Design and control of harbour area smart grids with application of battery energy storage system

Global trade occurs mostly on seaborne vessels, and harbours exist as the most significant part for enabling the economic development of any country. However, the amount of fossil fuels used by conventional diesel-engine powered vessels produce a great number of types of toxic emissions, such as air pollution particles at harbours, which create a threat to human health that can contribute to higher morbidity and mortality rates among humans. Therefore, the International maritime organisation and the European Directives recommend that ships implement methods that limit toxic gas emissions and air pollution, such as using onshore power supply and fuel with low-sulphur content for on-board power generation in vessels while remaining at harbours. This research presents cutting-edge methods and tools for contributing to the development of future marine solutions and analyses of modern vessel technological requirements as well as harbour grids, and it proposes novel models of harbour area smart grids for facilitating the support of onshore power supply and charging of batteries for those vessels that require it. This research explores the usage of multiple battery-charging configurations with either slow- or fast-charging systems for electric or hybrid vessels, and it analyses the technical challenges that could inhibit or prevent the practicality of their implementation. The suitable size and allocation of battery energy storage systems for real-world case power systems of Åland Islands harbour grid are also investigated to enhance power capacity of harbour grids. Moreover, a control algorithm for the battery energy storage controller was first developed in MATLAB/Simulink for the Vaasa harbour grid, and then its performance was tested in the OPAL-RT real-time simulator by conducting a controller hardware-in-the-loop test to maintain the power balance inside the harbour grid. The proposed harbour grid models can reduce the degree of pollution that degrades the environment while providing onshore power supply and battery-charging stations for hybrid or electric vessels. Moreover, this dissertation acts as a foundation for developing future business strategies for ship owners, port administrators, and local authorities to solve similar problems as technology develops and environmental degradation continues to be a problem of every country in the world.Maailmanlaajuinen kauppa tapahtuu pääasiassa merialuksilla, ja satamista on tulossa merkittävin osa minkä tahansa maan talouskehitystä. Perinteisten dieselmoottorialusten käyttämä fossiilinen polttoaine aiheuttaa kuitenkin satamissa monenlaisia myrkyllisiä päästöjä ja ilmansaasteita, jotka ovat uhka ihmisten terveydelle ja aiheuttavat monenlaisia vaarallisia sairauksia. Tästä syystä Kansainvälinen merenkulkujärjestö IMO ja EU-direktiivit suosittelevat, että alukset käyttävät satamissa ollessaan maalta tulevaa sähkönsyöttöä tai vähärikkistä polttoainetta myrkyllisten kaasupäästöjen ja ilmansaasteiden rajoittamiseksi. Tämä tutkimus esittelee uusimpia ja tulevaisuuden merenkulun ratkaisuja, analysoi nykyaikaisten alusten teknisiä vaatimuksia sekä satamaverkkoja ja esittelee uusia malleja satama-alueen älykkäille sähköverkoille, joilla tuetaan maasähkön käyttöä ja akkujen lataamista vaativia aluksia. Tutkimuksessa tarkasteltiin useita akkuenergiavarastojen latauskonfiguraatioita sekä hitailla että nopeilla latausjärjestelmillä sähkö-/hybridialuksille ja analysoitiin niiden käytännön toteutukseen liittyviä teknisiä haasteita. Akkuenergiavarastojen sopivaa kokoa ja sijoittelua satamaverkkojen tehokapasiteetin parantamiseksi selvitettiin todelliseen verkkoon perustuvassa tapaustutkimuksessa, jossa parannettiin Ahvenanmaan verkon satamien tehokapasiteettia. Lisäksi kehitettiin akkuenergiavarastojen ohjausalgoritmi tehotasapainon ylläpitämiseksi Vaasan satamaverkossa ensin MATLAB/Simulink-mallina, jonka jälkeen sen suorituskykyä testattiin OPAL-RT reaaliaika-simulaattorilla suorittamalla ns. laitesilmukkasimulaatioita. Ehdotetuilla satamaverkkomalleilla voidaan vastata ilmansaasteista aiheutuviin ympäristöongelmiin sekä mahdollistaa maasähkönsyöttö ja akkujen latausasemat tuleville hybridi- ja sähköaluksille. Lisäksi tämä väitöskirja voi toimia pohjana uusien liiketoimintastrategioiden kehittämiselle alusten omistajien, satamajohtajien ja paikallisviranomaisten tarpeisiin.fi=vertaisarvioitu|en=peerReviewed

