Luistonestojärjestelmän ja elektronisen tasauspyörästön testaus ja implementointi hybridityökoneympäristöön

Työssä toteutettiin C-kielellä luistonestojärjestelmä ja elektroninen tasauspyörästö Simulinkmallien pohjalta hybridityökoneeseen. Hybridityökoneen sähkökäytöt mahdollistavat tarkan vääntömomentin säädön, joka mahdollistaa työssä kuvatun kaltaisen järjestelmän toteuttamisen. Toteutettua järjestelmää simuloitiin MeVEA Oy:n ajoneuvomallinnukseen kehitetyssä simulaattorissa. Lisäksi järjestelmästä kehitettiin Visedo Oy:n sähkökäyttösimulaattoriin sopiva versio, jota testattiin Visedon sähkökäyttöjä simuloivan ohjelman kanssa. Simulointituloksien mukaan luistonesto estää vetäviä pyöriä luistamasta liukkaalla alustalla eikä toisaalta vähennä aiheetta kuljettajan asettamaa vääntömomenttia. Myös sähköinen tasauspyörästö toimi kuten oli suunniteltu. Työssä kehitetty luistonesto tarvitsee toimiakseen tiedon ajoneuvon kokonaismassasta, joten työssä kehitettiin myös tapa ajoneuvon massan estimoimiseksi ajoneuvon kiihdyttäessä. Massan estimointia testattiin pitävällä ja liukkaalla alustalla. Massan estimointi toimi simulaattoriympäristössä hyvällä tarkkuudella.

Marketing Plan of Electric Vehicle Charging Solutions to USA

The purpose of the Thesis was to evaluate the business environment of electrical vehicle charging equipment (EVSE) in USA, find the key issues of entering the US EVSE markets and to form a marketing plan for possible market entry. The external market research analyzed the environment, customers, competitors and demand of EVSEs. In the internal analysis the focus was on resources and capabilities, offering, performance, business relations and US related issues. The research about the business environment was done using already available information from market studies and seminars. In external analysis there were also two semi-structured interviews from market experts used. The internal analysis was done mostly by interviews, but also company’s internal data sources were used. The interviews were semi-constructed and included eight interviewees from each part of EVSE value chain. The research findings were analyzed using SWOT analysis, which was converted to a so called TOWS matrix for extracting strategies. As a result of the Thesis, valuable information about the US markets and their requirements for EVSEs was gained. By matching the strengths of the case company and market requirements, customer segmentation and targeting were done and a marketing plan was constructed for the case company to help their management to evaluate the feasibility of possible market entry and investments to USA.

Auger-type granular fertylizer distributor: matemathical model and dynamic simulation

The objective of this study was to model mathematically and to simulate the dynamic behavior of an auger-type fertilizer applicator (AFA) in order to use the variable-rate application (VRA) and reduce the coefficient of variation (CV) of the application, proposing an angular speed controller θ' for the motor drive shaft. The input model was θ' and the response was the fertilizer mass flow, due to the construction, density of fertilizer, fill factor and the end position of the auger. The model was used to simulate a control system in open loop, with an electric drive for AFA using an armature voltage (V A) controller. By introducing a sinusoidal excitation signal in V A with amplitude and delay phase optimized and varying θ' during an operation cycle, it is obtained a reduction of 29.8% in the CV (constant V A) to 11.4%. The development of the mathematical model was a first step towards the introduction of electric drive systems and closed loop control for the implementation of AFA with low CV in VRA.

