A method, device and medium for optimal regulation and control of a comprehensive energy system under varying conditions

Abstract

The present application relates to a kind of integrated energy system variable condition optimization control method, equipment and medium, to integrated energy system, the energy coupling relationship and operating characteristics of each equipment in system are analyzed, and the influence of integrated energy system load rate on energy conversion equipment efficiency is considered, equipment and energy transmission equipment are modeled, integrated energy system model is obtained, and in the modeling process, the variable condition characteristics of multiple same equipment are considered one by one using energy bus modeling method;Based on integrated energy system model, with the minimum integrated energy system cost as objective function and constraint is constructed;Based on objective function and constraint, the optimal output strategy of integrated energy system is solved, equipment and medium are used to realize the method described above.Compared with prior art, the present application considers the nonlinear variable condition characteristics of equipment and the output condition of multiple same equipment, and considers the variable condition characteristics of energy transmission equipment in the modeling process, so that the reliability and stability of the generated optimization strategy are higher.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of integrated energy system applications, and in particular to an integrated energy system variable working condition optimization control method, device and medium. BACKGROUND

[0002] Under the global climate change and multiple environmental pressures, the massive emission of greenhouse gases has led to the deterioration of the environment. With the energy utilization tending to be low-carbon transformation, it is developing in the direction of multi-energy complementation and energy cascade utilization. In this context, integrated energy system (IES) emerged as the times require. Integrated energy system first originated in the field of combined heat and power, focusing on the collaborative optimization of heat and power systems, and then gradually expanded and enriched, involving the collaborative complementation of multiple links such as production, transmission, storage, use and conversion of electricity, heat, cold, natural gas and other energy subsystems. As a multi-energy coupling system containing cold, heat, electricity, gas and other energies, IES involves energy conversion and energy transmission equipment, and can provide reliable, economic and low-carbon energy for IES users through unified planning and scheduling of the output of different equipment. With the change of energy demand and the continuous development of energy supply system, integrated energy system becomes more and more complex, which also makes the optimization and control of integrated energy system a research hotspot. For the multi-energy coupling integrated energy system, the energy consumption and production forms of each device are very diversified. The main purpose of studying the fine modeling of integrated energy system is to make the results of optimization and control more in line with the actual situation through the use of different variable working condition characteristics of each device in the system, and to make the operation of the IES system more economical and reliable. For example, Chinese patent application CN114943376A provides an integrated energy optimization utilization interval planning method, which constructs a model for different devices in the system, and in the construction process, takes the energy bus as the coupling node, constructs the system energy supply and utilization structure, and in the modeling process, considers the influence of the energy consumption of the energy transmission equipment on the scheduling, constructs the objective function based on the model, and solves the optimal scheduling after interval planning. Although it provides a more fine integrated energy system modeling, it still has the following problems: 1) After considering the nonlinear variable working condition characteristics of the device, the output of multiple same devices in the system is ignored, which makes the rationality of the output of multiple same devices questionable; 2) Although the optimization operation of the energy transmission equipment (such as water pump, fan) in the IES is concerned in the modeling process, in order to facilitate modeling of the energy transmission equipment, the frequency of the energy transmission equipment is set as a constant, but in actual production, the water flow is in variable working condition operation, and there is often a phenomenon of "big horse pulling small cart" causing a lot of energy waste.

[0003] Therefore, it is necessary to provide a comprehensive energy system optimization scheduling method considering the output conditions of multiple same devices in the system and the variable working condition characteristics of the energy transmission model. SUMMARY

[0004] The present application aims to overcome the defects of the prior art and provides a comprehensive energy system variable working condition optimization control method, device and medium, which constructs a comprehensive energy system containing cold, heat, electricity and multiple energy coupling according to the output characteristics of each device in the system modeling process, analyzes the energy coupling relationship and operating characteristics of each device in the system, the energy medium generation, conversion and use process, and performs fine modeling according to the variable working condition characteristics of the energy transmission device, so as to ensure that the output of each device in the system is reasonably distributed and energy waste does not occur.

[0005] The object of the present application can be achieved by the following technical solutions:

[0006] According to the first aspect of the present application, a comprehensive energy system variable working condition optimization control method is provided, the method comprising:

[0007] For the comprehensive energy system, the energy coupling relationship and operating characteristics of each device in the system are analyzed, and the influence of the load rate of the comprehensive energy system on the efficiency of the energy conversion device is considered, the device and the energy transmission device are modeled, and the comprehensive energy system model is obtained, and in the modeling process, the energy bus modeling method is used to consider the variable working condition characteristics of multiple same devices one by one;

[0008] Based on the comprehensive energy system model, a target function of minimizing the cost of the comprehensive energy system is constructed and constraints are constructed;

[0009] Based on the target function and the constraints, the optimal output strategy of the comprehensive energy system is solved.

[0010] As a preferred technical solution, the device includes a photovoltaic device, a gas internal combustion engine, a gas hot water boiler, a flue gas hot water type lithium bromide unit and a centrifugal cold water chiller, and the modeling method of the device includes:

[0011] For the photovoltaic device, the light intensity and working temperature of the working environment are obtained, and the model is constructed based on the light intensity and working temperature, which is:

[0012] ,

[0013] wherein, Pv(i,t) represents the power supply of the photovoltaic device i at time t; Pv(i,t) represents the rated power of the photovoltaic device; Pv(i,t) represents the actual light intensity in the environment of the photovoltaic device i at time t; Indicates the intensity of the light being tested; Indicates the temperature effect coefficient; This represents the actual photovoltaic operating temperature at time t in the environment where photovoltaic device i is located; Indicates the test operating temperature;

[0014] For the aforementioned gas-fired internal combustion engine, its electrical and thermal load rates are obtained, and a model is constructed based on these electrical and thermal load rates as follows:

[0015] ,

[0016] ,

[0017] ,

[0018] ,

[0019] in, This represents the electrical power output of the gas-fired internal combustion engine at time t; This represents the actual power generation efficiency of the gas-fired internal combustion engine at time t. This represents the power output of the gas-fired internal combustion engine at time t; This represents the slope of the i-th segment of the line that generates electricity at time t using a gas-fired internal combustion engine. This represents the electrical load rate of the gas-fired internal combustion engine at time t; This represents the intercept of the i-th segment of the line that generates electricity at time t using a gas-fired internal combustion engine; and Let represent the two endpoints of the i-th segment of the power generation line of the gas internal combustion engine at time t; This represents the electrical power output of the gas-fired internal combustion engine at time t; This represents the actual heating efficiency of the gas-fired internal combustion engine at time t. The slope of the i-th segment of the heating line at time t of the gas-fired internal combustion engine is shown in the table. This represents the electrical load rate of the gas-fired internal combustion engine at time t; This represents the intercept of the i-th segment of the heating line provided by the gas-fired internal combustion engine at time t; and Let represent the two endpoints of the i-th segment of the heating line of the gas internal combustion engine at time t;

[0020] For the aforementioned gas-fired hot water boiler, its load rate is obtained, and a model is constructed based on the load rate as follows:

