A concept of an integrated and distributed inverter for switched reluctance machines is introduced. The application at hand outer-rotor direct drive designed railway traction applications. five-phase machine was developed used to demonstrate the function inverter. distribution achieved by supplying each phase coil with its own modular Each module placed evenly around end stator stack next dedicated coil. This increases redundancy significantly. likelihood phase-to-phase faults reduced,...

High power ultrashort pulsed lasers are an ultimate manufacturing tool for a large variety of materials and provide outstanding properties high precision with almost no thermal effects numerous new processing possibilities.However, using pulse repetition frequencies in the MHz region can cause issues like overheating, melt generation low ablation quality.High quality only be achieved, if all process parameters carefully matched, which requires deep understanding process, intensive simulation...

The dynamical behaviour of the laser beam fusion cutting process metals is investigated. Integral methods such as variational formulation are applied to partial differential equations for free boundary problem and a finite dimensional approximation system obtained. model describes shape evolving kerf melt flow. analysis aimed at revealing characteristic features resultant cut, example, ripple formation adherent dross. ripples in upper part where no resolidified material detectable, discussed...

This paper shows how electromagnetic air-gap forces in permanent magnet synchronous machines (PMSM) fed with non-sinusoidal currents can be efficiently simulated under arbitrary operating conditions based on a time-domain force interpolation approach. To account for spatial harmonics the stator currents, generic non-linear PMSM model including is introduced. Additional switching frequency components from inverter are generated common modulators. The harmonic machine itself applicable beyond...

Abstract Materials processing using ultrashort pulsed laser radiation with pulse durations <10 ps is known to enable very precise negligible thermal load. However, even for the application of picosecond and femtosecond radiation, not full amount absorbed energy converted into ablation products a distinct fraction remains as residual heat in processed workpiece. For low average power densities, this usually relevant results dissipates In contrast, when higher powers repetition rates are...

Laser metal deposition (LMD) process has been widely used in many industrial applications such as automotive, defense, aerospace, and so on. Modeling to address physical phenomena like laser-powder interaction, heat transfer, fusion, solidification, track formation. LMD induces a complex thermal stress field that results residual distributions. Depending on its magnitude nature (i.e., whether tensile or compressive), the stresses can cause unpredicted in-service failures. Therefore,...

A concept of an integrated and distributed inverter for switched reluctance machines is introduced. The application at hand outer-rotor direct drive designed railway traction applications. five-phase machine (SRM) was developed used to demonstrate the function inverter. distribution achieved by supplying each phase coil with its own modular Each module placed evenly around end stator stack next dedicated coil. This increases redundancy significantly. likelihood phase-to-phase faults reduced,...

Process inherent instabilities in the dynamics of thin melt film during laser fusion cutting reduce quality cut surface with regards to mean profile height and angular tolerance. To enhance process understanding identify evaluate improvement measures, a 3D model is developed applied experimental results from literature. cope multi-scale character mathematical task, reduction techniques are applied: underlying transport equations mapped conformal coordinate system subjected scaling analysis....

Drillings in zirconia coated Ni-superalloys is done by melt extraction with pulsed laser radiation provided a Nd:YAG slab microsecond pulse duration. This system distinguishes itself high beam quality and offers the possibility to investigate drilling of holes diameter 200 micrometer percussion trepanning. The drilled holes, e.g. heat affected zone (HAZ), recast layer conicality, are presented. During different process gases used. results velocities, thickness chemical composition melting...

The increasing pixel density in displays demand a high quality the production of Fine Metal Masks (FMMs). process FMMs boils down to structuring tiny holes thin metal sheets or foils. manufacturing requirements are precision terms hole geometry order let enough light escape from each diode and productivity produce required amount. To achieve both objectives, power Ultra Short Pulse (USP) lasers can be utilized. Since USP fall short requirements, they combined with multi-beam scanners. During...

A model for laser cutting describing the movements of two free boundaries melt will be presented. The is an asymptotic approximation a boundary problem and involves surface tension melt. stationary solution given investigated linear stability. results are illustrated with data from experiments.

The interaction of picosecond and sub-picosecond laser pulses with metals is investigated both, theoretically experimentally. Analyzing the Boltzmann equation for electrons phonons hyperbolic two-temperature model heat conduction in obtained. In particular parameter range which effects are significant analyzed. For calculations a numerical algorithm based on method lines developed. Experimentally duration 40 ps used to remove thin metal films. removal process analyzed by pump probe...

During laser fusion cutting of sheet metal parts, a focused beam is traversed relatively to the processed part.The material molten due heat input and driven out kerf by gas jet aligned coaxially with laser.The edges remaining show striation pattern which affects quality cut.The amplitude, wavelength shape these striations depend on dynamics motion thin melt film inside interaction zone.

Trepanning of 200 μm holes in 2-5mm thick CMSX-4 sheets is done by laser radiation provided a lamp-pumped Nd:YAG slab with pulse durations 100 - 500 μs. Pulse energies <1J determine the material removal mainly melt expulsion assisted processing gas jet coaxial to beam. Stagnation and deflection at entrance kerf, friction molten material, liquid/solid interface hinder an efficient expulsion. A simulation tool for supersonic flow solving Euler equations Finite Volume Method developed order...

In the field of micro- and nanostructuring multibeam ultrashort pulsed laser processing attracts increasing attention due to its ability generate periodic pattern like filters with a speed up 22.000 holes/sec. The multibeamscanner (MBS) developed at Fraunhofer Institute for Laser Technology ILT enables &gt; 200 beams in parallel precision &lt; 1 &mu;m. MBS combines latest femtosecond technology sophisticated optical concept. High is useful approach increase productivity material by means...

The industrial application of laser welding implies a reliable and efficient production process. Thus, modelling simulation is used to reveal the crucial points process described by transport phenomena for mass, momentum energy. three involved phases (solid, liquid, gaseous) interact over their free moving phase boundaries. existing boundary layer character allows reduce dimension this Free Boundary Problem. resulting model reproduces time-dependent spatially 3d-distributed Technical...

In the field of consumer electronics, especially in display manufacturing, Full Metal Masks (FMMs) with ever increasing structural requirements are needed.In addition, manufacturing technologies should meet these at high productivity.High power ultra short pulsed lasers combination a multi-beam scanner key enabler by combining precision laser tools productivity parallel processing.In order to produce FMMs required quality, temperature-related distortions due heat accumulation must be...