Method, system, device and medium for optimizing cold storage and heat storage load participation in ramp market

Abstract

The application belongs to the technical field of power system and energy management, and discloses a method, system, device and medium for optimization of cold storage and heat storage load participating in climbing market, which comprises the following steps: through scheduling of heat source units and water storage tanks, a target function of economic benefits of cold storage and heat storage load participating in climbing market is established; and according to the target function of economic benefits of cold storage and heat storage load participating in climbing market, a constraint condition of energy optimization of the power system is established; and according to the target function of economic benefits of cold storage and heat storage load participating in climbing market and the constraint condition of energy optimization of the power system, a solver is used to solve the load scheduling of the power system to obtain an optimal load scheduling scheme of the power system. The application can obtain higher economic benefits while meeting the demand of power grid regulation, promote the low-carbon development of the power system, and provide a practical reference scheme for energy system planning and construction.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power systems and energy management, and particularly relates to a method, system, device and medium for an ice storage load participating in a ramping market optimization. BACKGROUND

[0002] Ice storage load, represented by air source heat pump, has good ice storage characteristics and can play a role in continuous regulation to meet system ramping demand. At present, ice storage load is growing explosively, and its proportion in cold and heat load will reach more than 20% in the future. If it is included in the regulation system, it will significantly improve the ability of the power grid to meet the demand for ramping, peak shaving and other needs. At present, the technical form of how the main body of such load can support system ramping demand is not clear, which is reflected in the following aspects: the ice storage load model is not accurate enough, the flexible ramping capacity evaluation index is not complete enough, and the ramping control strategy has not been established.

[0003] Demand side response is one of the important means for modern power systems to achieve supply and demand balance. Through reasonable regulation on the load side, demand side response not only can reduce peak load and improve energy utilization efficiency, but also can respond to changes in the power system by dynamically adjusting demand, thereby improving the stability of the power grid. With the popularity of renewable energy, the power system is facing more volatility and uncertainty, and the ramping market has become an important market mechanism to encourage system resources to provide rapid power adjustment capability. Ice storage load in demand side response has flexible regulation capability and can provide effective load response in the context of ramping up and ramping down, so it has great potential to participate in the ramping market and obtain economic benefits.

[0004] The development of power market economics has fundamentally changed the operation mode of the power system. Load is no longer a passive consumer, but can maximize economic benefits by participating in the market. Under such a background, ice storage load has broad application prospects: by participating in the ramping market, it can not only maintain the balance between supply and demand of the power grid in the case of large load fluctuations, but also can obtain economic benefits by appropriately reducing or increasing power consumption during the peak period of market prices. However, there are still many deficiencies in the current research on how ice storage load can effectively participate in the ramping market, including the accuracy of the load model, the quantitative evaluation of the flexible ramping capacity, and the optimal control strategy for market demand has not been fully established.

[0005] Therefore, how to provide a method, system, device and medium for ice storage load participating in a ramping market optimization is a problem to be solved at present. SUMMARY

[0006] The embodiments of the present application provide a method, system, device and medium for ice storage load participating in a ramping market optimization to solve the problem that the ice storage load cannot effectively participate in the ramping market in the prior art.

[0007] The following presents a simplified summary of some aspects of the disclosed embodiments in order to provide a basic understanding of such embodiments. This summary is not an extensive overview of the embodiments and is intended neither to identify key / critical elements of the embodiments nor to delineate the scope of the embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

[0008] According to a first aspect of the embodiments of the present application, there is provided a method for optimizing a cold storage and heat storage load participating in a ramping market.

[0009] In one embodiment, the method for optimizing a cold storage and heat storage load participating in a ramping market comprises the following steps:

[0010] Based on the operating characteristics of the cold storage and heat storage load and the response mechanism of the cold storage and heat storage load to the ramping demand of the power system, a target function of economic benefits of the cold storage and heat storage load participating in the ramping market is established by dispatching the heat source unit and the water storage tank; and a constraint condition of energy optimization of the power system is established according to the target function of economic benefits of the cold storage and heat storage load participating in the ramping market.

[0011] According to the target function of economic benefits of the cold storage and heat storage load participating in the ramping market and the constraint condition of energy optimization of the power system, a solver is used to solve the load dispatching of the power system to obtain an optimal load dispatching scheme of the power system.

[0012] In one embodiment, the expression of the target function of economic benefits of the cold storage and heat storage load participating in the ramping market is as follows:

[0013]

[0014] In the formula, t represents a time; T represents a number of optimization periods; represents an up-ramping power of the i th heat source unit at the time t; represents a down-ramping power of the i th heat source unit at the time t; represents an up-ramping price at the time t; represents a down-ramping price at the time t; represents an electricity consumption power of the i th heat source unit at the time t; represents a real-time electricity price.

[0015] In one embodiment, the establishment of the constraint condition of energy optimization of the power system according to the target function of economic benefits of the cold storage and heat storage load participating in the ramping market comprises the following steps:

[0016] According to the target function of economic benefits of the cold storage and heat storage load participating in the ramping market, a power balance constraint of the ramping market is established by adjusting the power output of the heat source unit in each optimization period;

[0017] The power balance constraint of the climbing market is used to establish the energy balance constraint of the heat source unit and the water storage tank by the power and capacity limits of the heat source unit and the water storage tank.

[0018] Based on the topology of the pipeline, the mixed flow and temperature constraints of the pipeline in the power system are established, and the time delay and heat power constraints of the pipeline in the power system are established based on the heat loss caused by the time delay phenomenon in the pipeline.

[0019] According to the heat exchange between the room and the pipeline in the power system and the outside, a dynamic model of the room temperature is established, and a comfort constraint of indoor temperature is established according to the dynamic model of the room temperature.

[0020] In one embodiment, the power balance constraint of the climbing market includes an up-climbing power constraint and a down-climbing power constraint.

[0021] The expression of the up-climbing power constraint is:

[0022]

[0023] In the formula, represents the up-climbing power of the i-th heat source machine at time t; represents the power of the i-th heat source machine at time t; represents the upper limit of the power of the i-th heat source machine at time t;

[0024] The expression of the down-climbing power constraint is:

[0025]

[0026] In the formula, represents the down-climbing power of the i-th heat source machine at time t; represents the power of the i-th heat source machine at time t.

