Power distribution network area interconnection adjustment method and device, computer equipment and storage medium

Abstract

The invention relates to a power distribution network area interconnection adjustment method and device, computer equipment and a storage medium. The method comprises the following steps: acquiring a load rate and a power clearance value of each transformer area in a power distribution network; the power distribution network comprises at least one transformer area cluster; the transformer area cluster comprises at least one group of interconnected transformer areas; the interconnection transformer area only comprises two transformer areas, and the two transformer areas are connected with each other through a flexible interconnection switch; selecting a transformer area with the highest load rate, and determining a target transformer area cluster to which the transformer area with the highest load rate belongs; for each transformer area in each group of interconnected transformer areas in the target transformer area cluster, determining the transformer area type of the transformer area according to the load rate and the power clearance value of the transformer area; and under the condition that the transformer area types of the two transformer areas in the target interconnection transformer area are consistent, the flexible interconnection switch is switched off. By adopting the method, the interconnection state among the transformer areas in the power distribution network can be dynamically adjusted, and the resource configuration and the operation efficiency are optimized, so that the flexibility and the reliability of the power grid are improved.

Description

Technical Field

[0001] The present application relates to the technical field of electrical automation, and particularly to a method, device, computer equipment, and storage medium for interconnected adjustment of distribution network substations. Background Art

[0002] The rapid development of power electronics technology has gradually made low-voltage DC distribution networks an important direction for future distribution networks. Its high efficiency, reliability, and environmental friendliness give it significant advantages, including reducing line costs, decreasing power transmission losses, and enhancing the reliability of power supply. At the same time, to achieve the sharing and optimization of distribution substation resources, the technology of interconnected distribution substations has become a research focus in academia and industry, especially the flexible interconnection technology based on power electronics. This technology can be integrated with distributed new energy and battery energy storage systems and bring considerable economic benefits, enabling the power grid to achieve self-sufficiency with minimal dependence on the external power grid and further enhancing flexibility and stability.

[0003] However, in distribution networks with a high penetration of distributed new energy, the widespread application of power electronic devices has significantly increased the complexity of power grid operation and management. Although DC distribution networks can reduce system losses and improve power grid reliability, with the dynamic changes of new energy and loads, how to adjust the interconnected state of substations according to real-time data to improve the transformer load rate and enhance the new energy integration ability has become a key problem to be solved urgently. Summary of the Invention

[0004] Based on this, it is necessary to provide a method, device, computer equipment, and storage medium for interconnected adjustment of distribution network substations that can adjust the interconnected state of substations to solve the above technical problems.

[0005] In a first aspect, the present application provides a method for interconnected adjustment of distribution network substations, including:

[0006] Obtaining the load rate and power surplus / deficit value of each substation in the distribution network; the distribution network includes at least one substation cluster; the substation cluster includes at least one group of interconnected substations; the interconnected substations only contain two substations, and the two substations are connected to each other through a flexible connection switch;

[0007] Selecting the substation with the highest load rate and determining the target substation cluster to which the substation with the highest load rate belongs;

[0008] For each substation in each group of interconnected substations within the target substation cluster, determining the substation type of the substation according to the load rate and power surplus / deficit value of the substation;

[0009] When the substation types of the two substations in the target interconnected substations are the same, disconnecting the flexible connection switch.

[0010] In one embodiment, the substation area type includes a load type and a power surplus / deficit type; determining the substation area type of the substation area according to the load rate and the power surplus / deficit value of the substation area includes:

[0011] Determining the load type of the substation area according to the magnitude relationship between the load rate of the substation area and a preset load rate threshold; and,

[0012] Determining the power surplus / deficit type of the substation area according to the magnitude relationship between the power surplus / deficit value of the substation area and a preset surplus / deficit value threshold.

[0013] In one embodiment, obtaining the load rate and the power surplus / deficit value of each substation area in the distribution network includes:

[0014] For each substation area, obtaining the maximum net load of the substation area, the substation area power, and the rated capacity of the transformer in the substation area; the substation area power includes the active power and reactive power flowing out of the distribution network from the substation area, the net power of the energy storage power station connected to the substation area, and the transmission power of the interconnected line in the target interconnected substation area corresponding to the substation area;

[0015] Taking the power difference between the sum of powers and the charging power as the power surplus / deficit value of the substation area; the sum of powers is the sum value between the maximum net load and the net power; and,

[0016] Determining the load rate of the substation area according to the active power, reactive power, and rated capacity.

[0017] In one embodiment, obtaining the maximum net load of the substation area includes:

[0018] Obtaining the photovoltaic power of the photovoltaic power station connected to the substation area, the wind power of the wind power station connected to the substation area, and the active power consumed by the DC electrical equipment in the substation area;

[0019] Determining the sum value between the photovoltaic power and the wind power as the received power of the substation area;

[0020] Taking the difference between the received power and the active power consumed by the DC electrical equipment in the substation area as the maximum net load of the substation area.

[0021] In one embodiment, the method for obtaining the wind power of the wind power station connected to the substation area includes:

[0022] Obtaining the rated power of the wind power station connected to the substation area, the wind speed parameters, and the current wind speed within the current time period; the wind speed parameters include the rated wind speed, cut-in wind speed, and cut-out wind speed of the wind power station;

[0023] Based on the magnitude relationship between the current wind speed and the wind speed parameters, determining the wind power of the wind power station connected to the substation area according to the rated power of the wind power station.

