A comprehensive energy inertia support method considering reasonable simplification of gas network constraints

Abstract

The application discloses a kind of comprehensive energy inertia support method considering gas network constraint reasonable simplification, belong to comprehensive energy technical field;Including considering the similarity of comprehensive energy system thermal inertia and gas inertia output form, the comprehensive energy inertia support model considering gas thermal inertia joint output is established;Considering natural gas network constraint, and based on the comprehensive energy inertia support model of gas thermal inertia joint output, the comprehensive energy gas thermal inertia support optimization model considering natural gas network constraint is established;Based on the comprehensive energy gas thermal inertia support optimization model considering natural gas network constraint, simplify natural gas network constraint, establish the comprehensive energy gas thermal inertia support optimization model considering natural gas network complex constraint simplification condition;Considering the relationship between the upper limit of thermal inertia output and power turning point, based on the comprehensive energy gas thermal inertia support model considering natural gas network complex constraint simplification condition, establish the inertia support model of gas network constraint reasonable simplification applicable to engineering practice.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of comprehensive energy, and particularly relates to a comprehensive energy inertia support method considering reasonable simplification of gas network constraints. BACKGROUND

[0002] Increasing new energy penetration rate increases the uncertainty of power grid output power, thereby reducing the reliability of power grid operation. In order to guarantee continuous and reliable power supply, it has become a current development trend to use the gas-heat inertia resources of the comprehensive energy system coupling electricity, gas and heat to guarantee reliable power supply. However, the existing research on the inertia resources of the natural gas system tends to develop towards fine modeling of the internal natural gas network. At the same time, considering comprehensive natural gas network constraints will inevitably increase the complexity of system modeling and reduce the calculation speed of the optimization model, which has a particularly great influence on the response speed of the inertia support method in the emergency power shortage scenario. SUMMARY

[0003] In view of the deficiencies of the prior art, the purpose of the present application is to provide a comprehensive energy inertia support method considering reasonable simplification of gas network constraints.

[0004] The purpose of the present application can be achieved by the following technical solutions:

[0005] A comprehensive energy inertia support method considering reasonable simplification of gas network constraints comprises the following steps:

[0006] S1, considering the similarity of the heat inertia and gas inertia output forms of the comprehensive energy system, a comprehensive energy inertia support model considering gas-heat inertia joint output is established;

[0007] S2, considering the natural gas network constraints, and based on the comprehensive energy inertia support model considering gas-heat inertia joint output, a comprehensive energy gas-heat inertia support optimization model considering the natural gas network constraints is established;

[0008] S3, based on the comprehensive energy gas-heat inertia support optimization model considering the natural gas network constraints, the natural gas network constraints are simplified, and a comprehensive energy gas-heat inertia support optimization model considering the simplified conditions of the complex constraints of the natural gas network is established;

[0009] S4, considering the relationship between the upper limit of the heat inertia output and the power turning point, based on the comprehensive energy gas-heat inertia support model considering the simplified conditions of the complex constraints of the natural gas network, a gas network constraint reasonable simplification inertia support model suitable for engineering practice is established:

[0010] P shortage =σ1P turning +σ2

[0011] In the formula, P turning is the power turning point corresponding to the upper limit of the heat inertia output, Pshortage σ1 and σ2 are coefficient constants for initial power shortage of the power grid.

[0012] Further, the expression of the comprehensive energy inertia support model considering the combined output of gas and heat inertia is:

[0013] P s (t0+t delay )=ε1[P h,in (t0)+ΔP h,in ]+ε2[P h,in (t0)+ΔP h,in ]

[0014] In the formula, P h,in is the heat power supplied by the heat source to the heat network at t0, ΔP h,in is the power fluctuation generated at the heat source at t0; P s (t0+t delay ) is the total power of the comprehensive energy gas and heat inertia support, ε1 and ε2 are the damping coefficient constants of the heat inertia and the gas inertia for responding to the power fluctuation, and 0<ε1,ε2<1, t delay is the power fluctuation transmission delay time.