[0027] In one embodiment, the expression of the energy balance constraint of the heat source unit is:

[0028]

[0029] In the formula, represents the total power of the i-th heat source machine at time t; represents the heat storage power of the j-th water storage tank at time t; represents the heat release power of the j-th water storage tank at time t; P t pip represents the power provided by the heat source unit to the total pipeline at time t; represents the instantaneous mass flow rate of the total pipeline at time t; c w represents the specific heat capacity of water; T t ch,sdenotes the supply water temperature of the total pipe at time t; T t ch,r denotes the return water temperature of the total pipe at time t; COP denotes the performance coefficient of the heat source unit; denotes the upper limit of the power of the i-th heat source unit at time t;

[0030] The energy balance constraint expression of the water storage tank is:

[0031]

[0032]

[0033] In the formula, denotes the stored heat of the j-th water storage tank at time t+1; denotes the stored heat of the j-th water storage tank at time t; δ c denotes the heat loss rate of the water storage tank; η c.ch denotes the heat storage efficiency of the water storage tank; η c.dis denotes the heat release efficiency of the water storage tank; denotes the stored heat of the water storage tank at the beginning of the dispatching period; denotes the stored heat of the water storage tank at the end of the dispatching period; denotes the minimum stored heat of the j-th water storage tank; denotes the maximum stored heat of the j-th water storage tank; denotes the heat storage power of the j-th water storage tank at time t; denotes the upper limit of the heat storage power of the j-th water storage tank at time t; denotes the heat release power of the j-th water storage tank at time t; denotes the upper limit of the heat release power of the j-th water storage tank at time t, and Δt denotes an optimization period.

[0034] In one embodiment, the expression of the mixed flow and temperature constraints of the pipe in the power system is:

[0035]

[0036] In the formula, denotes the mass flow rate of the total pipe at time t; T t ch,r denotes the return water temperature of the total pipe at time t; m k,t denotes the mass flow rate of the k-th heating building at time t; denotes the return water temperature of the k-th heating building at time t; denotes the mass flow rate of the pressure balancer at time t; T t dec denotes the return water temperature of the pressure balancer at time t; cw cp represents the specific heat capacity of water; represents the arbitrary tth optimization period.

[0037] In one embodiment, the expression of the room temperature dynamic model is:

[0038]

[0039] wherein cp represents the specific heat capacity of water; and A cp represents the specific heat capacity of air; and p represents the air density; A V represents the volume of the room; k Vk represents the volume of the kth building; Tt+1 represents the indoor temperature at t+1 time; Tt represents the indoor temperature at t time; Gk represents the heat gain of the kth building at t time; Hk represents the heat loss of the kth building at t time; and k m represents the heat exchange efficiency of the pipe to the room; k,t mk represents the mass flow rate of water in the kth pipe at t time; w cp represents the specific heat capacity of water; Tk represents the supply water temperature of the kth pipe at t time; Tk represents the return water temperature of the kth pipe at t time; h represents the heat transfer coefficient; Ak represents the surface area of the kth building; Tt represents the indoor temperature at t time; and t out Tt represents the outdoor temperature at t time;

[0040] The comfort constraint expression of the indoor temperature is:

[0041]

[0042] wherein, Tmin represents the minimum temperature of the indoor comfort temperature at t time; Tmax represents the maximum temperature of the indoor comfort temperature at t time.

[0043] According to a second aspect of the embodiments of the present application, a cold and heat storage load participating in the climbing market optimization system is provided.

[0044] In one embodiment, the cold and heat storage load participating in the climbing market optimization system comprises:

[0045] The target function and constraint condition establishment module is configured to establish a target function of economic benefits of the cold storage load participating in the climbing market by scheduling the heat source unit and the water storage tank based on operation characteristics of the cold storage load and a response mechanism of the cold storage load to climbing demand of the power system, and establish a constraint condition of energy optimization of the power system according to the target function of economic benefits of the cold storage load participating in the climbing market.

[0046] The optimal load scheduling scheme solving module is configured to solve the load scheduling of the power system by using a solver according to the target function of economic benefits of the cold storage load participating in the climbing market and the constraint condition of energy optimization of the power system, and obtain an optimal load scheduling scheme of the power system.

[0047] In one embodiment, the target function of economic benefits of the cold storage load participating in the climbing market is expressed as:

[0048]

[0049] In the formula, t represents a time point, T represents a number of optimization periods, represents an up-climbing power of the i th heat source unit at the time t, represents a down-climbing power of the i th heat source unit at the time t, represents an up-climbing price at the time t, represents a down-climbing price at the time t, represents a power consumption of the i th heat source unit at the time t, and represents a real-time electricity price.

[0050] In one embodiment, the constraint condition of energy optimization of the power system established according to the target function of economic benefits of the cold storage load participating in the climbing market comprises:

[0051] The power balance constraint of the climbing market is established by adjusting power output of the heat source unit in each optimization period according to the target function of economic benefits of the cold storage load participating in the climbing market.

[0052] The energy balance constraint of the heat source unit and the water storage tank is established by using the power balance constraint of the climbing market and power and capacity limits of the heat source unit and the water storage tank.

[0053] The mixed flow and temperature constraint of the pipeline in the power system is established based on a topology structure of the pipeline, and the time delay and heat power constraint of the pipeline in the power system is established based on heat loss caused by time delay in the pipeline.

[0054] The comfort constraint of indoor temperature is established according to a room temperature dynamic model established based on heat exchange between a room and the pipeline in the power system and the outside world.

[0055] ​​​​​​In one embodiment, the power balance constraint of the climbing market comprises: an up-climbing power constraint and a down-climbing power constraint;

[0056] The expression of the up-climbing power constraint is:

[0057]

[0058] In the formula, represents the up-climbing power of the i-th heat source machine at time t; represents the power of the i-th heat source machine at time t; represents the upper limit of the power of the i-th heat source machine at time t;

[0059] The expression of the down-climbing power constraint is:

[0060]

[0061] In the formula, represents the down-climbing power of the i-th heat source machine at time t; represents the power of the i-th heat source machine at time t.

