meanwhile, the constraint of system inertia, the constraint of the system on the supporting capacity of load nodes and the constraint of the system on the supporting capacity of the system on normal operation of large-scale power electronic equipment are considered, and finally the established model is solved through a genetic algorithm. According to the minimum starting scheme obtained through solving of the method, the sufficient stable operation margin of the system can be kept while large-scale new energy is economically consumed, and the method is easy to implement and better meets the operation requirements of a novel electric power system.

Description

Technical Field

[0001] The present application relates to the technical field of power system planning and operation, and in particular to a method, system, device and medium for determining the minimum startup of a receiving-end system. Background Art

[0002] With the advancement of the construction of new power systems, large-scale power electronic equipment represented by new energy sources accounts for an increasingly high proportion. The access of large-scale new energy sources has greatly squeezed the available space of conventional units, resulting in a reduction in system strength, reducing the grid's ability to support the normal operation of large-scale power electronic equipment such as new energy sources (small disturbance stability of power electronic equipment) and the dynamic voltage support capacity of load nodes (voltage stability), and will also lead to insufficient inertia of the system. These problems will threaten the safe operation of the system.

[0003] At present, the optimization of conventional power supply startup mode is mainly considered from the aspects of economy and new energy power consumption, without taking into account the system's support capacity constraints for large-scale power electronic equipment and loads and the system's inertia constraints. Therefore, it is necessary to study a minimum startup optimization method for the receiving system that comprehensively considers the above constraints. Summary of the invention

[0004] The present application provides a method, system, device and medium for determining the minimum power-on time of a receiving-end system, which are used to maintain sufficient stable operation margin of the system while absorbing large-scale new energy.

[0005] In view of this, the first aspect of the present application provides a method for determining the minimum power-on time of a receiving system, the method comprising:

[0006] Obtaining basic information of the power grid system and information of new energy sources connected to the power grid system;

[0007] Based on the basic information and the new energy information, taking the minimum startup cost as the objective function, considering the inertia constraint of the power grid system, the voltage support capacity constraint of the power grid system for the load nodes, and the support capacity constraint of the power grid system for the normal operation of large-scale power electronic equipment, a minimum startup solution model for the receiving end system fed by large-scale power electronic equipment is established;

[0008] A genetic algorithm is used to solve the minimum startup solution model of the receiving end system to obtain a minimum startup solution.

[0009] Optionally, the process of constructing the voltage support capability constraint includes: using a short-circuit capacity index to consider the voltage support strength constraint of the system on the load node;

[0010] The expression of the voltage support strength constraint is:

[0011] ,i=1,...,N L ;

[0012] Where N L is the number of load nodes considered, For a given boot mode The short-circuit capacity of the next i-th load node, is the minimum short-circuit capacity requirement of the i-th load node set in advance.

[0013] Optionally, the process of constructing the support capacity constraint includes: using an operating generalized short-circuit ratio indicator to consider the system's support intensity constraint for large-scale renewable energy;

[0014] The expression of the support strength constraint includes:

[0015]

[0016] in, ;

[0017] In the formula, is the matrix eigenvalue, The larger the value, the better the given boot mode. The greater the support intensity of the power grid system for new energy, T is the number of time periods considered, SB t is the capacity diagonal matrix composed of the predicted output of each renewable energy feed-in point in the tth period, For SB t The inverse matrix, B m is the power frequency node admittance matrix.

[0018] Optionally, the expression of the support strength constraint also includes:

[0019] ;

[0020] In the formula, It is the minimum generalized short-circuit ratio requirement of the power grid system set in advance.

[0021] Optionally, the expression of the inertia constraint is:

[0022] ;

[0023] In the formula, u i is a variable of 0 or 1. i When u is 0, it means that the system will be shut down in the subsequent time period. i When it is 1, it means that the machine is powered on in the subsequent time period. is the number of power plants; is the rated rotational kinetic energy of the i-th running generator; is the rated installed capacity of the i-th operating generator; The minimum inertia requirement preset for the power grid system.

[0024] Optionally, the objective function is expressed as:

[0025] ;

[0026] In the formula, is the number of power plants; u i is a variable of 0 or 1. i When u is 0, it means that the system will be shut down in the subsequent time period. i When it is 1, it means that the machine is powered on in the subsequent time period; C i is the startup cost of the i-th machine; f2 is the given startup method The minimum operating cost during the considered time period.

[0027] Optionally, the constraints of the minimum startup solution model of the receiving-end system also include: climbing capability constraints of the unit, spinning reserve constraints, and key section power constraints.