[0015] Further, in S2, the steps for establishing the comprehensive energy gas and heat inertia support optimization model considering the natural gas network constraint are:

[0016] S21, a natural gas network model considering the location of the park-level comprehensive energy system load group is established, taking into account the natural gas network node pressure constraint, pipeline flow constraint, gas pipe storage constraint and node flow constraint;

[0017] S22, the comprehensive energy gas and heat inertia support optimization model considering the natural gas network constraint is established based on the natural gas network model considering the location of the park-level comprehensive energy system load group established in S21, considering the combined output of gas and heat inertia.

[0018] Further, the expression of the natural gas network model considering the location of the park-level comprehensive energy system load group established in S21 is:

[0019]

[0020] In the formula, ρ0 is the natural gas density under standard conditions, Lmn and Dmn are respectively the length and diameter of the natural gas pipeline mn, is the gas pipe storage in the pipeline at t, T G is the natural gas temperature, R M is the ratio of the gas constant to the molar mass, Z is the natural gas compression coefficient, is the average pressure in the natural gas pipeline, Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and 2, Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and Qm and Qn are the flow at the beginning and end of the pipeline mn at time t respectively, Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and Qm and Qn are the flow at the beginning and end of the pipeline mn at time t respectively, Qm and Qn are the flow at the beginning and end of the pipeline mn at time t respectively,

[0021] Further, the objective function of the comprehensive energy gas-thermal inertia support optimization model considering the constraints of the natural gas network established in S22 is:

[0022]

[0023] In the formula, Cost is the total inertia support cost, C RG Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and n Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and n Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and c Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and n Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and c Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and c Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and c Pm and Pn are the node pressure at natural gas network nodes m and n respectively, and

[0024] Further, in S3, the specific steps of establishing the comprehensive energy gas-thermal inertia support optimization model considering the simplified conditions of the complex constraints of the natural gas network are:

[0025] S31, based on S2, the natural gas network constraint is considered in the comprehensive energy gas heat inertia support model, the node pressure constraint, the pipeline flow constraint, the gas pipe storage constraint and the node flow constraint are simplified, and the comprehensive energy gas heat inertia support optimization model considering the reasonable simplification of the natural gas network constraint is established:

[0026] S32, the inertia support model optimization result considering / without considering the natural gas network constraint, the comprehensive energy gas heat inertia support model considering the natural gas network constraint established based on S2 and the comprehensive energy gas heat inertia support optimization model considering the reasonable simplification of the natural gas network constraint established in step S31, the comprehensive energy inertia support comparison model considering / without considering the natural gas network constraint is established;

[0027] S33, based on the optimization result of the comprehensive energy inertia support comparison model considering / without considering the natural gas network constraint established in S32, the comprehensive energy gas heat inertia support model considering the simplification condition of the natural gas network complex constraint is established.

[0028] Further, in S31, the comprehensive energy gas heat inertia support optimization model considering the reasonable simplification of the natural gas network constraint is as follows:

[0029]

[0030] In the formula, Cost simp is the total cost of the inertia support after the simplification of the gas network, c RG is the unit price of the gas inertia output after considering the simplification of the gas network constraint, c RG is the total gas inertia output after considering the simplification of the gas network constraint.

[0031] Further, in S32, the expression of the comprehensive energy inertia support comparison model considering / without considering the natural gas network constraint is as follows:

[0032]

[0033] In the formula, dCost is the difference between the total inertia support costs considering / without considering the gas network constraint, Cost is the total inertia support cost considering the gas network constraint, Cost simp is the total inertia support cost without considering the gas network constraint; dP RG is the difference between the gas inertia outputs considering / without considering the gas network constraint, P RG is the gas inertia output considering the gas network constraint, P RGsim is the gas inertia output without considering the gas network constraint; is the difference between the heat inertia outputs from the load group n considering / without considering the gas network constraint, is the heat inertia output considering the gas network constraint, is the heat inertia output without considering the gas network constraint.

