A method for energy storage capacity and installation time planning considering failure rate changes

Abstract

The application discloses a kind of energy storage capacity and installation time planning method considering failure rate change, comprising the following steps: 1 energy storage normal operating state is divided into healthy state and aging state;2 establish t Failure rate function of energy storage aging stage at any time;3 establish energy storage three-state space model considering aging state;4 equivalent is carried out to energy storage three-state space model, and the failure rate function of energy storage in the first m Period is obtained;5 propose the main function relationship of maximum charge-discharge power of energy storage, cycle number, ambient temperature and failure rate;6 calculate the capacity of energy storage added under the first m Period and the installation time of energy storage;7 the installation time of energy storage is corrected using sensitivity correction index.The application considers the influence of failure rate change of energy storage aging state on energy storage capacity, adds energy storage capacity for each period, and corrects installation time for each period, so as to realize the re-planning of energy storage capacity for next period, improve the reliability of power system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of power system planning, and particularly relates to a storage capacity and installation time planning method based on storage aging stage failure rate identification and power grid reliability sensitivity analysis. BACKGROUND

[0002] With the improvement of the electricity market and the demand for energy transformation, new energy is massively connected to the power grid, and storage devices play an increasingly important role in balancing power grid load, participating in peak shaving and frequency modulation, improving renewable energy utilization rate, and responding to power grid faults. As an important part of the power system, the capacity configuration and installation time planning of storage devices directly affect the reliability of the power system. In order to ensure that the storage system can quickly respond to sudden loads and power grid faults, and maximize the utilization rate of storage resources, scientific and reasonable capacity configuration and installation time planning of storage should be carried out.

[0003] At present, in the planning method of storage device capacity and installation time, the storage capacity and its installation time at different time stages are planned according to the load prediction results and the capacity balance relationship, but this method ignores the influence of the life decline of the storage aging stage and the increase of the storage failure rate on the capacity configuration, and only plans the capacity configuration and installation time of the storage without considering the change of the failure rate in the aging stage, which cannot timely add the corresponding capacity to meet the reliable operation of the power system. Therefore, in order to meet the reliable operation of the power system, it is of great significance to study the influence of the change of the failure rate of the storage aging stage on the capacity configuration of the storage. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the above-mentioned technology, and to provide a storage capacity and installation time planning method considering the change of failure rate, so as to consider the influence of the change of the failure rate of the storage aging state on the storage capacity on the basis of the planning of the storage capacity and installation time, add the storage capacity of each period, and correct the installation time of each period, so as to realize the re-planning of the storage capacity of the next period, and improve the reliability of the power system, thereby providing strong support for the storage planning.

[0005] In order to achieve the above-mentioned purpose of the application, the following technical scheme is adopted:

[0006] The storage capacity and installation time planning method considering the change of failure rate has the characteristics that the following steps are included:

[0007] Step S1: dividing the normal operation state of the storage into a healthy state and an aging state, and recording the change of the healthy state to the failure state as a random failure, and recording the change of the healthy state to the failure state after the aging state as an aging failure;

[0008] Step S2: The Weibull distribution is selected as the failure rate model for the energy storage aging stage, and the parameters of the failure rate model for the energy storage aging stage are identified using the recursive least squares method with a forgetting factor, thereby establishing... Failure rate function during the aging phase of energy storage ;

[0009] Step S3: Establish a three-state space model of energy storage that takes into account aging conditions, and introduce a random failure ratio. Thus obtain Failure rate function of energy storage from healthy state to fault state at any time Define the probability coefficient Thus, the failure rate function from healthy state to aging state is obtained. ;

[0010] Step S4: Equivalent the three-state space model of energy storage to a two-state space model, and based on the equality of state probabilities before and after equivalence, the equality of the frequency of transition to the fault state, and the balance of the frequency of aging states, obtain... Failure rate function of energy storage at any time And discretize it to obtain the first... Energy storage failure rate function for each cycle ;

[0011] Step S5: Taking the number of cycles, ambient temperature, and failure rate as influencing factors of energy storage capacity decay, establish sub-function relationships between the maximum charge and discharge power of energy storage and each influencing factor, thereby obtaining the main function relationship between the maximum charge and discharge power and each sub-function.

