Method and device for calculating flexibility range of active distribution network considering dynamic capacity increase

Abstract

The present application relates to the technical field of power system dispatching and operation, and in particular to a method and device for calculating the flexibility range of an active distribution network considering dynamic capacity increase, wherein the method includes: obtaining measurement data of distribution line parameters and environmental variables around the line, and establishing a line dynamic capacity estimation model based on the principle of thermal balance, and calculating the actual available capacity of the distribution line in different time periods; based on the operation constraints of the distribution network and distributed resources, establishing an active distribution network model that depicts the output power flexibility range allowed for the safe operation of the active distribution network; applying the actual available capacity of the distribution line in different time periods to the active distribution network model, and obtaining the output power flexibility range of the distribution network based on the dynamic line capacity. In this way, the transmission capacity of the distribution line can be increased, the output power flexibility range of the active distribution network can be expanded, and the operation economy and safety of the power grid can be improved without increasing line investment.

Description

Technical Field

[0001] The present application relates to the technical field of power system dispatching and operation, and in particular to a method and device for calculating the flexibility range of an active distribution network taking dynamic capacity increase into consideration. Background Art

[0002] Under the trend of sustainable development and energy conservation and carbon reduction, the penetration rate of distributed resources is gradually increasing. Some small-scale distributed energy resources (DER) enter the low-voltage distribution network to replace large-scale centralized power plants, which causes insufficient reliable capacity supply. Therefore, close cooperation between transmission and distribution systems is necessary to improve the safety and reliability of power grid operation. Under the role of active distribution network, distributed resources connected to the distribution network can not only provide local power demand, but also provide flexible supply to the power operation system.

[0003] Application Contents

[0004] The present application provides a method and device for calculating the flexibility range of an active distribution network taking into account dynamic capacity expansion, which can increase the transmission capacity of distribution lines, expand the output power flexibility range of the active distribution network, and improve the operating economy and safety of the power grid without increasing line investment.

[0005] The first aspect of the present application provides a method for calculating the flexibility range of an active distribution network considering dynamic capacity increase, comprising the following steps:

[0006] Obtain the measured data of distribution line parameters and environmental variables around the line, and establish a line dynamic capacity estimation model based on the principle of thermal balance to calculate the actual available capacity of the distribution line at different time periods;

[0007] Based on the operation constraints of the distribution network and distributed resources, an active distribution network model is established to characterize the output power flexibility range allowed for safe operation of the active distribution network; and

[0008] The actual available capacity of the distribution lines in different time periods is applied to the active distribution network model to obtain the distribution network output power flexibility range based on the dynamic line capacity.

[0009] Optionally, obtaining the measurement data of the distribution line parameters and the environmental variables around the line includes:

[0010] The distribution line parameters are obtained, and environmental variable measurement data at different times are collected, wherein the environmental variable measurement data include the measured values ​​of wind speed and ambient temperature around the distribution line, and the distribution line parameters include the guide radius of the distribution network line.

[0011] Optionally, the calculating the actual available capacity of the distribution line in different time periods includes:

[0012] The actual available capacity of the distribution line is obtained based on the steady-state transmission capacity of the distribution line multiplied by the environmental adjustment factor.

[0013] Optionally, the step of establishing an active distribution network model that depicts the output power flexibility range allowed for safe operation of the active distribution network includes:

[0014] Establish the output power flexibility range model of active distribution network and the operation model of active distribution network;

[0015] The active distribution network model is obtained based on the active distribution network output power flexibility range model and the dynamic distribution network operation model.

[0016] Optionally, applying the actual available capacity of the distribution lines in different time periods to the active distribution network model to obtain a distribution network output power flexibility range based on dynamic line capacity includes:

[0017] Determining the impact value of dynamic line capacity on the active distribution network model;

[0018] Based on the impact value, a dynamic capacity increase technology is used to generate an output power flexibility range of the active distribution network. A second aspect of the present application provides an active distribution network flexibility range calculation device considering dynamic capacity increase, including:

[0019] The calculation module is used to obtain the measurement data of the distribution line parameters and the environmental variables around the line, and to establish a line dynamic capacity estimation model based on the thermal balance principle to calculate the actual available capacity of the distribution line in different time periods;

[0020] Establishing a module for establishing an active distribution network model that characterizes the output power flexibility range allowed for safe operation of the active distribution network based on the operating constraints of the distribution network and distributed resources; and

[0021] The acquisition module is used to apply the actual available capacity of the distribution line in different time periods to the active distribution network model to obtain the distribution network output power flexibility range based on the dynamic line capacity.

