High-altitude region power grid energy storage optimization planning method for maximizing power supply reliability

Abstract

The invention discloses a high-altitude region power grid energy storage optimization planning method capable of maximizing power supply reliability. The method comprises the following steps: S1, obtaining a high-altitude region supply guarantee / absorption promotion index; s2, establishing a double-layer model based on the power grid demand and supply guarantee / absorption promotion indexes in the high-altitude region, the double-layer model comprising an upper-layer model and a lower-layer model which are connected with each other; and S3, calculating an energy storage layout position and capacity power configuration through the upper layer model, inputting the energy storage layout position and capacity power configuration into the lower layer model, calculating output power of power generation side equipment and energy storage equipment through the lower layer model, inputting the output power into the upper layer model, and ensuring high-altitude region power grid energy storage optimal configuration considering load supply guarantee and clean energy consumption. According to the method, double-layer model construction of energy storage optimal configuration and operation considering supply guarantee and absorption promotion is realized, and the feasibility and effectiveness of the proposed strategy are verified through an actual power system in a certain high-altitude area.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage planning, and in particular relates to a method for optimizing energy storage planning for power grids in high-altitude areas to maximize power supply reliability. Background Art

[0002] The increasing penetration of clean energy in new power systems, coupled with the randomness, intermittency, and volatility inherent in clean energy, poses increasingly challenging challenges to grid supply and absorption. When clean energy is generating at full capacity, insufficient system absorption capacity can lead to wind and solar curtailment, hindering the achievement of carbon emission reduction targets. Furthermore, when clean energy is not generating or generating very little, insufficient power on the system's power supply side can easily lead to load shortages and power rationing, severely impacting local industrial production and residents' daily lives. In new power systems, deploying electrochemical energy storage is an effective way to smooth out fluctuations in renewable energy generation and alleviate supply and demand imbalances. Electrochemical energy storage systems balance grid supply and demand by absorbing and releasing peak power from the source, addressing power regulation needs across multiple scenarios and timescales. However, in large regional power grids, clean energy-rich areas are often located far from load clusters. The grid losses caused by long-distance transmission not only limit the flow and absorption of clean energy, but also create the potential risk of power curtailment and outages. One of the key approaches to accelerating the transformation of new power systems is to ensure optimal energy storage system costs while balancing supply and consumption goals to achieve system power stability and balance. Existing technologies independently set power outage rates, curtailment rates, and reliability indicators to ensure load supply while increasing consumption rates and reducing carbon emissions. However, these technologies fail to simultaneously integrate supply and consumption goals with the actual needs of the regional power grid to characterize and analyze indicators and achieve optimal energy storage configuration that balances these goals. Summary of the Invention

[0003] In response to the above-mentioned deficiencies in the existing technology, the present invention provides a method for optimizing energy storage planning for power grids in high-altitude areas to maximize power supply reliability, which solves the problem that the existing technology cannot simultaneously combine the goals of ensuring supply and promoting consumption with the actual needs of the regional power grid to implement energy storage optimization configuration.

[0004] To achieve the above-mentioned purpose, the present invention adopts a technical solution: a method for optimizing energy storage planning for power grids in high-altitude areas to maximize power supply reliability, comprising the following steps:

[0005] S1. Obtain supply guarantee / consumption promotion indicators in high-altitude areas;

[0006] S2. Based on the grid demand and supply guarantee / consumption promotion indicators in high-altitude areas, a two-layer model is established, including an upper-layer model and a lower-layer model that are interconnected;

[0007] S3. Calculate the layout location and capacity power configuration of energy storage through the upper-level model and input it into the lower-level model. Calculate the output power of the power generation equipment and energy storage equipment through the lower-level model and input it into the upper-level model to ensure the optimal configuration of energy storage in high-altitude power grids that takes into account both load supply and clean energy consumption.

[0008] Furthermore: in said S1, the supply guarantee / consumption promotion indicators in high altitude areas include consumption promotion indicators, power restriction indicators and power shortage indicators.

