Irina Dolguntseva Temiz

• PhD
• Uppsala University

Full text available: https://ieeexplore.ieee.org/document/10915853

As the world transitions toward renewable electrification to reduce CO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> emissions, remote island electrification remains a challenge. While some islands are grid-connected, many still rely on fossil fuels for electricity generation. Several studies...

Ocean waves have the potential to contribute to future renewable electricity production. A wave energy converter (WEC) is a technology developed to absorb the energy of the wave and convert it to another form of energy. The Uppsala University WEC (UU WEC) is a point absorber with a direct drive permanent magnet synchronous linear generator power ta...

The electrification of remote islands has long been a subject of research interest, primarily because of their historical reliance on fossil fuels, leading to a significant carbon footprint. Recent advancements in wave energy converters offer a promising avenue to make these islands more self‐sustainable while considerably reducing carbon emissions...

The development of wave energy technology has advanced significantly, and its grid connection and power optimization stages have been an area of research. Various grid connection schemes have been thoroughly researched and are being implemented, while grid-following control has emerged as the primary technique for power transfer to the grid. Energy...

Wave energy has been an immense area of interest in research and industry in our move towards a sustainable energy production society due to its high energy density and surface area. However, the grid connection of wave energy converters is still one of the major challenges due to the complexity of varying wave resources (amplitude and frequency)....

The paper investigates the added grid value of co-locating wave energy converters with offshore wind turbine generators and floating photovoltaic solar panels. Grid value is evaluated in terms of power generation variability and electrical infrastructure utilization. Using meteorological reanalysis data for the region of the North Sea, wave, solar...

In this contribution, a novel combination of the basic principles of Genetic Programming and Genetic Algorithm for grid integration of purely offshore multi-source parks (OFPV/Wind/Wave) is proposed. The main contributions of the undertaken simulation model are reduced power losses at the PCC and steady seasonal variability of the combined capacity...

Decarbonization of ports is a major goal to reduce their global carbon footprint. The port of Hvide Sande is located on the coast of the North Sea in Denmark and it has the potential to utilize various renewable energy sources. Wind and solar thermal parks are already installed there. Wave energy is an alternative to solar and wind energies and its...

This paper proposes and analyzes a genetic algorithm based permutation control logic applied to the aggregator of an offshore multi-source park. The energy losses at the common coupling point are accounted for in the feedback. This paper focuses on offshore distributed energy resources, such as floating photovoltaic (PV), wind, and wave power. The...

Wave energy is one of the emerging sustainable energy resources due to its high energy density and vast untapped areas. Nevertheless, the intermittency of wave resources is a significant challenge for the grid operator. Additionally, a varying grid demand is an added complexity to wave resources. Energy storage systems such as batteries and superca...

Marine energy resources could be crucial in meeting the increased demand for clean electricity. To enable the use of marine energy resources, developing efficient and durable offshore electrical systems is vital. Currently, there are no large-scale commercial projects with marine energy resources, and the question of how to design such electrical s...

Abstract Analytical solutions and estimations for the power flow in the air gap of linear electrical machines of different geometries are derived from Poynting's theorem. The different geometries considered are flat one‐sided, multi‐sided, and tubular linear electrical machines. The radial power flow for all considered geometries is dependent on th...

Two different concepts of wave energy converter coupled to the novel C-GEN linear generator have been studied numerically, including the evaluation of different buoy sizes. The first concept has a slack connection between the buoy and the generator on the seabed. Another concept is based on a stiff connection between the buoy and the generator plac...

The present paper considers pitching wave energy converters (WECs) integrated in a floating platform, e.g., floating foundation for a wind turbine. Each WEC consists of a partially submerged wave absorber that rotates about the hinge located above the still water level under the influence of waves. Each wave absorber contains separated ballast tank...

The wave power potential in the North Sea was studied in several publications for different locations. This paper estimates the wave power potential at a specific location, namely, near the town of Hvide Sande, located on the western coast of Denmark. To assess the wave energy resource at Hvide Sande, a hindcast model utilizing SWAN (Simulating WAv...

The vast energy found in the ocean can be captured and converted to electricity using wave energy converters (WECs). For that purpose, different designs of WECs have been manufactured and tested offshore globally , despite the high installation, maintenance, and decom-missioning costs. However, one of the important factors hindering the wide develo...

Abstract Power fluctuations induced by wave energy converters (WECs) may reflect negative impact on the power quality of the power grid. Assessing their impact is an important step to ensure the grid compliance level of the energy park. The IEC 61000‐4‐15 standard classifies the allowable disturbances in the grid. This study analysed and assessed t...

Wave energy converters (WECs), which are designed to harvest ocean wave energy, have recently been improved by the installation of numerous conversion mechanisms; however, it is still difficult to find an appropriate method that can compromise between strong environmental impact and robust performance by transforming irregular wave energy into stab...

Wave energy is of interest for regions with high wave power potential, as well as for regions with modest wave power potential such as the Adriatic/Mediterranean coastlines and islands. In the present paper, the possibility of integrating a wave power farm with the power system of an island in the Adriatic Sea, combining the wave power with a batte...

Absorbing wave power from oceans for producing a usable form of energy represents an attractive challenge, which for the most part concerns the development and integration, in a wave energy device, of a reliable, efficient and cost-effective power take-off mechanism. During the various stages of progress, for assessing a wave energy device, it is c...

The aim of wave energy converters (WECs) is to harvest the energy from the ocean waves and convert into electricity. Optimizing the generator output is a vital point of research. A WEC behaves as a nonlinear system in real ocean waves and a control that approximates the behaviour of the system is required. In order to predict the behaviour of WEC,...