[0034] Further, in S33, the expression of the comprehensive energy gas-thermal inertia support model considering the simplified conditions of the complex constraints of the natural gas network is:

[0035]

[0036]

[0037]

[0038] In the formula, P turning is the power turning point corresponding to the upper limit of the thermal inertia output, P shortage is the initial power shortage of the power grid, Cost final , P RG，final and final are the final value of the inertia support total cost, the final value of the gas inertia output, and the final value of the thermal inertia output from the load group n, respectively.

[0039] A computer storage medium stores a readable program, when the program is executed, the method described above is executed.

[0040] The beneficial effects of the present application are: the support of the thermal inertia characteristics of the thermal system and the gas inertia characteristics of the natural gas system on power failure is clarified, and the influence of the location of the fault point in the natural gas pipeline network on the gas inertia output is fully considered, so as to evaluate the influence of the location of the fault point on the response capability of the comprehensive energy system after failure; the evaluation of the response capability of the comprehensive energy system after failure can further optimize the existing multi-energy inertia support method, so as to ensure the practical value of the proposed comprehensive energy inertia support method in engineering application, provide a new idea for formulating an output scheme for the comprehensive energy system to cope with subsequent failures, and ensure the reliable operation of the system. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows, and obviously, other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0042] Figure 1 is the total flow chart of the method of the present application;

[0043] Figure 2 is the thermal inertia characteristic diagram of the comprehensive energy system;

[0044] Figure 3 is the gas inertia characteristic diagram of the comprehensive energy system;

[0045] Figure 4 is a simplified 8-node network schematic diagram;

[0046] Figure 5 Fig. 1 is a diagram of comparative model optimization results of integrated energy inertia support considering / without considering natural gas network constraints (a fault occurs at load group 1);

[0047] Figure 6 Fig. 2 is a diagram of comparative model optimization results of integrated energy inertia support considering / without considering natural gas network constraints (a fault occurs at load group 2);

[0048] Figure 7 Fig. 3 is a diagram of comparative model optimization results of integrated energy inertia support considering / without considering natural gas network constraints (a fault occurs at load group 3);

[0049] Figure 8 Fig. 4 is a model curve diagram of a thermal inertia output upper limit and a power turning point. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0051] As shown in FIG. 1, a method of integrated energy inertia support considering reasonable simplification of gas network constraints includes the following steps: Figure 1

[0052] S1, considering the similarity of the forms of thermal inertia and gas inertia output of an integrated energy system, an integrated energy inertia support model considering joint output of gas and thermal inertia is established:

[0053] As shown in FIG. 2, the thermal inertia of an integrated energy system mainly manifests as: power fluctuation transmission delay and heat loss caused by a long hot water transmission pipeline; and the influence of load fluctuation at a heat source on a heat network load is further reduced due to the certain tolerance range of the load side to temperature fluctuation. Figure 2 As shown in FIG. 3, the gas inertia of an integrated energy system mainly manifests as: the delay response time of a natural gas system to demand change caused by the long distance between a gas source and a gas source load and the gas pipe storage characteristics that can meet the instantaneous load demand change.

[0054] Figure 3 Therefore, under a power shortage scenario, the integrated energy inertia support considering joint output of gas and thermal inertia is expressed as follows:

[0055]

[0056]

[0057] ​​​In the formula, P h,out (t0+t h,delay ) is t0+t h,delay Heat power on the load side of the heating network at any given time, P h,in The heat output of the heat source to the heating network at time t0, t h,delay ΔP is the time delay in the transfer of heat power from the heat source to the load side. h,in P represents the power fluctuation generated at the heat source at time t0. g,out (t0+t g,delay ) is t0+t g,delay The power of the gas supply to the load at any given time, P g,in The power supplied by the gas source to the load at time t0, t g,delay ΔP represents the delayed response time of the natural gas system to changes in demand. g,in P represents the demand fluctuation at the load at time t0. s (t0+t delay ) represents the total power supported by the combined energy gas thermal inertia, and ε1 and ε2 are the constants of the thermal inertia and gas inertia in response to power fluctuations, respectively, with 0 < ε1 and ε2 < 1; ε1 and ε2 characterize the ability of gas thermal inertia to suppress power fluctuations, t delay This refers to the power fluctuation transmission delay time.