[0009] Furthermore: The specific expression of the consumption promotion index is:

[0010]

[0011] Where η PC To promote consumption indicators, P Curtailment (t) is the abandoned power of clean energy at time t, P Generation (t) is the power generated by clean energy at time t, T is the system operation cycle, and N is the number of clean energy power generation equipment;

[0012] The specific expression of power restriction index is:

[0013] η LE =P Load_supply (t) / P Load (t)

[0014] Where η LE is the power restriction index, P Load_supply (t) is the power supply to the load at time t, P Load (t) is the power demanded by the load during the dispatch period;

[0015] The specific expression of power shortage index is:

[0016]

[0017] Where η PS is the power restriction index, P Load_shortage (t) is the power shortage of the load at time t.

[0018] The beneficial effect of the above further scheme is: the present invention uses three variables, namely, consumption promotion index, power restriction index and power shortage index, to characterize the supply guarantee and consumption promotion index, so that the power system can achieve the best balance between ensuring reliable power supply and promoting the consumption of new energy.

[0019] Furthermore: in said S2, the decision variables for the upper-level model to calculate the layout location and capacity and power configuration of the energy storage are the configuration nodes, configuration capacity and maximum input / output power of the energy storage system;

[0020] The objective function of the upper model is the comprehensive cost C of the system, and its specific expression is:

[0021] minC=C1+C2

[0022] Where C1 is the total cost of the energy storage system, and C2 is the system power generation / purchase cost.

[0023] Furthermore, the total cost of the energy storage system is expressed as follows:

[0024]

[0025] Where C inv is the investment cost, C O&M is the charge and discharge cost, R ESS is the conversion coefficient of the energy storage system, is the unit capacity investment cost of the energy storage system, is the grid-connected capacity of the energy storage system at node l, N ESS is the total number of nodes where energy storage systems are installed, is the unit power charging and discharging cost of the energy storage system, is the charging and discharging power of the energy storage system at node l, is the service life of the energy storage system, r ESS is the discount rate for the energy storage system;

[0026] The expression of system power generation / purchase cost is as follows:

[0027]

[0028] Where, is the cost of thermal power generation, is the cost of hydropower generation, is the tie line switching cost, N TP is the total number of thermal power generating units, is the unit power generation cost of the thermal power generating unit, is the power generation capacity of the thermal power generator at node i, N Hyrdo is the total number of hydroelectric generating units, is the unit power generation cost of the hydroelectric generator set, is the power generation capacity of the hydroelectric generator set at node k, is the unit exchange cost of the net exchange power of the tie line between the regional power system and the external power system, It is the net exchange power of the tie line between the regional power system and the external power system.

[0029] Furthermore: in S2, the constraints of the upper model are the safety and stability constraints of the system, including power generation side constraints, grid side constraints, energy storage side constraints and system power balance constraints.

[0030] Furthermore, the generation side constraints include the output constraints of thermal power stations, photovoltaic power stations, and hydropower stations. The specific expression of the generation side constraints is:

[0031]

[0032] Where, is the power generation power of the photovoltaic generator set at node j, is the minimum output power of the thermal power unit at node i, is the maximum output power of the thermal power unit at node i, is the maximum output power of photovoltaic power generation at node j, is the maximum output power of the hydropower station at node k;

[0033] The specific expression of the grid side constraint is:

[0034]

[0035] Where, P ab is the line transmission power between node a and node b, θ a is the phase angle of node a, θ b is the phase angle of node b, X ab is the reactance of the line between node a and node b, P max,ab is the maximum transmission power of the line between node a and node b, P Line is the transmission power of the tie line, P max,Line is the maximum transmission power of the tie line;

[0036] The specific expression of the energy storage side constraint is:

[0037]

[0038] Where, is the rated power of the energy storage system at node l, is a 0-1 variable, indicating whether an energy storage system is installed at node l. is the upper limit of the power allowed for the energy storage system installed at node l, is the capacity change of the energy storage system at node l during the Δt period, is the rated capacity of the energy storage system at node l, is the upper limit of the capacity of the energy storage system allowed to be installed at node l;

[0039] The expression of system power balance constraint is as follows:

[0040]

[0041] Where NPV is the number of photovoltaic power stations and energy storage systems, P Load is the load power.