[0021] ,

[0022] ,

[0023] in, This represents the output power of the gas-fired hot water boiler at time t; η (t) represents the efficiency of the gas-fired water boiler at time t; P (t) represents the natural gas power consumed by the gas-fired water boiler at time t; K (i) represents the slope of the i-th segment of the heating line of the gas-fired water boiler; L (t) represents the load rate at time t; B (i) represents the intercept of the i-th segment of the heating line of the gas-fired water boiler; and respectively represent the two end points of the i-th segment of the heating line;

[0024] For the flue gas water type lithium bromide unit, the model is established as follows:

[0025] ,

[0026] ,

[0027] wherein, P (t) represents the power of the flue gas water type lithium bromide unit at time t; η (t) represents the efficiency of the flue gas water type lithium bromide unit at time t; Q (t) represents the heat absorbed by the flue gas water type lithium bromide unit from the gas internal combustion engine at time t; K (i) represents the slope of the i-th segment of the efficiency line of the flue gas water type lithium bromide unit; L (t) represents the load rate of the flue gas water type lithium bromide unit; B (i) represents the intercept of the i-th segment of the efficiency line of the flue gas water type lithium bromide unit; and respectively represent the two end points of the i-th segment of the efficiency line of the flue gas water type lithium bromide unit;

[0028] For the centrifugal water chiller unit, its refrigeration load rate is obtained, and a model is constructed based on the refrigeration load rate, which is:

[0029] ,

[0030] ,

[0031] wherein, P (t) represents the refrigeration power of the centrifugal water chiller unit at time t; η (t) represents the refrigeration efficiency of the centrifugal water chiller unit at time t; Q (t) represents the electric power consumed by the centrifugal water chiller unit for refrigeration at time t; K (i) represents the slope of the i-th segment of the refrigeration line of the centrifugal water chiller unit; L (t) represents; B (i) represents the intercept of the i-th segment of the refrigeration line of the centrifugal water chiller unit; and respectively represent the two end points of the i-th segment of the refrigeration line of the centrifugal water chiller unit.

[0032] As a preferred technical solution, the method for modeling the energy transmission device is as follows:

[0033] ,

[0034] ,

[0035] ,

[0036] in, This represents the electrical power consumed by the energy transmission device at time t; This represents the mass flow rate through the water energy transmission device at time t; Represents gravitational acceleration; This represents the head of the energy transmission device at time t; This represents the efficiency of the energy transmission device at time t; Indicates the hot and cold power flowing into the energy transmission equipment; Indicates the time it takes for the solute to travel through the pipe; This indicates the specific heat capacity of the solute in the pipe; Indicates the inlet water temperature; Indicates the outlet water temperature; This represents the ratio of head efficiency, and ; This represents the slope of the i-th segment of the mass flow rate through the energy transmission device; This represents the intercept of the i-th segment of the mass flow rate through the energy transmission device; and This represents the two endpoints of the i-th segment of the mass flow rate through the energy transmission device.

[0037] As a preferred technical solution, the objective function includes the integrated energy system and grid interaction cost term and the integrated energy system gas purchase cost term.

[0038] The integrated energy system and grid interaction cost item mentioned above is:

[0039] ,

[0040] This represents the cost of interaction between the integrated energy system and the power grid; This represents the price at which the integrated energy system purchases electricity from the grid at time t; This indicates the amount of electricity the integrated energy system purchases from the grid; Indicates integrated energy system The price of electricity sold to the grid at all times; This represents the power output of the integrated energy system to the grid at time t.

[0041] As a preferred technical scheme, the gas purchase cost item of the comprehensive energy system is:

[0042] ,

[0043] ,

[0044] As a preferred technical scheme, the constraint includes:

[0045] The device operation constraint includes a device operation constraint item, a gas engine constraint item, a centrifugal water chiller unit, a flue gas hot water type lithium bromide unit state constraint item and a device startup priority constraint item, which are:

[0046] ,

[0047] ,

[0048] ,

[0049] ,

[0050] ,

[0051] , ​​​​​​​​​​​​​​​​​Pmax, flue gas hot water type lithium bromide unit P, i, dual working condition centrifugal water chiller Pmax, i, dual working condition centrifugal water chiller P, centrifugal water chiller Pmax, centrifugal water chiller P, t, single loop gas boiler Pmax, single loop gas boiler P, t, dual loop gas boiler Pmax, dual loop gas boiler P, t, dual loop gas boiler Pmax, dual loop gas boiler P, t, centrifugal water chiller Pmax, centrifugal water chiller m, t, water energy transmission device mmax, t, water energy transmission device P, off-peak electricity price period, gas internal combustion engine Pmax, off-peak electricity price period, gas internal combustion engine t, off-peak electricity price period ice making flag, t, centrifugal water chiller ice making safety threshold, dual working condition water chiller cooling flag, t, centrifugal water chiller cooling safety threshold, dual working condition water chiller cooling flag, flue gas hot water type lithium bromide unit cooling safety threshold, flue gas hot water type lithium bromide unit heating flag, flue gas hot water type lithium bromide unit heating safety threshold, flue gas hot water type lithium bromide unit P, z, t, k type device N, k type device

[0052] energy balance constraint, for:

[0053] ,

[0054] ,

[0055] ,

[0056] ,

[0057] ,

[0058] ,

[0059] wherein, represents the power supply of the photovoltaic device at time t; represents the electric power output by the gas internal combustion engine at time t; represents the power sold to the grid by the integrated energy system at time t; represents the refrigeration power of the centrifugal water chiller; represents the refrigeration power of the dual-working-condition centrifugal water chiller; represents the power of the i-th dual-working-condition centrifugal water chiller; represents the electric power consumed by the energy transmission device at time t; represents the heat production power of the boiler at time t; represents the gas consumption of the gas internal combustion engine at time t; represents the gas consumption of the single-loop gas boiler at time t; represents the total gas consumption of the dual-loop gas boiler at time t; represents the cold load at time t; represents the ice storage power of the ice storage coil at time t; represents the ice release power of the ice storage coil at time t; represents the low-temperature heat load at time t; represents the output power of the gas hot water boiler at time t; represents the high-temperature heat load at time t;

[0060] The energy storage device constraint is:

[0061] ,

[0062] ,

[0063] ,

[0064] ,

[0065] wherein, represents the capacity of the ice storage coil at time t; represents the energy storage loss rate of the ice storage coil; represents the ice storage efficiency of the ice storage coil; represents the ice release efficiency of the ice storage coil; represents the ice storage flag of the ice storage coil; an ice release flag of the ice storage coil; and a minimum value and a maximum value of the capacity of the ice storage coil; a capacity of the ice storage coil at time T, T representing the total working time of the ice storage coil; an initial capacity of the ice storage coil;

[0066] a pipeline flow balance constraint, which is that the cold and heat power of each pipeline in the integrated energy system before and after the pipeline is working is the same without loss;

[0067] an energy transmission device mass flow constraint, which is that the mass flow of the secondary side energy transmission device in the integrated energy system should satisfy , a mass flow required by the load at time t.

[0068] As a preferred technical solution, the method further comprises: performing optimization effect evaluation based on the optimal output strategy calculation with a unit energy consumption cost, and the calculation method of the unit energy consumption cost is:

[0069] .

[0070] As a preferred technical solution, the optimal output strategy is solved by using a Cplex algorithm.