[0058] S2, considering the natural gas network constraints including node pressure constraints, pipeline flow constraints, gas pipeline storage constraints and node flow constraints, and based on the integrated energy inertia support model of gas-heat inertia joint output in S1, establish an integrated energy gas-heat inertia support optimization model considering natural gas network constraints.

[0059] The specific steps include:

[0060] S21, taking into account the pressure constraints of natural gas network nodes, pipeline flow constraints, gas storage constraints, and node flow constraints, a natural gas network model considering the location of load groups in the park-level integrated energy system is established.

[0061] like Figure 4 As shown, a natural gas network model is established based on a simplified 8-node natural gas network. The network considers two natural gas sources and three differently distributed load groups, each load group being connected to its own combined heat and power (CHP) unit. The modeling of natural gas compressors is not considered in the network modeling process. Then, considering the location of load groups in the integrated energy system at the park level, the natural gas network model taking into account node pressure, pipeline flow rate, and gas storage constraints is expressed as follows:

[0062]

[0063] In the formula, ρ0 is the density of natural gas under standard conditions. respectively the length and diameter of the natural gas pipeline mn, is the gas storage in the pipeline at time t, G is the temperature of the natural gas, M is the ratio of the gas constant to the molar mass, and Z is the compressibility factor of the natural gas, is the average pressure in the natural gas pipeline, respectively the node pressure at nodes m and n of the natural gas network, then is expressed as 2, is the gas storage in the pipeline at time t-1, respectively the flow rate at the beginning and end of the pipeline mn at time t, is the pressure of the natural gas under standard conditions; is the temperature of the natural gas under standard conditions; is the compressibility factor of the natural gas under standard conditions, is the flow rate of the natural gas in the pipeline mn, and λ is the pipeline friction coefficient, is the average flow rate in the pipeline, expressed as

[0064] Next, consider the network node flow constraints; the node flow constraints of natural gas are similar to those of electricity, and follow the principle that the total inflow flow at the node is equal to the total outflow flow; the flow of natural gas at the load is consistent with the change of the load, and only changes when the load demand changes; then the node flow constraint expression in the natural gas network model considering the location of the load group of the park-level integrated energy system is as follows:

[0065]

[0066] In the formula, respectively the flow rate at the beginning and end of the pipeline mn at time t, is the flow rate of the natural gas at the load group n at time t; if the fault occurs at the load group L1, then changes while remains unchanged; if the fault occurs at the load group L2, then changes together with while remains unchanged; if the fault occurs at the load group L3, then changes together with while remains unchanged.

[0067] S22, considering the gas-thermal inertia combined output, based on the natural gas network model considering the location of the load group of the park-level integrated energy system established in S21, an integrated energy gas-thermal inertia support optimization model considering the natural gas network constraint is established;

[0068] In the park-level integrated energy system, considering the combined output of gas and heat inertia, under the premise of ensuring the safe operation of the system, the minimum total cost of integrated energy inertia support in the power shortage scenario is taken as the optimization objective, the heat inertia output and the gas inertia output are considered, the influence of single fault point on the overall gas inertia output of the natural gas network is considered, an integrated energy gas and heat inertia support optimization model considering user comfort cost is established, the objective function of the model is as follows, including the total cost of gas inertia output, the total cost of heat inertia output and the user comfort cost:

[0069]

[0070] In the formula, Cost is the total inertia support cost, C RG is the total cost of gas inertia output,