[0012] Step S6: Calculate the energy storage on the first step according to the master function relationship. Maximum power ratio per cycle Thus, the first Additional energy storage capacity per cycle And calculate the first Installation time of energy storage in each cycle ;

[0013] Step S7: Establish the first Power grid reliability indicators considering the aging phase over a single cycle And by making the energy storage capacity added periodically continuous, a system is established. The sensitivity of power grid reliability indicators, including the aging stage, to energy storage failure rate, energy storage capacity addition, and time under each cycle is analyzed, and the sensitivity of the first cycle to the aging stage is calculated. The increment of power grid reliability indicators considering the aging stage over a period of time , obtained the The correction time for energy storage in the first cycle is then obtained, thus yielding the first cycle. corrected energy storage installation time under the period.

[0014] The energy storage capacity and installation time planning method considering the change of failure rate has the characteristics that the step S2 comprises:

[0015] Step S2-1: taking the failure rate model of the energy storage aging stage on both sides simultaneously, thereby constructing the fitting polynomial by using formula (1):

[0016] (1)

[0017] In formula (1), is the current time; is the failure rate function of the energy storage aging state to the failure state at the time t; , are the estimated values of the first constant and the second constant respectively;

[0018] Step S2-2: the two parameters and in formula (1) are identified by using the recursive least square method with a forgetting factor, the two estimated values and are obtained, and are substituted into the failure rate model of the energy storage aging stage, thereby establishing the failure rate function of the energy storage aging state to the failure state at the time t, that is, the failure rate function of the energy storage aging stage by using formula (2):

[0019] (2).

[0020] Further, the step S3 comprises:

[0021] Step S3-1: establishing an energy storage three-state space model considering the aging state, comprising: the failure rate function of the energy storage healthy state to the aging state at the time t , the failure rate function of the energy storage aging state to the failure state at the time t , the failure rate function of the energy storage healthy state to the failure state at the time t , the repair rate of the failure state to the healthy state ;

[0022] Step S3-2: introducing the random failure proportion , thereby constructing the failure rate function of the energy storage healthy state to the failure state at the time t by using formula (3): ​:

[0023] (3)

[0024] In formula (3), is the failure rate function of the energy storage from the healthy state to the failure state at time t;

[0025] Step S3-3: the state transition rate of the energy storage from the healthy state to the aging state and then to the failure state at time t is denoted as and the constraint condition is constructed by using formula (4):

[0026] (4)

[0027] Step S3-4: the possibility coefficient is defined as , which represents the possibility of the energy storage developing from the aging state to the failure state, and , the failure rate function of the energy storage from the healthy state to the aging state at time t is constructed by using formula (5):

[0028] (5).

[0029] Further, the step S4 includes:

[0030] Step S4-1: the energy storage three-state space model considering the aging state is equivalent to a two-state space model, including: the failure rate function of the energy storage from the healthy state to the failure state at time t , and the repair rate of the energy storage from the failure state to the healthy state

[0031] Step S4-2: the failure rate function of the energy storage from the healthy state to the failure state at time t is obtained by using formula (6):

[0032] (6)

[0033] Step S4-3: the failure rate function of the energy storage at the nth cycle is obtained by using formula (7):

[0034] (7)

[0035] In formula (7), represents the total period of each cycle; is a positive integer.

[0036] ​​​​​​​​​Further, the step S5 comprises:

[0037] Step S5-1: obtaining a sub-function relationship between the maximum charge-discharge power and the energy storage cycle number according to experimental data;

[0038] Step S5-2: taking the standard temperature of the measurement environment as a reference value, and using formula (8) to obtain the maximum charge-discharge power corresponding to any environmental temperature , and the ratio of the maximum charge-discharge power of the energy storage to the reference value

[0039] (8)

[0040] In formula (8), is the environmental temperature corresponding to the maximum charge-discharge power;

[0041] A sub-function relationship between the maximum charge-discharge power and the environmental temperature is established by using formula (9):

[0042] (9)

[0043] In formula (9), is the maximum charge-discharge power; is a set of typical temperatures in a period; is the probability of any one of the typical temperature sets appearing in a period;

[0044] Step S5-3: a sub-function relationship between the maximum charge-discharge power of the energy storage and the failure rate in the nth period is established by using formula (10):

[0045] (10) Step S5-4: a main function relationship between the maximum charge-discharge power of the energy storage and each sub-function relationship in the nth period is constructed by using formula (11):

[0046]

[0047] (11)

[0048] In formula (11), , , are three fitting coefficients; is the average charge-discharge number in a period.

