A Method for Constructing a Dynamic Safety Region of a Natural Gas Pipeline Network for Peak Shaving of Gas Turbine Units

Abstract

The present invention proposes a method for constructing a dynamic safety region of a natural gas pipeline network for peak shaving of gas turbine units. The present invention sets a time-domain dynamic observation window and divides it into multiple sub-periods; sets the search direction of the injection space of the dynamic safety region of the natural gas pipeline network for peak shaving of gas turbine units, and calculates the growth direction of the gas load mass flow rate of the corresponding gas turbine units; establishes a boundary search optimization model with the maximization of the safety margin in the growth direction as the objective and discrete dynamic pipe flow safety constraints as the core constraint conditions; calculates a critical point in the search direction of the injection space of the dynamic safety region of the natural gas pipeline network for peak shaving of gas turbine units; and constructs the dynamic safety region of the natural gas pipeline network for peak shaving of gas turbine units through piecewise linear fitting. The present invention helps to achieve the dynamic safety and rapid assessment of the natural gas pipeline network, assist in supporting power grid dispatching decisions and optimal control, and improve the collaborative risk control ability of the power grid and the natural gas pipeline network under deep coupling of heterogeneous energy flows.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated energy systems, and particularly relates to a method for constructing a dynamic safety domain of a natural gas pipeline network for peak shaving of gas turbines. Background Art

[0002] The flexible peak shaving ability of gas turbines can effectively alleviate the impact of the output fluctuations of a high proportion of renewable energy power generation in the power grid on the safe operation of the power grid. However, it will cause severe fluctuations in the net load of the natural gas pipeline network, which may cause instantaneous pressure safety limits. This will not only shorten the service life of the pipeline, but also may cause natural gas leakage accidents. In addition, due to the strict requirements of gas turbines for the inlet pressure range, being higher or lower than the pressure range will threaten the safe operation of gas turbines and even cause shutdown accidents. Therefore, when the power grid conducts peak shaving scheduling of gas turbines without perceiving the operating state and safety risk situation of the natural gas pipeline network, it may threaten the safe operation of the natural gas pipeline network and the gas turbines themselves, and even trigger cascading failures between the power-gas interconnected systems.

[0003] In the energy system, the safety domain theory is a powerful tool for guiding online safety assessment and control under strong stochastic volatility. The safety domain theory describes the operating point range that satisfies the safe and stable operation of the power-gas interconnected system from the perspective of the "domain". The relative relationship between the system operating point and the safety domain boundary can provide safety margin information, which provides strong support for realizing online real-time safety monitoring, defense and control of the power-gas interconnected system. However, the existing natural gas pipeline network safety domain models are all established based on the steady-state pipe flow model, and it is difficult to reflect the impact of the output change of gas turbines on the dynamic pipe flow safety of the natural gas network. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention proposes a method for constructing a dynamic safety domain of a natural gas pipeline network for peak shaving of gas turbines, and the specific steps are as follows:

[0005] Step 1: Set the time-domain dynamic observation window of the decision variables in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbines, and divide the time-domain dynamic observation window of the decision variables into multiple sub-periods;

[0006] Step 2: Set the search direction of the injection space of the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbines, and obtain the time-varying function of the gas load mass flow rate of the gas turbine in combination with the energy conversion relationship of the gas turbine; discretize the time-varying function of the gas load mass flow rate of the gas turbine through the space-time orthogonal collocation method in combination with multiple sub-periods in sequence, and obtain the growth direction of the gas load mass flow rate of the gas turbine corresponding to the search direction of the injection space of the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbines;

[0007] Step 3: Taking the gas source mass flow rate, pipeline inlet mass flow rate, pipeline outlet mass flow rate, pipeline mass flow rate, pipeline pressure along the line, booster station inlet pressure, booster station outlet pressure, booster station inlet mass flow rate, booster station outlet mass flow rate, and booster station gas consumption as decision variables, discretizing the decision variables for each sub-period in turn through the space-time orthogonal collocation method, constructing an optimization objective with the maximum safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit corresponding to the search direction of the injection space of the dynamic safety domain of the natural gas pipeline network for gas turbine unit peak shaving obtained in Step 2, constructing constraint conditions in combination with the decision variables of each sub-period, and optimizing and solving through the simplex method optimization algorithm to obtain the optimized decision variables for each sub-period and the safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit;

[0008] Step 4: Obtaining the maximum safety margin in the growth direction of the gas turbine unit peak shaving strategy based on the safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit and the energy conversion relationship of the gas turbine unit; furthermore, obtaining the critical point of the dynamic safety domain of the natural gas pipeline network for gas turbine unit peak shaving based on the growth direction of the gas turbine unit peak shaving strategy and the maximum safety margin in the growth direction of the gas turbine unit peak shaving strategy;

[0009] Step 5: Traversing each direction of the injection space of the dynamic safety domain of the natural gas pipeline network for gas turbine unit peak shaving, and sequentially executing Steps 2 - 4 to obtain the critical points of each direction of the injection space of the dynamic safety domain of the natural gas pipeline network for gas turbine unit peak shaving;

[0010] Step 6: Combining the critical points of each direction of the injection space of the dynamic safety domain of the natural gas pipeline network for gas turbine unit peak shaving, further constructing the boundary of the dynamic safety domain of the natural gas pipeline network for gas turbine unit peak shaving through the piecewise linear fitting method, and taking the area within the boundary of the dynamic safety domain of the natural gas pipeline network for gas turbine unit peak shaving as the safety domain for realizing the dynamic safety assessment of the natural gas pipeline network and assisting in supporting the grid dispatching decision-making and optimal control.