[0071] According to a second aspect of the present application, an electronic device is provided, comprising a memory and a processor, the memory has a computer program stored thereon, and the processor implements the method when executing the program.

[0072] According to a third aspect of the present application, a computer readable storage medium is provided, which has a computer program stored thereon, and the program is executed by a processor to implement the method.

[0073] Compared with the prior art, the present application has the following beneficial effects:

[0074] 1) This invention uses an energy bus modeling approach to perform refined modeling of multiple devices of the same type, taking into account their varying operating conditions. Specifically, when constructing the models of each device in the integrated energy system, different operating conditions of the system are considered separately. In addition, to address the problem that existing technologies neglect the output of multiple devices of the same type when constructing integrated energy system models, leading to doubts about the rationality of scheduling strategies, this invention focuses on the output and dynamic characteristics of each device at different times. For example, the starting priority constraint of the same type of device is considered during the constraint construction process to avoid multiple devices of the same type switching and starting during optimization, which would cause frequent start-stop of the devices. This is beneficial for the reasonable allocation of the output of multiple devices of the same type, making the generated optimization strategy more reliable.

[0075] 2) This invention considers the variable operating conditions of energy transmission equipment and focuses on its dynamic characteristics. Based on the dynamic characteristics of mass flow rate in the energy transmission equipment, an electrical power loss model is constructed. Compared with the prior art which sets the operating conditions of energy transmission equipment to fixed conditions, this invention can better depict the flow balance relationship within the integrated energy system, which is beneficial to the rational use of energy, avoids the phenomenon of "overpowered power," and increases the stability of the system. Attached Figure Description

[0076] Figure 1 This is a flowchart of the method of the present invention;

[0077] Figure 2 This is a structural diagram of the integrated energy system of the present invention;

[0078] Figure 3 This is a diagram showing the load of the integrated energy system of the present invention on a typical winter day;

[0079] Figure 4 This is a diagram showing the load conditions of the integrated energy system of the present invention on a typical summer day;

[0080] Figure 5 This is a diagram showing the variation of the technical parameters of the integrated energy system energy conversion device of the present invention;

[0081] Figure 6 This is a frequency conversion characteristic diagram of the energy transmission device of the integrated energy system of the present invention;

[0082] Figure 7 This is a diagram showing the optimized operation results of the integrated energy system of the present invention in a typical summer day scenario 3.

[0083] Figure 8 The variable operating characteristic curve of the energy conversion equipment in summer scenario 3 of the integrated energy system of the present invention is shown.

[0084] Figure 9The energy transmission equipment variable operating frequency operation characteristic curve of the comprehensive energy system summer scene 3 of the application;

[0085] Figure 10 The winter cold load optimal dispatching result schematic diagram of the application;

[0086] Figure 11 The winter low-temperature heat load optimal dispatching result schematic diagram of the application;

[0087] Figure 12 The winter high-temperature heat load optimal dispatching result schematic diagram of the application;

[0088] Figure 13 The energy conversion equipment variable operating condition operation characteristic curve of the comprehensive energy system winter scene 3 of the application;

[0089] Figure 14 The energy transmission equipment variable operating frequency operation characteristic curve of the comprehensive energy system winter scene 3 of the application. DETAILED DESCRIPTION

[0090] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work should belong to the protection scope of the application.

[0091] Embodiment 1

[0092] In order to solve the problems in the prior art, the application provides a comprehensive energy system variable operating condition optimal regulation and control method considering equipment variable operating condition characteristics. Specifically, according to the output characteristics of each device, a comprehensive energy system containing cold-heat-power multi-energy coupling is constructed, the energy coupling relationship and operating characteristics of each device in the system, and the energy medium generation, conversion and use process are analyzed; according to the obtained energy conversion information, the variable operating condition characteristics of the device and the frequency characteristics of the energy transmission device are considered to establish a comprehensive energy system variable operating condition optimal regulation and control model with the lowest operating cost as the optimization target, and the energy supply reliability, the unique state of charge and discharge of the energy storage device, the flow balance and the like as the constraint conditions; finally, the CPLEX is used to solve the optimal output strategy of the comprehensive energy system, and the process is as shown in Figure 1 The process includes the following steps.

[0093] S1, for the comprehensive energy system, the energy coupling relationship and operating characteristics of each device in the system are analyzed, and the influence of the load rate of the comprehensive energy system on the efficiency of the energy conversion device is considered, the device and the energy transmission device are modeled, and the comprehensive energy system model is obtained, and in the modeling process, the energy bus modeling method is used to consider the variable operating condition characteristics of each device one by one.

[0094] In detail, the integrated energy system involved in this invention mainly consists of photovoltaic equipment, a gas-fired internal combustion engine GT, a flue gas hot water type lithium bromide unit LB, a gas-fired hot water boiler GB, a dual-condition centrifugal chiller unit DCWC, a centrifugal chiller unit EC, and an ice storage coil ISC, etc., and its structure is as follows. Figure 2 As shown, the functions of each device are as follows: (1) Renewable energy supply unit, namely photovoltaic equipment, which mainly utilizes the new concept of "building-integrated photovoltaics" to install photovoltaic power generation arrays on the outer surface of the building envelope to provide part of the electricity; (2) Refrigeration equipment, which consists of flue gas hot water type lithium bromide chiller unit and dual-condition centrifugal chiller unit. The flue gas hot water type lithium bromide chiller unit is connected to the gas internal combustion engine. It mainly uses the waste heat of flue gas and cylinder liner water generated by the gas internal combustion engine for refrigeration. The dual-condition centrifugal chiller unit mainly uses electricity for refrigeration; (3) Heating equipment, which consists of flue gas hot water type lithium bromide chiller unit and gas boiler. The flue gas hot water type lithium bromide chiller unit is connected to the gas internal combustion engine. It mainly uses the waste heat of flue gas and cylinder liner water generated by the gas internal combustion engine for refrigeration. The gas boiler uses gas for heating; (4) Energy storage equipment: which consists of dual-condition centrifugal chiller unit and ice storage coil, which plays the role of energy storage and regulation in the system. In the aforementioned equipment, the gas-fired internal combustion engine and the flue gas hot water type lithium bromide unit together constitute a combined cooling, heating, and power (CCHP) unit. Through the CCHP unit, gas can be converted into electrical energy, thermal energy, and cooling energy, realizing the coupling between different energy sources in the system.

[0095] Specifically, modeling of photovoltaic equipment, gas-fired internal combustion engines, gas-fired hot water boilers, flue gas hot water lithium bromide units, and centrifugal chillers includes:

[0096] For photovoltaic (PV) equipment, its output power, i.e., its power supply, is mainly related to the current light intensity and operating temperature. Therefore, by obtaining the light intensity and operating temperature of its operating environment, and constructing a model based on the light intensity and operating temperature, we can obtain the following:

[0097] ,

[0098] in, This represents the power supplied by photovoltaic device i at time t, in kW; This indicates the rated power of the photovoltaic equipment, in kW; The actual solar irradiance at time t in the environment where photovoltaic device i is located is expressed in units of . ; Indicates the intensity of the light being tested; This represents the temperature influence coefficient, which is taken as a value in this embodiment. ; This represents the actual photovoltaic operating temperature at time t in the environment where photovoltaic device i is located; This indicates the test operating temperature.