[0049] Further, the step S6 comprises: ​​​​​​​​

[0050] Step S6-1: obtaining the maximum power ratio of the energy storage in the first cycle

[0051] Step S6-2: calculating the comprehensive maximum power ratio of the energy storage in the first cycle by using formula (12)

[0052] (12)

[0053] In formula (12), is a function about the maximum power ratio; is the capacity added to the energy storage in the first cycle, is the comprehensive maximum power ratio of the energy storage in the first cycle; Step S6-3: obtaining the capacity added to the energy storage in the first cycle by using formula (13)

[0054]

[0055] (13)

[0056] In formula (13), is the maximum power ratio of the energy storage in the first cycle, and ; is the capacity added to the energy storage in the first cycle, i.e. the initial capacity of the energy storage;

[0057] Step S6-4: obtaining the installation time of the energy storage in the first cycle by using formula (14)

[0058] (14)

[0059] In formula (14), is the installation time of the energy storage in the first cycle, i.e. the initial installation time of the energy storage.

[0060] Further, the step S7 comprises:

[0061] Step S7-1: constructing the power grid reliability index in the first cycle considering the aging stage by using formula (15) based on the fault enumeration and the probability weighting algorithm ​​​​​​​​​​​​​​​

[0062] (15)

[0063] In formula (15): is the set of failure time in the th cycle; represents the th cycle when the energy storage fails at time , the probability of energy storage normal operation at time ; represents the failure rate function of energy storage at time ; represents the load increment at time ; is the repair rate from failure state to normal state, and ;

[0064] Step S7-2: the sensitivities of the grid reliability index considering the aging stage to the failure rate and time of energy storage in the th cycle are respectively established by using formula (16) and formula (17):

[0065] (16)

[0066] (17)

[0067] Step S7-3: according to the capacity of energy storage added in the previous th cycle, the interpolation polynomial at time is constructed by using the Lagrange interpolation method to complete the continuity of the capacity of energy storage added cycle by cycle;

[0068] Step S7-4: the sensitivity analytical expression of the grid reliability index considering the aging stage to the failure rate of energy storage in the th cycle is established by using formula (18):

[0069] (18)

[0070] Step S7-5: the increment of the grid reliability index considering the aging stage in the th cycle is established by using formula (19):

[0071] (19)

[0072] Step S7-6: the modified time of energy storage in the th cycle is obtained by using formula (20):

[0073] (20)

[0074] Step S7-7: obtain the corrected installation time of the energy storage in the first period by using formula (21) :

[0075] (21)

[0076] In formula (21), is the installation time of the energy storage in the first period.

[0077] The electronic device comprises a memory and a processor, and the memory is used to store a program supporting the processor to execute the energy storage capacity and installation time planning method, and the processor is configured to execute the program stored in the memory.

[0078] The computer readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the energy storage capacity and installation time planning method are executed.

[0079] Compared with the prior art, the energy storage capacity and installation time planning method provided by the present application has the following beneficial effects:

[0080] 1. The energy storage capacity and installation time planning method provided by the present application can consider the influence of the aging stage life of the energy storage device on the energy storage capacity configuration, establish a failure rate model of the energy storage aging stage, identify the parameters of the failure rate model by using a recursive least square method with a forgetting factor, obtain a failure rate function of the energy storage aging stage, and provide a basis for obtaining the failure rate function of the energy storage.

[0081] 2. The energy storage capacity and installation time planning method provided by the present application can establish an energy storage three-state space model considering the aging state by dividing the normal operation state of the energy storage into a healthy state and an aging state, obtain a failure rate function of the energy storage according to the failure rate function of the aging stage and the equivalence of the state space, and provide a basis for the reliability analysis of the energy storage.

