Offshore island micro-grid energy storage configuration method and device considering steady state and transient state multi-time scale requirements

Abstract

The invention provides an offshore island micro-grid energy storage configuration method and device considering steady state and transient state multi-time scale demands, and the method comprises the steps: constructing a first operation model and a second operation model of an island micro-grid, the first operation model and the second operation model respectively reflect a relationship between physical parameters of non-energy storage equipment and energy storage equipment in the microgrid, and the energy storage equipment comprises energy type energy storage equipment and power type energy storage equipment; constructing a frequency response model of the micro-grid; constructing constraint conditions based on the physical parameters of the equipment in the micro-grid and the frequency response model; the target optimization function is solved based on the first operation model, the second operation model, the frequency response model and the constraint condition, an energy storage configuration scheme in the microgrid is obtained, and the optimization target of the target optimization function is that the cost difference before and after the energy storage equipment is configured in the microgrid is the maximum. According to the invention, the energy storage configuration cost of the offshore island micro-grid can be reduced.

Description

Technical Field

[0001] The present invention relates to the field of microgrids, and in particular to a method and device for configuring energy storage in an offshore island microgrid taking into account steady-state and transient multi-timescale requirements. Background Art

[0002] Offshore microgrids have a wide range of application scenarios, typically encompassing artificial energy islands, natural islands, large ships, offshore ranches, and various offshore platforms. Most offshore microgrids are located far from land, making connecting them to the main onshore grid via submarine cables uneconomical. Therefore, they operate as isolated microgrids, requiring guaranteed power supply self-consistency. Traditional turbine generators have drawbacks such as high power supply costs and high carbon emissions. Introducing renewable energy sources such as wind power has become an important means of addressing the energy needs of offshore island microgrids. However, the intermittent and volatile nature of wind power can impact the hourly operation and scheduling of offshore island microgrids. Furthermore, due to space constraints within offshore island microgrids, wind turbines are typically installed at a considerable distance from the offshore island microgrid via submarine cables. Harsh operating conditions at sea increase the probability of submarine cable and wind turbine failures, and these failures are difficult to troubleshoot and repair quickly, placing higher demands on offshore island microgrids for transient frequency response within seconds to minutes.

[0003] Energy storage offers high operational flexibility and can be a key technology for addressing these multi-timescale requirements, both steady-state and transient. However, the current high investment cost of energy storage leads to high energy storage deployment costs for offshore microgrids. Summary of the Invention

[0004] The present invention provides an offshore island microgrid energy storage configuration method and device suitable for taking into account steady-state and transient multi-time scale requirements, so as to solve the defect of high cost of offshore island microgrid energy storage configuration in the prior art and reduce the cost of offshore island microgrid energy storage configuration.

[0005] The present invention provides an offshore island microgrid energy storage configuration method that takes into account steady-state and transient multi-timescale requirements, the method comprising: Constructing a first operating model and a second operating model of an island microgrid, wherein the first operating model reflects the relationship between physical parameters of non-energy storage devices in the microgrid, and the second operating model reflects the relationship between physical parameters of energy storage devices, wherein the energy storage devices include energy-type energy storage devices and power-type energy storage devices; Constructing a frequency response model of the microgrid, wherein the frequency response model reflects the frequency response of each device in the microgrid after a transient fault event occurs; Establishing constraints based on physical parameters of devices in the microgrid and the frequency response model; The objective optimization function is solved based on the first operating model, the second operating model, the frequency response model, and the constraints to obtain an energy storage configuration scheme in the microgrid. The energy storage configuration scheme includes the rated power and rated energy of the energy-type energy storage device and the power-type energy storage device in the microgrid. The optimization goal of the objective optimization function is to maximize the cost difference before and after configuring the energy storage device in the microgrid.

[0006] According to a method for configuring energy storage for an offshore island microgrid taking into account steady-state and transient multi-time-scale requirements, the frequency response model includes a rotating standby gas turbine generator, a power-type energy storage device, an energy-type energy storage device, and a load in the microgrid. τ The frequency response power at time , where , τ = 0 indicates the moment when the transient fault event begins, The time required for a stationary standby turbine generator to reach target power from the start of a transient fault event; The frequency response model is: ; ; ; ; in, 、 、 and They are the frequency response reserves of rotating standby gas turbine generator, power type energy storage equipment, energy type energy storage equipment and load, 、 and are the frequency response delay times of energy storage equipment, load and spinning standby turbine generator, 、 and are the frequency complete response times of power type energy storage equipment, energy type energy storage equipment and rotating standby turbine generator, It is the time for the power type energy storage device to exit the frequency response.

