Patent Number: 6,429,616

Title: Method of estimating the DC bus voltage in electric machine drives

Abstract: An electric machine drive system uses an estimation of the DC bus voltage to improve machine drive control. The DC bus voltage is estimated by injecting a carrier signal into the machine drive and determining the magnitude of the positive sequence current component induced in the drive by the carrier signal. The measured magnitude of current may be referenced to the anticipated magnitude of the current in order to produce an inverse value of the estimated DC bus voltage that is then used to normalize the commanded voltage signal driving the machine. Alternatively, a look-up table is used to relate the measured magnitude of the current component to a corresponding estimated value of the bus voltage.

Inventors: Myers; Garold Paul (Northville, MI), Degner; Michael W. (Farmington Hills, MI), Harke; Michael (Madison, WI)

Assignee: Ford Global Technologies, Inc.

International Classification: B60L 11/18 (20060101); H02P 27/04 (20060101); H02P 27/06 (20060101); H02P 007/06 ()

Expiration Date: 08/06/2010