[0024] In one embodiment, obtaining the active power flowing out of the distribution network from the substation area includes:

[0025] Obtain the active power flowing through the transformer area converter in the distribution network, the active power consumed by the AC electrical equipment in the transformer area, and the diagonal matrix of the distribution network;

[0026] Determine the active power flowing out of the distribution network from the transformer area under the power balance constraint according to the diagonal matrix of the distribution network;

[0027] Among them, the power balance constraint includes at least one of the following: the active power flowing out of the distribution network from the transformer area is balanced with the sum of the active power flowing through the transformer area converter in the distribution network and the active power consumed by the AC electrical equipment in the transformer area; the power generation power of the distribution network and the power consumption power of the distribution network are balanced; the power generation power is the sum of the active power flowing through the transformer area converter in the distribution network, the photovoltaic power, and the wind power; the power consumption power is the sum of the active power consumed by the DC electrical equipment in the transformer area, the net power of the energy storage power station connected to the transformer area, and the transmission power of the interconnection line in the corresponding target interconnection transformer area of the transformer area.

[0028] In a second aspect, the present application also provides a distribution network transformer area interconnection adjustment device, including:

[0029] An acquisition module, configured to acquire the load rate and power surplus / deficit value of each transformer area in the distribution network; the distribution network includes at least one transformer area cluster; the transformer area cluster includes at least one group of interconnected transformer areas; the interconnected transformer areas only include two transformer areas, and the two transformer areas are connected to each other through a flexible connection switch;

[0030] A selection module, configured to select the transformer area with the highest load rate and determine the target transformer area cluster to which the transformer area with the highest load rate belongs;

[0031] A type module, configured to determine the type of each transformer area in each group of interconnected transformer areas in the target transformer area cluster according to the load rate and power surplus / deficit value of the transformer area;

[0032] A disconnection module, configured to disconnect the flexible connection switch when the types of the two transformer areas in the target interconnected transformer area are the same.

[0033] In a third aspect, the present application also provides a computer device, including a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0034] Acquire the load rate and power surplus / deficit value of each transformer area in the distribution network; the distribution network includes at least one transformer area cluster; the transformer area cluster includes at least one group of interconnected transformer areas; the interconnected transformer areas only include two transformer areas, and the two transformer areas are connected to each other through a flexible connection switch;

[0035] Select the transformer area with the highest load rate and determine the target transformer area cluster to which the transformer area with the highest load rate belongs;

[0036] For each substation area in each group of interconnected substation areas within the target substation area cluster, determine the type of the substation area according to the load rate and power surplus / deficit value of the substation area.

[0037] When the types of the two substation areas in the target interconnected substation areas are the same, disconnect the flexible connection switch.

[0038] Fourthly, the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0039] Obtain the load rate and power surplus / deficit value of each substation area in the distribution network; the distribution network includes at least one substation area cluster; the substation area cluster includes at least one group of interconnected substation areas; the interconnected substation areas only contain two substation areas, and the two substation areas are connected to each other through a flexible connection switch.

[0040] Select the substation area with the highest load rate, and determine the target substation area cluster to which the substation area with the highest load rate belongs.

[0041] For each substation area in each group of interconnected substation areas within the target substation area cluster, determine the type of the substation area according to the load rate and power surplus / deficit value of the substation area.

[0042] When the types of the two substation areas in the target interconnected substation areas are the same, disconnect the flexible connection switch.

[0043] Fifthly, the present application also provides a computer program product, including a computer program. When the computer program is executed by a processor, the following steps are implemented:

[0044] Obtain the load rate and power surplus / deficit value of each substation area in the distribution network; the distribution network includes at least one substation area cluster; the substation area cluster includes at least one group of interconnected substation areas; the interconnected substation areas only contain two substation areas, and the two substation areas are connected to each other through a flexible connection switch.

[0045] Select the substation area with the highest load rate, and determine the target substation area cluster to which the substation area with the highest load rate belongs.

[0046] For each substation area in each group of interconnected substation areas within the target substation area cluster, determine the type of the substation area according to the load rate and power surplus / deficit value of the substation area.

[0047] When the types of the two substation areas in the target interconnected substation areas are the same, disconnect the flexible connection switch.

[0048] The above method, device, computer equipment and storage medium for interconnected adjustment of distribution network substations obtain the load rate and power surplus / deficit value of each substation in the distribution network; the distribution network includes at least one substation cluster; the substation cluster includes at least one group of interconnected substations; the interconnected substations only contain two substations, and the two substations are connected to each other through a flexible connection switch; select the substation with the highest load rate, and determine the target substation cluster to which the substation with the highest load rate belongs; for each substation in each group of interconnected substations in the target substation cluster, determine the substation type of the substation according to the load rate and power surplus / deficit value of the substation; when the substation types of the two substations in the target interconnected substations are the same, disconnect the flexible connection switch. This embodiment can dynamically adjust the interconnection state between substations in the distribution network according to the load rate and power surplus / deficit value of each substation in the distribution network, optimize resource allocation and operation efficiency, so as to improve the flexibility and reliability of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0050] Figure 1 It is an application environment diagram of a method for interconnected adjustment of distribution network substations provided in this embodiment;

[0051] Figure 2A It is a flowchart of a method for interconnected adjustment of distribution network substations provided in this embodiment;

[0052] Figure 2B It is a schematic diagram of the topology structure of a distribution network provided in this embodiment;

[0053] Figure 3 It is a flowchart of the steps for determining the substation type provided in this embodiment;

[0054] Figure 4 It is a flowchart of the steps for obtaining the maximum net load provided in this embodiment;