[0007] According to the present invention, a method for configuring energy storage for an offshore island microgrid taking into account steady-state and transient multi-timescale requirements is provided, wherein the objective optimization function is: ; in, The equivalent annual cost of the offshore island microgrid when no energy storage is configured; The equivalent annual cost of configuring energy storage for offshore island microgrids, is the equal-year value coefficient; ; in, and are the discounted investment cost and residual value recovery benefits of energy storage equipment respectively; and are annual gas costs and carbon tax costs, respectively; and are the annual operation and maintenance costs of energy storage and turbine generator respectively.

[0008] According to a method for configuring energy storage for an offshore island microgrid that takes into account steady-state and transient multi-timescale requirements, the discounted investment cost calculation formula for the energy storage equipment in the objective optimization function is: ; The calculation formula for the output value recovery benefit of the energy storage equipment in the target optimization function is: ; in, is a collection of energy storage, and Energy storage devices e Rated energy and rated power; and Energy storage devices e The investment cost per unit rated energy and per unit rated power; For energy storage equipment e life expectancy, Energy storage equipment e The number of investments, of which Indicates not less than x The smallest integer, The expected lifespan of offshore island microgrids; The energy storage invested in this time will be replaced at the end of its expected lifespan. For energy storage equipment e The residual value rate of the last investment in energy storage equipment when the offshore island microgrid is decommissioned is recorded as ; The number of operation scheduling periods selected in the optimization model; The number of annual operation scheduling periods; I g ( t ) is a turbine generator g In the period t Gas consumption rate within For energy storage equipment e The ratio of annual operation and maintenance costs to initial investment costs; is the discount rate.

[0009] According to an offshore island microgrid energy storage configuration method taking into account steady-state and transient multi-timescale requirements provided by the present invention, the first operation model includes a network flow model, and the network flow model is: ; t Indicates the optimized scheduling period; , where Ω N Represents a collection of nodes in the network; Represents a node in the network i The set of connected nodes; Ω gt ,Ω wt ,Ω ess and Ω load Represent the collection of gas turbine generator, wind turbine generator, energy storage and load equipment respectively, g 、 w 、 e and l Represent the set Ω gt ,Ω wt ,Ω ess and Ω load Elements in P g,i ( t ), P w,i ( t ), P e,i ( t )and P l,i ( t ) represent nodes respectively i Turbine generator g , wind turbines w , energy storage e and load l In the period t The active operating power is positive when the energy storage is discharged and negative when it is charged. U i ( t ) represents a node i In the period t The voltage amplitude; G ij and B ij Respectively represent branches ij The conductance and susceptance between δ ij ( t ) represents a node i and nodes j In the period t The phase angle difference.

[0010] According to a method for configuring energy storage for an offshore island microgrid taking into account steady-state and transient multi-timescale requirements provided by the present invention, the second operation model includes a charging and discharging process model of an energy storage device, and the charging and discharging process model is: ; in, , It is a collection of energy storage devices; Energy storage device eE In the period t stored energy; and Energy storage devices eE In the period t Charging and discharging power within the Optimize the duration of the scheduling period for the system; 、 and Energy storage devices eE Self-consumption rate, charging efficiency and discharging efficiency.

[0011] The present invention also provides an offshore island microgrid energy storage configuration device that takes into account steady-state and transient multi-timescale requirements, the device comprising: An operation model construction module is used to construct a first operation model and a second operation model of the island microgrid, wherein the first operation model reflects the relationship between the physical parameters of non-energy storage devices in the microgrid, and the second operation model reflects the relationship between the physical parameters of energy storage devices, wherein the energy storage devices include energy-type energy storage devices and power-type energy storage devices; A response model building module, configured to build a frequency response model of the microgrid, wherein the frequency response model reflects the frequency response of each device in the microgrid after a transient fault event occurs; A constraint condition building module, configured to build constraint conditions based on physical parameters of devices in the microgrid and the frequency response model; an optimization module, configured to solve a target optimization function based on the first operating model, the second operating model, the frequency response model, and the constraints to obtain an energy storage configuration scheme in the microgrid, wherein the energy storage configuration scheme includes the rated power and rated energy of the energy-type energy storage device and the power-type energy storage device in the microgrid, and wherein the optimization objective of the target optimization function is to maximize the cost difference before and after configuring the energy storage device in the microgrid.

[0012] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the computer program, it implements any of the above-described methods for configuring energy storage in an offshore island microgrid that takes into account steady-state and transient multi-time-scale requirements.

[0013] The present invention also provides a non-transient computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for configuring energy storage for an offshore island microgrid taking into account steady-state and transient multi-time-scale requirements as described above is implemented.

[0014] The present invention also provides a computer program product, comprising a computer program, which, when executed by a processor, implements any of the above-described methods for configuring energy storage in an offshore island microgrid taking into account steady-state and transient multi-time-scale requirements.

