Micro-grid energy storage optimal configuration method and system

Abstract

The invention provides a micro-grid energy storage optimal configuration method and system, and relates to the technical field of energy storage system optimization. According to the method provided by the invention, a micro-grid energy storage configuration and optimization scheduling model taking the energy storage network construction capability of the micro-grid as an evaluation standard is established; establishing a target function by taking the overall operation benefit optimization of the micro-grid as a target; determining a plurality of constraint conditions based on the micro-grid energy storage configuration and the optimal scheduling model; according to the actual parameters of the micro-grid, the objective function and the multiple constraint conditions are solved, the optimal configuration and scheduling result of the micro-grid is obtained, the method provided by the invention can determine the optimal configuration and scheduling result according to the actual scene of the micro-grid, and then scheduling strategies corresponding to different time periods are obtained. The energy storage investment and construction cost can be reduced, the micro-grid operation cost can be reduced, the new energy utilization rate can be improved, meanwhile, it is guaranteed that the system has the enough inertia level and frequency adjusting capacity under the disturbance condition, and the use requirements of users in different use scenes are met.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage system optimization, and in particular to a microgrid energy storage optimization configuration method and system. Background Art

[0002] With the continuous increase in energy consumption and environmental pressure, human society's demand for energy systems is also constantly updating. Controlling electricity costs, promoting energy structure transformation, and improving the utilization of renewable resources have become the consensus of the international community. However, the large-scale access to intermittent and uncertain renewable energy sources such as wind and solar energy in the power grid will not only increase the difficulty of scheduling and affect the quality of power, but also increase the risk of system safety and stability. In this case, microgrid technology that integrates energy storage, new energy and intelligent control strategies has emerged. Through optimized scheduling, microgrids can autonomously and flexibly realize energy production, storage and consumption, ensuring the efficient use of new energy.

[0003] At present, wind and solar energy are often connected to microgrids in a grid-following manner to inject power into the system. Energy storage devices have fast response speeds and high energy density, and can provide flexible reserve power and dispatch capabilities for microgrids when there is an imbalance between the output power of new energy and the power demand of loads. As the penetration rate of new energy continues to increase and the proportion of synchronous generators decreases, microgrids present weak grid characteristics. New energy power generation units operating in a grid-following manner are not stable enough, and it is urgent to give full play to the grid-building capabilities of energy storage devices.

[0004] Therefore, a method and system for optimizing the configuration of microgrid energy storage is urgently needed to achieve the optimal configuration of microgrid energy storage, thereby optimizing the capacity of grid-type energy storage and reducing construction costs. This will achieve the coordination of grid-type energy storage and new energy in the microgrid and enhance the stability of the system. Summary of the invention

[0005] The embodiment of the present invention provides a microgrid energy storage optimization configuration method and system, which can realize the optimization configuration of microgrid energy storage, thereby optimizing the grid-type energy storage capacity and reducing the construction cost. Thus, the coordination of grid-type energy storage and new energy in the microgrid is realized, and the stability of the system is enhanced.

[0006] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0007] In a first aspect, a method for optimizing energy storage configuration of a microgrid is provided, the method comprising: establishing a microgrid energy storage configuration and optimization scheduling model with the energy storage networking capability of the microgrid as an evaluation standard; establishing an objective function with the overall operation benefit of the microgrid as the goal, wherein the optimal operation benefit includes maximizing the utilization rate of new energy, minimizing the energy storage investment cost and minimizing the power generation cost; determining multiple constraints based on the microgrid energy storage configuration and optimization scheduling model, wherein the multiple constraints include a first constraint with grid power balance as a constraint, a second constraint with the available power of new energy as a constraint, a third constraint with the transmission power of the interconnection line as a constraint, a fourth constraint with the operating capability of the synchronous generator as a constraint, a fifth constraint with the energy storage function as a constraint, a sixth constraint with the rotational kinetic energy of the networking type energy storage support characteristics as a constraint, and a seventh constraint with the standby capacity as a constraint; solving the objective function and multiple constraints according to the actual parameters of the microgrid to obtain the optimal configuration and scheduling results of the microgrid;

[0008] Among them, the objective function is:

[0009]

[0010] Among them, C In is the annual value of the initial investment cost; The operating costs of grid-type energy storage; is the operating cost of synchronous generator at different output powers; is the wind power operation cost in the tth time period, is the photovoltaic operation cost in the tth time period; is the power purchase cost of the power grid in the tth time period; F t WT F is the cost of wind curtailment; t PV The cost of abandoned light.

[0011] In a possible implementation of the first aspect, the annual value of the initial investment cost C In The formula for determining is:

[0012] Annual value of initial investment cost C In The formula for determining is:

[0013]

[0014] Among them, K P , K E are the unit costs of energy storage power capacity and energy capacity respectively; r is the base discount rate; n e is the operating life of the energy storage system; P e E is the energy storage rated power; e is the rated capacity of energy storage;

[0015] Operating costs of grid-connected energy storage The formula for determining is:

[0016]

[0017] Operating costs of synchronous generators at different output powers The formula for determining is:

[0018]

[0019] Among them, α Gfm , β Gfm and γ Gfm are the operating parameters of grid-type energy storage; α Gen , β Gen and γ Gen are the operating parameters of the synchronous generator respectively; P Gfm,t is the actual interaction power of the grid-type energy storage during period t; P Gen,t is the actual output power of the generator during period t;