[0055] Figure 5 It is a flowchart of the steps for obtaining the load rate and power surplus / deficit value provided in this embodiment;

[0056] Figure 6 It is a block diagram of the structure of a device for interconnected adjustment of distribution network substations provided in this embodiment;

[0057] Figure 7 It is an internal structure diagram of a computer device provided in this embodiment. Detailed implementation manners

[0058] In order to make the objectives, technical solutions, and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0059] The method for interconnected adjustment of distribution network substations provided by the embodiments of the present application can be applied to an application environment as Figure 1 shown. Among them, the terminal 102 communicates with the server 104 through a network. The data storage system can store the data that the server 104 needs to process. The data storage system can be integrated on the server 104, or can be placed in the cloud or other network servers. The computer device obtains the load rate and power surplus / deficit value of each substation in the distribution network; the distribution network includes at least one substation cluster; the substation cluster includes at least one group of interconnected substations; the interconnected substations only contain two substations, and the two substations are connected to each other through a flexible connection switch; select the substation with the highest load rate, and determine the target substation cluster to which the substation with the highest load rate belongs; for each substation in each group of interconnected substations within the target substation cluster, determine the substation type of the substation according to the load rate and power surplus / deficit value of the substation; when the substation types of the two substations in the target interconnected substations are the same, disconnect the flexible connection switch. Among them, the computer device can be either a terminal or a server. The terminal 102 can be, but is not limited to, various personal computers, laptop computers, smart phones, tablet computers, Internet of Things devices, and portable wearable devices. The Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, etc. The portable wearable devices can be smart watches, smart bracelets, head-mounted devices, etc. The server 104 can be implemented by an independent server or a server cluster composed of multiple servers.

[0060] In an exemplary embodiment, as Figure 2A shown, a method for interconnected adjustment of distribution network substations is provided. Taking the method applied to the Figure 1 computer device as an example, the method includes the following steps S201 to S204. Among them:

[0061] S201, obtain the load rate and power surplus / deficit value of each substation in the distribution network.

[0062] Among them, the distribution network includes at least one substation cluster. The substation cluster includes at least one group of interconnected substations; the interconnected substations only contain two substations, and the two substations are connected to each other through a flexible connection switch. Among them, the power surplus / deficit value can be understood as the difference between the power generation power and the load demand power in the power system, reflecting the power balance state of the system at a certain moment.

[0063] Specifically, parameter information such as the topological structure, line parameters, load magnitude, and distributed new energy output of the distribution network is obtained. All interconnected substations are connected to soft switches, and the interconnection between substations is adjusted by the on / off of the switches. All interconnected substations are regarded as a substation cluster. After obtaining the parameter information such as the topological structure, line parameters, load magnitude, and distributed new energy output of the distribution network, the load rate and power surplus / deficit value of each substation in the distribution network are determined according to the parameter information.

[0064] S202, select the substation with the highest load rate, and determine the target substation cluster to which the substation with the highest load rate belongs.

[0065] Specifically, select the substation with the highest load rate from each substation, and use the substation cluster where this substation is located as the target cluster.

[0066] S203, for each substation in each group of interconnected substations within the target substation cluster, determine the substation type of the substation according to the load rate and power surplus / deficit value of the substation.

[0067] Specifically, for each substation in each group of interconnected substations within the target substation cluster, if the load rate of the substation is not less than 80%, then this substation is regarded as a heavily overloaded substation; conversely, if the load rate of the substation is less than 80%, then this substation is regarded as a normally operating substation; if the power surplus / deficit value of the substation is greater than 0, then this substation is regarded as a power surplus substation; conversely, if the load rate of the substation is not greater than 0, then this substation is regarded as a power deficit substation.

[0068] It should be noted that the load magnitude of the distribution substation and the output of the distributed new energy connected thereto have random fluctuations, resulting in different load rate conditions and power surplus / deficit conditions for each moment of the distribution substation. Therefore, the substations are classified according to the actual conditions of each substation at each moment, and the state of the flexible interconnection switch is adjusted in real time according to the classification conditions.

[0069] S204, when the substation types of two substations in the target interconnected substations are the same, disconnect the flexible connection switch.

[0070] Among them, the flexible connection switch can be understood as a new type of intelligent power electronic device installed at the traditional connection switch.

[0071] Specifically, when the load types of the two regions in the target interconnected substation area are the same and the power surplus / deficit types are also the same, it is determined that the substation area types of the two regions in the target interconnected substation area are the same; when the substation area types of the two regions in the target interconnected substation area are the same, the flexible connection switch is disconnected. When the load types of the two regions in the target interconnected substation area are different or the power surplus / deficit types are different, it is determined that the substation area types of the two regions in the target interconnected substation area are different; when the substation area types of the two regions in the target interconnected substation area are different, the flexible connection switch is turned on.

[0072] Exemplarily, as Figure 2B shown in the schematic diagram of the distribution network topology, the black dots in the figure represent substation areas, the black lines represent the connections of the distribution network, the blue lines represent the connections of the flexible connection switches, and the gray areas represent substation area clusters. Taking substation area cluster 1 (i.e., the cluster 1 shown in the figure) as an example, there is a connection of the distribution network (i.e., black line connection) between substation area 19 (black dot 19) and substation area 20 (black dot 20), and there is also a connection of the flexible connection switch (i.e., blue line connection); while there is no connection of the distribution network (i.e., no black line connection) between substation area 20 (black dot 20) and substation area 4 (black dot 4), but there is a connection of the flexible connection switch (i.e., blue line connection).