[0015] The present invention provides a method and apparatus for configuring energy storage in an offshore island microgrid that takes into account both steady-state and transient multi-timescale requirements. The method and apparatus construct first and second operating models for non-energy storage devices and energy storage devices in the offshore island microgrid, and a frequency response model that reflects the frequency response of each device in the microgrid after a transient fault event. Constraints are then established based on the physical parameters of the devices in the microgrid and the frequency response model. A target optimization function is then solved based on the first and second operating models, the frequency response model, and the constraints to obtain an energy storage configuration scheme in the microgrid. The energy storage configuration scheme includes the rated power and rated capacity of energy-type and power-type energy storage devices in the microgrid. The optimization objective of the target optimization function is the cost difference before and after configuring the energy storage devices in the microgrid. In this way, different types of energy storage devices in the offshore island microgrid are configured with the goal of minimizing cost, taking into account not only the optimal scheduling of the microgrid during steady-state operation but also the frequency response of the microgrid after a transient fault event, thereby reducing the energy storage configuration cost of the offshore island microgrid. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a flow chart of the offshore island microgrid energy storage configuration method provided by the present invention taking into account steady-state and transient multi-time-scale requirements.

[0018] Figure 2This is a schematic diagram of the frequency response strategy and frequency fluctuation after a transient fault in the offshore island microgrid energy storage configuration method that takes into account steady-state and transient multi-time scale requirements provided by the present invention.

[0019] Figure 3 This is a microgrid system structure diagram of an experimental example of the offshore island microgrid energy storage configuration method taking into account steady-state and transient multi-time scale requirements provided by the present invention.

[0020] Figure 4 This is an experimental result of the offshore island microgrid energy storage configuration method considering steady-state and transient multi-time scale requirements provided by the present invention. Figure 1 .

[0021] Figure 5 This is an experimental result of the offshore island microgrid energy storage configuration method considering steady-state and transient multi-time scale requirements provided by the present invention. Figure 2 .

[0022] Figure 6 This is a structural schematic diagram of an offshore island microgrid energy storage configuration device provided by the present invention that takes into account steady-state and transient multi-time scale requirements.

[0023] Figure 7 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0025] The following combination Figure 1-5 The present invention describes the offshore island microgrid energy storage configuration method that takes into account steady-state and transient multi-time scale requirements. Figure 1 As shown, the offshore island microgrid energy storage configuration method provided by the present invention taking into account steady-state and transient multi-time scale requirements includes the following steps: S110, constructing a first operating model and a second operating model of the isolated island microgrid, wherein the first operating model reflects the relationship between physical parameters of non-energy storage devices in the microgrid, and the second operating model reflects the relationship between physical parameters of energy storage devices, wherein the energy storage devices include energy-type energy storage devices and power-type energy storage devices; S120: construct a frequency response model, where the frequency response model reflects the frequency response of each device in the microgrid after a transient fault event occurs. S130, constructing constraint conditions based on physical parameters of devices in the microgrid and a frequency response model; S140. Solve the target optimization function based on the first operating model, the second operating model, the frequency response model, and the constraints to obtain an energy storage configuration plan in the microgrid. The energy storage configuration plan includes the rated power and rated energy of the energy-type energy storage device and the power-type energy storage device in the microgrid. The optimization goal of the target optimization function is to maximize the cost difference before and after configuring the energy storage device in the microgrid.

[0026] In the method provided by the present invention, when constructing the first operating model and the second operating model, the operating parameters of the offshore island microgrid are collected. The parameters include the topological structure of the offshore island microgrid, the physical parameters of each device and the system structure parameters, the environmental parameters such as the sea wind speed, etc. When constructing the target optimization function, the cost parameters such as energy storage, gas, carbon water, equipment operation and maintenance price, discount rate, etc. are also collected.

[0027] In the method provided by the present invention, the first operating model includes a network flow model, a wind turbine model, and a gas turbine generator model. The microgrid is dominated by the gas turbine generator, and the network flow model is as follows: (1) Where: t Indicates the optimized scheduling period; , where Ω N Represents a collection of nodes in the network; Represents a node in the network i The set of connected nodes; Ω gt ,Ω wt ,Ω ess and Ω load Represent the collection of gas turbine generator, wind turbine generator, energy storage and load equipment respectively, g 、 w 、 e and l Represent the set Ω gt ,Ω wt ,Ω ess and Ω load Elements in P g,i ( t ), P w,i ( t ), P e,i ( t )and P l,i ( t ) represent nodes respectively i Turbine generator g , wind turbinesw , energy storage e and load l In the period t The active operating power is positive when the energy storage is discharged and negative when it is charged. U i ( t ) represents a node i In the period t The voltage amplitude; G ij and B ij Respectively represent branches ij The conductance and susceptance between δ ij ( t ) represents a node i and nodes j In the period t The phase angle difference.

