Subsea pipelines are critical for oil and gas production and transport, more than 100.000kmof subsea pipelines have been laid. These pipelines are laid by specially designed ships which can lay these pipelines at great depth and a high speed. However, designing the supply chain to deliver joints (pipe pieces) to these pipe lay vessels can be very complex; there aremany possible supply vessel combinations andweather influences that can impact the supply chain. This makes trying to find a good solution a very difficult and time-consuming process currently with a lot of manual iterations. This is called the Allseas problem. To solve this supply chain problema mathematical model is developed, thismodel can solve the supply chain problem while taking into account the many constraints. The research question that is discussed in this thesis is: Can the optimal usage of supply vessels, required to solve the pipelay vessel supply problem, be determined using a scenario based mathematical optimisation model? This model can eliminate the need for the many manual iterations and deliver an optimal solution that the Logistics and chartering department can use. To supply joints to the pipelay vessels several different types of supply vessels can be used. These supply vessels have different characteristics such as; hold capacity, sailing speed, capital- and operational expenditure, and workability (ability to work in bad weather). The supply vessels must supply joints to the pipelay vessel which can have one or two pipe transfer cranes. The number of pipe transfer cranes that can be used significantly influences the speed at which the supply vessels can be unloaded. A final important influence on the supply chain problemis the weather; specifically the wave height and wind speed: they determine if a supply vessel can unload it joints, or if the pipelay vessel can lay pipe. The goal of the problem is to design a fleet of supply vessels that can deliver the cheapest possible set of routes that will supply all the required joints to the pipelay vessel on time. A scenario based mathematical optimisation model is developed to find the solution to the Allseas problem. Some important parameters for this model that are thoroughly researched are: the desired stock level of the pipelay vessel, i.e. how full should the holds be? The demand window, i.e. how close to the demanded number of joints should the model deliver. The final parameter of interest is the node duration, all joints must be delivered during a certain time window the parameter node duration changes the size of the time window. The influence of these parameters is also investigated when weather is simulated. The results of the developed program show that it is possible to make a mathematical model that determines the optimal pipe supply vessel usage. Some other interesting parameters settings have also been found by the model. Allseas always tries to keep the pipelay vessels stocked as full as possible, however, the mathematical model has shown that it ismore advantageous to try to keep the vessel at 80%capacity sine the supply vessels can unload faster that way ensuring shorter routes. Furthermore, the mathematical model has shown that it can deliver cheaper solutions than are currently designed. This has been proven by comparing the results of the mathematical model with a project that Allseas has completed. The mathematical model presented a solution that was ¼ 10% cheaper than the solution Allseas implemented.

The modeling method for the performance of positive displacement pumps of hydraulic pumps is based on collecting operational data of the pump for its operational envelope and using equations with empirical fitting parameters and fit these equations to the data. This way values for the fitting parameters are obtained, with which the equations can be used as model for the operating performance of this specific pump. By implementing this modelling method no information about the contribution of each component present in the pump to the performance losses is obtained. A model which analyzes each coponent and estimates its contribution to the total power losses would be beneficial in the design of pumps. Therefore the answers to the following research questions are sought after in this work: - What are the components critical to performance within hydraulic pumps? - To what accuracy can a component-wise, analytical model for pump performance be created? - How sensitive to certain parameters used in the equations is the model? - What are the possibilities of implementing this model into pump design? After the pump system was analyzed and the internal interactions found, the components which effect pump performance the most were identified. These include bearings, rollers, seals, springs, valves and leakage flow which is dependent on gap size, piston movement and viscosity of the hydraulic fluid. For these components analytical equations are presented which are incorporated in the model. The accuracy of the model is tested by comparing its results to test data of an experimental camring driven radial piston pump. The model predicts leakage flow to an average difference of 3% relative to the data, but outliers up to 49% for high pressures and -35% for low pressures are observed. Input torque is predicted to an average difference of -19% relative to the data. This difference is mainly caused by the inaccuracy of the predictions below 30 bar operating condition, where outliers up to -61% are observed. These results are compared to an empiric modelling method and are found to be more accurate for leakage flow for the entire operational envelope, yet on average less accurate for input torque. The sensitivity of the model to certain parameters is tested. The parameters investigated are the rolling resistance coefficient of rollers and bearings, bearing lubricant viscosity, hydraulic fluid temperature, piston-cylinder alignment and the corresponding forces resisting piston motion and the assumption of laminar leakage flow. To show the possibilities of the model in pump design the rollers and appurtenant bearings present in the pump are replaced with hydrostatic bearings. The design is discussed and a hydrostatic bearing with an orifice restrictor is designed of which implementation will approximate the total efficiency of the pump with rollers. The Reynolds number of the flow necessary is found to be too high for capillary restrictors. To approximate the same total efficiency for each operating condition the average bearing flow is found to be 0.0016 L/s, which corresponds to an average fluid film height of 12 μm. The orifice restrictor diameter which allows this flow is found to equal 0.24 mm. This work shows the possibilities of such a model, yet there is plenty room for improvement of the accuracy of the predictions made. Recommendations to this end are given in the conclusion and recommendations of the report.

