Micro-grid group user energy storage demand quantitative analysis method and system

Abstract

The invention discloses a micro-grid group user energy storage demand quantitative analysis method and system, and belongs to the technical field of power system user side energy storage planning and demand analysis. The problem that an existing micro-grid group user energy storage demand analysis method does not give consideration to multi-target and multi-operation-mode quantitative analysis is solved. The method comprises the steps of obtaining a typical daily net load curve of each microgrid in a microgrid group, calculating a difference value between a load at each moment and new energy output, and identifying a new energy consumption pressure interval and a reliable power supply pressure interval; overlapping the net load curve, and determining an energy storage complementary window; energy storage demand analysis models in an independent mode and a sharing mode are respectively constructed by taking optimization of economical efficiency, environmental protection performance and power supply reliability as targets, and energy storage capacity and power demand values are obtained through quantification; comparing the demand critical values under different target combinations to obtain a first energy storage comprehensive demand value of the micro-grid user and a second energy storage comprehensive demand value of the micro-grid group user; the method is applied to the micro-grid.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system user side energy storage planning and demand analysis, and in particular to a micro-grid group user energy storage demand quantitative analysis method and system. BACKGROUND

[0002] With the continuous advancement of new power system construction, microgrids containing distributed photovoltaics are widely deployed in industrial parks, park-level distribution networks and other scenarios. Multiple adjacent microgrids are often interconnected through the upper distribution network or dedicated lines to form a "micro-grid group". Under this background, micro-grid group users face a series of problems such as whether to configure energy storage, how to determine the capacity of energy storage, and which investment and operation mode to choose. Currently, there is still a lack of directly quantifiable decision-making basis, which restricts the scientific planning and efficient use of micro-grid group energy storage systems.

[0003] Around the flexible power demand of micro-grid groups, user energy storage configuration presents multi-objective characteristics: it is expected to reduce electricity purchase cost and capacity cost through peak-valley electricity price arbitrage, it is also expected to reduce carbon emissions by improving local new energy consumption rate, and it is required to ensure the power supply reliability of important loads during power grid failure or island operation. Therefore, how to coordinate the economic, environmental and reliability targets to form a quantitative analysis method that can directly output the energy storage power and capacity demand boundary has become a key problem that needs to be solved in micro-grid group engineering practice.

[0004] Currently, research in the field of energy storage planning and operation is mostly focused on the system side, mainly focusing on the selection and capacity determination of energy storage in a single micro-grid or distribution network, the optimal configuration of capacity, and the economic evaluation of the whole life cycle. For example, by establishing an optimization model with the goal of peak clipping, valley filling, reducing abandoned light and wind cost, or improving power supply reliability, the energy storage configuration scheme is determined; or based on the comparison of different energy storage technology economic characteristics, reference is provided for type selection. These studies have certain guiding significance, but are mostly still limited to a single system category and fail to fully reflect the characteristics of multi-microgrid coordinated operation and complementary source and load characteristics in micro-grid groups. There is also a lack of systematic methods for deducing energy storage capacity from actual user demand.

[0005] With the development of microgrids into groups, some research has begun to focus on issues such as multi-microgrid coordinated operation and shared energy storage operation mode, such as analyzing the revenue differences of energy storage projects under different business models, or exploring micro-grid group optimization operation strategies mainly to promote new energy consumption. However, existing work focuses more on "how to utilize existing energy storage to improve system efficiency", and lacks research on "how much energy storage is needed on the user side" and "demand differences under different investment modes", and has not yet formed a quantitative energy storage demand analysis method that takes into account multi-dimensional targets and covers both independent and shared operation modes. SUMMARY

[0006] The present application aims at solving the technical problems that the existing micro-grid group user energy storage demand analysis method does not consider multi-dimensional targets and does not cover independent and shared operation modes to quantitatively analyze energy storage demand, thereby restricting the scientific planning and efficient utilization of micro-grid group energy storage systems.

[0007] To solve the above technical problems, the technical scheme adopted by the present application is as follows: a micro-grid group user energy storage demand quantitative analysis method, comprising the following steps:

[0008] Step S1, obtaining multiple typical days representing different operating characteristics of each micro-grid in the micro-grid group;

[0009] Step S2, obtaining the net load power curve of each micro-grid in each typical day, and based on the net load power curve, obtaining the difference between the load demand and new energy output of each micro-grid at each time;

[0010] Step S3, identifying the new energy consumption pressure interval and reliable power supply pressure interval of the micro-grid based on the difference between the load demand and new energy output at each time;

[0011] Step S4, superimposing the net load power curves of each micro-grid in each typical day to analyze the time misalignment characteristics of the new energy consumption pressure and reliable power supply pressure between each pair of micro-grids, and identifying the energy storage complementary window interval that can be shared by the micro-grid group users;

[0012] Step S5, based on the new energy consumption pressure interval, the reliable power supply pressure interval, and the energy storage complementary window interval that can be shared by the micro-grid group users, constructing a micro-grid user energy storage demand quantitative analysis model and a micro-grid group user energy storage demand quantitative analysis model with economic optimization, environmental optimization, and power supply reliability optimization as the three core targets, thereby obtaining the demand energy storage capacity and demand energy storage power value of the micro-grid user and the micro-grid group user under the corresponding target;

[0013] Step S6, comparing and analyzing the critical value of the first demand energy storage capacity and the critical value of the first demand energy storage power value obtained by the micro-grid user under different target combinations to obtain the first energy storage comprehensive demand value of the micro-grid user under the corresponding target combination; comparing and analyzing the critical value of the second demand energy storage capacity and the critical value of the second demand energy storage power value obtained by the micro-grid group user under the economic optimization and environmental optimization target combination to obtain the second energy storage comprehensive demand value of the micro-grid group user under the economic optimization and environmental optimization target combination.