[0020] Wind power operation cost in time period t The formula for determining is:

[0021]

[0022] PV operation cost in time period t The formula for determining is:

[0023]

[0024] The cost of purchasing electricity from the power grid during the tth time period The formula for determining is:

[0025]

[0026] c WT is the unit price of wind turbine power generation; c PV is the unit price of photovoltaic power generation; c Grid is the grid-side electricity price; is the available power of wind power; is the photovoltaic available power; P Grid,t is the power purchased by the power grid during period t;

[0027] The wind curtailment cost F in the tth time period t WT The formula for determining is:

[0028]

[0029] α WTP is the penalty cost coefficient for unit wind curtailment; WT,t is the actual wind power during period t;

[0030] The cost of abandoned light in the tth time period F t PV The formula for determining is:

[0031]

[0032] α PV P is the unit abandoned light penalty cost coefficient; PV,t is the actual photovoltaic power during period t.

[0033] In a possible implementation manner of the first aspect, the first constraint condition includes:

[0034]

[0035] P Load,t , is the load power during the period tt.

[0036] In a possible implementation manner of the first aspect, the second constraint condition includes:

[0037]

[0038] In a possible implementation manner of the first aspect, the third constraint condition includes:

[0039]

[0040] in, It is the maximum value of the transmission power of the tie line between the microgrid and the upper grid.

[0041] In a possible implementation manner of the first aspect, the fourth constraint condition includes:

[0042]

[0043] is the lower limit of the output power of the synchronous generator; is the upper limit of the output power of the synchronous generator; P Gen,t-1 is the actual output power of the generator during period t-1; is the maximum climbing power of the generator.

[0044] In a possible implementation manner of the first aspect, the fifth constraint condition includes:

[0045]

[0046] Among them, E n,t is the energy storage capacity at time t; E n,t-1is the energy storage capacity at time t-1; is the charging power; is the discharge power; Indicates the charging operation status of the grid-connected energy storage at time t; Represents the discharge operation state of the grid-type energy storage at time t; η d is the discharge efficiency of the energy storage system; η c The charging efficiency of the energy storage system; is the lower limit of the energy storage capacity of the energy storage system; The upper limit of the energy storage capacity of the energy storage system; It is the upper limit of energy storage charging and discharging power.

[0047] In a possible implementation manner of the first aspect, the sixth constraint condition includes:

[0048]

[0049] Among them, R oCoF is the frequency change rate; ΔP loss is the power shortage; is the maximum frequency change rate; f0 is the rated frequency; E sys is the rotational kinetic energy of the energy storage system; H Gen is the inertia time constant of the synchronous generator; is the rated power; is the inertia time constant of the grid-type energy storage in the tth time period; It is the rated power of grid-type energy storage; is the rotational kinetic energy stored in the microgrid during the tth time period; H min is the lower limit of the energy storage inertia time constant; H max is the upper limit of the energy storage inertia time constant; P Gfm,t Transmit power to the energy storage interconnection line, is the maximum transmission power of the energy storage interconnection line.

[0050] In a possible implementation manner of the first aspect, the seventh constraint condition includes:

[0051]

[0052] is the total reserve capacity of the microgrid; is the reserve capacity of the synchronous generator in time period t; For the backup demand of energy storage system.

[0053] The beneficial effects of the present invention are as follows: the method provided by the present invention introduces the energy storage rated power and rated capacity as decision variables into the objective function, and forms multiple constraints based on the reserve inertia and energy storage power of the grid-forming energy storage. The proposed microgrid energy storage configuration and day-ahead optimization scheduling strategy taking into account the energy storage grid-forming capability can determine the optimization configuration and scheduling results according to the actual grid scenario, and then obtain the scheduling strategy corresponding to different time periods. While reducing the energy storage investment and construction costs, reducing the microgrid operating costs, and improving the utilization rate of new energy, it can ensure that the system has sufficient inertia level and frequency regulation capabilities under disturbance conditions to meet the user's usage needs in different usage scenarios.

[0054] In a second aspect, an embodiment of the present invention provides a microgrid energy storage optimization configuration system, the system comprising: a model building module, used to establish a microgrid energy storage configuration and optimization scheduling model with the energy storage networking capability of the microgrid as the evaluation standard; a function building module, used to establish an objective function with the overall operation benefit of the microgrid as the goal, wherein the optimal operation benefit includes maximizing the utilization rate of new energy, minimizing the energy storage investment cost and minimizing the power generation cost; a condition determination module, used to determine multiple constraints based on the microgrid energy storage configuration and optimization scheduling model, wherein the multiple constraints include a first constraint with grid power balance as the constraint, a second constraint with new energy available power as the constraint, a third constraint with interconnection line transmission power as the constraint, a fourth constraint with synchronous generator operation capability as the constraint, a fifth constraint with energy storage function as the constraint, a sixth constraint with rotational kinetic energy of the networking type energy storage support characteristics as the constraint, and a seventh constraint with spare capacity as the constraint; a result determination module, used to solve the objective function and the multiple constraints according to the actual parameters of the microgrid to obtain the optimization configuration and scheduling results of the microgrid;

[0055] Among them, the objective function is:

[0056]

[0057] Among them, C In is the annual value of the initial investment cost; The operating costs of grid-type energy storage; is the operating cost of synchronous generator at different output powers; is the wind power operation cost in the tth time period, is the photovoltaic operation cost in the tth time period; is the power purchase cost of the power grid in the tth time period; F t WT F is the cost of wind curtailment; t PV The cost of abandoned light.