[0073] For the above distribution network substation area interconnection adjustment method, device, computer device and storage medium, the load rate and power surplus / deficit value of each substation area in the distribution network are obtained; the distribution network includes at least one substation area cluster; the substation area cluster includes at least one group of interconnected substation areas; the interconnected substation areas only contain two substation areas, and the two substation areas are connected to each other through a flexible connection switch; the substation area with the highest load rate is selected, and the target substation area cluster to which the substation area with the highest load rate belongs is determined; for each substation area in each group of interconnected substation areas in the target substation area cluster, according to the load rate and power surplus / deficit value of the substation area, the substation area type of the substation area is determined; when the substation area types of the two substation areas in the target interconnected substation area are the same, the flexible connection switch is disconnected. This embodiment can dynamically adjust the interconnection state between each substation area in the distribution network according to the load rate and power surplus / deficit value of each substation area in the distribution network, optimize resource allocation and operation efficiency, thereby improving the flexibility and reliability of the power grid.

[0074] Figure 3 It is a flow chart of the steps for determining the substation area type in an embodiment. This embodiment details the steps of determining the substation area type of the substation area according to the load rate and power surplus / deficit value of the substation area in the above embodiment. This embodiment gives an optional way of the steps for determining the substation area type, including the following steps:

[0075] S301, determine the load type of the substation area according to the magnitude relationship between the load rate of the substation area and the preset load rate threshold.

[0076] Specifically, if the load rate of the substation area is greater than the preset load rate threshold, it is determined that the load type of the substation area is a heavily overloaded substation area; if the load rate of the substation area is not greater than the preset load rate threshold, it is determined that the load type of the substation area is a normally operating substation area.

[0077] S302. Determine the power surplus / deficit type of the substation area according to the magnitude relationship between the power surplus / deficit value of the substation area and the preset surplus / deficit value threshold.

[0078] Specifically, if the power surplus / deficit value of the substation area is greater than the preset surplus / deficit value threshold, it is determined that the load type of the substation area is a power surplus substation area; if the power surplus / deficit value of the substation area is not greater than the preset surplus / deficit value threshold, it is determined that the load type of the substation area is a power deficit substation area.

[0079] In the above embodiment, the load type of the substation area is determined according to the magnitude relationship between the load rate of the substation area and the preset load rate threshold; the power surplus / deficit type of the substation area is determined according to the magnitude relationship between the power surplus / deficit value of the substation area and the preset surplus / deficit value threshold, and the substation area type of the substation area can be accurately determined.

[0080] Figure 4 It is a schematic flow chart of the maximum net load acquisition step in an embodiment. This embodiment refines the step of obtaining the maximum net load of the substation area in the above embodiment. This embodiment gives an optional way of the maximum net load acquisition step, including the following steps:

[0081] S401. Obtain the photovoltaic power of the photovoltaic power station connected to the substation area, the wind power of the wind power station connected to the substation area, and the active power consumed by the DC electrical equipment in the substation area.

[0082] Specifically, obtain the rated power of the wind power station connected to the substation area, the wind speed parameters, and the current wind speed within the current time period; the wind speed parameters include the rated wind speed, cut-in wind speed, and cut-out wind speed of the wind power station; based on the magnitude relationship between the current wind speed and the wind speed parameters, determine the wind power of the wind power station connected to the substation area according to the rated power of the wind power station.

[0083] Specifically, obtain the active power flowing through the substation converter in the distribution network, the active power consumed by the AC electrical equipment within the substation, and the diagonal matrix of the distribution network; according to the diagonal matrix of the distribution network, under the power balance constraint, determine the active power flowing out of the distribution network from the substation; where the power balance constraint includes at least one of the following: the active power flowing out of the distribution network is balanced with the sum of the active power flowing through the substation converter in the distribution network and the active power consumed by the AC electrical equipment within the substation; the power generation power of the distribution network and the power consumption power of the distribution network are balanced; the power generation power is the sum of the active power flowing through the substation converter in the distribution network, the photovoltaic power, and the wind power; the power consumption power is the sum of the active power consumed by the DC electrical equipment within the substation, the net power of the energy storage power station connected to the substation, and the transmission power of the interconnected line in the corresponding target interconnected substation of the substation.

[0084] Exemplarily, due to the dynamic variability of the operating characteristics of the distribution network, and due to the significant volatility of parameter information such as the obtained load magnitude and distributed new energy output, these fluctuations have an important impact on the stability of the system and the subsequent optimal dispatching process. Therefore, in order to more effectively cope with these uncertain factors and improve the dispatching robustness and stability of the system, the present embodiment also constructs the following: a wind speed - wind power uncertainty model, a light intensity - photovoltaic uncertainty model, and a load uncertainty model.

[0085] Specifically, in the wind speed - wind power uncertainty model, the wind speed, as a key factor affecting the output power of wind power, has strong randomness. Therefore, when modeling, we usually use the Weibull distribution to describe its uncertainty. The shape parameter k and the scale parameter c of the Weibull distribution are obtained by fitting the local climate data. Through these two parameters, the statistical characteristics of the wind speed in different regions can be accurately described, as specifically shown in the following formula (1 - 1):

[0086] (1 - 1)

[0087] Where, v represents the wind speed; k and c respectively represent the shape parameter and the scale parameter of the Weibull distribution; exp() represents the exponential function.