Wave energy converters (WECs) have been deployed onshore, nearshore, and offshore to convert ocean wave movement into electricity. The exploitation of renewable energy sources has restrictions; in the case of wave energy, high installation, maintenance, and decommissioning costs have limited their commercial use. Moreover, these offshore operations...

This paper presents a step towards the grid connection of a wave energy park through an electric power conversion system (EPCS) developed and installed for the wave energy harvesting in Lysekil, Sweden. The EPCS comprises of a rectifier, a DC-bus, and an inverter followed by a harmonic filter. The higher and lower order harmonics injected by the...

This work presents results of power hardware in the loop testing of wave energy conversion. The wave energy converter (WEC) developed at Uppsala University is a point absorber equipped with a direct driven linear generator power take off. The hydrodynamic model of the WEC was implemented in Simulink using state space method to obtain positions...

Ocean can provide an inexhaustible amount of energy. Many marine energy converters have been developed but most of them have not surpassed the experimental phase due to the high costs in installation, operation, and maintenance. Since 2002 Uppsala University has developed and deployed several units of wave energy converters of various designs. The...

Output power fluctuations from a wave energy converter (WEC) utilizing the principle of an oscillating body are unavoid- able due to the reciprocating movement of the translator inside the generator. Moreover, the wave energy flux largely varies with time and propagates with the wave group velocity. Making use of the oscillating output power is a...

Output power fluctuations from a wave energy converter (WEC) utilizing the principle of an oscillating body are unavoidable due to the reciprocating movement of the translator inside the generator. Moreover, the wave energy flux largely varies with time and propagates with the wave group velocity. Making use of the oscillating output power is a cha...

The concept of the wave energy converter, developed at Uppsala University is based on a linear generator. Direct power take off mechanism is applied in the system. Optimization of wave energy converter by maximizing its average output power is carried out. In this paper, the passive control by a resistive load is applied in the model. The generator...

This paper provides an overview of electric power conversion system installed at the Lysekil research site, located at the west coast of Sweden. The electric power conversion system consists of rectifiers, rectifying the power from the wave energy converters, a DC-link and a grid-tied inverter. The paper focuses on the performance of the inverter a...

A wave energy converter (WEC) should be controlled in order to increase the average output power. In this paper, economic aspects of latching applied to a point absorbing WEC with a linear generator power take-off (PTO) are discussed. The capacity utilisation factor (CUF) is suggested to be used along with average absorbed power for control optimis...

Ocean renewable technologies have been rapidly developing over the past years. However, current high installation, operation, maintenance, and decommissioning costs are hindering these offshore technologies to reach a commercialization stage. In this paper we focus on the use of divers and remotely-operated vehicles during the installation and moni...

The wave energy converter (WEC) studied and developed at Uppsala University in Sweden is a point absorbing buoy connected to a linear generator (LG) on the seabed. Previous studies have improved the sustainability of the generator, changing its magnets from Nd2Fe14B-magnets to ferrites. In this paper, the magnetic circuit of the linear generator is...

This simulation study shows that it is possible to use a mix of different types of ferrite permanent magnets and different designed pole shoes in the linear generator and still obtain a similar magnetic energy in the airgap between the stator and translator as for previous designs. Different types of ferrite permanent magnets, Y30 and Y40, and diff...

Control of a wave energy converter (WEC) can provide a substantially improved output power. Control strategies proposed so far are mainly focused on mechanical models for force control such as phase control and reactive power control and implemented using boundary element method (BEM) based codes such as WAMIT to find hydrodynamic forces. This appr...

With the prospect to deploy hydrokinetic energy converters in areas with heavy boat traffic, a study was conducted to observe and assess the depth range of cavitating flow produced by ferryboats in narrow channels. This study was conducted in the vicinity of Finnhamn Island in Stockholm Archipelago. The objectives of the survey were to assess wheth...

Since 2008, Seabased Industry AB (SIAB) has manufactured and deployed several units of wave energy converters (WECs) of different design. The WECs are linear generators with point absorber buoy systems that are placed on the seabed, mounted on a gravitation concrete foundation. These deployments have taken place in different areas, using different...

Many power electronic applications demand generation of voltage of a rather good sinusoidal waveform. In particular, dc-to-ac voltage conversion could be done by multilevel inverters (MLI). A number of various inverter topologies have been suggested so far: diode-clamped (DC) MLI, capacitor-clamped (CC) MLI, cascaded H-bridge (CHB) MLI, and others....

The term dead time refers to a prime safety factor for most power electronic converter topologies, and it is included either in the control software or in the gate/base driver hardware, depending on the application as well as the control requirements. In this paper, the authors present a comprehensive numerical analysis of dead-time effects on the...

The wave power project at the Division of Electricity, Uppsala University, started in 2001. The first full - scale wave energy converter (WEC) was developed and deployed outside the Swedish West coast in 2006. Since then, another 13 WECs have been deployed. In order to transfer the absorbed wave energy to the shoreline, offshore marine substations...

Within the year 2013, four linear generators with point absorber buoy systems were deployed in the Lysekil test site. Until now, deployments of these point absorbing wave energy converters have been expensive, time consuming, complicated and raised safety issues. In the present paper, we focus on the analysis and optimization of the offshore deploy...

It is proved that the second cohomology group of the conformal algebras Cendn and Curn with coefficients in any bimodule is trivial. As a result, these algebras are segregated in any extension with a nilpotent kernel.

We introduce the concept of Hochschild cohomologies for associative conformal algebras. It is shown that the second cohomology group of a conformal Weyl algebra with values in any bimodule is trivial. As a consequence, we derive that the conformal Weyl algebra is segregated in any extension with nilpotent kernel.