Source network load storage layering and partitioning balance model based on grid

Abstract

The invention belongs to the technical field of power distribution system planning, and particularly relates to a grid-based source network load storage layering and partitioning balance model. Comprising the following steps: S1, dividing a power distribution system into three levels, namely a power utilization grid, a power supply unit and a power supply grid; s2, determining partition boundary internet access interface parameters of the power utilization grid and a related power flow constraint equation; s3, determining partition boundary internet access interface parameters of the power supply unit and a related power flow constraint equation; s4, determining partition boundary internet access interface parameters of the power supply grid and a related power flow constraint equation; the method can effectively control the maximum load level needing power supply of the power transmission system, distinguishes the difference of the conventional load and the controllable load on the power supply reliability requirements, adopts an effective control means, reduces the maximum load demand of the system, improves the load characteristics of the system, and plays an important role in improving the utilization rate of power grid asset equipment and the asset investment benefit. And planning and realization of integration of the source, the network, the load and the storage in the power distribution system can be effectively promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of power distribution system planning, and in particular relates to a grid-based source-grid-load-storage layered and zoned balance model. Background Art

[0002] By the end of 2019, the total installed capacity of wind and solar power generation in China reached 414 million kW, accounting for 20.59% of the total installed capacity, and showed a further growth trend. In terms of power generation characteristics, the average full-output power generation hours of wind power generation and photovoltaic power generation in China in 2019 were 2082h and 1285h, respectively, accounting for 23.7% and 14.7% of the total annual hours, respectively.

[0003] The large changes in the output of intermittent generators and the extremely long duration of low output have put forward new requirements for the energy storage capacity in the distribution system to fully accommodate the requirements of wind and solar power generation output. Therefore, under the background of the continuous growth of the installed capacity of intermittent generators, the operation of the power system needs to deal with two problems: First, the high output of wind and solar power generation will lead to large-capacity power transmission or require more energy storage capacity; second, in the face of climate change that is difficult to accurately predict, the uncertainty of wind and solar power generation output brings difficulties and even challenges to the power system's power generation planning, real-time dispatching and safe operation, and leads to problems such as increased difficulty and cost of power system security and low system operation efficiency. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a grid-based source-grid-load-storage hierarchical and partitioned balancing model. In the local power grid, the traditional power balancing mode in which the source follows the load will be transformed into a partitioned on-site balancing mode in which the load follows the source and is centered on the regional distribution system or microgrid, so as to improve the new energy absorption capacity and ensure the stable operation of the power grid.

[0005] The object of the present invention is achieved by: a grid-based source-grid-load-storage stratified partition balance model, include Follow these steps:

[0006] S1. Divide the power distribution system into three levels: power grid, power supply unit, and power supply grid;

[0007] S2. Determine the grid boundary parameters and related power flow constraint equations of the power grid;

[0008] S3, determine the partition boundary access interface parameters of the power supply unit and related power flow constraint equations;

[0009] S4. Determine the grid-connected interface parameters and related power flow constraint equations at the partition boundaries of the power grid.

[0010] Furthermore, the step S2 determines the partition boundary access interface parameters of the power grid and the related power flow constraint equations, including:

[0011] The electricity grid is a management unit for forecasting diversified electricity demand.

[0012] ①Internet access boundary interface

[0013]

[0014] Where: P i P , P i B , P i G are the boundary interface values ​​of the maximum grid supply load, grid purchase reserve capacity, and maximum grid output demand of the power grid i, respectively; are the control values ​​or predicted values ​​of the maximum load of the power grid i, the backup capacity of the power grid, and the maximum power demand of the power grid i;

[0015] ②Node constraint equation, 400V busbar in the distribution room

[0016] When planning the low-voltage distribution system, the distributed power access scheme determined should be able to ensure the local consumption of intermittent renewable energy generation, and the power flow on the 10 kV switch side of the distribution transformer will not be reversed; when P i G When it is greater than 0, 10 kV access method is adopted.

[0017] The conventional load, controllable load, distributed generation and energy storage on the 400 V bus segment are balanced and optimized to meet the requirements of local consumption of intermittent renewable energy generation and non-reverse transmission of distribution transformer power flow. When the 400 V bus cannot achieve local consumption of intermittent renewable energy generation, the access voltage level of the distributed generation should be increased.

