| US 7,560,894 B2 | ||
| Method and system in connection with permanent magnet synchronous machines | ||
| Janne Salomäki, Hyvinkää (Finland); and Antti Piippo, Espoo (Finland) | ||
| Assigned to ABB Oy, Helsinki (Finland) | ||
| Filed on Jun. 14, 2007, as Appl. No. 11/812,074. | ||
| Claims priority of application No. 06115523 (EP), filed on Jun. 15, 2006. | ||
| Prior Publication US 2008/0030162 A1, Feb. 07, 2008 | ||
| Int. Cl. H02P 6/00 (2006.01) | ||
| U.S. Cl. 318—721 [318/701; 318/727; 318/807] | 12 Claims |
| 1. A method in connection with a speed and position sensorless permanent magnet synchronous machine equipped with an output
filter and driven by an inverter, wherein the method comprises the steps of
forming a speed-adaptive full-order observer based on the dynamic model of the combination of the permanent magnet synchronous
machine (PMSM) and the output filter, the observer using inverter output current (iA) as the measured feedback signal and an estimate for the electrical angular speed (ωm) of the motor and a speed correction term (ωε) for adaptation of the observer,
measuring the inverter output current (iA),
estimating inverter output current (îA) using the observer,
determining the estimate for the electrical angular speed (ωm) of the machine using the estimated inverter output current (îA) and measured inverter output current (iA) in an adaptation law,
injecting a voltage signal (uc) into the inverter voltage reference (uA,ref 0) to obtain a modified voltage reference (uA,ref) that is used to control of the inverter,
detecting an error signal (ε) from the measured inverter output current (iA) originating from the injected voltage signal (uc), and
calculating the speed correction term (ωε) used in the adaptation of the observer from the error signal (ε).
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