[0011] Preferably, the time-domain dynamic observation window of the decision variables in the dynamic safety domain of the natural gas pipeline network for gas turbine unit peak shaving shown in Step 1 is defined as:

[0012] [t0, t N

[0013] wherein, t0 represents the initial moment of the time-domain dynamic observation window, and t N represents the termination moment of the time-domain dynamic observation window;

[0014] The specific method for dividing the time-domain dynamic observation window of the decision variables described in Step 1 into multiple sub-periods is as follows:

[0015] ​Select multiple time-domain segmentation points in the time-domain dynamic observation window of the decision variables in the dynamic safety domain of the natural gas pipeline network for the peak shaving of gas turbines according to the real-time scheduling interval of the power grid, which is specifically defined as: t0, t1, …, t s , …, t N ;

[0016] Among them, t s represents the s-th time-domain segmentation point, and N + 1 represents the number of time-domain segmentation points;

[0017] The multiple sub-time periods are defined as:

[0018] [t0, t1], [t1, t2], …, [t s-1 , t s , …, [t N-1 , t N

[0019] Among them, [t s-1 , t s represents the s-th sub-time period;

[0020] Preferably, the search direction of the injection space of the dynamic safety domain of the natural gas pipeline network for the peak shaving of gas turbines described in step 2 is specifically:

[0021]

[0022] Among them, is the active power adjustment strategy of the i-th gas turbine in the s-th sub-time period;

[0023] The energy conversion relationship of the gas turbine described in step 2 is the energy conversion relationship between the active power of the gas turbine and the mass flow rate of the gas load at the intake port of the gas turbine, which is specifically:

[0024]

[0025] Among them, f La,i,s is the mass flow rate of the gas load consumed by the i-th gas turbine in the s-th sub-time period; t is the time variable; t s is the execution time of the peak shaving scheduling of the gas turbine; is the active power adjustment strategy of the i-th gas turbine in the s-th sub-time period; is the rated power of the i-th gas turbine; is the maximum ramp rate of the i-th gas turbine; η 0i is the constant term energy consumption coefficient of the i-th gas turbine; η 1i is the first-order term energy consumption coefficient of the i-th gas turbine;

[0026] The time function of the mass flow rate of the gas load of the gas turbine described in step 2, the specific calculation formula is:​

[0027]

[0028] where t is a time variable; f La,i is the mass flow rate of natural gas consumed by the i-th gas turbine unit; is the mass flow rate of natural gas consumed by the i-th gas turbine unit at the initial moment of the time-domain dynamic observation window; df La,i,s is the change in the mass flow rate of gas load caused by the adjustment strategy of the i-th gas turbine unit in the s-th sub-period;

[0029] The discretization of the time-varying function of the gas load mass flow rate of the gas turbine unit by the spatio-temporal orthogonal collocation method in combination with multiple sub-periods described in step 2 is specifically as follows:

[0030]

[0031] where df La,i,s is the change in the mass flow rate of gas load caused by the adjustment strategy of the i-th gas turbine unit in the s-th sub-period; l j (τ) is the basis function of the j-th order Lagrange univariate interpolation polynomial; N t is the number of time collocation points in the spatio-temporal orthogonal collocation method; τ is the dimensionless time coordinate; is the component of the growth direction of the gas load mass flow rate of the gas turbine unit after discretization at the j-th time collocation point in the s-th sub-period;

[0032] The growth direction of the gas load mass flow rate of the gas turbine unit corresponding to the search direction of the injection space of the dynamic safety domain of the natural gas pipeline network for peak shaving of the gas turbine unit obtained in step 2 is specifically as follows:

[0033]

[0034] Preferably, the optimization objective constructed in step 3 is specifically defined as follows:

[0035] maxφ Fl

[0036] where φ Fl is the safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit, and max represents maximization;

[0037] The constraint conditions are constructed by combining the decision variables of each sub-period in step 3 as follows:

[0038] The constraint conditions are composed of the total gas load mass flow rate constraint, the gas load mass flow rate constraint of gas turbine units, the node flow balance equation constraint, the discrete partial differential equation constraint of the dynamic pipeline flow in the natural gas pipeline network, the compressor operation constraint, the initial boundary conditions of the dynamic pipeline flow model, the dynamic pipeline flow safety constraint, and the association condition constraint between the decision variables of the nodes and pipelines in the natural gas pipeline network;

[0039] The total gas load mass flow rate constraint is specifically:

[0040]

[0041] where, is the component of the total gas load mass flow rate at node m at the time configuration point j in the s-th sub-time period; is the component of the gas load mass flow rate of the gas turbine unit at node m at the time configuration point j in the s-th sub-time period; is the predicted value of the component of the conventional gas load mass flow rate at node m at the time configuration point j in the s-th sub-time period; γ is the set of nodes in the natural gas system; N t is the number of time configuration points in the space-time orthogonal collocation method; N is the number of segments of the time domain dynamic observation window of the state variables;

[0042] The gas load mass flow rate constraint of the gas turbine unit is specifically:

[0043]

[0044] where, is the component of the gas load mass flow rate of the gas turbine unit at node m at the time configuration point j in the s-th sub-time period; is the gas load mass flow rate of the gas source at node m at the initial moment t of the s-th sub-time period s-1 ; φ Fl is the safety margin in the growth direction of the given gas load mass flow rate of the gas turbine unit; is the component of the growth direction of the given gas load mass flow rate of the gas turbine unit at node m at the time configuration point j in the s-th sub-time period; γ is the set of nodes in the natural gas system; N t is the number of time configuration points in the space-time orthogonal collocation method; N is the number of segments of the time domain dynamic observation window of the state variables;

[0045] The node flow balance equation constraint is specifically:

[0046]

[0047] where, is the component of the gas source mass flow rate at node m at the time configuration point j in the s-th sub-time period; is the component of the total gas load mass flow rate at node m at the time configuration point j in the s-th sub-period; is the value of the mass flow rate at the inlet node m of pipeline mn at the time configuration point j in the s-th sub-period; is the value of the mass flow rate at the outlet node n of pipeline nm at the time configuration point j in the s-th sub-period; γ is the set of nodes in the natural gas system; N t is the number of time configuration points in the space-time orthogonal collocation method; N is the number of segments of the time-domain dynamic observation window of the state variable;

[0048] The discrete partial differential equation constraint of the dynamic pipe flow of the natural gas pipeline network is specifically:

[0049]

[0050]

[0051] Among them, is the component of the mass flow rate of pipeline mn at the space-time configuration point (i, j) in the s-th sub-period; is the component of the pressure of pipeline mn at the space-time configuration point (i, j) in the s-th sub-period; is the first-order differential matrix in space The (i, z)-th element of, is the first-order differential matrix in time The (j, z)-th element of; A mn is the cross-sectional area of pipeline mn; D mn is the pipeline diameter of pipeline mn; L mn is the length of pipeline mn; v s is the gas sound speed of natural gas; Δt is the time length of the s-th sub-period; Δx mn is the length of pipeline mn; λ is the wall friction coefficient; is the average gas flow velocity of pipeline mn; X is the set of pipelines in the natural gas system; N t is the number of time configuration points in the space-time orthogonal collocation method; N x is the number of space configuration points in the space-time orthogonal collocation method; N is the number of segments of the time-domain dynamic observation window of the state variable;