[0099] For gas-fired internal combustion engines, their power generation and heating efficiency are affected by many factors such as load rate, exhaust flow rate, exhaust temperature, temperature ratio, and ambient temperature. Among these, the load rate has the greatest impact. Therefore, this embodiment mainly considers the impact of the load rate on efficiency, obtains its electrical and thermal load rates, and constructs a model based on the electrical and thermal load rates as follows:

[0100] ,

[0101] ,

[0102] ,

[0103] ,

[0104] in, This represents the electrical power output of the gas-fired internal combustion engine at time t; This represents the actual power generation efficiency of the gas-fired internal combustion engine at time t. This represents the power output of the gas-fired internal combustion engine at time t; This represents the slope of the i-th segment of the line that generates electricity at time t using a gas-fired internal combustion engine. This represents the electrical load rate of the gas-fired internal combustion engine at time t; This represents the intercept of the i-th segment of the line that generates electricity at time t using a gas-fired internal combustion engine; and Let represent the two endpoints of the i-th segment of the power generation line of the gas internal combustion engine at time t; This represents the electrical power output of the gas-fired internal combustion engine at time t; This represents the actual heating efficiency of the gas-fired internal combustion engine at time t. The slope of the i-th segment of the heating line at time t of the gas-fired internal combustion engine is shown in the table. This represents the electrical load rate of the gas-fired internal combustion engine at time t; This represents the intercept of the i-th segment of the heating line provided by the gas-fired internal combustion engine at time t; and Let represent the two endpoints of the i-th segment of the heating line at time t of the gas-fired internal combustion engine.

[0105] For gas-fired hot water boilers, which use natural gas as fuel, the natural gas is burned inside the boiler to generate high-temperature gas for heating. Their heating efficiency is mainly affected by the load rate. The load rate is obtained during modeling, and a model is constructed based on the load rate, as follows:

[0106] ,

[0107] ,

[0108] wherein, represents the gas-fired hot water boiler output power at time t; represents the gas-fired hot water boiler efficiency at time t; represents the gas-fired hot water boiler natural gas power consumed at time t; represents the slope of the i-th segment of the gas-fired hot water boiler heating line; represents the load rate at time t; represents the intercept of the i-th segment of the gas-fired hot water boiler heating line; and represent the two end points of the i-th segment of the heating line, respectively.

[0109] For the flue gas hot water type lithium bromide unit, the energy efficiency ratio and the absorbed heat are nonlinearly related during heating and refrigeration, and the model is established as follows:

[0110] ,

[0111] ,

[0112] wherein, represents the flue gas hot water type lithium bromide unit power at time t; represents the flue gas hot water type lithium bromide unit efficiency at time t; represents the flue gas hot water type lithium bromide unit heat absorbed from the gas internal combustion engine at time t; represents the slope of the i-th segment of the flue gas hot water type lithium bromide unit efficiency line; represents the flue gas hot water type lithium bromide unit load rate; represents the intercept of the i-th segment of the flue gas hot water type lithium bromide unit efficiency line; and represent the two end points of the i-th segment of the flue gas hot water type lithium bromide unit efficiency line, respectively.

[0113] For the centrifugal water chiller unit, its COP (energy efficiency ratio) is mainly related to the load rate, and the refrigeration load rate is obtained, and the model is constructed based on the refrigeration load rate, which is:

[0114] ,

[0115] ,

[0116] wherein, represents the centrifugal water chiller unit refrigeration power at time t; represents the centrifugal water chiller unit refrigeration efficiency at time t; represents the centrifugal water chiller unit refrigeration power consumed at time t; represents the slope of the i-th segment of the centrifugal water chiller unit refrigeration line; represents; represents the intercept of the i-th segment of the refrigeration line of the centrifugal water chiller unit; and represents the two endpoints of the i-th segment of the refrigeration line of the centrifugal water chiller unit.

[0117] For the energy transmission equipment in the integrated energy system, considering its variable frequency characteristics, when the flow through the pipeline changes, the water pressure in the pipeline also changes, considering the influence of these factors on the frequency of the energy transmission equipment, and considering the influence of the load rate on the efficiency of the energy conversion equipment, a fine modeling is carried out, including:

[0118] ,

[0119] ,

[0120] ,

[0121] wherein, represents the electric power consumed by the energy transmission equipment at time t; represents the mass flow rate through the water energy transmission equipment at time t; represents the gravitational acceleration; represents the water head of the energy transmission equipment at time t; represents the efficiency of the energy transmission equipment at time t; represents the cold and heat power flowing into the energy transmission equipment; represents the time of the solute passing through the pipeline; represents the specific heat capacity of the solute in the pipeline; represents the inlet water temperature; represents the outlet water temperature; represents the lift efficiency ratio, and ; represents the slope of the i-th segment line of the mass flow rate through the energy transmission equipment; represents the intercept of the i-th segment line of the mass flow rate through the energy transmission equipment; and represents the two endpoints of the i-th segment line of the mass flow rate through the energy transmission equipment.

[0122] S2, based on the integrated energy system model, taking the minimum cost of the integrated energy system as the objective function and constructing constraints.

[0123] S21, objective function construction.

[0124] In this embodiment, an integrated energy system variable condition optimization control model is established, which takes the minimum cost as the objective function, and the equipment operating state, the equipment maximum capacity, the equipment switch state uniqueness, the cold and heat power balance, the pipeline flow rate, etc. as constraint conditions, which are as follows:

[0125] For the objective function, the cost in the integrated energy system mainly includes an integrated energy system and grid interaction cost term and an integrated energy system gas purchase cost term , expressed as: .

[0126] For the integrated energy system and grid interaction cost term, there is:

[0127] ,

[0128] denotes the integrated energy system and grid interaction cost term; denotes the integrated energy system t-time grid purchase electricity price; denotes the integrated energy system grid purchase power; denotes the integrated energy system time grid sale electricity price; denotes the integrated energy system t-time grid sale power.

[0129] For the integrated energy system gas purchase cost term, there is:

[0130] ,

[0131] wherein, denotes the integrated energy system gas purchase cost term; denotes the natural gas price; denotes the total gas consumption at t time; denotes the single loop gas hot water boiler heat output at t time; denotes the double gas hot water boiler high temperature heat output at t time; denotes the double loop gas hot water boiler low temperature heat output at t time; denotes the gas internal combustion engine heat output at t time; denotes the single loop gas boiler heat efficiency at t time; denotes the natural gas calorific value; denotes the double loop gas boiler high temperature heat efficiency at t time; double loop gas boiler low temperature heat efficiency at t time; denotes the gas internal combustion engine heat efficiency at t time.

[0132] S22, constraint construction.

[0133] In the present application, the constructed constraints include device operation constraints, energy balance constraints, energy storage device constraints, pipe flow balance constraints, and energy transmission device mass flow constraints.