[0042] Furthermore: in said S2, the decision variables for the lower-level model to calculate the output power of the power generation side equipment and the energy storage equipment are the output power of the conventional synchronous generator set, the clean energy and the energy storage system;

[0043] The objective function of the lower model is the daily operating cost C of the system generation , its specific expression is:

[0044]

[0045] Where, is the power generation cost of thermal power units, The penalty cost for abandoning light, is the power generation cost of the hydropower unit, is the operating cost of the energy storage system, is the power shortage penalty cost, and its specific expression is:

[0046]

[0047] Where, is the on-grid electricity price for photovoltaic power generation, is the unit power charging and discharging cost of the energy storage system, is the unit power charging and discharging cost of the energy storage system, is the power generation of the thermal power generating unit at node i at time t, is the power generation of the photovoltaic generator set at node j at time t, is the predicted power generation of the photovoltaic generator set at node j at time t, is the power generation of the hydroelectric generator set at node k at time t, is the charging power of the energy storage system at node k at time t, is the discharge power of the energy storage system at node k at time t, The efficiency of charging the energy storage system, is the discharge efficiency of the energy storage system, is the net exchange power of the tie line at time t, is the load power shortage at time t.

[0048] Furthermore: in said S2, the constraints of the lower model include system power balance constraints, spinning reserve constraints, constraints on both supply guarantee and consumption promotion, generation side output constraints, and energy storage side constraints;

[0049] The expression of system power balance constraint is as follows:

[0050]

[0051] The specific expression of the spinning reserve constraint is:

[0052]

[0053] Where R(t) is the spinning reserve of the system at time t;

[0054] The specific expression for balancing supply guarantee and consumption promotion is:

[0055]

[0056] Where λ1 is the upper limit of the power curtailment rate of the system due to the inability of new energy to be absorbed, λ2 is the ratio coefficient of the power shortage load to the maximum load power in the t period, and λ3 is the upper limit of the power shortage rate of the load;

[0057] The specific expression of the power generation side output constraint is:

[0058]

[0059] The specific expression of the energy storage side constraint is:

[0060]

[0061] Where, is the charging power of the energy storage system at node k at time t, is the discharge power of the energy storage system at node k at time t, represents the charge and discharge state of the energy storage system at node k at time t, When it is discharged, When it is charging, is the initial state of charge of the energy storage system at node l within one day, is the final state of charge of the energy storage system at node l within one day, is the minimum state of charge of the energy storage system at node l during the scheduling process, is the maximum state of charge of the energy storage system at node l during the scheduling process.

[0062] The beneficial effects of the present invention are as follows: the present invention provides a method for optimizing energy storage planning for power grids in high-altitude areas to maximize power supply reliability. The method takes power grids in high-altitude areas as the research object, characterizes supply guarantee / consumption promotion indicators based on the power grid demand in high-altitude areas, clusters typical operation scenarios of local power grids based on historical data, and performs energy storage planning and configuration through the upper-level model based on the typical operation scenario data. The obtained configuration results are substituted into the lower-level model, and the operation layer with supply guarantee and consumption promotion constraints is considered to realize the construction of a two-layer model for energy storage optimization configuration and operation that takes into account both supply guarantee and consumption promotion. Finally, the feasibility and effectiveness of the proposed strategy are verified through the actual power system in a certain high-altitude area. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 This is a flow chart of the method for optimizing energy storage planning for power grids in high altitude areas to maximize power supply reliability according to the present invention.

[0064] Figure 2 Schematic diagram of power grid demand analysis in high-altitude areas.

[0065] Figure 3 Schematic diagram of the two-layer model.

[0066] Figure 4 This is the wiring diagram of the power grid in a high-altitude area in western China.

[0067] Figure 5 This is the typical daily photovoltaic and load curve.

[0068] Figure 6 Optimize operation results for power grids in high altitude areas. DETAILED DESCRIPTION

[0069] The specific embodiments of the present invention are described below to facilitate understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

[0070] like Figure 1 As shown, in one embodiment of the present invention, a method for optimizing energy storage planning for power grids in high altitude areas to maximize power supply reliability includes the following steps:

[0071] S1. Obtain supply guarantee / consumption promotion indicators in high-altitude areas;

[0072] S2. Based on the grid demand and supply guarantee / consumption promotion indicators in high-altitude areas, a two-layer model is established, including an upper-layer model and a lower-layer model that are interconnected;

[0073] S3. Calculate the layout location and capacity power configuration of energy storage through the upper-level model and input it into the lower-level model. Calculate the output power of the power generation equipment and energy storage equipment through the lower-level model and input it into the upper-level model to ensure the optimal configuration of energy storage in high-altitude power grids that takes into account both load supply and clean energy consumption.

