Patent Number: 7,102,325

Title: Method for determining rotor flux vector of AC electrical machine

Abstract: A method for determining the rotor flux vector of an electrical machine, the method comprising the steps of controlling the electrical machine with an inverter, forming an equation for the reactive power (Q.sub.inv) at the output of the inverter, forming an equation for the consumed reactive power ({circumflex over (Q)}.sub.mot) in the electrical machine, forming a reactive power balance equation (Q.sub.err) between the reactive power (Q.sub.inv) at the output of the inverter and the reactive power ({circumflex over (Q)}.sub.mot) consumed in the electrical machine, determining the stator resistance ({circumflex over (R)}.sub.s) of the electrical machine from the balance equation (Q.sub.err), determining the stator flux estimate ({circumflex over (.psi.)}.sub.s) using the determined stator resistance ({circumflex over (R)}.sub.s) and the balance equation (Q.sub.err), and determining the rotor flux estimate ({circumflex over (.psi.)}.sub.R) using the determined stator flux estimate ({circumflex over (.psi.)}.sub.s).

Inventors: Vertanen; Mikko (Espoo, FI)

Assignee: ABB Oy

International Classification: H02P 23/00 (20060101)

Expiration Date: 9/05/02018