[0022] Optionally, the calculation module is specifically used to:

[0023] The distribution line parameters are obtained, and environmental variable measurement data at different times are collected, wherein the environmental variable measurement data include the measured values ​​of wind speed and ambient temperature around the distribution line, and the distribution line parameters include the guide radius of the distribution network line.

[0024] Optionally, the calculation module is specifically used to:

[0025] The actual available capacity of the distribution line is obtained based on the steady-state transmission capacity of the distribution line multiplied by the environmental adjustment factor.

[0026] Optionally, the establishing module is specifically used to:

[0027] Establish the output power flexibility range model of active distribution network and the operation model of active distribution network;

[0028] The active distribution network model is obtained based on the active distribution network output power flexibility range model and the dynamic distribution network operation model.

[0029] Optionally, the acquisition module is specifically used to:

[0030] Determining the impact value of dynamic line capacity on the active distribution network model;

[0031] Based on the impact value, a dynamic capacity increase technology is used to generate an output power flexibility range of the active power distribution network.

[0032] The third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the program to implement the method for calculating the flexibility range of an active distribution network taking into account dynamic capacity expansion as described in the above embodiment.

[0033] The fourth aspect of the present application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the above-mentioned method for calculating the flexibility range of an active distribution network taking into account dynamic capacity expansion.

[0034] Therefore, by establishing a line dynamic capacity estimation model and method, the actual available capacity of the line with ambient temperature and wind speed variables is obtained, and the line dynamic capacity increase technology is applied to the distribution network operation model, which expands the flexibility range of the distribution network output power and enhances the ability of the distribution network to provide flexible support for the transmission network, thereby improving the operating economy and safety of the active power grid without increasing line investment.

[0035] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0037] Figure 1A flowchart of a method for calculating the flexibility range of an active distribution network considering dynamic capacity increase provided according to an embodiment of the present application;

[0038] Figure 2 A schematic diagram of a calculation process of dynamic line capacity according to an embodiment of the present application;

[0039] Figure 3 An exemplary diagram of a device for calculating the flexibility range of an active distribution network considering dynamic capacity increase according to an embodiment of the present application;

[0040] Figure 4 is an exemplary diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0041] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0042] The following describes a method and device for calculating the flexibility range of an active distribution network considering dynamic capacity expansion in an embodiment of the present application with reference to the accompanying drawings.

[0043] Before introducing the method for calculating the flexibility range of an active distribution network considering dynamic capacity expansion according to an embodiment of the present application, some methods in related technologies are briefly introduced.

[0044] When describing the output power flexibility range of the active distribution network in the related technologies, the impact of the dynamic line capacity on the output range is not considered; and the related technologies propose to evaluate the operating status of the entire active distribution network according to the operating status of different feeder systems, but do not consider the application of dynamic line capacity to increase the output power of the active distribution network. Regarding the expansion effect of dynamic capacity increase technology on line transmission capacity, the existing methods propose an estimation model for dynamic line capacity and analyze the expansion effect of dynamic line capacity, but do not propose the application of dynamic capacity increase technology in the transmission and distribution dispatching operation of the power system.

[0045] Therefore, in order to expand the flexibility range of the output power of the active distribution network, the present application provides a method for calculating the flexibility range of the active distribution network taking into account dynamic capacity expansion. In this method, by establishing a line dynamic capacity estimation model and method, the actual available capacity of the line that varies with ambient temperature and wind speed variables is obtained, and the line dynamic capacity expansion technology is applied to the distribution network operation model to expand the flexibility range of the distribution network output power, and enhance the ability of the distribution network to provide flexibility support for the transmission network, thereby improving the operating economy and safety of the active power grid without increasing line investment.