[0074] In S1, the supply guarantee / consumption promotion indicators in high-altitude areas include consumption promotion indicators, power restriction indicators and power shortage indicators.

[0075] In this embodiment, the present invention uses three variables, namely, consumption promotion index, power restriction index, and power shortage index, to characterize supply guarantee and consumption promotion indexes, so that the power system can achieve the best balance between ensuring reliable power supply and promoting new energy consumption.

[0076] The consumption promotion index is defined as the ratio of clean energy curtailment to total clean energy generation. This index aims to improve the power system's ability to absorb clean energy such as wind and solar energy and reduce the phenomenon of curtailment. The specific expression of the consumption promotion index is:

[0077]

[0078] Where η PC To promote consumption indicators, P Curtailment (t) is the abandoned power of clean energy at time t, P Generation (t) is the power generated by clean energy at time t, T is the system operation cycle, and N is the number of clean energy power generation equipment;

[0079] The power restriction index is defined as the ratio of the load power supply to the maximum load power demand during the dispatch cycle. This index aims to constrain the lower limit of the power supply capacity of the power system to reduce power shortages and ensure the normal production of enterprises and the normal life of residents. The specific expression of the power restriction index is:

[0080] η LE =P Load_supply (t) / P Load (t)

[0081] Where η LE is the power restriction index, P Load_supply (t) is the power supply to the load at time t, P Load (t) is the power demanded by the load during the dispatch period;

[0082] The power shortage index is defined as the ratio of the cumulative load power shortage to the total load power during the dispatch cycle. This index aims to measure the degree of power shortage in the power system under tight supply and demand conditions. It is used to quantify and manage the power gap of the power grid and improve the power supply capacity of the load. The specific expression of the power shortage index is:

[0083]

[0084] Where η PS is the power restriction index, P Load_shortage (t) is the power shortage of the load at time t.

[0085] In S2, the demand for power grids in high altitude areas is analyzed. The population in high altitude areas is relatively sparse, and the load distribution is relatively dispersed. In addition, areas rich in new energy are usually far away from load nodes, and long-distance power transmission across mountainous areas is required between power sources and load nodes. The stability and reliability of power supply are difficult to guarantee. Due to the long transmission lines and complex terrain, the power grid faces risks such as natural disasters and extreme weather, which can easily lead to power outages. How to ensure reliable power supply in remote areas has become one of the key needs of power grids in high altitude areas. The energy storage system can store excess electricity when clean energy power generation exceeds demand, and release the stored energy when power generation is insufficient, to achieve peak shaving and valley filling, and smooth the volatility of energy supply. As Figure 2 As shown, the deployment of energy storage systems enables the grid to more flexibly dispatch clean energy, avoiding wind and solar curtailment, thereby improving clean energy utilization efficiency and grid stability. Energy storage systems can serve as emergency backup power sources. In the event of a main grid failure or power shortage, they can quickly respond and ensure reliable power supply in remote areas. In areas with limited power generation equipment and complete reliance on external power sources, energy storage systems can provide independent power supply, enhancing grid resilience and power supply assurance, ensuring continuity and reliability.

[0086] Based on the characterization of grid demand in high altitude areas and supply guarantee / consumption promotion indicators, this paper establishes a two-layer model for optimizing the configuration and operation of grid energy storage in high altitude areas, which takes into account both load supply guarantee and clean energy consumption. Figure 3 shown.

[0087] The upper-level energy storage optimization configuration model solves the energy storage system planning problem, primarily including the energy storage layout location and capacity and power configuration. The upper-level optimization decision variables are the energy storage system's configuration nodes, configuration capacity, and maximum input and output power. The objective function is the overall system cost, including the energy storage investment cost and system operating costs, such as power generation costs and network loss costs. Constraints are system safety and stability constraints, including grid power flow constraints, branch transmission power constraints, and system power balance constraints.

[0088] In S2, the upper model calculates the layout location and capacity power configuration of energy storage, and the decision variables are the configuration nodes, configuration capacity and maximum input / output power of the energy storage system;

[0089] The objective function of the upper model is the comprehensive cost C of the system, and its specific expression is:

[0090] minC=C1+C2

[0091] Where C1 is the total cost of the energy storage system, and C2 is the system power generation / purchase cost.