[0052] The compressor operation constraint is specifically:

[0053]

[0054]

[0055]

[0056] Among them, The component of the outlet node pressure of pumping station mn at the time configuration point j in the s-th sub-period; is the component of the inlet node pressure of pumping station mn at the time configuration point j in the s-th sub-period; K Cmn is the pressure boost ratio of pumping station m'n'; is the component of the gas consumption of pumping station mn at the time configuration point j in the s-th sub-period; β mn is the gas consumption coefficient of pumping station mn; is the component of the mass flow rate at the outlet node of pumping station mn at the time configuration point j in the s-th sub-period; are respectively the components of the mass flow rate at the inlet node of pumping station mn at the time configuration point j in the sub-period; X C is the set of pipelines where the pumping stations in the natural gas system are located; N t is the number of time configuration points in the space-time orthogonal collocation method; N is the number of segments of the time-domain dynamic observation window of the state variable;

[0057] The initial boundary conditions of the dynamic pipe flow model are specifically:

[0058]

[0059]

[0060] Among them, is the initial value of the mass flow rate at the spatial collocation point i at the initial moment t of pipeline mn in the s-th sub-period s-1 ; is the initial value of the pressure at the spatial collocation point i at the initial moment t of pipeline mn in the s-th sub-period s-1 ; is the component of the mass flow rate of pipeline mn at the space-time collocation point (i, 0) in the s-th sub-period; is the component of the pressure of pipeline mn at the space-time collocation point (i, 0) in the s-th sub-period; X is the set of pipelines in the natural gas system; N x is the number of spatial collocation points in the space-time orthogonal collocation method; N is the number of segments of the time-domain dynamic observation window of the state variable;

[0061] The dynamic pipe flow safety constraints are specifically:

[0062]

[0063]

[0064]

[0065] Among them, is the component of the pressure at node m at the time configuration point j in the s-th sub-period; is the component of the mass flow rate of pipeline mn at the time-space configuration point (i, j) in the sth sub-period; is the component of the pressure of pipeline mn at the time-space configuration point (i, j) in the sth sub-period; p m is the safety lower limit of the pressure at node m; is the safety upper limit of the pressure on node m; p mn It is the safe lower limit of pipeline mn pressure; is the safety upper limit of pipeline mn pressure; f mn is the safe lower limit of the pipeline mn mass flow rate; is the safety upper limit of the mass flow rate of pipeline mn; γ is the set of nodes in the natural gas system; X is the set of pipelines in the natural gas system; N t N is the number of time collocation points in the time-space orthogonal collocation method; x is the number of spatial configuration points in the time-space orthogonal configuration method; N is the number of segments of the time-domain dynamic observation window of the state variable; the association condition constraints between the natural gas pipeline network nodes and the pipeline decision variables are specifically:

[0066]

[0067]

[0068]

[0069]

[0070] in, is the component of the mass flow rate of pipeline mn at the time-space configuration point (0, j) in the sth sub-period; is the value of the mass flow rate at the inlet node m of the pipeline mn at the time configuration point j in the sth sub-period; is the mass flow rate of pipeline mn at the time-space configuration point (N) in the sth sub-period x , the component at j); is the value of the mass flow rate at the inlet node m of the pipeline mn at the time configuration point j in the sth sub-period; is the value of the mass flow rate at the outlet node n of the pipeline mn at the time configuration point j in the sth sub-period; is the component of the pressure of pipeline mn at the time-space configuration point (0, j) in the sth sub-period; is the pressure of pipeline mn at the time and space configuration point (N x , the component at j); is the component of the pressure at node m at the time configuration point j in the sth sub-period; Nt is the number of time collocation points in the spatio-temporal orthogonal collocation method; N is the number of segments of the time-domain dynamic observation window of the state variable;

[0071] The safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit described in step 3 is the objective function value φ obtained by the optimization solution Fl ;

[0072] Preferably, the maximum safety margin in the growth direction of the peak shaving strategy of the gas turbine unit described in step 4 is specifically:

[0073] φ GPR = φ Fl

[0074] where φ GPR is the maximum safety margin in the growth direction of the peak shaving strategy of the gas turbine unit and is equal to the safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit when the energy conversion relationship of the gas turbine unit is a linear relationship;

[0075] The critical points of the dynamic safety domain of the natural gas pipeline network for peak shaving of the gas turbine unit described in step 4 are specifically as follows:

[0076]

[0077] where P SRB is a critical point of the dynamic safety domain of the natural gas pipeline network for peak shaving of the gas turbine unit, φ GPR is the maximum safety margin in the growth direction of the peak shaving strategy of the gas turbine unit, is the active power adjustment strategy of the i-th gas turbine unit in the s-th sub-time period.

[0078] Combined with engineering practice, the present invention has application potential in the dynamic safety rapid assessment of the natural gas pipeline network and the auxiliary support for power grid dispatching decision-making and optimal control, and helps to improve the collaborative risk control ability of the power grid and the natural gas pipeline network under the deep coupling of heterogeneous energy flows. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 : Schematic diagram of the method flow of the embodiment of the present invention;

[0080] Figure 2 : Schematic diagram of the reconstructed 20-node natural gas pipeline network in Belgium of the embodiment of the present invention;

[0081] Figure 3 : GPR-NDSR construction result diagram of the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0082] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0083] In specific implementation, the method proposed by the technical solution of the present invention can be automatically run by those skilled in the art using computer software technology. The system device for implementing the method, such as a computer-readable storage medium storing the corresponding computer program of the technical solution of the present invention and a computer device including the corresponding computer program running thereon, should also be within the protection scope of the present invention.

[0084] The following Figures 1 to 3 The technical solution of the method in the embodiment of the present invention is a method for constructing a dynamic safety domain of a natural gas pipeline for gas turbine peak shaving, which is specifically as follows:

[0085] As Figure 1 shown is a schematic flowchart of the method in the embodiment of the present invention.

[0086] The following takes the modified Belgian 20-node natural gas pipeline example as an example to further specifically illustrate the technical solution of the present invention. The wiring diagram of the modified Belgian 20-node natural gas pipeline example is as Figure 2 shown.