[0014] Further, the micro-grid user energy storage demand quantitative analysis model comprises a micro-grid user energy storage capacity demand quantitative analysis model and a micro-grid user power demand quantitative analysis model;

[0015] The micro-grid group user energy storage demand quantitative analysis model comprises a micro-grid group user energy storage capacity demand quantitative analysis model and a micro-grid group user power demand quantitative analysis model.

[0016] Further, in the step S5, the process of constructing the micro-grid user energy storage demand quantitative analysis model and the micro-grid group user energy storage demand quantitative analysis model with the economic optimization as the core target is as follows:

[0017] Based on the peak-valley arbitrage profit maximization constraint relationship of the single micro-grid and the micro-grid group, combined with the analysis results of the upper limit of the charging power in the valley period and the upper limit of the discharging power in the peak period, the micro-grid user energy storage demand quantitative analysis model with the economic optimization as the target and the micro-grid group user energy storage demand quantitative analysis model with the economic optimization as the target are constructed respectively, and the micro-grid user demand energy storage capacity and demand energy storage power value with the economic optimization as the target and the micro-grid group user demand energy storage capacity and demand energy storage power value with the economic optimization as the target are obtained.

[0018] Further, in the step S5, the process of constructing the micro-grid user energy storage demand quantitative analysis model and the micro-grid group user energy storage demand quantitative analysis model with the environmental protection optimization as the core target is as follows:

[0019] Based on the constraint relationship between the local consumption rate of new energy and the demand energy storage capacity, the micro-grid user energy storage demand quantitative analysis model with the environmental protection optimization as the target and the micro-grid group user energy storage demand quantitative analysis model with the environmental protection optimization as the target are constructed respectively, and the micro-grid user demand energy storage capacity and demand energy storage power value with the environmental protection optimization as the target and the micro-grid group user demand energy storage capacity and demand energy storage power value with the environmental protection optimization as the target are obtained.

[0020] Further, in the step S5, the process of constructing the micro-grid user energy storage demand quantitative analysis model and the micro-grid group user energy storage demand quantitative analysis model with the power supply reliability optimization as the core target is as follows:

[0021] By identifying the source-load imbalance interval in the micro-grid user operation and quantifying the key characteristics including at least the area and the peak value, the demand energy storage capacity model and the demand energy storage power value model with the power supply reliability optimization as the target are constructed, and the lower limit of the demand energy storage capacity and the demand energy storage power value to ensure that the micro-grid user does not occur in the emergency support stage is obtained.

[0022] Further, in the step S5, the peak-valley arbitrage profit maximization constraint relationship of the micro-grid is as follows:

[0023] In the valley electricity price period, the micro-grid user charges the energy storage as much as possible, but the charging power should be less than the sum of the power transmission channel power of the micro-grid and the new energy redundant power of the micro-grid;

[0024] In the peak tariff period, the micro-grid user discharges as much as possible, but to avoid the power flow return, the discharge power of the micro-grid should be less than the net load power of the micro-grid;

[0025] At the same time, ensure that the total charging and discharging power of the single micro-grid is constant throughout the day to ensure the balance of the final state of the micro-grid user energy storage;

[0026] The peak-valley arbitrage revenue maximization constraint relationship of the micro-grid is expressed as:

[0027] The maximum charging rate of the micro-grid user energy storage should be greater than the sum of the maximum line transmission power and the excess power of new energy in the valley tariff period, and the maximum discharging power of the micro-grid user energy storage should be greater than the maximum net load power in the peak tariff period, so as to ensure that the charging and discharging rate of the micro-grid user energy storage will not cause the waste of its capacity;

[0028] The peak-valley arbitrage revenue maximization constraint relationship of the micro-grid group is expressed as:

[0029] On the user side of the micro-grid group, the discharging power of the energy storage should not exceed the sum of the net loads of each micro-grid.

[0030] Further, the constraint relationship between the local consumption rate of new energy and the demand energy storage capacity is:

[0031] In the daily time scale, the maximum charging power of the micro-grid user energy storage should be greater than the maximum excess power of photovoltaic; the demand energy storage capacity of the micro-grid user should not be lower than the preset value of the daily consumption rate;

[0032] In the annual time scale, considering the new energy consumption pressure interval of each typical day, the required energy storage capacity of the micro-grid user can ensure that the new energy consumption rate is not lower than the minimum annual consumption rate limit in the annual time scale.

[0033] Further, the optimal power supply reliability requires that the maximum discharging power of the single micro-grid user energy storage be greater than the instantaneous deficiency power of the single micro-grid user;

[0034] The demand energy storage capacity of the single micro-grid user energy storage is greater than the maximum value of the rolling integral of the power in the reliable power supply pressure interval of each time period.

[0035] Further, the new energy consumption pressure interval is the interval where the new energy output is greater than the load demand, and the reliable power supply pressure interval is the interval where the load demand is greater than the available power supply capacity.

[0036] A micro-grid group user energy storage demand quantitative analysis system for realizing the above-mentioned method steps, comprising:

[0037] A data acquisition and input unit is configured to acquire a plurality of typical days representing different operation characteristics of each micro-grid in the micro-grid group;

[0038] A source-load matching analysis unit is in communication connection with the data acquisition and input unit, configured to acquire a net load power curve of each micro-grid in each typical day, and obtain a difference between a load demand and a new energy output of each micro-grid at each time point based on the net load power curve;

[0039] A pressure interval identification unit is in communication connection with the source-load matching analysis unit, configured to identify a new energy consumption pressure interval and a reliable power supply pressure interval of the micro-grid based on the difference between the load demand and the new energy output at each time point;

[0040] An energy storage complementary window interval identification unit is in communication connection with the source-load matching analysis unit, configured to superimpose the net load power curve of each micro-grid in each typical day, analyze time misalignment characteristics of the new energy consumption pressure and the reliable power supply pressure between two micro-grids, and identify an energy storage complementary window interval that can be shared and utilized by the micro-grid group users;