[0092] The total cost of the energy storage system is expressed as follows:

[0093]

[0094] Where C inv is the investment cost, C O&M is the charge and discharge cost, R ESS is the conversion coefficient of the energy storage system, is the unit capacity investment cost of the energy storage system, is the grid-connected capacity of the energy storage system at node l, N ESS is the total number of nodes where energy storage systems are installed, is the unit power charging and discharging cost of the energy storage system, is the charging and discharging power of the energy storage system at node l, is the service life of the energy storage system, r ESS is the discount rate for the energy storage system;

[0095] The expression of system power generation / purchase cost is as follows:

[0096]

[0097] Where, is the cost of thermal power generation, is the cost of hydropower generation, is the tie line switching cost, N TP is the total number of thermal power generating units, is the unit power generation cost of the thermal power generating unit, is the power generation capacity of the thermal power generator at node i, N Hyrdo is the total number of hydroelectric generating units, is the unit power generation cost of the hydroelectric generator set, is the power generation capacity of the hydroelectric generator set at node k, is the unit exchange cost of the net exchange power of the tie line between the regional power system and the external power system, It is the net exchange power of the tie line between the regional power system and the external power system.

[0098] In S2, the constraints of the upper model are the safety and stability constraints of the system, including power generation side constraints, grid side constraints, energy storage side constraints and system power balance constraints.

[0099] The generation side constraints include the output constraints of thermal power stations, photovoltaic power stations, and hydropower stations. The specific expression of the generation side constraints is:

[0100]

[0101] Where, is the power generation power of the photovoltaic generator set at node j, is the minimum output power of the thermal power unit at node i, is the maximum output power of the thermal power unit at node i, is the maximum output power of photovoltaic power generation at node j, is the maximum output power of the hydropower station at node k;

[0102] On the grid side, the branch carrying capacity, tie line carrying capacity, and DC power flow constraints are considered. The specific expression of the grid side constraints is:

[0103]

[0104] Where, P ab is the line transmission power between node a and node b, θ a is the phase angle of node a, θ b is the phase angle of node b, X ab is the reactance of the line between node a and node b, P max,ab is the maximum transmission power of the line between node a and node b, P Line is the transmission power of the tie line, P max,Line is the maximum transmission power of the tie line;

[0105] The energy storage side mainly considers the rated capacity constraint of the energy storage configuration, the rated power constraint, and the constraint relationship between the energy storage capacity change and the energy storage operating power. The specific expression of the energy storage side constraint is:

[0106]

[0107] Where, is the rated power of the energy storage system at node l, is a 0-1 variable, indicating whether an energy storage system is installed at node l. is the upper limit of the power allowed for the energy storage system installed at node l, is the capacity change of the energy storage system at node l during the Δt period, is the rated capacity of the energy storage system at node l, is the upper limit of the capacity of the energy storage system allowed to be installed at node l;

[0108] The power output of the power system must be equal to the sum of the power on the load side and the power on the energy storage side. The specific expression of the system power balance constraint is:

[0109]

[0110] Where N PV is the number of photovoltaic power stations and energy storage systems, P Load is the load power.

[0111] In S2, the lower-level model is responsible for solving the operational problems of the energy storage system, primarily by optimizing the output of power generation and energy storage equipment to achieve optimal system economics while balancing supply and consumption goals. The decision variables for the lower-level optimization are the output of conventional synchronous generators, clean energy, and the energy storage system. The objective function is the system's operating costs, including system power generation / purchase costs, energy storage operating costs, and penalty costs for curtailment, curtailment, and power shortages. The constraints primarily include the system's power balance, supply guarantee, and consumption promotion.