[0062] In one embodiment, the expression of the energy balance constraint of the heat source machine group is:

[0063]

[0064] In the formula, represents the total power of the i-th heat source machine at time t; represents the heat storage power of the j-th water storage tank at time t; represents the heat release power of the j-th water storage tank at time t; P t pip represents the power provided by the heat source machine group to the total pipeline at time t; represents the instantaneous mass flow rate of the total pipeline at time t; c w represents the specific heat capacity of water; T t ch,s represents the water supply temperature of the total pipeline at time t; T t ch,r represents the return water temperature of the total pipeline at time t; COP represents the performance coefficient of the heat source machine group; represents the upper limit of the power of the i-th heat source machine at time t;

[0065] The expression of the energy balance constraint of the water storage tank is:

[0066]

[0067] In the formula, represents the stored heat of the j-th water storage tank at time t+1; δ represents the heat stored in the j-th water tank at time t; c Indicates the heat loss rate of the water storage tank; η c.ch Indicates the heat storage efficiency of the water storage tank; η c.dis This indicates the heat release efficiency of the water storage tank; This indicates the amount of heat stored in the water storage tank at the beginning of the scheduling cycle. This indicates the amount of heat stored in the water storage tank at the end of the scheduling cycle. This represents the minimum heat storage capacity of the j-th water tank; This represents the maximum heat storage capacity of the j-th water storage tank; This represents the heat storage power of the j-th water tank at time t; This represents the upper limit of the heat storage capacity of the j-th water storage tank at time t; Let represent the heat release power of the j-th water storage tank at time t; Δt represents the upper limit of the heat release power of the j-th water tank at time t, and Δt represents an optimization period.

[0068] In one embodiment, the expression for the mixed flow rate and temperature constraints of the pipeline in the power system is:

[0069]

[0070] In the formula, T represents the mass flow rate of the main pipeline at time t; t ch,r This represents the return water temperature in the main pipeline at time t; m k,t This represents the mass flow rate of the k-th heated building at time t; This represents the return water temperature of the k-th heated building at time t; T represents the mass flow rate of the pressure balancer at time t; t dec c represents the return water temperature of the pressure balancer at time t; w This indicates the specific heat capacity of water; Let t represent any t-th optimization time period.

[0071] In one embodiment, the expression for the room temperature dynamic model is:

[0072]

[0073] In the formula, c A ρ represents the specific heat capacity of air. A V represents air density. k This represents the spatial volume of the k-th building; This represents the indoor temperature at time t+1; This represents the indoor temperature at time t; represents the heat gain obtained by the kth building at time t; represents the heat loss of the kth building at time t; η k represents the heat exchange efficiency of the pipeline to the room; m k,t represents the mass flow of water in the kth pipeline at time t; c w represents the specific heat capacity of water; represents the water supply temperature of the kth pipeline at time t; represents the return water temperature of the kth pipeline at time t; represents the heat transfer coefficient; represents the surface area of the kth building; represents the indoor temperature at time t; T t out represents the outdoor environment temperature at time t;

[0074] The comfort constraint expression of the indoor temperature is:

[0075]

[0076] In the formula, represents the minimum temperature of the indoor comfort temperature at time t; represents the maximum temperature of the indoor comfort temperature at time t.

[0077] According to a third aspect of the embodiments of the present application, a computer device is provided.

[0078] In one embodiment, the computer device comprises a memory and a processor, the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0079] According to a fourth aspect of the embodiments of the present application, a computer readable storage medium is provided.

[0080] In one embodiment, the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the steps of the above method.

[0081] The technical solutions provided by the embodiments of the present application can include the following beneficial effects:

[0082] The present application realizes the reasonable scheduling of the heat source unit, the water storage tank and the pipeline through the optimization model with the target of maximizing economic benefits, so that the load side can flexibly participate in the electricity market, obtain higher economic benefits while meeting the demand of power grid regulation, promote the low-carbon development of the power system, and provide a practical reference scheme for energy system planning and construction.

[0083] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0084] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0085] Figure 1 This is a flowchart illustrating a method for optimizing the participation of cold and heat storage loads in a ramp-up market, according to an exemplary embodiment.

[0086] Figure 2 This is a block diagram illustrating the principle of a market optimization system for participating in cold and heat storage loads according to an exemplary embodiment;

[0087] Figure 3 This is a schematic diagram of the structure of a computer device according to an exemplary embodiment;

[0088] Figure 4 This is a schematic diagram of the topology of a cold and heat storage load system in a market optimization method for participating in cold and heat storage loads according to an exemplary embodiment. Detailed Implementation

[0089] The following description and accompanying drawings fully illustrate specific embodiments described herein to enable those skilled in the art to practice them. Some embodiments may include or substitute parts and features of other embodiments. The scope of the embodiments herein encompasses the entire scope of the claims and all available equivalents thereof. Throughout this document, the terms “first,” “second,” etc., are used only to distinguish one element from another without requiring or implying any actual relationship or order between the elements. Indeed, a first element can also be referred to as a second element, and vice versa. Furthermore, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a structure, apparatus, or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a structure, apparatus, or device. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the structure, apparatus, or device that includes said element. The various embodiments described herein are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments; similar or identical parts between embodiments can be referred to interchangeably.

[0090] The terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like as used herein to indicate orientation or positional relationships based on the orientations or positional relationships shown in the drawings, are for purposes of this description only, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application. In the description of the description, unless otherwise specified and limited, the terms "mount", "connect", "connection" should be interpreted broadly, for example, can be mechanical connection or electrical connection, can be internal communication of two elements, can be direct connection, or indirect connection through intermediate medium, and the specific meaning of the above terms can be understood by the person skilled in the art according to the specific circumstances.

[0091] In this paper, unless otherwise specified, the term "a plurality of" means two or more.

[0092] In this paper, the character " / " represents the relationship between the front and rear objects. For example, A / B represents: A or B.