[0028] A second aspect of the present application provides a receiving-end system minimum startup determination system, the system comprising:

[0029] An acquisition unit, used to acquire basic information of a power grid system and information of new energy sources connected to the power grid system;

[0030] A construction unit is used to establish a minimum startup solution model for a receiving-end system fed by large-scale power electronic equipment based on the basic information and the new energy information, taking the minimum startup cost as the objective function, considering the inertia constraint of the power grid system, the voltage support capacity constraint of the power grid system for load nodes, and the support capacity constraint of the power grid system for the normal operation of large-scale power electronic equipment;

[0031] The solving unit is used to solve the minimum startup solution model of the receiving end system by using a genetic algorithm to obtain a minimum startup solution.

[0032] A third aspect of the present application provides a minimum power-on determination device for a receiving end system, the device comprising a processor and a memory:

[0033] The memory is used to store program codes and transmit the program codes to the processor;

[0034] The processor is used to execute the steps of the method for determining the minimum startup of the receiving system as described in the first aspect according to the instructions in the program code.

[0035] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store program code, and the program code is used to execute the method for determining the minimum startup of the receiving system described in the first aspect above.

[0036] It can be seen from the above technical solutions that this application has the following advantages:

[0037] The present application provides a method for determining the minimum startup of a receiving-end system fed by large-scale power electronic equipment, taking the minimum startup cost as the objective function, considering the climbing capability constraints, rotating reserve constraints, and key section power constraints of the unit, while considering the constraints of system inertia, the system's support capacity constraints for load nodes, and the system's support capacity constraints for the normal operation of large-scale power electronic equipment, and finally using a genetic algorithm to solve the established model. The minimum startup scheme solved by the method of the present application can consume large-scale new energy more economically while maintaining sufficient stable operation margin of the system, and the method of the present application is simple to implement and better meets the requirements of the operation of new power systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A flowchart of a method for determining the minimum power-on time of a receiving-end system provided in an embodiment of the present application;

[0039] Figure 2 A structural diagram of a minimum power-on determination system for a receiving-end system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0041] See also Figure 1 , a method for determining the minimum power-on time of a receiving system provided in an embodiment of the present application includes:

[0042] Step 101: Obtain basic information of the power grid system and information of new energy sources connected to the power grid system.

[0043] It should be noted that, assuming that there are N new energy sources connected to the system w The rated installed capacity is: Pe1, Pe2, ..., Pe Nw Assume that there are N power plants in total g The rated installed capacity is Sg k, rated rotational kinetic energy is W k , the output upper and lower limits are Pgmin k 、Pgmax k , the up and down climbing ability is Pg_up k 、Pg_down k ,k=1,..,N g Assuming that the structural parameters of the system are known (including grid structure parameters, new energy sources, generators, access points of loads, etc.), the needs of generalized short-circuit ratio calculation and system node short-circuit capacity calculation can be met.

[0044] Step 102: Based on the basic information and new energy information, taking the minimum startup cost as the objective function, considering the inertia constraint of the power grid system, the voltage support capacity constraint of the power grid system for the load nodes, and the support capacity constraint of the power grid system for the normal operation of large-scale power electronic equipment, a minimum startup solution model for the receiving-end system fed by large-scale power electronic equipment is established.

[0045] In one embodiment, the constraints of the minimum startup solution model of the receiving-end system in step 102 also include: the climbing capability constraint of the unit, the spinning reserve constraint, and the key section power constraint.

[0046] It should be noted that the minimum startup solution model of the receiving system fed by large-scale power electronic equipment is as follows:

[0047] Objective function:

[0048] (1)

[0049] In the formula, u i is a variable of 0 or 1. i When u is 0, it means that the system will be shut down in the subsequent time period. i When it is 1, it means that the machine is powered on in the subsequent time period. i is the startup cost of the i-th machine. f2 is the given startup method Under this condition, the minimum operating cost, f2, in the considered time period can be evaluated by the following quadratic programming optimization problem:

[0050] (2)

[0051] ,t=1,...,T (3)

[0052] ,t=1,...,T (4)

[0053] ,i=1,...,N g ,t=1,...,T (5)

[0054] ,i=1,...,N g ,t=2,...,T (6)

[0055] ,j=1,...,L (7)

[0056] In the formula, T is the time period considered, a i , b i 、c i are the output cost coefficient of unit i, P i,t is the power forecast value of the i-th renewable energy station in the t-th period, Pd t is the load in the tth period, r t is the reserve requirement for the tth period, A i_j is the sensitivity coefficient of the output of the i-th machine at the j-th section, Pl j is the power constraint of the jth section, and L is the number of sections under consideration. Under a given startup mode, (2)-(7) are quadratic programming problems, which can be solved by mature methods and will not be described here.

[0057] The following describes the specific models for the constraints on system inertia, the system's support capacity for load nodes, and the system's support capacity for the normal operation of large-scale power electronic equipment.