[0058] According to a third aspect, an electronic device is provided, comprising a memory and one or more processors; the memory is coupled to the processor; wherein the memory stores computer program code, the computer program code comprises computer instructions, and when the computer instructions are executed by the processor, the electronic device executes a method as in any implementation of the first aspect.

[0059] According to a fourth aspect, a computer-readable storage medium is provided, comprising computer instructions. When the computer instructions are executed on an electronic device, the electronic device executes the method in any implementation of the first aspect.

[0060] According to a fifth aspect, a computer program product is provided. When the computer program product is run on a computer, the computer is enabled to execute the method in any implementation of the first aspect.

[0061] It can be understood that the beneficial effects that can be achieved by the system of the second aspect, the electronic device of the third aspect, the computer-readable storage medium of the fourth aspect, and the computer program product of the fifth aspect provided above can be referred to the beneficial effects in the first aspect and any possible design method thereof, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 A schematic diagram of the hardware structure of an electronic device shown in an embodiment of the present invention;

[0063] Figure 2 A flow chart of a microgrid energy storage optimization configuration method and system shown in an embodiment of the present invention;

[0064] Figure 3 The figure is a schematic diagram of the hardware structure of a configuration system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0065] The technical solution in the embodiment of the present invention will be described below in conjunction with the accompanying drawings in the embodiment of the present invention. Among them, in the description of the present invention, unless otherwise specified, " / " indicates that the objects associated before and after are in an "or" relationship, for example, A / B can represent A or B; the "or" in the present invention is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. And, in the description of the present invention, unless otherwise specified, "multiple" means two or more than two. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items.

[0066] In addition, in order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, the words "first", "second", etc. are used to distinguish the same items or similar items with substantially the same functions and effects. Those skilled in the art can understand that the words "first", "second", etc. do not limit the quantity and execution order, and the words "first", "second", etc. do not necessarily limit the difference.

[0067] Meanwhile, in the embodiments of the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way for easy understanding.

[0068] With the continuous increase in energy consumption and environmental pressure, human society's demand for energy systems is also constantly updating. Controlling electricity costs, promoting energy structure transformation, and improving the utilization of renewable resources have become the consensus of the international community. However, the large-scale access to intermittent and uncertain renewable energy sources such as wind and solar energy in the power grid will not only increase the difficulty of scheduling and affect the quality of power, but also increase the risk of system safety and stability. In this case, microgrid technology that integrates energy storage, new energy and intelligent control strategies has emerged. Through optimized scheduling, microgrids can autonomously and flexibly realize energy production, storage and consumption, ensuring the efficient use of new energy.

[0069] At present, wind and solar energy are often connected to microgrids in a grid-following manner to inject power into the system. Energy storage devices have fast response speeds and high energy density, and can provide flexible reserve power and dispatch capabilities for microgrids when there is an imbalance between the output power of new energy and the power demand of loads. As the penetration rate of new energy continues to increase and the proportion of synchronous generators decreases, microgrids present weak grid characteristics. New energy power generation units operating in a grid-following manner are not stable enough, and it is urgent to give full play to the grid-building capabilities of energy storage devices.

[0070] Therefore, a method and system for optimizing the configuration of microgrid energy storage is urgently needed to achieve the optimal configuration of microgrid energy storage, thereby optimizing the capacity of grid-type energy storage and reducing construction costs. This will achieve the coordination of grid-type energy storage and new energy in the microgrid and enhance the stability of the system.

[0071] In view of this, an embodiment of the present invention provides a method for optimizing energy storage configuration of a microgrid, the method comprising: establishing a microgrid energy storage configuration and optimization scheduling model with the energy storage networking capability of the microgrid as an evaluation standard; establishing an objective function with the overall operation benefit of the microgrid as the goal, wherein the optimal operation benefit includes maximizing the utilization rate of new energy, minimizing the energy storage investment cost and minimizing the power generation cost; determining multiple constraints based on the microgrid energy storage configuration and optimization scheduling model, wherein the multiple constraints include a first constraint with grid power balance as a constraint, a second constraint with new energy available power as a constraint, a third constraint with interconnection line transmission power as a constraint, a fourth constraint with synchronous generator operation capability as a constraint, a fifth constraint with energy storage function as a constraint, a sixth constraint with rotational kinetic energy of networking type energy storage support characteristics as a constraint and a seventh constraint with standby capacity as a constraint; solving the objective function and multiple constraints according to actual parameters of the microgrid to obtain the optimal configuration and scheduling results of the microgrid.

[0072] The method provided by the present invention introduces the energy storage rated power and rated capacity as decision variables into the objective function, and forms multiple constraints based on the reserve inertia and energy storage power of the grid-type energy storage. The proposed microgrid energy storage configuration and day-ahead optimization scheduling strategy can determine the optimization configuration and scheduling results according to the actual scenario of the power grid, and then obtain the scheduling strategy corresponding to different time periods. While reducing the energy storage investment and construction costs, reducing the microgrid operating costs, and improving the utilization rate of new energy, it can ensure that the system has sufficient inertia level and frequency regulation capabilities under disturbance conditions to meet the user's usage needs in different usage scenarios.

