عنوان

Offshore Wind Farm Layout Optimization Using Mathematical Approaches and Heuristic Techniques

Number

TL55612

.Language of Text, Soundtrack etc

انگلیسی

Title Proper

Offshore Wind Farm Layout Optimization Using Mathematical Approaches and Heuristic Techniques

General Material Designation

[Thesis]

First Statement of Responsibility

Ülkü, İlayda

Subsequent Statement of Responsibility

Uslu, Çiğdem Alabaş

Name of Publisher, Distributor, etc.

Marmara Universitesi (Turkey)

Date of Publication, Distribution, etc.

2019

Text of Note

138 p.

Dissertation or thesis details and type of degree

Ph.D.

Body granting the degree

Marmara Universitesi (Turkey)

Text preceding or following the note

2019

Text of Note

Wind energy is firmly favoured worldwide as a renewable energy resource for electricity generation. Due to the climate impacts of offshore wind farms, the number and scale of offshore wind farms have been increasing. Design of a wind farm invokes several optimization problems. A wind farm, mainly, is composed of a set of turbines, one or transmitters and a set of electrical cable connections between turbines and transmitters. The problem considered in this thesis has three main parts: location of the turbines and connection of the located turbines that is cable layout design and a concurrent solution for both turbine location and cable layout problems. Determination of locations for each turbine within the wind farm is called turbine location (TL) problem. In the first part of the thesis, a novel nonlinear mathematical programming model for the layout of wind turbines considering the multiple wake effects is proposed. In the model two objective functions are taken into account separately: maximization of total power produced and minimization of cost for per unit of the power. Relative positions of turbines affect the amount of total energy generation because of wake effects. Jensen's wake decay model is used to involve multiple wake effects into the proposed model. It was experimentally proven that the solution space of the proposed model has the totally unimodularity property and relaxation of binary variables which show the wind turbine locations makes the model relatively easy to solve. Experimental study for the TL problem of the thesis exhibits that total power production and cost per unit of power generated from the developed model outperform that of the existing studies in the literature on a suit set of case problems and thus, can be employed to layout more productive and cost-effective wind farms. The determination of cable connections among turbines and transmitters to collect energies produced by turbines at one or more transmitters is called cable layout (CL) problem. In the second part of the thesis, cable connections between turbines and transmitter(s) are considered that is one of the challenging problems in the design of wind farm layout. This problem, called CL design, is especially important for offshore wind farms where the featured and highly costed cables are used. The second part of the thesis focuses on the optimization of cable connections of offshore wind farms to minimize the total cost of cables. The problem is modelled as a mixed integer linear program (MIP) respecting different cable types and capacities, non-crossing connections, and a limited number of total connections to a single transmitter depending on the transmitter type. Since CL design is an NP-hard problem, MIP model is modified by introducing additional heuristic rules, which are specific to the problem, to enhance the capability of MIP in solving of large offshore wind farms. An experimental study conducted on a suit set of test problems and real-life cases reveals that the proposed optimization models are able to find optimal or good feasible solutions within a reasonable amount of computer time compared to the previous studies in the literature. In the third part of the thesis, TL and CL are considered simultaneously. An integrated mathematical model, MIP_COMBINED, is developed for offshore wind farms to solve both wind TL and CL problems. MIP_COMBINED is a linear integer mathematical model for solving of wind TL and CL problems. A set of test instances were used to show the performance of the proposed model. Experiments showed that both linearizations of the objective function and binary variables of TL and CL problems caused MIP_COMBINED to have poor performance. Only three test cases out of twelve cases solved by the MIP_COMBINED. However, sequentially solving of TL and CL problems considering the power function in the TL part provided better cost-effective solutions compared to MIP_COMBINED model. Since the wind energy field of research has relatively great interest, solving the design problems takes an important part to generate new ideas. In this challenging context, the present thesis focuses on the optimal design of wind farm layout and of cable routing simultaneously.

Subject Term

Alternative energy

Subject Term

Environmental engineering

Subject Term

Industrial engineering

Ülkü, İlayda

Uslu, Çiğdem Alabaş

Marmara Universitesi (Turkey)

Electronic name

p

[Thesis]

276903

a

Y