[0088] Among them, the wind speed is usually measured at a height of 10 meters above the ground, and there are differences in the hub height of the wind turbine impellers. Therefore, it is necessary to convert the wind speed measured on the ground to the wind speed at the working height h of the unit. This conversion process usually uses the logarithmic law of the wind speed for adjustment, as specifically shown in the following formula (1 - 2):

[0089] (1 - 2)

[0090] Where, v hThe wind speed at the hub height h of the impeller; v0 represents the wind speed at ground height; h0 represents the ground height; α v represents the ground roughness influence factor. Among them, the relationship between the power output of the wind farm and the wind speed can be referred to the following formula (1-3):

[0091] (1-3)

[0092] Among them, P wd represents the power output of the wind farm; represents the rated power of the wind farm; v rated 、v (cut-in) and v (cut-out) respectively represent the rated wind speed, cut-in wind speed and cut-out wind speed of the wind farm.

[0093] Specifically, in the light intensity - photovoltaic uncertainty model, light intensity is another important random uncertainty factor in photovoltaic power generation, and its change shows significant randomness. Therefore, the beta distribution (Beta Distribution) is often used to characterize the uncertainty of light intensity. The beta distribution is controlled by two parameters α and β, and is suitable for describing the fluctuation characteristics of light intensity within a specific range. Usually, the maximum value of light intensity is set to 1 to represent the peak value of light intensity. The beta distribution is specifically shown in the following formula (1-4):

[0094] (1-4)

[0095] Among them, I is the light intensity, I m is the maximum value of light intensity; α and β are the two parameters of the Beta distribution; Γ(g) is the gamma function. Among them, the relationship between the photovoltaic output power and the light intensity can be referred to the following formula (1-5):

[0096] (1-5)

[0097] Among them, P pv represents the output power of the photovoltaic; represents the rated power of the photovoltaic power station; I rated represents the rated light intensity.

[0098] Specifically, in the load uncertainty model, the uncertainty of the load is mainly reflected in the load fluctuation, and the normal distribution is usually used to describe it. The active power of the load can be regarded as a random variable, whose expected value is the average value of the load, and the standard deviation reflects the degree of load fluctuation. The normal distribution is specifically referred to the following formula (1-6):

[0099] (1-6)

[0100] Among them, P L , μ p and σ p respectively represent the stochastic quantity, expected value, and standard deviation of the active load.

[0101] It should be noted that in order to further quantitatively analyze the output of distributed new energy, energy storage power stations, etc., and the power distribution in the flexible interconnection system of the distribution substation area, the following constraints also need to be constructed in this embodiment: the linear power flow constraint of the distribution network, the "N-1" transfer constraint of the distribution substation area, the energy storage constraint, and the security constraint.

[0102] Specifically, for the linear power flow constraint of the distribution network, a linearized power flow model is used to represent the power flow and voltage distribution in the distribution network connected to the distribution substation area, which can refer to the following formulas (1-7):

[0103] (1-7)

[0104] Among them, f(j) and s(j) respectively represent the set of parent nodes and the set of child nodes of node j in the distribution network, and Ω n represents the set of slack nodes; P ij,t and Q ij,t respectively represent the active power and reactive power transmitted by the distribution network line ij at time t, and P jk,t and Q jk,t respectively represent the active power and reactive power transmitted by the distribution network line jk at time t; p j,t and q j,t respectively represent the active power and reactive power flowing out of node j in the distribution network at time t; U i,t represents the voltage amplitude of the medium-voltage distribution network node 𝑖 at time t; r ij and x ij respectively represent the resistance and reactance of the distribution network line ij.

[0105] Furthermore, for the sake of simplicity, the above model is transformed into the following formula (1-8):

[0106] (1-8)

[0107] Among them, P ij and Q ij respectively represent the active power and reactive power transmitted by the distribution network line ij; p i and q i respectively represent the active power and reactive power flowing out of node i in the distribution network; A is a constant matrix representing the topological situation of the parent and child nodes of the distribution network; D r and D x respectively represent the diagonal matrices of the resistance and reactance of the distribution network lines; U0 represents the voltage magnitude of the slack node.

[0108] Meanwhile, p i,t and q i,t satisfy the following power balance constraint as shown in the following formula (1-9):

[0109] (1-9)

[0110] where and respectively represent the active power and reactive power flowing through the converter of sub-region i at time t; and respectively represent the active power and reactive power of the AC load in sub-region i at time t, both of which are calculated through the load uncertainty model; represents the active power of the DC load in sub-region i at time t; and respectively represent the charging power and discharging power of the energy storage station connected to sub-region i at time t; represents the transmission power of the interconnection line between sub-region i and sub-region j at time t. If there is no interconnection between sub-region i and sub-region j, then . and respectively represent the output power and curtailment power of the photovoltaic power station connected to sub-region i at time t. The output power of the photovoltaic power station is calculated according to the light intensity-photovoltaic uncertainty model.

[0111] It should be noted that if sub-region i is not connected to a photovoltaic power station, then . Meanwhile, the curtailment power cannot be greater than the output power of the photovoltaic power station, that is: . where and respectively represent the output power and curtailment power of the wind power station connected to sub-region i at time t. The output power of the wind power station is calculated according to the wind speed-wind power uncertainty model. If sub-region i is not connected to a wind power station, then . Meanwhile, the curtailment power cannot be greater than the output power of the wind power station, that is: .