[0071] is the total cost of heat inertia output, is the user comfort cost; T is the fault duration, t0 is the initial time of fault occurrence, is the unit cost of gas pipe storage in pipe a(a+1) and pipe (b+1)(b+2) when the fault occurs in load group L n (a=1,2,3; b=4,5), is the unit cost of gas pipe storage in pipe 36 when the fault occurs in load group L n ; is the unit cost of heat inertia output when the fault occurs in load group L c (c,n=1,2,3), is the unit cost of load group L n (c=1,2,3) at m level when the fault occurs in load group L c ; is the heat inertia output power of load group L c (c=1,2,3) at t time; is the heat offset at m level of load group L c (c=1,2,3) at t time; the user comfort cost adopts step price, M is the total number of comfort cost price steps, C is the total number of load groups in the network (C=3).

[0072] S3, based on the integrated energy gas and heat inertia support optimization model considering the constraints of natural gas network established in S2, the constraints of natural gas network are simplified, and an integrated energy gas and heat inertia support optimization model considering the simplified conditions of complex constraints of natural gas network is established.

[0073] The specific steps are as follows:

[0074] S31, based on the S22 established considering natural gas network constraint comprehensive energy gas heat inertia support model, simplify node pressure constraint, pipeline flow constraint, gas pipe storage constraint, node flow constraint, establish considering natural gas network constraint reasonable simplification comprehensive energy gas heat inertia support optimization model:

[0075] In the comprehensive energy inertia support method, due to considering the natural gas network constraint, the unit price of gas inertia output and heat inertia output is different, and the formulation of the output unit price mainly depends on the location of the output source in the network. After considering the reasonable simplification of the natural gas network constraint, the gas inertia output unit price will be regarded as a constant value, and the heat inertia output unit price will not be significantly increased. The modeling complexity of the optimization model is not changed, so the heat inertia output unit price remains unchanged; under the premise of ensuring the safe operation of the system, the gas inertia output and heat inertia output are combined to minimize the inertia support cost as the optimization objective, and the comprehensive energy gas heat inertia support optimization model considering the reasonable simplification of the natural gas network constraint is established as follows:

[0076]

[0077] In the formula, Cost simp is the inertia support total cost of the simplified gas network, c RG is the gas inertia output unit price considering the simplified gas network constraint, c RG is the total gas inertia output considering the simplified gas network constraint.

[0078] S32, considering the inertia support model optimization result considering / not considering the natural gas network constraint, based on the S2 established considering natural gas network constraint comprehensive energy gas heat inertia support model and the step S31 established considering natural gas network constraint reasonable simplification comprehensive energy gas heat inertia support optimization model, the comprehensive energy inertia support comparison model considering / not considering the natural gas network constraint is established; specifically:

[0079] Based on the S2 established considering natural gas network constraint comprehensive energy gas heat inertia support model and the S31 established considering natural gas network constraint reasonable simplification comprehensive energy gas heat inertia support optimization model, the optimization results obtained by the two models are subtracted, and the differences between the optimization results obtained by the two models in terms of inertia support total cost and gas inertia, heat inertia output are compared, and the influence of not considering the gas network constraint on the calculation accuracy of the optimization model is obtained; therefore, the comprehensive energy inertia support comparison model considering / not considering the natural gas network constraint is expressed as follows, by analyzing the size of dCost, dP RG and :

[0080]

[0081] wherein, dCost is the difference of total inertial support cost with / without considering gas network constraints, Cost is the total inertial support cost with considering gas network constraints, Cost simp is the total inertial support cost without considering gas network constraints; dP RG is the difference of gas inertial output with / without considering gas network constraints, P RG is the gas inertial output with considering gas network constraints, P RGsim is the gas inertial output without considering gas network constraints; is the difference of thermal inertial output from load group n with / without considering gas network constraints, is the thermal inertial output with considering gas network constraints, is the thermal inertial output without considering gas network constraints.