The first large offshore wind farms installed in the North Sea Region (NSR) soon reach their technical end of lifetime. The wind turbines in these farms will have to be decommissioned after power production has stopped. Currently offshore wind turbines are decommissioned based on a method called reversed installation, a time consuming and therefore costly operation. This report focuses on the situation regarding decommissioning of offshore wind turbines (excluding foundations), and unveils the possibilities of potential decommissioning methods, using a jack-up, in an effort of to obtain a more cost-effective and environmentally friendly method than the currently used reversed installation. The act of decommissioning is explained, together with the expected market of decommissioning in the North Sea Region. Legislation concerning decommissioning of the five largest offshore wind producing countries in Europe are discussed. Using a multi criteria analysis on demolition methods, floating alternatives, and a model (determining the transport configuration), the most economical and least energy consuming combination is chosen. This model shows an economization of up to 66% and cutting the energy consumption by a third. Lastly, these outcomes are applied to three separate business cases including a sensitivity analysis to show the effect that variations in input values have on the results.

Due to the growing demand for offshore wind energy and the increasing wind turbine sizes, a shortage of capable installation vessels is anticipated by 2024. Consequently, the utilisation of heavy-lift vessels, previously not employed for bottom-founded or floating offshore wind turbine installations, may become imperative to realise the offshore wind project pipeline. Therefore, this study analyses the technical and economic feasibility of installing floating wind turbines with the largest construction vessel in the world named the Pioneering Spirit. For this, the concept development stage of the systems engineering method was applied, consisting of three successive phases. Firstly, in the Needs Analysis phase, valuable insights regarding the operational environment were obtained, resulting in operational requirements for the concept design. Secondly, in the Concept Exploration phase, these requirements were used for generating multiple alternative concept options after which the most promising concepts were selected for further analysis through a trade-off analysis. Lastly, in the Concept Definition phase, the technical feasibility, workability and economic feasibility were evaluated for the selected concepts. The technical feasibility was assessed by creating storyboards for the different installation procedures, determining the stability of the barge named the Iron Lady for different load cases and providing technical descriptions of performed operations and required equipment. Furthermore, the workability was estimated by comparing statistical wave and wind data with the environmental limits for various operations obtained through literature, previous projects and a motion analysis model. Subsequently, with the storyboards and workability results, the economic feasibility was determined with a model that included estimations of the vessel and fuel costs for constructing a reference wind farm located at a variable distance to shore. Ultimately, it was found that Spar- and TLP-type floating wind turbines are of most interest for the concept design and that the Pioneering Spirit is in principle capable of installing the corresponding pre-assembled foundations and wind turbines relating to a capacity of 15 megawatt with a single-lift operation. Furthermore, this research gives valuable insights that extend beyond the initial scope of this paper. Since the performance implications of the selected concepts related to the workability assessment and economic feasibility study can directly be linked to specific design choices and limitations. This, in combination with the exploration of floating wind turbine installation with alternative lifting equipment, can be used to provide recommendations for future designs of purpose-built vessels in this sector. Finally, the methodology used in this study could be applied to evaluate the feasibility of other potential concepts for deployment in this area.