[0041] An energy storage demand quantification unit is in communication connection with the pressure interval identification unit and the energy storage complementary window interval identification unit, and is configured to, based on the new energy consumption pressure interval, the reliable power supply pressure interval, and the energy storage complementary window interval that can be shared and utilized by the micro-grid group users, construct a micro-grid user energy storage demand quantification analysis model and a micro-grid group user energy storage demand quantification analysis model respectively with economic optimization, environmental optimization and power supply reliability optimization as three core targets, so as to obtain a demand energy storage capacity and a demand energy storage power value of the micro-grid user and the micro-grid group user under corresponding targets;

[0042] A comprehensive demand quantification unit is in communication connection with the energy storage demand quantification unit, configured to compare and analyze a critical value of a first demand energy storage capacity and a critical value of a first demand energy storage power value obtained by the micro-grid user under different target combinations, to obtain a first energy storage comprehensive demand value of the micro-grid user under the corresponding target combination; and compare and analyze a critical value of a second demand energy storage capacity and a critical value of a second demand energy storage power value obtained by the micro-grid group user under economic optimization and environmental optimization two target combinations, to obtain a second energy storage comprehensive demand value of the micro-grid group user under the economic optimization and environmental optimization two target combinations.

[0043] The present application has the following beneficial effects compared with the prior art:

[0044] 1. The present application fuses the economic optimality, environmental optimality and power supply reliability as three core targets, respectively constructs a micro-grid user energy storage demand quantitative analysis model and a micro-grid group user energy storage demand quantitative analysis model, so as to obtain the demand energy storage capacity and demand energy storage power value of the micro-grid user and the micro-grid group user under the corresponding target; fully considering the difference and complementarity of the source and load characteristics of the micro-grid group, quantifying the comprehensive energy storage demand of the user side under the shared energy storage mode of the micro-grid group.

[0045] 2. The present application obtains the first energy storage comprehensive demand value of the micro-grid user under the corresponding target combination by comparing and analyzing the critical value of the first demand energy storage capacity and the critical value of the first demand energy storage power value obtained by the micro-grid user under different target combinations; obtains the second energy storage comprehensive demand value of the micro-grid group user under the economic optimality and environmental optimality two target combinations by comparing and analyzing the critical value of the second demand energy storage capacity and the critical value of the second demand energy storage power value obtained by the micro-grid group user under the economic optimality and environmental optimality two target combinations, forming an energy storage demand analysis method that gives critical values considering multi-dimensional targets and covering independent and shared operation modes. BRIEF DESCRIPTION OF DRAWINGS

[0046] The present application will be further described below in combination with the drawings:

[0047] Figure 1 It is a flowchart of the method of the present application;

[0048] Figure 2 It is a schematic diagram of the micro-grid one new energy consumption pressure and reliable power supply pressure quantitative interval of the embodiment of the present application;

[0049] Figure 3 It is a schematic diagram of the micro-grid two new energy consumption pressure and reliable power supply pressure quantitative interval of the embodiment of the present application;

[0050] Figure 4 It is a schematic diagram of the micro-grid three new energy consumption pressure and reliable power supply pressure quantitative interval of the embodiment of the present application;

[0051] Figure 5 It is a schematic diagram of the micro-grid group whole source and load power matching condition of the embodiment of the present application including the micro-grid one, the micro-grid two and the micro-grid three;

[0052] Figure 6 It is a schematic diagram of the system of the present application. DETAILED DESCRIPTION

[0053] In the description of the present application, it needs to be understood that the relative positional or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is a relative positional or positional relationship, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for description purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" and the like can be explicitly or implicitly included one or more. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0054] In the description of the present application, it needs to be understood that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood through specific circumstances.

[0055] As shown in Figures 1 to 6 The present application provides a micro-grid group user energy storage demand quantification analysis method, comprising the following steps:

[0056] Step S1, obtaining a plurality of typical days representing different operating characteristics of each micro-grid in the micro-grid group.

[0057] Specifically comprising the following steps:

[0058] Step S11, obtaining the topology structure of the micro-grid group, the topology structure of the micro-grid group at least comprising a plurality of micro-grids, a superior distribution network and on-demand configured independent energy storage units and shared energy storage units, and obtaining the basic data of each micro-grid, such as predicted load, distributed new energy predicted power generation, electricity price curve and line transmission capacity;

[0059] Step S12, obtaining a plurality of typical days representing different operating characteristics of each micro-grid, such as each quarter, weekday / weekend and operating condition; according to the pre-stored annual statistical data of different operating characteristics, the frequency of each typical day can be analyzed, which can reflect the annual operating characteristics of the micro-grid group users.

[0060] Step S2, the net load power curve of each micro-grid in each typical day is obtained, and the difference between the load demand and the new energy output of each micro-grid at each time is obtained based on the net load power curve.

[0061] Step S3, based on the difference between the load demand and the new energy output at each time, the new energy consumption pressure interval and the reliable power supply pressure interval of the micro-grid are identified. The new energy consumption pressure interval is the interval in which the new energy output is greater than the load demand, and the reliable power supply pressure interval is the interval in which the load demand is greater than the available power supply capacity.

[0062] Step S4, superimposing the net load power curve of each micro-grid in each typical day, the time misalignment characteristics of the new energy consumption pressure and the reliable power supply pressure between the micro-grids are analyzed, and the energy storage complementary window interval that can be shared and used by the micro-grid group users is identified.

[0063] Step S5, based on the new energy consumption pressure interval, the reliable power supply pressure interval, and the energy storage complementary window interval that can be shared and used by the micro-grid group users, the micro-grid user energy storage demand quantitative analysis model and the micro-grid group user energy storage demand quantitative analysis model are constructed respectively with the economic optimization, environmental optimization and power supply reliability optimization as the three core targets, so as to obtain the demand energy storage capacity and demand energy storage power value of the micro-grid user and the micro-grid group user under the corresponding target.

[0064] The micro-grid user energy storage demand quantitative analysis model includes a micro-grid user energy storage capacity demand quantitative analysis model and a micro-grid user power demand quantitative analysis model.

[0065] The micro-grid group user energy storage demand quantitative analysis model includes a micro-grid group user energy storage capacity demand quantitative analysis model and a micro-grid group user power demand quantitative analysis model.