[0028] The wind turbine model reflects the output power of the wind turbine in the maximum power point tracking mode Wind speed at current time v t The relationship between them is as follows: (2) Where: v in 、 v r and v out are the cut-in wind speed, rated wind speed and cut-out wind speed of the wind turbine respectively; Indicates wind turbine w Rated power.

[0029] The gas turbine generator model reflects the fuel consumption characteristics of the gas turbine generator, as shown in the following formula: (3) Where: Indicates the gas turbine generator in the period t fuel consumption, and Based on turbine generator g Power-fuel consumption constant obtained by fitting experimental data; For turbine generators g Rated power; Turbine generator g In the period t Power, To characterize the turbine generator g0 / 1 variable for start / stop status, a value of 1 indicates a turbine generator g In the starting state, a value of 0 indicates a turbine generator g In closed state.

[0030] The gas turbine generator model also includes the relationship between the turbine generator inertia and the rotor kinetic energy, which is expressed as follows: (4) (5) Where: and Turbine generator g Inertia and inertia time constant; For turbine generators g The rotor moment of inertia; For turbine generators g Rated apparent power; is the system synchronization angular velocity.

[0031] In the method provided by the present invention, energy storage devices are divided into two types: power-type energy storage devices (such as supercapacitors) and energy-type energy storage devices (such as lithium-ion batteries). Power-type energy storage devices do not participate in system optimization scheduling, but only participate in system inertia support and frequency response reserve. Energy-type energy storage devices participate in both optimization scheduling and, if there is a margin in energy and operating power, can also participate in system inertia support and frequency response reserve. The second operating model includes modeling that reflects the charging and discharging process of energy-type energy storage devices when participating in optimization scheduling, as shown in the following formula: (6) Where: ,in It is a collection of energy-type energy storage; Energy storage device eE In the period t stored energy; and Energy storage devices eE In the period t Charging and discharging power within the Optimize the duration of the scheduling period for the system; 、 and Energy storage devices eE Self-consumption rate, charging efficiency and discharging efficiency.

[0032] In the second operating model, the equivalent virtual inertia of the energy storage system is an adjustable quantity, as shown below: (7) Where: For energy storage e The equivalent virtual inertia of For energy storage e The equivalent virtual inertia time constant of ; For energy storage e Rated power; for The upper limit of the value.

[0033] In the method provided by the present invention, a frequency response model is also constructed, which reflects the frequency response of the microgrid after a transient fault event occurs. The frequency response model includes rotating standby gas turbine generators, power type energy storage devices, energy type energy storage devices and loads in the microgrid. τ The frequency response power at time , where , τ = 0 indicates the moment when the transient fault event begins, The time required for a stationary standby turbine generator to reach target power from the start of a transient fault event.

[0034] Specifically, in the method provided by the present invention, the multi-device coordinated frequency response strategy and frequency fluctuation schematic diagram are as follows: Figure 2 As shown, to avoid and optimize the scheduling period t Obfuscation, using symbols τ To represent the time during the frequency response process.

[0035] In the figure, τ = 0 indicates the moment when the transient fault event begins, 、 、 and They are rotating standby gas turbine generator, power-type energy storage, energy-type energy storage and load frequency response reserve. 、 and They are the frequency response delay times of energy storage, load and spinning standby turbine generator, which means the time required for each device to start power regulation from the occurrence of a transient fault event. 、 and They are the frequency full response time of power-type energy storage, energy-type energy storage and rotating standby turbine generator, which means the time required for each device to start power adjustment to reach the frequency response target power. The time it takes for power-type energy storage to exit frequency response. In offshore island microgrids, the capacity of static standby turbine generators is generally sufficient. The time required for a stationary standby turbine generator to reach target power from the start of a transient fault event.

[0036] Offshore island microgrid Total frequency response power within the time period It can be expressed as: (8) Where: 、 、 and They represent the rotating standby gas turbine generator, power type energy storage, energy type energy storage and load in the system. τ The frequency response power at the moment. Figure 2 The frequency response strategy shown can be used to obtain the expressions of various frequency response powers as follows: (9) (10) (11) (12) Frequency response target power in offshore island microgrid systems 、 、 and It is obtained by aggregating single devices, so the expressions of the above frequency response target power are as follows: (13) Where: 、 、 and They represent the collection of gas turbine generator, power type energy storage, energy type energy storage and load respectively; g 、 eP 、 eE and l The devices in the corresponding collection respectively; 、 、 and Respectively represent devices g 、 eP 、 eE and l The frequency response of the target power.

