Multi-energy-flow flexibility level transmission and decomposition method of integrated energy system

Abstract

The invention discloses a multi-energy-flow flexibility hierarchical transmission and decomposition method for an integrated energy system. The method comprises the following steps: S1, establishing a correlation model of the integrated energy system according to an input and output coupling relationship among'source-network-load-storage 'equipment; s2, establishing a flexibility unified quantification model of different types of equipment of equipment hierarchy "source-network-load-storage"; s3, establishing an energy flow flexibility model of the energy flow level based on the equipment flexibility model; s4, establishing a system flexibility quantification model of the system level based on the energy flow flexibility model; s5, decomposing the system flexibility to the energy flow flexibility according to the upward / downward adjustment system flexibility index; and S6, decomposing the energy flow flexibility to the equipment flexibility according to the up / down regulation energy flow flexibility index. By adopting the method disclosed by the invention, the whole process of'source-network-load-storage 'and the multi-level flexibility quantification of'equipment-energy flow-system' can be realized, and the flexible operation regulation and control efficiency of the comprehensive energy system is improved.

Description

Technical Field

[0001] The present invention belongs to the field of operation and control of integrated energy systems, and in particular relates to a multi-energy flow flexibility hierarchical transmission and decomposition method for integrated energy systems. Background Art

[0002] Facing the "dual carbon" goal and the construction of a new energy system, integrated energy systems covering multiple energy flows such as electricity, heat (cold), and gas (steam) have received increasing attention due to their multi-energy complementary characteristics and comprehensive integration advantages. However, the structural diversity and scale expansion of integrated energy systems have brought about a leap in the complexity of accurate modeling and operation and regulation. How to tap the flexibility potential in integrated energy systems, quantify the flexibility indicators of the entire process of "source-grid-load-storage" and the multi-level "equipment-energy flow-system", and form flexibility transfer and decomposition calculation methods between different processes and levels have become issues that need to be solved urgently.

[0003] At present, the quantification of the flexibility of various energy systems at home and abroad is concentrated on power systems and building energy systems. The flexibility of power systems mainly focuses on the balance of supply and demand of power systems. The flexibility research of building energy systems is closely related to building demand response, mainly exploring flexibility resources such as equipment and building thermal inertia. There have been a small number of flexibility quantification studies on the planning, design and operation and regulation processes in heating systems, but the quantification of multi-energy flow flexibility in integrated energy systems is rare. At the same time, existing research focuses on the flexibility quantification of a certain link or equipment, lacking the flexibility quantification of the whole process of "source-grid-load-storage" and the multi-level "equipment-energy flow-system". Therefore, it is crucial to propose a transfer and decomposition calculation method for the flexibility of multi-energy flows in integrated energy systems to solve the problem of quantifying and improving the flexibility of multi-energy flows under different scenarios and working conditions, which is crucial to realizing the flexible operation and regulation of integrated energy systems. Summary of the invention

[0004] The purpose of the present invention is to provide a method for calculating the flexibility transfer and decomposition of a multi-energy flow system, by establishing a general flexibility quantification method for each link of the "source-grid-load-storage" and the "equipment-energy flow-system" multi-level of the integrated energy system, to form a transfer and decomposition mechanism for the flexibility of multi-energy flows in the integrated energy system. To achieve the above purpose, the present invention proposes the following technical solutions:

[0005] A multi-energy flow flexibility hierarchical transmission and decomposition method for an integrated energy system comprises the following steps:

[0006] S1, establish a comprehensive energy system model based on the input-output coupling relationship between "source-grid-load-storage" devices;

[0007] S2, establish a unified quantitative model for the flexibility of different types of equipment at the equipment level "source-grid-load-storage";

[0008] S3, establishing an energy flow flexibility model at the energy flow level based on the unified flexibility quantification model obtained in step S2, wherein the energy flow flexibility model covers single device flexibility and device coupling flexibility;

[0009] S4, establishing a system flexibility quantification model at the system level based on the energy flow flexibility model obtained in step S3, wherein the system flexibility model covers single energy flow flexibility and energy flow coupling flexibility;

[0010] S5, based on the system flexibility quantification model at the system level, decomposing the system flexibility into energy flow flexibility according to the upward / downward adjustment system flexibility index, and obtaining upward / downward adjustment values ​​of single energy flow flexibility and energy flow coupling flexibility;

[0011] S6, based on the energy flow flexibility model of the energy flow level, decomposing the energy flow flexibility into device flexibility according to the upward / downward adjustment of the energy flow flexibility index, and obtaining the upward / downward adjustment values ​​of the single device flexibility and the device coupling flexibility.