[0093] In this paper, the term "and / or" is a description of the relationship between the objects, which means that there can be three relationships. For example, A and / or B, which means: A or B, or, A and B, three relationships.

[0094] It should be understood that although each step in the flowchart is displayed in sequence according to the direction of the arrow, these steps are not necessarily executed in sequence according to the direction of the arrow. Unless otherwise specified in this paper, the execution of these steps has no strict order limitation, and these steps can be executed in other order. Moreover, at least part of the steps in the figure can include multiple sub-steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least part of other steps or other steps or stages.

[0095] The various modules in the device or system of the present application can be realized by software, hardware and their combination in whole or in part. The above modules can be embedded in or independent of the processor in the computer device in hardware form, or stored in the memory in the computer device in software form, so as to call and execute the operations corresponding to the above modules by the processor.

[0096] In the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0097] Figure 1An embodiment of the method for optimizing the cold storage load participating in the climbing market is shown.

[0098] In this alternative embodiment, the method for optimizing the cold storage load participating in the climbing market comprises the following steps:

[0099] In step S101, based on the operating characteristics of the cold storage load and the response mechanism of the cold storage load to the climbing demand of the power system, the target function of the economic benefit of the cold storage load participating in the climbing market is established by scheduling the heat source unit and the water storage tank, with the optimization target of maximizing the economic benefit of the climbing market; and the constraint condition of the energy optimization of the power system is established according to the target function of the economic benefit of the cold storage load participating in the climbing market.

[0100] In step S103, the load scheduling of the power system is solved by using the solver according to the target function of the economic benefit of the cold storage load participating in the climbing market and the constraint condition of the energy optimization of the power system, to obtain the optimal load scheduling scheme of the power system.

[0101] It should be noted that the optimal scheduling scheme of the heat source unit, the water storage tank and the pipeline in each period is determined according to the established target function of the economic benefit of the cold storage load participating in the climbing market and various constraint conditions, so as to maximize the economic benefit of the cold storage load participating in the climbing market and ensure the stable operation of the system and the comfort of the users.

[0102] Specifically, the above steps can be summarized as two stages. The first stage is to establish the target function, that is, to establish the target function of the economic benefit of the cold storage load participating in the climbing market by scheduling the heat source unit and the water storage tank, with the optimization target of maximizing the economic benefit of the climbing market. The second stage is to establish various constraint conditions according to the target function established in the first stage. First, the power balance constraint of the system is established by adjusting the power output of the heat source unit. Second, the energy balance constraint of the heat source unit and the water storage tank is considered to ensure that various devices can maintain the stability of energy during the scheduling process. Third, the flow and temperature constraint of the pipeline is established to consider the heat loss caused by the time delay phenomenon in the pipeline, so as to ensure the efficient transmission of heat energy in the system. Finally, the room temperature dynamic model and the temperature control demand constraint are established to ensure the comfort of the users. The entire system is optimized and solved by using the GUROBI solver to obtain the optimal load scheduling scheme, so as to maximize the economic benefit of the system and ensure the safety, stability and efficiency of the system operation.

[0103] In this alternative embodiment, the expression of the target function of the economic benefit of the cold storage load participating in the climbing market is as follows:

[0104]

[0105] In the formula, t represents time; T represents the number of optimization periods, T = 96, that is, 15 minutes as an optimization period in a day; represents the up-climbing power of the i th heat source machine at t time; represents the down-climbing power of the i th heat source machine at t time; represents the up-climbing price at t time; represents the down-climbing price at t time; represents the power consumption of the i th heat source machine at t time; represents the real-time electricity price.

[0106] It should be explained that the first and second terms in the objective function represent the up-climbing and down-climbing benefits of the heat source unit respectively, and the third term is the power consumption cost of the heat source unit. By maximizing the up-climbing and down-climbing power benefits and minimizing the power consumption cost, the maximum economic benefit is achieved.

[0107] In this optional embodiment, when establishing the constraint conditions of the energy optimization of the power system according to the target function of the economic benefit of the cold storage and heat storage load participating in the climbing market, the power balance constraint of the climbing market can be established by adjusting the power output of the heat source unit at each optimization period according to the target function of the economic benefit of the cold storage and heat storage load participating in the climbing market; the energy balance constraint of the heat source unit and the storage tank can be established by using the power balance constraint of the climbing market and by the power and capacity limitations of the heat source unit and the storage tank; the mixed flow and temperature constraint of the pipeline in the power system can be established based on the topological structure of the pipeline, and the time delay and heat power constraint of the pipeline in the power system can be established based on the heat loss caused by the time delay phenomenon in the pipeline; the comfort constraint of the indoor temperature can be established according to the room temperature dynamic model established according to the heat exchange between the room and the pipeline in the power system and the outside world.

[0108] As shown in Figure 4 , it is a schematic diagram of the topological structure of the cold storage and heat storage load system. According to the connection mode of each component in the figure and the energy transmission and flow process in the system, various constraint conditions and solving processes are established.

[0109] In this optional embodiment, the power balance constraint of the climbing market includes an up-climbing power constraint and a down-climbing power constraint. The up-climbing power is the difference between the power upper limit of the heat source and the current power consumption. When up-climbing, the heat source unit responds to the demand by reducing the output power. The current power consumption of the heat source is taken as the down-climbing power. When down-climbing, the heat source unit responds to the demand by increasing the output power.

[0110] The expression of the up-climbing power constraint is:

[0111]

[0112] wherein, represents the up-ramp power of the ith heat source machine at time t; represents the power of the ith heat source machine at time t; represents the upper limit of the power of the ith heat source machine at time t;

[0113] The expression of the down-ramp power constraint is:

[0114]

[0115] wherein, represents the down-ramp power of the ith heat source machine at time t; represents the power of the ith heat source machine at time t.

