Gravity-electrochemistry hybrid energy storage power evaluation method and device

Abstract

The invention discloses a power evaluation method and device for gravity-electrochemistry hybrid energy storage. The method comprises the following steps: acquiring the operation number of energy storage units corresponding to gravity energy storage and the number of weight blocks which can be input; determining a power adjustment pre-estimation range of the gravity energy storage based on the commissioning quantity and the quantity of the weight blocks which can be commissioned; based on the performance parameters and historical power data of the electrochemical energy storage, determining a power adjustment estimation range of the electrochemical energy storage; and based on the topological structure of the gravity-electrochemical hybrid energy storage, combining the power adjustment estimation range of the gravity energy storage and the electrochemical energy storage, and determining the power evaluation of the gravity-electrochemical hybrid energy storage in the charge-discharge state. And the power of the gravity-electrochemical hybrid energy storage can be accurately evaluated.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric energy storage configuration, and in particular relates to a power evaluation method and device for gravity-electrochemical hybrid energy storage. Background Art

[0002] The large-scale centralized grid connection of renewable energy sources such as wind and solar energy has brought significant challenges to the safe and stable operation of the power system. The power generation output of these energy sources is random, intermittent and volatile, making the power supply difficult to predict and prone to violent fluctuations, which in turn affects the frequency stability and power balance of the power grid. In order to effectively meet these challenges, it has become particularly urgent to build a new power system. In this process, the integration and application of energy storage technology is seen as the key to improving the system's regulation capabilities and enhancing the flexibility and reliability of the power grid.

[0003] The widespread application of energy storage systems can improve the flexibility, economy and safety of power grids. Gravity energy storage systems stand out for their high safety, environmental protection, flexible site selection and low overall cost. The existing vertical matrix gravity energy storage system efficiently converts gravitational potential energy into electrical energy through the vertical lifting and lowering movement of heavy blocks, thereby realizing energy storage and release. However, the mechanical structure characteristics of the gravity energy storage system determine that its output power has a fixed climbing rate, which means that the speed of change of the system output power is limited by the physical process and cannot quickly respond to the rapid power fluctuation requirements of the power grid. Therefore, the use of gravity energy storage alone may not meet the high requirements of the power grid for real-time regulation capabilities and dynamic response speed.

[0004] In order to better meet the power demand of the power grid, when constructing a hybrid energy storage system that includes gravity energy storage and electrochemical energy storage in parallel, accurate evaluation of its adjustable power becomes the core basis for formulating the power system dispatch strategy. Therefore, how to provide an adjustable power evaluation method and system for "gravity-electrochemical" hybrid energy storage to achieve the adjustable power evaluation of the hybrid energy storage system composed of gravity energy storage and electrochemical energy storage is an urgent problem to be solved by technicians in this field. Summary of the invention

[0005] In view of the defects existing in the above-mentioned prior art, the present invention provides a power evaluation method and device for gravity-electrochemical hybrid energy storage, which can accurately evaluate the power of gravity-electrochemical hybrid energy storage.

[0006] In a first aspect, the present invention provides a power evaluation method for gravity-electrochemical hybrid energy storage, comprising:

[0007] Obtain the number of energy storage units in operation and the number of heavy blocks that can be put into operation for gravity energy storage;

[0008] Determine the estimated range of power adjustment for gravity energy storage based on the number of units put into operation and the number of weight blocks that can be put into operation;

[0009] Determine the estimated power adjustment range of electrochemical energy storage based on performance parameters and historical power data of electrochemical energy storage;

[0010] Based on the topological structure of gravity-electrochemical hybrid energy storage and combining the power adjustment estimation range of gravity energy storage and electrochemical energy storage, the power evaluation of gravity-electrochemical hybrid energy storage under charging and discharging state is determined.

[0011] Furthermore, based on the number of units put into operation and the number of weight blocks that can be put into operation, the power adjustment estimation range of the gravity energy storage is determined, including:

[0012] Based on the number of energy storage units in operation, combined with the power change corresponding to a single weight block in the energy storage unit and the time interval required for switching adjacent weight blocks, the estimated adjustment power of the gravity energy storage within the evaluation period is determined;

[0013] Based on the number of weight blocks that can be put in, combined with the power change corresponding to a single weight block in the energy storage unit and the estimated adjustment power of the gravity energy storage during the evaluation period, the estimated power adjustment range of the gravity energy storage for exchanging power is determined.

[0014] Furthermore, the estimated adjustment power of the gravity energy storage during the evaluation period satisfies the following relationship:

[0015]

[0016] Where, d gra is the estimated adjusted power of gravity energy storage during the evaluation period, n is the number of gravity energy storage units put into operation, P single is the power change corresponding to a single weight block, Δt is the evaluation period, ΔT gra The time interval required for switching between adjacent weight blocks.