[0112] Specifically, in the "N-1" transfer constraint of the distribution substation area, the "N-1" event refers to the transformer or converter of a certain distribution substation area being taken out of service due to reasons such as faults. "N-1" transfer means that other normal substation areas flexibly interconnected with the faulty substation area can transfer power to the faulty substation area through the interconnection lines. To ensure the robustness of the model, it is set from the worst-case scenario, that is, when the "N-1" event occurs, the power of the energy storage power stations connected to all the substation areas within the substation area group where the faulty substation area is located is at the lower limit, the power outputs of the wind power stations and photovoltaic power stations are both 0, and the load size is at the upper limit. The DC power supply capacity during the normal operation of the distribution substation area is defined as the smaller value between the remaining capacity after the substation area transformer supplies the AC load and the rated capacity of the converter, as shown in the following formula (1-10):

[0113] (1-10)

[0114] Among them, represents the DC power supply capacity of substation area i; represents the rated capacity of the transformer of substation area i; φ is the power factor of the substation area transformer; is the maximum value of the AC load of substation area i; is the maximum active power that the converter of substation area i is allowed to transmit.

[0115] It should be noted that when the converter of the k-th substation area within a certain substation area group is taken out of service, the AC load of this substation area is all supplied by the transformer of this substation area, and the DC load is all DC transferred by the interconnected normal operation substation areas. Therefore, the sum of the DC power supply capacities of all the substation areas within this substation area group should not be less than the maximum value of the sum of the DC loads within this substation area group, that is . Among them, n represents the number of substation areas within the substation area group where the faulty substation area is located; represents the DC power supply capacity of the faulty substation area k, represents the maximum value of the DC load of substation area i.

[0116] It should be noted that when the transformer of the k-th substation area within the substation area group is taken out of service, the AC and DC loads of this substation area are all transferred by other interconnected substation areas. Therefore, the sum of the DC power supply capacities of all the substation areas within this substation area group should not be less than the sum of the maximum value of the AC load of the faulty substation area and the maximum values of the DC loads of all the substation areas, that is . Among them, represents the maximum value of the AC load of the faulty substation area k.

[0117] Specifically, in the energy storage power station constraint, the charge and discharge rate of the energy storage power station is related to the current operating state of the energy storage power station, as shown in the following formula (1-11):

[0118] (1-11)

[0119] Among them, and respectively represent the charging rate and discharging rate of the energy storage power station connected to the i-th substation area at time t; represents the operating state of the energy storage power station connected to the i-th substation area at time t, indicating that the energy storage power station is in the charging state, indicating that the energy storage power station is in the discharging state.

[0120] Meanwhile, in order to prevent the overcharge and overdischarge of the energy storage power station from affecting its lifespan, the electric energy of the power station should be maintained within the allowable range, that is, the following constraint shown in formula (1-12) should be satisfied:

[0121] (1-12)

[0122] Among them, represents the electric energy of the energy storage power station connected to the i-th substation area at time t; and respectively represent the upper and lower limits of the electric energy of the energy storage power station connected to the i-th substation area; η c and η d are the charging and discharging efficiencies of the energy storage power station respectively; τ represents the scheduling time interval; represents the size of the energy storage electric energy after scheduling.

[0123] S402. Determine the sum value between the photovoltaic power and the wind power as the received power of the substation area.

[0124] Specifically, determine the sum value between the photovoltaic power and the wind power; use this sum value as the received power of the substation area.

[0125] S403. Use the difference between the received power and the active power consumed by the DC electrical equipment in the substation area as the maximum net load of the substation area.

[0126] Specifically, determine the difference between the received power and the active power consumed by the DC electrical equipment in the substation area; use this difference as the maximum net load of the substation area.

[0127] In the above embodiment, it is possible to quantitatively analyze the output of distributed new energy, energy storage power stations, etc. and the power distribution in the flexible interconnection system of the distribution substation area to accurately determine the maximum net load of the substation area.

[0128] Figure 5 It is a flow chart of the steps for obtaining the load rate and power surplus / deficit value in an embodiment. This embodiment refines the steps for obtaining the load rate and power surplus / deficit value of each substation area in the above embodiment. This embodiment gives an optional way for the steps of obtaining the load rate and power surplus / deficit value, including the following steps:

[0129] S501. For each substation area, obtain the maximum net load, substation area power, and rated capacity of the transformer within the substation area.

[0130] Among them, the substation area power includes the active power and reactive power flowing out of the substation area from the distribution network, the net power of the energy storage power station connected to the substation area, and the transmission power of the interconnection line in the target interconnected substation area corresponding to the substation area.

[0131] S502. Take the power difference between the sum of powers and the charging power as the power surplus / deficit value of the substation area.

[0132] Among them, the sum of powers is the sum value between the maximum net load and the net power.

[0133] Specifically, through the following formula (1-13), take the power difference between the sum of powers and the charging power as the power surplus / deficit value of the substation area.

[0134] (1-13)

[0135] Among them, β i,t represents the load rate of node i at time t; β max represents the upper limit of the allowable load rate of the transformer; represents the rated capacity of the converter in substation area i; and respectively represent the upper and lower limits of the allowable transmission power of the interconnection line between substation area i and substation area j; x ij,t represents the soft-switching state of the interconnection line between substation area i and substation area j at time t, x ij,t =1 indicates that the soft switch is closed, x ij,t =0 indicates that the soft switch is open.

[0136] It should be noted that this embodiment should also simultaneously satisfy the constraint conditions: . Among them, and are respectively the upper and lower limits of the allowable voltage of distribution network node i at time t.

[0137] S503. Determine the load rate of the substation area according to the active power, reactive power, and rated capacity.

[0138] Specifically, through the following formula (1-14), determine the load rate of the substation area according to the active power, reactive power, and rated capacity.