As a result of the need for higher productivity ship-to-shore container cranes, seven concepts are composed that can simultaneously transfer 4 Twenty Foot Equivalent Unit containers. All concept can be built on a standard ship-to-shore crane structure. These concepts are based on working principles found in (patent) literature. The concepts are compared based on multiple objectives, after which one concept is chosen to realize a concept design. A ship-to-shore crane with two trolleys turns out to be the most suitable concept. The two trolleys consist of a rope towed trolley and a semi rope trolley, which are combined with a continuous rope support system. The design of the trolleys is based on an existing trolley. For all wire ropes to run adjacently, the sheave diameters and positions on both trolleys deviate from the existing trolley. The sheave positions have consequences for the trolley frame design. To validate the adjusted trolley frames, a finite element analysis is performed.

Due to the global climate change there is a increasing demand for transportation on renewable fuels. An increasing trend in electric propulsion can already be seen in the automotive industry and this is now also gaining popularity in the maritime sector. Due to limited capacity if the onboard battery, especially electric ferries are becoming more popular, because of the relative short sailing distances. The first electric ferry became operational in 2015 in Norway and since than a hand full of electric vessels was developed. An electric vessel requires a charging mechanism to charge while unloading and loading passengers in the port. Besides, generally also a mooring mechanism is necessary. This enables the vessel to turn off the propeller while charging which limits the energy demand while charging. Various systems have been developed already. However, these are not standardized solutions but all one of a kind systems designed for a specific vessel or fleet. Which of these is the best solution is not easy to determine and strongly depends on the vessel characteristics and the operating environment. To supply the expected increasing demand for electric vessels, a guideline is developed which will help the engineer to find a suitable charging and mooring mechanism and to decrease the selection time for this system. The will provide Damen a strategic advantage towards other shipyards in vessel tenders since both the development costs and delivery time is lower. This guideline is developed based on the knowledge gained during a case study for a 81m Ropax ferry, sailing in the surroundings of Vancouver Island. For the case study an engineering design method was selected from literature and applied to this case, for which Damen had a hard time finding a charging and mooring mechanism. First thought was to combine both into one mechanism, but this is difficult due to conflicting functionalities of both systems. Due to the limited time available for the research, the design of the mooring mechanism is not taken into account for the case study. Setting the requirements for the charging mechanism is complex due to the range of different fields of interest that should be taken into account. However, the requirements of these various aspects are often related in some way to one another. This makes it easy to lose sight of the structure of all requirements. Comparing the functions that the charging mechanism should fulfill within these requirements and the existing charging mechanisms, it can be concluded that no suitable system is available yet. The gap between these is defined as a set of three functions; to compensate the tidal difference, deal with misalignments between the vessel and the shore and to provide flexibility for vessel motions. A new design was made which covers this gap. Additional research was done to ensure sufficient flexibility from the power cable, since this proved to be critical in the state of the art systems. From the knowledge gained during this case study, the guideline is developed. The guideline provides insight in the influential factors while selecting an mechanism. This should offer the engineer a structure to set the requirements and ensures that no aspect is left out of the requirements. An overview with the already existing mechanisms is provided which should be consulted multiple times during the process, to check whether a suitable systems exist, if the requirements should are too tight or if the project is not profitable at all. The structure of the requirements is designed such, that the relative easy requirements are set first. This prevents from doing demanding calculations or going on expensive business trips, while it could have been seen earlier that a project is not feasible or profitable at least. The guideline is validated while selecting a charging mechanism for a different type of vessel. This validation proved to decrease the selection time for a charging mechanism significantly compared to previous projects within Damen. After the test, a charging system was found which is preferred for the vessel. This charger is now further discussed with the supplier of the system.

Due to more stringent greenhouse gas (GHG) emission regulations in the maritime industry, solutions are being sought to decrease the GHG emissions of crew transfer vessels used in offshore wind farms. Multiple alternative fuels and power generating systems can be used to decrease these emissions. In this research, a comparative study is performed on six concept solutions. Four fuel types (hydrogen, HVO, methanol, and renewable energy) and three different power generating system components (proton exchange membrane fuel cells, lithiumion batteries, and internal combustion engines) are considered. The option of charging a battery-powered ship offshore is also considered. The goal of this research is to identify the most cost-effective system to reduce GHG emissions. The comparison is based on the total cost of ownership, the GHG emissions of fuel production and utilisation, and the GHG emissions of the production of the power generating system. In order to achieve this, the component sizes and lifetimes are calculated based on the constraints of the ship and the operational profile with different transit distances to the wind farm. The lifetime of the fuel cell is based on a cell voltage degradation model developed in this research. A battery electric ship with a methanol genset is found to be the best method with the largest GHG emissions reductions in relation to cost. Without charging offshore for a transit distance up to 18 km, and with offshore charging beyond 18 km. If charging offshore is not considered viable, a combustion engine with hydrogen is the best option for a transit distance of 18 km up to 68 km, and HVO upwards of 68 km.