[0017] Further, the power adjustment estimated range of the gravity energy storage for exchanging power includes the power adjustment estimated range of the gravity energy storage for output power and the power adjustment estimated range of the gravity energy storage for absorbing power;

[0018] The estimated range of power adjustment for output power of gravity energy storage satisfies the following relationship:

[0019]

[0020]

[0021] In the formula, and They are the maximum power and minimum power that the gravity energy storage estimates to be output to the grid at time t, is the number of weight blocks put into the nth unit when the gravity energy storage outputs power, d gra is the estimated adjustment power of gravity energy storage during the evaluation period, n is the number of gravity energy storage units put into operation, P single is the power change corresponding to a single weight block;

[0022] The estimated range of power adjustment for gravity energy storage to absorb power satisfies the following relationship:

[0023]

[0024]

[0025] In the formula, and They are the maximum power and minimum power that gravity energy storage estimates to be absorbed from the grid at time t, The number of weight blocks put into the nth unit when absorbing power through gravity energy storage.

[0026] Furthermore, based on the performance parameters and historical power data of the electrochemical energy storage, an estimated range of power adjustment of the electrochemical energy storage is determined, including: based on the state of charge, power capacity and historical output power of the electrochemical energy storage, an estimated range of power adjustment for the output power of the electrochemical energy storage is determined; and based on the state of charge, power capacity and historical absorption power of the electrochemical energy storage, an estimated range of power adjustment for the absorption power of the electrochemical energy storage is determined.

[0027] Furthermore, the power adjustment estimation range of the output power of the electrochemical energy storage satisfies the following relationship:

[0028]

[0029]

[0030] In the formula, and are the maximum power and minimum power that the electrochemical energy storage is estimated to output to the grid at time t, P Bess,d (t-1) is the power output of the electrochemical energy storage to the grid at time t-1, SOC(t) is the state of charge of the electrochemical energy storage at time t, SOC min is the minimum state of charge of electrochemical energy storage, Δt is the evaluation period, η d is the discharge efficiency of electrochemical energy storage, E rate is the power capacity of electrochemical energy storage;

[0031] The estimated range of power adjustment for electrochemical energy storage to absorb power satisfies the following relationship:

[0032]

[0033]

[0034] In the formula, and are the maximum power and minimum power that electrochemical energy storage can absorb from the grid at time t, P Bess,c (t-1) is the power absorbed by the electrochemical energy storage from the grid at time t-1, SOC max is the maximum state of charge of electrochemical energy storage, η c is the charging efficiency of electrochemical energy storage.

[0035] Furthermore, the topological structure of gravity-electrochemical hybrid energy storage satisfies the following relationship:

[0036] 0≤ω gra,c +ω gra,d ≤1

[0037] 0≤ω Bess,c +ω Bess,d ≤1

[0038] ω gra,c ·ω Bess,d +ω gra,d ·ω Bess,c =0

[0039] ω gra,c ,ω gra,d ∈{0,1}

[0040] ω Bess,c ,ω Bess,d ∈{0,1}

[0041] In the formula, ω gra,c Represents the absorption power state of gravity energy storage, when ω gra,c =1, the gravity energy storage is in the state of absorbing power. gra,c =0, the gravity energy storage is in an idle state; ω gra,d Represents the output power state of gravity energy storage, when ω gra,d =1, the gravity energy storage is in the output power state, when ω gra,d =0, the gravity energy storage is in an idle state; ω Bess,c Represents the absorption power state of electrochemical energy storage. When ω Bess,c =1, the electrochemical energy storage is in the state of absorbing power. Bess,c =0, the electrochemical energy storage is in an idle state; ω Bess,d Represents the output power state of electrochemical energy storage. When ω Bess,d =1, the electrochemical energy storage is in the output power state. Bess,d=0, the electrochemical energy storage is in idle state.

[0042] Furthermore, based on the topological structure of gravity-electrochemical hybrid energy storage and combined with the power adjustment estimation range of gravity energy storage and electrochemical energy storage, the power evaluation of gravity-electrochemical hybrid energy storage under charging and discharging state is determined, including:

[0043] Based on the output power state characterization of the gravity-electrochemical hybrid energy storage and the estimated power adjustment range of the output power, the power evaluation of the gravity-electrochemical hybrid energy storage in the discharge state is determined; based on the absorption power state characterization of the gravity-electrochemical hybrid energy storage and the estimated power adjustment range of the absorption power, the power evaluation of the gravity-electrochemical hybrid energy storage in the charging state is determined.