[0082] 3. The energy storage capacity and installation time planning method provided by the present application can propose a power grid reliability index considering the aging stage, derive a sensitivity analytical expression of the reliability index to the failure rate of the energy storage, the additional capacity of the energy storage and time, calculate the increment of the power grid reliability index, obtain a corrected time of the energy storage, correct the installation time of the energy storage, and improve the reliability of the energy storage. BRIEF DESCRIPTION OF DRAWINGS

[0083] ​​Figure 1 Flow chart of the present application;

[0084] Figure 2 Fault rate curve of the present application from stable operation stage to aging stage;

[0085] Figure 3 Three-state space model of the present application considering aging state and its equivalent;

[0086] Figure 4 Installation time correction chart of the present application. DETAILED DESCRIPTION

[0087] In this embodiment, a storage capacity and installation time planning method considering fault rate change is proposed, which is to propose a fault rate model of the storage in the aging stage and identify the parameters thereof, to establish a three-state space model of the storage considering the aging state and deduce a fault rate function of the storage, to propose a main function relationship among the maximum charge-discharge power of the storage, the cycle number, the environmental temperature and the fault rate, to calculate the maximum power ratio of the storage to plan the capacity of the storage device, to perform reliability evaluation and sensitivity analysis on the storage device considering the aging state, and to correct the installation time of the storage, thereby effectively improving the reliability of the storage capacity configuration. Specifically, as shown in Figure 1 The method comprises the following steps:

[0088] Step S1: dividing the normal operation state of the storage into a healthy state and an aging state, and recording the change of the healthy state directly to a fault state as a random fault, which is mainly caused by external factors such as manual misoperation, and recording the change of the healthy state to a fault state through the aging state as an aging fault, which is mainly caused by internal factors such as natural aging of the storage with the increase of the operation time;

[0089] Step S2: selecting Weibull distribution as the fault rate model of the storage in the aging stage, deforming the fault rate model, constructing a fitting polynomial satisfying the least square method, and identifying the parameters of the fault rate model of the storage in the aging stage by using a recursive least square method with a forgetting factor, thereby establishing the fault rate function of the storage in the aging stage at any time .

[0090] Step S2-1: the fault rate change of the storage from the stable operation stage to the aging stage is as shown in Figure 2 , wherein the stable operation stage corresponds to the healthy state, and the aging stage corresponds to the aging state. Considering that the fault rate of the storage in the aging stage increases over time, Weibull distribution is introduced, and the fault rate model of the storage in the aging stage is established by using formula (1):

[0091] (1)

[0092] in formula (1), is the current time; is a failure rate function of the energy storage aging state to the failure state at time is a first constant; is a second constant, and at this time, the failure rate has an increasing characteristic, satisfying the change characteristic of the energy storage failure rate in the aging stage.

[0093] Step S2-2: taking the logarithm of both sides of the failure rate model in the energy storage aging stage, thereby constructing a fitting polynomial using formula (2):

[0094] (2)

[0095] in formula (2), , are the estimated values of the first constant and the second constant .

[0096] Step S2-3: write formula (2) in vector form:

[0097] (3)

[0098] in formula (3), is an output vector; is an information vector; is a parameter vector to be identified.

[0099] Step S2-4: define an index function as the sum of the distances of each point to the fitting polynomial, in order to weaken the influence of data saturation, introduce a forgetting factor to reduce the role of old data, and construct an error sum of squares using formula (4):

[0100] (4)

[0101] Step S2-5: the least square method requires that the error sum of squares is minimum, minimize formula (4), thereby obtaining a recursive least square identification formula with a forgetting factor using formula (5):

[0102] (5)

[0103] in formula (5), is a parameter estimate value; is a gain vector; is an identity matrix; is a covariance matrix; ​For the forgetting factor, usually take 0.95~1 between.

[0104] Step S2-6: Set initial value , and let , where is a sufficiently small positive real vector or zero vector, is a sufficiently large positive real number, is an identity matrix;

[0105] Step S2-7: By constantly obtaining new energy storage failure rate, the newly obtained data is substituted into equation (5) to iterate, constantly correct the original estimate, get the parameters and , and use equation (6) to get the estimated value and :

[0106] (6)

[0107] Step S2-8: Substitute the two estimated values and into the failure rate model, thereby using equation (7) to establish The failure rate function of the energy storage aging state to the failure state at time , that is, the failure rate function of the energy storage aging stage :

[0108] (7)

[0109] Step S3: Establish an energy storage three-state space model considering aging state, and introduce a random failure rate , thereby obtaining The failure rate function of the energy storage from the healthy state to the failure state at time , define the possibility coefficient , thereby obtaining the failure rate function of the healthy state to the aging state .