[0058] The constraints considering the system inertia requirement are as follows:

[0059] (8)

[0060] The short-circuit capacity index is used to consider the voltage support strength constraint of the system on the load node, as shown below:

[0061] ,i=1,...,N L (9)

[0062] Where N L is the number of load nodes considered, For a given boot mode The short-circuit capacity of the next i-th load node can be solved using mature commercial software. is the minimum short-circuit capacity requirement of the i-th load node set in advance.

[0063] The generalized short-circuit ratio index is used to consider the system's support strength constraints for large-scale renewable energy. First, according to the given startup method , AC grid impedance parameters and topological structure to obtain the equivalent admittance matrix, and then according to N wThe number of new energy access points is obtained through the Schur complement operation. w The power frequency node admittance matrix B of the Thevenin equivalent network looking at the grid from a feed point m Considering the period t (t=1, .., T), the capacity diagonal matrix SB composed of the predicted output of each renewable energy feed-in point is t The system's support strength for large-scale renewable energy can be measured by the generalized short-circuit ratio index, as shown below:

[0064] (10-1)

[0065] (10-2)

[0066] In the formula, is the matrix eigenvalue, The larger the value, the better the given boot mode. The system supports new energy sources more strongly. The following constraints are added:

[0067] (11)

[0068] In the formula, It is the minimum generalized short-circuit ratio requirement of the system set in advance.

[0069] According to the above method, the minimum startup solution model (1)-(11) of the receiving system fed by large-scale power electronic equipment is established.

[0070] Step 103: Use a genetic algorithm to solve the minimum startup solution model of the receiving end system to obtain a minimum startup solution.

[0071] It should be noted that the following describes how to use a genetic algorithm to solve the problem.

[0072] By boot mode Solve for the optimization variables, that is, for individual u i =(u 1_i ,...,u N_i ),u j_i Represents the start and stop status of the jth machine. When u j_i When u is 0, it means that the system will be shut down in the subsequent time period. j_i When it is 1, it means that the machine is turned on in the subsequent time period.

[0073] a. Initialization. Read in the parameters of the system to be studied. Assume that the population size is N p , randomly generate N p Individual u i =(u 1_i ,...,u N_i), i=1,...,N p The objective functions (1) and (2) are modified as follows:

[0074] (12)

[0075] (13)

[0076] In the formula, when the individual does not meet the constraints, M takes a large positive real number (such as 1000000), otherwise it is 0. Take a large positive real number (such as 1000000). The genetic algorithm evolves with the objective function (12) as the goal.

[0077] b. First, retain the best individual to enter the evolved population. Use the tournament strategy to select two individuals as parent individuals. The two parent individuals perform crossover (such as single-point crossover) to generate a new individual. The newly generated individual is determined to mutate according to a certain probability. If it mutates, the mutation operation is performed to enter the evolved population (such as generating a random number rand in [0,1]. If rand is less than 0.1, the new individual is randomly selected from 1 to N g One of the bits is mutated, such as selecting the kth bit. If the kth bit is 0, it is converted to 1, otherwise it is converted to 0). If it does not mutate, it directly enters the evolved population. Repeat the above selection-crossover-mutation operation until the size of the generated new individuals is N. p Repeat the above evolution process until the termination condition is met. The optimal solution at this time is the required minimum startup solution.

[0078] In the embodiment of the present application, a method for determining the minimum startup of the receiving end system fed by large-scale power electronic equipment is provided, with the minimum startup cost as the objective function, taking into account the climbing ability constraint of the unit, the rotating reserve constraint, the key section power constraint, and the system inertia constraint, the system support capacity constraint for the load node, and the system support capacity constraint for the normal operation of large-scale power electronic equipment, and finally using a genetic algorithm to solve the established model. The minimum startup scheme solved by the method of the present application can consume large-scale new energy in a relatively economical manner while maintaining sufficient stable operation margin of the system, and the method of the present application is simple to implement and better meets the requirements of the operation of new power systems.

[0079] The above is a method for determining the minimum power-on of a receiving system provided in an embodiment of the present application, and the following is a system for determining the minimum power-on of a receiving system provided in an embodiment of the present application.

[0080] See also Figure 2 , a receiving end system minimum startup determination system provided in an embodiment of the present application includes:

[0081] The acquisition unit 201 is used to acquire basic information of the power grid system and information of new energy sources connected to the power grid system.

[0082] The construction unit 202 is used to establish a minimum startup solution model for the receiving system fed by large-scale power electronic equipment based on the basic information and the new energy information, taking the minimum startup cost as the objective function, considering the inertia constraint of the power grid system, the voltage support capacity constraint of the power grid system for the load nodes, and the support capacity constraint of the power grid system for the normal operation of large-scale power electronic equipment.

[0083] The solving unit 203 is used to solve the minimum startup solution model of the receiving end system by using a genetic algorithm to obtain a minimum startup solution.