[0066] In step S5, the process of constructing the micro-grid user energy storage demand quantitative analysis model and the micro-grid group user energy storage demand quantitative analysis model with economic optimization as the core target is as follows:

[0067] Based on the peak-valley arbitrage profit maximization constraint relationship of a single micro-grid and a micro-grid group, combined with the analysis results of the upper limit of charging power in the valley period and the upper limit of discharging power in the peak period, the micro-grid user energy storage demand quantitative analysis model with economic optimization as the target and the micro-grid group user energy storage demand quantitative analysis model with economic optimization as the target are constructed respectively, and the demand energy storage capacity and demand energy storage power value of the micro-grid user with economic optimization as the target, and the demand energy storage capacity and demand energy storage power value of the micro-grid group user with economic optimization as the target are obtained.

[0068] The peak-valley arbitrage profit maximization constraint relationship of the micro-grid is expressed as:

[0069] In the valley electricity price period, the micro-grid user stores energy as much as possible, but the charging power should be less than the sum of the micro-grid transmission channel power and the new energy redundant power of the micro-grid;

[0070] In the peak electricity price period, the micro-grid user discharges as much as possible, but to avoid the power flow returning, the discharge power of the micro-grid should be less than the net load power of the micro-grid;

[0071] At the same time, the comprehensive charging and discharging power of the single micro-grid is ensured to be constant throughout the day, so as to ensure the balance of the final state of the micro-grid user energy storage.

[0072] The quantitative analysis model of the micro-grid user energy storage capacity demand with the optimal economy as the target is:

[0073] ;

[0074] In the above formula, represents the energy storage demand capacity of the micro-grid user with the optimal economy as the target, and the subscript "dis" represents that the variable belongs to a single micro-grid user, and the same below; 、 respectively represent the maximum and minimum SOC (State of Charge, energy storage charge state) capacity values of the micro-grid user energy storage; represents the proportional coefficient between the SOC capacity of the micro-grid user energy storage and the rated capacity, which is determined by factors such as energy storage type selection; 、 、 respectively represent the energy storage SOC capacity, charging power and discharging power at t period; 、 respectively represent the charging and discharging efficiency of the micro-grid user energy storage; 、 respectively represent the peak and valley electricity price time set.

[0075] The maximum peak-valley arbitrage income constraint relationship of the micro-grid is expressed as the demand energy storage power value:

[0076] The maximum charging rate of the micro-grid user energy storage should be greater than the sum of the maximum line transmission power and the new energy excess power in the valley electricity price period, and the maximum discharging power of the micro-grid user energy storage should be greater than the maximum net load power in the peak electricity price period, so as to ensure that the charging and discharging rate of the micro-grid user energy storage will not cause the waste of its capacity.

[0077] The quantitative analysis model of the micro-grid user power demand with the optimal economy as the target is:

[0078] ;

[0079] In the above formula, Pmax,grid represents the maximum transmission power of the microgrid user transmission line; Pnew represents the output power of new energy at time period t; Pload represents the load power at time period t; represents the upward approximation operation.

[0080] The peak-valley arbitrage revenue maximization constraint relationship of the microgrid group is shown as follows:

[0081] For the microgrid group user connected to the distribution network, the demand capacity of the microgrid group user sharing energy storage is quantified. The operation rules are set as follows: on the side of the distribution network, the charging power of the energy storage is less limited under the peak-valley electricity price mechanism due to the sufficient transmission capacity of the distribution network; but on the side of the microgrid group user, the discharging power of the energy storage needs to be limited to ensure the power supply of the microgrid group user, and cannot exceed the sum of the net loads of the microgrids. Based on this constraint, the quantification analysis model of the demand capacity of the microgrid group user energy storage with the economic optimization as the target is as follows:

[0082] ;

[0083] In the above formula, represents the demand capacity of the microgrid group user energy storage with the economic optimization as the target; , respectively represent the maximum and minimum SOC capacity values of the microgrid group user energy storage; represents the proportional coefficient between the SOC capacity and the rated capacity of the microgrid group user energy storage, which is determined by factors such as the type of energy storage; , , respectively represent the SOC capacity, charging power and discharging power of the energy storage at time period t; , respectively represent the charging and discharging efficiencies of the microgrid group user energy storage; , respectively represent the peak and valley electricity price time sets.

[0084] The quantification analysis model of the power demand of the microgrid group user with the economic optimization as the target is as follows:

[0085] ;

[0086] ;

[0087] In the above formula, represents the set of microgrid users; , respectively represent the load power and new energy power of a single microgrid user i at time period t; represents the number of time periods of energy storage discharging.

[0088] In step S5, the process of constructing the microgrid user energy storage demand quantification analysis model and the microgrid group user energy storage demand quantification analysis model with the optimal environmental protection as the core goal is as follows:

[0089] Based on the constraint relationship between the local consumption rate of new energy and the demand energy storage capacity, the microgrid user energy storage demand quantification analysis model with the optimal environmental protection as the goal and the microgrid group user energy storage demand quantification analysis model with the optimal environmental protection as the goal are constructed, respectively, to obtain the microgrid user demand energy storage capacity and demand energy storage power value with the optimal environmental protection as the goal, and the microgrid group user demand energy storage capacity and demand energy storage power value with the optimal environmental protection as the goal.

[0090] The constraint relationship between the local consumption rate of new energy and the demand energy storage capacity is as follows:

[0091] In the daily time scale, the maximum charging power of the microgrid user energy storage should be greater than the maximum excess power of the photovoltaic; the demand energy storage capacity of the microgrid user should not be lower than the daily consumption rate preset value.

[0092] In the annual time scale, the new energy consumption pressure interval of each typical day is comprehensively considered to ensure that the energy storage capacity required by the microgrid user can meet the new energy consumption rate not lower than the minimum annual consumption rate limit in the annual time scale.