[0073] In some embodiments, the microgrid energy storage optimization configuration method provided in the embodiments of the present invention may be executed by a microgrid energy storage optimization configuration system 100 (hereinafter referred to as configuration system 100). As an example, the configuration system 100 may be any electronic device 200 with data processing capabilities, such as a general-purpose computer, a personal computer, a laptop, a switch, or a tablet computer, etc. The specific implementation of the purchase list configuration system 100 is not limited here.

[0074] Figure 1 The hardware structure diagram of the electronic device provided by the embodiment of the present invention is shown. The electronic device 200 includes a processor 210, a memory 220 and a communication interface 230.

[0075] The processor 210 may include one or more processing cores. The processor 210 uses various interfaces and lines to connect various parts in the electronic device 200, and executes various functions and processes data of the electronic device 200 by running or executing instructions, programs, code sets or instruction sets stored in the memory 220, and calling data stored in the memory 220. Optionally, the processor 210 can be implemented in at least one hardware form of a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processing (DSP), a field-programmable gate array (FPGA), and a programmable logic array (PLA).

[0076] The memory 220 may include a random access memory (RAl) or a read-only memory (ROL). Optionally, the memory 220 includes a non-transitory computer-readable storage medium (non-transitory colputer-readable storage lediul). The memory 220 may be used to store instructions, programs, codes, code sets or instruction sets. The memory 220 may include a program storage area. The program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (such as a data acquisition function, a density control function, etc.), instructions for implementing the above-mentioned various method embodiments, etc.

[0077] The communication interface 230 is used to communicate with other devices, equipment or communication networks, such as data storage devices, image processing equipment or Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.

[0078] In physical implementation, the above-mentioned components (such as processor 210, memory 220 and communication interface 230) can be components in the same device (such as a laptop). Alternatively, at least two of the components can be set in the same device, that is, as different components in one device, such as a deployment method similar to devices or components in a distributed system.

[0079] It is to be understood that the structure illustrated in this embodiment does not constitute a specific limitation on the electronic device 200. In other embodiments of the present invention, the electronic device 200 may include more or fewer components than those illustrated, or combine certain components, or separate certain components, or arrange the components differently. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0080] The following describes a method for optimizing energy storage configuration in a microgrid provided by an embodiment of the present invention in conjunction with the accompanying drawings.

[0081] Figure 2 A flowchart of a microgrid energy storage optimization configuration method provided by an embodiment of the present invention. Optionally, the method can be Figure 1 The electronic device 200 shown is executed, that is, executed by the configuration system 100. The method may include the following steps:

[0082] S1. Establish a microgrid energy storage configuration and optimization scheduling model with the microgrid energy storage networking capability as the evaluation standard.

[0083] Specifically, the energy storage networking capability of a microgrid refers to the ability of the energy storage system to build and maintain stable voltage and frequency in the microgrid through specific control technologies and equipment, thereby supporting the safe and smooth operation of the microgrid.

[0084] S2. Establish an objective function with the goal of optimizing the overall operating benefits of the microgrid, where the optimal operating benefits include maximizing the utilization rate of new energy, minimizing the energy storage investment cost, and minimizing the power generation cost.

[0085] Among them, the objective function is:

[0086]

[0087] Among them, C In is the annual value of the initial investment cost; The operating costs of grid-type energy storage; is the operating cost of synchronous generator at different output powers; is the wind power operation cost in the tth time period, is the photovoltaic operation cost in the tth time period; is the power purchase cost of the power grid in the tth time period; F t WT F is the cost of wind curtailment; t PV The cost of abandoned light.

[0088] Specifically, the objective function aims to minimize the overall operating cost and energy storage construction cost of the microgrid during period t and to improve the absorption capacity of wind power and photovoltaic power.

[0089] In some embodiments, the annual value of the initial investment cost C In The formula for determining is:

[0090]

[0091] Among them, K P , K E are the unit costs of energy storage power capacity and energy capacity respectively; r is the base discount rate; n e is the operating life of the energy storage system; P e E is the energy storage rated power; e is the rated capacity of energy storage; the operating cost of grid-type energy storage The formula for determining is:

[0092]

[0093] Operating costs of synchronous generators at different output powers The formula for determining is:

[0094]

[0095] Among them, α Gfm , β Gfm and γ Gfm are the operating parameters of grid-type energy storage; α Gen , β Gen and γ Gen are the operating parameters of the synchronous generator respectively; P Gfm,t is the actual interaction power of the grid-type energy storage during period t; P Gen,t is the actual output power of the generator during period t.

[0096] Wind power operation cost in time period t The formula for determining is:

[0097]

[0098] PV operation cost in time period t The formula for determining is:

[0099]

[0100] The cost of purchasing electricity from the power grid during the tth time period The formula for determining is:

[0101]

[0102] c WT is the unit price of wind turbine power generation; c PV is the unit price of photovoltaic power generation; c Grid is the grid-side electricity price; is the available power of wind power; is the available photovoltaic power; P Grid,t is the power purchased by the power grid during period t;

[0103] Specifically, during operation, a time period variable t is defined, t∈{1,…,T}. The microgrid energy storage is based on the output power of the converter. The efficiency of the converter will affect the operating cost, which can be based on the operating cost of the grid-type energy storage. Construct the objective function. On the other hand, the operating cost of synchronous generators is mostly composed of fuel prices, battery maintenance and replacement fees, pollutant emission penalties and pollution control fees. Therefore, based on the operating cost of synchronous generators at different output powers Construct the objective function. In addition, define the wind turbine power generation unit price, photovoltaic power generation unit price and grid-side electricity price as c WT , c PV and c Grid , through the wind power operation cost in the tth time period Photovoltaic operating costs and the cost of purchasing electricity from the power grid Construct the objective function.