Dynamic pricing can be used for better fleet distribution in free-floating vehicle sharing (FFVS), and thus increase utilization and revenue for the provider by reducing the supply-demand asymmetry. Supply-demand asymmetry refers to the existence of an undersupply of vehicles at some locations at the same time as underutilization of vehicles at other locations. We propose to use dynamic pricing as an instrument to incentivize users to rebalance these vehicles from low demand locations to high demand locations. Despite significant research in rebalancing vehicle sharing, literature so far lacks experimental results on dynamic pricing in free-floating vehicle sharing. We propose to use an algorithm that minimizes the differences in the idle time of vehicles. The algorithm is tested in a real-life experiment that was conducted in cooperation with an FFVS provider. The experiment shows that even slight dierences in pricing and a novice algorithm can already influence user-behavior to counter the supply-demand asymmetry. Improving the existing algorithm by doing more experimental research is advised to further uncover the potential of this strategy.

As liquid bulk vessels are berthed in ports, auxiliary engines generate the electrical power demand, which emissions have a negative effect on the environment and local air quality in ports. Shore power is an effective solution for this problem. However, the large costs of implementing shore power and the absence of a technical safe design standard led to no adaption of shore power. Currently, there are no insights in the costs and utilisation of shore power in the liquid bulk industry. This thesis used an adapted systems engineering approach for a framework with a technical background and shore power concept evaluation. The shore power evaluation on costs and power utilisation combines the Life Cycle Costs approach and operational tanker data. By designing a model that evaluates the costs and utilisation for terminal and ships, insights for the business case for shore power have been obtained. Shore power implementation is extremely sensitive to utilisation, if the shore power readiness of ships is low at the terminal, it will be economically unfeasible. As well as for the ships, if no ports with shore power can be visited, shore power is not at all costeffective. The chemical shortsea market has the most potential for shore power implementation, due to the frequent visits of ports in Europe. This thesis has found that shore power can be economically feasible when European shortsea shipping is implemented in EU ETS with a CO2 price. The required CO2 price ranges from 33 to 84 €/ton depending on either 100% to 50% of shore power visits of the vessels, respectively. The terminals are unable to provide low shore power prices with only the vessel utilisation, therefore subsidy ranging from 25 to 100% is required on the investment, depending on the terminal. The emission reduction potential of shore power is good, with no local emissions in ports and the power generation emission reduction of 80 to 90% per pollutant. Currently, shore power for the chemical industry is not economically feasible but provides a good emission performance in the port. For all evaluated shore power systems, EU ETS CO2 prices are required for shipping and subsidies for the terminal investment. The best performing shore power concept on based on technical, economical and utilisation feasibility is the aftship based shore crane and reel, resulting in the best costeffectiveness. In order to introduce shore power to the liquid bulk market, CO2 prices on shipping of at least 50 €/ton is required and subsidies of at least 50% of the investment for terminals are required.

In the field of vibration energy harvesting, vibration energy is tranduced to electrical energy to power small, low powered devices. Many energy harvesters are produced in the form of a resonator, where resonant amplification enables efficient operation of the energy harvester. At low frequencies below 10 hz, input motions quickly increase for a constant input acceleration and resonant amplification results in energy harvesters that are too large to implement them. A solution is sought in creating a nonresonant energy harvester. The stiffness of a strongly coupled piezoelectric beam is compensated by adding negative stiffness to bring it to a near statically balanced state. This negative stiffness is embodied by attracting magnets. To model the dynamics and voltage output of the harvester, a modal analysis based distributed parameter model is used and further developed by including negative stiffness and force-displacement measurements of the stiffness compensated piezo. To investigate the mechanical behaviour of a compensated piezo, force-displacement measurements are carried out at different deformation speeds and load resistances. From these measurements, it has been observed that the stiffness of the compensated piezo strongly depends on the connected load resistance and the deformation speed. Furthermore, memory effects in piezoelectric hysteresis found in actuators such as curve alignment and wipeout have also been confirmed in force-displacement measurements. The performance of the harvester has been evaluated by exciting it on a linear air bearing stage. It has been found that for excitations between 2 and 6 hz, the error in RMS power between simulation and measurement remains below 10%. For its range of excitation, this harvester has been observed to be the most efficient with respect to prior art from literature. Therefore, stiffness compensation of a piezoelectric energy harvester can be considered as a successful method to improve the efficiency at low frequency excitation.