Investment recovery period in electric motor of higher efficiency in pumping for irrigation

In this study, it was adjusted a mathematical model to measure the effect of electric motor efficiency on pumping system costs for irrigation on the tariff structure of conventional electricity and green horo-seasonal , and also to calculate the recovery period of the invested capital in higher efficiency equipment. Then, it was applied to a center pivot irrigation system in two options of electric motor efficiency, 92,6% (standard line) and 94,3% (high efficiency line), and the acquisition cost of the first corresponded to 70% the of the second. The power of the electric motor was 100hp. The results showed that the model allowed us to evaluate if a high efficiency motor was economically viable compared to the standard motor in each tariff structure. The high efficiency motor was not viable in the two tariff structures. In the green horo-seasonal tariff, would only be viable if its efficiency was 4.46% higher than the standard motor. In the conventional tariff, it would only be viable if the efficiency overcame 2.71%.

Monimoottorikäyttöjen suojaukset, mitoitus ja ohjeistus

Työssä tutkitaan pienitehoisen monimoottoritaajuusmuuttajakäytön yhteismuotovirtojen aiheuttamia ongelmia. Työn tavoitteena on muodostaa monimoottorikäyttöjen toteuttajille opastus, jonka avulla sähkökäytön suunnittelun alkuvaiheessa voidaan ottaa huomioon monimoottorikäytön erikoistarpeita. Työn teoriaosuudessa esitellään taajuusmuuttajan vaihtosuuntaustekniikan aiheuttamia ongelmia, moottorikaapelin mallintamista ja vertaillaan ongelmien ratkaisukeinoja pienitehoisten taajuusmuuttajien näkökulmasta. Yhteismuotoista virtaa tutkitaan mittaamalla rakennetulla monimoottorikäytöllä sekä simuloimalla vaihdellen kaapelin pituutta ja moottorien lukumäärää. Mittaamalla vertaillaan myös virran suodatusratkaisuja. Muodostettu simulointimalli on hyvin yksinkertainen ja luotettavammat virta-arvot saadaankin mittauksella. Kuitenkin työn perusteella voidaan antaa ohjeita monimoottorikäytön suunnittelulle. Esimerkiksi jokaiselle moottorille täytyy suunnitella erillinen suojaus ja taajuusmuuttaja on syytä mitoittaa todellisen kuormavirran mukaan. Yhteismuotoisen virran aiheuttamat ongelmat ovat sitä pienempiä, mitä vähemmän moottoreita on rinnakkain ja mitä lyhyempi moottorikaapelien yhteispituus on.

Aging based maintenance and reinvestment scheduling of electric distribution

The maintenance of electric distribution network is a topical question for distribution system operators because of increasing significance of failure costs. In this dissertation the maintenance practices of the distribution system operators are analyzed and a theory for scheduling maintenance activities and reinvestment of distribution components is created. The scheduling is based on the deterioration of components and the increasing failure rates due to aging. The dynamic programming algorithm is used as a solving method to maintenance problem which is caused by the increasing failure rates of the network. The other impacts of network maintenance like environmental and regulation reasons are not included to the scope of this thesis. Further the tree trimming of the corridors and the major disturbance of the network are not included to the problem optimized in this thesis. For optimizing, four dynamic programming models are presented and the models are tested. Programming is made in VBA-language to the computer. For testing two different kinds of test networks are used. Because electric distribution system operators want to operate with bigger component groups, optimal timing for component groups is also analyzed. A maintenance software package is created to apply the presented theories in practice. An overview of the program is presented.

Sähköajoneuvon sähkökäytön ja mekaniikan reaaliaikaisen yhdistelmäsimulaation toteuttaminen virtuaaliympäristössä

Esitetyn tutkimuksen tavoite on selvittää yksinkertaisen sähköajoneuvosimulaation avulla sähkökäyttösimulaation ja mekaniikkasimulaation välisen ohjelmallisen rajapinnan toimivuutta ja samalla toteuttaa LUT Energian hybridilaboratorion ensimmäinen rajapintaa hyödyntävä sähkökäytön ja mekaniikan yhdistelmäsimulaatio. Tutkimus on osa Lappeenrannan teknillisen yliopiston hybridikäyttötutkimusta, jossa muun muassa virtuaalisimuloinnin ja in-loop –simulaatioiden avulla tutkitaan raskaiden työkoneiden hybridisoinnin vaikutuksia esimerkiksi niiden suorituskykyyn, energiatehokkuuteen ja käytettävyyteen. Tulokset osoittavat mainitun rajapinnan toimivuuden, mikä mahdollistaa tutkimuksen etenemisen. Lisäksi raportti selvittää virtuaalisimuloinnin keskeisiä käsitteitä (virtual prototyping, hardware-in-the-loop sekä human-in-the-loop –simulointi).

