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This paper proposes a novel flux-weakening control algorithm of an interior permanent-magnet synchronous motor for ldquoquasirdquo six-step operation. The proposed method is composed of feedforward and feedback paths. The feedforward path consists of 1-D lookup table, and the feedback is based on the difference between the reference voltage updated by(More)
This paper describes the strategy to design and control an axial-flux (AxF) surface-mounted permanent-magnet machine for achieving a wide flux-weakening (FW) operating region. By using a slotted stator with fractional-slot windings and additional cores enclosing end windings, the AxF machine satisfies the specification of a wide constant-power speed range.(More)
This paper proposes a novel antiwindup method of current regulator for the drive system of a surface-mounted permanent-magnet synchronous motor at flux-weakening region. It is designed in conjunction with the synchronous-frame proportional and integral current regulator and the space vector pulse width modulation. The difference between the regulator output(More)
This paper shows several structures of the hybrid excavator with the supercapacitor and compares them with each other from the aspect of fuel efficiency, the additional cost due to the hybridization, and the expected payback time. According to the comparison result, it can be concluded that a compound-type hybrid structure is a better solution than others(More)
This paper describes a novel identification technique of the moment of inertia and the viscous friction coefficient for a servo drive system. It is developed based on the basic dynamic equation of a mechanical system, and it uses the torque reference of a speed controller and the actual rotating speed of machine for the identification. Regardless of the(More)
In this study, the permeability of passivation layers consisting of aluminum oxide (Al2O3) and titanium oxide (TiO2) was examined. The films were deposited on poly(ether sulfone) (PES) substrates via electron cyclotron resonance atomic layer deposition (ECR-ALD) at various deposition temperatures. The optimum plasma power and deposition temperature were(More)
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