[0134] a) Device operation constraints:

[0135] In the embodiment, the device operation constraints include a device operation constraint term, a gas internal combustion engine constraint term, a centrifugal water chiller, a flue gas hot water type lithium bromide chiller state constraint term, and a device startup priority constraint term. In detail, the device operation constraint term is that the device is subject to its own capacity constraint in the optimization operation, and part of the device is also subject to a safe operation threshold constraint, as shown in formula (1); the gas internal combustion engine constraint term is to constrain the gas internal combustion engine from starting during the off-peak electricity price period, so as to meet the engineering actual situation, as shown in formula (2); the centrifugal water chiller, the flue gas hot water type lithium bromide chiller state constraint term is a constraint made because the dual-working-condition centrifugal water chiller and the flue gas hot water type lithium bromide chiller have two working states and cannot be in two different working conditions at the same time, as shown in formula (3)-(4); and the device startup priority constraint term is to set the startup priority constraint of the same type of device to avoid switching startup during optimization and cause frequent start-stop of the device, as shown in formula (5).

[0136] (1)

[0137] (2)

[0138] (3)

[0139] (4)

[0140] (5)

[0141] wherein, represents the total power output by the gas internal combustion engine at time t; represents the maximum value of the total power output by the gas internal combustion engine at time t; represents the refrigeration power of the flue gas hot water type lithium bromide chiller; represents the maximum value of the refrigeration power of the flue gas hot water type lithium bromide chiller; represents the heating power of the flue gas hot water type lithium bromide chiller; represents the maximum value of the heating power of the flue gas hot water type lithium bromide chiller; represents the power of the i th dual-working-condition centrifugal water chiller; represents the maximum value of the power of the i th dual-working-condition centrifugal water chiller; represents the refrigeration power of the centrifugal water chiller; represents the maximum value of the refrigeration power of the centrifugal water chiller; represents the heating power of the single-loop gas boiler at time t; represents the maximum heating power of the single-loop gas boiler; represents the low-temperature heating power of the dual-circuit gas-fired boiler at time t; represents the maximum value of the low-temperature heating power of the dual-circuit gas-fired boiler; represents the high-temperature heating power of the dual-circuit gas-fired boiler at time t; represents the maximum value of the low-temperature heating power of the dual-circuit gas-fired boiler; represents the refrigeration power of the centrifugal cold water unit at time t; represents the maximum value of the refrigeration power of the centrifugal cold water unit; represents the mass flow rate through the water energy transmission device at time t; represents the maximum value of the mass flow rate through the water energy transmission device at time t; represents the power of the gas internal combustion engine during the off-peak electricity price period; and represents the start and end time of the off-peak electricity price period; represents the ice-making flag of the centrifugal cold water unit at time t; represents the ice-making safety threshold of the dual-mode cold water unit; represents the refrigeration flag of the centrifugal cold water unit at time t; represents the refrigeration safety threshold of the dual-mode cold water unit; represents the refrigeration flag of the flue gas hot water type lithium bromide unit; represents the refrigeration safety threshold of the flue gas hot water type lithium bromide unit; represents the heating flag of the flue gas hot water type lithium bromide unit; represents the heating safety threshold of the flue gas hot water type lithium bromide unit; represents the power of the zth device of the kth type at time t; represents the total number of devices of the kth type.

[0142] b) Energy balance constraints:

[0143] To ensure that the system can stably supply energy, energy balance constraints need to be established between each device and load, which are:

[0144] ,

[0145] ,

[0146] ,

[0147] ,

[0148] ,

[0149] ,

[0150] wherein, represents the power supply of the photovoltaic device at time t; represents the electric power output by the gas internal combustion engine at time t; represents the power sold to the grid by the integrated energy system at time t; represents the refrigeration power of the centrifugal water chiller; represents the refrigeration power of the dual-working-condition centrifugal water chiller; represents the power of the i-th dual-working-condition centrifugal water chiller; represents the electric power consumed by the energy transmission device at time t; represents the heat production power of the boiler at time t; represents the gas consumption of the gas internal combustion engine at time t; represents the gas consumption of the single-loop gas boiler at time t; represents the total gas consumption of the dual-loop gas boiler at time t; represents the cooling load at time t; represents the ice storage power of the ice storage coil at time t; represents the ice release power of the ice storage coil at time t; represents the low-temperature heat load at time t; represents the output power of the gas hot water boiler at time t; represents the high-temperature heat load at time t.

[0151] c) Energy storage device constraints:

[0152] The energy storage device is subject to many conditions during operation. First, the capacity constraint, the total amount of energy that the energy storage device can store is determined by its capacity, and in the optimization operation, the storage capacity should be reasonably managed and utilized to avoid the system from being unstable due to the storage exceeding the range. Second, the energy storage device is subject to the charging and discharging power constraints, and the charging and discharging rates need to be adjusted according to the actual load and energy supply and demand. In addition, in order to avoid the energy storage device from charging and discharging at the same time, a charging and discharging flag needs to be set. In addition, the energy storage device needs to maintain energy conservation during the storage and release of energy, and energy compensation and adjustment are needed to achieve energy conservation. In addition, energy loss needs to be considered. The specific constraints are:

[0153] ,

[0154] ,

[0155] ,

[0156] ,

[0157] wherein, represents the capacity of the ice storage coil at time t; represents the energy storage loss rate of the ice storage coil. represents the ice storage efficiency of the ice storage coil; represents the ice release efficiency of the ice storage coil; represents the ice storage flag of the ice storage coil; represents the ice release flag of the ice storage coil; and represent the minimum and maximum values of the capacity of the ice storage coil; represents the capacity of the ice storage coil at time T, and T represents the total working time of the ice storage coil; represents the initial capacity of the ice storage coil.

[0158] d) a pipeline flow balance constraint, which is that the cold and heat powers of each pipeline in the integrated energy system before and after the pipeline is working are the same and there is no loss, i.e. , and represent the cold and heat powers of the pipeline before and after working, respectively.

[0159] e) an energy transmission device mass flow constraint, which is that the mass flow of the energy transmission device on the secondary side in the integrated energy system should satisfy , represents the mass flow required by the load at time t.

[0160] S3, based on the objective function and the constraints, solving the optimal output strategy of the integrated energy system.

[0161] In the present application, the optimal output strategy is solved by using the mixed integer linear programming theory and the Cplex algorithm, and the process is a conventional technical means in the field, and thus is not described in detail.

[0162] In addition, after the optimal output strategy is generated, the unit energy consumption cost is also calculated based on the optimal output strategy for the optimization effect evaluation, and the calculation method of the unit energy consumption cost is:

[0163] .

[0164] The above is the method for the variable working condition optimization and regulation of the integrated energy system considering the variable working condition characteristics provided by the present application.

[0165] Embodiment 2

[0166] In this embodiment, the method provided by the present application is used to optimize and schedule a certain integrated energy system, the winter typical day load information of the integrated energy system is as shown in Figure 3 , the summer typical day load information is as shown in Figure 4 , the energy conversion device technical parameters are as shown in Figure 5 , and the following three scenes are set for the system to compare the rationality and effectiveness of the method:

[0167] Scenario 1: considering the constant efficiency operation characteristics of multiple energy conversion devices and the energy consumption of the constant frequency operation of the energy transmission device.

[0168] Scenario 2: considering the variable operating condition characteristics of multiple energy conversion devices and the energy consumption of the constant frequency operation of the energy transmission device.

[0169] Scenario 3 (the method provided by the present application): considering the variable operating condition characteristics of multiple energy conversion devices and the energy consumption of the variable frequency operation of the energy transmission device.

[0170] The optimal scheduling strategy is generated for the above three scenarios in summer and winter, respectively.