[0093] Specifically, in the independent investment mode adopted by the microgrid user:

[0094] In the daily time scale, the constraint relationship between the local consumption rate of new energy and the demand energy storage capacity of the microgrid user is shown in the demand energy storage power value as follows:

[0095] The maximum charging power of the microgrid user energy storage should be greater than the maximum excess power of the photovoltaic.

[0096] The quantification analysis model of the microgrid user power demand with the optimal environmental protection as the goal is as follows:

[0097] ;

[0098] In the above formula, represents the demand charging power of the microgrid user energy storage with the optimal environmental protection as the goal, and the subscript "dis" represents that the variable belongs to a single microgrid, and the same below; represents the output power of the new energy in the microgrid in the d typical day t period; represents the load power of the microgrid user in the d typical day t period; represents a set of typical days; represents a set of time periods in which the microgrid user has new energy consumption pressure in the d typical day.

[0099] On a daily timescale, the constraint relationship between the local renewable energy consumption rate and the required energy storage capacity for microgrid users is expressed as follows:

[0100] The energy storage capacity required by microgrid users should not be less than the preset daily consumption rate. The basic idea is as follows: Figure 2 As shown, the area of ​​the renewable energy absorption pressure zone for microgrid users on each typical day represents the excess electricity resulting from the inability of distributed renewable energy to be absorbed locally. This corresponds to the energy storage capacity configuration requirement for microgrid users—the required energy storage capacity for microgrid users should be greater than the area of ​​the renewable energy absorption pressure zone. Based on this idea, a quantitative analysis model for the energy storage capacity requirement of microgrid users, with optimal environmental performance as the objective, is determined on a daily time scale as follows:

[0101] ;

[0102] In the above formula, This represents the energy storage capacity required by microgrid users with the goal of optimal environmental performance on a daily timescale. This represents the initial SOC capacity of microgrid user demand energy storage at the beginning of the absorption pressure range on the d-th typical day, with the goal of optimal environmental performance. This represents the proportion of power absorbed by energy storage for microgrid users with optimal environmental performance on the d-th typical day, relative to the excess power of new energy sources; "Pr" indicates probability confidence calculation. This represents the percentage of the minimum daily absorption rate of new energy sources. This represents the time set of the d-th typical day; This indicates the minimum required confidence level.

[0103] On an annual timescale, the constraint relationship between the local renewable energy consumption rate and the required energy storage capacity for microgrid users is expressed in terms of required energy storage power as follows:

[0104] Taking into account the renewable energy absorption pressure range of each typical day, the energy storage capacity required by microgrid users is ensured to meet the minimum annual absorption rate limit on an annual time scale. Considering the temporal correlation between multiple typical days, the energy storage SOC capacity at the initial moment of the absorption pressure range in each typical day needs to be corrected. The basic idea is: if photovoltaic power is charged during the photovoltaic surplus period of a certain typical day, the minimum energy storage SOC capacity at the initial moment of the photovoltaic surplus period in the next typical day can be determined by assuming that the microgrid user's energy storage will remain in a discharging state for a period of time thereafter and calculating the maximum discharge amount. Based on this idea, the quantitative analysis model for the energy storage capacity demand of microgrid users with optimal environmental protection as the goal is determined on an annual time scale as follows:

[0105] ;

[0106] In the above formula, represents the micro-grid user energy storage demand capacity under the goal of optimal environmental protection in the annual time scale; represents the energy storage SOC capacity at the end of the consumption pressure period in each typical day; represents the new energy consumption rate of each typical day; represents the time set of no new energy consumption pressure period between each pair of typical days (as shown in Figure 2 ); represents the minimum consumption rate limit of new energy of the micro-grid user in the annual time scale.

[0107] Based on the above analysis, the micro-grid user energy storage demand energy storage power value and demand energy storage capacity under the goal of optimal environmental protection are:

[0108] .

[0109] Specifically, under the shared investment mode adopted by the micro-grid group user:

[0110] In the daily time scale, from the low-carbon environmental protection demand, the micro-grid group user energy storage demand is analyzed and quantified. The quantitative analysis model of the micro-grid group user power demand under the goal of optimal environmental protection is:

[0111] ;

[0112] In the above formula, represents the demand charging power of the micro-grid group user energy storage under the goal of optimal environmental protection; represents the set of each micro-grid; , respectively represent the load power and new energy power of a single micro-grid i at period t in typical day d.

[0113] In the daily time scale, the quantitative analysis model of the micro-grid group user energy storage capacity demand under the goal of optimal environmental protection is:

[0114] ;

[0115] In the above formula, represents the micro-grid group user energy storage demand capacity under the goal of optimal environmental protection in the daily time scale; represents the initial SOC capacity of the energy storage at the beginning time of the consumption pressure interval in the dth typical day; represents the proportion of the power absorbed by the energy storage in the single micro-grid user i to the new energy excess power in the dth typical day; represents the proportion of the daily minimum consumption rate of the new energy of the micro-grid group user; represents the time set of the dth typical day.

[0116] The quantitative analysis model of the energy storage capacity demand of the micro-grid group user with the optimal environmental protection as the target in the annual time scale is:

[0117]

[0118] In the above formula, represents the energy storage demand capacity of the micro-grid group user with the optimal environmental protection as the target in the annual time scale; represents the SOC capacity of the energy storage at the end time of the pressure period of new energy consumption in the dth typical day; represents the new energy consumption rate of each typical day; represents the time set of the pressure period of new energy consumption between two typical days; represents the minimum consumption proportion of the micro-grid group in the annual time scale of new energy.

[0119] According to the above analysis, the energy storage power value and the energy storage capacity demand of the micro-grid group user with the optimal environmental protection as the target are:

[0120] .

[0121] In step S5, the process of constructing the quantitative analysis model of the energy storage demand of the micro-grid user and the quantitative analysis model of the energy storage demand of the micro-grid group user with the optimal power supply reliability as the core target is:

[0122] In order to meet the optimal power supply reliability of the micro-grid user, the key characteristics of the source-load imbalance interval in the operation of the micro-grid user are identified and quantified, including the area and the peak value. The demand energy storage capacity model and the demand energy storage power value model with the optimal power supply reliability as the target are constructed, and the lower limit of the demand energy storage capacity and the demand energy storage power value to ensure that the micro-grid user does not occur in the emergency support stage is obtained.