[0044] Furthermore, the power evaluation of gravity-electrochemical hybrid energy storage in the discharge state satisfies the following relationship:

[0045]

[0046]

[0047] In the formula, Estimate the maximum power output to the grid at time t for gravity-electrochemical hybrid energy storage, Estimate the minimum power output to the grid at time t for gravity-electrochemical hybrid energy storage;

[0048] The power evaluation of gravity-electrochemical hybrid energy storage in the charging state satisfies the following relationship:

[0049]

[0050]

[0051] In the formula, Estimate the maximum power absorbed from the grid at time t for gravity-electrochemical hybrid energy storage, Estimate the minimum power absorbed from the grid at time t for gravity-electrochemical hybrid energy storage.

[0052] In a second aspect, the present invention further provides a power evaluation device for gravity-electrochemical hybrid energy storage, using the power evaluation method for gravity-electrochemical hybrid energy storage, the power evaluation device comprises:

[0053] A gravity energy storage configuration module, which is used to obtain the number of energy storage units corresponding to the gravity energy storage and the number of weight blocks that can be put into operation;

[0054] A gravity energy storage power estimation module, which is used to determine the power adjustment estimation range of the gravity energy storage based on the number of units put into operation and the number of weight blocks that can be put into operation;

[0055] The electrochemical energy storage power estimation module is used to determine the power adjustment estimation range of the electrochemical energy storage based on the performance parameters and historical power data of the electrochemical energy storage.

[0056] The hybrid energy storage power evaluation module is used to determine the power evaluation of the gravity-electrochemical hybrid energy storage under the charging and discharging state based on the topological structure of the gravity-electrochemical hybrid energy storage and combining the power adjustment estimation range of the gravity energy storage and the electrochemical energy storage.

[0057] Furthermore, the gravity energy storage power estimation module includes:

[0058] Based on the number of energy storage units in operation, combined with the power change corresponding to a single weight block in the energy storage unit and the time interval required for switching adjacent weight blocks, the estimated adjustment power of the gravity energy storage within the evaluation period is determined;

[0059] Based on the number of weight blocks that can be put in, combined with the power change corresponding to a single weight block in the energy storage unit and the estimated adjustment power of the gravity energy storage during the evaluation period, the estimated power adjustment range of the gravity energy storage for exchanging power is determined.

[0060] Furthermore, the electrochemical energy storage power estimation module includes: determining the power adjustment estimation range of the electrochemical energy storage for output power based on the charge state, power capacity and historical output power of the electrochemical energy storage; and determining the power adjustment estimation range of the electrochemical energy storage for absorption power based on the charge state, power capacity and historical absorption power of the electrochemical energy storage.

[0061] Furthermore, the hybrid energy storage power evaluation module includes:

[0062] Based on the output power state characterization of the gravity-electrochemical hybrid energy storage and the estimated power adjustment range of the output power, the power evaluation of the gravity-electrochemical hybrid energy storage in the discharge state is determined; based on the absorption power state characterization of the gravity-electrochemical hybrid energy storage and the estimated power adjustment range of the absorption power, the power evaluation of the gravity-electrochemical hybrid energy storage in the charging state is determined.

[0063] The present invention provides a power evaluation method and device for gravity-electrochemical hybrid energy storage, which at least have the following beneficial effects:

[0064] (1) By accurately evaluating the power output capabilities of gravity energy storage and electrochemical energy storage, the collaborative work of the two energy storage methods can be optimized and unnecessary energy losses can be avoided, thereby improving the overall efficiency of the entire gravity-electrochemical hybrid energy storage system.

[0065] (2) By accurately evaluating the power of the hybrid energy storage system, the capacity and configuration of the energy storage equipment can be planned more reasonably, avoiding over-investment or idle resources, thereby maximizing cost-effectiveness while meeting energy storage needs and reducing the full life cycle cost of the energy storage system.

[0066] (3) The gravity-electrochemical hybrid energy storage system can more effectively balance the instability and intermittency of renewable energy generation. Through precise power assessment, it can ensure that the gravity-electrochemical hybrid energy storage system stores excess electricity during peak renewable energy generation and releases electricity during low periods, thereby promoting large-scale access and efficient consumption of renewable energy and promoting the green transformation of the energy structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 A flow chart of a power evaluation method for gravity-electrochemical hybrid energy storage provided by the present invention;

[0068] Figure 2 A flow chart for determining a power adjustment estimation range of gravity energy storage provided by an embodiment of the present invention;

[0069] Figure 3 A schematic diagram of the charge and discharge capability of electrochemical energy storage provided by an embodiment of the present invention;

[0070] Figure 4 A schematic diagram of adjustable power evaluation of "gravity-electrochemical" hybrid energy storage provided by an embodiment of the present invention;