[0037] In the method provided by the present invention, in order to intuitively characterize the economic difference before and after the configuration of offshore island microgrid energy storage, the net present value index of energy storage investment is defined according to formula (14): , and taking the maximum net present value as the objective optimization function.

[0038] (14) Where: The equivalent annual cost of the offshore island microgrid when no energy storage is configured; The equivalent annual cost of configuring energy storage for the offshore island microgrid is expressed as formula (15); is the equal-year value coefficient.

[0039] (15) Where: and are the discounted investment cost and residual value recovery benefits of energy storage respectively; and are annual gas costs and carbon tax costs, respectively; and are the annual operation and maintenance costs of energy storage and turbine generator respectively.

[0040] The expressions of various costs in formula (15) are shown in formulas (16) to (21), and the expression of the equal annual value coefficient is shown in formula (22).

[0041] (16) (17) (18) (19) (20) (twenty one) (twenty two) Where: is the collection of stored energy, and ; and Energy storage e Rated energy and rated power; and Energy storage e The investment cost per unit rated energy and per unit rated power; For energy storage e life expectancy; Indicates energy storage e The number of investments, of which Indicates not less than x The smallest integer, The expected lifespan of offshore island microgrids; The energy storage invested in this time will be replaced at the end of its expected lifespan. For energy storage e The residual value rate of the last investment in energy storage may still have a remaining life when the offshore island microgrid is decommissioned, and the recovery rate at this time is recorded as , which can be estimated by the remaining life of the energy storage and the corresponding health status; The number of operation scheduling periods selected in the optimization model; The number of annual operation scheduling periods; is the unit gas consumption cost; I g ( t ) is a turbine generator g In the period t Gas consumption rate within Optimize the duration of the scheduling period for the system; is the unit carbon emission cost; The conversion rate of carbon emissions to gas; is the operation and maintenance cost of the turbine generator per unit output power; For energy storage e The ratio of annual operation and maintenance costs to initial investment costs; is the discount rate.

[0042] To ensure the feasibility of the energy storage configuration solution obtained by solving the objective optimization function, the method provided by the present invention constructs constraints based on the first operating model, the second operating model, and the frequency response model. These constraints can limit the feasibility of the solution obtained during the objective optimization function solution. In the method provided by the present invention, the constraints include system network flow constraints, energy storage constraints, wind turbine constraints, gas turbine generator constraints, load constraints, and frequency constraints, each of which is described below.

[0043] 1) System network trends Offshore island microgrids need to monitor node voltage Make the constraints as follows: (twenty three) Where: and Respectively upper and lower limits.

[0044] 2) Energy storage The upper and lower limits of energy storage configuration capacity are as follows: (twenty four) (25) Where, and Represents energy storage devices e The upper limit of rated energy and rated power.

[0045] The energy-to-power ratio of energy storage products also has certain limitations, as shown below: (26) Where: and Energy storage e The upper and lower limits of the energy-to-power ratio are related to the energy storage type.

[0046] Energy storage during the period t Charging power and discharge power The following constraints need to be met: (27) (28) (29) Where: Energy storage eE Rated power; and Energy storage eE In the period t 0 / 1 variables for internal charge and discharge states.

[0047] Energy storage has energy boundary constraints (30), as shown below: (30) Where: and Energy storage eE The maximum and minimum state of charge limits.

[0048] Energy storage needs to complete a charge and discharge cycle in each scheduling cycle, so that the energy at the initial and final states is and To achieve equilibrium, the constraints are as follows: (31) Energy storage transient frequency response reserve The following constraints need to be met: (32) (33) (34) Where: Energy storage eE The frequency response limiting coefficient, Energy storage eE During the scheduling period t The power inside.

[0049] Power storage during the dispatch period t Frequency response reserve within The following constraints should be met: (35) (36) Where: and Power type energy storage eP Rated power and rated energy; Power-type energy storage eP The frequency response limiting coefficient of Power-type energy storage eP Maintaining state of charge.

[0050] 3) Wind turbines Active power output of wind turbine The following constraints should be met: (37) 4) Gas turbine generator The operating power of the gas turbine generator should meet the following constraints: (38) (39) Where: and Turbine generator g Rate limits for ramping up and ramping down.

[0051] Turbine generator during the period t Transient frequency response reserve It is also limited by steady-state operating power and frequency response limitations as shown below: (40) (41) Where: For turbine generators g Rated power; For turbine generators g Frequency response limiting coefficient of the speed regulator.

[0052] 5) Load Load in period t Frequency response reserve The following constraints must be met: (42) Where: for The upper limit value of , in this paper, is taken as the maximum load shedding capacity of the system.