[0046] Specifically, Figure 1 A flowchart of a method for calculating the flexibility range of an active distribution network taking into account dynamic capacity expansion provided in an embodiment of the present application.

[0047] like Figure 1 As shown, the method for calculating the flexibility range of the active distribution network considering dynamic capacity increase includes the following steps:

[0048] In step S101, the measured data of the distribution line parameters and the environmental variables around the line are obtained, and a line dynamic capacity estimation model is established based on the thermal balance principle to calculate the actual available capacity of the distribution line in different time periods.

[0049] Specifically, the principle of dynamic capacity expansion technology is: the line transmission capacity is determined by the thermal stability limit of the conductor, and the thermal stability is affected by a large number of environmental factors. Therefore, the maximum allowable line current capacity changes with environmental conditions, which is the dynamic line capacity. In general, environmental conditions are relatively good, so the dynamic line capacity is generally higher than the steady-state line capacity estimated under conservative conditions. Whether in normal conditions or in accident conditions, dynamic line capacity plays an effective role in expanding line capacity and alleviating line congestion.

[0050] Optionally, in some embodiments, obtaining distribution line parameters and measurement data of environmental variables around the lines includes: acquiring distribution line parameters, and collecting environmental variable measurement data at different times, wherein the environmental variable measurement data include measurement values ​​of wind speed and ambient temperature around the distribution lines, and the distribution line parameters include the guide radius of the distribution network lines and the steady-state transmission capacity (SLR) of the distribution lines.

[0051] Optionally, in some embodiments, calculating the actual available capacity of the distribution line in different time periods includes: obtaining the actual available capacity of the distribution line based on the steady-state transmission capacity of the distribution line and multiplying it by an environmental adjustment factor.

[0052] Furthermore, a line dynamic capacity estimation model is established: The dynamic line rating (DLR) calculation model is based on the steady-state thermal balance model of the line conductor. The calculation process is as follows: Figure 2 As shown. This application mainly considers the impact of two variables, wind speed and external temperature, on the line dynamic capacity, and believes that the impact of wind speed and temperature on line capacity is independent. Therefore, DLR can be regarded as a function of line SLR, ambient temperature, and wind speed. Based on the line SLR, the line DLR is obtained by multiplying the environmental adjustment factor η(v,T). The calculation formula of the environmental adjustment factor is:

[0053]

[0054] Among them, v represents the wind speed, T represents the ambient temperature, and because the effects of wind speed and temperature are independent of each other, η(v,T) can be decomposed into the wind speed related factor η v and the temperature-dependent factor η T Assume that the steady-state line capacity of line ij is Through calculation or detection data, the corresponding dynamic line capacity is Since the calculation of wind speed related factors is different under low wind speed and high wind speed, η is used. low(v) The wind speed correlation factor at low wind speed is represented by η hig h(v) will represent the correlation factor at high wind speeds, while η v Not less than 1, and its calculation formula is:

[0055]

[0056] in, v SLR is the wind speed for determining SLR, and its typical value is v SLR =0.5m / s. The calculation formulas for other parameters are:

[0057]

[0058]

[0059]

[0060] Among them, T film =T c -T A , T c is the line conductor temperature, T A is the ambient temperature around the circuit, H e is the altitude, D is the wire diameter. Parameter μ f and ρ f are the air viscosity and air density respectively.

[0061] Temperature-dependent factor η T The calculation formula is:

[0062]

[0063] in, VT=T c -T A , T c is the temperature of the line conductor, T A is the temperature of the environment, is the ambient temperature under SLR conditions. Therefore, the environmental adjustment factor can be calculated by the following formula:

[0064] In step S102, based on the operation constraints of the distribution network and distributed resources, an active distribution network model is established to characterize the output power flexibility range allowed for the safe operation of the active distribution network.

[0065] Optionally, in some embodiments, an active distribution network model is established that characterizes the output power flexibility range allowed for the safe operation of the active distribution network, including: establishing an active distribution network output power flexibility range model and an active distribution network operation model; and obtaining the active distribution network model based on the active distribution network output power flexibility range model and the active distribution network operation model.

[0066] Specifically, the embodiment of the present application can construct an active distribution network model based on distribution network constraints and distributed resource constraints.