[0071] Figure 5 A schematic diagram of a power evaluation device for gravity-electrochemical hybrid energy storage provided by the present invention. DETAILED DESCRIPTION

[0072] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0073] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0074] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0075] Due to its own mechanical structure limitation, the output power characteristics of gravity energy storage present a step output characteristic. Gravity energy storage has a fixed interval time for the input of heavy blocks. A single gravity energy storage device is difficult to meet the real-time power demand of the grid side. However, the power of electrochemical energy storage can achieve smooth and continuous output. The hybrid energy storage system composed of the two can provide inertia for the grid through the topology of gravity energy storage directly connected to the grid, and can also meet the power demand of the grid side through the coordinated control of gravity energy storage and electrochemical energy storage. However, the power evaluation of the hybrid energy storage system composed of the two is currently not possible.

[0076] like Figure 1 As shown, the present invention provides a power evaluation method for gravity-electrochemical hybrid energy storage, which may include:

[0077] Obtain the number of energy storage units in operation and the number of heavy blocks that can be put into operation for gravity energy storage;

[0078] Determine the estimated range of power adjustment for gravity energy storage based on the number of units put into operation and the number of weight blocks that can be put into operation;

[0079] Determine the estimated power adjustment range of electrochemical energy storage based on performance parameters and historical power data of electrochemical energy storage;

[0080] Based on the topological structure of gravity-electrochemical hybrid energy storage and combining the power adjustment estimation range of gravity energy storage and electrochemical energy storage, the power evaluation of gravity-electrochemical hybrid energy storage under charging and discharging state is determined.

[0081] Taking into account the step and discrete characteristics of the output power of gravity energy storage, a mathematical model of gravity energy storage is constructed to determine the number of gravity energy storage units put into operation and the number of weight blocks put into operation for each gravity energy storage unit.

[0082] Vertical matrix gravity energy storage adopts a topological structure that is directly connected to the power grid through a synchronous machine, which can provide inertia support for the power grid. The output power of the gravity energy storage presents step and discrete characteristics. The input torque of the gravity energy storage unit is changed by the rise or fall of the weight block, thereby realizing the adjustment of the output power of the gravity energy storage.

[0083] The vertical matrix gravity energy storage system uses a transmission device to drag the elevator car and lift or lower the weight through the elevator car. Its working principle is mainly to realize electromechanical energy conversion by driving the synchronous machine through discrete weight blocks. According to the above principle, the active control link of a single gravity energy storage unit is constructed, and the model is established as follows:

[0084]

[0085]

[0086]

[0087]

[0088] Where, T i is the input mechanical torque provided by the ith weight block to the synchronous machine, m is the unit weight block mass; g is the gravitational acceleration; v is the weight block speed, η is the efficiency of converting gravitational potential energy into electrical energy; S n is the rated capacity of the gravity energy storage unit, T m is the total torque of the gravity energy storage mechanical part; T m_gra is the input mechanical torque of the synchronous machine, T e is the electromagnetic torque of the synchronous machine; T j is the inertia time constant of the synchronous machine, D is the damping coefficient of the gravity energy storage unit, δ is the power angle of the synchronous machine; ω0 is the synchronous speed of the synchronous machine; ω is the electrical angular velocity of the synchronous machine.

[0089] Due to the physical characteristics of the mechanical part of the gravity energy storage unit, there is a fixed time interval between the input and output of each weight block, which directly affects the climbing rate of the gravity energy storage unit. The input interval time constraint of each weight block in the mechanical device of gravity energy storage is:

[0090] t on_i =t on_1 +(i-1)Δt

[0091] In the formula, i is the number of the weight block, t on_1 is the time for the first weight block to be put into operation, t on_i is the time it takes for the i-th weight block to be put into operation, and Δt is the interval time for the weight blocks to be put into operation in the gravity energy storage mechanical device.

[0092] According to the topological structure of the "gravity-electrochemical" hybrid energy storage system, the number of gravity energy storage units put into operation in the gravity energy storage array system is set to n, and the maximum number of weight blocks that can be put into each gravity energy storage unit is N. For the convenience of explanation, the number of gravity energy storage units put into operation is set to n, and they are recorded as gravity energy storage unit 1, gravity energy storage unit 2... gravity energy storage unit n. At this time, if the gravity energy storage releases electricity, the number of weight blocks put into each gravity energy storage unit is recorded as If the gravity energy storage absorbs electricity, the number of weight blocks put into each gravity energy storage unit is recorded as

[0093] like Figure 2 As shown, based on the number of units put into operation and the number of weight blocks that can be put into operation, the estimated power adjustment range of gravity energy storage is determined, including:

[0094] Based on the number of energy storage units in operation, combined with the power change corresponding to a single weight block in the energy storage unit and the time interval required for switching adjacent weight blocks, the estimated adjustment power of gravity energy storage within the evaluation period is determined to meet the following relationship:

[0095]

[0096] Where, d gra is the estimated adjusted power of gravity energy storage during the evaluation period, n is the number of gravity energy storage units put into operation, P single is the power change corresponding to a single weight block, Δt is the evaluation period, ΔT gra The time interval required to switch between adjacent weight blocks;

[0097] Based on the number of weight blocks that can be put in, combined with the power change corresponding to a single weight block in the energy storage unit and the estimated adjustment power of the gravity energy storage during the evaluation period, the estimated power adjustment range of the gravity energy storage for exchanging power is determined.

[0098] The estimated power adjustment range of gravity energy storage for exchange power, including the estimated power adjustment range of gravity energy storage for output power and the estimated power adjustment range of gravity energy storage for absorption power;

[0099] When the hybrid energy storage system (gravity-electrochemical hybrid energy storage) needs to adjust power, the power released by the gravity energy storage to the grid is set to be positive, and the power absorbed by the gravity energy storage from the grid is set to be negative;

[0100] When the gravity energy storage is running to generate power, the weight blocks in each gravity energy storage unit are in a falling state. At this time, the gravity energy storage array uses each gravity energy storage unit to simultaneously put in / out the number of weight blocks in the unit. At this time, the adjustable power of the gravity energy storage array reaches the maximum. The power adjustment estimated range of the output power of the gravity energy storage satisfies the following relationship:

[0101]

[0102]

[0103] In the formula, and They are the maximum power and minimum power that the gravity energy storage estimates to be output to the grid at time t, is the number of weight blocks put into the nth unit when the gravity energy storage outputs power, d gra is the estimated adjustment power of gravity energy storage during the evaluation period, n is the number of gravity energy storage units put into operation, P single is the power change corresponding to a single weight block;

[0104] When the gravity energy storage is operating in the absorption power, the weight blocks in each gravity energy storage unit are in an ascending operation state. At this time, the gravity energy storage array uses each gravity energy storage unit to simultaneously put in / out the number of weight blocks in the unit. At this time, the adjustable power of the gravity energy storage array reaches the maximum, and the power adjustment estimated range of the gravity energy storage for absorbing power satisfies the following relationship:

[0105]

[0106]

[0107] In the formula, and They are the maximum power and minimum power that gravity energy storage estimates to be absorbed from the grid at time t, The number of weight blocks put into the nth unit when absorbing power through gravity energy storage.

[0108] The power range of an electrochemical energy storage battery is not only related to its own power capacity, but also to its SOC state, such as Figure 3 Specifically, based on the performance parameters and historical power data of the electrochemical energy storage, the power adjustment estimated range of the electrochemical energy storage is determined, including: based on the state of charge, power capacity and historical output power of the electrochemical energy storage, the power adjustment estimated range of the output power of the electrochemical energy storage is determined; and based on the state of charge, power capacity and historical absorption power of the electrochemical energy storage, the power adjustment estimated range of the absorption power of the electrochemical energy storage is determined.

[0109] When the electrochemical energy storage is operating in the discharge state, at time t, the power adjustment estimated range of the electrochemical energy storage output power satisfies the following relationship:

[0110]

[0111]

[0112] In the formula, and are the maximum power and minimum power that the electrochemical energy storage is estimated to output to the grid at time t, P Bess,d (t-1) is the power output of the electrochemical energy storage to the grid at time t-1, SOC(t) is the state of charge of the electrochemical energy storage at time t, SOC min is the minimum state of charge of electrochemical energy storage, Δt is the evaluation period, η d is the discharge efficiency of electrochemical energy storage, E rate is the power capacity of electrochemical energy storage;

[0113] When the electrochemical energy storage is operating in the charging state, at time t, the estimated range of power adjustment of the electrochemical energy storage for absorbing power satisfies the following relationship:

[0114]

[0115]

[0116] In the formula, and are the maximum power and minimum power that electrochemical energy storage can absorb from the grid at time t, P Bess,c (t-1) is the power absorbed by the electrochemical energy storage from the grid at time t-1, SOC max is the maximum state of charge of electrochemical energy storage, η c is the charging efficiency of electrochemical energy storage.