The computational efficiency of Monte Carlo breakage of articles using serial and parallel processing : a comparison

This paper presents a GPU-based parallelized and a CPU-based serial Monte-Carlo method for breakage of a particle. We compare the efficiency of the graphic card’s graphics processing unit (GPU) and the general-purpose central processing unit (CPU), in a simulation using Monte Carlo (MC) methods for processing the particle breakage. Three applications are used to compare the computational performance times, clock cycles and speedup factors, to find which platform is faster under which conditions. The architecture of the GPU is becoming increasingly programmable; it represents a potential speedup for many applications compared to the modern CPU. The objective of the paper is to compare the performance of the GPU and Intel Core i7-4790 multicore CPU. The implementation for the CPU was written in the C programming language, and the GPU implemented the kernel using Nvidia’s CUDA (Compute Unified Device Architecture). This paper compares the computational times, clock cycles and the speedup factor for a GPU and a CPU, with various simulation settings such as the number of simulation entries (SEs), for a better understanding of the GPU and CPU computational efficiency. It has been found that the number of SEs directly affects the speedup factor.fi=vertaisarvioitu|en=peerReviewed

Monitoring and analysis of low-voltage network with smart grid architecture model by developing use cases

The objective of this paper is to show the characteristics of smart meters enabling to monitor and analyze the low-voltage (LV) network. This is achieved by developing use cases, where power quality and outage data are transferred from smart meters through distribution network to the control center. To visualize the monitoring process of LV network, the use cases are mapped into smart grid architecture model. The paper proposes a solution to analyze the LV network interruption and power quality problems (over-voltage, under-voltage, voltage sags, and swells). Thus, this paper provides a smart platform for monitoring LV network.© 2021 Authors. This work is licensed under the Creative Commons Attribution-Non-Commercial-NoDerivs 4.0 License https://creativecommons.org/licenses/by-nc-nd/4.0/.fi=vertaisarvioitu|en=peerReviewed

Smart Control of Battery Energy Storage System in Harbour Area Smart Grid : A Case Study of Vaasa Harbour

Battery energy storage system plays an essential role for optimally controlling and managing power of modern harbour grids so as to support electric vessels requiring onshore power supply and battery charging system. Designing an appropriate size of battery energy storage system of any harbour grid require precise data of power consumption as well future planned load. This paper presents a practical approach where a charge/discharge strategy is applied in such a way that peak-load demand of harbour grid is shaved off by discharging the battery during peak demand load and charging it during off-peak load demand. A suitable battery energy storage system along with its control algorithm is designed for Vaasa harbour grid with the obtained real data of annual power consumption and available power resources. Vaasa harbour grid model is developed in MATLAB/Simulink and a control algorithm is developed for the power flow to and from battery energy storage system by charging and discharging through bi-directional dc-dc converter. The results show that battery energy storage system is a suitable solution for harbour grids to cope with growing demand of new electric ships optimally in harbour grid without extensive renovation of the power supply infrastructure.©2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.fi=vertaisarvioitu|en=peerReviewed

A Smart Under-Frequency Load Shedding Scheme based on Takagi-Sugeno Fuzzy Inference System and Flexible Load Priority

This paper proposes a new smart under frequency load shedding (UFLS) scheme, based on Takagi-Sugeno (TS) fuzzy inference system and flexible load priority. The proposed scheme consists of two parts. First part consists of fuzzy load shed amount estimation module (FLSAEM) which uses TS-fuzzy to estimate the amount of load shed and sends its value to accurate load shedding module (ALSM) to perform accurate load shedding using flexible load priority. The performance of the proposed scheme is tested for intentional islanding case and increment of sudden load in the system. Moreover, the response of the proposed scheme is compared with adaptive UFLS scheme to highlight its advantages. The simulation results show that the proposed UFLS scheme provides the accurate load shedding due to advantage of flexible priority whereas adaptive UFLS scheme due to fixed load priority does not succeed to achieve accurate load shedding.fi=vertaisarvioitu|en=peerReviewed

Analysis of Spatially Modelled High Temperature Polymer Electrolyte Membrane Fuel Cell under Dynamic Load Conditions