[0082] The model optimization results are shown in Figures 5-7 ; Figures 5-7 The total inertial support cost, gas inertial output and thermal inertial output with / without considering gas network constraints when the fault occurs in load group 1, load group 2 and load group 3 respectively are shown in

[0083] Figure 5 (a), Figure 6 (a) and 7(a) evaluate the economy of inertial support cost by giving the total cost with / without considering gas network constraints under different power shortage conditions; in general, the total cost with considering gas network constraints is higher than that without considering gas network constraints under different power shortage conditions; the main reason is that the gas inertial output price without considering gas network constraints is the lowest among the various gas inertial output prices with considering gas network constraints under the condition that the unit prices of other output forms are the same; however, there is a turning point on the total cost difference curve; no matter how the power shortage degree is before the turning point, the total cost difference is constant, but it increases with the increase of power shortage after the turning point;

[0084] From Figure 5 (b), Figure 6 (b) and 7(b) can easily find that there is a turning point on the gas inertial output difference curve; before the turning point, there is fluctuation difference in the gas inertial output with / without considering gas network constraints, and after the turning point, it is zero no matter how the power shortage is; Figure 5 (c), Figure 6 (c) and 7(c) show the thermal inertial output difference from the three load groups; except that the thermal inertial output at the fault point is the same with / without considering gas network constraints, the thermal inertial output difference is zero after the turning point.

[0085] It is worth noting that all the turning points are at the same power shortage of 370 (kWh / s), which is not a coincidence; by observing the power output scale and total cost before and after the turning point, the following phenomena can be explained: 1) The unit price of thermal inertia output is lower than that of gas inertia; under the premise of not affecting the comfort of users, the inertia support optimization model always prefers to call thermal inertia output until the thermal inertia output reaches the upper limit. 2) Before the turning point, the power shortage of the power grid is not very large, and the optimization model considering the gas network is not constrained by the upper limit of thermal inertia output, and can always flexibly use more thermal inertia output to avoid high gas inertia cost. 3) After the turning point, the thermal inertia output considering / without considering the gas network constraint reaches the upper limit, and the optimization flexibility is constrained. Therefore, as the power shortage increases, the difference between the total cost of the support considering / without considering the gas network constraint also increases. Therefore, the condition for determining whether the gas network constraint can be simplified is the size relationship between the initial power shortage of the power grid and the power turning point corresponding to the upper limit of the thermal inertia output of the integrated energy system.

[0086] S33, based on the optimization results of the integrated energy inertia support comparison model considering / without considering the natural gas network constraint established in S32, an integrated energy gas-thermal inertia support model considering the simplified condition of the complex constraint of the natural gas network is established:

[0087] Based on the analysis of the optimization results of the integrated energy inertia support comparison model considering / without considering the natural gas network constraint established in S32, it is found that for a park-level integrated energy system with a fixed upper limit of thermal inertia output, whether the natural gas network constraint can be simplified in the integrated energy gas-thermal inertia support model is determined by the size relationship between the initial power shortage of the power grid and the upper limit of the thermal inertia output. It is considered that the upper limit of the thermal inertia output of the integrated energy system corresponds to a power turning point P turning , then compare the relationship between a certain initial power shortage P shortage and P turning : if P shortage is less than or equal to P turning , the gas network constraint can be simplified to obtain a rough estimate of the total cost of inertia support under the size of the power shortage; if P shortage is greater than P turning , the gas network constraint can be simplified to obtain a rough estimate of the gas inertia output and the thermal inertia output under the size of the power shortage; therefore, the integrated energy gas-thermal inertia support model considering the simplified condition of the complex constraint of the natural gas network is expressed as follows:

[0088]

[0089]

[0090]

[0091] In the formula, Pturning P shortage is the initial power shortage of the power grid, Cost final , P RG，final is the power turning point corresponding to the upper limit of thermal inertia output are the final value of the total cost of inertia support, the final value of the gas inertia output and the final value of the thermal inertia output from the load group n, respectively.