[0117] According to the topological structure of "gravity-electrochemical" hybrid energy storage, when the grid dispatch instruction is issued, the operating state of gravity energy storage should be consistent with the operating state of electrochemical energy storage, that is, both are in the discharge state or charging state at the same time. Specifically, the topological structure of gravity-electrochemical hybrid energy storage satisfies the following relationship:

[0118] 0≤ω gra,c +ω gra,d ≤1

[0119] 0≤ω Bess,c +ω Bess,d ≤1

[0120] ω gra,c ·ω Bess,d +ωgra,d ·ω Bess,c =0

[0121] ω gra,c ,ω gra,d ∈{0,1}

[0122] ω Bess,c ,ω Bess,d ∈{0,1}

[0123] In the formula, ω gra,c Represents the absorption power state of gravity energy storage, when ω gra,c =1, the gravity energy storage is in the state of absorbing power. gra,c =0, the gravity energy storage is in an idle state; ω gra,d Represents the output power state of gravity energy storage, when ω gra,d =1, the gravity energy storage is in the output power state, when ω gra,d =0, the gravity energy storage is in an idle state; ω Bess,c Represents the absorption power state of electrochemical energy storage. When ω Bess,c =1, the electrochemical energy storage is in the state of absorbing power. Bess,c =0, the electrochemical energy storage is in an idle state; ω Bess,d Represents the output power state of electrochemical energy storage. When ω Bess,d =1, the electrochemical energy storage is in the output power state. Bess,d =0, the electrochemical energy storage is in idle state.

[0124] Based on the topological structure of gravity-electrochemical hybrid energy storage and combined with the power adjustment estimation range of gravity energy storage and electrochemical energy storage, the power evaluation of gravity-electrochemical hybrid energy storage under charging and discharging state is determined, including:

[0125] Based on the output power state characterization of the gravity-electrochemical hybrid energy storage and the estimated power adjustment range of the output power, the power evaluation of the gravity-electrochemical hybrid energy storage in the discharge state is determined; based on the absorption power state characterization of the gravity-electrochemical hybrid energy storage and the estimated power adjustment range of the absorption power, the power evaluation of the gravity-electrochemical hybrid energy storage in the charging state is determined.

[0126] like Figure 4 As shown in FIG. 1 , when the “gravity-electrochemical” hybrid energy storage is operated in the discharge state, the power evaluation of the gravity-electrochemical hybrid energy storage in the discharge state satisfies the following relationship:

[0127]

[0128]

[0129] In the formula, Estimate the maximum power output to the grid at time t for gravity-electrochemical hybrid energy storage, Estimate the minimum power output to the grid at time t for gravity-electrochemical hybrid energy storage;

[0130] When the "gravity-electrochemical" hybrid energy storage operates in the charging state, the power evaluation of the gravity-electrochemical hybrid energy storage in the charging state satisfies the following relationship:

[0131]

[0132]

[0133] In the formula, Estimate the maximum power absorbed from the grid at time t for gravity-electrochemical hybrid energy storage, Estimate the minimum power absorbed from the grid at time t for gravity-electrochemical hybrid energy storage.

[0134] The present invention can optimize the collaborative work of the two energy storage methods by accurately evaluating the power output capacity of gravity energy storage and electrochemical energy storage, avoid unnecessary energy loss, and thus improve the overall efficiency of the entire gravity-electrochemical hybrid energy storage system. By accurately evaluating the power of the hybrid energy storage system, the capacity and configuration of the energy storage equipment can be more reasonably planned to avoid over-investment or idle resources, thereby maximizing cost-effectiveness and reducing the full life cycle cost of the energy storage system while meeting energy storage needs. The gravity-electrochemical hybrid energy storage system can more effectively balance the instability and intermittency of renewable energy generation. Through accurate power evaluation, it can ensure that the gravity-electrochemical hybrid energy storage system stores excess electricity during peak renewable energy generation and releases electricity during low periods, thereby promoting large-scale access and efficient consumption of renewable energy and promoting the green transformation of the energy structure.

[0135] like Figure 5 As shown, the present invention also provides a power evaluation device for gravity-electrochemical hybrid energy storage, using the power evaluation method of gravity-electrochemical hybrid energy storage, the power evaluation device comprises:

[0136] A gravity energy storage configuration module, which is used to obtain the number of energy storage units corresponding to the gravity energy storage and the number of weight blocks that can be put into operation;

[0137] A gravity energy storage power estimation module, which is used to determine the power adjustment estimation range of the gravity energy storage based on the number of units put into operation and the number of weight blocks that can be put into operation;

[0138] The electrochemical energy storage power estimation module is used to determine the power adjustment estimation range of the electrochemical energy storage based on the performance parameters and historical power data of the electrochemical energy storage.

[0139] The hybrid energy storage power evaluation module is used to determine the power evaluation of the gravity-electrochemical hybrid energy storage under the charging and discharging state based on the topological structure of the gravity-electrochemical hybrid energy storage and combining the power adjustment estimation range of the gravity energy storage and the electrochemical energy storage.