[0053] 6) Frequency constraints under wind turbine off-grid transient faults Based on the proposed multi-device coordinated frequency response strategy for offshore island microgrids, the system frequency constraints under wind turbine off-grid failure are derived. The frequency change rate should satisfy the following constraints: (43) Where: is the initial frequency change rate under transient fault events; for The maximum allowed value of is the total inertia of the system; is the nominal frequency of the system.

[0054] The quasi-steady-state frequency deviation constraints of the offshore island microgrid are as follows: (44) Based on the proposed multi-device coordinated frequency response strategy, the maximum frequency deviation constraint of the offshore island microgrid is as follows: (45) (46) Where: || x ||2 means x The second norm of ; H gt 、 H Eess 、 H Pess They are the inertia of gas turbine generator, energy type energy storage, and power type energy storage; is the maximum tolerance of system frequency deviation, 、 、 、 、 and To simplify the coefficients, the values of the coefficients are as follows: , , , , , .

[0055] Based on the above model and constraints, the model for optimizing energy storage configuration in the method provided by the present invention can be expressed as: (47) It can be seen that the optimization model shown in formula (47) is a mixed integer quadratic convex programming problem. It can be solved by using precise methods such as branch and bound method and cutting plane method, or heuristic algorithms such as genetic algorithm, particle swarm algorithm, simulated annealing algorithm, hybrid improved algorithms based on the above algorithms, and calling external mature commercial solvers.

[0056] In order to verify the effectiveness of the method provided by the present invention, a certain offshore island microgrid is used as a research object for verification. The system structure and equipment parameters of the research object are as follows: Figure 3 As shown, the offshore island microgrid has a lifespan of 30 years. The system is equipped with four gas turbine generators (GTG1-GTG4) for spinning reserve, along with sufficient static reserve gas turbine generators. The offshore island microgrid plans to invest in supercapacitors and lithium-ion batteries. To validate the superiority of the method provided by this invention, six energy storage configuration strategies, shown in Table 1, were compared.

[0057] Table 1

[0058] The energy storage configuration results under different strategies are as follows: Figure 4 As shown in Figure 2, the net present value and wind curtailment rate are as follows: Figure 5 As shown in the figure, the net present values of strategies 3 to 6 are improved by 4.9%, 10.5%, 3.2%, and 3.1%, respectively, compared to strategy 2 in the existing literature, while the wind curtailment rates are reduced by 4.9%, 5.7%, 3.6%, and 2.2%, respectively. This verifies the superiority of the energy storage configuration method proposed in this paper. Among them, strategy 4 achieves the highest net present value and the lowest wind curtailment rate. Therefore, the energy storage configuration corresponding to strategy 4 is recommended in this example.

[0059] The following describes the offshore island microgrid energy storage configuration device that takes into account steady-state and transient multi-time-scale requirements provided by the present invention. The offshore island microgrid energy storage configuration device that takes into account steady-state and transient multi-time-scale requirements described below and the offshore island microgrid energy storage configuration method that takes into account steady-state and transient multi-time-scale requirements described above can be referenced to each other. Figure 6 As shown, the offshore island microgrid energy storage configuration device provided by the present invention taking into account steady-state and transient multi-time scale requirements includes the following modules: An operation model construction module 610 is used to construct a first operation model and a second operation model of the isolated island microgrid, wherein the first operation model reflects the relationship between the physical parameters of non-energy storage devices in the microgrid, and the second operation model reflects the relationship between the physical parameters of energy storage devices, which include energy storage devices and power storage devices; A response model building module 620 is used to build a frequency response model of the microgrid, which reflects the frequency response of each device in the microgrid after a transient fault event occurs; A constraint condition building module 630 is used to build constraint conditions based on physical parameters of devices in the microgrid and a frequency response model; Optimization module 640 is configured to solve a target optimization function based on the first operating model, the second operating model, the frequency response model, and the constraints to obtain an energy storage configuration solution in the microgrid. The energy storage configuration solution includes the rated power and rated energy of the energy-type energy storage devices and the power-type energy storage devices in the microgrid. The optimization objective of the target optimization function is to maximize the cost difference before and after configuring the energy storage devices in the microgrid.

[0060] Figure 7 An example of a physical structure diagram of an electronic device is shown below. Figure 7 As shown, the electronic device may include: a processor (processor) 710 , a communication interface (Communications Interface) 720 , a memory (memory) 730 and a communication bus 740 , wherein the processor 710 , the communication interface 720 and the memory 730 communicate with each other via the communication bus 740 . The processor 710 can call the logic instructions in the memory 730 to execute an offshore island microgrid energy storage configuration method that takes into account steady-state and transient multi-time scale requirements. The method includes: constructing a first operating model and a second operating model of the isolated island microgrid, the first operating model reflects the relationship between the physical parameters of non-energy storage devices in the microgrid, and the second operating model reflects the relationship between the physical parameters of the energy storage devices, and the energy storage devices include energy-type energy storage devices and power-type energy storage devices; constructing a frequency response model of the microgrid, the frequency response model reflects the frequency response of each device in the microgrid after a transient fault event occurs; constructing constraints based on the physical parameters of the devices in the microgrid and the frequency response model; solving the target optimization function based on the first operating model, the second operating model, the frequency response model and the constraints to obtain an energy storage configuration scheme in the microgrid, the energy storage configuration scheme includes the rated power and rated energy of the energy-type energy storage devices and the power-type energy storage devices in the microgrid, and the optimization goal of the target optimization function is to maximize the cost difference before and after configuring the energy storage devices in the microgrid.

