Helsingin seudun liikenteenhallinnan kärkihankkeiden päivitys 2011

Työn tavoitteena oli kokonaisnäkemyksen luominen Helsingin seudun liikenteenhallinnan tilasta ja kehitysnäkymistä sekä seuraavien tärkeimpien kehittämispolkujen tunnistaminen ja konkretisointi toimenpiteiksi. Työssä keskityttiin seuraaviin painopistealueisiin 1. Liityntäpysäköinnin informaation ja maksujärjestelmien kehittäminen 2. Liikenteenhallintakeskuksen toiminnan kehittäminen ja laajentaminen 3. Liikennejärjestelmän reaaliaikainen tilannekuva ja lyhyen aikavälin ennusteet 4. Pääkaupunkiseudun pääväylien ruuhkien ja häiriöiden hallinta 5. Joukkoliikenteen ajantasaisen matkustajainformaation kehittäminen. Työssä laadittiin katsaus kullakin painopistealueella jo tapahtuneeseen sekä käynnissä olevaan kehitystyöhön, kuvattiin esiin nousseita ongelmia ja laadittiin esitys vuoteen 2020 ulottuvasta toiminnallisesta tavoitetilasta sekä konkreettisista kehittämistoimista. Työssä järjestettiin myös tulevaisuustyöpaja, johon pyydettiin alustuksia valikoiduilta viranomaistahoilta, tutkijoilta ja palveluntuottajilta. Näiden keskustelujen kautta kirkastettiin seudun toimijoiden näkemystä älyliikenteen toimialan kehitysnäkymistä ja –tarpeista. Työn lopputuloksena syntyneeseen toimenpideohjelmaan kirjattiin yhteensä 30 hanketta. Näistä viisi hanketta valittiin työpajatyöskentelyn kautta varsinaisiksi kärkihankkeiksi, joiden toteutus on kriittistä liikkujien ja viranomaistyön palvelutason kannalta ja joka edellyttää usean toimijan yhteistyötä. Lisäksi tunnistettiin joukko seurattavia hankkeita. Valitut kärkihankkeet, käynnistämisen vastuutaho sekä tavoitteellinen käynnistysvuosi ovat seuraavat: 1. Liityntäpysäköinnin dynaamisen informaatiojärjestelmän pilotointi Hämeenlinnanväylän käytävässä Kehäradan asemilla (HSL 2012) 2. HSL:n alueen joukkoliikenteen häiriönhallinnan uudelleenorganisointi (HSL, Liikennevirasto 2012) 3. Seudullisen liikenteenhallintasuunnitelman laadinta verkollisen operoinnin kehittämiseksi häiriötilanteissa (ELY-keskus, Liikennevirasto 2013) 4. Reaaliaikaisen sujuvuustiedon tuottaminen ruuhkautuvalta pääkatu- ja alempiasteiselta maantieverkolta (Liikennevirasto, kunnat 2012) 5. Liikenteen vaihtuvan ohjauksen ja tiedottamisen hyödyntäminen pääväylien ruuhkautumisen ja häiriöiden hallinnassa. (ELY-keskus 2012) Kärkihankkeisiin ei liity sellaisia riippuvuuksia, että niitä ei voitaisi käynnistää ennen päätöksentekoa jostakin muusta investoinnista. Merkittävimmät riippuvuudet liittyvät LIJ2014-järjestelmän ajoneuvojen paikannuksen ja muiden työkalujen valmistumiseen. Johtoryhmän linjauksen mukaan kärkihankkeissa ja muissakin toimijoiden omissa hankkeissa syntyvien tietojärjestelmien rajapinnat avataan soveltuvasti kaupallisten toimijoiden käyttöön, jolloin syntyvien kaupallisten loppukäyttäjäpalveluiden kautta voidaan parantaa tietopalvelujen tavoittavuutta. Kärkihankkeiden valinta ja sisältö on rakennettu pitkälti sen lähtökohdan varaan, että liikenteen tietopalveluissa julkistoimijoiden roolina on pääasiassa lähtötietojen tuottaminen ja jakaminen varsinaisille palveluntuottajille. Vuoteen 2016 mennessä uusien rajapintojen kautta jaettavien tietojen määrä on nykyiseen verrattuna huomattavasti laajempi, ja odotukset uusien ja innovatiivisten palvelujen syntymiselle ovat korkeat. HLH-johtoryhmä nimeää jokaisen kärkihankkeen läpiviennistä vastaavan työryhmän, joiden työskentelyä ohjataan nykyisen kaltaisessa johtoryhmätyössä. Johtoryhmätyön organisointi on todettu toimivaksi, sillä ryhmä koostuu seudun 14 kunnan alueen keskeisistä julkisista toimijoista ja sen kautta on olemassa vahvat kytkennät sekä seudun liikennejärjestelmätyöhön (HLJ) että valtakunnalliseen älyliikenteen kehitystyöhön.

