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An online parameter identification method and sensorless control using identified parameters were realized in surface and interior permanent-magnet synchronous motors (SPMSMs and IPMSMs, respectively). As this method does not use rotor position or velocity to identify motor parameters, the identified parameters are not affected by position estimation error under sensorless control. The proposed method can be applied to all kinds of synchronous motors. The effectiveness of the proposed method was verified by experiments in both SPMSMs and IPMSMs. Index Terms--Extended electromotive force (EEMF), online parameter identification, permanent-magnet synchronous motor (PMSM), sensorless control.

A new piezoelectric piggy-back microactuator for high density hard disk drives was designed and fabricated to achieve more accurate positioning of the magnetic head and increasing the servo bandwidth. The microactuator is made of stiff piezoelectric ceramic material to actuate the slider on which the head-element is formed. It is designed to amplify the actuating displacement. The basic mechanical performance of the microactuator was evaluated. The stroke of displacement was [+ or -]0.5 [[micro]meter] with a drive voltage of [+ or -]10V and a dc bias of +10V. The resonant frequency of the microactuator was high at 34 kHz. The fundamental resonant frequency of an assembled head with microactuator was high at around 20 kHz. The head variation was suppressed to 0.1 [[micro]meter] by the microactuator with feedback control. These results suggest the feasibility of increasing servo bandwidth up to several kHz and positioning the head more precisely.

N-(fluoroethyl)amines undergo anodic methoxylation with the methoxy group introduced into the position alpha to the fluoromethyl (Rf) group, which is influenced by the R and Rf groups. The alpha-CH kinetic acidities of the cation radicals which result from the one-electron oxidation of the amines account for the regioselectivity and promotion effect of the alpha-methoxylated amines. Carbon-carbon bonds alpha to fluoroalkyl groups can be formed using methoxylated amines as fluoro building blocks.

A sensorless control method based on novel extended electromotive force (EEMF) models considering magnetic saturation is proposed for synchronous reluctance motors (SynRMs). Since motor parameters, particularly inductances, vary largely in SynRMs, a precise sensorless control is necessary for fully considering such variations. In this paper, the EEMF model, taking into consideration magnetic saturation, is derived and is applied to a position estimation method. The two EEMF models caused by a difference in the d-axis direction are shown, and the appropriate EEMF model that can suppress a position estimation error caused by the deviation of inductance parameters is proposed. Moreover, an online parameter identification method for sensorless control in middle- or high-speed ranges is proposed. The necessity for the use of the model, taking into consideration magnetic saturation, is verified by experiments. The proposed sensorless control system is shown useful by experiments. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new mathematical model for synchronous motors and a sensorless control method based on it. To control permanent magnet synchronous motors, knowledge of rotor position and velocity are necessary. Heretofore, expensive sensors have been used to detect rotor position information. Although many sensorless control methods based on the electromotive force (EMF) have been developed for non-salient-pole permanent magnet motors, they cannot be applied for salient-pole motors without approximation because of complications in the mathematical model; this is turn may lead to problems of instability. To solve this problem, we propose an extended electromotive force model for synchronous motors. The proposed model has a simple structure, making position estimation possible without approximation. Experimental results show that the proposed model and method are valid. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(3): 55–64, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10257 [ABSTRACT FROM AUTHOR]

Examines the anodic methoxylation of N-(fluorethyl)anilines and N-aryl-N-(fluoroethyl)amines to determine the scope of these reactions. Preferential introduction of methoxyl group into the position alpha to the fluoromethyl(trifluoromethyl, difluormethyl or fluormethyl) group; Promotion effect and regioselectivity due to alpha-kinetic acidifies of cation radicals.