[0067] Among them, for the active distribution network output power flexibility range model:

[0068] make Represents the active power and reactive power output of the active distribution network, which is the actual electrical power exchanged at the substations of the distribution network. It is defined as a vector of N control variables inside the distribution network. The internal control variables include DER power output, node voltage amplitude and voltage phase. Under DER operation restrictions and network security constraints, the feasible region of (x, y) is the output power flexibility range of the active distribution network, defined as Ω, which is a subset of the high-dimensional vector space. In order to describe the output power flexibility provision capability of the active distribution network, Ω is projected onto the subspace of x to obtain the output power flexibility range of the active distribution network. Mathematically, the output power flexibility range of the active distribution network is defined as follows:

[0069]

[0070] The output power flexibility range of the active distribution network is the projected area, which is low-dimensional and can be embedded in the transmission layer scheduling model without showing the specific internal system information. For each output power flexibility range model of the active distribution network, the transmission layer optimization scheduling model combined with the flexibility of DER can be expressed in the following form:

[0071]

[0072]

[0073]

[0074] in, They represent the power output of the mth centralized generator and the nth active distribution network respectively. C(·) represents the corresponding cost curve. The active distribution network can strategically bid in the transmission layer market to maximize the network benefits. Formula (7) indicates that the active distribution network meets the safe operation conditions of the transmission system and centralized generators, and h(·)≤0 represents the safe operation constraints of the active distribution network and centralized power plants. The set N contains the subscripts of all active distribution networks participating in the transmission layer optimization.

[0075] The transmission layer’s dispatching demand for the active distribution network is set as The distribution layer allocation model can be expressed as:

[0076]

[0077]

[0078] Among them, C dist (·) represents the operating cost, distribution network loss, etc. Because the feasible domain of the active distribution network Φ n Determined in the transmission layer scheduling model, therefore, the scheduling of the distribution layer needs to ensure that for a given active distribution network planning demand It is feasible.

[0079] For active distribution network operation model:

[0080] The distribution network constraint expression is:

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088] In the above model, i and j are the node labels of the network, ij is the branch from node i to node j, and are the node number set and line number set respectively. Equations (11) and (12) represent the power flow equations of the line, where and are the active power and reactive power of line ij respectively. iis the voltage at node i, θ ij is the potential phase difference between nodes i and j. Constant g ij and b ij are the conductance and susceptance of line ij, respectively. Equation (13) represents the transmission capacity constraints of lines and transformers in the distribution network. is the upper limit of the transformer capacity, P0 and Q0 are the active power and reactive power of the transformer respectively. is the current carrying capacity of line ij. Equations (14) and (15) represent the node power balance, where P i g and P i d are the generating active power and the load active power respectively, and They are generation reactive power and load reactive power respectively. are the active power and reactive power of node j with transformer in the network, is the set of labels of nodes with transformers. Equation (17) represents the upper and lower limit constraints of node voltage. The operating characteristics of distributed resources (DER) are expressed as Equation (16), where X i It is represented as the capacity curve of the i-th DER.

[0089] The main constraints of distributed resources are as follows:

[0090]

[0091]

[0092]

[0093] Among them, equation (18) represents the capacity limit of the i-th DER, equation (19) represents the upper and lower limits of the active power and reactive power output of the i-th DER, and equation (20) represents that the power factor angle of DER needs to be limited within certain upper and lower limits. The constraint model of DER can represent adjustable loads, distributed generators and renewable energy generation, such as photovoltaic power generation (PV).

[0094] In step S103, the actual available capacity of the distribution lines in different time periods is applied to the active distribution network model to obtain the distribution network output power flexibility range based on the dynamic line capacity.

[0095] Optionally, in some embodiments, the actual available capacity of the distribution lines in different time periods is applied to the active distribution network model to obtain the distribution network output power flexibility range based on the dynamic line capacity, including: determining the impact value of the dynamic line capacity on the active distribution network model; based on the impact value, using dynamic capacity expansion technology to generate the output power flexibility range of the active distribution network.

[0096] Specifically, the embodiments of the present application may consider the calculation of the flexibility range of the active distribution network of the dynamic capacity expansion technology.