Variable speed drive in fan system monitoring

Fan systems are responsible for approximately 10% of the electricity consumption in industrial and municipal sectors, and it has been found that there is energy-saving potential in these systems. To this end, variable speed drives (VSDs) are used to enhance the efficiency of fan systems. Usually, fan system operation is optimized based on measurements of the system, but there are seldom readily installed meters in the system that can be used for the purpose. Thus, sensorless methods are needed for the optimization of fan system operation. In this thesis, methods for the fan operating point estimation with a variable speed drive are studied and discussed. These methods can be used for the energy efficient control of the fan system without additional measurements. The operation of these methods is validated by laboratory measurements and data from an industrial fan system. In addition to their energy consumption, condition monitoring of fan systems is a key issue as fans are an integral part of various production processes. Fan system condition monitoring is usually carried out with vibration measurements, which again increase the system complexity. However, variable speed drives can already be used for pumping system condition monitoring. Therefore, it would add to the usability of a variablespeed- driven fan system if the variable speed drive could be used as a condition monitoring device. In this thesis, sensorless detection methods for three lifetime-reducing phenomena are suggested: these are detection of the fan contamination build-up, the correct rotational direction, and the fan surge. The methods use the variable speed drive monitoring and control options for the detection along with simple signal processing methods, such as power spectrum density estimates. The methods have been validated by laboratory measurements. The key finding of this doctoral thesis is that a variable speed drive can be used on its own as a monitoring and control device for the fan system energy efficiency, and it can also be used in the detection of certain lifetime-reducing phenomena.

Energy-efficient control strategies for variable speed driven parallel pumping systems based on pump operation point monitoring with frequency converters

The pumping processes requiring wide range of flow are often equipped with parallelconnected centrifugal pumps. In parallel pumping systems, the use of variable speed control allows that the required output for the process can be delivered with a varying number of operated pump units and selected rotational speed references. However, the optimization of the parallel-connected rotational speed controlled pump units often requires adaptive modelling of both parallel pump characteristics and the surrounding system in varying operation conditions. The available information required for the system modelling in typical parallel pumping applications such as waste water treatment and various cooling and water delivery pumping tasks can be limited, and the lack of real-time operation point monitoring often sets limits for accurate energy efficiency optimization. Hence, alternatives for easily implementable control strategies which can be adopted with minimum system data are necessary. This doctoral thesis concentrates on the methods that allow the energy efficient use of variable speed controlled parallel pumps in system scenarios in which the parallel pump units consist of a centrifugal pump, an electric motor, and a frequency converter. Firstly, the suitable operation conditions for variable speed controlled parallel pumps are studied. Secondly, methods for determining the output of each parallel pump unit using characteristic curve-based operation point estimation with frequency converter are discussed. Thirdly, the implementation of the control strategy based on real-time pump operation point estimation and sub-optimization of each parallel pump unit is studied. The findings of the thesis support the idea that the energy efficiency of the pumping can be increased without the installation of new, more efficient components in the systems by simply adopting suitable control strategies. An easily implementable and adaptive control strategy for variable speed controlled parallel pumping systems can be created by utilizing the pump operation point estimation available in modern frequency converters. Hence, additional real-time flow metering, start-up measurements, and detailed system model are unnecessary, and the pumping task can be fulfilled by determining a speed reference for each parallel-pump unit which suggests the energy efficient operation of the pumping system.