[0084] Furthermore, an embodiment of the present application also provides a receiving end system minimum startup determination device, the device comprising a processor and a memory:

[0085] The memory is used to store program codes and transmit the program codes to the processor;

[0086] The processor is used to execute the steps of the receiving system minimum startup determination method as described in the above method embodiment according to the instructions in the program code.

[0087] Furthermore, a computer-readable storage medium is provided in an embodiment of the present application, and the computer-readable storage medium is used to store program code, and the program code is used to execute the method for determining the minimum startup of the receiving system described in the above method embodiment.

[0088] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0089] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0090] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0091] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0092] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0093] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0094] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (full name in English: Read-Only Memory, English abbreviation: ROM), random access memory (full name in English: Random Access Memory, English abbreviation: RAM), disk or optical disk and other media that can store program codes.

[0095] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for determining the minimum power-on time of a receiving system, characterized in that: include: Obtaining basic information of the power grid system and information of new energy sources connected to the power grid system; Based on the basic information and the new energy information, taking the minimum startup cost as the objective function, considering the inertia constraint of the power grid system, the voltage support capacity constraint of the power grid system for the load nodes, and the support capacity constraint of the power grid system for the normal operation of large-scale power electronic equipment, a minimum startup solution model for the receiving end system fed by large-scale power electronic equipment is established; A genetic algorithm is used to solve the minimum startup solution model of the receiving end system to obtain a minimum startup solution.

2. The method for determining the minimum startup time of a receiving system according to claim 1, characterized in that: The construction process of the voltage support capability constraint includes: using the short-circuit capacity index to consider the voltage support strength constraint of the system to the load node; The expression of the voltage support strength constraint is: ,i=1,...,N L ; Where N L is the number of load nodes considered, For a given boot mode The short-circuit capacity of the next i-th load node, is the minimum short-circuit capacity requirement of the i-th load node set in advance.

3. The method for determining the minimum startup time of a receiving system according to claim 1, characterized in that: The construction process of the support capacity constraint includes: using the operating generalized short-circuit ratio index to consider the system's support intensity constraint for large-scale renewable energy; The expression of the support strength constraint includes: in, ; In the formula, is the matrix eigenvalue, The larger the value, the better the given boot mode. The greater the support intensity of the power grid system for new energy, T is the number of time periods considered, SB t is the capacity diagonal matrix composed of the predicted output of each renewable energy feed-in point in the tth period, For SB t The inverse matrix, B m is the power frequency node admittance matrix.

4. The method for determining the minimum startup time of a receiving system according to claim 3, characterized in that: The expression of the support strength constraint also includes: ； In the formula, It is the minimum generalized short-circuit ratio requirement of the power grid system set in advance.

5. The method for determining the minimum startup time of a receiving system according to claim 1, characterized in that: The expression of the inertia constraint is: ； In the formula, u i is a variable of 0 or 1. i When u is 0, it means that the system will be shut down in the subsequent time period. i When it is 1, it means that the machine is powered on in the subsequent time period. is the number of power plants; is the rated rotational kinetic energy of the i-th running generator; is the rated installed capacity of the i-th operating generator; The minimum inertia requirement preset for the power grid system.

6. The method for determining the minimum startup time of a receiving system according to claim 1, characterized in that: The expression of the objective function is: ； In the formula, is the number of power plants; u i is a variable of 0 or 1. i When u is 0, it means that the system will be shut down in the subsequent time period. i When it is 1, it means that the machine is powered on in the subsequent time period; C i is the startup cost of the i-th machine; f2 is the given startup method The minimum operating cost during the considered time period.

7. The method for determining the minimum startup time of a receiving system according to claim 1, characterized in that: The constraints of the minimum startup solution model of the receiving-end system also include: the climbing capability constraint of the unit, the spinning reserve constraint, and the key section power constraint.

8. A receiving end system minimum startup determination system, characterized in that: include: An acquisition unit, used to acquire basic information of a power grid system and information of new energy sources connected to the power grid system; A construction unit is used to establish a minimum startup solution model for a receiving-end system fed by large-scale power electronic equipment based on the basic information and the new energy information, taking the minimum startup cost as the objective function, considering the inertia constraint of the power grid system, the voltage support capacity constraint of the power grid system for load nodes, and the support capacity constraint of the power grid system for the normal operation of large-scale power electronic equipment; The solving unit is used to solve the minimum startup solution model of the receiving end system by using a genetic algorithm to obtain a minimum startup solution.

9. A receiving end system minimum startup determination device, characterized in that: The device comprises a processor and a memory: The memory is used to store program codes and transmit the program codes to the processor; The processor is used to execute the receiving system minimum startup determination method described in any one of claims 1-7 according to the instructions in the program code.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store program code, and the program code is used to execute the method for determining the minimum startup of the receiving system according to any one of claims 1-7.

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