[0092] S4, considering the relationship between the upper limit of thermal inertia output and the power turning point, based on the comprehensive energy gas-thermal inertia support model considering the simplified conditions of natural gas network complex constraints established in S33, a reasonable simplified inertia support model of gas network constraints suitable for engineering practice is established:

[0093] Based on the model established in S33, the decision condition for the simplified gas network constraints is the power turning point P turning of the upper limit of thermal inertia output of the comprehensive energy system; in a park-level comprehensive energy system, the upper limit of thermal inertia output is usually a known parameter, while the power turning point is an unknown parameter, so the upper limit of thermal inertia output of the comprehensive energy system is selected, and the corresponding power turning point is obtained through experiments, and a model of the upper limit of thermal inertia output and the power turning point is established, and the model curve is shown in Figure 8 . Therefore, under the premise that the upper limit of thermal inertia output of the park is known in actual engineering application, the corresponding power turning point P turning can be obtained by using the model curve, and compared with the initial fault power shortage P shortage of the power grid to determine the feasibility of the simplified gas network. Therefore, the reasonable simplified inertia support model of gas network constraints suitable for engineering practice is expressed as follows:

[0094] P shortage = σ1P turning + σ2

[0095] In the formula, σ1 and σ2 are coefficient constants, and the specific values depend on the upper limit of thermal inertia output of the comprehensive energy system.

[0096] In the description of the present specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0097] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A comprehensive energy inertia support method considering reasonable simplification of gas network constraints, characterized in that, The method comprises the following steps: S1, considering the similarity of the thermal inertia and gas inertia output forms of the integrated energy system, an integrated energy inertia support model considering the combined output of the gas thermal inertia is established; S2, considering the natural gas network constraint, and based on the integrated energy inertia support model considering the combined output of the gas thermal inertia, an integrated energy gas thermal inertia support optimization model considering the natural gas network constraint is established; S3, based on the integrated energy gas thermal inertia support optimization model considering the natural gas network constraint, the natural gas network constraint is simplified, and an integrated energy gas thermal inertia support optimization model considering the simplified condition of the complex constraint of the natural gas network is established; S4, considering the relationship between the upper limit of the thermal inertia output and the power turning point, and based on the integrated energy gas thermal inertia support model considering the simplified condition of the complex constraint of the natural gas network, an inertia support model suitable for engineering practice is established; wherein is the power turning point corresponding to the upper limit of thermal inertia output, is the initial power shortage of the power grid, and is a coefficient constant; In S3, the specific steps of establishing the integrated energy gas thermal inertia support optimization model considering the simplified condition of the complex constraint of the natural gas network are as follows: S31, based on the integrated energy gas thermal inertia support model considering the natural gas network constraint established in S2, the node pressure constraint, the pipeline flow constraint, the gas pipe storage constraint and the node flow constraint are simplified, and an integrated energy gas thermal inertia support optimization model considering the reasonable simplification of the natural gas network constraint is established; S32, considering the optimization results of the inertia support model with / without considering the natural gas network constraint, based on the integrated energy gas thermal inertia support model considering the natural gas network constraint established in S2 and the integrated energy gas thermal inertia support optimization model considering the reasonable simplification of the natural gas network constraint established in step S31, an integrated energy inertia support comparison model considering / without considering the natural gas network constraint is established; S33, based on the optimization results of the integrated energy inertia support comparison model considering / without considering the natural gas network constraint established in S32, the integrated energy gas thermal inertia support model considering the simplified condition of the complex constraint of the natural gas network is established; In S31, the integrated energy gas thermal inertia support optimization model considering the reasonable simplification of the natural gas network constraint is as follows: wherein, is the total cost of the simplified inertial support of the gas network, is the simplified gas inertial output unit price taking into account the constraints of the gas network. In S32, the expression of the integrated energy inertia support comparison model considering / without considering the natural gas network constraint is as follows: wherein, the difference between the total inertia support cost with / without considering the gas network constraint, the total inertia support cost with considering the gas network constraint, the total inertia support cost without considering the gas network constraint; the difference between the gas inertia output with / without considering the gas network constraint, the gas inertia output with considering the gas network constraint, the gas inertia output without considering the gas network constraint; the difference between the thermal inertia output from the load group with / without considering the gas network constraint, the thermal inertia output with considering the gas network constraint, the thermal inertia output without considering the gas network constraint; In S33, the expression of the comprehensive energy gas-heat inertia support model considering the simplified conditions of the complex constraints of the natural gas network is: wherein is the power break point corresponding to the upper limit of thermal inertia output, is the initial power deficit of the grid, , and are the final value of the total cost of inertia support, the final value of aerodynamic inertia output and the final value of thermal inertia output from the load group , respectively.