[0012] In the above technical solution, further, in step S1, the integrated energy system covers four energy flows of electricity, heat, steam and compressed air, and the "source-grid-load-storage" equipment that participates in the flexible regulation during the operation of the system includes cogeneration units, extraction condensing and back pressure thermal power units, steam-driven air compressors, electric air compressors, hot water / steam / compressed air transportation networks, hot water storage tanks, steam accumulators, batteries and other energy storage equipment, as well as industrial enterprises and living and office buildings with flexible loads. The integrated energy system model is specifically as follows: the energy bus method is used to establish the integrated energy system model, and the energy flow input and output forms of the above-mentioned various types of multi-energy supply / conversion / storage / load equipment are connected to the electricity / heat / steam / compressed air energy bus according to the actual energy flow path in the integrated energy system to form an overall integrated energy system model.

[0013] Furthermore, in step S2-4, the quantified value of the flexibility of each level of equipment / energy flow / system is defined as equipment / energy flow / system flexibility.

[0014] Furthermore, in step S2: the equipment flexibility is determined by the deviation between the real-time working condition of the equipment and the design working condition, and the remaining adjustable working condition range of the equipment; the design working condition of the equipment is derived from the established day-ahead operation scheduling plan, and the remaining adjustable working condition of the equipment is determined by the absolute value of the difference between the safe working condition range and the current working condition during operation; the unified quantitative model of the flexibility of different types of equipment at the equipment level "source-grid-load-storage" is specifically as shown in formulas (1)-(2):

[0015]

[0016]

[0017] In the formula, F dev _ U and F dev _ L are the upward and downward flexibility of the equipment respectively; C r is the real-time working condition value of the equipment; C d is the design condition value; C max and C min They are the maximum and minimum ranges of the equipment’s safe operating range, respectively. For energy supply equipment, the flexibility comes from adjustable output power (kW); for energy flow transmission networks, the flexibility comes from adjustable transmission flow and temperature (kg / m 3 or °C); for energy storage equipment, its flexibility comes from the switching of storage / release processes and the adjustable energy storage capacity (kW·h); for user loads, its flexibility comes from the adjustable load of building clusters and the flexible production process load of enterprises in industrial parks (kW).

[0018] Furthermore, in step S3, the energy flow flexibility needs to consider the respective flexibility of the equipment involved in the production, transportation, storage and utilization of the energy flow and the influence of the equipment coupling in the energy flow network. The energy flow flexibility model at the energy flow level is specifically as shown in formulas (3)-(5):

[0019]

[0020] (t, j)∈C1={(x1, y1), (x2, y2)..., (x m ,y m )},x m ∈N + ,y m ∈N + (5)

[0021] In the formula, F flow_U and flow_L are the upward and downward flexibility of energy flow respectively; a i is the flexibility ratio coefficient of a single device; b j is the equipment coupling flexibility proportional coefficient; f is the equipment coupling flexibility calculation function; F dev_L,i and F dev_L,j are the downward flexibility values ​​of the i-th and j-th equipment under real-time working conditions respectively; F dev_U,i and F dev_U,jare the upward flexibility values ​​of the i-th and j-th equipment under the real-time working conditions, respectively; n is the number of equipment participating in flexible scheduling in the integrated energy system; m is the number of equipment pairs with energy flow coupling relationships; C1 is a set of equipment pairs with coupling relationships. The device coupling flexibility calculation function is obtained as follows: for each equipment pair in the C1 set, the equipment characteristic curve is searched based on the equipment real-time working point, the equipment coupling flexibility is determined, and the equipment coupling flexibility of each equipment under the working condition change from 0 to 100% is calculated. All values ​​are interpolated and fitted to form a historical data set of equipment real-time working points and equipment coupling flexibility. The real-time working point of the coupled equipment pair is used as the input feature, the equipment coupling flexibility is used as the predicted value, and the linear support vector machine algorithm is used to fit the equipment coupling flexibility calculation function, thereby realizing online and rapid calculation of equipment coupling flexibility.