[0116] In this alternative embodiment, the expression of the energy balance constraint of the heat source machine group is:

[0117]

[0118] wherein, represents the total power of the ith heat source machine at time t; represents the heat storage power of the jth water storage tank at time t; represents the heat release power of the jth water storage tank at time t; t pip represents the power provided by the heat source machine group to the total pipeline at time t; represents the instantaneous mass flow rate of the total pipeline at time t; c w represents the specific heat capacity of water; T t ch,s represents the water supply temperature of the total pipeline at time t; T t ch,r represents the return water temperature of the total pipeline at time t; COP represents the performance coefficient of the heat source machine group; represents the upper limit of the power of the ith heat source machine at time t;

[0119] wherein, for the first expression in the energy balance constraint expression of the heat source machine group: the total power of the heat source machine group needs to meet the heat storage power of the water storage tank and the demand power for supplying heat to the total pipeline;

[0120] for the second expression in the energy balance constraint expression of the heat source machine group: the performance of the heat source machine group is considered by COP to calculate the transmission of the heat supply power of the heat source machine group;

[0121] for the third expression in the energy balance constraint expression of the heat source machine group: the power of the heat source machine group is limited to ensure that its power is within a reasonable range.

[0122] ​The energy balance constraint expression of the water storage tank is:

[0123]

[0124] In the formula, Qj(t+1) represents the stored heat of the jth water storage tank at t+1 time; Qj(t) represents the stored heat of the jth water storage tank at t time; δ c η represents the heat loss rate of the water storage tank; c.ch η represents the heat storage efficiency of the water storage tank; c.dis η represents the heat release efficiency of the water storage tank; Qj(t0) represents the heat storage amount of the water storage tank at the beginning of the scheduling period; Qj(t1) represents the heat storage amount of the water storage tank at the end of the scheduling period; Qj,min represents the minimum heat storage amount of the jth water storage tank; Qj,max represents the maximum heat storage amount of the jth water storage tank; Pj(t) represents the heat storage power of the jth water storage tank at t time; Pj,max(t) represents the upper limit of the heat storage power of the jth water storage tank at t time; Qj(t) represents the heat release power of the jth water storage tank at t time; Qj,max(t) represents the upper limit of the heat release power of the jth water storage tank at t time, and Δt represents an optimization period.

[0125] Among the first and second expressions in the energy balance constraint expression of the water storage tank: the heat loss and the heat storage and release power of the water storage tank are considered, the balance relationship of the energy of the water storage tank with time is established, and the energy of the water storage tank remains constant at the beginning and combination of the optimization period, that is, the system remains stable and continuous in the entire period;

[0126] Among the third expression in the energy balance constraint expression of the water storage tank: the energy storage amount of the water storage tank is limited within its capacity range;

[0127] Among the fourth and fifth expressions in the energy balance constraint expression of the water storage tank: it is ensured that the power of the water storage tank during heat storage and release does not exceed the maximum power designed by the equipment.

[0128] In this optional embodiment, the expression of the mixed flow and temperature constraint of the pipeline in the power system is:

[0129]

[0130] In the formula, T represents the mass flow rate of the total pipeline at t time; T t ch,r T represents the return water temperature of the total pipeline at t time; m k,trepresents the mass flow rate of the kth heating building at time t; represents the return water temperature of the kth heating building at time t; represents the mass flow rate of the pressure balancer at time t; t dec represents the return water temperature of the pressure balancer at time t; w represents the specific heat capacity of water, in kJ / (kg·℃); represents the tth optimization period.

[0131] wherein, for the first of the above expressions of the mixed flow and temperature constraints of the pipes in the power system: represents the mass flow of the total pipe being equal to the sum of the mass flow of the return water of the buildings and the mass flow of the pressure balancer;

[0132] for the second of the above expressions of the mixed flow and temperature constraints of the pipes in the power system: represents the heat in the return water in the total pipe being equal to the sum of the heat of the return water path and the heat of the pressure balancer, through the mixed flow and temperature constraints of the pipes, the balance between each branch and pipe in the heating system is ensured.

[0133] Specifically, when establishing the time lag and heat power constraints of the pipes in the entire system, the heat loss caused by the time lag phenomenon in the pipes needs to be considered, and the heat loss caused by the time lag phenomenon in the pipes is represented as follows:

[0134]

[0135] wherein, T t ch,s represents the supply water temperature of the total pipe at time t; represents the intermediate variable of the supply water temperature of the kth pipe at time t+1; represents the intermediate variable of the supply water temperature of the kth pipe at time t; η pipe represents the heat transfer coefficient of the supply pipe; T t out represents the ambient temperature; represents the supply water temperature of the kth pipe at time t; represents the tth optimization period.

[0136] In this optional embodiment, the expression of the room temperature dynamic model is:

[0137]

[0138] wherein, c A represents the specific heat capacity of air; ρ A represents the air density; V k represents the space volume of the kth building; represents the indoor temperature at time t+1; represents the indoor temperature at time t; represents the heat gain of the kth building at time t; represents the heat loss of the kth building at time t; η k represents the heat exchange efficiency of the pipeline to the room; m k,t represents the mass flow of water in the kth pipeline at time t; c w represents the specific heat capacity of water; represents the water supply temperature of the kth pipeline at time t; represents the return water temperature of the kth pipeline at time t; represents the heat transfer coefficient, with the unit of kW / (m 2 ·℃); represents the surface area of the kth building, with the unit of m 2 ; represents the indoor temperature at time t; T t out represents the outdoor environment temperature at time t;

[0139] Specifically, based on the above-mentioned room temperature dynamic model, the change of the room temperature in the next time period is calculated by considering the heat gain and heat loss of the room, so that the room temperature can be adjusted according to the actual heating condition.

[0140] The comfort constraint expression of the indoor temperature is:

[0141]

[0142] In the formula, represents the minimum temperature of the indoor comfort temperature at time t; represents the maximum temperature of the indoor comfort temperature at time t.

[0143] Figure 2 An embodiment of the cold storage and heat storage load participating in the climbing market optimization system is shown.