[0087] Taking the gas turbines G1 and G2 on nodes 6 and 7 in the modified Belgian 20-node natural gas pipeline example as the research objects, a GPR-NDSR is constructed. Let the reference power be 100MW, where the initial operating power of gas turbine G1 is 0.3pu and the maximum power output is 1pu, and the initial operating power of gas turbine G2 is 0.5pu and the maximum power output is 1.5pu.

[0088] Taking the active power adjustment strategies of gas turbine G1 at two stages at t0 = 0 and t1 = 15 min and the active power adjustment strategy of gas turbine G2 at t0 = 0 as the research objects, the GPR-NDSR characterizes the active power adjustment strategies ΔP of gas turbines of gas turbines that satisfy the dynamic safety of natural gas pipelines with the initial active power generation of gas turbines G1 and G2 as the reference and the active power adjustment amount of gas turbines G as the three-dimensional injection space.

[0089] Step 1: Set the time-domain dynamic observation window of the decision variables in the dynamic safety domain of the natural gas pipeline for gas turbine peak shaving, and divide the time-domain dynamic observation window of the decision variables into multiple sub-periods;

[0090] The time-domain dynamic observation window of the decision variables in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbines is defined as:

[0091] [t0, t N

[0092] where t0 = 0 represents the initial moment of the time-domain dynamic observation window, and t N = 30 represents the termination moment of the time-domain dynamic observation window;

[0093] The time-domain dynamic observation window of the decision variables described in Step 1 is divided into multiple sub-periods, specifically:

[0094] According to the real-time scheduling interval of the power grid, multiple time-domain segmentation points are selected in the time-domain dynamic observation window of the decision variables in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbines, specifically defined as: t0, t1,..., t s ,..., t N ;

[0095] where t s represents the s-th time-domain segmentation point, and N + 1 = 3 represents the number of time-domain segmentation points;

[0096] The multiple sub-periods are defined as:

[0097] [t0, t1], [t1, t2],..., [t s-1 , t s ,..., [t N-1 , t N

[0098] where [t s-1 , t s represents the s-th sub-period;

[0099] Step 2: Set the search direction of the injection space in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbines, and obtain the time-varying function of the gas load mass flow rate of the gas turbine by combining the energy conversion relationship of the gas turbine; discretize the time-varying function of the gas load mass flow rate of the gas turbine through the space-time orthogonal collocation method by successively combining multiple sub-periods to obtain the growth direction of the gas load mass flow rate of the gas turbine corresponding to the search direction of the injection space in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbines;

[0100] The search direction of the injection space in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbines described in Step 2 is specifically:

[0101]

[0102] where is the active power adjustment strategy of the i = 1, 2 gas turbines in the s-th sub-period;​​

[0103] The energy conversion relationship of the gas turbine unit described in step 2 is the energy conversion relationship between the active power of the gas turbine unit and the mass flow rate of the gas load at the inlet of the gas turbine unit, specifically:

[0104]

[0105] where f La,i,s is the mass flow rate of the gas load consumed by the i-th gas turbine unit in the s-th sub-period; t is the time variable; t s is the execution time of the peak shaving dispatch of the gas turbine unit; is the active power adjustment strategy of the i-th gas turbine unit in the s-th sub-period; is the rated power of the first gas turbine unit, is the rated power of the second gas turbine unit; is the maximum ramp rate of the first gas turbine unit, is the maximum ramp rate of the second gas turbine unit,; η 0i = 0 is the constant term energy consumption coefficient of the i-th gas turbine unit; η 1i = 5.9039 is the first-order term energy consumption coefficient of the i-th gas turbine unit.

[0106] The time function of the gas load mass flow rate of the gas turbine unit described in step 2, the specific calculation formula is:

[0107]

[0108] where t is the time variable; f La,i is the mass flow rate of natural gas consumed by the i-th gas turbine unit; is the mass flow rate of natural gas consumed by the i-th gas turbine unit at the initial moment of the time domain dynamic observation window; df La,i,s is the change in the mass flow rate of the gas load caused by the adjustment strategy of the i-th gas turbine unit in the s-th sub-period;

[0109] The time-varying function of the gas load mass flow rate of the gas turbine unit is discretized by the space-time orthogonal collocation method in combination with multiple sub-periods described in step 2, specifically:

[0110]

[0111] where df La,i,s is the change in the mass flow rate of the gas load caused by the adjustment strategy of the i-th gas turbine unit in the s-th sub-period; l j (τ) is the basis function of the j-th order Lagrange univariate interpolation polynomial; N t = 6 is the number of time collocation points in the space-time orthogonal collocation method; τ is the dimensionless time coordinate; is the component of the growth direction of the gas load mass flow rate of the gas turbine unit at the time configuration point j in the s-th sub-period after discretization;

[0112] The growth direction of the gas load mass flow rate of the gas turbine unit corresponding to the search direction of the injection space of the dynamic safety domain of the natural gas pipeline network for peak shaving of the gas turbine unit obtained in step 2 is specifically:

[0113]

[0114] Step 3: Take the gas source mass flow rate, pipeline inlet mass flow rate, pipeline outlet mass flow rate, pipeline mass flow rate, pipeline pressure along the line, booster station inlet pressure, booster station outlet pressure, booster station inlet mass flow rate, booster station outlet mass flow rate, and booster station gas consumption as decision variables. Discretize the decision variables through the space-time orthogonal collocation method for each sub-period in turn to obtain the decision variables for each sub-period. Maximize the safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit corresponding to the search direction of the injection space of the dynamic safety domain of the natural gas pipeline network for peak shaving of the gas turbine unit obtained in step 2 to construct an optimization objective. Combine the decision variables for each sub-period to construct constraint conditions, and optimize and solve through the simplex method optimization algorithm to obtain the optimized decision variables for each sub-period and the safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit;

[0115] The construction of the optimization objective described in step 3 is specifically defined as follows:

[0116] maxφ Fl

[0117] where φ Fl is the safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit, and max represents maximization;

[0118] The construction of the constraint conditions by combining the decision variables for each sub-period described in step 3 is specifically as follows:

[0119] The constraint conditions are composed of the total gas load mass flow rate constraint, the gas load mass flow rate constraint of the gas turbine unit, the node flow balance equation constraint, the discrete partial differential equation constraint of the dynamic pipeline flow of the natural gas pipeline network, the compressor operation constraint, the initial boundary conditions of the dynamic pipeline flow model, the dynamic pipeline flow safety constraint, and the association condition constraint between the nodes and pipeline decision variables of the natural gas pipeline network;