[0104] The wind curtailment cost F in the tth time period t WT The formula for determining is:

[0105]

[0106] α WT P is the penalty cost coefficient for unit wind curtailment; WT,t is the actual wind power during period t;

[0107] The cost of abandoned light in the tth time period F t PV The formula for determining is:

[0108]

[0109] α PV P is the unit abandoned light penalty cost coefficient; PV,t is the actual photovoltaic power during period t.

[0110] Specifically, in order to increase the absorption capacity of new energy and reduce the wind and solar power abandonment rates, the solar power abandonment cost F in the tth time period is t PV and the abandoned light cost F in the tth time period t PV Construct the objective function.

[0111] S3. Based on the microgrid energy storage configuration and optimization scheduling model, multiple constraints are determined, wherein the multiple constraints include a first constraint based on the power balance of the power grid, a second constraint based on the available power of new energy, a third constraint based on the transmission power of the interconnection line, a fourth constraint based on the operating capacity of the synchronous generator, a fifth constraint based on the energy storage function, a sixth constraint based on the rotational kinetic energy of the grid-type energy storage support characteristics, and a seventh constraint based on the spare capacity.

[0112] The first constraints include:

[0113]

[0114] P Grid,t =P Load,t , is the load power during the period tt.

[0115] Specifically, to ensure the stable operation of the microgrid, the power of the energy storage system is balanced within any time period t.

[0116] The second constraint includes:

[0117]

[0118] Specifically, for wind power and photovoltaic power in the microgrid, the output power of wind power and photovoltaic power cannot be greater than the available power of wind power and photovoltaic power in each time period.

[0119] The third constraint includes:

[0120]

[0121] in, It is the maximum value of the transmission power of the tie line between the microgrid and the upper grid.

[0122] Specifically, if the tie line works in single-feed mode, that is, the microgrid can only purchase electricity from the upper grid, the third constraint can be obtained.

[0123] The fourth constraint condition includes:

[0124]

[0125] is the lower limit of the output power of the synchronous generator; is the upper limit of the output power of the synchronous generator; P Gen,t-1 is the actual output power of the generator during period t-1; is the maximum climbing power of the generator.

[0126] Specifically, in each time period t, the output power of the synchronous generator must meet the fourth constraint condition, that is, be between the lower limit and the upper limit of the output power of the synchronous generator. In addition, the climbing power of the synchronous generator is less than the maximum climbing power of the synchronous generator.

[0127] The fifth constraint includes:

[0128]

[0129] Among them, E n,t is the energy storage capacity at time t; E n,t-1 is the energy storage capacity at time t-1; is the charging power; is the discharge power; Indicates the charging operation status of the grid-connected energy storage at time t; Represents the discharge operation state of the grid-type energy storage at time t; η d is the discharge efficiency of the energy storage system; η c The charging efficiency of the energy storage system; is the lower limit of the energy storage capacity of the energy storage system; The upper limit of the energy storage capacity of the energy storage system; It is the upper limit of energy storage charging and discharging power.

[0130] Specifically, for grid-type energy storage, P Gfm,t Divided into charging power and discharge power Considering that energy storage devices cannot be charged and discharged at the same time, represents the charging operation state of the grid-connected energy storage at time t and Indicates that the sum of the discharge operation states of the grid-type energy storage at time t is less than or equal to 1; in order to prevent the energy storage unit from being overcharged or over-discharged, the energy storage capacity E n,t Need to meet

[0131] The sixth constraint condition includes:

[0132]

[0133]

[0134] Among them, R oCoF is the frequency change rate; ΔP loss is the power shortage; is the maximum frequency change rate; f0 is the rated frequency; E sys is the rotational kinetic energy of the energy storage system; H Gen is the inertia time constant of the synchronous generator; is the rated power; is the inertia time constant of the grid-type energy storage in the tth time period; It is the rated power of grid-type energy storage; is the rotational kinetic energy stored in the microgrid during the tth time period; H min is the lower limit of the energy storage inertia time constant; H max is the upper limit of the energy storage inertia time constant; P Gfm,t Transmit power to the energy storage interconnection line, is the maximum transmission power of the energy storage interconnection line.

[0135] Specifically, in order to avoid triggering the relay protection device under active disturbance, which may cause serious system failure, the maximum frequency change rate can be set. The overall inertia demand of the microgrid system is constrained. According to the characteristics that the wind power unit and the photovoltaic unit are connected to the microgrid using the grid-following control strategy and have small inertia, the inertia of the microgrid is mainly provided by the synchronous generator and the grid-connected energy storage. The inertia time constant of the synchronous generator is defined as H Gen , the rated power is defined as Then the rotational kinetic energy stored in the microgrid during the tth time period is

[0136] The essence of releasing the inertia support capacity of the grid-type energy storage is the power response capability of the energy storage. When the inertia time constant of the energy storage is 4s to 12s, considering that in the actual operation of the system, the transmission power of the interconnection line is relatively large during the peak load period, and the power shortage caused by the disconnection of the interconnection line has a greater impact on the frequency stability of the system, the inertia time constant of the energy storage is set to be proportional to the interconnection line power. When the inertia time constant is large, the energy released by the energy storage is large, and the frequency change rate decreases, which is conducive to maintaining the power balance of the system. When the inertia time constant is small, the energy released by the energy storage is small, and the frequency change rate is large, which may cause frequency stability problems in the system. Therefore, the constraints are obtained:

[0137]

[0138] The seventh constraint condition includes:

[0139]

[0140] is the total reserve capacity of the microgrid; is the reserve capacity of the synchronous generator in time period t; For the backup demand of energy storage system.