This paper presents an interesting approach to observe the effects of the load variations on the performance of high temperature polymer electrolyte membrane fuel cell system, such as: hydrogen and air flow rate, output voltage, power and efficiency. The main advantage of this approach is to analyse the internal behaviour of the fuel cell like current-voltage characteristics during energy conversion, when the load is varying dynamically. This approach of power system simulation models fuel cell system by integrating 3D-COMSOL model of high temperature polymer electrolyte membrane fuel cell with MATLAB/Simulink model of the fuel cell system. The MATLAB/Simulink model for the fuel cell system includes the fuel cell stack (single cell), load (sequence of currents), air supply system (air compressor), fuel supply system (hydrogen tank), and power-efficiency block. The MATLAB/Simulink model is developed in such a way that one part behaves as an input model to the 3D-COMSOL model of the fuel cell system, whereas second part behaves as an output model that recovers the results obtained from the 3D-COMSOL of the fuel cell. This approach of power system modelling is useful to show the performance of high temperature polymer electrolyte membrane fuel cell in much better and accurate way.fi=vertaisarvioitu|en=peerReviewed

Ponseti Technique in Neglected Club Foot Children with Age between 3 and 11 Years

OBJECTIVE: To evaluate the Ponseti treatment in neglected club foot patients. Result of this study shall help us to manage untreated or neglected patients with club foot in better way and this study shall provide platform for bigger studies on clubfoot in Pakistan. METHODOLOGY: This multicentre observational cross sectional study was conducted on retrospective data of patients registered to Ponseti Club foot Clinic between July 2013 to Dec 2016 at Dr Ruth Pfau Civil Hospital Karachi and Jinnah postgraduate Medical Center, Karachi. In this study 41 feet in 28 patients with Neglected club foot between 3 to 11 years were treated by Ponseti guidelines for older child (already walking child). Deformity was assessed with pirani scoring. Average follow up time was 3 years. RESULTS: Painless plantigrate foot was obtained in all patients. In 3 patients equinus deformity recurred. Two were managed with recasting while in the third one along with recasting and retenotomy was undertaken. In 2 patients mild varus was recurred, which was managed with recasting. One patient was lost to follow-up after 2 years. CONCLUSION: This study conclude that treatment of neglected idiopathic club foot patients presenting to us after walking age with Ponseti method according to Ponseti guidelines for older children is safe, effective and low cost method. It also reduces the risk of excessive surgical procedures

Design and Implementation of Model Predictive Control for Parallel Distributed Energy Resource in Islanded AC Microgrids

This study proposes the voltage control strategy for distributed energy resource (DER) in islanded AC microgrids (MG). Typically, AC MG can maintain a constant voltage at the point of common coupling (PCC) as well as perform power-sharing among the DERs. However, linear controllers have several restrictions such as slow transient response, poor disturbance rejection capability etc. Therefore, this study presents an FCS-MPC for a DER with effective voltage regulation capability. The investigated work demonstrates excellent steady-state performance, a low computational burden, better response under transients and have low switching frequency as compared to linear control. First, the benefits of FCS-MPVC for single DER has been studied, then the same topology along with droop control is employed for multiple DERs in AC MG to serve the load. Droop control shows improved power-sharing among the DERs. The performance of the proposed control technique is demonstrated through MATLAB/Simulink simulations for single DG and AC MG under linear, non-linear loading conditions.©2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.fi=vertaisarvioitu|en=peerReviewed

Real-time testing of a battery energy storage controller for harbour area smart grid : A case study for Vaasa harbour grid

Battery energy storage system makes seaport microgrids more reliable, flexible, and resilient. However, it is necessary to develop, test, and validate the functionality of battery energy storage controller in such a way that it balances power mismatch of demand and supply by charging and discharging the battery. This paper examines the performance of battery energy storage controller (BESC) to be employed in harbour grids in such a way that mismatch of power supply and load demand is compensated by charging and discharging the battery energy storage system. This controller can save energy efficiently and shave peak load demand in harbour grids where transmission and distribution systems have a limited power capacity. The controller of battery energy storage system is first developed offline in the MATLAB/Simulink, and then implemented with IEC61850 communication protocol for publishing and subscribing GOOSE messages. Moreover, to test the effectiveness of the proposed control algorithm of battery energy storage system, a real data from the local distribution system operator Vaasan Sähköverkko and harbour operator Kvarken port of Vaasa has been implemented. The simulation results show that the designed battery energy storage controller can balance power inside microgrid by charging and discharging of battery storage. The applied technique used in this paper is useful to validate the controller functionality in real time with the concept of simulation-in-loop (SIL), which is a practical approach, and it provides a cost-effective way to observe the performance of the controller.© 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.fi=vertaisarvioitu|en=peerReviewed