[0112] In S2, the decision variables for the lower model to calculate the output power of the power generation equipment and the energy storage equipment are the output power of the conventional synchronous generator set, the clean energy and the energy storage system;

[0113] In this embodiment, the lower-level optimization operation considers the lowest system operating cost, including system power generation / purchase costs, energy storage operating costs, curtailment penalty costs, power restriction penalties, and power shortage penalty costs, while taking into account economic efficiency, supply guarantee, and consumption promotion goals. The objective function of the lower-level model is the daily operating cost C of the system. generation , its specific expression is:

[0114]

[0115] Where, is the power generation cost of thermal power units, The penalty cost for abandoning light, is the power generation cost of the hydropower unit, is the operating cost of the energy storage system, Penalty costs for power outages;

[0116]

[0117] Where, is the on-grid electricity price for photovoltaic power generation, is the unit power charging and discharging cost of the energy storage system, is the unit power charging and discharging cost of the energy storage system, is the power generation of the thermal power generating unit at node i at time t, is the power generation of the photovoltaic generator set at node j at time t, is the predicted power generation of the photovoltaic generator set at node j at time t, is the power generation of the hydroelectric generator set at node k at time t, is the charging power of the energy storage system at node k at time t, is the discharge power of the energy storage system at node k at time t, The efficiency of charging the energy storage system, is the discharge efficiency of the energy storage system, is the net exchange power of the tie line at time t, is the load power shortage at time t.

[0118] In S2, the constraints of the lower model include system power balance constraints, spinning reserve constraints, constraints that balance supply and consumption, generation side output constraints, and energy storage side constraints.

[0119] The expression of system power balance constraint is as follows:

[0120]

[0121] In this embodiment, the system power balance constraint indicates that within any operation cycle, the source-side output power of the power system must be equal to the sum of the load-side power and the energy storage-side power.

[0122] The specific expression of the spinning reserve constraint is:

[0123]

[0124] Where R(t) is the spinning reserve of the system at time t;

[0125] In this embodiment, the spinning reserve constraint means that a certain amount of generating capacity must be reserved during normal operation of the power system so that it can be quickly put into use in an emergency, such as a generator failure, a sudden load increase, or a line failure, to maintain system stability.

[0126] The specific expression for balancing supply guarantee and consumption promotion is:

[0127]

[0128] Where λ1 is the upper limit of the power curtailment rate of the system due to the inability of new energy to be absorbed, λ2 is the ratio coefficient of the power shortage load to the maximum load power in the t period, and λ3 is the upper limit of the power shortage rate of the load;

[0129] The specific expression of the power generation side output constraint is:

[0130]

[0131] In this embodiment, the power generation side output constraints include output constraints of thermal power stations, photovoltaic power stations, and hydropower stations.

[0132] The specific expression of the energy storage side constraint is:

[0133]

[0134] Where, is the charging power of the energy storage system at node k at time t, is the discharge power of the energy storage system at node k at time t, represents the charge and discharge state of the energy storage system at node k at time t, When it is discharged, When it is charging, is the initial state of charge of the energy storage system at node l within one day, is the final state of charge of the energy storage system at node l within one day, is the minimum state of charge of the energy storage system at node l during the scheduling process, is the maximum state of charge of the energy storage system at node l during the scheduling process.

[0135] In this embodiment, the energy storage side constraints mainly consider the battery charging power constraint, discharge power constraint, energy storage SOC constraint and energy storage capacity change constraint within the scheduling cycle.

[0136] In S3, the upper and lower models work together to configure the energy storage system. This allows the grid to more flexibly dispatch clean energy, avoid wind and solar curtailment, and thus improve the efficiency of clean energy utilization and grid stability. The energy storage system can be configured as an emergency backup power source. In the event of a main grid failure or power shortage, the energy storage system can respond quickly to ensure reliable power supply in remote areas. In areas where power generation equipment is scarce and completely dependent on external power supply, the energy storage system can serve as an independent power supply, enhancing the grid's resilience and power supply guarantee capabilities, and ensuring the continuity and reliability of power supply.

[0137] The present invention also provides a specific experimental case:

[0138] A simulation model is established by taking a power grid in a high-altitude area in western China as an example, setting the dispatch cycle to 24 hours and the dispatch step to 1 hour. The wiring diagram of the example system is shown in the figure below. Figure 4 As shown, the system has a total of 51 nodes and 59 branches, among which thermal power stations, hydropower stations and photovoltaic power stations have been configured. The typical daily photovoltaic and load curves are shown in Figure 5 As shown in the figure, the results of the optimized operation of the power grid in high altitude areas are as follows: Figure 6 shown.