[0097] (1) The impact of dynamic line capacity on the active distribution network model is as follows:

[0098] The dynamic capacity increase technology mainly changes the current carrying capacity of the line, thereby changing the line capacity constraints in the active distribution network model, and then obtaining the output power flexibility range of the active distribution network under different line capacities. The specific constraints affected by the dynamic line capacity are:

[0099]

[0100] in, is the current carrying capacity of line ij, let That is, the dynamic line capacity is applied to the calculation of the output power flexibility range of the active distribution network.

[0101] (2) Using dynamic capacity expansion technology to expand the output power flexibility of the active distribution network is as follows:

[0102] The study shows that when DLR is considered, the output power flexibility range of the active distribution network increases. In the period when the dynamic line capacity is higher than the steady-state line capacity, the active distribution network can provide more flexible supply. The degree of increase in the feasible domain area is basically consistent with the degree of change in the DLR adjustment factor, that is, when the DLR adjustment factor is equal to 1, the output power flexibility range of the active distribution network when considering DLR and when not considering DLR is the same. When the DLR adjustment factor is greater than 1, the feasible domain range also increases. However, when the DLR adjustment factor is the largest, the feasible domain output is not necessarily the largest, because the degree of change in the feasible domain is not only related to the degree of increase in line capacity, but also to factors such as distributed resource generation and load demand. In general, the use of dynamic capacity expansion technology can alleviate line congestion, increase the output of the active distribution network and promote the utilization of distributed resources.

[0103] In summary, the embodiments of the present application can first obtain the measurement data of the distribution line parameters and the environmental variables around the line, establish a line dynamic capacity estimation model based on the principle of thermal balance, and calculate the actual available capacity of the distribution line in different time periods. Secondly, based on the operating constraints of the distribution network and distributed resources, an active distribution network scheduling model is established to characterize the output power flexibility range allowed for the safe operation of the active distribution network. Finally, the actual available capacity of the line obtained based on the dynamic capacity increase calculation is applied to the active distribution network operation model to obtain the output power flexibility range of the distribution network based on the dynamic line capacity, thereby increasing the transmission capacity of the distribution line, expanding the output power flexibility range of the active distribution network, and improving the operation economy and safety of the power grid without increasing line investment.

[0104] According to the method for calculating the flexibility range of the active distribution network considering dynamic capacity expansion proposed in the embodiment of the present application, by establishing a line dynamic capacity estimation model and method, the actual available capacity of the line that varies with ambient temperature and wind speed variables is obtained, and the line dynamic capacity expansion technology is applied to the distribution network operation model, so as to expand the output power flexibility range of the distribution network, enhance the ability of the distribution network to provide flexibility support for the transmission network, and thereby improve the operating economy and safety of the active power grid without increasing line investment.

[0105] Next, a device for calculating the flexibility range of an active distribution network taking into account dynamic capacity expansion proposed in an embodiment of the present application will be described with reference to the accompanying drawings.

[0106] Figure 3 It is a block diagram of an active distribution network flexibility range calculation device considering dynamic capacity expansion according to an embodiment of the present application.

[0107] like Figure 3 As shown, the active distribution network flexibility range calculation device 10 considering dynamic capacity increase includes: a calculation module 100, an establishment module 200 and an acquisition module 300.

[0108] The calculation module 100 is used to obtain the measurement data of the distribution line parameters and the environmental variables around the line, and establish a line dynamic capacity estimation model based on the thermal balance principle to calculate the actual available capacity of the distribution line in different time periods;

[0109] The building module 200 is used to build an active distribution network model that describes the output power flexibility range allowed for safe operation of the active distribution network based on the operation constraints of the distribution network and distributed resources; and

[0110] The acquisition module 300 is used to apply the actual available capacity of the distribution lines in different time periods to the active distribution network model to obtain the distribution network output power flexibility range based on the dynamic line capacity.

[0111] Wherein, optionally, the calculation module 100 is specifically used for:

[0112] The distribution line parameters are obtained, and the environmental variable measurement data at different times are collected, wherein the environmental variable measurement data include the measured values ​​of the wind speed and the ambient temperature around the distribution line, and the distribution line parameters include the guide radius of the distribution network line.