[0110] Step S3-1: Establish an energy storage three-state space model considering aging state, as shown in Figure 3 , including: HC, AC, FC are the healthy state, aging state and failure state of the energy storage respectively; The failure rate function of the energy storage from the healthy state to the aging state at time ; The failure rate function of the energy storage from the aging state to the failure state at time ; The failure rate function of the energy storage from the healthy state to the failure state at time ; The repair rate of the failure state to the healthy state ;

[0111] Step S3-2: Introduce random failure ratio Thus, using equation (8) to construct Failure rate function of energy storage from healthy state to fault state at any time :

[0112] (8)

[0113] In equation (8), for The failure rate function of energy storage from normal state to fault state at any time, i.e., the failure rate function of energy storage;

[0114] Step S3-3: ... The state transition rate of energy storage from a healthy state to an aging state and then to a fault state is denoted as . Considering that aging does not necessarily lead to failure, we construct constraints using equation (9):

[0115] (9)

[0116] Step S3-4: Define the probability coefficient This indicates the possibility of energy storage evolving from an aging state to a failure state, and Then, using equation (10) to construct Failure rate function of energy storage from healthy state to aging state at any time :

[0117] (10)

[0118] Step S4: Equivalent the three-state space model of energy storage to a two-state space model. Based on the equality of state probabilities before and after equivalence, the equality of the frequency of transition to the fault state, and the balance of the frequency of aging states, we obtain... Failure rate function of energy storage at any time And discretize it to obtain the first... Energy storage failure rate function for each cycle .

[0119] Step S4-1: Equivalent the three-state space model of energy storage considering aging to a two-state space model, such as... Figure 3 As shown, UP and FC represent the normal and fault states of energy storage, respectively. Failure rate function of energy storage from normal state to fault state at any time Repair rate from fault state to normal state ;

[0120] Step S4-2: the equivalent pre and post state probabilities are equal, the equivalent pre and post transition frequencies to the fault state are equal, and the aging state frequency is balanced, as shown in formula (11), formula (12), formula (13):

[0121] (11)

[0122] (12)

[0123] (13)

[0124] In formula (11), , are state probabilities of the energy storage health state and the energy storage aging state, respectively; is a state probability of the energy storage normal operation state, and the state transition rate matrix of the energy storage is , and the state probability of the energy storage normal operation is obtained by using formula (14):

[0125] (14)

[0126] Step S4-3: formula (11), formula (12), and formula (13) are solved simultaneously, and , , are substituted into formula (11), formula (12), and formula (13), so that the failure rate function of the energy storage normal state to the fault state at time is obtained by using formula (15):

[0127] (15)

[0128] Step S4-4: the energy storage failure rate is integrated and averaged on the time interval , and the failure rate function of the energy storage in the nth period is obtained by using formula (16):

[0129] (16)

[0130] In formula (16), represents the total period of each period; is a positive integer;

[0131] Step S5: the cycle number, the environmental temperature, and the failure rate are taken as the influencing factors of the capacity attenuation of the energy storage, and a sub-function relationship formula between the maximum charge and discharge power of the energy storage and each influencing factor is established, so that a main function relationship formula of the maximum charge and discharge power and each sub-function relationship is obtained.

[0132] ​​​Step S5-1: The maximum charge-discharge power of the energy storage is reduced in each charge-discharge process. According to experimental data, the sub-function relationship between the maximum charge-discharge power and the cycle number of the energy storage is obtained by using formula (17):

[0133] (17)

[0134] In formula (17), Pmaxis the maximum charge-discharge power; are three fitting coefficients, which can be obtained according to the charge-discharge power distribution data of the same type of energy storage under the provided external temperature and the probability of the temperature appearing in a cycle.

[0135] Step S5-2: The standard temperature of the environment is taken as a measurement The corresponding maximum charge-discharge power Pmaxis the reference value, and the ratio of the maximum charge-discharge power of the energy storage to the reference value under any environmental temperature is obtained by using formula (18):

[0136] (18)

[0137] In formula (18), T is the environmental temperature corresponding to the maximum charge-discharge power. The sub-function relationship between the maximum charge-discharge power and the environmental temperature is established by using formula (19):

[0138]

[0139] (19)

[0140] In formula (19), T is a set of typical temperatures in a cycle; is the probability of any one set of typical temperatures appearing in a cycle.

[0141] Step S5-3: The sub-function relationship between the maximum charge-discharge power of the energy storage and the failure rate in the nth cycle is established by using formula (20):

[0142] (20)

[0143] Step S5-4: The main function relationship between the maximum charge-discharge power of the energy storage and the sub-function relationship in the nth cycle is constructed by using formula (21):

[0144] ​​​​​​​​​​​​​(twenty one)

[0145] In equation (21), The average number of charge-discharge cycles in one cycle.