[0022] Furthermore, in step S4: system flexibility includes the flexibility of each energy flow and the flexibility of energy flow coupling, and the flexibility of energy flow coupling is brought about by the multi-energy complementary coupling characteristics of energy conversion equipment represented by batteries, steam accumulators, hot water storage tanks, etc., and multi-energy supply equipment represented by trigeneration. The system flexibility quantitative model at the system level is specifically as shown in equations (6)-(8):

[0023]

[0024] (i,j)∈C2={(x1,y1),(x2,y2),...,(x M ,y M )} (8)

[0025] In the formula, F sys_U and F sys_L are the upward and downward flexibility of the system respectively; c i is the single energy flow flexibility proportional coefficient; d j is the energy flow coupling flexibility proportional coefficient; g is the energy flow coupling flexibility calculation function; F flow_U,i and F flow_U,j are the upward flexibility values ​​of the i-th and j-th energy flow real-time conditions respectively; F flow_L,i and F flow_L,jare the downward flexibility values ​​of the i-th and j-th energy flows under real-time working conditions, respectively; N is the number of energy flows participating in flexible scheduling in the integrated energy system; M is the number of energy flow pairs with energy flow coupling relationships; C2 is a set of energy flow pairs with coupling relationships. The energy flow coupling flexibility calculation function is obtained as follows: for each energy flow in the C2 set, the energy flow coupling flexibility is determined based on the energy flow real-time working point and the energy flow network dynamic model simulation, and the energy flow coupling flexibility of each energy flow under the working condition change from 0 to 100% is calculated. All values ​​are interpolated and fitted to form a historical data set of energy flow real-time working point and energy flow coupling flexibility. The energy flow real-time working point of the coupled energy flow pair is used as the input feature, and the energy flow coupling flexibility is used as the predicted value. The linear support vector machine algorithm is used to fit the energy flow coupling flexibility calculation function, thereby realizing the online rapid calculation of energy flow coupling flexibility.

[0026] Furthermore, in step S5, the system flexibility index is specifically the deviation between the current system flexibility and the future system flexibility; the system flexibility is decomposed into energy flow flexibility according to the upward / downward adjustment of the system flexibility index, and the specific decomposition formula is as follows:

[0027]

[0028] S∈{economy,carbon,flexibility,...}, (13)

[0029] Where, ΔF sys_U and ΔF sys_L are the flexibility indexes of the upward and downward adjustment systems respectively; Δg represents the difference in energy flow coupling flexibility before and after adjustment; ΔF flow_U，i is the upward adjustment energy flow flexibility index of the i-th energy flow; ΔF flow_L，i Opt is the downward adjustment energy flow flexibility index of the i-th energy flow; sys_U and Opt sys_L are the optimal objective function values ​​for the upward and downward decomposition of system flexibility respectively; S is the objective function, which can be different optimization objectives such as optimal economy, minimum carbon emissions or maximum adjustable flexibility potential.

[0030] In step S6, the energy flow flexibility index is the deviation between the current flexibility and future flexibility of the energy flow; the energy flow flexibility is decomposed into equipment flexibility according to the upward / downward adjustment of the energy flow flexibility index, and the specific decomposition formulas are as shown in equations (14)-(18).

[0031]

[0032]

[0033] S∈{economy,carbon,flexibility,…}, (18)

[0034] Where, ΔF flow_U and ΔF flow_L are the energy flow flexibility indicators for upward and downward adjustment respectively; Δf represents the difference in device coupling flexibility before and after adjustment; ΔF dev_U,i ΔF is the upward adjustment energy flow flexibility index of the i-th device; dev_L,i Opt is the upward adjustment energy flow flexibility index of the i-th device; flow_U and Opt flow_L are the optimal objective function values ​​for the upward and downward decomposition of energy flow flexibility respectively; S is the objective function, which can be different optimization objectives such as optimal economy, minimum carbon emissions or maximum adjustable flexibility potential.