[0123] The maximum discharge power of the single micro-grid user energy storage is greater than the instantaneous power shortage of the single micro-grid user in order to meet the optimal power supply reliability of the micro-grid user;

[0124] The demand energy storage capacity of the single micro-grid user energy storage is greater than the maximum value of the rolling integral of the power in the reliable power supply pressure interval of each time period.

[0125] Specifically, due to the start-up delay of the micro-turbine in the micro-grid group, when the micro-grid group needs to be disconnected from the power distribution network and switched to an island operation state, the emergency power support needs to rely on the micro-grid group user energy storage in the time period from the "grid-connected-island state switching time" to the "time when the gas turbine has sufficient power support capacity". The duration of this process is defined as Considering that under the shared investment model, it cannot be guaranteed that the shared energy storage configured in the microgrid cluster can provide power support when any microgrid user enters islanded operation, this step only focuses on the independent investment model and establishes a quantitative analysis model of energy storage demand for a single microgrid user with the goal of optimal power supply reliability.

[0126] Figure 2 The height of the reliable power supply pressure range in each time period corresponds to the power deficit that a single microgrid user may experience when operating off-grid, i.e., the power demand value of the microgrid user's energy storage. The maximum discharge power of the microgrid user's energy storage must be greater than the instantaneous power deficit of the microgrid user. Based on this, Using a time window as a reference, the power within the reliable power supply pressure range of each time period is integrally rolled. The area obtained from the integral corresponds to the energy storage capacity configuration requirement of microgrid users, meaning the energy storage capacity must be greater than the maximum value of the integral area. Based on the above approach, a quantitative analysis of the lower limit of the required energy storage capacity and required energy storage power for microgrid users, with the goal of optimal power supply reliability, is conducted:

[0127] The quantitative analysis model for microgrid user power demand with the goal of optimizing power supply reliability is as follows:

[0128] ;

[0129] In the above formula, This represents the required discharge power of energy storage for a single microgrid user with the goal of optimal power supply reliability. The scaling factor is used to characterize... The ratio between the rate of change of load power on a time scale and the rate of change of load power on an hourly time scale; The time set representing the period of reliable power supply pressure in a microgrid, such as Figure 2 As shown.

[0130] Regarding energy storage capacity, unlike the aforementioned energy storage capacity configuration based on the demand for renewable energy consumption, due to... Because the time frame is relatively short, the configuration is not affected by the time-series characteristics between multiple typical days; that is, there is no need to distinguish between intra-day and annual time-scale demands. Under these circumstances, a quantitative analysis model for the microgrid user energy storage capacity demand, with the goal of optimizing power supply reliability, is constructed as follows:

[0131] ;

[0132] In the above formula, This represents the energy storage capacity required by microgrid users with the goal of optimal power supply reliability. This represents the SOC capacity of the microgrid user's energy storage at time t on the d-th typical day.

[0133] Based on the above analysis, the lower limit value of the demand energy storage capacity and the demand energy storage power value of the single micro-grid user energy storage with the optimal power supply reliability as the target is:

[0134] .

[0135] Step S6, comparing and analyzing the critical value of the first demand energy storage capacity and the critical value of the first demand energy storage power value obtained by the micro-grid user under different target combinations, obtaining the first energy storage comprehensive demand value of the micro-grid user under the corresponding target combination; comparing and analyzing the critical value of the second demand energy storage capacity and the critical value of the second demand energy storage power value obtained by the micro-grid group user under the economic optimality and environmental protection optimality two target combinations, obtaining the second energy storage comprehensive demand value of the micro-grid group user under the economic optimality and environmental protection optimality two target combinations.

[0136] Specifically, under the independent investment mode adopted by the micro-grid user:

[0137] When the single micro-grid user hopes to meet the two core targets of economic optimality and environmental protection optimality, the first energy storage comprehensive demand value coupled with economic and environmental protection demand is:

[0138] ;

[0139] In the formula, is the critical value of the first demand energy storage power value when the single micro-grid user hopes to meet the two core targets of economic optimality and environmental protection optimality; is the critical value of the first demand energy storage capacity when the single micro-grid user hopes to meet the two core targets of economic optimality and environmental protection optimality.

[0140] When the single micro-grid user hopes to meet the two core targets of economic optimality and power supply reliability optimality, the first energy storage comprehensive demand value coupled with economic and power supply reliability demand is:

[0141] ;

[0142] In the formula, is the critical value of the first demand energy storage power value when the single micro-grid user hopes to meet the two core targets of economic optimality and power supply reliability optimality, is the critical value of the first demand energy storage capacity when the single micro-grid user hopes to meet the two core targets of economic optimality and power supply reliability optimality.

[0143] When the single micro-grid user hopes to meet the three core targets of economic optimality, environmental protection optimality and power supply reliability optimality, the first energy storage comprehensive demand value coupled with economic, environmental protection and power supply reliability demand is:

[0144] ;

[0145] In the formula, is the critical value of the first demand energy storage capacity when the single micro-grid user wants to meet the three core targets of economic optimization, environmental optimization, and power supply reliability optimization.

[0146] A micro-grid group user energy storage demand quantification analysis system for implementing the above method steps, comprising:

[0147] A data acquisition and input unit for acquiring multiple typical days of each micro-grid in the micro-grid group representing different operating characteristics.

[0148] A source-load matching analysis unit in communication connection with the data acquisition and input unit, for acquiring the net load power curve of each micro-grid in each typical day, and based on the net load power curve, obtaining the difference between the load demand and new energy output of each micro-grid at each time.

[0149] A pressure interval identification unit in communication connection with the source-load matching analysis unit, for identifying the new energy consumption pressure interval and reliable power supply pressure interval of the micro-grid based on the difference between the load demand and new energy output at each time.

