Research On Operations And Maintenance Of Offshore Wind Farms

Offshore wind power is a crucial area of renewable energy industry. It is an important force to promote the wind power technology and the industrial upgrading, as well as a significant measure to facilitate the energy restructuring. China has rich offshore wind resource, so accelerating the construction of offshore wind power project is meaningful to the atmospheric haze governance in coastal areas and the transition of economic development patterns.In the dissertation, operations and maintenance of offshore wind farms are well studied.It starts from the maintenance scheduling problem, then the location-allocation problem of offshore base for supporting distant offshore wind farms, and finally the development of workboat, which is the most basic transportation of operations and maintenance. I propose several mathematical programming models for these problems in deterministic, fuzzy and random environments, and design corresponding algorithms for solving models effectively.Main contents and results of the dissertation are as follows:1. Research on the preventive maintenance scheduling of offshore wind farms. A multiobjective non-linear programming model is proposed in order to arrange the downtime caused by maintenance for all wind turbines. Two objectives are taken into consideration simultaneously. One is to maximize the system reliability and the other is to minimize the maintenance cost. The reliability criterion is newly defined by utilizing an attainment exponent which can be regarded as an expansion of previous definitions. I also design components of the maintenance cost criterion and constraints particularly applicable to the offshore wind farm environment. For solving the model, I employ the nondominated sorting genetic algorithm II and obtain a set of Pareto-optimal solutions for supporting the decision-making.2. Research on the location-allocation problem of offshore base. How to choose locations of offshore bases for distant offshore wind farms is considered when the transportation cost is minimized and fuzzy random demands of manpower and materials are satisfied.Utilizing the mean chance, three types of fuzzy random programming models, i.e., the expected cost minimization model, the α-cost minimization model and the chance maximization model are proposed to formulate the capacitated location-allocation problem of offshore base. In order to solve these models efficiently, I embed the network simplex algorithm and the fuzzy random simulation into the genetic algorithm to produce some hybrid intelligent algorithms.3. Research on the development of workboat. Using the quality function deployment for designing workboat for operations and maintenance, the customer requirements(CRs) of offshore wind power project can be transformed to the engineering characteristics(ECs)of the workboat. I present a fuzzy chance-constrained programming model with risk control to minimize the expected cost, for purpose of determining optimal target values of the ECs of the workboat. For solving the model, I integrate the fuzzy simulation and the genetic algorithm to design a hybrid intelligent algorithm.The dissertation studies on several optimization problems of operations and maintenance of offshore wind farms, trying to improve the situation of lacking in researches in this area. In the future, studies of offshore wind farms can be greatly expanded and deepened by multidisciplinary combination. Results can be applied to the industry for furthering fusion of science and economy and alleviating global energy crisis.