This paper proposes an online motor-parameter-estimator for a PMSM in an EV-powertrain. The proposed method differs from the conventional approach by using thermal measurements to decouple the resistance estimation from the rest of the estimation. Conventional approaches use the voltage and current measurements to estimate all parameters at once. However the resistance estimation was often found to be unreliable and noisy due to the low-contribution in the voltage-equations. A recursive least-squares filter approach in combination with the discrete-time dynamic voltage-equations was adopted. In this way the estimator was valid in both transient and steady-state operation while providing a robust estimation over the entire operating range. The proposed estimator was validated both using simulations and experimentally. A sensitivity analysis showed the proposed estimation approach is more robust against rotor-position error leading to smaller errors in the estimation. In the experimental validation the proposed estimator showed reliable estimation over the entire operating-range of the PMSM whereas for the conventional method the unreliable resistance, caused estimation error on the other parameters. The proposed method can be adopted for online maximum-torque-per-ampere control and adaptive-torque-control in an EV-powertrain.

The urgent development of green energy has become a worldwide trend in the war against the threat of global warming and the impact of extreme weather. The offshore wind farm is one of the solutions that are able to harvest energy sustainably from the environment. To erect these offshore windfarms, the debate about whether a new fleet should be designed and built or make the existed offshore fleet go under retrofitting has been raised. The stakeholder group involved in this issue is formed by the ship designers, ship operators, and market analysts. The difference between the existed offshore support vessel fleet and the offshore wind farm support fleet is the former is built to perform a certain operation and will require another considerable investment to be retrofitted while the latter is looking for solutions to switch from different equipment thus to keep the flexibility between different operation. The main objective of this research is to propose a ship design methodology to enable the offshore wind farm's request in mission flexibility by improving the design process in the preliminary design phase. Modularity and Knowledge Based Engineering (KBE) are chosen to be the two main topics to support the research objective. To narrow down the research scope, the research object is limited to a small Offshore support Vessel fleet that is able to perform service throughout the lifecycle of an offshore windfarm. The application of the modularity concept is to break down the vessel system into smaller subsystem or function blocks then reassemble them to be self-sufficient modules. Modules are the basic elements for forming a modular platform to provide a basic model that is able to perform various operations by mounting different equipment. In the former research done in NTNU, a methodology for manipulating the modularity to assemble a product platform by processing previous configuration scripts has been developed. It has greatly reduced the repetitive and iterative works in the design of similar vessels, especially the design for OSVs. Though the configuration scenarios are flexible to change, the pre-designed modules' properties are limited by the based configuration. On the other hand, the configurations are closely tight to the hull shape thus limited the freedom from both the hull design and configuration design. In this research, an improved configuration generator is developed to separate the configuration design and the hull design. The proposed methodology will also keep the flexibility in importing new configurations and the latest hull shapes without conflicts. Knowledge based engineering is another topic included in this research. It has been proved and widely used in the aerospace industry. As for the ship design industry, the application is limited to local structure design. KBE is a bridge to bring the user and the designer together in the design project. It consists of a programming stage, Knowledge Based System (KBS), to process the selection of suitable design cases and a visualization stage, Computer-Aided Design (CAD) ,to give a direct review on the whole design project. The fundamental drivers for each KBE system are called "High Level Primitive" (HLP). They are the basic units for the knowledge stored in the database. KBS picks out suitable HLPs from the database and assigned them in a configuration script thus forming a design result stored in the digital world. CAD will take over the result and visualize it in the drawing window. This is the proposed methodology to fill the gap between the modularity re-configuration and the diversity of modules. A Multi-Model-Generator (MMG) will become the final output of this research. It is designed to be able to reproduce several vessels in the OSV market. A further demonstration of the ability to generate a modular OSV product family at the end of the research. Though the modeling output has been proved to meet the index set for the research object, the MMG has the potential to be improved in the future by importing a well-constructed database from the industry.