[0171] I) Summer.

[0172] The optimal scheduling strategy is generated for the above three scenarios, and the running cost and unit energy consumption cost data of the optimal scheduling strategy of the three scenarios in a typical summer day are collected, as shown in Table 1.

[0173] Table 1: Running cost and unit energy consumption cost data table of three scenarios in summer

[0174]

[0175] From Table 1, the running cost from high to low in summer is scenario 1, 2, 3, which is due to the constant efficiency operation of the energy conversion device in scenario 1, and the optimization does not consider the existence of the best operating condition of the device. Figure 5 It can be seen that the COP curve of the refrigeration device is a convex curve, and the middle is the best operating condition of the refrigeration device. From Table 1, the COP values of the constant operating condition of the refrigeration device are not the best operating condition point of the device, for example, the COP of the centrifugal water chiller C-type is 5.4 at 100% load and 5.528 at 90% load, and the COP value decreases, resulting in additional costs and energy waste in the optimization scheme of this scenario.

[0176] Compared with scenario 1, scenario 2 uses device variable operating condition nonlinear modeling, and the daily running cost is significantly reduced, and the device can effectively operate near the best operating condition point, but the energy consumption of the energy transmission device increases by 0.4% compared with scenario 1, because the device operates near the best operating condition point, the energy consumption of the device is reduced, but the energy transmission device operates at a constant frequency, and the head efficiency ratio of the energy transmission device is a constant value, and the frequency does not change with the change of the flow value through the energy transmission device, which is a "horse pulling a cart" energy waste phenomenon, and the constant frequency operation mode of the energy transmission device does not match the variable operating condition operation of the device.

[0177] Compared to the variable frequency operation of the energy transmission equipment in scenarios 2 and 3, the following diagram is drawn for scenario 3: Figure 6 The graph shown illustrates the variation of technical parameters of the energy transfer equipment. The frequency of the energy transfer equipment changes with the mass flow rate, and its head efficiency is shown in the graph. Figure 6 ,Depend on Figure 6 It can be seen that its head efficiency ratio is directly proportional to the mass flow rate. When the equipment is at its optimal operating point, the mass flow rate decreases, the frequency of the energy transmission equipment decreases, and the power consumption also decreases. The frequency of the energy transmission equipment is adapted to the changing operating conditions of the equipment, and there will be no energy waste phenomenon similar to that in scenario 1 and scenario 2.

[0178] Plot the optimized operation results of Scenario 3 in summer and the operating characteristic curves of the energy transmission equipment under the optimal strategy, such as... Figure 7 , Figure 8 and Figure 9 As shown, due to the influence of time-of-use electricity pricing and natural gas prices, gas-fired internal combustion engines only operate during peak and off-peak electricity periods. Ice storage coils complete energy storage during off-peak hours when electricity prices are lowest and release energy during peak and off-peak periods, thereby reducing energy costs. Figure 8 It is known that centrifugal chillers and dual-condition centrifugal chillers will work together with ice storage coils to maintain themselves in a high COP state, thereby ensuring the economic efficiency of system operation and reducing energy waste.

[0179] Depend on Figure 9 It is known that when the equipment is operating at its optimal condition, the state of the variable frequency energy transfer equipment will change with the change in equipment output, so that the output state of the energy transfer equipment can be adapted to it. For example, during the period from 16:00 to 18:00, the output of the ice storage coil increases, and the head efficiency ratio of the chilled water circulation energy transfer equipment connected to it gradually increases from a small value, rather than remaining at its maximum value as it does when operating at a fixed frequency. Figure 8 and Figure 9 It can be seen that variable frequency operation of energy transmission equipment can save more energy than fixed frequency operation because when the equipment is operating under different conditions, its optimal operating point is not the maximum output point. If the operating frequency of the energy transmission equipment is the same as the frequency at the maximum output point of the equipment, it will inevitably lead to energy waste.

[0180] II. Winter.

[0181] The optimal scheduling strategy was generated for the three scenarios mentioned above, and the operating cost and unit energy consumption cost of the optimal scheduling strategy for the three scenarios on a typical winter day were collected. The operating cost and unit energy consumption cost data are shown in Table 2.

[0182] Table 2. Operating Costs and Unit Energy Consumption Costs for Three Winter Scenarios

[0183]

[0184] From Table 2, the winter operation cost from high to low is scenario 1, 2, 3; the high and low order of operation cost of Table 1 and Table 2 is the same, the reason why scenario 1 is expensive in winter is the same as in summer-the equipment cannot be in the best operating point, causing waste of energy, scenario 2 uses variable operating condition nonlinear modeling, the equipment can be in the best operating point, the operation cost is significantly reduced, but the electricity sales are reduced, because the electric efficiency of the gas internal combustion engine is the maximum value in the fixed operating condition, and when the variable operating condition is operated, the electric efficiency value is reduced, so the power generation is reduced; in the case of reduced winter electricity equipment, the energy transmission equipment power consumption becomes the main power consumption of the system, and the energy transmission equipment power consumption accounts for more than half; in scenario 3, the energy transmission equipment adopts variable frequency operation to effectively reduce the operation cost and power consumption, so it can be seen that when the energy conversion equipment is less, the energy transmission equipment energy-saving operation is particularly important.

[0185] Draw the optimization operation result of scenario 3 in winter Figures 10-12 , the variable operating condition characteristic curve of the energy conversion equipment Figure 13 , and the variable operating condition characteristic curve of the energy transmission equipment Figure 14 , wherein Figure 10 represents the winter cold load optimization scheduling result schematic diagram, Figure 11 represents the winter low-temperature heat load optimization scheduling result schematic diagram, Figure 12 represents the winter high-temperature heat load optimization scheduling result schematic diagram, it can be seen that under the influence of time-of-use electricity price and natural gas price, the gas internal combustion engine only operates in the peak electricity price period, because the cold load is low and the refrigeration efficiency of the lithium bromide unit is lower than the heating efficiency, the unit cannot operate at the best operating point, so the combined heat and power system composed of the gas internal combustion engine and the lithium bromide unit is always in the heating operating condition. When the cold load is low, the dual-condition water chiller unit combined with the ice storage disc tube cooling makes the unit also close to the optimal operating condition to the greatest extent at low load, when the low-temperature heat load is met, the single-loop boiler and the double-loop boiler have the same variable operating condition characteristics, but their device capacities are different, and their output values at the best operating point are different, the single-loop boiler combined with the double-loop boiler low-temperature heating can make both of them operate near the best operating point at the current load, the variable operating condition characteristic curves of the two are the same, but the low-temperature heating capacity of the double-loop boiler is smaller, that is, the output of the best operating point is smaller than that of the single-loop boiler, so the linkage of the two can stably operate near the best operating point. The flow of HWP_1 is greater than that of HWP_2 connected in parallel, which means that HWP_1 consumes less energy when the same flow passes through, so HWP_1 starts before HWP_2, and when the output of the energy conversion equipment connected thereto increases, HWP_2 starts. Compared with winter and summer, when the output of the dual-condition water chiller unit is significantly reduced in winter, the head efficiency of the energy transmission equipment group matched therewith is significantly reduced, avoiding waste of electric energy.