[0150] A energy storage complementary window interval identification unit in communication connection with the source-load matching analysis unit, for superimposing the net load power curve of each micro-grid in each typical day to analyze the time misalignment characteristics of new energy consumption pressure and reliable power supply pressure between two micro-grids, and identifying the energy storage complementary window interval that can be shared by the micro-grid group users.

[0151] An energy storage demand quantification unit in communication connection with the pressure interval identification unit and the energy storage complementary window interval identification unit, the energy storage demand quantification unit being configured to, based on the new energy consumption pressure interval, the reliable power supply pressure interval, and the energy storage complementary window interval that can be shared by the micro-grid group users, construct a micro-grid user energy storage demand quantification analysis model and a micro-grid group user energy storage demand quantification analysis model respectively with economic optimization, environmental optimization, and power supply reliability optimization as the three core targets, so as to obtain the demand energy storage capacity and demand energy storage power value of the micro-grid user and the micro-grid group user under the corresponding target.

[0152] Specifically, the micro-grid user energy storage demand quantification analysis model includes a micro-grid user energy storage capacity demand quantification analysis model and a micro-grid user power demand quantification analysis model.

[0153] The micro-grid group user energy storage demand quantification analysis model includes a micro-grid group user energy storage capacity demand quantification analysis model and a micro-grid group user power demand quantification analysis model.

[0154] The comprehensive demand quantifying unit is in communication connection with the energy storage demand quantifying unit, is used for comparing and analyzing the critical value of the first demand energy storage capacity and the critical value of the first demand energy storage power value obtained by the micro-grid user under different target combinations, and obtaining the first energy storage comprehensive demand value of the micro-grid user under the corresponding target combination; comparing and analyzing the critical value of the second demand energy storage capacity and the critical value of the second demand energy storage power value obtained by the micro-grid group user under the two target combinations of the economic optimality and the environmental protection optimality, and obtaining the second energy storage comprehensive demand value of the micro-grid group user under the two target combinations of the economic optimality and the environmental protection optimality.

[0155] It should be noted that the connection relationship between the components and modules used in the present application is definite and can be realized. Except for the special description in the embodiments, the specific connection relationship can bring corresponding technical effects, and based on the premise of not relying on the execution of the corresponding software program, the technical problems proposed in the present application are solved. The model of the components, modules, specific elements, the connection mode between them, and the conventional use method and the expected technical effects brought by the above technical features, except for the specific description, all belong to the public contents disclosed in the patents, journal papers, technical manuals, technical dictionaries, textbooks, and other existing technologies obtained by the skilled in the art before the application date, or belong to the conventional technology and common knowledge in the art, and do not need to be described in detail. Therefore, the technical solutions provided in the present application are clear, complete, and realizable, and the corresponding physical products can be reproduced or obtained according to the technical means.

[0156] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A micro-grid group user energy storage demand quantification analysis method, characterized in that, The method comprises the following steps: Step S1, obtaining multiple typical days representing different operating characteristics of each micro-grid in the micro-grid group; Step S2, obtaining the net load power curve of each micro-grid in each typical day, and obtaining the difference between the load demand and the new energy output of each micro-grid at each time point based on the net load power curve; Step S3, identifying the new energy consumption pressure interval and the reliable power supply pressure interval of the micro-grid based on the difference between the load demand and the new energy output at each time point; Step S4, superimposing the net load power curves of each micro-grid in each typical day to analyze the time misalignment characteristics of the new energy consumption pressure and the reliable power supply pressure between each pair of micro-grids, and identifying the energy storage complementary window interval that can be shared by the micro-grid group users; Step S5, based on the new energy consumption pressure interval, the reliable power supply pressure interval, and the energy storage complementary window interval that can be shared by the micro-grid group users, taking economic optimization, environmental optimization, and power supply reliability optimization as the three core targets, respectively constructing a micro-grid user energy storage demand quantitative analysis model and a micro-grid group user energy storage demand quantitative analysis model, and obtaining the demand energy storage capacity and demand energy storage power value of the micro-grid user and the micro-grid group user under the corresponding target; Step S6, comparing and analyzing the critical value of the first demand energy storage capacity and the critical value of the first demand energy storage power value obtained by the micro-grid user under different target combinations to obtain the first energy storage comprehensive demand value of the micro-grid user under the corresponding target combination; comparing and analyzing the critical value of the second demand energy storage capacity and the critical value of the second demand energy storage power value obtained by the micro-grid group user under the economic optimization and environmental optimization target combination to obtain the second energy storage comprehensive demand value of the micro-grid group user under the economic optimization and environmental optimization target combination.

2. The method of claim 1, wherein, The micro-grid user energy storage demand quantitative analysis model comprises a micro-grid user energy storage capacity demand quantitative analysis model and a micro-grid user power demand quantitative analysis model; The micro-grid group user energy storage demand quantitative analysis model comprises a micro-grid group user energy storage capacity demand quantitative analysis model and a micro-grid group user power demand quantitative analysis model.

3. The method of claim 2, wherein, In the step S5, the process of constructing the micro-grid user energy storage demand quantitative analysis model and the micro-grid group user energy storage demand quantitative analysis model with economic optimization as the core target is as follows: Based on the peak-valley arbitrage revenue maximization constraint relationship of a single micro-grid and a micro-grid group, and combined with the analysis results of the upper limit of the charging power in the valley period and the upper limit of the discharging power in the peak period, the micro-grid user energy storage demand quantitative analysis model with economic optimization as the target and the micro-grid group user energy storage demand quantitative analysis model with economic optimization as the target are constructed, and the demand energy storage capacity and demand energy storage power value of the micro-grid user with economic optimization as the target and the demand energy storage capacity and demand energy storage power value of the micro-grid group user with economic optimization as the target are obtained.