[0144] In this optional embodiment, the cold storage and heat storage load participating in the climbing market optimization system comprises:

[0145] The objective function and constraint condition establishment module 201 is configured to, based on the operating characteristics of the cold storage and heat storage load and the response mechanism of the cold storage and heat storage load to the climbing demand of the power system, establish an objective function of the economic benefits of the cold storage and heat storage load participating in the climbing market by scheduling the heat source unit and the water storage tank, and establish a constraint condition of the energy optimization of the power system according to the objective function of the economic benefits of the cold storage and heat storage load participating in the climbing market;

[0146] The optimal load scheduling scheme solving module 203 is configured to solve the load scheduling of the power system by using a solver according to the target function of the economic benefit of the cold storage load participating in the ramping market and the constraint condition of the energy optimization of the power system, to obtain an optimal load scheduling scheme of the power system.

[0147] In the optional embodiment, the expression of the target function of the economic benefit of the cold storage load participating in the ramping market is as follows:

[0148]

[0149] In the formula, t represents a time point; T represents a number of optimization periods; represents the up-ramping power of the i th heat source machine at the time t; represents the down-ramping power of the i th heat source machine at the time t; represents the up-ramping price at the time t; represents the down-ramping price at the time t; represents the power consumption of the i th heat source machine at the time t; represents the real-time electricity price.

[0150] In the optional embodiment, the constraint condition of the energy optimization of the power system according to the target function of the economic benefit of the cold storage load participating in the ramping market comprises: establishing a power balance constraint of the ramping market by adjusting the power output of the heat source unit at each optimization period according to the target function of the economic benefit of the cold storage load participating in the ramping market; establishing an energy balance constraint of the heat source unit and the water storage tank by using the power balance constraint of the ramping market and the power and capacity limits of the heat source unit and the water storage tank; establishing a mixed flow and temperature constraint of the pipeline in the power system based on the topological structure of the pipeline, and establishing a time delay and heat power constraint of the pipeline in the power system based on the heat loss caused by the time delay phenomenon in the pipeline; establishing a room temperature dynamic model according to the heat exchange between the room and the pipeline in the power system and the outside world, and establishing a comfort constraint of the indoor temperature according to the room temperature dynamic model.

[0151] In the optional embodiment, the power balance constraint of the ramping market comprises: an up-ramping power constraint and a down-ramping power constraint.

[0152] The expression of the up-ramping power constraint is as follows:

[0153]

[0154] In the formula, represents the up-ramping power of the i th heat source machine at the time t; represents the power of the i th heat source machine at the time t; represents the upper limit of the power of the i th heat source machine at the time t;

[0155] The expression of the lower ramping power constraint is:

[0156]

[0157] wherein, Pil(t) represents the lower ramping power of the ith heat source machine at time t; Pil(t) represents the power of the ith heat source machine at time t.

[0158] In this alternative embodiment, the expression of the energy balance constraint of the heat source set is:

[0159]

[0160] wherein, Pil(t) represents the total power of the ith heat source machine at time t; Qj(t) represents the heat storage power of the jth water storage tank at time t; Qj(t) represents the heat release power of the jth water storage tank at time t; P t pip P(t) represents the power provided by the heat source set to the main pipeline at time t; m(t) represents the instantaneous mass flow rate of the main pipeline at time t; c w Cp represents the specific heat capacity of water; T t ch,s Tin(t) represents the water supply temperature of the main pipeline at time t; T t ch,r Tout(t) represents the return water temperature of the main pipeline at time t; COP represents the performance coefficient of the heat source set; Pil(t) represents the upper limit of the power of the ith heat source machine at time t;

[0161] The expression of the energy balance constraint of the water storage tank is:

[0162]

[0163] wherein, Qj(t+1) represents the stored heat of the jth water storage tank at time t+1; Qj(t) represents the stored heat of the jth water storage tank at time t; δ c η represents the heat loss rate of the water storage tank; η c.ch η represents the heat storage efficiency of the water storage tank; η c.dis η represents the heat release efficiency of the water storage tank; Qj(0) represents the stored heat of the water storage tank at the beginning of the dispatching period; Qj(T) represents the stored heat of the water storage tank at the end of the dispatching period; Qj,min represents the minimum stored heat of the jth water storage tank; Qj,max represents the maximum stored heat of the jth water storage tank; Qj(t) represents the heat storage power of the jth water storage tank at time t; represents the upper limit of the heat storage power of the jth water storage tank at time t; represents the heat release power of the jth water storage tank at time t; represents the upper limit of the heat release power of the jth water storage tank at time t, and Δt represents an optimization period, which is 15 minutes, and one day is divided into 96 periods.

[0164] In this alternative embodiment, the expression of the mixed flow and temperature constraints of the pipes in the power system is:

[0165]

[0166] wherein, represents the mass flow rate of the total pipe at time t; T t ch,r represents the return water temperature of the total pipe at time t; m k,t represents the mass flow rate of the kth heating building at time t; represents the return water temperature of the kth heating building at time t; represents the mass flow rate of the pressure balancer at time t; T t dec represents the return water temperature of the pressure balancer at time t; c w represents the specific heat capacity of water; represents any tth optimization period.

[0167] In this alternative embodiment, the expression of the room temperature dynamic model is:

[0168]

[0169] wherein, c A represents the specific heat capacity of air; p A represents the air density; V k represents the space volume of the kth building; represents the indoor temperature at time t+1; represents the indoor temperature at time t; represents the heat gain obtained by the kth building at time t; represents the heat loss of the kth building at time t; η k represents the heat exchange efficiency of the pipe to the room; m k,t represents the mass flow rate of water in the kth pipe at time t; c w represents the specific heat capacity of water; represents the supply water temperature of the kth pipe at time t; represents the return water temperature of the kth pipe at time t; represents the heat transfer coefficient; denotes the surface area of the kth building; denotes the indoor temperature at time t; t out denotes the outdoor environment temperature at time t;

[0170] The comfort constraint expression of the indoor temperature is:

[0171]

[0172] In the formula, denotes the minimum temperature of the indoor comfort temperature at time t; denotes the maximum temperature of the indoor comfort temperature at time t.

[0173] In an embodiment, a computer device is provided, which can be a server, and an internal structure diagram thereof can be as shown in Figure 3 The computer device includes a processor, a memory and a network interface connected through a system bus. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for running the operating system and the computer program in the non-volatile storage medium. The database of the computer device is configured to store static information and dynamic information data. The network interface of the computer device is configured to communicate with an external terminal through a network connection. The computer program is executed by the processor to implement the steps in the above method embodiments.