[0018] Furthermore, the step S3 determines the partition boundary Internet access interface parameters of the power supply unit and the related power flow constraint equations including:

[0019] The power supply unit is a management unit for optimizing the medium voltage grid structure.

[0020] ①Internet access boundary interface

[0021]

[0022] Where: n j is the number of power grids included in power supply unit j; are the boundary interface values ​​of the maximum load of the grid supply, the grid purchase reserve capacity, and the maximum output demand of the grid i in the power supply unit j, respectively;

[0023] ②Node constraint equation, 10kV incoming and outgoing lines

[0024] Feeder line outgoing line

[0025]

[0026] Power line incoming

[0027]

[0028] Where: n l is the number of power grids included in the 10kV line l; are the boundary interface values ​​of the maximum load, backup capacity and maximum output demand of the power grid i in line l; l max It is the maximum power supply capacity limit value of 10kV line l.

[0029] Optimize and determine the access mode of distributed power generation at the 10kV voltage level, including two types: power dedicated line (including branch line) and general load line (only branch line). Optimize and determine the segmented position of the distributed power generation at the 10kV voltage level to access the load line to achieve segmented balance of power supply and load.

[0030] Furthermore, the step S4 determines the partition boundary access interface parameters of the power grid and the related power flow constraint equations, including:

[0031] The power grid is the management unit where the lines access the substation busbars.

[0032] ①Internet access boundary interface

[0033]

[0034] Where: m k is the number of power supply units included in the power supply grid k; are the boundary interface values ​​of the maximum grid supply load, grid purchase reserve capacity, and maximum grid output demand of power supply unit j in power supply grid k, respectively;

[0035] ②Node constraint equation, substation 10kV bus

[0036] The designed distributed power access scheme should ensure that intermittent renewable energy generation can be locally consumed and the switch power flow on the 10kV side of the main transformer is not reversed; When it is greater than 0 and the surrounding power grid cannot absorb intermittent renewable energy generation, a high-voltage access method of 35kV or above should be used;

[0037] Optimize the location where the 10kV feeder line is connected to the substation bus segment; optimize the location where the 10kV distributed power source dedicated line is connected to the bus segment to achieve the balance and optimization of power supply and load on the bus segment; when the 10kV bus cannot achieve local consumption of intermittent renewable energy generation, the access voltage level of the distributed power source should be increased;

[0038] The participants in the balancing unit are diverse, including distributed power sources, conventional loads, flexible loads (user-side demand response), energy storage (including electric vehicles), etc. The balancing equation of the i-th power supply unit is as follows:

[0039]

[0040] Where P i N represents the grid load of the ith power supply unit; P i load represents the conventional load power consumption of the ith power supply unit; P i DG represents the output power of the distributed power supply of the i-th power supply unit; P i ES represents the energy storage charging and discharging power of the i-th power supply unit; P i DR represents the flexible load power consumption of the i-th power supply unit; P i EX represents the interaction power between the i-th power supply unit and other units;

[0041] The balance equation of the jth power grid is as follows:

[0042]

[0043] In the formula, K t represents the simultaneous rate; n j represents the number of power supply units contained in the jth power supply grid; represents the grid load of the jth power supply grid; represents the interaction power between the jth power grid and other grids;

[0044] The balance equation for the kth power supply partition is as follows:

[0045]

[0046] In the formula, m k represents the number of power supply grids in the kth power supply partition; represents the grid supply load of the kth power supply partition; It represents the interaction power between the kth power supply partition and other partitions.