[0139] (1-14)

[0140] Among them, represents the maximum net load of substation area i at time t, represents the magnitude of the power surplus / deficit of substation area i at time t.

[0141] It should be noted that this embodiment can also aim to minimize the total cost of the distribution system. The total cost includes the system operation cost, the operation cost of the flexible interconnection soft switch action, and the penalty cost. The objective function expression is shown in the following formula (1-15):

[0142] (1-15)

[0143] Among them, T represents the scheduling period; ψ N represents the set of distribution areas; the system operation cost includes the charge and discharge loss cost of the energy storage power station and the transmission power cost of the flexible interconnection line, and c b represents the unit operation cost of the charge and discharge power of the energy storage power station, and c loss represents the unit operation cost of the transmission power of the interconnection line; c switch represents the unit cost of one action of the flexible interconnection soft switch, and x ij,t and x ij,t-1 represent the state of the soft switch at the current moment and the state of the soft switch at the previous moment respectively; the penalty cost includes the load rate penalty cost, the power surplus and deficit penalty cost of the distribution area, and the wind and light abandonment penalty cost, and c β represents the unit penalty cost of the load rate, and c ub represents the unit penalty cost of the power surplus and deficit of the distribution area, and c e represents the unit penalty cost of wind and light abandonment.

[0144] In the above embodiment, the cross-distribution area consumption of distributed new energy and the load transfer of overloaded transformers can be realized through the power interaction between distribution areas, and the adaptability of the distribution area to the time series fluctuations of distributed new energy and load power can be improved.

[0145] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are sequentially shown according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least a part of other steps or steps in other steps.

[0146] Based on the same inventive concept, an embodiment of the present application further provides a distribution network substation area interconnection adjustment device for implementing the distribution network substation area interconnection adjustment method involved above. The implementation solutions provided by this device to solve problems are similar to those recorded in the above method. Therefore, the specific limitations in one or more embodiments of the distribution network substation area interconnection adjustment device provided below can refer to the limitations on the distribution network substation area interconnection adjustment method in the above text, and will not be repeated here.

[0147] In an exemplary embodiment, as Figure 6 shown, a distribution network substation area interconnection adjustment device is provided, including: an acquisition module 10, a selection module 20, a type module 30, and a disconnection module 40, where:

[0148] The acquisition module 10 is configured to acquire the load rate and power surplus / deficit value of each substation area in the distribution network; the distribution network includes at least one substation area cluster; the substation area cluster includes at least one group of interconnected substation areas; the interconnected substation areas only contain two substation areas, and the two substation areas are interconnected through a flexible connection switch.

[0149] The selection module 20 is configured to select the substation area with the highest load rate and determine the target substation area cluster to which the substation area with the highest load rate belongs.

[0150] The type module 30 is configured to determine the substation area type of each substation area in each group of target interconnected substation areas within the target substation area cluster according to the load rate and power surplus / deficit value of the substation area.

[0151] The disconnection module 40 is configured to disconnect the flexible connection switch when the substation area types of the two substation areas in the target interconnected substation areas are the same.

[0152] In some embodiments, the type module 30 is further configured to determine the load type of the substation area according to the magnitude relationship between the load rate of the substation area and a preset load rate threshold; and determine the power surplus / deficit type of the substation area according to the magnitude relationship between the power surplus / deficit value of the substation area and a preset surplus / deficit value threshold.

[0153] In some embodiments, the acquisition module 10 is further configured to, for each substation area, acquire the maximum net load, substation area power, and rated capacity of the transformer in the substation area; the substation area power includes the active power and reactive power flowing out of the substation area by the distribution network, the net power of the energy storage power station connected to the substation area, and the transmission power of the interconnected line in the target interconnected substation area corresponding to the substation area; use the power difference between the sum of powers and the charging power as the power surplus / deficit value of the substation area; the sum of powers is the sum of the maximum net load and the net power; and determine the load rate of the substation area according to the active power, reactive power, and rated capacity.

[0154] In some embodiments, the obtaining module 10 is further configured to obtain the photovoltaic power of the area accessing the photovoltaic power station, the wind power of the area accessing the wind power station, and the active power consumed by the DC electrical equipment in the area; determine the sum value between the photovoltaic power and the wind power as the received power of the area; and use the difference between the received power and the active power consumed by the DC electrical equipment in the area as the maximum net load of the area.

[0155] In some embodiments, the obtaining module 10 is further configured to obtain the rated power of the area accessing the wind power station, the wind speed parameters, and the current wind speed within the current time period; the wind speed parameters include the rated wind speed, the cut-in wind speed, and the cut-out wind speed of the wind power station; and determine the wind power of the area accessing the wind power station based on the magnitude relationship between the current wind speed and the wind speed parameters according to the rated power of the wind power station.

[0156] In some embodiments, the obtaining module 10 is further configured to obtain the active power flowing through the area converter of the distribution network, the active power consumed by the AC electrical equipment in the area, and the diagonal matrix of the distribution network; determine the active power flowing out of the distribution network from the area according to the diagonal matrix of the distribution network under the power balance constraint; wherein the power balance constraint includes at least one of the following: the active power flowing out of the distribution network from the area is balanced with the sum value between the active power flowing through the area converter of the distribution network and the active power consumed by the AC electrical equipment in the area; the power generation power of the distribution network and the power consumption power of the distribution network are balanced; the power generation power is the sum value between the active power flowing through the area converter of the distribution network, the photovoltaic power, and the wind power; the power consumption power is the sum value between the active power consumed by the DC electrical equipment in the area, the net power of the energy storage power station accessed by the area, and the transmission power of the interconnected line in the corresponding target interconnected area of the area.