Power cycling lifetime estimation of IGBT power modules based on chip temperature modeling

In this doctoral thesis, methods to estimate the expected power cycling life of power semiconductor modules based on chip temperature modeling are developed. Frequency converters operate under dynamic loads in most electric drives. The varying loads cause thermal expansion and contraction, which stresses the internal boundaries between the material layers in the power module. Eventually, the stress wears out the semiconductor modules. The wear-out cannot be detected by traditional temperature or current measurements inside the frequency converter. Therefore, it is important to develop a method to predict the end of the converter lifetime. The thesis concentrates on power-cycling-related failures of insulated gate bipolar transistors. Two types of power modules are discussed: a direct bonded copper (DBC) sandwich structure with and without a baseplate. Most common failure mechanisms are reviewed, and methods to improve the power cycling lifetime of the power modules are presented. Power cycling curves are determined for a module with a lead-free solder by accelerated power cycling tests. A lifetime model is selected and the parameters are updated based on the power cycling test results. According to the measurements, the factor of improvement in the power cycling lifetime of modern IGBT power modules is greater than 10 during the last decade. Also, it is noticed that a 10 C increase in the chip temperature cycle amplitude decreases the lifetime by 40%. A thermal model for the chip temperature estimation is developed. The model is based on power loss estimation of the chip from the output current of the frequency converter. The model is verified with a purpose-built test equipment, which allows simultaneous measurement and simulation of the chip temperature with an arbitrary load waveform. The measurement system is shown to be convenient for studying the thermal behavior of the chip. It is found that the thermal model has a 5 C accuracy in the temperature estimation. The temperature cycles that the power semiconductor chip has experienced are counted by the rainflow algorithm. The counted cycles are compared with the experimentally verified power cycling curves to estimate the life consumption based on the mission profile of the drive. The methods are validated by the lifetime estimation of a power module in a direct-driven wind turbine. The estimated lifetime of the IGBT power module in a direct-driven wind turbine is 15 000 years, if the turbine is located in south-eastern Finland.

Improving the inventory management and valuation process, Case: The Switch Drive Systems

The goal of this study is to create a new inventory valuation process for The Switch Drive Systems and to improve its inventory management practices. In the matter of inventories the main problems in the case company are that it doesn’t have consistent valuation methods throughout the company and that information received in ERP system isn’t trustful. The research is qualitative case study. The empirical data is gathered through observing and unstructured interviews. The research shows that material flow process and the inventory valuation must be divided and handled separately but they should interact with each other. The result is a new inventory valuation process which takes many factors of material process under the consideration in order to receive reliable value for inventories.

Design of an amplifier and an instrumentation setup for a harsh environment heat flux measurement application – case axial flux electric machine

Measurement is a tool for researching. Therefore, it is important that the measuring process is carried out correctly, without distorting the signal or the measured event. Researches of thermoelectric phenomena have been focused more on transverse thermoelectric phenomena during recent decades. Transverse Seebeck effect enables to produce thinner and faster heat flux sensor than before. Studies about transverse Seebeck effect have so far focused on materials, so in this Master’s Thesis instrumentation of transverse Seebeck effect based heat flux sensor is studied, This Master’s Thesis examines an equivalent circuit of transverse Seebeck effect heat flux sensors, their connectivity to electronics and choosing and design a right type amplifier. The research is carried out with a case study which is Gradient Heat Flux Sensors and an electrical motor. In this work, a general equivalent circuit was presented for the transverse Seebeck effect-based heat flux sensor. An amplifier was designed for the sensor of the case study, and the solution was produced for the measurement of the local heat flux of the electric motor to improve the electromagnetic compatibility.