[0120] The total gas load mass flow rate constraint is specifically:

[0121]

[0122] where is the component of the total gas load mass flow rate at node m at the time configuration point j in the s-th sub-period; is the component of the gas load mass flow rate of the gas turbine unit at node m at the time configuration point j in the s-th sub-period; is the predicted value of the component of the conventional gas load mass flow rate at node m at the time configuration point j in the s-th sub-period; γ is the set of nodes in the natural gas system; N t = 6 is the number of time configuration points in the spatio-temporal orthogonal collocation method; N = 2 is the number of segments of the time-domain dynamic observation window of the state variable;

[0123] The constraint on the gas load mass flow rate of the gas turbine unit is specifically:

[0124]

[0125] Among them, is the component of the gas load mass flow rate of the gas turbine unit at node m at the time configuration point j in the s-th sub-period; is the mass flow rate of the gas source at node m at the initial moment t of the s-th sub-period s-1 of the gas load mass flow rate of the gas turbine unit; φ Fl is the safety margin in the growth direction of the given gas load mass flow rate of the gas turbine unit; is the component of the growth direction of the given gas load mass flow rate of the gas turbine unit at node m at the time configuration point j in the s-th sub-period; γ is the set of nodes in the natural gas system; N t = 6 is the number of time configuration points in the spatio-temporal orthogonal collocation method; N = 2 is the number of segments of the time-domain dynamic observation window of the state variable;

[0126] The constraint on the node flow balance equation is specifically:

[0127]

[0128] Among them, is the component of the mass flow rate of the gas source at node m at the time configuration point j in the s-th sub-period; is the component of the total gas load mass flow rate at node m at the time configuration point j in the s-th sub-period; is the value of the mass flow rate at the inlet node m of pipeline mn at the time configuration point j in the s-th sub-period; is the value of the mass flow rate at the outlet node n of pipeline nm at the time configuration point j in the s-th sub-period; γ is the set of nodes in the natural gas system; N t = 6 is the number of time configuration points in the spatio-temporal orthogonal collocation method; N = 2 is the number of segments of the time-domain dynamic observation window of the state variable;

[0129] The constraint on the discrete partial differential equation of dynamic pipe flow in the natural gas pipeline network is specifically:

[0130]

[0131]

[0132] wherein, is the component of the mass flow rate of pipeline mn at the spatio-temporal configuration point (i, j) in the s-th sub-period; is the component of the pressure of pipeline mn at the spatio-temporal configuration point (i, j) in the s-th sub-period; is the (i, z)-th element of the spatial first-order differential matrix ; is the (j, z)-th element of the time first-order differential matrix ; A mn is the cross-sectional area of pipeline mn; D mn is the pipeline diameter of pipeline mn; L mn is the length of pipeline mn; v s is the gas sound speed of natural gas; Δt is the time length of the s-th sub-period; Δx mn is the length of pipeline mn; λ is the wall friction coefficient; is the average gas flow velocity of pipeline mn; X is the set of pipelines in the natural gas system; N t = 6 is the number of time configuration points in the spatio-temporal orthogonal collocation method; N x = 12 is the number of spatial configuration points in the spatio-temporal orthogonal collocation method; N = 2 is the number of segments of the time-domain dynamic observation window of the state variable;

[0133] The compressor operation constraints are specifically:

[0134]

[0135]

[0136]

[0137] wherein, is the component of the outlet node pressure of booster station mn at the time configuration point j in the s-th sub-period; is the component of the inlet node pressure of booster station mn at the time configuration point j in the s-th sub-period; K Cmn is the pressure ratio of booster station m'n'; is the component of the gas consumption of booster station mn at the time configuration point j in the s-th sub-period; β mn is the gas consumption coefficient of booster station mn; is the component of the mass flow rate at the outlet node of booster station mn at the time configuration point j in the s-th sub-period; are respectively the components of the mass flow rate at the inlet node of booster station mn at the time configuration point j in the sub-period; X CThe set of pipelines where the pressurization station of the natural gas system is located; N t = 6 is the number of time collocation points in the spatio-temporal orthogonal collocation method; N = 2 is the number of segments of the time-domain dynamic observation window of the state variable;

[0138] The initial boundary conditions of the dynamic pipe flow model are specifically:

[0139]

[0140]

[0141] Among them, is the initial mass flow rate at the spatial collocation point i at the initial moment t of the s-th sub-period of pipeline mn; s-1 The initial value of the mass flow rate at the spatial collocation point i; is the initial pressure at the spatial collocation point i at the initial moment t of the s-th sub-period of pipeline mn; s-1 The initial value of the pressure at the spatial collocation point i; is the component of the mass flow rate of pipeline mn at the spatio-temporal collocation point (i, 0) of the s-th sub-period; is the component of the pressure of pipeline mn at the spatio-temporal collocation point (i, 0) of the s-th sub-period; X is the set of pipelines in the natural gas system; N x = 12 is the number of spatial collocation points in the spatio-temporal orthogonal collocation method; N = 2 is the number of segments of the time-domain dynamic observation window of the state variable;

[0142] The dynamic pipe flow safety constraints are specifically:

[0143]

[0144]

[0145]

[0146] Among them, is the component of the pressure at node m at the time collocation point j of the s-th sub-period; is the component of the mass flow rate of pipeline mn at the spatio-temporal collocation point (i, j) of the s-th sub-period; is the component of the pressure of pipeline mn at the spatio-temporal collocation point (i, j) of the s-th sub-period; p m is the lower safety limit of the pressure at node m; is the upper safety limit of the pressure at node m; p mn is the lower safety limit of the pressure of pipeline mn; is the upper safety limit of the pressure of pipeline mn; f mn is the lower safety limit of the mass flow rate of pipeline mn; is the safety upper limit of the mass flow rate of pipeline mn; γ is the set of nodes in the natural gas system; X is the set of pipelines in the natural gas system; N t = 6 is the number of time collocation points in the space-time orthogonal collocation method; N x = 12 is the number of space collocation points in the space-time orthogonal collocation method; N = 2 is the number of segments of the state variable time-domain dynamic observation window; The association condition constraint between the natural gas pipeline network nodes and the pipeline decision variables is specifically:

[0147]

[0148]

[0149]

[0150]