[0047] Beneficial effects of the present invention: A grid-based source-grid-load-storage hierarchical and zoned balance model of the present invention analyzes transmission buses of various voltage levels such as 400V, 10kV, and 35kV at the levels of power grids, power supply units, and power supply units, establishes corresponding node constraint equations, calculates whether the local consumption of intermittent renewable energy generation and the non-reverse transmission requirements of distribution transformer currents can be met, and provides how to increase the access voltage level or other means to meet the relevant requirements if the goals cannot be achieved. It is achieved that each unit at each level can operate independently or be interconnected through interconnection lines. While giving priority to achieving real-time net power self-balancing of source, load, and storage within and between zones, if there is a shortage, it can still rely on the upper power grid for power supply. Local consumption of intermittent renewable energy generation is achieved, and stable operation of the power system is maintained. By constructing a hierarchical and zoned balance model, energy storage is reasonably configured, the power grid structure is optimized, and the power grid's acceptance capacity for distributed power sources is improved, the safe, stable, and efficient operation of the power system is achieved. The present invention can effectively solve the problem of planning and designing intelligent distribution systems taking into account distributed resources and their coordination, so that the entire community can share the benefits brought by load control, high-efficiency energy saving, distributed power generation and energy storage; the present invention can effectively control the maximum load level that needs to be supplied by the transmission system, distinguish the differences in power supply reliability requirements between conventional loads and controllable loads, take effective control measures, reduce the system's maximum load demand, and improve the system's load characteristics, which plays an important role in improving the utilization rate of power grid assets and equipment and the investment benefits of assets; the present invention can realize the autonomous self-healing management of the distribution system according to the grid, deepen the grid management of the distribution system, and enhance the autonomous self-healing ability of the grid, thereby reducing the difficulty from planning and design to dispatching and operation of the distribution system, and can effectively promote the planning and implementation of "source-grid-load-storage integration" in the distribution system. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0049] Figure 1 It is a grid-based source-grid-load-storage stratified partition balance model;

[0050] Figure 2 This is the power balancing unit model. DETAILED DESCRIPTION

[0051] The present invention will be further described below in conjunction with the accompanying drawings.

[0052] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] A grid-based source-grid-load-storage stratified partition balance model of the present invention comprises the following steps:

[0055] S1. Divide the power distribution system into three levels: power grid, power supply unit, and power supply grid;

[0056] S2. Determine the grid boundary parameters and related power flow constraint equations of the power grid;

[0057] S3, determine the partition boundary access interface parameters of the power supply unit and related power flow constraint equations;

[0058] S4. Determine the grid-connected interface parameters and related power flow constraint equations at the partition boundaries of the power grid.

[0059] The grid-based "source, grid, load, and storage" hierarchical and partitioned balancing technology route aims to optimize the planning and operation of modern distribution systems. This technology route first divides the distribution system into multiple levels such as power grid, power supply unit, and power supply grid through a grid model to achieve hierarchical and partitioned balance of "source, grid, load, and storage". On this basis, the flexible adjustment capabilities of energy storage systems and distributed power sources are used to meet diversified power demand and improve the power supply reliability and asset utilization efficiency of the power grid. By accurately predicting and controlling the balance of power supply and demand at all levels, effective absorption of intermittent renewable energy generation can be achieved. At the same time, with the help of the electricity price incentive mechanism in power market transactions, resource allocation is optimized, the maximum load demand of the system is reduced, and load characteristics are improved. Ultimately, this technology route will promote the development of distribution systems in a more intelligent and adaptive direction, improve the overall operating efficiency and safety of the power system, and provide strong support for energy transformation and sustainable development.

[0060] According to the relevant technical regulations on the access of distributed power sources to the distribution system, the distribution system is divided into three levels: power consumption grid, power supply unit and power supply grid, and the boundary interface values ​​and constraints of each level are determined.

[0061] Considering the radial operation characteristics and protection configuration principles of the distribution system, in the planning stage, the control nodes of the unidirectional power flow (anti-backflow) of the distribution system are set as the low-voltage side switch of the substation transformer, the inlet and outlet switches of the low-voltage busbar of the substation, and the high-voltage side switch of the distribution transformer. On this basis, according to the grid level definition of the distribution system, it can be obtained Figure 1 The grid-based “source-grid-load-storage” hierarchical and partitioned balance model is shown.

[0062] exist Figure 1 In the balancing of "source, grid, load and storage", there are three grid levels: power grid, power supply unit and power supply grid. Among them, the 10kV side switch of the main transformer of the substation, the 10kV feeder outgoing line switch and the 10kV side switch of the distribution transformer are the three nodes of the system flow control, which need to meet the two safety constraints of the system operation: the maximum power supply capacity of the line and the one-way flow of the switch (anti-backflow). The following introduces the calculation method of the partition boundary access interface parameters of these three levels of grids and the related flow constraint equations.