[0140] Furthermore, the gravity energy storage power estimation module includes:

[0141] Based on the number of energy storage units in operation, combined with the power change corresponding to a single weight block in the energy storage unit and the time interval required for switching adjacent weight blocks, the estimated adjustment power of the gravity energy storage within the evaluation period is determined;

[0142] Based on the number of weight blocks that can be put in, combined with the power change corresponding to a single weight block in the energy storage unit and the estimated adjustment power of the gravity energy storage during the evaluation period, the estimated power adjustment range of the gravity energy storage for exchanging power is determined.

[0143] Furthermore, the electrochemical energy storage power estimation module includes: determining the power adjustment estimation range of the electrochemical energy storage for output power based on the charge state, power capacity and historical output power of the electrochemical energy storage; and determining the power adjustment estimation range of the electrochemical energy storage for absorption power based on the charge state, power capacity and historical absorption power of the electrochemical energy storage.

[0144] Furthermore, the hybrid energy storage power evaluation module includes:

[0145] Based on the output power state characterization of the gravity-electrochemical hybrid energy storage and the estimated power adjustment range of the output power, the power evaluation of the gravity-electrochemical hybrid energy storage in the discharge state is determined; based on the absorption power state characterization of the gravity-electrochemical hybrid energy storage and the estimated power adjustment range of the absorption power, the power evaluation of the gravity-electrochemical hybrid energy storage in the charging state is determined.

[0146] Although preferred embodiments of the present invention have been described, additional changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are known. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A power evaluation method for gravity-electrochemical hybrid energy storage, characterized in that: include: Obtain the number of energy storage units in operation and the number of heavy blocks that can be put into operation for gravity energy storage; Determine the estimated range of power adjustment for gravity energy storage based on the number of units put into operation and the number of weight blocks that can be put into operation; Determine the estimated power adjustment range of electrochemical energy storage based on performance parameters and historical power data of electrochemical energy storage; Based on the topological structure of gravity-electrochemical hybrid energy storage and combining the power adjustment estimation range of gravity energy storage and electrochemical energy storage, the power evaluation of gravity-electrochemical hybrid energy storage under charging and discharging state is determined.

2. The power evaluation method according to claim 1, characterized in that: Based on the number of units put into operation and the number of weight blocks that can be put into operation, the estimated power adjustment range of gravity energy storage is determined, including: Based on the number of energy storage units in operation, combined with the power change corresponding to a single weight block in the energy storage unit and the time interval required for switching adjacent weight blocks, the estimated adjustment power of the gravity energy storage within the evaluation period is determined; Based on the number of weight blocks that can be put in, combined with the power change corresponding to a single weight block in the energy storage unit and the estimated adjustment power of the gravity energy storage during the evaluation period, the estimated power adjustment range of the gravity energy storage for exchanging power is determined.

3. The power evaluation method according to claim 2, characterized in that: The estimated adjustment power of gravity energy storage during the evaluation period satisfies the following relationship: Where, d gra is the estimated adjusted power of gravity energy storage during the evaluation period, n is the number of gravity energy storage units put into operation, P single is the power change corresponding to a single weight block, Δt is the evaluation period, ΔT gra The time interval required for switching between adjacent weight blocks.

4. The power evaluation method according to claim 2 or 3, characterized in that: The estimated power adjustment range of gravity energy storage for exchange power, including the estimated power adjustment range of gravity energy storage for output power and the estimated power adjustment range of gravity energy storage for absorption power; The estimated range of power adjustment for output power of gravity energy storage satisfies the following relationship: In the formula, and They are the maximum power and minimum power that the gravity energy storage estimates to be output to the grid at time t, is the number of weight blocks put into the nth unit when the gravity energy storage outputs power, d gra is the estimated adjusted power of gravity energy storage during the evaluation period, n is the number of gravity energy storage units put into operation, P single is the power change corresponding to a single weight block; The estimated range of power adjustment for absorbing power by gravity energy storage satisfies the following relationship: In the formula, and They are the maximum power and minimum power that gravity energy storage estimates to be absorbed from the grid at time t, The number of weight blocks put into the nth unit when absorbing power through gravity energy storage.

5. The power evaluation method according to claim 1, characterized in that: Based on the performance parameters and historical power data of the electrochemical energy storage, an estimated range of power adjustment of the electrochemical energy storage is determined, including: based on the state of charge, power capacity and historical output power of the electrochemical energy storage, an estimated range of power adjustment for the output power of the electrochemical energy storage is determined; and based on the state of charge, power capacity and historical absorption power of the electrochemical energy storage, an estimated range of power adjustment for the absorption power of the electrochemical energy storage is determined.