[0061] Furthermore, the logic instructions in the aforementioned memory 730 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product, stored in a storage medium, includes instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0062] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the offshore island microgrid energy storage configuration method taking into account steady-state and transient multi-time scale requirements provided by the above methods. The method includes: constructing a first operating model and a second operating model of the isolated island microgrid, the first operating model reflects the relationship between the physical parameters of non-energy storage devices in the microgrid, and the second operating model reflects the relationship between the physical parameters of the energy storage devices, and the energy storage devices include energy-type energy storage devices and power-type energy storage devices; constructing a frequency response model of the microgrid, the frequency response model reflects the frequency response of each device in the microgrid after a transient fault event occurs; constructing constraints based on the physical parameters of the devices in the microgrid and the frequency response model; solving the target optimization function based on the first operating model, the second operating model, the frequency response model and the constraints to obtain an energy storage configuration scheme in the microgrid, the energy storage configuration scheme including the rated power and rated energy of the energy-type energy storage devices and the power-type energy storage devices in the microgrid, and the optimization goal of the target optimization function is to maximize the cost difference before and after configuring the energy storage devices in the microgrid.

[0063] On the other hand, the present invention also provides a non-transient computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the offshore island microgrid energy storage configuration method taking into account steady-state and transient multi-time scale requirements provided by the above-mentioned methods, the method comprising: constructing a first operating model and a second operating model of the isolated island microgrid, the first operating model reflecting the relationship between physical parameters of non-energy storage devices in the microgrid, and the second operating model reflecting the relationship between physical parameters of energy storage devices, the energy storage devices including energy-type energy storage devices and power-type energy storage devices; constructing a frequency response model of the microgrid, the frequency response model reflecting the frequency response of each device in the microgrid after a transient fault event occurs; constructing constraints based on the physical parameters of the devices in the microgrid and the frequency response model; solving the target optimization function based on the first operating model, the second operating model, the frequency response model and the constraints to obtain an energy storage configuration scheme in the microgrid, the energy storage configuration scheme including the rated power and rated energy of the energy-type energy storage devices and the power-type energy storage devices in the microgrid, and the optimization goal of the target optimization function is to maximize the cost difference before and after configuring the energy storage devices in the microgrid.

[0064] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0065] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for configuring energy storage for an offshore island microgrid taking into account steady-state and transient multi-timescale requirements, characterized in that: The method comprises: Constructing a first operating model and a second operating model of an island microgrid, wherein the first operating model reflects the relationship between physical parameters of non-energy storage devices in the microgrid, and the second operating model reflects the relationship between physical parameters of energy storage devices, wherein the energy storage devices include energy-type energy storage devices and power-type energy storage devices; Constructing a frequency response model of the microgrid, wherein the frequency response model reflects the frequency response of each device in the microgrid after a transient fault event occurs; Establishing constraints based on physical parameters of devices in the microgrid and the frequency response model; The objective optimization function is solved based on the first operating model, the second operating model, the frequency response model, and the constraints to obtain an energy storage configuration scheme in the microgrid. The energy storage configuration scheme includes the rated power and rated energy of the energy-type energy storage device and the power-type energy storage device in the microgrid. The optimization goal of the objective optimization function is to maximize the cost difference before and after configuring the energy storage device in the microgrid.

2. The offshore island microgrid energy storage configuration method considering steady-state and transient multi-timescale requirements according to claim 1 is characterized in that: The frequency response model includes the rotating standby gas turbine generator, power type energy storage device, energy type energy storage device and load in the microgrid. τ The frequency response power at time , where , τ = 0 indicates the moment when the transient fault event begins, The time required for a stationary standby turbine generator to reach target power from the start of a transient fault event; The frequency response model is: ； ； ； ； in, 、 、 and They are the frequency response reserves of rotating standby gas turbine generator, power type energy storage equipment, energy type energy storage equipment and load, 、 and are the frequency response delay times of energy storage equipment, load and spinning standby turbine generator, 、 and are the frequency complete response times of power type energy storage equipment, energy type energy storage equipment and rotating standby turbine generator, It is the time for the power type energy storage device to exit the frequency response.