Climate change due to greenhouse gas emissions is prompting the IMO to reduce emissions by 80% by 2050. This thesis focuses on designing modular propulsion systems for mid-speed sailing vessels to meet these regulations. It designs a framework to generate and swiftly evaluate propulsion system designs on the basis of five performance indicators: Weight, Volume, Life Cycle Costing, Modularity and Emissions. Additionally, the framework is proven on the basis of a case study, which results in a modular concept.

This bachelor thesis is written as part of the curriculum for the bachelor Electrical Engineering at the Delft University of Technology. The thesis is part of the course EE3L11 - Bachelor Afstudeer Project and took place from April 2017 until July 2017. This document describes the development of a system that is able to drive electric drum brakes, the brake control unit (BCU). The BCU is a subsystem of a larger project; a braking system that minimizes the force between a trailer and a car when braking. The ultimate goal is to let the trailer completely brake for itself. To achieve this, two other subgroups have designed a control algorithm and a force sensor readout circuit that measures the force. The BCU receives a desired braking force from the control algorithm that should be exerted in order to eliminate the force between car and trailer. This input force covers a certain range, so the BCU should be designed such that the braking force of the brakes can be regulated. For this purpose a power supply, current controller and lookup table are designed. The developed power supply is able to provide a constant voltage to the solenoids inside the electric brakes. The power supply consists of a DC/DC converter, which is powered from a car battery. As a consequence, the input voltage of the DC/DC converter is dependent on the state of charge of the battery. Nevertheless, the output of the designed converter is able to provide a constant DC voltage with a maximum current of 8 A. The designed current controller makes use of a PWM driven current source, which controls the output current of the DC/DC converter. Besides this source, an algorithm that estimates the duty cycle of the PWM signal is derived, based on the desired current through the solenoid. Last, a lookup table is implemented that determines which current is needed for specific input forces. The table makes use of inter- and extrapolation between measured test results to calculate the right current for every input force.

The development of renewable energy applications has become increasingly important in the past couple of years due to a growing global energy demand and increasing consciousness of global warming. A recent development in renewable energy is the application of offshore floating solar systems. A prototype design for this application, as developed by the company ’Oceans of Energy’, consists of multiple floating platforms (floaters), moored to the sea bed. One of the challenges for offshore floating solar systems is the continuous wave induced force acting on the floater that can become significant in severe weather conditions. Numerical simulations are often used to analyse and predict these forces. Combined frequency-time domain solvers are the most promising tool for this design to obtain reliable results within reasonable computational time. However, it is unknown what the capabilities of this solver is for the novel offshore floating solar system. The goal of this study is therefore to determine to what extend the frequency-time domain solver is able to accurately simulate the behavior of the multi-body, offshore floating solar system. A numerical model was developed in the simulation tool ’aNySIM’. Experiments conducted in the offshore basin at MARIN were used for the model structure development and validation. Additionally, viscous damping effects were implemented from empirical data based on the experiments. Decay tests were used for damping determination. This resulted in inaccurately determined forces and motion amplitudes for regular and irregular wave tests. A new damping determination method was introduced, using regular wave results as input. The accuracy of the model improved with 4% using this method. Nonetheless, inaccuracies in mooring line forces, oscillating behaviour and motion amplitudes are present. These inaccuracies have been addressed with an uncertainty analysis and sensitivity studies. Trends within the accuracy of the simulation model were linked to physical phenomena that occurred during the experiments. Analysis showed that several effects, related to the novel design characteristics, influence the model accuracy. Multi-body (e.g. shielding of floaters) and mooring system aspects (e.g. hydrodynamic loads on mooring lines) have been identified, influencing the viscous damping of the system. Additionally, nonlinear effects due to, amongst others, breaking waves have been identified. For regular wave tests and lower irregular wave tests, the simulation model gives reliable results with errors in the mooring line forces below 10%. These errors are mainly ascribed to viscous damping effects. For higher sea states the simulation behaviour shows discrepancies and errors in the mooring line forces increase. In these tests, nonlinear effects due to breaking waves become more relevant. For future work, different uncertainty causes must be further isolated in the simulation model. This can be done by obtaining more experimental data. To quantify the effects, studies in other numerical tools can be performed (e.g. CFD calculations) and more extended sensitivity studies must be executed in aNySIM. We present a structured