[0063] Furthermore, the step S2 determines the partition boundary access interface parameters of the power grid and the related power flow constraint equations, including:

[0064] The electricity grid is a management unit for forecasting diversified electricity demand.

[0065] ①Internet access boundary interface

[0066]

[0067] Where: P i P , P i B , P i G are the boundary interface values ​​of the maximum grid supply load, grid purchase reserve capacity, and maximum grid output demand of the power grid i, respectively; They are respectively the control values ​​or predicted values ​​of the maximum grid load, grid purchase reserve capacity, and maximum grid output demand of power grid i; since the power grid is the smallest prediction unit for diversified power demand, its boundary interface value is equal to its corresponding control value or predicted value.

[0068] ②Node constraint equation, 400V busbar in the distribution room

[0069] When planning the low-voltage distribution system, the distributed power access scheme determined should be able to ensure the local consumption of intermittent renewable energy generation, and the power flow on the 10kV switch side of the distribution transformer will not be reversed; when P i G When it is greater than 0, 10kV access method is adopted.

[0070] The conventional load, controllable load, distributed power source and energy storage on the 400V bus segment are balanced and optimized to meet the requirements of local consumption of intermittent renewable energy generation and non-reverse transmission of distribution transformer power flow. When the 400V bus cannot achieve local consumption of intermittent renewable energy generation, the access voltage level of the distributed power source should be increased.

[0071] Furthermore, the step S3 determines the partition boundary Internet access interface parameters of the power supply unit and the related power flow constraint equations including:

[0072] The power supply unit is a management unit for optimizing the medium voltage grid structure.

[0073] ①Internet access boundary interface

[0074]

[0075] Where: n j is the number of power grids included in power supply unit j; are the boundary interface values ​​of the maximum load of the grid supply, the grid purchase reserve capacity, and the maximum output demand of the grid i in the power supply unit j, respectively;

[0076] From equations (4)-(6), it can be seen that the boundary interface value of the power supply unit is equal to the sum of the corresponding values ​​of the power grid it contains. When it is greater than 0, the current power supply unit cannot realize the local consumption of intermittent renewable energy generation, and should be connected to the 10kV busbar of the substation through a 10kV power line;

[0077] ②Node constraint equation, 10kV incoming and outgoing lines

[0078] Feeder line outgoing line

[0079]

[0080] Power line incoming

[0081]

[0082] Where: n l is the number of power grids included in the 10kV line l; are the boundary interface values ​​of the maximum load, backup capacity and maximum output demand of the power grid i in line l; l max It is the maximum power supply capacity limit value of 10kV line l.

[0083] From equations (7)-(8), it can be seen that the maximum load of feeder line l is equal to the sum of the maximum load of the power grid it contains and the reserve capacity of the network purchase, which should be less than the maximum power supply capacity of the line; the maximum online output should be less than or equal to 0 to meet the unidirectional power flow constraint of the feeder. From equation (9), it can be seen that the maximum online output demand of power line l is equal to the sum of the maximum online output of the power grid it contains, which should be less than the maximum transmission capacity of the line, and the value should be less than or equal to 0.

[0084] Optimize and determine the access mode of distributed power generation at the 10kV voltage level, including two types: power dedicated line (including branch line) and general load line (only branch line). Optimize and determine the segmented position of the distributed power generation at the 10kV voltage level to access the load line to achieve segmented balance of power supply and load.

[0085] Furthermore, the step S4 determines the partition boundary access interface parameters of the power grid and the related power flow constraint equations, including:

[0086] The power grid is the management unit where the lines access the substation busbars.

[0087] ①Internet access boundary interface

[0088]

[0089] Where: m k is the number of power supply units included in the power supply grid k; are the boundary interface values ​​of the maximum grid supply load, grid purchase reserve capacity, and maximum grid output demand of power supply unit j in power supply grid k, respectively;

[0090] From equations (10)-(12), it can be seen that the boundary interface value of the power grid is equal to the sum of the corresponding values ​​of the power supply units it contains; when When it is greater than 0, the current power supply grid cannot realize the local consumption of intermittent renewable energy generation, and should be connected to the high-voltage side bus of the substation through a 35kV or above power line.