[0139] The beneficial effects of the present invention are as follows: the present invention provides a method for optimizing energy storage planning for power grids in high-altitude areas to maximize power supply reliability. The method takes power grids in high-altitude areas as the research object, characterizes supply guarantee / consumption promotion indicators based on the power grid demand in high-altitude areas, clusters typical operation scenarios of local power grids based on historical data, and performs energy storage planning and configuration through the upper-level model based on the typical operation scenario data. The obtained configuration results are substituted into the lower-level model, and the operation layer with supply guarantee and consumption promotion constraints is considered to realize the construction of a two-layer model for energy storage optimization configuration and operation that takes into account both supply guarantee and consumption promotion. Finally, the feasibility and effectiveness of the proposed strategy are verified through the actual power system in a certain high-altitude area.

[0140] In the description of the present invention, it should be understood that the orientations or positional relationships indicated by terms such as "center," "thickness," "upper," "lower," "horizontal," "top," "bottom," "inner," "outer," and "radial" are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or the number of technical features implicitly specified. Therefore, features defined by "first," "second," and "third" may explicitly or implicitly include one or more of such features.

Claims

1. A method for optimizing energy storage planning for power grids in high altitude areas to maximize power supply reliability, characterized by: The following steps are involved: S1. Obtain supply guarantee / consumption promotion indicators in high-altitude areas; S2. Based on the grid demand and supply guarantee / consumption promotion indicators in high-altitude areas, a two-layer model is established, including an upper-layer model and a lower-layer model that are interconnected; S3. Calculate the layout location and capacity power configuration of energy storage through the upper-level model and input it into the lower-level model. Calculate the output power of the power generation equipment and energy storage equipment through the lower-level model and input it into the upper-level model to ensure the optimal configuration of energy storage in high-altitude power grids that takes into account both load supply and clean energy consumption.

2. The method for optimizing energy storage planning for power grids in high altitude areas to maximize power supply reliability according to claim 1, characterized in that: In S1, the supply guarantee / consumption promotion indicators in high-altitude areas include consumption promotion indicators, power restriction indicators and power shortage indicators.

3. The method for optimizing energy storage planning for power grids in high altitude areas to maximize power supply reliability according to claim 2, characterized in that: The specific expression of the consumption promotion index is: Where η PC To promote consumption indicators, P Curtailment (t) is the abandoned power of clean energy at time t, P Generation (t) is the power generated by clean energy at time t, T is the system operation cycle, and N is the number of clean energy power generation equipment; The specific expression of power restriction index is: η LE =P Load_supply (t) / P Load (t) Where η LE is the power restriction index, P Load_supply (t) is the power supply to the load at time t, P Load (t) is the power demanded by the load during the dispatch period; The specific expression of power shortage index is: Where η PS is the power restriction index, P Load_shortage (t) is the power shortage of the load at time t.

4. The method for optimizing energy storage planning for power grids in high altitude areas to maximize power supply reliability according to claim 1, characterized in that: In S2, the upper model calculates the layout location and capacity power configuration of energy storage, and the decision variables are the configuration nodes, configuration capacity and maximum input / output power of the energy storage system; The objective function of the upper model is the comprehensive cost C of the system, and its specific expression is: minC=C1+C2 Where C1 is the total cost of the energy storage system, and C2 is the system power generation / purchase cost.

5. The method for optimizing energy storage planning for power grids in high altitude areas to maximize power supply reliability according to claim 4, characterized in that: The total cost of the energy storage system is expressed as follows: Where C inv is the investment cost, C O&M is the charge and discharge cost, R ESS is the conversion coefficient of the energy storage system, is the unit capacity investment cost of the energy storage system, is the grid-connected capacity of the energy storage system at node l, N ESS is the total number of nodes where energy storage systems are installed, is the unit power charging and discharging cost of the energy storage system, is the charging and discharging power of the energy storage system at node l, is the service life of the energy storage system, r ESS is the discount rate for the energy storage system; The expression of system power generation / purchase cost is as follows: Where, is the cost of thermal power generation, is the cost of hydropower generation, is the tie line switching cost, N TP is the total number of thermal power generating units, is the unit power generation cost of the thermal power generating unit, P i TP is the power generation capacity of the thermal power generator at node i, N Hyrdo is the total number of hydroelectric generating units, is the unit power generation cost of the hydroelectric generator set, is the power generation capacity of the hydroelectric generator set at node k, is the unit exchange cost of the net exchange power of the tie line between the regional power system and the external power system, It is the net exchange power of the tie line between the regional power system and the external power system.