6. The power evaluation method according to claim 5, characterized in that: The estimated range of power adjustment for output power of electrochemical energy storage satisfies the following relationship: In the formula, and are the maximum power and minimum power that the electrochemical energy storage is estimated to output to the grid at time t, P Bess,d (t-1) is the power output of the electrochemical energy storage to the grid at time t-1, SOC(t) is the state of charge of the electrochemical energy storage at time t, SOC min is the minimum state of charge of electrochemical energy storage, Δt is the evaluation period, η d is the discharge efficiency of electrochemical energy storage, E rate is the power capacity of electrochemical energy storage; The estimated range of power adjustment for electrochemical energy storage to absorb power satisfies the following relationship: In the formula, and are the maximum power and minimum power that electrochemical energy storage can absorb from the grid at time t, P Bess,c (t-1) is the power absorbed by the electrochemical energy storage from the grid at time t-1, SOC max is the maximum state of charge of electrochemical energy storage, η c is the charging efficiency of electrochemical energy storage.

7. The power evaluation method according to claim 1 or 6, characterized in that: The topological structure of gravity-electrochemical hybrid energy storage satisfies the following relationship: 0≤ω gra,c +oh gra,d ≤1 0≤ω Bess,c +oh Bess,d ≤1 oh gra,c ·oh Bess,d +oh gra,d ·oh Bess,c =0 oh gra,c ,oh gra,d ∈{0,1} oh Bess,c ,oh Bess,d ∈{0,1} In the formula, ω gra,c Represents the absorption power state of gravity energy storage, when ω gra,c =1, the gravity energy storage is in the state of absorbing power. gra,c =0, the gravity energy storage is in an idle state; ω gra,d Represents the output power state of gravity energy storage, when ω gra,d =1, the gravity energy storage is in the output power state, when ω gra,d =0, the gravity energy storage is in an idle state; ω Bess,c Represents the absorption power state of electrochemical energy storage. When ω Bess,c =1, the electrochemical energy storage is in the state of absorbing power. Bess,c =0, the electrochemical energy storage is in an idle state; ω Bess,d Represents the output power state of electrochemical energy storage. When ω Bess,d =1, the electrochemical energy storage is in the output power state. Bess,d =0, the electrochemical energy storage is in idle state.

8. The power evaluation method according to claim 7, characterized in that: Based on the topological structure of gravity-electrochemical hybrid energy storage and combined with the power adjustment estimation range of gravity energy storage and electrochemical energy storage, the power evaluation of gravity-electrochemical hybrid energy storage under charging and discharging state is determined, including: Based on the output power state characterization of the gravity-electrochemical hybrid energy storage and the estimated power adjustment range of the output power, the power evaluation of the gravity-electrochemical hybrid energy storage in the discharge state is determined; based on the absorption power state characterization of the gravity-electrochemical hybrid energy storage and the estimated power adjustment range of the absorption power, the power evaluation of the gravity-electrochemical hybrid energy storage in the charging state is determined.

9. The power evaluation method according to claim 8, characterized in that: The power evaluation of gravity-electrochemical hybrid energy storage in the discharge state satisfies the following relationship: In the formula, Estimate the maximum power output to the grid at time t for gravity-electrochemical hybrid energy storage, Estimate the minimum power output to the grid at time t for gravity-electrochemical hybrid energy storage; The power evaluation of gravity-electrochemical hybrid energy storage in the charging state satisfies the following relationship: In the formula, Estimate the maximum power absorbed from the grid at time t for gravity-electrochemical hybrid energy storage, Estimate the minimum power absorbed from the grid at time t for gravity-electrochemical hybrid energy storage.

10. A power evaluation device for gravity-electrochemical hybrid energy storage, characterized in that: The power evaluation method of gravity-electrochemical hybrid energy storage as claimed in any one of claims 1 to 9 is adopted, and the power evaluation device comprises: A gravity energy storage configuration module, which is used to obtain the number of energy storage units corresponding to the gravity energy storage and the number of weight blocks that can be put into operation; A gravity energy storage power estimation module, which is used to determine the power adjustment estimation range of the gravity energy storage based on the number of units put into operation and the number of weight blocks that can be put into operation; The electrochemical energy storage power estimation module is used to determine the power adjustment estimation range of the electrochemical energy storage based on the performance parameters and historical power data of the electrochemical energy storage. The hybrid energy storage power evaluation module is used to determine the power evaluation of the gravity-electrochemical hybrid energy storage under the charging and discharging state based on the topological structure of the gravity-electrochemical hybrid energy storage and combining the power adjustment estimation range of the gravity energy storage and the electrochemical energy storage.

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