[0091] ②Node constraint equation, substation 10kV bus

[0092] The designed distributed power access scheme should ensure that intermittent renewable energy generation can be locally consumed and the switch power flow on the 10kV side of the main transformer is not reversed; When it is greater than 0 and the surrounding power grid cannot absorb intermittent renewable energy generation, a high-voltage access method of 35kV or above should be used;

[0093] Optimize the location where the 10kV feeder line is connected to the substation bus segment; optimize the location where the 10kV distributed power source dedicated line is connected to the bus segment to achieve the balance and optimization of power supply and load on the bus segment; when the 10kV bus cannot achieve local consumption of intermittent renewable energy generation, the access voltage level of the distributed power source should be increased;

[0094] Each unit in the above-mentioned levels is independent of each other, but can also be interconnected through interconnection lines. Each level gives priority to achieving real-time net power self-balancing of source, load and storage within and between zones, and the insufficient part relies on the upper power grid for power supply. The power supply unit balancing model is as follows: Figure 2 As shown;

[0095] The participants in the balancing unit are diverse, including distributed power sources, conventional loads, flexible loads (user-side demand response), energy storage (including electric vehicles), etc. The balancing equation of the i-th power supply unit is as follows:

[0096] P i N =P i load -P i DR -P i ES -P i DG -P i EX (13)

[0097] Where P i N represents the grid load of the ith power supply unit; P i load represents the conventional load power consumption of the ith power supply unit; P i DG represents the output power of the distributed power supply of the i-th power supply unit; P i ES represents the energy storage charging and discharging power of the i-th power supply unit; P i DR represents the flexible load power consumption of the i-th power supply unit; P i EX represents the interaction power between the i-th power supply unit and other units;

[0098] The balance equation of the jth power grid is as follows:

[0099]

[0100] In the formula, K t represents the simultaneous rate; n j represents the number of power supply units contained in the jth power supply grid; represents the grid load of the jth power supply grid; represents the interaction power between the jth power grid and other grids;

[0101] The balance equation for the kth power supply partition is as follows:

[0102]

[0103] In the formula, m k represents the number of power supply grids in the kth power supply partition; represents the grid supply load of the kth power supply partition; It represents the interaction power between the kth power supply partition and other partitions.

[0104] In summary, the grid-based source-grid-load-storage hierarchical and zoned balance model of the present invention analyzes transmission buses of various voltage levels such as 400V, 10kV, and 35kV at the levels of power grid, power supply unit, and power supply unit, establishes corresponding node constraint equations, calculates whether the local consumption of intermittent renewable energy generation and the non-reverse transmission requirements of distribution transformer flow can be met, and provides how to increase the access voltage level or other means to meet the relevant requirements if the goal cannot be achieved. It is achieved that each unit at each level can operate independently or be interconnected through interconnection lines. While giving priority to achieving real-time net power self-balancing of source, load, and storage within and between zones, if there is a shortage, it can still rely on the upper power grid for power supply. Local consumption of intermittent renewable energy generation is achieved, and stable operation of the power system is maintained. By constructing a hierarchical and zoned balance model, energy storage is reasonably configured, the power grid structure is optimized, and the power grid's acceptance capacity for distributed power sources is improved, the safe, stable, and efficient operation of the power system is achieved. The present invention can effectively solve the problem of planning and designing intelligent distribution systems taking into account distributed resources and their coordination, so that the entire community can share the benefits brought by load control, high-efficiency energy saving, distributed power generation and energy storage; the present invention can effectively control the maximum load level that needs to be supplied by the transmission system, distinguish the differences in power supply reliability requirements between conventional loads and controllable loads, take effective control measures, reduce the system's maximum load demand, and improve the system's load characteristics, which plays an important role in improving the utilization rate of power grid assets and equipment and the investment benefits of assets; the present invention can realize the autonomous self-healing management of the distribution system according to the grid, deepen the grid management of the distribution system, and enhance the autonomous self-healing ability of the grid, thereby reducing the difficulty from planning and design to dispatching and operation of the distribution system, and can effectively promote the planning and implementation of "source-grid-load-storage integration" in the distribution system.