[0151] Among them, is the component of the mass flow rate of pipeline mn at the space-time collocation point (0, j) in the s-th sub-time period; is the value of the mass flow rate at the inlet node m of pipeline mn at the time collocation point j in the s-th sub-time period; is the component of the mass flow rate of pipeline mn at the space-time collocation point (N x , j); is the value of the mass flow rate at the inlet node m of pipeline mn at the time collocation point j in the s-th sub-time period; is the value of the mass flow rate at the outlet node n of pipeline mn at the time collocation point j in the s-th sub-time period; is the component of the pressure of pipeline mn at the space-time collocation point (0, j) in the s-th sub-time period; is the component of the pressure of pipeline mn at the space-time collocation point (N x , j); is the component of the pressure at node m at the time collocation point j in the s-th sub-time period; N t = 6 is the number of time collocation points in the space-time orthogonal collocation method; N = 2 is the number of segments of the state variable time-domain dynamic observation window;

[0152] The safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit described in step 3 is the objective function value φ obtained by the optimization solution Fl ;

[0153] Step 4: Obtain the maximum safety margin in the growth direction of the peak shaving strategy of the gas turbine unit based on the safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit and the energy conversion relationship of the gas turbine unit; furthermore, obtain the critical point of the dynamic safety domain of the natural gas pipeline network for the peak shaving of the gas turbine unit according to the growth direction of the peak shaving strategy of the gas turbine unit and the maximum safety margin in the growth direction of the peak shaving strategy of the gas turbine unit.

[0154] The maximum safety margin in the growth direction of the peak shaving strategy of the gas turbine unit described in Step 4 is specifically:

[0155] φ GPR = φ Fl

[0156] where φ GPR is the maximum safety margin in the growth direction of the peak shaving strategy of the gas turbine unit, and is equal to the safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit when the energy conversion relationship of the gas turbine unit is a linear relationship.

[0157] The critical point of the dynamic safety domain of the natural gas pipeline network for the peak shaving of the gas turbine unit described in Step 4 is specifically as follows:

[0158]

[0159] where P SRB is a critical point of the dynamic safety domain of the natural gas pipeline network for the peak shaving of the gas turbine unit, φ GPR is the maximum safety margin in the growth direction of the peak shaving strategy of the gas turbine unit, is the active power adjustment strategy of the i-th gas turbine unit in the s-th sub-period.

[0160] Step 5: Traverse each direction of the injection space of the dynamic safety domain of the natural gas pipeline network for the peak shaving of the gas turbine unit, and sequentially execute Step 2 - Step 4 to obtain the critical points of each direction of the injection space of the dynamic safety domain of the natural gas pipeline network for the peak shaving of the gas turbine unit.

[0161] Step 6: Combine the critical points of each direction of the injection space of the dynamic safety domain of the natural gas pipeline network for the peak shaving of the gas turbine unit, and further construct the boundary of the dynamic safety domain of the natural gas pipeline network for the peak shaving of the gas turbine unit through the piecewise linear fitting method, and take the area within the boundary of the dynamic safety domain of the natural gas pipeline network for the peak shaving of the gas turbine unit as the safety domain for realizing the dynamic safety assessment of the natural gas pipeline network and assisting in supporting the dispatching decision-making and optimal control of the power grid.

[0162] It should be understood that the parts not elaborated in this specification all belong to the prior art.

[0163] It should be understood that the above description of the preferred embodiment is relatively detailed, and it should not be considered as a limitation to the protection scope of the present invention. Under the inspiration of the present invention, those of ordinary skill in the art can also make substitutions or modifications without departing from the protection scope defined by the claims of the present invention, and all of them fall within the protection scope of the present invention. The scope of protection claimed by the present invention shall be subject to the appended claims.

Claims

1. A method for constructing a dynamic safety region of a natural gas pipeline network for peak shaving of gas turbine units, characterized in that, It includes the following steps: Step 1: Set the time-domain dynamic observation window of the decision variables in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbine units, and divide the time-domain dynamic observation window of the decision variables into multiple sub-periods; Step 2: Set the search direction of the injection space in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbine units, and obtain the time-varying function of the gas load mass flow rate of the gas turbine unit in combination with the energy conversion relationship of the gas turbine unit; Discretize the time-varying function of the gas load mass flow rate of the gas turbine unit through the space-time orthogonal collocation method in combination with multiple sub-periods in turn to obtain the growth direction of the gas load mass flow rate of the gas turbine unit corresponding to the search direction of the injection space in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbine units; Step 3: Construct decision variables, discretize the decision variables through the space-time orthogonal collocation method in combination with multiple sub-periods in turn to obtain the decision variables of each sub-period, construct an optimization objective with the maximum safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit corresponding to the search direction of the injection space in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbine units, construct constraint conditions in combination with the decision variables of each sub-period, and optimize and solve through the simplex method optimization algorithm to obtain the decision variables of each sub-period after optimization and the safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit; Step 4: Obtain the maximum safety margin in the growth direction of the peak shaving strategy of the gas turbine unit according to the safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit and the energy conversion relationship of the gas turbine unit; Furthermore, obtain the critical point of the dynamic safety domain of the natural gas pipeline network for peak shaving of the gas turbine unit according to the growth direction of the peak shaving strategy of the gas turbine unit and the maximum safety margin in the growth direction of the peak shaving strategy of the gas turbine unit; Step 5: Traverse each direction of the injection space in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbine units, and execute Steps 2 - 4 in turn to obtain the critical points of each direction of the injection space in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbine units; Step 6: Combine the critical points of each direction of the injection space in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbine units, and further construct the boundary of the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbine units through the piecewise linear fitting method, and take the area within the boundary of the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbine units as the safety domain for realizing the dynamic safety assessment of the natural gas pipeline network and assisting in supporting the dispatching decision-making and optimal control of the power grid.

2. The method for constructing a dynamic safety domain of a natural gas pipeline network for peak shaving of a gas turbine unit according to claim 1, characterized in that: The time-domain dynamic observation window of the decision variables in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbine units described in Step 1 is defined as: [t0, t N ​ Among them, t0 represents the initial moment of the time-domain dynamic observation window, and t N represents the termination moment of the time-domain dynamic observation window; The specific method for dividing the time-domain dynamic observation window of the decision variables into multiple sub-periods described in Step 1 is: Select multiple time-domain segmentation points in the time-domain dynamic observation window of decision variables in the dynamic safety domain of the natural gas pipeline network for the peak shaving of gas turbines according to the real-time scheduling interval of the power grid, which are specifically defined as: t0, t1, …, t s , …, t N ; where t s represents the s-th time-domain segmentation point, and N + 1 represents the number of time-domain segmentation points; The multiple sub-periods are defined as: [t0, t1], [t1, t2], …, [t s-1 , t s , …, [t N-1 , t N ​ Among them, [t s-1 , t s represents the s-th sub-period.