[0141] Specifically, in addition, considering the active disturbance accident, the active reserve capacity level of the microgrid is the key to suppressing the frequency variation amplitude. Combined with the above analysis of the microgrid composition structure, it can be seen that in the tth time period, the total reserve capacity of the microgrid is It is mainly provided by synchronous generators and grid-connected energy storage, which can be specifically expressed as:

[0142]

[0143] Considering the random failure of microgrid components, the prediction error of renewable energy and load fluctuation, in order to ensure the adequacy of frequency regulation reserve capacity, it is assumed that the prediction error of system net load (load minus renewable energy output) obeys normal distribution, and the standard deviation method is used to define ξ load is the reliability coefficient, then the equivalent load error standard deviation σ net_load ξ load times the system's backup requirements The constraints based on the total backup demand of the microgrid can be obtained:

[0144]

[0145] S4. According to the actual parameters of the microgrid, the objective function and multiple constraints are solved to obtain the optimal configuration and scheduling results of the microgrid.

[0146] Specifically, the actual parameters include: peak electricity price, valley electricity price, grid-connected electricity price for wind power and photovoltaic power, penalty cost coefficient for wind and solar power abandonment, upper limit of electricity purchase from the grid, unit cost of power capacity of energy storage, unit cost of energy capacity, benchmark discount rate, operating life, initial state of charge, upper and lower limits of SOC, charging and discharging efficiency, overload capacity of grid-connected energy storage, operating cost coefficient, rated power of synchronous generator, climbing power, operating cost coefficient, inertia time constant, backup demand of energy storage system, frequency and maximum frequency change rate of the system.

[0147] In one example, the photovoltaic output power, wind power output power, energy storage rated capacity, energy storage rated power, energy storage charging power, energy storage discharging power, synchronous generator output power and grid interaction power in each time period of the day are set as decision variables. Combined with the above objective function, based on the first constraint condition constrained by the power balance of the grid, the second constraint condition constrained by the available power of new energy, the third constraint condition constrained by the transmission power of the interconnection line, the fourth constraint condition constrained by the operating capacity of the synchronous generator, the fifth constraint condition constrained by the energy storage function, the sixth constraint condition constrained by the rotational kinetic energy of the grid-type energy storage support characteristics, and the seventh constraint condition constrained by the spare capacity, an optimal configuration model of the microgrid can be formed.

[0148] In another example, the actual parameters of location A are obtained, including: the peak electricity price is 0.55 yuan / kwh, the off-peak electricity price is 0.35 yuan / kwh, and the grid-connected electricity price of wind power and photovoltaic power is 0.33735 yuan / kwh. The penalty cost coefficient for wind and photovoltaic abandonment is 0.08. The upper limit of electricity purchase from the grid is 280kW. The unit cost of the power capacity of energy storage is K P The unit cost of energy capacity is 250 yuan / kW. E The initial state of charge is 0.8, the lower limit of SOC is 0.1, the upper limit of SOC is 0.9, and the charging and discharging efficiency is 0.95. The overload capacity k of grid-type energy storage g is 1.5, and its operating cost coefficient is 0.02($ / (kW 2 ·h)), 0.14 ($ / (kW·h)) and 0.05 ($ / h). The rated power of the synchronous generator is 100kW, the ramp power is 20kW, and the operating cost coefficients are 0.105 ($ / (kW 2 ·h)), 0.56 ($ / (kW·h)) and 0.01 ($ / h), the inertia time constant is 7s. Consider For 100kW, ΔP loss is 70kW, f0 is 50Hz, and the maximum frequency change rate of the system is 1Hz / s.

[0149] According to the actual parameters of location A, the objective function and multiple constraints are solved to obtain the optimal configuration and scheduling results of the microgrid. The optimal configuration and scheduling results include: the maximum rated power of the configured energy storage is 263kW, accounting for about 23.9% of the total installed capacity of new energy, and the maximum rated capacity of the energy storage to be configured is 394kWh.

[0150] From the above S1-S4, it can be seen that the method provided by the present invention introduces the energy storage rated power and rated capacity as decision variables into the objective function, and forms multiple constraints based on the reserve inertia and energy storage power of the grid-forming energy storage. The proposed microgrid energy storage configuration and day-ahead optimization scheduling strategy taking into account the energy storage networking capability can determine the optimization configuration and scheduling results according to the actual grid scenario, and then obtain the scheduling strategy corresponding to different time periods. While reducing the energy storage investment and construction costs, reducing the microgrid operating costs, and improving the utilization rate of new energy, it can ensure that the system has sufficient inertia level and frequency regulation capabilities under disturbance conditions to meet the user's usage needs in different usage scenarios.

[0151] The above mainly introduces the scheme of the embodiment of the present invention from the perspective of the method. It can be understood that in order to realize the above functions, the configuration system 100 includes at least one of the hardware structure and software modules corresponding to the execution of each function. It should be easily appreciated by those skilled in the art that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the embodiment of the present invention can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the embodiment of the present invention.