[0035] Based on the upward / downward adjustment values ​​of single energy flow flexibility and energy flow coupling flexibility and the upward / downward adjustment values ​​of single device flexibility and device coupling flexibility decomposed by the method of the present invention, the system is adjusted. The specific method is: reducing or increasing the flexibility of each level by changing the storage and release mode and operating parameters of the energy storage device, and the multi-energy complementary mode of the device and energy flow.

[0036] The beneficial effects of the present invention are:

[0037] The present invention provides a method for the hierarchical transmission and decomposition of flexibility in a multi-energy flow system. The method can realize the transmission and decomposition quantification of multi-level flexibility in a large and complex integrated energy system, can effectively calculate the flexibility potential of multi-energy flows in the integrated energy system, and provide a flexible strategy for the operation and regulation from the overall system to a single device. The method of the present invention can intuitively quantify and calculate the flexibility potential in different links and levels of the integrated energy system, and clarify the flexibility transmission and decomposition mechanism between the "equipment-energy flow-system" levels. It is of great significance for the quantification of flexibility potential and the search for flexibility improvement paths in the operation and regulation process of the integrated energy system. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0039] Figure 1 It is the main step of the method of the present invention.

[0040] Figure 2 It is a schematic diagram of calculating the real-time flexibility up / down value of the device. DETAILED DESCRIPTION

[0041] like Figure 1 As shown, a multi-energy flow flexibility hierarchical transmission and decomposition method for an integrated energy system of the present invention comprises the following steps:

[0042] Step S1: Establish a comprehensive energy system model based on the input-output coupling relationship between the "source-grid-load-storage" devices. The comprehensive energy system covers four energy flows: electricity, heat, steam, and compressed air. The "source-grid-load-storage" devices that are flexibly regulated during the operation of the system include cogeneration units, extraction condensing and back pressure thermal power units, steam-driven air compressors, electric air compressors, hot water / steam / compressed air transportation networks, hot water storage tanks, steam accumulators, batteries and other energy storage devices, as well as industrial enterprises and living and office buildings with flexible loads.

[0043] Step S2: Establish a unified quantitative model for the flexibility of different types of equipment at the equipment level "source-grid-load-storage". Define the equipment flexibility quantitative value as equipment flexibility, such as Figure 2 As shown in Figure 1, the flexibility of the equipment is determined by the deviation between the real-time operating condition of the equipment and the design operating condition, and the remaining adjustable operating condition range of the equipment. The design operating condition of the equipment is derived from the established day-ahead operation scheduling plan, and the remaining adjustable operating condition of the equipment is determined by the absolute value of the difference between the safe operating condition range during operation and the current operating condition. The unified quantitative model of the flexibility of different types of equipment at the equipment level "source-grid-load-storage" is specifically as shown in formulas (1)-(2):

[0044]

[0045] In the formula, F dev_U and F dev_L are the upward and downward flexibility of the equipment respectively; C r is the real-time working condition value of the equipment; C d is the design condition value; C max and C min They are the maximum and minimum ranges of the equipment’s safe operating range, respectively. For energy supply equipment, the flexibility comes from adjustable output power (kW); for energy flow transmission networks, the flexibility comes from adjustable transmission flow and temperature (kg / m 3 or °C); for energy storage equipment, its flexibility comes from the switching of storage / release processes and the adjustable energy storage capacity (kW·h); for user loads, its flexibility comes from the adjustable load of building clusters and the flexible production process load of enterprises in industrial parks (kW).