[0146] Step S6: Calculate the energy storage on the first step according to the master function relationship. Maximum power ratio per cycle Thus, the first Additional energy storage capacity per cycle And calculate the first Installation time of energy storage in each cycle .

[0147] Step S6-1: Calculate the first... Maximum charge / discharge power of energy storage during each cycle With the maximum charge and discharge power of energy storage in the first cycle The ratio of the two values ​​can be used to obtain the energy storage value in the first step using equation (22). Maximum power ratio per cycle :

[0148] (twenty two)

[0149] Step S6-2: Use equation (23) to construct the relationship between energy storage capacity decay and energy storage capacity addition in each cycle:

[0150] (twenty three)

[0151] In equation (23), This represents the maximum power ratio of energy storage in the first cycle. ; It is a positive integer, and ; The additional capacity added for the first cycle of energy storage, i.e. the capacity initially configured for energy storage; For the first Additional capacity for energy storage in each cycle.

[0152] Step S6-3: Write equation (24) according to equation (23). For ease of representation, introduce the first... The combined maximum power ratio of each cycle :

[0153] (twenty four)

[0154] Step S6-4: Derive the energy storage in the first step according to equation (24). The combined maximum power ratio under each cycle ;

[0155] (25)

[0156] In equation (25), It is a function of the maximum power ratio. For the first Additional energy storage capacity per cycle For energy storage in the first The combined maximum power ratio over each cycle.

[0157] Step S6-5: Combining equations (24) and (25), we obtain the first... Additional energy storage capacity per cycle :

[0158] (26)

[0159] Step S6-6: Use equation (27) to obtain the first... Installation time of energy storage in each cycle :

[0160] (27)

[0161] In equation (27), This refers to the installation time of energy storage in the first cycle, i.e., the installation time of the initial configuration of energy storage.

[0162] Step S7: Establish the first Power grid reliability indicators considering the aging phase over a single cycle This involves making the periodic addition of energy storage capacity continuous, thereby establishing the first... The sensitivity of power grid reliability indicators, including the aging stage, to energy storage failure rate, energy storage capacity addition, and time under each cycle is analyzed, and the sensitivity of the first cycle to the aging stage is calculated. The increment of power grid reliability indicators considering the aging stage over a period of time , obtained the The correction time for energy storage in the first cycle is then obtained, thus yielding the first cycle. Corrected energy storage installation time under each cycle.

[0163] Step S7-1: Based on fault enumeration and probability weighting algorithm, construct the first fault using equation (15). Power grid reliability indicators considering the aging phase over a single cycle :

[0164] (28)

[0165] In equation (28): For the first The set of fault moments under each cycle; Indicates the first Under each cycle If the energy storage fails at any time, The probability of the energy storage operating normally at all times, and ; express Failure rate function of energy storage at all times; express The load increment at any given time; The recovery rate from a faulty state to a normal state. ;

[0166] Step S7-2: Use equations (29) and (30) to establish the first... Analysis of the sensitivity of power grid reliability indicators to energy storage failure rate and time, considering the aging stage over a single cycle:

[0167] (29)

[0168] (30)

[0169] Step S7-3: Based on the previous The additional energy storage capacity per cycle is constructed using Lagrange interpolation. Time-interpolation polynomial This is to achieve continuous capacity addition for energy storage on a cycle-by-cycle basis;

[0170] (31)

[0171] Step S7-4: Use equation (32) to establish the first Analytical expression of the sensitivity of power grid reliability indicators to energy storage failure rate over a period of time, taking into account the aging stage:

[0172] (32)

[0173] Step S7-5: Use equation (33) to establish the first Increment of power grid reliability indicators considering the aging phase over a given period :

[0174] (33)

[0175] Step S7-6: Use equation (34) to obtain the first... Correction time for energy storage per cycle :

[0176] (34)

[0177] Step S7-7: Use equation (35) to obtain the first... Corrected energy storage installation time under each cycle ,likeFigure 4 As shown, where The capacity configured for energy storage; For the first The additional capacity required for energy storage in a given cycle; if no additional capacity is required in that cycle, then... ; For the first Installation time of energy storage before correction in each cycle; For the first Corrected energy storage installation time under each cycle:

[0178] (35)

[0179] In this embodiment, an electronic device includes a memory and a processor. The memory stores a program that supports the processor in executing the above-described method, and the processor is configured to execute the program stored in the memory.