3. The offshore island microgrid energy storage configuration method considering steady-state and transient multi-timescale requirements according to claim 1 is characterized in that: The objective optimization function is: ； in, The equivalent annual cost of the offshore island microgrid when no energy storage is configured; The equivalent annual cost of configuring energy storage for offshore island microgrids, is the equal-year value coefficient; ； in, and are the discounted investment cost and residual value recovery benefits of energy storage equipment respectively; and are annual gas costs and carbon tax costs, respectively; and are the annual operation and maintenance costs of energy storage and turbine generator respectively.

4. The offshore island microgrid energy storage configuration method considering steady-state and transient multi-timescale requirements according to claim 3 is characterized in that: The calculation formula for the discounted investment cost of energy storage equipment in the objective optimization function is: ； The calculation formula for the output value recovery benefit of the energy storage equipment in the target optimization function is: ； in, is a collection of energy storage, and Energy storage devices e Rated energy and rated power; and Energy storage devices e The investment cost per unit rated energy and per unit rated power; For energy storage equipment e life expectancy, Energy storage equipment e The number of investments, of which Indicates not less than x The smallest integer, The expected lifespan of offshore island microgrids; The energy storage invested in this time will be replaced at the end of its expected lifespan. For energy storage equipment e The residual value rate of the last investment in energy storage equipment when the offshore island microgrid is decommissioned is recorded as ; The number of operation scheduling periods selected in the optimization model; The number of annual operation scheduling periods; I g ( t ) is a turbine generator g In the period t Gas consumption rate within For energy storage equipment e The ratio of annual operation and maintenance costs to initial investment costs; is the discount rate.

5. The offshore island microgrid energy storage configuration method considering steady-state and transient multi-timescale requirements according to claim 1 is characterized in that: The first operation model includes a network flow model, and the network flow model is: ； t Indicates the optimized scheduling period; , where Ω N Represents a collection of nodes in the network; Represents a node in the network i The set of connected nodes; Ω gt ,Ω wt ,Ω ess and Ω load Represent the collection of gas turbine generator, wind turbine generator, energy storage and load equipment respectively, g 、 w 、 e and l Represent the set Ω gt ,Ω wt ,Ω ess and Ω load Elements in P g,i ( t ), P w,i ( t ), P e,i ( t )and P l,i ( t ) represent nodes respectively i Turbine generator g , wind turbines w , energy storage e and load l In the period t The active operating power is positive when the energy storage is discharged and negative when it is charged. U i ( t ) represents a node i In the period t The voltage amplitude; G ij and B ij Respectively represent branches ij The conductance and susceptance between δ ij ( t ) represents a node i and nodes j In the period t The phase angle difference.

6. The offshore island microgrid energy storage configuration method considering steady-state and transient multi-timescale requirements according to claim 1 is characterized in that: The second operation model includes a charging and discharging process model of the energy storage device, and the charging and discharging process model is: ； in, , It is a collection of energy storage devices; Energy storage device eE In the period t stored energy; and They are energy storage devices eE in time period t Charging and discharging power within the Optimize the duration of the scheduling period for the system; 、 and Energy storage devices eE Self-consumption rate, charging efficiency and discharging efficiency.

7. An offshore island microgrid energy storage configuration device that takes into account steady-state and transient multi-timescale requirements, characterized in that: The device comprises: An operation model construction module is used to construct a first operation model and a second operation model of the island microgrid, wherein the first operation model reflects the relationship between the physical parameters of non-energy storage devices in the microgrid, and the second operation model reflects the relationship between the physical parameters of energy storage devices, wherein the energy storage devices include energy-type energy storage devices and power-type energy storage devices; A response model building module, configured to build a frequency response model of the microgrid, wherein the frequency response model reflects the frequency response of each device in the microgrid after a transient fault event occurs; A constraint condition building module, configured to build constraint conditions based on physical parameters of devices in the microgrid and the frequency response model; an optimization module, configured to solve a target optimization function based on the first operating model, the second operating model, the frequency response model, and the constraints to obtain an energy storage configuration scheme in the microgrid, wherein the energy storage configuration scheme includes the rated power and rated energy of the energy-type energy storage device and the power-type energy storage device in the microgrid, and wherein the optimization objective of the target optimization function is to maximize the cost difference before and after configuring the energy storage device in the microgrid.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the offshore island microgrid energy storage configuration method taking into account steady-state and transient multi-time-scale requirements as described in any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the offshore island microgrid energy storage configuration method taking into account steady-state and transient multi-time-scale requirements as described in any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the offshore island microgrid energy storage configuration method taking into account steady-state and transient multi-time-scale requirements as described in any one of claims 1 to 6 is implemented.

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