[0046] Step S3: Based on the unified flexibility quantification model obtained in step S2, an energy flow flexibility model at the energy flow level is established, and the energy flow flexibility model covers the flexibility of a single device and the flexibility of device coupling. The energy flow flexibility quantification value is defined as the energy flow flexibility. The energy flow flexibility needs to consider the individual flexibility of the devices involved in the production, transportation, storage and utilization of the energy flow and the influence of device coupling in the energy flow network. The energy flow flexibility model at the energy flow level is specifically as shown in formulas (3)-(5):

[0047]

[0048]

[0049] (i, j)∈C1={(x1, y1), (x2, y2)..., (x m y m )},x m ∈N + ,y m ∈N + (5)

[0050] In the formula, F flow_U and F flow_L are the upward and downward flexibility of energy flow respectively; a i is the flexibility ratio coefficient of a single device; b j is the equipment coupling flexibility proportional coefficient; f is the equipment coupling flexibility calculation function; F dev_L，i and F dev_L，j are the downward flexibility values ​​of the i-th and j-th equipment under real-time working conditions respectively; F dev_U，i and F dev_U，j are the upward flexibility values ​​of the i-th and j-th equipment under the real-time working conditions, respectively; n is the number of equipment participating in flexible scheduling in the integrated energy system; m is the number of equipment pairs with energy flow coupling relationships; C1 is a set of equipment pairs with coupling relationships. The device coupling flexibility calculation function is obtained as follows: for each equipment pair in the C1 set, the equipment characteristic curve is searched based on the equipment real-time working point, the equipment coupling flexibility is determined, and the equipment coupling flexibility of each equipment under the working condition change from 0 to 100% is calculated. All values ​​are interpolated and fitted to form a historical data set of equipment real-time working points and equipment coupling flexibility. The real-time working point of the coupled equipment pair is used as the input feature, the equipment coupling flexibility is used as the predicted value, and the linear support vector machine algorithm is used to fit the equipment coupling flexibility calculation function, thereby realizing online and rapid calculation of equipment coupling flexibility.

[0051] Step S4: Establish a system-level system flexibility quantitative model based on the energy flow flexibility model obtained in step S3. The system flexibility quantitative value is defined as the system flexibility. In addition to considering the flexibility of each energy flow, the system flexibility also includes the energy flow coupling flexibility brought about by the multi-energy complementary coupling characteristics of energy conversion equipment represented by batteries, steam accumulators, hot water storage tanks, etc., and multi-energy supply equipment represented by trigeneration. The specific system flexibility quantitative model at the system level is as follows:

[0052]

[0053] (i, j)∈C2={(x1, y1), (x2, y2),..., (x M ,y M )} (8)

[0054] In the formula, F sys_U and F sys_L are the upward and downward flexibility of the system respectively; c i is the single energy flow flexibility proportional coefficient; d j is the energy flow coupling flexibility proportional coefficient; g is the energy flow coupling flexibility calculation function; F flow_U,i and F flow_U,j are the upward flexibility values ​​of the i-th and j-th energy flow real-time conditions respectively; F flow_L,i and F flow_L,j are the downward flexibility values ​​of the i-th and j-th energy flows under real-time working conditions, respectively; N is the number of energy flows participating in flexible scheduling in the integrated energy system; M is the number of energy flow pairs with energy flow coupling relationships; C2 is a set of energy flow pairs with coupling relationships. The energy flow coupling flexibility calculation function is obtained as follows: for each energy flow in the C2 set, the energy flow coupling flexibility is determined based on the energy flow real-time working point and the energy flow network dynamic model simulation, and the energy flow coupling flexibility of each energy flow under the working condition change from 0 to 100% is calculated. All values ​​are interpolated and fitted to form a historical data set of energy flow real-time working point and energy flow coupling flexibility. The energy flow real-time working point of the coupled energy flow pair is used as the input feature, and the energy flow coupling flexibility is used as the predicted value. The linear support vector machine algorithm is used to fit the energy flow coupling flexibility calculation function, thereby realizing the online rapid calculation of energy flow coupling flexibility.

[0055] S5: Based on the system flexibility quantification model at the system level, the system flexibility is decomposed into energy flow flexibility according to the upward / downward adjustment system flexibility index, and the upward / downward adjustment values ​​of the single device flexibility and the device coupling flexibility are obtained. The specific decomposition formulas are as follows:

[0056]

[0057] S∈{economy,carbon,flexibility,...}, (13)

[0058] Where, ΔF sys_U and ΔF sys_L are the flexibility indexes of the upward and downward adjustment systems respectively; Δg represents the difference in energy flow coupling flexibility before and after adjustment; ΔF flow_U,i is the upward adjustment energy flow flexibility index of the i-th energy flow; ΔF flow_L,i Opt is the downward adjustment energy flow flexibility index of the i-th energy flow; sys_U and Optsys_L are the optimal objective function values ​​for the upward and downward decomposition of system flexibility respectively; S is the optimization target, which can be different optimization targets such as optimal economy, minimum carbon emissions or maximum adjustable flexibility potential.