[0157] Each module in the above distribution network area interconnection adjustment device can be implemented in whole or in part by software, hardware, and their combination. Each of the above modules can be embedded in the processor in the computer device in the form of hardware or be independent of the processor, or can be stored in the memory in the computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.

[0158] In an exemplary embodiment, a computer device is provided. The computer device can be a server, and its internal structure diagram can be as Figure 7As shown in the figure. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through a network connection. When the computer program is executed by the processor, it implements a method for interconnected adjustment of a distribution network substation area.

[0159] Those skilled in the art can understand that Figure 7 the structure shown in the figure is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0160] In an exemplary embodiment, a computer device is provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the steps in the above method embodiments are implemented.

[0161] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by the processor, the steps in the above method embodiments are implemented.

[0162] In one embodiment, a computer program product is provided, including a computer program. When the computer program is executed by the processor, the steps in the above method embodiments are implemented.

[0163] It should be noted that the data involved in this application (including but not limited to data for analysis, stored data, displayed data, etc.) are all information and data authorized by users or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0164] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in the present application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logic devices, data processing logics based on quantum computing, etc., without limitation.

[0165] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0166] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method for adjusting the interconnection of distribution network areas, characterized in that: The method comprises: Obtaining the load rate and power surplus / deficit value of each substation in the distribution network; the distribution network includes at least one substation cluster; the substation cluster includes at least one group of interconnected substations; the interconnected substations include only two substations, and the two substations are connected to each other through a flexible tie switch; Select the substation with the highest load rate, and determine the target substation cluster to which the substation with the highest load rate belongs; For each substation in each group of target interconnected substations in the target substation cluster, determine the substation type of the substation according to the load rate and power surplus or shortage value of the substation; When the area types of two areas in the target interconnected areas are consistent, the flexible tie switch is disconnected.

2. The method according to claim 1, characterized in that The substation type includes a load type and a power surplus or shortage type; and determining the substation type of the substation according to the load rate and the power surplus or shortage value of the substation includes: Determining the load type of the station area according to the magnitude relationship between the load rate of the station area and a preset load rate threshold; and, The power surplus / deficit type of the substation is determined according to the magnitude relationship between the power surplus / deficit value of the substation and a preset surplus / deficit value threshold.

3. The method according to claim 1, characterized in that The obtaining of the load rate and power surplus / deficit value of each substation in the distribution network includes: For each substation, obtain the maximum net load of the substation, the substation power and the rated capacity of the transformer in the substation; the substation power includes the active power and reactive power flowing out of the distribution network from the substation, the net power of the energy storage power station connected to the substation, and the transmission power of the interconnection line in the target interconnected substation corresponding to the substation; The power difference between the power sum value and the charging power is used as the power surplus or shortage value of the station area; the power sum value is the sum of the maximum net load and the net power; and, The load factor of the substation is determined according to the active power, the reactive power and the rated capacity.

4. The method according to claim 3, characterized in that Obtain the maximum net load of the station area, including: Obtaining the photovoltaic power of the photovoltaic power station connected to the substation, the wind power of the wind power station connected to the substation, and the active power consumed by the DC power equipment in the substation; Determine the sum of the photovoltaic power and the wind power as the received power of the station area; The difference between the received power and the active power consumed by the DC power-consuming equipment in the substation is taken as the maximum net load of the substation.

5. The method according to claim 4, characterized in that A method for obtaining wind power connected to a wind power station includes: Obtaining the rated power, wind speed parameters and current wind speed in the current period of the wind power station connected to the substation; the wind speed parameters include the rated wind speed, cut-in wind speed and cut-out wind speed of the wind power station; Based on the magnitude relationship between the current wind speed and the wind speed parameter and according to the rated power of the wind power station, the wind power connected to the wind power station is determined.

6. The method according to claim 4, characterized in that Obtaining the active power of the distribution network flowing out of the substation area, including: Obtaining the active power of the distribution network flowing through the converter in the substation area, the active power consumed by the AC power equipment in the substation area, and the diagonal matrix of the distribution network; According to the diagonal matrix of the distribution network, under the power balance constraint, determining the active power of the distribution network flowing out of the substation; Among them, the power balance constraint includes at least one of the following: the active power flowing out of the distribution network from the substation is balanced with the sum of the active power of the distribution network flowing through the substation converter and the active power consumed by the AC power equipment in the substation; the power generation power of the distribution network and the power consumption of the distribution network are balanced; the power generation power is the sum of the active power of the distribution network flowing through the substation converter, photovoltaic power and wind power; the power consumption power is the sum of the active power consumed by the DC power equipment in the substation, the net power of the energy storage power station connected to the substation and the transmission power of the interconnection lines in the target interconnected substation corresponding to the substation.

7. A distribution network area interconnection adjustment device, characterized in that: The device comprises: An acquisition module is used to acquire the load rate and power surplus / deficit value of each substation in the distribution network; the distribution network includes at least one substation cluster; the substation cluster includes at least one group of interconnected substations; the interconnected substations include only two substations, and the two substations are connected to each other through a flexible tie switch; A selection module is used to select the substation with the highest load rate and determine the target substation cluster to which the substation with the highest load rate belongs; A type module, for determining the type of each substation in each group of target interconnected substations in the target substation cluster according to the load rate and power surplus or shortage value of the substation; The disconnection module is used to disconnect the flexible tie switch when the area types of two areas in the target interconnected area are consistent.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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