[0186] In summary, scenario 3, i.e., the method provided by the present application, performs excellently in both summer and winter compared with scenario 1 and scenario 2, i.e., the method provided by the present application has implementability and superiority.

[0187] Example 3

[0188] The present application also provides an electronic device for comprehensive energy system optimization scheduling, which comprises a central processing unit (CPU) that can perform various appropriate actions and processes according to computer program instructions stored in a read-only memory (ROM) or loaded into a random access memory (RAM) from a storage unit. In the RAM, various programs and data required for device operation can also be stored. The CPU, the ROM, and the RAM are connected to each other through a bus. An input / output (I / O) interface is also connected to the bus.

[0189] A plurality of components in the device are connected to the I / O interface, including: an input unit, such as a keyboard, a mouse, etc.; an output unit, such as various types of displays, speakers, etc.; a storage unit, such as a magnetic disk, an optical disk, etc.; and a communication unit, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit allows the device to exchange information / data with other devices through a computer network, such as the Internet, and / or various telecommunications networks.

[0190] The processing unit performs various methods and processes described above, such as methods S1-S3. For example, in some embodiments, methods S1-S3 can be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as the storage unit. In some embodiments, part or all of the computer program can be loaded and / or installed on the device via the ROM and / or the communication unit. When the computer program is loaded into the RAM and executed by the CPU, one or more steps of methods S1-S3 described above can be performed. Alternatively, in other embodiments, the CPU can be configured to perform methods S1-S3 by any other appropriate means (e.g., by means of firmware).

[0191] The functions described above in this document can be performed, at least in part, by one or more hardware logic components. For example, and without limitation, exemplary types of hardware logic components that can be used include: field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip systems (SOCs), complex programmable logic devices (CPLDs), etc.

[0192] Program code for carrying out methods of the present application can be written in any combination of one or more programming languages. This program code can be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the program code, when executed by the processor or controller, produces a means for implementing the functions / operations specified in the flowchart diagrams and / or block diagrams. The program code can be executed entirely on a machine, partially on a machine, partially on a machine as a stand-alone software package, or entirely on a remote machine or server.

[0193] In the context of the present application, a machine-readable medium can be a tangible medium that can contain or store program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable storage medium can include, but are not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the machine-readable storage medium will include one or more lines of electrical connections, portable computer disks, hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or Flash memory), optical fibers, portable compact disc read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination of the foregoing.

[0194] The above descriptions are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present application, and these modifications or replacements should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for optimizing and controlling a comprehensive energy system under varying operating conditions, characterized in that, The methods include: For integrated energy systems, the energy coupling relationships and operating characteristics of each device in the system are analyzed, and the impact of the load rate of the integrated energy system on the efficiency of energy conversion equipment is considered. The devices are modeled to obtain the integrated energy system model. In the modeling process, the energy bus modeling method is used to consider the variable operating conditions of multiple identical devices one by one. Based on the aforementioned integrated energy system model, the objective function is to minimize the integrated energy system cost, and constraints are constructed accordingly. Based on the objective function and constraints described above, the optimal power output strategy of the integrated energy system is solved. The equipment includes photovoltaic equipment, gas-fired internal combustion engines, gas-fired hot water boilers, flue gas hot water lithium bromide units, and centrifugal chillers. The modeling methods include: For the photovoltaic device, the light intensity and operating temperature of its working environment are obtained, and a model is constructed based on the light intensity and operating temperature as follows: ， in, This represents the power output of photovoltaic device i at time t; Indicates the rated power of the photovoltaic equipment; This represents the actual light intensity at time t in the environment where photovoltaic device i is located; Indicates the intensity of the light being tested; Indicates the temperature effect coefficient; This represents the actual photovoltaic operating temperature at time t in the environment where photovoltaic device i is located; Indicates the test operating temperature; For the aforementioned gas-fired internal combustion engine, its electrical and thermal load rates are obtained, and a model is constructed based on these electrical and thermal load rates as follows: ， ， ， ， in, This represents the electrical power output of the gas-fired internal combustion engine at time t; This represents the actual power generation efficiency of the gas-fired internal combustion engine at time t. This represents the power output of the gas-fired internal combustion engine at time t; This represents the slope of the i-th segment of the line that generates electricity at time t using a gas-fired internal combustion engine. This represents the electrical load rate of the gas-fired internal combustion engine at time t; This represents the intercept of the i-th segment of the line that generates electricity at time t using a gas-fired internal combustion engine; and Let represent the two endpoints of the i-th segment of the power generation line of the gas internal combustion engine at time t; This represents the electrical power output of the gas-fired internal combustion engine at time t; This represents the actual heating efficiency of the gas-fired internal combustion engine at time t. The slope of the i-th segment of the heating line at time t of the gas-fired internal combustion engine is shown in the table. This represents the electrical load rate of the gas-fired internal combustion engine at time t; This represents the intercept of the i-th segment of the heating line provided by the gas-fired internal combustion engine at time t; and Let represent the two endpoints of the i-th segment of the heating line of the gas internal combustion engine at time t; For the aforementioned gas-fired hot water boiler, its load rate is obtained, and a model is constructed based on the load rate as follows: ， ， in, This represents the output power of the gas-fired hot water boiler at time t; This represents the efficiency of the gas-fired hot water boiler at time t. This represents the power consumption of natural gas by the gas-fired hot water boiler at time t; This represents the slope of the i-th segment of the line used for heating by a gas-fired hot water boiler. This represents the load factor at time t; This represents the intercept of the i-th segment of the heating line supplied by the gas-fired hot water boiler. and These represent the two endpoints of the i-th segment of the heating line; For the aforementioned flue gas hot water type lithium bromide unit, the model is established as follows: ， ， in, This represents the power output of the flue gas hot water type lithium bromide turbine unit at time t; This represents the efficiency of the flue gas hot water type lithium bromide unit at time t; This represents the amount of heat absorbed by the gas-fired internal combustion engine in the flue gas hot water type lithium bromide turbine unit at time t. This represents the slope of the efficiency line of the i-th segment of a flue gas hot water type lithium bromide generator unit; This indicates the load rate of the flue gas hot water type lithium bromide unit; This represents the intercept of the efficiency line of the i-th segment of a flue gas hot water type lithium bromide generator unit. and These represent the two endpoints of the efficiency line of the i-th segment of the flue gas hot water type lithium bromide generator unit; For the centrifugal chiller unit, its cooling load rate is obtained, and a model is constructed based on the cooling load rate as follows: ， ， in, This represents the cooling power of the centrifugal chiller unit at time t; This represents the refrigeration efficiency of the centrifugal chiller unit at time t. This represents the electrical power consumed by the centrifugal chiller unit for cooling at time t; This represents the slope of the i-th segment of the refrigeration line in a centrifugal chiller unit. express; This represents the intercept of the i-th segment of the refrigeration line in a centrifugal chiller unit. and This represents the two ends of the i-th segment of the refrigeration line in a centrifugal chiller unit.

