A decision-making method for preventive maintenance interval of single offshore wind power components

Abstract

The present invention discloses a preventive maintenance interval decision method for a single offshore wind power component, comprising the following steps: according to the analysis of historical failure data of the component, using Weibull distribution to fit the failure rate distribution function of the single component of the wind turbine; introducing an age decreasing factor and a failure rate increasing factor, and calculating the relationship between the failure rate corresponding to the i-th preventive maintenance of the single component and the failure rate corresponding to the i+1-th preventive maintenance; based on a maintenance threshold, calculating the interval of each preventive maintenance; calculating the maintenance cost of the component per unit time, and calculating the best maintenance plan of the component within the life cycle through an optimization algorithm, so as to determine the best preventive maintenance times of the component; after determining the best preventive maintenance times, simulating the maintenance process, obtaining the maintenance interval and the maintenance cost, and evaluating whether it meets the needs of the wind farm, and if so, determining the decision parameters, and if not, adjusting the preventive maintenance strategy and re-optimizing the parameters.

Description

Technical Field

[0001] The present invention belongs to the field of offshore wind power foundation, and in particular relates to a method for making decisions on preventive maintenance intervals of single offshore wind power components. Background Art

[0002] Offshore wind farms have shown great potential in wind energy utilization due to their high average wind speed, high annual utilization hours, and large single-unit capacity of wind turbines. However, their operating environment is harsh, and the equipment is susceptible to natural conditions such as salt spray, typhoons, and waves, which accelerates the failure of wind turbine components and significantly increases the equipment failure rate. In addition, offshore wind and wave conditions limit the accessibility of wind farms, making operation and maintenance more difficult, extending the unit downtime and reducing the availability. In this context, the operation and maintenance costs of wind turbines, including failure costs, maintenance costs, and personnel costs, have increased significantly. Therefore, in order to ensure the economical and efficient operation of offshore wind farms, it is necessary to seek innovative maintenance strategies to improve the reliability of wind turbines, reduce failure rates, and increase availability, thereby controlling and reducing overall operation and maintenance costs.

[0003] In response to this challenge, this paper proposes a decision method for the preventive maintenance interval of a single offshore wind turbine component. Based on the preventive maintenance model of a single wind turbine component with Weibull distribution, it comprehensively considers the historical failure data of the component, the effect of incomplete maintenance and the maintenance cost, and aims to scientifically plan maintenance activities through advanced optimization algorithms, determine the optimal number of preventive maintenance and maintenance intervals, and achieve the best balance between maintenance costs and maintenance effects. This is intended to overcome the drawbacks of traditional regular maintenance strategies that ignore the actual use status and failure modes of components, realize the refinement and scientificization of wind turbine operation and maintenance strategies, and further improve the operating efficiency and economy of offshore wind farms. Summary of the invention

[0004] In order to make up for the deficiencies of the prior art, the present invention aims to provide a method for deciding the preventive maintenance interval of a single offshore wind power component, so as to solve the problems of high operation and maintenance cost of wind turbines, great difficulty in operation and maintenance, long unit downtime, and reduced availability.

[0005] The technical problem solved by the present invention can be achieved through the following technical solutions:

[0006] The offshore wind power single component preventive maintenance interval decision method comprises the following steps:

[0007] S1. Based on the analysis of historical failure data of components, the failure rate distribution function of a single component of a wind turbine is fitted using Weibull distribution;

[0008] S2. Introduce the service age reduction factor m i and the failure rate increasing factor n i, calculate the relationship between the failure rate corresponding to the i-th preventive maintenance of a single component and the failure rate corresponding to the i+1-th preventive maintenance;

[0009] S3. Based on the maintenance threshold R p , calculate the interval T of each preventive maintenance i ;

[0010] S4. Calculate the maintenance cost E of the component per unit time, and calculate the optimal maintenance plan of the component within the life cycle through the optimization algorithm, so as to determine the optimal preventive maintenance times N of the component;

[0011] S5. After determining the optimal number of preventive maintenance times N, simulate the maintenance process to obtain the maintenance interval and maintenance cost, and evaluate whether it meets the needs of the wind farm. If it does, determine the decision parameters. If it does not, adjust the preventive maintenance strategy and re-optimize the parameters.

[0012] Furthermore, in step S1, according to the analysis of the historical fault data of the component, the shape parameter β and the scale parameter α of the Weibull distribution corresponding to the historical fault data are fitted by function, and the failure rate distribution function of the single component of the wind turbine is fitted by using the Weibull distribution:

[0013]

[0014] In the formula, t refers to a certain time on the time axis as a variable.

[0015] Furthermore, in step S2, the relationship between the failure rate corresponding to the i-th preventive maintenance of a single component and the failure rate corresponding to the i+1-th preventive maintenance is:

[0016] λ i+1 (t) = n i λ i (t+m i T i )t∈(0,T (i+1) ),

[0017] Where, T i Refers to the time point of the i-th maintenance, 0<m i <1, n i >1, service age reduction factor m i and the failure rate increasing factor n i The value of is usually determined empirically.