Energy Efficiency Consideration in Electric Vehicle Transmission

This study is a survey of benefits and drawbacks of embedding a variable gearbox instead of a single reduction gear in electric vehicle powertrain from efficiency point of view. Losses due to a pair of spur gears meshing with involute teeth are modeled on the base of Coulomb’s law and fluid mechanics. The model for a variable gearbox is fulfilled and further employed in a complete vehicle simulation. Simulation model run for a single reduction gear then the results are taken as benchmark for other types of commonly used transmissions. Comparing power consumption, which is obtained from simulation model, shows that the extra load imposed by variable transmission components will shade the benefits of efficient operation of electric motor. The other accomplishment of this study is a combination of modified formulas that led to a new methodology for power loss prediction in gear meshing which is compatible with modern design and manufacturing technology.

Maastotyökoneen ajomoottorin hybridisointiin soveltuvan napavaihteiston dynamiikan mallinnus.

Työn tavoitteena oli mallintaa maastotyökoneen ajomoottorin hybridisointiin soveltuvan napavaihteiston dynamiikka. Työ tehtiin osana Saimaan ammattikorkeakoulun tutkimusprojektia, jonka tarkoituksena oli ajomoottorin ja integroidun napavaihteiston kaupallistaminen maastotyökoneisiin. Maastotyökoneena simulointimallissa käytettiin tyypillistä maataloustraktoria, johon kytkettiin vielä peräkärry. Traktorin renkaiden napaan oli kytketty ajomoottorina toimiva sähkömoottori, jonka sisään simuloitu napavaihteisto oli integroitu. Napavaihteiston dynamiikan mallintamiseen käytettiin monikappaledynamiikan simulointiohjelmistoa (Adams). Ohjelmalle määritettiin napavaihteiston komponenttien parametrit, joista voitiin simuloida vaihteiston dynaaminen käyttäytyminen. Simuloidusta mallista saatiin kytkimiin kohdistuvat voimat kytkentätilanteessa sekä sähkömoottorin väännön suunnanvaihtotilanteessa eri akselin pituuksilla, eri kytkinten nopeuseroilla, eri traktorin painoilla ja eri kuormilla ajettaessa. Mallissa simuloitiin myös sähkömoottorin käyttäytyminen vaihteenvaihtotilanteessa eri pyörimisnopeuden säätimen kertoimilla. Työssä huomattiin, että akselin mitoituksella voitiin vaikuttaa vaihteistossa ilmeneviin voimiin kytkimen kytkentähetkellä. Myös kytkimen hammastuksessa olevalla hammasvälyksellä voitiin vaikuttaa kytkimiin kohdistuviin voimiin suunnanvaihtotilanteissa. Vaihteistoon kohdistuvista voimista voidaan jatkossa suunnitella kytkimen ja akselin profiili, jotta vaihteisto kestää siihen kohdistuvat voimat.

Electric field control of magnetism in hydrid ferromagnetic / ferroelectric materials

Väisälän palkinnon 2012 saaja.

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.

Economical potential of controlling charging of electric vehicles by using price signal

The number of electric vehicles grows continuously and the implementation of charging electric vehicles is an important issue for the future. Increasing amount of electric vehicles can cause problems to distribution grid by increasing peak load. Currently charging of electric vehicles is uncontrolled, but as the amount of electric vehicles grows, smart charg-ing (controlled charging) will be one possible solution to handle this situation. In this thesis smart charging of electric vehicles is examined from electricity retailers` point of view. The purpose is to find out plausible saving potentials of smart charging, when it´s controlled by price signal. Saving potential is calculated by comparing costs of price signal controlled charging and uncontrolled charging.