[0174] Those skilled in the art can understand that Figure 3 The structure shown in the above embodiment is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. Specifically, the computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0175] In addition, the present application also provides a computer device including a memory and a processor, and the memory stores a computer program. The processor executes the computer program to implement the steps in the above method embodiments.

[0176] In addition, the present application also provides a computer readable storage medium, which stores a computer program. The computer program is executed by the processor to implement the steps in the above method embodiments.

[0177] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiments. Any reference to memory, storage, database or other medium used in each embodiment of the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0178] The present application is not limited to the structures described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present application is only limited by the appended claims.

Claims

1. A method for optimizing the cold storage load participating in the climbing market, characterized in that, The method comprises the following steps: Based on the operating characteristics of the cold storage load and the response mechanism of the cold storage load to the climbing demand of the power system, a target function of economic benefits of the cold storage load participating in the climbing market is established by scheduling the heat source unit and the water storage tank; and constraint conditions of energy optimization of the power system are established according to the target function of economic benefits of the cold storage load participating in the climbing market; The expression of the target function of economic benefits of the cold storage load participating in the climbing market is: In the formula, t represents time; T represents the number of optimization periods; represents the up ramping power of the i-th heat source machine at time t; represents the down ramping power of the i-th heat source machine at time t; represents the up ramping price at time t; represents the down ramping price at time t; represents the power consumption of the i-th heat source machine at time t; represents the real-time electricity price; The constraint conditions of energy optimization of the power system established according to the target function of economic benefits of the cold storage load participating in the climbing market comprise the following steps: According to the target function of economic benefits of the cold storage load participating in the climbing market, power balance constraints of the climbing market are established by adjusting the power output of the heat source unit in each optimization period; By using the power balance constraints of the climbing market, energy balance constraints of the heat source unit and the water storage tank are established by the power and capacity limits of the heat source unit and the water storage tank themselves; Based on the topological structure of the pipeline, mixed flow and temperature constraints of the pipeline in the power system are established, and time delay and heat power constraints of the pipeline in the power system are established based on heat loss caused by time delay in the pipeline; According to heat exchange between the room and the pipeline in the power system and the outside, a room temperature dynamic model is established, and comfort constraints of indoor temperature are established according to the room temperature dynamic model; According to the target function of economic benefits of the cold storage load participating in the climbing market and the constraint conditions of energy optimization of the power system, the load scheduling of the power system is solved by using a solver, and an optimal load scheduling scheme of the power system is obtained.

2. The method according to claim 1, wherein, The power balance constraints of the climbing market comprise upper climbing power constraints and lower climbing power constraints; The expression of the upper climbing power constraints is: In the formula, represents the upper ramping power of the i-th heat source machine at time t; represents the power of the i-th heat source machine at time t; represents the upper limit of the power of the i-th heat source machine at time t; The expression of the lower climbing power constraints is: In the formula, represents the down ramp power of the i-th heat source machine at time t; represents the power of the i-th heat source machine at time t.

3. The method according to claim 1, wherein, The expression of the energy balance constraints of the heat source unit is: wherein, Pti(t) represents the total power of the i-th heat source machine at time t; Pj(t) represents the heat storage power of the j-th water storage tank at time t; Pj(t) represents the heat storage power of the j-th water storage tank at time t; t pip P(t) represents the power provided by the heat source set to the main pipeline at time t; m(t) represents the instantaneous mass flow rate of the main pipeline at time t; w Cp represents the specific heat capacity of water; t ch,s T(t) represents the water supply temperature of the main pipeline at time t; t ch,r T(t) represents the water return temperature of the main pipeline at time t; COP represents the performance coefficient of the heat source set; Pti(t) represents the upper limit of the power of the i-th heat source machine at time t.

4. The method of claim 1, wherein, The expression of the energy balance constraints of the water storage tank is: wherein, represents the stored heat of the jth water storage tank at t+1 time; represents the stored heat of the jth water storage tank at t time; δ c represents the heat loss rate of the water storage tank; η c.ch represents the heat storage efficiency of the water storage tank; η c.dis represents the heat release efficiency of the water storage tank; represents the heat storage amount of the water storage tank at the beginning of the dispatching period; represents the heat storage amount of the water storage tank at the end of the dispatching period; represents the minimum heat storage amount of the jth water storage tank; represents the maximum heat storage amount of the jth water storage tank; represents the heat storage power of the jth water storage tank at t time; represents the upper limit of the heat storage power of the jth water storage tank at t time; represents the heat release power of the jth water storage tank at t time; represents the upper limit of the heat release power of the jth water storage tank at t time, and Δt represents an optimization period.

5. The method of claim 1, wherein, The expression of the mixed flow and temperature constraints of the pipeline in the power system is: wherein mT represents the mass flow rate of the total pipe at time t; T t ch,r mT represents the return water temperature of the total pipe at time t; m k,t mTk represents the mass flow rate of the kth heated building at time t; mTk represents the return water temperature of the kth heated building at time t; mT represents the mass flow rate of the pressure balancer at time t; T t dec mT represents the return water temperature of the pressure balancer at time t; c w c represents the specific heat capacity of water; t represents any tth optimization period.

6. The method of claim 1, wherein, The expression of the room temperature dynamic model is: where c A represents the specific heat capacity of air; p A represents the air density; V k represents the space volume of the kth building; represents the indoor temperature at t+1; represents the indoor temperature at t; represents the heat gain of the kth building at t; represents the heat loss of the kth building at t; η k represents the heat exchange efficiency of the pipe to the room; m k,t represents the mass flow rate of water in the kth pipe at t; c w represents the specific heat capacity of water; represents the water supply temperature of the kth pipe at t; represents the return water temperature of the kth pipe at t; represents the heat transfer coefficient; represents the surface area of the kth building; represents the indoor temperature at t; T t out represents the ambient temperature at t.

7. The method of claim 1, wherein, The expression of the comfort constraints of indoor temperature is: In the formula, represents the minimum temperature of the indoor comfort temperature at time t; represents the maximum temperature of the indoor comfort temperature at time t.