[0152] The embodiment of the present invention can divide the configuration system 100 into functional units according to the above method example. For example, the configuration system 100 can be divided into functional units corresponding to various functions, or two or more functions can be integrated into one processing unit. The above integrated unit can be implemented in the form of hardware or in the form of software functional units. It should be noted that the division of units in the embodiment of the present invention is schematic and is only a logical functional division. There may be other division methods in actual implementation.

[0153] For example, Figure 3 The figure is a schematic diagram of the hardware structure of a configuration system according to an embodiment of the present invention. The configuration system 100 includes: a model building module 110, which is used to establish a microgrid energy storage configuration and optimization scheduling model with the energy storage networking capability of the microgrid as an evaluation standard; a function building module 120, which is used to establish an objective function with the overall operation benefit of the microgrid as the goal, and the optimal operation benefit includes maximizing the utilization rate of new energy, minimizing the energy storage investment cost and minimizing the power generation cost; a condition determination module 130, which is used to determine multiple constraints based on the microgrid energy storage configuration and optimization scheduling model, wherein the multiple constraints include a first constraint condition with grid power balance as a constraint, a second constraint condition with new energy available power as a constraint, a third constraint condition with interconnection line transmission power as a constraint, a fourth constraint condition with synchronous generator operation capability as a constraint, a fifth constraint condition with energy storage function as a constraint, a sixth constraint condition with rotational kinetic energy of the networking type energy storage support characteristics as a constraint, and a seventh constraint condition with spare capacity as a constraint; a result determination module 140, which is used to solve the objective function and the multiple constraints according to the actual parameters of the microgrid to obtain the optimization configuration and scheduling results of the microgrid.

[0154] Among them, the objective function is:

[0155]

[0156] Among them, C In is the annual value of the initial investment cost; The operating costs of grid-type energy storage; is the operating cost of synchronous generator at different output powers; is the wind power operation cost in the tth time period, is the photovoltaic operation cost in the tth time period; is the power purchase cost of the power grid in the tth time period; F t WT F is the cost of wind curtailment; t PV The cost of abandoned light.

[0157] It should be understood that the specific description of the above optional manners can refer to the above method embodiments, which will not be repeated here. In addition, the explanation of any configuration system 100 provided above and the description of the beneficial effects can refer to the above corresponding method embodiments, which will not be repeated here.

[0158] The embodiment of the present invention further provides a computer-readable storage medium, in which at least one computer instruction is stored, and the at least one computer instruction is loaded and executed by a processor to implement the methods of the above embodiments. For the explanation of the relevant contents and the description of the beneficial effects in any of the above-mentioned computer-readable storage media, reference can be made to the above-mentioned corresponding embodiments, which will not be repeated here.

[0159] The embodiment of the present invention further provides a chip. The chip integrates a control circuit and one or more ports for implementing the functions of the above configuration system 100. Optionally, the functions supported by the chip can be referred to above and will not be described in detail here.

[0160] Those skilled in the art will appreciate that all or part of the steps of the above embodiments can be implemented by instructing the relevant hardware through a program, and the program can be stored in a computer-readable storage medium. The above-mentioned storage medium can be a read-only memory, a random access memory, etc. The above-mentioned processing unit or processor can be a central processing unit, a general-purpose processor, a specific circuit structure (application specific integrated circuit, ASIC), a microprocessor (digital signal processor, DSP), a field programmable gate array (field prograllable gatearray, FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof.

[0161] The embodiment of the present invention also provides a computer program product including instructions, when the instructions are run on a computer, the computer executes any one of the methods in the above embodiments. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the process or function according to the embodiment of the present invention is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., an SSD), etc.

[0162] It should be noted that the above-mentioned devices for storing computer instructions or computer programs provided in the embodiments of the present invention, such as but not limited to the above-mentioned memory, computer-readable storage medium and communication chip, etc., all have non-transitory. Those skilled in the art should be aware that in one or more of the above-mentioned examples, the functions described in the embodiments of the present invention can be implemented with hardware, software, firmware or any combination thereof. When implemented using software, these functions can be stored in a computer-readable storage medium or transmitted as one or more instructions or codes on a computer-readable storage medium. Computer-readable storage media include computer storage media and communication media, wherein the communication medium includes any medium that is convenient for transmitting a computer program from one place to another. The storage medium can be any available medium that a general or special-purpose computer can access.

[0163] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for optimizing energy storage configuration in a microgrid, characterized in that: The method comprises: Establish a microgrid energy storage configuration and optimization scheduling model based on the microgrid energy storage networking capability as the evaluation standard; Establishing an objective function with the goal of optimizing the overall operation benefit of the microgrid, wherein the optimal operation benefit includes maximizing the utilization rate of new energy, minimizing the investment cost of energy storage, and minimizing the cost of power generation; Based on the microgrid energy storage configuration and optimization scheduling model, multiple constraints are determined, wherein the multiple constraints include a first constraint condition based on grid power balance, a second constraint condition based on available power of new energy, a third constraint condition based on transmission power of interconnection lines, a fourth constraint condition based on operating capacity of synchronous generators, a fifth constraint condition based on energy storage function, a sixth constraint condition based on rotational kinetic energy of grid-type energy storage support characteristics, and a seventh constraint condition based on spare capacity; Solving the objective function and the plurality of constraints according to actual parameters of the microgrid to obtain an optimal configuration and scheduling result of the microgrid; Wherein, the objective function is: Among them, C In is the annual value of the initial investment cost; The operating costs of grid-type energy storage; is the operating cost of synchronous generator at different output powers; is the wind power operation cost in the tth time period, is the photovoltaic operation cost in the tth time period; is the power purchase cost of the power grid in the tth time period; F t WT F is the cost of wind curtailment; t PV The cost of abandoned light.