When your dream yacht is being built at Feadship, the process starts with a blank page. This early stage is defined as the Sales phase. In consultation with a designer, the look and the feel of a yacht is easily captured. The expertise of the designer will lead to a yacht fitting the vision of the client. In the current process, the lines drawn on paper restrict the design freedom of the naval architect. Next, not all consequences of decisions are known, which leads to the probability of alterations in later phases. The current design method is called a point-based method. A single starting point is chosen, which is gradually refined in a couple of iterations. This method has some disadvantages. Design exploration is a method in which many solutions are generated in a design space and no single starting point is chosen. The main focus of this approach is to postpone the design decisions until they can be made with the required knowledge. This will prevent alterations and rework in future phases. In this research, there is investigated whether design exploration could be implemented in the Sales phase at Feadship, using design drivers for the exploration method. The design driver origin from the stakeholders (client, regulatory bodies and Feadship) and are used to structure the design requirements and to evaluate the solutions. Creating the design space is done with help of a simple Design Model. Due to the limitations of the Sales phase this model is built with help of regression lines, empirical formulas and rules of thumb. The set of solutions are explored with eight design drivers which originated from the stakeholders and Sales process: Aesthetics, Usage, Performance, Rules, Costs, Space, Comfort and Safety. The design drivers are categorised into three parts: input, constraint and output. The input will follow from the client, where the constraints will follow from the other two stakeholders. The final choice for the output is made by the client, which can be underpinned with help of the output design drivers. This research concludes that design exploration could be an improvement on the current used point-base design method. Since design exploration fully utilises the design freedom available in the early stage design. The solutions produced by the Design Model show reasonable results, which lie within a 10% margin of the existing designs. Due to the limitations of the Sales phase the choice was made to use regression lines. As a result, the design space consists of solutions of which the trend is clearly visible. Nevertheless, the variety within the design space is sufficient enough to create a diversity in solutions. The results produced by the Design Model will be a good starting point in the starting phase. In order to use the results as more than a starting point, the detail level of the calculation methods should be improved. Generating a set of solutions will enable the designer and client to make well-informed decisions. Especially when the client is involved in this process.

The Dutch government has set out to largely reach reductions in carbon emissions in the electricity sector with the utilization of offshore wind energy. Due to the intermittency of wind energy this poses new problems and challenges for the future electricity system in the Netherlands. The objective of this report is to identify the challenges for the electricity supply of offshore wind farms and to research how energy storage and alternative wind turbine design can aid in these challenges. The problems experienced and possible solutions are first identified by conducting a literature review and data analysis. Subsequently a Matlab model is constructed to simulate an offshore wind farm and energy storage system. This model is used to determine the most cost-efficient storage technique and the impact of this technique on the future electricity system. Of the challenges for future offshore wind farms do the short-term profile effects have the most influence. These effects negatively affect: 1. the security of supply in the electricity system, 2. the stability of the load on the high voltage grid and 3. the market value of the produced electricity. The impact of these effects is intensified by the strong correlation in power production between the connected (future) onshore and offshore wind farms. To reduce profile effects energy storage is used, the optimal configuration of the storage system has a power capacity between 0.23 and 0.27 times the rated power of the wind farm. For the optimal energy capacity, however, no optimum is found, and the design depends on the desired impact of the system. An analysis on the impact of an optimal design has shown that an offshore wind and energy storage system does not result in an economical feasible system. Short-term profile effect reduction with energy storage, however, is shown to be essential in a future electricity system that is dominated by wind and solar power. The short-term profile effects of wind energy production are correlated too much and will have a too high impact on the system if no energy storage is included in offshore wind electricity production.

Increasing emissions have led to the search for alternate power systems to provide energy for maritime applications. The recent drop in battery prices (over 200 % in the last ten years) has made battery energy storage one of the practical alternatives for fossil fuels to curb emissions and reduce the carbon footprint of the maritime sector. The main criterion for choosing a ship’s battery system is its operational profile. Therefore, this study estimated and studied the operational profiles of three use cases - Superyacht, Bulk Carrier and Ferry. The information about the power requirements for ship activities was obtained from the operational profile. Based on that information, different strategies were presented to implement battery energy storage for each use case. A rule-based controller was developed to simulate the power split between the IC engines and battery packs for hybrid systems. Battery packs were sized according to the batteries’ energy consumption, which was found using the design criteria for each use case. A State of Charge (SOC) estimation model based on Coulomb Counting was developed to study the load cycles of the batteries. The SOC profiles were estimated for the proposed battery-powered systems and then characterised for each use case. Finally, a comparison between the conventional power system and the proposed battery power systems was made based on fuel consumption and greenhouse gas (GHG) emissions.