6. The method for optimizing energy storage planning for power grids in high altitude areas to maximize power supply reliability according to claim 5, characterized in that: In S2, the constraints of the upper model are the safety and stability constraints of the system, including power generation side constraints, grid side constraints, energy storage side constraints and system power balance constraints.

7. The method for optimizing energy storage planning for power grids in high altitude areas to maximize power supply reliability according to claim 6, characterized in that: The generation side constraints include the output constraints of thermal power stations, photovoltaic power stations, and hydropower stations. The specific expression of the generation side constraints is: Where, is the power generation power of the photovoltaic generator set at node j, is the minimum output power of the thermal power unit at node i, is the maximum output power of the thermal power unit at node i, is the maximum output power of photovoltaic power generation at node j, is the maximum output power of the hydropower station at node k; The specific expression of the grid side constraint is: Where, P ab is the line transmission power between node a and node b, θ a is the phase angle of node a, θ b is the phase angle of node b, X ab is the reactance of the line between node a and node b, P max,ab is the maximum transmission power of the line between node a and node b, P Line is the transmission power of the tie line, P max,Line is the maximum transmission power of the tie line; The specific expression of the energy storage side constraint is: Where, is the rated power of the energy storage system at node l, is a 0-1 variable, indicating whether an energy storage system is installed at node l. is the upper limit of the power allowed for the energy storage system installed at node l, is the capacity change of the energy storage system at node l during the Δt period, is the rated capacity of the energy storage system at node l, is the upper limit of the capacity of the energy storage system allowed to be installed at node l; The expression of system power balance constraint is as follows: Where N PV is the number of photovoltaic power stations and energy storage systems, P Load is the load power.

8. The method for optimizing energy storage planning for power grids in high altitude areas to maximize power supply reliability according to claim 7, characterized in that: In S2, the decision variables for the lower model to calculate the output power of the power generation equipment and the energy storage equipment are the output power of the conventional synchronous generator set, the clean energy and the energy storage system; The objective function of the lower model is the daily operating cost C of the system generation , its specific expression is: Where, is the power generation cost of thermal power units, The penalty cost for abandoning light, is the power generation cost of the hydropower unit, is the operating cost of the energy storage system, is the power shortage penalty cost, and its specific expression is: Where, is the on-grid electricity price for photovoltaic power generation, is the unit power charging and discharging cost of the energy storage system, is the unit power charging and discharging cost of the energy storage system, P i TP (t) is the power generation of the thermal power generating unit at node i at time t, is the power generation of the photovoltaic generator set at node j at time t, is the predicted power generation of the photovoltaic generator set at node j at time t, is the power generation of the hydroelectric generator set at node k at time t, is the charging power of the energy storage system at node k at time t, is the discharge power of the energy storage system at node k at time t, The efficiency of charging the energy storage system, is the discharge efficiency of the energy storage system, is the net exchange power of the tie line at time t, is the load power shortage at time t.

9. The method for optimizing energy storage planning for power grids in high altitude areas to maximize power supply reliability according to claim 8, characterized in that: In S2, the constraints of the lower model include system power balance constraints, spinning reserve constraints, constraints on both supply and consumption, generation side output constraints, and energy storage side constraints. The expression of system power balance constraint is as follows: The specific expression of the spinning reserve constraint is: Where R(t) is the spinning reserve of the system at time t; The specific expression for balancing supply guarantee and consumption promotion is: Where λ1 is the upper limit of the power curtailment rate of the system due to the inability of new energy to be absorbed, λ2 is the ratio coefficient of the power shortage load to the maximum load power in the t period, and λ3 is the upper limit of the power shortage rate of the load; The specific expression of the power generation side output constraint is: The specific expression of the energy storage side constraint is: Where, is the charging power of the energy storage system at node k at time t, is the discharge power of the energy storage system at node k at time t, represents the charge and discharge state of the energy storage system at node k at time t, When it is discharged, When it is charging, is the initial state of charge of the energy storage system at node l within one day, is the final state of charge of the energy storage system at node l within one day, is the minimum state of charge of the energy storage system at node l during the scheduling process, is the maximum state of charge of the energy storage system at node l during the scheduling process.

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