[0018] Furthermore, in step S3, when the reliability value of a single component of the wind turbine generator set is less than or equal to the set maintenance threshold R corresponding to the incomplete maintenance, p When the fan is repaired, the reliability equation of a single component is:

[0019]

[0020] You can also write:

[0021]

[0022] In the formula, Represents the cumulative probability of failure during the i-th maintenance interval. When reliability is used as a constraint, the minimum number of maintenance times for a single component in each maintenance cycle is equal, and its value is -lnR p , so the interval T of each preventive maintenance can be calculated i .

[0023] Furthermore, in step S4, it is stipulated that the number of times the incomplete maintenance method is adopted for the component within the operation cycle T is N, and the maintenance cost E of the component per unit time is:

[0024]

[0025] Among them, C p is the component preventive maintenance cost, C t is the preventive replacement maintenance cost of components, C f is the component failure repair cost, C d is the maintenance cost per unit time of the component, and t is the time taken for different maintenance methods of the component; the component preventive maintenance model equation is as follows:

[0026]

[0027] The restrictions are as follows:

[0028]

[0029] R p >0,

[0030] N>0,

[0031] i=1,2,···,N,

[0032] T i >0,

[0033] The optimal maintenance plan for the component during its life cycle is calculated by minimizing the objective function E, thereby determining the optimal number of preventive maintenance times N for the component.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] (1) The present invention adopts Weibull distribution to fit the failure rate distribution of components, which fully considers the change law of component failure over time. Compared with the traditional fixed time interval maintenance strategy, it can more accurately reflect the actual failure mode of the components and improve the scientificity and accuracy of the maintenance strategy.

[0036] (2) By introducing the service life decreasing factor and the failure rate increasing factor, the model of the present invention can quantify the impact of incomplete maintenance on the service life and failure rate of components, and then comprehensively consider the preventive maintenance cost, replacement cost and failure repair cost in the optimization process, seek to minimize the total maintenance cost, and achieve the maximization of the economic benefits of maintenance.

[0037] (3) The model of the present invention is not only applicable to specific wind turbine components, but can also be flexibly applied to different types of wind turbines and components by adjusting parameters and constraints, and has strong versatility and adaptability.

[0038] (4) The model of the present invention also includes the simulation of the maintenance process and the evaluation of the maintenance effect, which can provide wind farm operators with intuitive maintenance plans and cost budgets, making it easier for decision makers to adjust maintenance strategies according to actual conditions and ensure the effectiveness and economy of maintenance plans. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] like Figure 1 As shown, a method for making decisions on preventive maintenance intervals for a single offshore wind power component comprises the following steps:

[0042] (1) Based on the analysis of historical failure data of components, the failure rate distribution function of a single component of a wind turbine is fitted using Weibull distribution.

[0043] According to the analysis of the historical failure data of the components, the shape parameter β and scale parameter α of the Weibull distribution corresponding to the historical failure data are fitted by function, and the failure rate distribution function of a single component of the wind turbine is fitted by Weibull distribution:

[0044]

[0045] In the formula, t refers to a certain time on the time axis as a variable.

[0046] The Weibull distribution is used to fit the failure rate distribution of components, which fully considers the change pattern of component failure over time. Compared with the traditional fixed time interval maintenance strategy, it can more accurately reflect the actual failure mode of the components and improve the scientificity and accuracy of the maintenance strategy.

[0047] (2) Introducing the age reduction factor m i and the failure rate increasing factor n i , calculate the relationship between the failure rate corresponding to the i-th preventive maintenance of a single component and the failure rate corresponding to the i+1-th preventive maintenance.

[0048] Introducing the age reduction factor m i and the failure rate increasing factor n i It is used to illustrate the phenomenon of service life regression and increased failure rate of mechanical parts after incomplete maintenance. The relationship between the failure rate corresponding to the i-th preventive maintenance of a single component and the failure rate corresponding to the i+1-th preventive maintenance is:

[0049] λ i+1 (t) = n i λ i (t+m i T i )t∈(0,T (i+1) ),

[0050] Where, T i Refers to the time point of the i-th maintenance, 0<m i <1, n i >1, service age reduction factor m i and the failure rate increasing factor n i The value of is usually determined empirically.

[0051] By introducing the age reduction factor m i and the failure rate increasing factor n i , which can quantify the impact of incomplete maintenance on the service life and failure rate of components, and then comprehensively consider the preventive maintenance cost, replacement cost and failure repair cost in the optimization process, seek to minimize the total maintenance cost, and maximize the economic benefits of maintenance.

[0052] (3) Based on the maintenance threshold R p , calculate the interval T of each preventive maintenance i .

[0053] When a single component of a wind turbine runs to a point where its reliability value is less than or equal to the set maintenance threshold R corresponding to incomplete maintenance, p When the fan is repaired, the reliability equation of a single component is:

[0054]

[0055] You can also write:

[0056]

[0057] In the formula, Represents the cumulative probability of failure during the i-th maintenance interval. When reliability is used as a constraint, the minimum number of maintenance times for a single component in each maintenance cycle is equal, and its value is -lnR p , so the interval T of each preventive maintenance can be calculated i .