[0180] In this embodiment, a computer-readable storage medium stores a computer program, which is executed by a processor to perform the steps of the above method.

Claims

1. A method for planning energy storage capacity and installation time taking into account changes in failure rate, characterized in that, Includes the following steps: Step S1: Divide the normal operating state of energy storage into healthy state and aging state, and record the change from healthy state to fault state directly as random fault, and the change from healthy state to fault state after aging state as aging fault. Step S2: The Weibull distribution is selected as the failure rate model for the energy storage aging stage, and the parameters of the failure rate model for the energy storage aging stage are identified using the recursive least squares method with a forgetting factor, thereby establishing... Failure rate function during the aging phase of energy storage ; Step S2-1: Take the logarithm of both sides of the failure rate model during the energy storage aging stage, and then use equation (1) to construct the fitting polynomial: (1) In equation (1), The current moment; for The failure rate function from the aging state to the fault state of the energy storage at any time; , The first constants are respectively Second constant The estimated value; Step S2-2: Use the recursive least squares method with forgetting factor to evaluate the two parameters in equation (1). and Identify and obtain two estimated values. and ; Step S3: Establish a three-state space model of energy storage that takes into account aging conditions, and introduce a random failure ratio. Thus obtain Failure rate function of energy storage from healthy state to fault state at any time Define the probability coefficient Thus, the failure rate function from healthy state to aging state is obtained. ; Step S4: Equivalent the three-state space model of energy storage to a two-state space model, and based on the equality of state probabilities before and after equivalence, the equality of the frequency of transition to the fault state, and the balance of the frequency of aging states, obtain... Failure rate function of energy storage at any time And discretize it to obtain the first Energy storage failure rate function for each cycle ; Step S4-1: Equip the three-state space model of energy storage, which takes into account aging, into a two-state space model, including: Failure rate function of energy storage from normal state to fault state at any time Repair rate from fault state to normal state ; Step S4-2: Obtain using equation (6) Failure rate function of energy storage from normal state to fault state at any time : (6) Step S4-3: Use equation (7) to obtain the first... Failure rate function of energy storage in one cycle : (7) In equation (7), Indicates the total time period for each cycle; It is a positive integer; probability coefficient This indicates the possibility of energy storage evolving from an aging state to a failure state, and ; Step S5: Taking the number of cycles, ambient temperature, and failure rate as influencing factors of energy storage capacity decay, establish sub-function relationships between the maximum charge and discharge power of energy storage and each influencing factor, thereby obtaining the main function relationship between the maximum charge and discharge power and each sub-function. Step S5-1: Based on the experimental data, obtain the maximum charge / discharge power and the number of energy storage cycles. The sub-function relation; Step S5-2: Measure the standard temperature of the environment. Corresponding maximum charge and discharge power Using the baseline value, any ambient temperature can be obtained using equation (8). Below, the ratio of the maximum charge / discharge power of energy storage to the benchmark value. : (8) In equation (8), For ambient temperature The corresponding maximum charge and discharge power; Using equation (9), establish the sub-function relationship between maximum charge / discharge power and ambient temperature: (9) In equation (9), This is the maximum charge / discharge power; Within a cycle A typical temperature set; The probability of any typical temperature set occurring within a period; Step S5-3: Use equation (10) to establish the first The sub-function relationship between the maximum charge / discharge power of energy storage and the failure rate over a given cycle is as follows: (10) Step S5-4: Construct the first using equation (11) Maximum charge / discharge power of energy storage during each cycle The main function relation relating to each sub-function is as follows: (11) In equation (11), , , There are 3 fitting coefficients; The average number of charge-discharge cycles per cycle; Step S6: Calculate the energy storage on the first step according to the master function relationship. Maximum power ratio per cycle Thus, the first Additional energy storage capacity per cycle And calculate the first Installation time of energy storage in each cycle ; Step S6-1: Calculate the first... Maximum charge / discharge power of energy storage during each cycle With the maximum charge and discharge power of energy storage in the first cycle The ratio of the two values ​​is used to obtain the energy storage in the first stage. Maximum power ratio per cycle ; Step S6-2: Calculate the energy storage in the first step using equation (12). The combined maximum power ratio under each cycle ; (12) In equation (12), It is a function of the maximum power ratio; For the first Additional energy storage capacity per cycle For energy storage in the first The combined maximum power ratio under each cycle; Step S6-3: Use equation (13) to obtain the first... Additional energy storage capacity per cycle : (13) In equation (13), This represents the maximum power ratio of energy storage in the first cycle, and ; The additional capacity added for the first cycle of energy storage, i.e. the capacity initially configured for energy storage; Step S6-4: Use equation (14) to obtain the first... Installation time of energy storage in each cycle : (14) In equation (14), This refers to the installation time of energy storage in the first cycle, i.e., the installation time of the initial configuration of energy storage. Step S7: Establish the first Power grid reliability indicators considering the aging phase over a single cycle And by making the energy storage capacity added periodically continuous, a system is established. The sensitivity of power grid reliability indicators, including the aging stage, to energy storage failure rate, energy storage capacity addition, and time under each cycle is analyzed, and the sensitivity of the first cycle to the aging stage is calculated. The increment of power grid reliability indicators considering the aging stage over a period of time , obtained the The correction time for energy storage in the first cycle is then obtained, thus yielding the first cycle. Corrected energy storage installation time under each cycle; Step S7-1: Based on fault enumeration and probability weighting algorithm, construct the first fault using equation (15). Power grid reliability indicators considering the aging phase over a single cycle : (15) In equation (15): For the first The set of fault moments under each cycle; Indicates the first Under each cycle If the energy storage fails at any time, The probability of the energy storage operating normally at all times, and ; express Failure rate function of energy storage at all times; express The load increment at any given time; This represents the recovery rate from a faulty state to a normal state, and ; The recovery rate from a faulty state to a healthy state; Step S7-2: Use equations (16) and (17) to establish the first... Analysis of the sensitivity of power grid reliability indicators to energy storage failure rate and time, considering the aging stage over a single cycle: (16) (17) Step S7-3: Based on the previous The additional energy storage capacity per cycle is constructed using Lagrange interpolation. Time-interpolation polynomial This is to achieve continuous capacity addition for energy storage on a cycle-by-cycle basis; Step S7-4: Use equation (18) to establish the first Analytical expression of the sensitivity of power grid reliability indicators to energy storage failure rate over a period of time, taking into account the aging stage: (18) Step S7-5: Use equation (19) to establish the first Increment of power grid reliability indicators considering the aging phase over a given period : (19) Step S7-6: Use equation (20) to obtain the first... Correction time for energy storage per cycle : (20) Step S7-7: Use equation (21) to obtain the first... Corrected energy storage installation time under each cycle : (21) In equation (21), For the first Installation time of energy storage under each cycle.

