Mare Baikal cum partibus fluviorum Lenae, Argun Selengae et Angarae ac circumjacentibus territoriis

Kartta kuuluu A. E. Nordenskiöldin kokoelmaan

Orbis terrae compendiosa descriptio : quam ex Magna Universali Gerardi Mercatoris domino Richardo Gartho, geographiae ac caeterarum bonarum artium amatori ac fautori summo, in veteris amicitiae ac familiaritatis memoriam

Kartta kuuluu A. E. Nordenskiöldin kokoelmaan

Europa religionis christianiae morum et pacis ac belli artium cultu omnium terrarum orbis partium praestantiss.

Kartta kuuluu A. E. Nordenskiöldin kokoelmaan

Study of Control Methods of a High-Frequency Cycloconverter for Domestic Induction Heating Appliances

A high-frequency cyclonverter acts as a direct ac-to-ac power converter circuit that does not require a diode bidge rectifier. Bridgeless topology makes it possible to remove forward voltage drop losses that are present in a diode bridge. In addition, the on-state losses can be reduced to 1.5 times the on-state resistance of switches in half-bridge operation of the cycloconverter. A high-frequency cycloconverter is reviewed and the charging effect of the dc-capacitors in ``back-to-back'' or synchronous mode operation operation is analyzed. In addition, a control method is introduced for regulating dc-voltage of the ac-side capacitors in synchronous operation mode. The controller regulates the dc-capacitors and prevents switches from reaching overvoltage level. This can be accomplished by variating phase-shift between the upper and the lower gate signals. By adding phase-shift between the gate signal pairs, the charge stored in the energy storage capacitors can be discharged through the resonant load and substantially, the output resonant current amplitude can be improved. The above goals are analyzed and illustrated with simulation. Theory is supported with practical measurements where the proposed control method is implemented in an FPGA device and tested with a high-frequency cycloconverter using super-junction power MOSFETs as switching devices.

Modular Double-Cascade Converter

Medium-voltage motor drives extend the power rating of AC motor drives in industrial applications. Multilevel converters are gaining an ever-stronger foothold in this field. This doctoral dissertation introduces a new topology to the family of modular multilevel converters: the modular double-cascade converter. The modularity of the converter is enabled by the application of multiwinding mediumfrequency isolation transformers. Owing to the innovative transformer link, the converter presents many advantageous properties at a concept level: modularity, high input and output power quality, small footprint, and wide variety of applications, among others. Further, the research demonstrates that the transformer link also plays a key role in the disadvantages of the topology. An extensive simulation study on the new converter is performed. The focus of the simulation study is on the development of control algorithms and the feasibility of the topology. In particular, the circuit and control concepts used in the grid interface, the coupling configurations of the load inverter, and the transformer link operation are thoroughly investigated. Experimental results provide proof-of-concept results on the operation principle of the converter. This work concludes a research collaboration project on multilevel converters between LUT and Vacon Plc. The project was active from 2009 until 2014.

Nova et accuratissima tabula regionum ad Sinum Finnicum. Exactissimo delineata ac sumneo studio recognito ab Henrico de Leth.

[N. 1:1200000].

Europa religionis christianae, morum, et pacis ac belli artium cultu omnium terrar: orbis partiu[m] praesantiß: juxta recent[issi]ma exempl: accurat[issi]ma excusa a Matth. Seuttero s. c. m. geogr.

[N. 1:27000000].

Nova mappa geographica Sueciae ac Gothiae regna ut et Finlandiae ducatum ac Lapponiam, cum provinciis minoribus, ob oculos ponens, cura et sumtibus Tobiae Conradi Lotter, chalcogr et geogr: Augustae Vindel.

Alareunassa privilegiomerkintä: Cum gratia et privil. s. r. i. vicariatq, in partibq Rheni, Sveviae, et juris Franconici.

Fons lacrymarum Sveo-Gothicae gentis, per theoriam solis ad d. April. 5 anni M.DC.XCVII

Jehovah auxiliante!

De Spiritu Sancto, et aeterna eius divinitate ac processione; nec non officio atque donis

Invokaatio: Sun to Theo trisbeltiso kai megiso.

Fasciculus physicae ejusdem illustriores definitiones, divisiones, atque nobiliores controversias axiomatibus nonnullis insertas brevibusque rationibus firmatas ac enodatas continens

Arkit: 4 arkintunnuksetonta lehteä, A-F8 G4.

Zetémata quaedam ex spatioso ac fructuoso philosophiae agro excerpta

Invokaatio: Cum Deo.

De theologiae natura, ad decretum venerandae facultatis theologicae, moderatore plurimum reverendo, amplissimo ac praeclarissimo dn. Abrahamo Thauvonio, s. s. theol. doctore & professore ord: p. t. magnifico rectore, boni ominis [!] causa, ante introductionem suam disputabit Petrus Bång Hels. In auditorio majore die 9. Decemb. anno 1665

Invokaatio: I.N.J.

Themata nonnulla theoretica simul ac practica duabus sectionibus inclusa

Invokaatio: Auxilio Jehovae.

Summa rerum genera esse tantum duo: substantiam nimirum & accidens, ex suffragio ampliss. facult. philos. in florentissimo ad Auram Athenaeo, sub umbone ... dn. mag. Simonis Tålpo, met & log. professoris famigeratissimi, consistorii Acad. assessoris gravissimi nec non annexae Pijkensis pastoris longe fidelissimi. Summos in philosophia honores aditurus dissertatione philosophica ad sobrie philosophantium examen modeste delata statuere conabitur Jeremias Wallenius J. f. Tavastensis. Ad diem 21. Nov. anni redempti orbis M. DC. XC. IV. Horis pomeridianis in auditorio maximo

Invokaatio: A.J.