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In more electric aircraft (MEA), supplying constant voltage variable frequency (CWF) AC power to frequency insensitive loads (eg. wing de-icing system, galleys, etc.) in DC primary distribution system requires an AC-DC-AC conversion which adds losses and additional hardware installment to the system. This paper presents a novel open-end winding induction generation system supplying CWF AC power for...
This paper deals with speed control of a squirrel cage six-phase induction machine (SC6PIM) in phase opening occurrences. A decoupled model of induction machine with unbalanced structure is given to analyze the phase opening operation of the SC6PIM. In order to reduce torque oscillations created in phase opening events, a fault-tolerant operation method by using indirect rotor field oriented control...
In this paper, a novel 42 slot, 20 pole ironless winding for use in an axial-flux machine is presented. The proposed design improves the utilization of the available air gap area and is based on the implementation of the winding as a printed circuit board (PCB). Besides, it is compared with a conventional 21 slot, 20 pole ironless axial-flux winding regarding the criteria: torque generation and induced...
An equivalent circuit model of a double-armature rotary-linear induction motor is proposed. The stator of the motor possesses rotary and linear-tubular armatures placed aside one another. Both armatures interact with a cylindrical double layer solid rotor which can move rotary, linearly or with helical motion. The static end effect in linear armature and the dynamic longitudinal end effects which...
Accurate simulation of electric drives has always been desirable, as it allows the machine designer a deeper insight into the whole design. It is known that a co-simulation of Finite-Element-Analysis, circuit and control simulation can give much more accurate results than conventional simulation approaches. The effects of rotor segmentation, however, cannot be accurately modeled in two dimensions...
The dual-inverter fed Open-End Winding Induction Motor drive offers interesting possibilities for multilevel inversion. It needs two isolated power supplies to feed individual inverters to avoid the flow of zero-sequence current. Three Space Vector PWM schemes have been reported in the earlier literature, which facilitate the operation of the dual-inverter drive with a single power supply. This paper...
The steady state operating curves of three design variants of a five-phase induction machine are assessed and compared to a standard three-phase induction machine of the same size which is taken as the basis for the comparison. The performance in terms of torque, power factor, stator current and efficiency are analyzed for different load conditions. The operating curves are determined by means of...
A methodology is described to conservatively predict the behavior of DC capacitor voltage for floating capacitor H-bridge converters, which are located in each phase between the utility grid and a squirrel cage induction motor. Under the proposed methodology, an algorithm is developed to predict the DC voltage level before motor starting. In this way, DC capacitor voltage overshoot problem can be...
The dynamic voltage restorers are efficient series compensation devices to improve power quality. Indeed, they are composed of a coupling transformer and power electronics to provide fast voltage sag correction and harmonics compensation. This paper focuses on a new topology of a coupling transformer for the dynamic voltage restorers which improves the protection of the voltage source converter against...
This paper presents the calculated demagnetization characteristics of different types of permanent magnet synchronous machines (PMSMs) under the influence of demagnetizing MMF contributed by the stator currents (i.e., armature reaction). The demagnetization of NdFeB magnets is quantified in terms of demagnetized magnet volume and loss of magnet remanence using finite element (FE) analysis. The impact...
The increment of the manageable power in machines where the normally adopted ferrites are replaced with bonded magnets can vary and can introduce saturation problems depending on the variations in the magnetic circuit design. The saturation of the magnetic circuit distorts the phase voltages, introducing undesired harmonics in the connection to the mains. Combined modifications of both stator poles...
This paper presents design strategies for the optimized design of the rotor poles in synchronous permanent magnet machines. The strategies are aimed at the reduction of torque ripple and cogging torque. Sinusoidally rounded magnet and rotor step-skewing are investigated, then a new proposal to reduce the cost of magnetic pole made in rare earth is presented. The goal is to introduce into a rotor pole,...
This article provides design and finite element analyses information of two possibilities of cylindrical rotor synchronous machine excitation winding designs. It is focused especially on multiple-pole synchronous machines, where the presence of higher amount of machine poles reduces amount of available slots for excitation winding, therefore all negative effects are well observable. On these topologies...
Design studies for a 10 MW superconducting wind generator have been performed for offshore wind turbine applications. Electromagnetic, mechanical and thermal analyses are performed by taking into account the characteristic properties of the superconducting and non-superconducting materials. The investigations use enhanced YBCO (Yttrium Barium Copper Oxide) second generation (2G) high temperature superconducting...
The thermal design of small squirrel cage machines is a challenge in comparison with the permanent magnets machines of the same frame size. When designing the machine, the calculated temperatures in all parts should be lower than their critical temperatures. This paper aims to perform thermal analysis for different load types in order to achieve a safe thermal design of the motor. The machine under...
This paper proposes a new cross-coupled two-degree-of-freedom (2DOF) direct drive motor which can independently realize rotary and linear motions. In this proposed motor, the mover part is a shaft with segment magnets formed in checkers. On the other hand, two sets of helical windings are cross-coupled in the stator part. The configuration can generate thrust force and torque independently. In this...
This paper presents a direct, adaptive and parameter-free current control scheme that is independent of the motor type and doesn't need any machine parameters. A given setpoint can be reached accurately within one switching cycle.
This paper discusses a direct grid connection system for the permanent magnet synchronous motor (PMSM). It is difficult to connect PMSM to the power grid directly due to the resonance between a synchronous reactance and the inertia moment. In order to solve this problem, the direct grid connection system which consists of an auxiliary inverter of small capacity and a matrix converter is proposed for...
Considering the existence of disturbance in the induction machine (IM) drive system, this paper develops a composite control scheme based on linear extended state observer (LESO) and continuous finite time control (FTC) to improve the disturbance rejection property of system. First, a LESO is introduced to estimate the disturbances of system. The estimated value is used in the feed-forward compensation...
This paper address the effect of magnet coverage on the torque, iron and magnet loss components and torque ripple of two surface permanent magnet synchronous generators of 5MW. The values of torque, torque ripple, iron and magnet losses are calculated using a FEM program. It is concluded that the optimal magnet coverage can only be found by extensive investigations for each specific machine. However,...
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