4. The method of claim 2, wherein, In the step S5, the process of constructing the micro-grid user energy storage demand quantitative analysis model and the micro-grid group user energy storage demand quantitative analysis model with environmental optimization as the core target is as follows: Based on the constraint relationship between the local consumption rate of new energy and the demand energy storage capacity, a micro-grid user energy storage demand quantitative analysis model with the optimal environmental protection as the target and a micro-grid group user energy storage demand quantitative analysis model with the optimal environmental protection as the target are constructed, and the demand energy storage capacity and demand energy storage power value of the micro-grid user with the optimal environmental protection as the target and the demand energy storage capacity and demand energy storage power value of the micro-grid group user with the optimal environmental protection as the target are obtained.

5. The method of claim 2, wherein, In the step S5, the process of constructing the micro-grid user energy storage demand quantitative analysis model and the micro-grid group user energy storage demand quantitative analysis model with the optimal power supply reliability as the core target is as follows: By identifying the source-load imbalance interval in the operation of the micro-grid user and quantifying the key characteristics including at least the area and the peak value, a demand energy storage capacity model and a demand energy storage power value model with the optimal power supply reliability as the target are constructed, and the lower limit of the demand energy storage capacity and the demand energy storage power value to ensure that the micro-grid user does not occur in the emergency support stage is obtained.

6. The method of claim 3, wherein the method further comprises: In the step S5, the peak-valley arbitrage yield maximization constraint relationship of the micro-grid is as follows in the demand energy storage capacity: In the valley electricity price period, the micro-grid user charges the energy storage as much as possible, but the charging power should be less than the sum of the power transmission channel power of the micro-grid and the new energy redundant power of the micro-grid; In the peak electricity price period, the micro-grid user discharges as much as possible, but to avoid the power flow return, the discharge power of the micro-grid should be less than the net load power of the micro-grid; At the same time, the comprehensive charging and discharging power of the single micro-grid is ensured to be constant throughout the day, so as to ensure the balance of the final state of the micro-grid user energy storage; The peak-valley arbitrage yield maximization constraint relationship of the micro-grid is as follows in the demand energy storage power value: The maximum charging rate of the micro-grid user energy storage should be greater than the sum of the maximum line transmission power and the new energy excess power in the valley electricity price period, and the maximum discharging power of the micro-grid user energy storage should be greater than the maximum net load power in the peak electricity price period, so as to ensure that the charging and discharging rate of the micro-grid user energy storage will not cause the waste of its capacity; The peak-valley arbitrage yield maximization constraint relationship of the micro-grid group is as follows in the demand energy storage capacity: On the micro-grid group user side, the discharging power of the energy storage should not exceed the sum of the net loads of each micro-grid. 7.The micro-grid group user energy storage demand quantification analysis method according to claim 4, characterized in that, The constraint relationship between the local consumption rate of new energy and the demand energy storage capacity is as follows: In the daily time scale, the maximum charging power of the micro-grid user energy storage should be greater than the maximum excess power of the photovoltaic; the demand energy storage capacity of the micro-grid user should not be lower than the preset value of the daily consumption rate; In the annual time scale, the required energy storage capacity of the micro-grid user is ensured to meet the new energy consumption rate not lower than the minimum annual consumption rate limit value in the annual time scale by comprehensively considering the new energy consumption pressure interval of each typical day. 8.The micro-grid group user energy storage demand quantification analysis method according to claim 5, characterized in that, The optimal power supply reliability is that the maximum discharging power of the single micro-grid user energy storage is greater than the instantaneous deficiency power of the single micro-grid user; The demand energy storage capacity of the single micro-grid user energy storage is greater than the maximum value of the rolling integral of the power in the reliable power supply pressure interval of each time period. 9.The micro-grid group user energy storage demand quantification analysis method according to claim 1, characterized in that, The new energy consumption pressure interval is the interval in which the new energy output is greater than the load demand, and the reliable power supply pressure interval is the interval in which the load demand is greater than the available power supply capacity.

10. A micro-grid group user energy storage demand quantification analysis system, characterized in that, For implementing the method steps as claimed in claims 1-9, comprising: a data acquisition and input unit configured to acquire a plurality of typical days representing different operating characteristics of each micro-grid in the micro-grid group; a source-load matching analysis unit in communication connection with the data acquisition and input unit, configured to acquire a net load power curve of each micro-grid in each typical day, and based on the net load power curve, obtain a difference between a load demand and a new energy output of each micro-grid at each time; a pressure interval identification unit in communication connection with the source-load matching analysis unit, configured to identify a new energy consumption pressure interval and a reliable power supply pressure interval of the micro-grid based on the difference between the load demand and the new energy output at each time; a storage complementary window interval identification unit in communication connection with the source-load matching analysis unit, configured to superimpose the net load power curves of each micro-grid in each typical day to analyze time misalignment characteristics of the new energy consumption pressure and the reliable power supply pressure between two micro-grids, and identify a storage complementary window interval that can be shared by the micro-grid group users; a storage demand quantification unit in communication connection with the pressure interval identification unit and the storage complementary window interval identification unit, the storage demand quantification unit being configured to, based on the new energy consumption pressure interval, the reliable power supply pressure interval, and the storage complementary window interval that can be shared by the micro-grid group users, construct a micro-grid user storage demand quantification analysis model and a micro-grid group user storage demand quantification analysis model respectively with economic optimization, environmental optimization, and power supply reliability optimization as three core targets, so as to obtain a demand storage capacity and a demand storage power value of the micro-grid user and the micro-grid group user under the corresponding targets; a comprehensive demand quantification unit in communication connection with the storage demand quantification unit, configured to compare and analyze a critical value of a first demand storage capacity and a critical value of a first demand storage power value obtained by the micro-grid user under different target combinations, to obtain a first storage comprehensive demand value of the micro-grid user under the corresponding target combinations; and compare and analyze a critical value of a second demand storage capacity and a critical value of a second demand storage power value obtained by the micro-grid group user under economic optimization and environmental optimization two target combinations, to obtain a second storage comprehensive demand value of the micro-grid group user under the economic optimization and environmental optimization two target combinations.

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