[0059] Step S6: Based on the energy flow flexibility model of the energy flow level, decompose the energy flow flexibility into device flexibility according to the upward / downward adjustment energy flow flexibility index to obtain the upward / downward adjustment values ​​of the single device flexibility and the device coupling flexibility. The specific decomposition formulas are as follows:

[0060]

[0061] S∈{economy,carbon,flexibility,…}, (18)

[0062] Where, ΔF flow_U and ΔF flow_L are the energy flow flexibility indicators for upward and downward adjustment respectively; Δf represents the difference in device coupling flexibility before and after adjustment; ΔF dev_U,i ΔF is the upward adjustment energy flow flexibility index of the i-th device; dev_L,i Opt is the upward adjustment energy flow flexibility index of the i-th device; flow_U and Opt flow_L are the optimal objective function values ​​of the upward and downward decomposition of energy flow flexibility; S is the objective function.

[0063] Based on the upward / downward adjustment values ​​of the single energy flow flexibility and energy flow coupling flexibility and the upward / downward adjustment values ​​of the single device flexibility and device coupling flexibility decomposed from the above steps S5 and S6, the system is adjusted. The specific method is: by changing the storage and release mode and operating parameters of the energy storage device, and the multi-energy complementary mode of the device and the energy flow, the flexibility of each level can be reduced or increased.

Claims

1. A multi-energy flow flexibility hierarchical transmission and decomposition method for an integrated energy system, characterized in that: The steps include: S1, establish a comprehensive energy system model based on the input-output coupling relationship between "source-grid-load-storage" devices; S2, establish a unified quantitative model for the flexibility of different types of equipment at the equipment level "source-grid-load-storage"; S3, establishing an energy flow flexibility model at the energy flow level based on the unified flexibility quantification model obtained in step S2, wherein the energy flow flexibility model covers single device flexibility and device coupling flexibility; S4, establishing a system flexibility quantification model at the system level based on the energy flow flexibility model obtained in step S3, wherein the system flexibility model covers single energy flow flexibility and energy flow coupling flexibility; S5, based on the system flexibility quantification model at the system level, decomposing the system flexibility into energy flow flexibility according to the upward / downward adjustment system flexibility index, and obtaining upward / downward adjustment values ​​of single energy flow flexibility and energy flow coupling flexibility; S6, based on the energy flow flexibility model of the energy flow level, decomposing the energy flow flexibility into device flexibility according to the upward / downward adjustment of the energy flow flexibility index, and obtaining the upward / downward adjustment values ​​of the single device flexibility and the device coupling flexibility.

2. According to claim 1, a multi-energy flow flexibility hierarchical transmission and decomposition method for an integrated energy system is characterized in that: In step S1: the integrated energy system covers four energy flows: electricity, heat, steam, and compressed air. The "source-grid-load-storage" equipment that is flexibly controlled during the operation of the system includes cogeneration units, extraction-condensing and back-pressure thermal power units, steam-driven air compressors, electric air compressors, hot water / steam / compressed air transportation networks, hot water storage tanks, steam accumulators, batteries, and industrial enterprises and living and office buildings with flexible loads.

3. The multi-energy flow flexibility hierarchical transmission and decomposition method of a comprehensive energy system according to claim 1 is characterized in that: The quantitative value of flexibility at each level of equipment / energy flow / system is defined as equipment / energy flow / system flexibility.

4. The multi-energy flow flexibility hierarchical transmission and decomposition method of a comprehensive energy system according to claim 3 is characterized in that: In step S2, the unified quantification model of the flexibility of different types of equipment at the equipment level "source-grid-load-storage" is specifically as shown in formulas (1)-(2): In the formula, F dev_U and F dev_L are the upward and downward flexibility of the equipment respectively; C r is the real-time working condition value of the equipment; C d is the design condition value; C max and C min They are the maximum and minimum ranges of the equipment's safe operating range respectively.