2. The energy storage capacity and installation time planning method considering failure rate variations according to claim 1, characterized in that, In step S2-2, the two estimated values ​​are... and And substitute it into the failure rate model of the energy storage aging stage, so as to establish using equation (2) The failure rate function from the aging state to the fault state of energy storage at any given moment, i.e., the failure rate function of the energy storage aging stage. : (2)。 3. The energy storage capacity and installation time planning method considering failure rate variations according to claim 2, characterized in that, Step S3 includes: Step S3-1: Establish a three-state space model of energy storage that takes into account aging conditions, including: Failure rate function of energy storage from healthy state to aging state at any time , Failure rate function from energy storage aging state to fault state at any time , Failure rate function of energy storage from healthy state to fault state at any time ; Step S3-2: Introduce random failure ratio Thus, using equation (3) to construct Failure rate function of energy storage from healthy state to fault state at any time : (3) In equation (3), for The failure rate function of energy storage from normal state to fault state at any time, i.e., the failure rate function of energy storage; Step S3-3: [The text appears to be incomplete and contains several grammatical errors. A more accurate translation would require The state transition rate of energy storage from a healthy state to an aging state and then to a fault state is denoted as . And use equation (4) to construct the constraints: (4) Step S3-4: Construct using equation (5) Failure rate function of energy storage from healthy state to aging state at any time : (5)。 4. An electronic device, comprising a memory and a processor, characterized in that, The memory is used to store a program that supports the processor in executing the energy storage capacity and installation time planning method of any one of claims 1-3, and the processor is configured to execute the program stored in the memory.

5. A computer-readable storage medium storing a computer program thereon, characterized in that, When the computer program is run by the processor, it performs the steps of the energy storage capacity and installation time planning method according to any one of claims 1-3.

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