3. The method for constructing a dynamic safety region of a natural gas pipeline network for peak shaving of a gas turbine unit according to claim 1, wherein: The specific search direction of the injection space in the dynamic safety domain of the natural gas pipeline network for peak shaving of gas turbine units described in Step 2 is: Among them, is the active power adjustment strategy of the i-th gas turbine unit in the s-th sub-period; The energy conversion relationship of the gas turbine unit described in Step 2 is the energy conversion relationship between the active power of the gas turbine unit and the gas load mass flow rate at the gas inlet of the gas turbine unit, and specifically is: Among them, f La,i,s is the mass flow rate of gas load consumed by the i-th gas turbine during the s-th sub-period; t is the time variable; t s is the execution time of the peak shaving dispatch of the gas turbine; is the active power adjustment strategy of the i-th gas turbine during the s-th sub-period; is the rated power of the i-th gas turbine; is the maximum ramp rate of the i-th gas turbine; η 0i is the constant term energy consumption coefficient of the i-th gas turbine; η 1i is the first-order term energy consumption coefficient of the i-th gas turbine; The specific calculation formula of the time-varying function of the gas load mass flow rate of the gas turbine unit described in Step 2 is: where t is the time variable; f La,i is the mass flow rate of natural gas consumed by the i-th gas turbine unit; is the mass flow rate of natural gas consumed by the i-th gas turbine unit at the initial moment of the time-domain dynamic observation window; df La,i,s is the change in the mass flow rate of gas load caused by the adjustment strategy of the i-th gas turbine unit in the s-th sub-period; In Step 2, the time-varying function of the gas load mass flow rate of the gas turbine unit is discretized by the spatio-temporal orthogonal configuration method for combining multiple sub-periods, specifically as follows: where, df La,i,s is the change in the gas load mass flow rate caused by the adjustment strategy of the i-th gas turbine unit in the s-th sub-period; l j (τ) is the basis function of the j-th order Lagrange univariate interpolation polynomial; N t is the number of time collocation points in the space-time orthogonal collocation method; τ is the dimensionless time coordinate; is the component of the growth direction of the gas load mass flow rate of the gas turbine unit after discretization at the time collocation point j in the s-th sub-period; In Step 2, the growth direction of the gas load mass flow rate of the gas turbine unit corresponding to the search direction of the injection space of the dynamic safety domain of the natural gas pipeline network for peak shaving of the gas turbine unit is obtained, specifically as follows:

4. The method for constructing a dynamic safety domain of a natural gas pipeline network for peak shaving of a gas turbine unit according to Claim 1, wherein: The decision variables in Step 3 include: gas source mass flow rate, pipeline inlet mass flow rate, pipeline outlet mass flow rate, pipeline mass flow rate, pipeline pressure along the line, booster station inlet pressure, booster station outlet pressure, booster station inlet mass flow rate, booster station outlet mass flow rate, and booster station gas consumption; In Step 3, the optimization objective is constructed as specifically defined below: maxφ Fl where φ Fl is the safety margin in the growth direction of the gas load mass flow rate of the gas turbine unit, and max represents maximization; In Step 3, the constraint conditions are constructed by combining the decision variables of each sub-period, specifically as follows: The constraint conditions are composed of the total gas load mass flow rate constraint, the gas load mass flow rate constraint of the gas turbine unit, the node flow balance equation constraint, the discrete partial differential equation constraint of the dynamic pipeline flow of the natural gas pipeline network, the compressor operation constraint, the initial boundary conditions of the dynamic pipeline flow model, the dynamic pipeline flow safety constraint, and the association condition constraint between the decision variables of the nodes and pipelines of the natural gas pipeline network.

5. The method for constructing a dynamic safety domain of a natural gas pipeline network for peak shaving of a gas turbine unit according to Claim 4, wherein: The total gas load mass flow rate constraint is specifically as follows: Among them, is the component of the total gas load mass flow rate at node m at the time configuration point j in the s-th sub-period; is the component of the gas load mass flow rate of the gas turbine unit at node m at the time configuration point j in the s-th sub-period; is the predicted value of the component of the conventional gas load mass flow rate at node m at the time configuration point j in the s-th sub-period; Υ is the set of nodes in the natural gas system; N t is the number of time configuration points in the space-time orthogonal collocation method; N is the number of segments of the time-domain dynamic observation window of the state variable.

6. The method for constructing a dynamic safety domain of a natural gas pipeline network for peak shaving of a gas turbine unit according to Claim 4, wherein: The gas load mass flow rate constraint of the gas turbine unit is specifically as follows: Among them, is the component of the gas load mass flow rate of the gas turbine unit at node m at the time configuration point j in the s-th sub-period; is the mass flow rate of the gas source at node m at the initial moment t of the s-th sub-period s-1 of the gas load mass flow rate of the gas turbine unit; φ Fl is the safety margin in the growth direction of the given gas load mass flow rate of the gas turbine unit; is the component of the growth direction of the discretized gas load mass flow rate of the gas turbine unit at the time configuration point j in the s-th sub-period; Υ is the set of nodes in the natural gas system; N t is the number of time configuration points in the space-time orthogonal collocation method; N is the number of segments of the time-domain dynamic observation window of the state variable.

7. The method for constructing a dynamic safety domain of a natural gas pipeline network for peak shaving of a gas turbine unit according to Claim 4, wherein: The node flow balance equation constraint is specifically as follows: wherein, is the component of the mass flow rate of the gas source at node m at the time configuration point j in the s-th sub-period; is the component of the total gas load mass flow rate at node m at the time configuration point j in the s-th sub-period; is the value of the mass flow rate at the inlet node m of the pipeline mn at the time configuration point j in the s-th sub-period; is the value of the mass flow rate at the outlet node n of the pipeline nm at the time configuration point j in the s-th sub-period; Υ is the set of nodes in the natural gas system; N t is the number of time configuration points in the spatio-temporal orthogonal collocation method; N is the number of segments of the time domain dynamic observation window of the state variable.

