235 research outputs found
Influence of machine topology and cross-coupling magnetic saturation on rotor position estimation accuracy in extended back-EMF based sensorless PM brushless AC drives
The influence of the machine topology and dq-axis cross-coupling on the rotor position estimation error in an extended back-EMF based sensorless brushless AC drive is investigated by both finite element analysis and experimentally on four brushless AC machines having different rotor topologies, viz. interior circumferentially magnetized, interior radially magnetized, surface-mounted, and inset magnets. The d- and q- axis apparent self- and mutual-inductances, Ld, Lq, Ldq and Lqd, are predicted by finite element analysis for various d- and q-axis currents. The error in the estimated rotor position of the four machines is investigated and compared when (a) the influence of magnetic saturation is neglected, (b) only the influence of the dq-axis current on Lq is considered, but dq-axis cross-coupling magnetic saturation is neglected, and (c) the influence of dq-axis cross-coupling magnetic saturation is taken into account. It is shown that the error is more strongly influenced by the q-axis current/permeance than the dq-axis current/permeance, since the dq-axis current does not distort the symmetrical field distribution about the q-axis, and that dq-axis cross-coupling magnetic saturation can significantly affect the accuracy of the rotor position estimation. However, by introducing an apparent mutual winding inductance in the extended back-EMF based sensorless method, the error in all four machines under consideration is reduced significantly, to a similar level to that which results with surface-mounted magnet machines
Otter Realm, November 1997, Vol. 2 No. 18
Panetta Lecture Series Gets Underway -- First Annual Hunger Awareness Week -- Student Voice-news and issues -- Self-defense class to be offered -- IMIE learners rub shoulders with multi-millionaires -- Horoscopes -- CSUMB Student Brings the Cheetah to Children -- Hands-On Experiments Highlight First Annual Girls\u27 Science and Math Conference -- CSUMB Cross-country team to host Turkey Trot and College Invitational -- Otter golf champions continue winning ways -- Regatta draws competitive field to Monterey Bayhttps://digitalcommons.csumb.edu/otterrealm/1022/thumbnail.jp
The Need for Urban Animal Control
The relationship between humans and animals has evolved over many centuries; in the beginning it was very violent. As humans moved from a cave to a village and later to a farm, they protected their property with whatever means were available. Spears, traps and later poisons and rifles were used to handle wildlife problems. As methods of providing life\u27s necessities were refined, people moved from the farms into the cities. Today, many former city dwellers are moving out of town into a more rural setting. Although the relationship between wildlife and humans has changed from its violent beginnings, competition still exists - it is just less dramatic
A Power Struggle of Mythic Proportion: In the World of ERISA are Retirement Plan Administrators the Real Gods of Olympus?
FACULTY AND GUEST ARTIST RECITAL CURTIS MACOMBER, violin (guest) JOSEPH MAILE, violin JAMES DUNHAM, viola NORMAN FISCHER, cello JEANNE KIERMAN, piano Wednesday, September 24, 2008 8:00 p.m. Lillian H. Duncan Recital Hall
Istanbul festival is in its 15th year
Taha Toros Arşivi, Dosya No: 131-İstanbul Festivaliİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033
Sub-diffraction control of the height and fluorescence of the 3D structures fabricated with direct laser writing (DLW) lithography
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