2. The method of claim 1, wherein, The expression of the integrated energy inertia support model considering the combined output of the gas thermal inertia is as follows: wherein, is the thermal power supplied by the heat source to the heat network at time t, is the thermal power supplied by the heat source to the heat network at time t, is the delay time of the thermal power transmission from the heat source to the load side, is the power fluctuation generated at the heat source at time t; is the power supplied by the gas source to the load at time t, is the power supplied by the gas source to the load at time t, is the delay response time of the natural gas system to the demand change, is the demand fluctuation generated at the load at time t; is the total power supported by the comprehensive energy gas-heat inertia, and are respectively the smoothing coefficient constants of the heat inertia and the gas inertia to respond to the power fluctuation, and ; and characterize the smoothing ability of the gas-heat inertia to respond to the power fluctuation, is the power fluctuation transmission delay time.

3. The method of claim 1, wherein, In S2, the steps of establishing the integrated energy gas thermal inertia support optimization model considering the natural gas network constraint are as follows: S21, the node pressure constraint, the pipeline flow constraint, the gas pipe storage constraint and the node flow constraint are considered, and a natural gas network model considering the position of the park-level integrated energy system load group is established; S22, considering the combined output of the gas thermal inertia, based on the natural gas network model considering the position of the park-level integrated energy system load group established in S21, an integrated energy gas thermal inertia support optimization model considering the natural gas network constraint is established.

4. The method of claim 3, wherein, In S21, the node pressure constraint, the pipeline flow constraint and the gas pipe storage constraint are considered, and the expression of the natural gas network model considering the position of the park-level integrated energy system load group is as follows: In the formula, The density of natural gas under standard conditions. Natural gas pipelines Length and diameter, for There is always air in the pipeline. For natural gas temperature, This is the ratio of the gas constant to the molar mass. The compressibility coefficient of natural gas. This represents the average pressure inside the natural gas pipeline. Let m and n be the pressures at nodes m and n in the natural gas network, respectively. Represented as , for The air in the pipeline must be present at all times. They are respectively Time Pipeline Head End-point flow, This refers to the pressure of natural gas under standard conditions. The temperature of natural gas under standard conditions; The compressibility coefficient of natural gas under standard conditions. For pipelines Natural gas flow rate inside, The coefficient of friction of the pipeline. The average flow rate within the pipe is expressed as... .

5. The method of claim 3, wherein, In S22, the objective function of the integrated energy gas thermal inertia support optimization model considering the natural gas network constraint is as follows: In the formula, For inertial support total cost, Total cost of inertial force output. Total cost of thermal inertia output For user comfort costs; T is the duration of the fault. It is the initial moment when the fault occurs; The fault occurred in the load group The unit cost of thermal inertia output (c, n = 1, 2, 3) The fault occurred in the load group Load group at time Demand-side efforts Unit cost at the level ( )yes Time-based load group Thermal inertia output power; ( )yes Time-based load group In Thermal offset at horizontal levels; user comfort cost adopts tiered pricing, where M is the total number of tiers for comfort cost pricing and C is the total number of load groups in the network.

6. A computer storage medium storing a readable program, characterized in that, When the program is running, the method of any one of claims 1-5 is executed.

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