The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This publication provides the process for obtaining self-inductances of electrical machines with a dependence on frequency and amplitude of an applied alternating current and consideration of a non-linearity and saturation effects in the equivalent circuit lumped parameter model that would have the same frequency and time domain characteristic as some desired investigated electrical machine. The values...
This paper presents and investigates an improved 3D-excited hybrid claw pole alternator. The new alternator design is achieved by adding two axial PM rotor components on the lateral sides of the main claw-pole rotor. These additional rotor components are located under the endturn regions of the stator winding. Therefore, the complete machine space including the end-winding region can be utilized to...
Recent investigations on IMs with FSCWs show that, due to the higher MMF harmonic content of concentrated windings, this machine type is characterized by low torque capability and quality, as well as, low efficiency and thermal problems. This paper presents a new fundamental wave FSCW with sinusoidal MMF waveform and a non-overlapping winding arrangement. The proposed winding solution consists of...
Our previous conference report on this instrument emphasized its use for fast-neutron imaging spectroscopy. We describe here its additional measurement capabilities, namely active interrogation, time-correlated pulse-height multiplication measurements, and gamma imaging.
For the recently presented "Stator Cage Machine" an analytical calculation method is developed. First of all the magneto-motive force produced by the stator is analyzed and a definition for the number of phases of such machines is given. Following, parameters of the machine (resistance, inductivity and flux linkage) and the generated torque are calculated. As the machine does not contain...
In this paper, the effects of a high temperature storage on phase inductance, ohmic and iron losses and coil quality of the stator windings are investigated. For better significance, 19 stators with different impregnation materials and methods are tested on Arrhenius basis for a useful life of 8000 hours. The results clearly show that, although the insulation resistance and phase-to-ground dissipation...
Due to the fact of a simple and robust cross-section design switched reluctance machines are perfectly suited to drive hydraulic pumps; either as a dry-running version or as a canned version for seal-less applications. The setup of the test bench is given as well as the performance (torque, losses, and efficiency) of both versions are analyzed and compared to each other. Both motors have the same...
Our research group has been developing a fast neutron imaging platform to enhance the capabilities of emergency responders in the localization and characterization of special nuclear material. This mobile imager of neutrons for emergency responders (MINER) is a compact neutron scatter camera optimized to provide omni-directional (4-Pi) imaging with only a ~twofold decrease in sensitivity compared...
Ideally, improvements of the manufacturing process do not cause deteriorations of the product characteristics. Pre-wound coils for electrical machines with concentrated windings are such an improvement. The easiest way to enable the assembling of pre-wound coils is simply the absence of pole shoes. This paper discusses the absence of pole shoes based on a sample machine. The focus lies on changes...
This paper suggests a possible explanation to the geometry-dependence of core loss by solving Maxwell's equations for the flux distribution inside a magnetic conductor carrying eddy currents. The solution reveals a displacement of flux towards the edges of the magnetic sheet. Core loss with and without the displacement effect are compared for the tooth of a highly excited and high-frequency electric...
This paper presents new cooling methods for permanent magnet synchronous machines (PMSM) with flux barriers. For a vehicle powertrain application the permanent magnet synchronous machines is a very popular choice, because of high power density, a high efficiency and the small package. However, this machine is susceptible to suffer insulations failures of coils and demagnetization of magnets under...
Novel fractional slots tooth concentrated windings often consist of several winding systems. This structure allows creating good MMF distributions with low space harmonic contents. A good example is the combined wye-delta winding. Methods presented in this paper allow additional optimization steps in already designed electric machines containing the combined wye-delta winding even with fixed number...
In this paper, a system of coupled and interacting models for dynamic electric and thermal behavior of an electrical machine is presented. The models are specifically designed for maximum execution speed and are suitable for simulating the machine behavior over long time periods and even the entire lifetime of the machine. Nevertheless, the results proved to be remarkably accurate. Arbitrary electrical...
The purpose of this paper is the design of different switched reluctance drives for an existing drive train of an electromechanical actuation system of a small unmanned aerial vehicle. Therefore, the outside dimensions of the switched reluctance machine are determined by the used permanent magnet synchronous motor size to allow the easy exchange of the motor drives. Moreover, the switched reluctance...
The relationship between impregnation process and winding temperature has not been analyzed in detail yet. Therefore, one purpose of this paper is to investigate the correlation between impregnation process, resin absorption, applied resin, and thermal behavior. Apart from thermal behavior, it has to be ensured that the lifetime of the manufactured electrical machines still meets industrial specifications...
This paper proposes a predictive control strategy for the voltage stability of brushless excited synchronous generator for the aircraft power system using dead-beat control. The synchronous generator is coupled to the aircraft engine and it delivers the power to 270VDC bus via a 12-pulse diode bridge rectifier. Due to the speed variations of the aircraft engine, the brushless excitation is used so...
We are developing Hermes-III at Sandia National Laboratories as a pulsed bremsstrahlung test-bed for active interrogation for fissionable materials detection.1 Photons generated by an electron beam striking a Ta converter propagate to a target location 19 m from the electron beam diode, at which various materials are placed. X-rays produce (g, f) and (g, n) reactions in fissionable material, while...
The fractional slots tooth concentrated windings are characterized with high space MMF harmonics which results to undesirable effects on electric machine. A novel and high efficiency method is presented in this paper to reduce simultaneously the sub- and high MMF harmonics of these winding types. Using this technique, a new 18-teeth/10-poles PM machine for traction applications is designed and their...
This paper presents a new cooling approach for traction motors which are mounted in hybrid electric vehicle (HEV) or battery electric vehicle (BEV). For this vehicle powertrain application the permanent magnet synchronous machines (PMSM) is a very popular choice, because of high power density, a high efficiency and the small package. However, this machine is susceptible to suffer insulations failures...
In this paper, an analytical model to calculate a canned switched reluctance machine (SRM) is presented. Such a model is characterized by a multilayer structure in a cylindrical coordinate. Maxwell's equations are used to derive the magnetomotive force (MMF) distribution of the stator armature and determine the arrangement of wires within a coil. The large rotor and stator slots of double saliency...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.