[0058] (4) Calculate the maintenance cost E of the component per unit time, and use the optimization algorithm to calculate the optimal maintenance plan for the component during its life cycle, thereby determining the optimal number of preventive maintenance times N for the component.

[0059] Assuming that the number of incomplete maintenance methods used for a component within its operating cycle T is N, the maintenance cost E per unit time of the component is:

[0060]

[0061] Among them, C p is the component preventive maintenance cost, C t is the preventive replacement maintenance cost of components, C f is the component failure repair cost, C d is the maintenance cost per unit time of the component, and t is the time taken for different maintenance methods of the component; the component preventive maintenance model equation is as follows:

[0062]

[0063] The restrictions are as follows:

[0064]

[0065] R p >0,

[0066] N>0,

[0067] i=1,2,···,N,

[0068] T i >0,

[0069] The above formula can be used to solve the optimal preventive maintenance times N by the optimization algorithm. The optimization algorithm can use comprehensive optimization algorithms such as genetic algorithm, particle swarm algorithm, or develop an applicable algorithm. That is, the optimal maintenance plan of the component within the life cycle is calculated by the minimum value of the objective function E, thereby determining the optimal preventive maintenance times N of the component.

[0070] (5) After determining the optimal number of preventive maintenance times N, the maintenance process is simulated to obtain the maintenance interval and maintenance cost, and to evaluate whether it meets the needs of the wind farm. If it does, the decision parameters are determined; if it does not, the preventive maintenance strategy is adjusted and the parameters are re-optimized.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for decision-making on preventive maintenance interval of a single offshore wind power component, characterized in that: The following steps are involved: S1. Based on the analysis of historical failure data of components, the failure rate distribution function of a single component of a wind turbine is fitted using Weibull distribution; S2. Introduce the service age reduction factor m i and the failure rate increasing factor n i , calculate the relationship between the failure rate corresponding to the i-th preventive maintenance of a single component and the failure rate corresponding to the i+1-th preventive maintenance; S3. Based on the maintenance threshold R p , calculate the interval T of each preventive maintenance i ; S4. Calculate the maintenance cost E of the component per unit time, and calculate the optimal maintenance plan of the component within the life cycle through the optimization algorithm, so as to determine the optimal preventive maintenance times N of the component; S5. After determining the optimal number of preventive maintenance times N, simulate the maintenance process to obtain the maintenance interval and maintenance cost, and evaluate whether it meets the needs of the wind farm. If it does, determine the decision parameters. If it does not, adjust the preventive maintenance strategy and re-optimize the parameters.

2. A method for decision-making on preventive maintenance interval of a single offshore wind power component according to claim 1, characterized in that: In step S1, according to the analysis of the historical fault data of the component, the shape parameter β and the scale parameter α of the Weibull distribution corresponding to the historical fault data are fitted by function, and the failure rate distribution function of the single component of the wind turbine is fitted by using the Weibull distribution: In the formula, t refers to a certain time on the time axis as a variable.

3. A method for decision-making on preventive maintenance interval of a single offshore wind power component according to claim 2, characterized in that: In step S2, the relationship between the failure rate corresponding to the i-th preventive maintenance of a single component and the failure rate corresponding to the i+1-th preventive maintenance is: λ i+1 (t)=n i λ i (t+m i T i )t∈(0,T (i+1) ), Where, T i Refers to the time point of the i-th maintenance, 0<m i <1, n i >1, service age reduction factor m i and the failure rate increasing factor n i The value of is usually determined empirically.

4. A method for decision-making on preventive maintenance interval of a single offshore wind power component according to claim 3, characterized in that: In step S3, when the reliability value of a single component of the wind turbine generator set is less than or equal to the set maintenance threshold R corresponding to incomplete maintenance, p When the fan is repaired, the reliability equation of a single component is: You can also write: In the formula, Represents the cumulative probability of failure during the i-th maintenance interval. When reliability is used as a constraint, the minimum number of maintenance times for a single component in each maintenance cycle is equal, and its value is -lnR p , so the interval T of each preventive maintenance can be calculated i .

5. A method for decision-making on preventive maintenance interval of a single offshore wind power component according to claim 4, characterized in that: In step S4, it is stipulated that the number of times the incomplete maintenance method is adopted for the component within the operation cycle T is N, and the maintenance cost E of the component per unit time is: Among them, C p is the component preventive maintenance cost, C t is the preventive replacement maintenance cost of components, C f is the component failure repair cost, C d is the maintenance cost per unit time of the component, and t is the time taken for different maintenance methods of the component; the component preventive maintenance model equation is as follows: The restrictions are as follows: R p ＞0， N＞0， i=1,2,···,N, T i ＞0， The optimal maintenance plan for the component during its life cycle is calculated by minimizing the objective function E, thereby determining the optimal number of preventive maintenance times N for the component.

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