[0113] Optionally, the calculation module 100 is specifically used for:

[0114] The actual available capacity of the distribution line is obtained based on the steady-state transmission capacity of the distribution line and multiplied by the environmental adjustment factor.

[0115] Optionally, the establishment module 200 is specifically used for:

[0116] Establish the output power flexibility range model of active distribution network and the operation model of active distribution network;

[0117] The active distribution network model is obtained based on the output power flexibility range model of the active distribution network and the dynamic distribution network operation model.

[0118] Optionally, the acquisition module 300 is specifically used for:

[0119] Determine the impact of dynamic line capacity on active distribution network models;

[0120] Based on the impact value, the output power flexibility range of the active distribution network is generated using dynamic capacity increase technology.

[0121] It should be noted that the aforementioned explanation of the embodiment of the method for calculating the flexibility range of an active distribution network considering dynamic capacity expansion is also applicable to the device for calculating the flexibility range of an active distribution network considering dynamic capacity expansion of this embodiment, and will not be repeated here.

[0122] According to the active distribution network flexibility range calculation device considering dynamic capacity expansion proposed in the embodiment of the present application, by establishing a line dynamic capacity estimation model and method, the actual available capacity of the line that varies with ambient temperature and wind speed variables is obtained, and the line dynamic capacity expansion technology is applied to the distribution network operation model to increase the transmission capacity of the distribution line, expand the output power flexibility range of the distribution network, and enhance the ability of the distribution network to provide flexibility support for the transmission network, thereby improving the operating economy and safety of the active power grid without increasing line investment.

[0123] Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0124] Memory 401 , processor 402 , and a computer program stored in the memory 401 and executable on the processor 402 .

[0125] When the processor 402 executes the program, the method for calculating the flexibility range of the active distribution network considering dynamic capacity increase provided in the above-mentioned embodiment is implemented.

[0126] Furthermore, the electronic device further comprises:

[0127] The communication interface 403 is used for communication between the memory 401 and the processor 402 .

[0128] The memory 401 is used to store computer programs that can be run on the processor 402 .

[0129] The memory 401 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0130] If the memory 401, the processor 402 and the communication interface 403 are implemented independently, the communication interface 403, the memory 401 and the processor 402 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 4 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0131] Optionally, in a specific implementation, if the memory 401, the processor 402 and the communication interface 403 are integrated on a chip, the memory 401, the processor 402 and the communication interface 403 can communicate with each other through an internal interface.

[0132] The processor 402 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0133] This embodiment also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned method for calculating the flexibility range of an active distribution network taking into account dynamic capacity increase.

[0134] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they contradict each other.

[0135] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0136] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0137] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0138] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0139] A person skilled in the art may understand that all or part of the steps in the method of the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0140] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0141] The storage medium mentioned above may be a read-only memory, a disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for calculating the flexibility range of an active distribution network considering dynamic capacity expansion, characterized in that: The following steps are involved: Obtain the measured data of distribution line parameters and environmental variables around the line, and establish a line dynamic capacity estimation model based on the principle of thermal balance to calculate the actual available capacity of the distribution line at different time periods; Based on the operation constraints of the distribution network and distributed resources, an active distribution network model is established to characterize the output power flexibility range allowed for the safe operation of the active distribution network. as well as Applying the actual available capacity of the distribution lines in different time periods to the active distribution network model to obtain a distribution network output power flexibility range based on dynamic line capacity; Wherein, the establishment of an active distribution network model that depicts the output power flexibility range allowed for safe operation of the active distribution network includes: establishing an active distribution network output power flexibility range model and an active distribution network operation model; obtaining the active distribution network model based on the active distribution network output power flexibility range model and the active distribution network operation model; The line dynamic capacity estimation model is: Among them, η(v,T) is the environmental adjustment factor, v is the wind speed, T is the ambient temperature, is the dynamic line capacity of line ij, is the steady-state line capacity of line ij; Among them, for the active distribution network output power flexibility range model: make Represents the active power and reactive power output of the active distribution network, which is the actual electrical power exchanged at the substations of the distribution network. It is defined as a vector composed of N control variables inside the distribution network. The internal control variables include DER power output, node voltage amplitude and voltage phase. Under the DER operation restrictions and network security constraints, the feasible region of (x, y) is the output power flexibility range of the active distribution network, defined as Ω. This region is a subset of the high-dimensional vector space. In order to describe the output power flexibility provision capability of the active distribution network, Ω is projected onto the subspace of x to obtain the output power flexibility range of the active distribution network. Mathematically, the output power flexibility range of the active distribution network is defined as follows: The method of applying the actual available capacity of the distribution lines in different time periods to the active distribution network model to obtain the distribution network output power flexibility range based on the dynamic line capacity includes: determining the impact value of the dynamic line capacity on the active distribution network model; and generating the output power flexibility range of the active distribution network by using the dynamic capacity increase technology based on the impact value.