[0105] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", 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 invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0106] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A grid-based source-grid-load-storage stratified partition balance model, characterized in that: The following steps are involved: S1. Divide the power distribution system into three levels: power grid, power supply unit, and power supply grid; S2. Determine the grid boundary parameters and related power flow constraint equations of the power grid; S3, determine the partition boundary access interface parameters of the power supply unit and related power flow constraint equations; S4. Determine the grid-connected interface parameters and related power flow constraint equations at the partition boundaries of the power grid.

2. A grid-based source-grid-load-storage stratified partition balance model as claimed in claim 1, characterized in that: The step S2 of determining the partition boundary access interface parameters of the power grid and the related power flow constraint equations includes: ①Internet access boundary interface Where: P i P , P i B , P i G are the boundary interface values ​​of the maximum grid supply load, grid purchase reserve capacity, and maximum grid output demand of the power grid i, respectively; are the control values ​​or predicted values ​​of the maximum load of the power grid i, the backup capacity purchased by the grid, and the maximum output demand of the grid i; ②Node constraint equation, 400V busbar in the distribution room When planning the low-voltage distribution system, the distributed power access scheme determined should be able to ensure the local consumption of intermittent renewable energy generation, and the power flow on the 10kV switch side of the distribution transformer will not be reversed; when P i G When it is greater than 0, 10kV access method is adopted.

3. A grid-based source-grid-load-storage stratified partition balance model as claimed in claim 1, characterized in that: The step S3 determines the partition boundary access interface parameters of the power supply unit and the related power flow constraint equations, including: ①Internet access boundary interface Where: n j is the number of power grids included in power supply unit j; are the boundary interface values ​​of the maximum load of the grid supply, the grid purchase reserve capacity, and the maximum output demand of the grid i in the power supply unit j, respectively; ②Node constraint equation, 10kV incoming and outgoing lines Feeder line outgoing line Power line incoming Where: n l is the number of power grids included in the 10kV line l; are the boundary interface values ​​of the maximum load, backup capacity and maximum output demand of the power grid i in line l; l max It is the maximum power supply capacity limit value of 10kV line l.

4. A grid-based source-grid-load-storage stratified partition balance model as claimed in claim 1, characterized in that: The step S4 determines the partition boundary access interface parameters of the power grid and the related power flow constraint equations, including: The power grid is the management unit where the lines access the substation busbars. ①Internet access boundary interface Where: m k is the number of power supply units included in the power supply grid k; are the boundary interface values ​​of the maximum grid supply load, grid purchase reserve capacity, and maximum grid output demand of power supply unit j in power supply grid k, respectively; ②Node constraint equation, substation 10kV bus The designed distributed power access scheme should ensure that intermittent renewable energy generation can be locally consumed and that the switch power flow on the 10kV side of the main transformer is not reversed; When it is greater than 0 and the surrounding power grid cannot absorb intermittent renewable energy generation, a high-voltage access method of 35kV or above should be used; Optimize the location where the 10kV feeder line is connected to the substation bus segment; optimize the location where the 10kV distributed power source dedicated line is connected to the bus segment to achieve the balance and optimization of power supply and load on the bus segment; when the 10kV bus cannot achieve local consumption of intermittent renewable energy generation, the access voltage level of the distributed power source should be increased; The participants in the balancing unit are diverse, including distributed power sources, conventional loads, flexible loads, energy storage, etc. The balancing equation of the i-th power supply unit is as follows: P i N =P i load -P i DR -P i ES -P i DG -P i EX (13) Where P i N represents the grid load of the ith power supply unit; P i load represents the conventional load power consumption of the ith power supply unit; P i DG represents the output power of the distributed power supply of the i-th power supply unit; P i ES represents the energy storage charging and discharging power of the i-th power supply unit; P i DR represents the power consumption of the flexible load of the ith power supply unit; P i EX represents the interaction power between the i-th power supply unit and other units; The balance equation of the jth power grid is as follows: In the formula, K t represents the simultaneous rate; n j represents the number of power supply units contained in the jth power supply grid; represents the grid load of the jth power supply grid; represents the interaction power between the jth power grid and other grids; The balance equation for the kth power supply partition is as follows: In the formula, m k represents the number of power supply grids in the kth power supply partition; represents the grid supply load of the kth power supply partition; It represents the interaction power between the kth power supply partition and other partitions.

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