Lebesgue and Sobolev spaces with variable exponents

Kirjallisuusarvostelu

Doubly fed wind turbine performance in variable grid conditions

Wind turbines based on doubly fed induction generators (DFIG) become the most popular solution in high power wind generation industry. While this topology provides great performance with the reduced power rating of power converter, it has more complicated structure in comparison with full-rated topologies, and therefore leads to complexity of control algorithms and electromechanical processes in the system. The purpose of presented study is to present a proper vector control scheme for the DFIG and overall control for the WT to investigate its behavior at different wind speeds and in different grid voltage conditions: voltage sags, magnitude and frequency variations. The key principles of variable-speed wind turbine were implemented in simulation model and demonstrated during the study. Then, based on developed control scheme and mathematical model, the set of simulation is made to analyze reactive power capabilities of the DFIG wind turbine. Further, the rating of rotor-side converter is modified to not only generate active rated active power, but also to fulfill Grid Codes. Results of modelling and analyzing of the DFIG WT behavior under different speeds and different voltage conditions are presented in the work.

Variable-speed-drive-based detection methods for problems in fluid handling systems

Fluid handling systems account for a significant share of the global consumption of electrical energy. They also suffer from problems, which reduce their energy efficiency and increase life-cycle costs. Detecting or predicting these problems in time can make fluid handling systems more environmentally and economically sustainable to operate. In this Master’s Thesis, significant problems in fluid systems were studied and possibilities to develop variable-speed-drive-based detection methods for them was discussed. A literature review was conducted to find significant problems occurring in fluid handling systems containing pumps, fans and compressors. To find case examples for evaluating the feasibility of variable-speed-drive-based methods, queries were sent to industrial companies. As a result of this, the possibility to detect heat exchanger fouling with a variable-speed drive was analysed with data from three industrial cases. It was found that a mass flow rate estimate, which can be generated with a variable speed drive, can be used together with temperature measurements to monitor a heat exchanger’s thermal performance. Secondly, it was found that the fouling-related increase in the pressure drop of a heat exchanger can be monitored with a variable speed drive. Lastly, for systems where the flow device is speed controlled with by a pressure measurement, it was concluded that increasing rotational speed can be interpreted as progressing fouling in the heat exchanger.

Performance Degradation Modelling and Techno-Economic Analysis of Lithium-Ion Battery Energy Storage Systems

Transmission system operators and distribution system operators are experiencing new challenges in terms of reliability, power quality, and cost efficiency. Although the potential of energy storages to face those challenges is recognized, the economic implications are still obscure, which introduce the risk into the business models. This thesis aims to investigate the technical and economic value indicators of lithium-ion battery energy storage systems (BESS) in grid-scale applications. In order to do that, a comprehensive performance lithium-ion BESS model with degradation effects estimation is developed. The model development process implies literature review on lifetime modelling, use, and modification of previous study progress, building the additional system parts and integrating it into a complete tool. The constructed model is capable of describing the dynamic behavior of the BESS voltage, state of charge, temperature and capacity loss. Five control strategies for BESS unit providing primary frequency regulation are implemented, in addition to the model. The questions related to BESS dimensioning and the end of life (EoL) criterion are addressed. Simulations are performed with one-month real frequency data acquired from Fingrid. The lifetime and cost-benefit analysis of the simulation results allow to compare and determine the preferable control strategy. Finally, the study performs the sensitivity analysis of economic profitability with variable size, EoL and system price. The research reports that BESS can be profitable in certain cases and presents the recommendations.