2. The method according to claim 1, characterized in that The obtaining of the measurement data of the distribution line parameters and the environmental variables around the line includes: The distribution line parameters are obtained, and environmental variable measurement data at different times are collected, wherein the environmental variable measurement data include the measured values ​​of wind speed and ambient temperature around the distribution line, and the distribution line parameters include the guide radius of the distribution network line.

3. The method according to claim 1 or 2, characterized in that: The calculation of the actual available capacity of the distribution line in different time periods includes: The actual available capacity of the distribution line is obtained based on the steady-state transmission capacity of the distribution line multiplied by the environmental adjustment factor.

4. A device for calculating the flexibility range of an active distribution network considering dynamic capacity increase, characterized in that: include: The calculation module is used to obtain the measurement data of the distribution line parameters and the environmental variables around the line, and to establish a line dynamic capacity estimation model based on the thermal balance principle to calculate the actual available capacity of the distribution line in different time periods; Establish a module for establishing an active distribution network model that characterizes the output power flexibility range allowed for safe operation of the active distribution network based on the operation constraints of the distribution network and distributed resources; as well as An acquisition module, used for applying the actual available capacity of the distribution lines in different time periods to the active distribution network model to obtain a distribution network output power flexibility range based on dynamic line capacity; Wherein, the establishment module is specifically used to: establish an active distribution network output power flexibility range model and an active distribution network operation model; obtain the active distribution network model based on the active distribution network output power flexibility range model and the active distribution network operation model; The line dynamic capacity estimation model is: Among them, η(v,T) is the environmental adjustment factor, v is the wind speed, T is the ambient temperature, is the dynamic line capacity of line ij, is the steady-state line capacity of line ij; Among them, for the active distribution network output power flexibility range model: make Represents the active power and reactive power output of the active distribution network, which is the actual electrical power exchanged at the substations of the distribution network. It is defined as a vector composed of N control variables inside the distribution network. The internal control variables include DER power output, node voltage amplitude and voltage phase. Under the DER operation restrictions and network security constraints, the feasible region of (x, y) is the output power flexibility range of the active distribution network, defined as Ω. This region is a subset of the high-dimensional vector space. In order to describe the output power flexibility provision capability of the active distribution network, Ω is projected onto the subspace of x to obtain the output power flexibility range of the active distribution network. Mathematically, the output power flexibility range of the active distribution network is defined as follows: The acquisition module is specifically used to: determine the impact value of dynamic line capacity on the active distribution network model; based on the impact value, generate the output power flexibility range of the active distribution network using dynamic capacity expansion technology.

5. The device according to claim 4, characterized in that The computing module is specifically used for: The distribution line parameters are obtained, and environmental variable measurement data at different times are collected, wherein the environmental variable measurement data include the measured values ​​of wind speed and ambient temperature around the distribution line, and the distribution line parameters include the guide radius of the distribution network line.

6. The device according to claim 4 or 5, characterized in that The computing module is specifically used for: The actual available capacity of the distribution line is obtained based on the steady-state transmission capacity of the distribution line multiplied by the environmental adjustment factor.

7. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for calculating the flexibility range of an active distribution network taking into account dynamic capacity expansion as described in any one of claims 1 to 3.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement a method for calculating the flexibility range of an active distribution network taking into account dynamic capacity expansion as described in any one of claims 1 to 3.

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