2. The method for optimizing and controlling a comprehensive energy system under varying operating conditions according to claim 1, characterized in that, The device also includes an energy transmission device, and the method for modeling the energy transmission device is as follows: ， ， ， in, This represents the electrical power consumed by the energy transmission device at time t; This represents the mass flow rate through the water energy transmission device at time t; Represents gravitational acceleration; This represents the head of the energy transmission device at time t; This represents the efficiency of the energy transmission device at time t; Indicates the hot and cold power flowing into the energy transmission equipment; Indicates the time it takes for the solute to travel through the pipe; This indicates the specific heat capacity of the solute in the pipe; Indicates the inlet water temperature; Indicates the outlet water temperature; This represents the ratio of head efficiency, and ; This represents the slope of the i-th segment of the mass flow rate through the energy transmission device; This represents the intercept of the i-th segment of the mass flow rate through the energy transmission device; and This represents the two endpoints of the i-th segment of the mass flow rate through the energy transmission device.

3. The method for optimizing and controlling a comprehensive energy system under varying operating conditions according to claim 1, characterized in that, The objective function includes the integrated energy system and grid interaction cost term and the integrated energy system gas purchase cost term. The integrated energy system and grid interaction cost item mentioned above is: ， This represents the cost of interaction between the integrated energy system and the power grid; This represents the price at which the integrated energy system purchases electricity from the grid at time t; This indicates the amount of electricity the integrated energy system purchases from the grid; Indicates integrated energy system The price of electricity sold to the grid at all times; This represents the power output of the integrated energy system to the grid at time t.

4. The method for optimizing and controlling a comprehensive energy system under varying operating conditions according to claim 3, characterized in that, The gas purchase cost item of the integrated energy system is as follows: ， in, This represents the gas purchase cost item of the integrated energy system; Indicates the price of natural gas; This is expressed as the total gas consumption at time t; This represents the heat output of a single-loop gas-fired hot water boiler at time t. This indicates the high-temperature heat output of the dual-gas-fired hot water boiler at time t; This indicates the low-temperature heat output of the dual-loop gas-fired hot water boiler at time t. This represents the heat output of the gas-fired internal combustion engine at time t; This represents the heat production efficiency of a single-loop gas-fired boiler at time t. Indicates the calorific value of natural gas; This represents the high-temperature heat production efficiency of the dual-loop gas-fired boiler at time t. Low-temperature heat production efficiency of dual-loop gas-fired boilers; This indicates the heat production efficiency of a gas-fired internal combustion engine at any given time.

5. The method for optimizing and controlling a comprehensive energy system under varying operating conditions according to claim 1, characterized in that, The constraints include: Equipment operation constraints, including equipment operation constraints, gas internal combustion engine constraints, centrifugal chiller unit, flue gas hot water type lithium bromide unit status constraints, and equipment start-up priority constraints, are as follows: ， ， ， ， ， in, This represents the total power output of the gas internal combustion engine at time t; This represents the maximum total power output of the gas-fired internal combustion engine at time t; Indicates the cooling capacity of the flue gas hot water type lithium bromide unit; This indicates the maximum cooling capacity of the flue gas hot water type lithium bromide unit; This indicates the heating capacity of the flue gas hot water type lithium bromide unit. This indicates the maximum heating power of the flue gas hot water type lithium bromide unit; This represents the power of the i-th dual-condition centrifugal chiller unit; This represents the maximum power of the i-th dual-condition centrifugal chiller unit; This indicates the cooling capacity of the centrifugal chiller unit; This indicates the maximum cooling capacity of the centrifugal chiller unit; This represents the heating power of a single-loop gas-fired boiler at time t. This indicates the maximum heating capacity of a single-loop gas-fired boiler; This represents the low-temperature heating power of a dual-loop gas-fired boiler at time t. This indicates the maximum low-temperature heating power of a dual-loop gas-fired boiler; This represents the high-temperature heating power of a dual-loop gas-fired boiler at time t. This indicates the maximum value of the low-temperature heating power of the dual-circuit gas boiler; This represents the cooling capacity of the centrifugal chiller unit at time t. This indicates the maximum cooling capacity of the centrifugal chiller unit; This represents the mass flow rate through the water energy transmission device at time t; This represents the maximum mass flow rate through the water energy transmission device at time t; This indicates the power output of a gas-fired internal combustion engine during off-peak electricity pricing periods. and Indicates the start and end times of the off-peak electricity pricing period; This indicates the ice-making flag of the centrifugal chiller unit at time t; This indicates the ice-making safety threshold for dual-condition chillers; This indicates the refrigeration flag of the centrifugal chiller unit at time t; This indicates the refrigeration safety threshold for dual-condition chillers; This indicates the refrigeration flag for flue gas hot water type lithium bromide chillers; This indicates the refrigeration safety threshold for flue gas hot water type lithium bromide chillers; This indicates the heating indicator for a flue gas hot water type lithium bromide chiller unit; This indicates the heating safety threshold for gas-fired hot water type lithium bromide units; This represents the power of the device at time t in the z-th time group k; This represents the total number of devices in category k; The energy balance constraint is: ， ， ， ， ， ， in, This represents the power output of the photovoltaic device at time t; This represents the electrical power output of the gas-fired internal combustion engine at time t; This represents the total power output of the integrated energy system sold to the grid at time t; This indicates the cooling capacity of the centrifugal chiller unit; This indicates the cooling capacity of the dual-condition centrifugal chiller unit; This represents the power of the i-th dual-condition centrifugal chiller unit; This represents the electrical power consumed by the energy transmission device at time t; This represents the boiler's heat output at time t; This represents the gas consumption of a gas-fired internal combustion engine at time t. This represents the gas consumption of a single-loop gas-fired boiler at time t. This represents the total gas consumption of a dual-loop gas-fired boiler at time t. This represents the cooling load at time t; This represents the ice storage capacity of the ice storage coil at time t; This represents the ice release power of the ice storage coil at time t; This represents the low-temperature heat load at time t; This represents the output power of the gas-fired hot water boiler at time t; This represents the high-temperature heat load at time t; The constraints on energy storage devices are: ， ， ， ， in, This represents the capacity of the ice storage coil at time t; This indicates the energy storage loss rate of the ice storage coil; This indicates the ice storage efficiency of the ice storage coil; This indicates the ice release efficiency of the ice storage coil; This indicates the ice storage flag of the ice storage coil; This indicates the ice release flag of the ice storage coil; and This indicates the minimum and maximum capacity of the ice storage coil; This represents the capacity of the ice storage coil at time T, where T represents the total working time of the ice storage coil. Indicates the initial capacity of the ice storage coil; The pipeline flow balance constraint is: in the integrated energy system, the cooling and heating power of each pipeline is the same before and after it is in operation, and there is no loss. The mass flow rate constraint for energy transmission equipment is defined as the requirement that the mass flow rate of secondary-side energy transmission equipment in the integrated energy system must meet certain conditions. , This represents the mass flow rate required for the load at time t.

6. The method for optimizing and controlling a comprehensive energy system under varying operating conditions according to claim 1, characterized in that, The method further includes evaluating the optimization effect based on the optimal output strategy, using a unit energy cost calculation method, wherein the unit energy cost calculation method is as follows: 。 7. The method for optimizing and controlling a comprehensive energy system under varying operating conditions according to claim 1, characterized in that, The optimal output strategy described above is solved using the Cplex algorithm.

8. An electronic device for optimizing and controlling the variable operating conditions of an integrated energy system, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the program, it implements the method as described in any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1 to 7.

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