8. A cold and heat storage load participating in the ramp market optimization system, characterized in that, The method comprises the following steps: Based on the operating characteristics of the cold storage load and the response mechanism of the cold storage load to the climbing demand of the power system, a target function of economic benefits of the cold storage load participating in the climbing market is established by scheduling the heat source unit and the water storage tank; and constraint conditions of energy optimization of the power system are established according to the target function of economic benefits of the cold storage load participating in the climbing market; The expression of the target function of economic benefits of the cold storage load participating in the climbing market is: In the formula, t represents time; T represents the number of optimization periods; represents the up ramping power of the i-th heat source machine at time t; represents the down ramping power of the i-th heat source machine at time t; represents the up ramping price at time t; represents the down ramping price at time t; represents the power consumption of the i-th heat source machine at time t; represents the real-time electricity price; The constraint conditions of energy optimization of the power system established according to the target function of economic benefits of the cold storage load participating in the climbing market comprise the following steps: According to the target function of economic benefits of the cold storage load participating in the climbing market, power balance constraints of the climbing market are established by adjusting the power output of the heat source unit in each optimization period; By using the power balance constraints of the climbing market, energy balance constraints of the heat source unit and the water storage tank are established by the power and capacity limits of the heat source unit and the water storage tank themselves; Based on the pipeline-based topology, mixed flow and temperature constraints of the pipeline in the power system are established, and time delay and heat power constraints of the pipeline in the power system are established based on heat loss caused by time delay phenomenon in the pipeline; According to heat exchange of the room with the pipeline in the power system and the outside world, a room temperature dynamic model is established, and comfort constraints of indoor temperature are established according to the room temperature dynamic model; According to an objective function of economic benefits of the climbing market participated by cold and heat storage loads and constraint conditions of energy optimization of the power system, a solver is used to solve load scheduling of the power system, so as to obtain an optimal load scheduling scheme of the power system.

9. The cold and heat storage load participation ramp market optimization system according to claim 8, characterized in that, The power balance constraint of the climbing market comprises an up-climbing power constraint and a down-climbing power constraint. An expression of the up-climbing power constraint is: In the formula, represents the upper ramping power of the i-th heat source machine at time t; represents the power of the i-th heat source machine at time t; represents the upper limit of the power of the i-th heat source machine at time t; An expression of the down-climbing power constraint is: In the formula, represents the down ramp power of the i-th heat source machine at time t; represents the power of the i-th heat source machine at time t.

10. The cold and heat storage load participation ramp market optimization system according to claim 8, characterized in that, An expression of the energy balance constraint of the heat source unit is: wherein, Pti(t) represents the total power of the i-th heat source machine at time t; Pj(t) represents the power of the j-th water storage tank at time t; Pj(t) represents the power of the j-th water storage tank at time t; t pip P(t) represents the power provided by the heat source set to the main pipe at time t; m(t) represents the instantaneous mass flow rate of the main pipe at time t; w Cp represents the specific heat capacity of water; t ch,s T(t) represents the water supply temperature of the main pipe at time t; t ch,r T(t) represents the water return temperature of the main pipe at time t; COP represents the performance coefficient of the heat source set; Pti(t) represents the upper limit of the power of the i-th heat source machine at time t.

11. The cold and heat storage load participation ramp market optimization system according to claim 8, characterized in that, An expression of the energy balance constraint of the water storage tank is: wherein, represents the stored heat of the jth water storage tank at t + 1 time; represents the stored heat of the jth water storage tank at t time; δ c represents the heat loss rate of the water storage tank; η c.ch represents the heat storage efficiency of the water storage tank; η c.dis represents the heat release efficiency of the water storage tank; represents the heat storage amount of the water storage tank at the beginning of the dispatching period; represents the heat storage amount of the water storage tank at the end of the dispatching period; represents the minimum heat storage amount of the jth water storage tank; represents the maximum heat storage amount of the jth water storage tank; represents the heat storage power of the jth water storage tank at t time; represents the upper limit of the heat storage power of the jth water storage tank at t time; represents the heat release power of the jth water storage tank at t time; represents the upper limit of the heat release power of the jth water storage tank at t time, and Δt represents an optimization period.

12. The cold and heat storage load participation ramp market optimization system according to claim 8, wherein, An expression of the mixed flow and temperature constraint of the pipeline in the power system is: wherein Qtotal(t) represents the mass flow rate of the total pipe at time t; T t ch,r Treturn(t) represents the return water temperature of the total pipe at time t; m k,t Qk(t) represents the mass flow rate of the kth heated building at time t; Treturn k(t) represents the return water temperature of the kth heated building at time t; Qpb(t) represents the mass flow rate of the pressure balancer at time t; T t dec Treturn pb(t) represents the return water temperature of the pressure balancer at time t; c w Cp represents the specific heat capacity of water; t represents any tth optimization period.

13. The cold and heat storage load participation ramp market optimization system according to claim 12, characterized in that, An expression of the room temperature dynamic model is: where c A represents the specific heat capacity of air; p A represents the air density; V k represents the space volume of the kth building; represents the indoor temperature at t+1; T represents the indoor temperature at t; T represents the heat gain obtained by the kth building at t; Q represents the heat loss of the kth building at t; η k represents the heat exchange efficiency of the pipe to the room; m k,t represents the mass flow rate of water in the kth pipe at t; c w represents the specific heat capacity of water; represents the water supply temperature of the kth pipe at t; T represents the return water temperature of the kth pipe at t; T represents the heat transfer coefficient; represents the surface area of the kth building; represents the indoor temperature at t; T t out represents the ambient temperature at t.

14. The cold and heat storage load participation ramp market optimization system according to claim 10, wherein, An expression of the comfort constraint of the indoor temperature is: In the formula, represents the minimum temperature of the indoor comfort temperature at the time t; represents the maximum temperature of the indoor comfort temperature at the time t.

15. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that, The processor implements the steps of the method of any one of claims 1 to 7 when executing the computer program.

16. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program implements the steps of the method of any one of claims 1 to 7 when executed by the processor.

Images