5. The multi-energy flow flexibility hierarchical transmission and decomposition method of a comprehensive energy system according to claim 3 is characterized in that: The step S3 is specifically as follows: the energy flow flexibility needs to consider the flexibility of the equipment involved in the production, transportation, storage and utilization of the energy flow and the influence of the equipment coupling in the energy flow network. The energy flow flexibility model of the energy flow level is specifically as shown in formulas (3)-(5): (i,j)∈C1={(x1,y1),(x2,y2),...,(x m ,y m )),x m ∈N + ,y m ∈N + (5) In the formula, F flow_U and F ffow_L are the upward and downward flexibility of energy flow respectively; a i is the flexibility ratio coefficient of a single device; b j is the device coupling flexibility proportionality factor; f is the equipment coupling flexibility calculation function; F dev_L，i and F dev_L，j are the downward flexibility values ​​of the i-th and j-th equipment under real-time working conditions respectively; F dev_U，i and F dev_U，j are the upward flexibility values ​​of the i-th and j-th equipment under real-time working conditions respectively; n is the number of equipment participating in flexible scheduling in the integrated energy system; m is the number of equipment pairs with energy flow coupling relationship; C1 is the set of equipment pairs with coupling relationship.

6. The multi-energy flow flexibility hierarchical transmission and decomposition method of a comprehensive energy system according to claim 3 is characterized in that: In step S4, the system flexibility quantification model at the system level is specifically as shown in equations (6)-(8): (i,j)∈C2={(x1,y1),(x2,y2),...,(x M ,y M )} (8) In the formula, F sys_U and F sys_L are the upward and downward flexibility of the system respectively; c i is the single energy flow flexibility proportional coefficient; d j is the energy flow coupling flexibility proportional coefficient; g is the energy flow coupling flexibility calculation function; F flow_U，i and F flow_U，j are the upward flexibility values ​​of the i-th and j-th energy flow real-time conditions respectively; F flow_L，i and F flow_L，j are the downward flexibility values ​​of the i-th and j-th energy flows under real-time conditions respectively; N is the number of energy flows participating in flexible scheduling in the integrated energy system; M is the number of energy flow pairs with energy flow coupling relationships; C2 is the set of energy flow pairs with coupling relationships.

7. The multi-energy flow flexibility hierarchical transmission and decomposition method of a comprehensive energy system according to claim 6 is characterized in that: In step S5, the system flexibility index is specifically the deviation between the current system flexibility and the future system flexibility; the system flexibility is decomposed into energy flow flexibility according to the upward / downward adjustment of the system flexibility index, and the specific decomposition formulas are as follows: S∈{economy, carbon, flexibility,..}, (13) Where, ΔF sys_U and ΔF sys_L are the flexibility indexes of the upward and downward adjustment systems, respectively; Δg represents the difference in energy flow coupling flexibility before and after adjustment; ΔF flow_U，i is the upward adjustment energy flow flexibility index of the i-th energy flow; ΔF flow_L，i Opt is the downward adjustment energy flow flexibility index of the i-th energy flow; sys_U and Opt sys_L are the optimal objective function values ​​of the upward and downward decomposition of system flexibility respectively; S is the objective function.

8. The multi-energy flow flexibility hierarchical transmission and decomposition method of a comprehensive energy system according to claim 5 is characterized in that: In step S6, the energy flow flexibility index is the deviation between the current flexibility of the energy flow and the future flexibility; the energy flow flexibility is decomposed into equipment flexibility according to the upward / downward adjustment of the energy flow flexibility index, and the specific decomposition formula is as follows: S∈{economy, carbon, flexibility,...}, (18) Where, ΔF flow_U and ΔF flow_L are the energy flow flexibility indicators for upward and downward adjustment respectively; Δf represents the difference in device coupling flexibility before and after adjustment; ΔF dev_U，i ΔF is the upward adjustment energy flow flexibility index of the i-th device; dev_L，i Opt is the upward adjustment energy flow flexibility index of the i-th device; flow_U and Opt flow_L are the optimal objective function values ​​of the upward and downward decomposition of energy flow flexibility; S is the objective function.

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