Ambitions to limit climate change are incentivizing the expansion of renewable energy. In particular, offshore wind energy is expected to grow rapidly. To harness the full potential of existing as well as prospected offshore wind farms, the limited capacity of the internal cable network of the offshore wind farm, called the collector system, should be efficiently used. The operation of the collector system during cable outages presents significant potential in this regard. Currently, during these outages, a conservative approach is taken that under-utilizes the capacity of the collector system and consequently limits power production excessively. The available headroom of the system can be unlocked by optimizing the power routing and turbine setpoints. This optimization problem is the topic of the MSc Thesis, carried out within Vattenfall. Two novel optimization-based rerouting and setpoint decision frameworks are developed for collector systems with arbitrary topologies: an open-loop control strategy and a receding horizon control strategy. The open-loop control strategy assumes that the network can only be reconfigured at the beginning of the outage. It is formulated as a mixed-integer linear programming problem, in which the cables are modeled as binary control variables and the setpoints as continuous control variables. The receding horizon control strategy is deployed in real time, leveraging cable temperature measurements and power forecasts to derive optimal control actions dynamically. Dynamic thermal rating is applied, which entails that the power flows are constrained based on the cables’ temperatures rather than on a static rating. The resulting control strategy is formulated as a mixed-integer quadratically constrained programming problem. A case study is performed to compare the performance of the developed strategies to existing strategies. Simulations concerning seven occurred cable outages at an offshore wind farm show an average increase in power production with respect to the industry control strategy of 0.82% for the open-loop control strategy and 4.2% for the receding horizon control strategy.

AGVs have seen an upward trend in development over the last 60 years. The technology has developed from mechanical bumpers and guided wire navigation to contactless sensors and free navigation technique in the current age. Further, the control on AGVs has moved from central control system to local intelligence which opens up various possibilities with respect to operations as well as applications. The growing trend of AGVs has been due to the sudden growth in digital technology and the ever-increasing demand to reduce human intervention in operations. This has resulted in increased research regarding the implementation of intelligent AGVs in areas of application that have not yet been explored, namely, light metal and forging industry. The major reasons for indulging in autonomous equipment are, increased productivity, reliability and safety since human involvement is either eliminated or largely reduced. However, a major share of the research about intelligent AGVs has been confined to warehouses and port logistics. Therefore, through this research, another area of application is investigated, namely, the light metal and forging industry, and more specifically, the potroom of an aluminium smelter. Hence, the objective of the research is as stated: With the introduction of intelligent AGVs, stochastic behavior needs to be addressed, that is, how would these AGVs react to disturbances created by such random human behaviour and process interference? Therefore, the research focusses on the routing problem in such situations which are dynamic in nature. The research aims to provide a planning approach in terms of dynamic AGV routing under the assistance of a sensor based system that can detect obstacles. The dynamic re-routing of AGVs is addressed using a mathematical formulation as well as a graphical representation. In order to solve the problem at hand, the graphical approach is followed and the objective has been simplified for research purposes. It is simplified as: For instance, if a certain pathway is blocked in the potroom of an aluminium smelter due to such stochastic behavior, how would the AGV find the optimal path? An algorithm is devised in order to answer the above research question and further implemented in Python. Various scenarios of stochastic disturbances is analysed and evaluated accordingly. Therefore, this research develops an algorithm and a subsequent model that is implemented using Python which is used to evaluate the routing of an AGV in the presence of stochastic behavior. It acts as a proof of concept for the problem at hand as it restricts the work to a simplified situation of a single AGV operation. Although this research uses the case of a light metal and forging industry, the same can be applied to industries with similar challenges such as, cement industry, power generation industry, aerospace, construction and so on. Cement, construction and power generation industry deal with environments similar to the light metal and forging industry. Further, in all these application areas, the use of AGVs for material handling would improve productivity and reliability, while improving safety of operations as well. This research focuses on a simplified situation, however, the basis of this work can be further extended to solve a more detailed real world scenario with a fleet of AGVs, and this can be done by the use of advanced heuristics.