2. The method according to claim 1, characterized in that Annual value of initial investment cost C In The formula for determining is: Among them, K P , K E are the unit costs of energy storage power capacity and energy capacity respectively; r is the base discount rate; n e is the operating life of the energy storage system; P e E is the energy storage rated power; e is the rated capacity of energy storage; Operating costs of grid-connected energy storage The formula for determining is: Operating costs of synchronous generators at different output powers The formula for determining is: Among them, α Gfm , β Gfm and γ Gfm are the operating parameters of grid-type energy storage; α Gen , β Gen and γ Gen are the operating parameters of the synchronous generator respectively; P Gfm,t is the actual interaction power of the grid-type energy storage during period t; P Gen,t is the actual output power of the generator during period t; Wind power operation cost in time period t The formula for determining is: PV operation cost in time period t The formula for determining is: The cost of purchasing electricity from the power grid during the tth time period The formula for determining is: c WT is the unit price of wind turbine power generation; c PV is the unit price of photovoltaic power generation; c Grid is the grid-side electricity price; is the available power of wind power; is the available photovoltaic power; P Grid,t is the power purchased by the power grid during period t; The wind curtailment cost F in the tth time period t WT The formula for determining is: α WT P is the unit wind curtailment penalty cost coefficient; WT,t is the actual wind power during period t; The cost of abandoned light in the tth time period F t PV The formula for determining is: α PV P is the unit abandoned light penalty cost coefficient; PV,t is the actual photovoltaic power during period t.

3. The method according to claim 2, characterized in that The first constraints include: P Load,t , is the load power during the period tt.

4. The method according to claim 3, characterized in that The second constraint includes:

5. The method according to claim 4, characterized in that The third constraint includes: in, It is the maximum value of the transmission power of the tie line between the microgrid and the upper grid.

6. The method according to claim 5, characterized in that The fourth constraint condition includes: is the lower limit of the output power of the synchronous generator; is the upper limit of the output power of the synchronous generator; P Gen,t-1 is the actual output power of the generator during period t-1; is the maximum climbing power of the generator.

7. The method according to claim 6, characterized in that The fifth constraint includes: Among them, E n,t is the energy storage capacity at time t; E n,t-1 is the energy storage capacity at time t-1; is the charging power; is the discharge power; Indicates the charging operation status of the grid-connected energy storage at time t; Represents the discharge operation state of the grid-type energy storage at time t; η d is the discharge efficiency of the energy storage system; η c The charging efficiency of the energy storage system; is the lower limit of the energy storage capacity of the energy storage system; The upper limit of the energy storage capacity of the energy storage system; It is the upper limit of energy storage charging and discharging power.

8. The method according to claim 7, characterized in that The sixth constraint condition includes: Among them, R oCoF is the frequency change rate; ΔP loss is the power shortage; is the maximum frequency change rate; f0 is the rated frequency; E sys is the rotational kinetic energy of the energy storage system; H Gen is the inertia time constant of the synchronous generator; is the rated power; is the inertia time constant of the grid-type energy storage in the tth time period; It is the rated power of grid-type energy storage; is the rotational kinetic energy stored in the microgrid during the tth time period; H min is the lower limit of the energy storage inertia time constant; H max is the upper limit of the energy storage inertia time constant; P Gfm,t Transmit power to the energy storage interconnection line, is the maximum transmission power of the energy storage interconnection line.

9. The method according to claim 8, characterized in that The seventh constraint condition includes: is the total reserve capacity of the microgrid; is the reserve capacity of the synchronous generator in time period t; For the backup demand of energy storage system.

10. A microgrid energy storage optimization configuration system, characterized in that: The system comprises: Model building module, used to establish a microgrid energy storage configuration and optimization scheduling model based on the microgrid's energy storage networking capability as the evaluation standard; A function establishment module is used to establish an objective function with the overall operation benefit of the microgrid as the goal, wherein the operation benefit optimization includes maximizing the utilization rate of new energy, minimizing the energy storage investment cost and minimizing the power generation cost; A condition determination module, for determining a plurality of constraint conditions based on the microgrid energy storage configuration and the optimization scheduling model, wherein the plurality of constraint conditions include a first constraint condition based on the power balance of the power grid, a second constraint condition based on the available power of the new energy, a third constraint condition based on the transmission power of the tie line, a fourth constraint condition based on the operating capacity of the synchronous generator, a fifth constraint condition based on the energy storage function, a sixth constraint condition based on the rotational kinetic energy of the grid-forming energy storage support characteristics, and a seventh constraint condition based on the spare capacity; A result determination module, used to solve the objective function and the plurality of constraint conditions according to actual parameters of the microgrid to obtain an optimal configuration and scheduling result of the microgrid; Wherein, the objective function is: Among them, C In is the annual value of the initial investment cost; The operating costs of grid-type energy storage; is the operating cost of synchronous generator at different output powers; is the wind power operation cost in the tth time period, is the photovoltaic operation cost in the tth time period; is the power purchase cost of the power grid in the tth time period; F t WT F is the cost of wind curtailment; t PV The cost of abandoned light.

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