8. The method for constructing a dynamic safety domain of a natural gas pipeline network for peak shaving of a gas turbine unit according to Claim 4, wherein: The discrete partial differential equation constraint of the dynamic pipeline flow of the natural gas pipeline network is specifically as follows: wherein, is the component of the mass flow rate of pipeline mn at the spatio-temporal configuration point (i, j) in the s-th sub-period; is the component of the pressure of pipeline mn at the spatio-temporal configuration point (i, j) in the s-th sub-period; is the (i, z)-th element of the spatial first-order differential matrix ; is the (j, z)-th element of the temporal first-order differential matrix ; A mn is the cross-sectional area of pipeline mn; D mn is the pipeline diameter of pipeline mn; L mn is the length of pipeline mn; v s is the gas flow velocity of natural gas; Δt is the time length of the s-th sub-period; Δx mn is the length of pipeline mn; λ is the wall friction coefficient; is the average gas flow velocity of pipeline mn; X is the set of pipelines in the natural gas system; N t is the number of time configuration points in the spatio-temporal orthogonal collocation method; N x is the number of spatial configuration points in the spatio-temporal orthogonal collocation method; N is the number of segments of the time-domain dynamic observation window of the state variable.

9. The method for constructing a dynamic safety domain of a natural gas pipeline network for peak shaving of a gas turbine unit according to Claim 4, wherein: The compressor operation constraint is specifically as follows: Among them, is the component of the outlet node pressure of the booster station mn at the time configuration point j in the s-th sub-period; is the component of the inlet node pressure of the booster station mn at the time configuration point j in the s-th sub-period; K Cmn is the pressure boost ratio of the booster station mn; is the component of the gas consumption of the booster station mn at the time configuration point j in the s-th sub-period; β mn is the gas consumption coefficient of the booster station mn; is the component of the mass flow rate at the outlet node of the booster station mn at the time configuration point j in the s-th sub-period; is the component of the mass flow rate at the inlet node of the booster station mn at the time configuration point j in the sub-period; X C is the set of pipelines where the booster stations in the natural gas system are located; N t is the number of time configuration points in the space-time orthogonal collocation method; N is the number of segments of the time-domain dynamic observation window of the state variable. The initial boundary conditions of the dynamic pipeline flow model are specifically as follows: Among them, is the initial moment \(t\) of pipeline \(mn\) in the \(s\)-th sub-period s-1 The initial value of the mass flow rate at the spatial configuration point \(i\); is the initial moment \(t\) of pipeline \(mn\) in the \(s\)-th sub-period s-1 The initial value of the pressure at the spatial configuration point \(i\); is the component of the mass flow rate of pipeline \(mn\) at the spatio-temporal configuration point \((i, 0)\) in the \(s\)-th sub-period; is the component of the pressure of pipeline \(mn\) at the spatio-temporal configuration point \((i, 0)\) in the \(s\)-th sub-period; \(X\) is the set of pipelines in the natural gas system; \(N\) x is the number of spatial configuration points in the spatio-temporal orthogonal collocation method; \(N\) is the number of segments of the time-domain dynamic observation window of the state variable; The dynamic pipeline flow safety constraint is specifically as follows: wherein, is the component of the pressure at node m at the time collocation point j in the s-th sub-time period; is the component of the mass flow rate of pipeline mn at the spatio-temporal collocation point (i, j) in the s-th sub-time period; is the component of the pressure of pipeline mn at the spatio-temporal collocation point (i, j) in the s-th sub-time period; p m is the lower safety limit of the pressure at node m; is the upper safety limit of the pressure at node m; p mn is the lower safety limit of the pressure of pipeline mn; is the upper safety limit of the pressure of pipeline mn; f mn is the lower safety limit of the mass flow rate of pipeline mn; is the upper safety limit of the mass flow rate of pipeline mn; Υ is the set of nodes in the natural gas system; X is the set of pipelines in the natural gas system; N t is the number of time collocation points in the spatio-temporal orthogonal collocation method; N x is the number of space collocation points in the spatio-temporal orthogonal collocation method; N is the number of segments of the time domain dynamic observation window of the state variable; The association condition constraints between the natural gas pipeline network nodes and the pipeline decision variables are specifically as follows: wherein, is the component of the mass flow rate of pipeline mn at the spatio-temporal configuration point (0, j) in the s-th sub-period; is the value of the mass flow rate at the inlet node m of pipeline mn at the time configuration point j in the s-th sub-period; is the mass flow rate of pipeline mn at the spatio-temporal configuration point (N x , j) in the s-th sub-period; is the value of the mass flow rate at the inlet node m of pipeline mn at the time configuration point j in the s-th sub-period; is the value of the mass flow rate at the outlet node n of pipeline mn at the time configuration point j in the s-th sub-period; is the component of the pressure of pipeline mn at the spatio-temporal configuration point (0, j) in the s-th sub-period; is the component of the pressure of pipeline mn at the spatio-temporal configuration point (N x , j) in the s-th sub-period; is the component of the pressure at node m at the time configuration point j in the s-th sub-period; N t is the number of time configuration points in the spatio-temporal orthogonal collocation method; N is the number of segments of the time-domain dynamic observation window of the state variable. The safety margin in the growth direction of the gas load mass flow rate described in Step 3 is the objective function value φ obtained by the optimization solution Fl .

10. The method for constructing a dynamic safety domain of a natural gas pipeline network for peak shaving of a gas turbine unit according to claim 1, wherein: In Step 4, the maximum safety margin in the growth direction of the peak shaving strategy of the gas turbine unit is specifically as follows: φ GPR = φ Fl where φ GPR is the maximum safety margin in the growth direction of the peak shaving strategy of the gas turbine unit, and is equal to the safety margin in the growth direction of the gas mass flow rate of the gas turbine unit when the energy conversion relationship of the gas turbine unit is linear; The critical points of the dynamic safety domain of the natural gas pipeline network for peak shaving of the gas turbine unit in Step 4 are specifically as follows: Among them, P SRB is a critical point of the dynamic safety region of the natural gas pipeline network for the peak shaving of gas turbine units, and φ GPR is the maximum safety margin in the growth direction of the peak shaving strategy of gas turbine units. is the active power adjustment strategy of the i-th gas turbine unit in the s-th sub-period.

Images