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1. (WO2018103581) METHOD AND SYSTEM FOR ESTIMATING ROTOR RESISTANCE OF INDUCTION MOTOR

Pub. No.:    WO/2018/103581    International Application No.:    PCT/CN2017/113807
Publication Date: Fri Jun 15 01:59:59 CEST 2018 International Filing Date: Fri Dec 01 00:59:59 CET 2017
IPC: H02P 21/14
Applicants: NIO NEXTEV LIMITED
蔚来汽车有限公司
Inventors: WANG, Kai
王凯
Title: METHOD AND SYSTEM FOR ESTIMATING ROTOR RESISTANCE OF INDUCTION MOTOR
Abstract:
A method and system for estimating a rotor resistance of an induction motor. The method comprises: based on a model reference adaptive system, respectively establishing a magnetic flux current model and a magnetic flux voltage model for an induction motor (S10); respectively measuring stator temperatures at a plurality of different moments (S11); determining, on the basis of enabling a phase difference between outputs of the magnetic flux current model and the magnetic flux voltage model to be zero, estimated values of a rotor resistance corresponding to the plurality of different moments on a one-to-one basis (S12); calculating a temperature ratio of a rotor temperature to a stator temperature based on a correlation between the estimated values of the rotor resistance and the stator temperatures (S13); and calculating the rotor resistance online based on the temperature ratio, a current stator temperature, a stator reference temperature, a rotor reference resistance and a rotor material (S14). In the method, various main parameters for the operation of the motor are not only taken into consideration, but also the rotor resistance can be estimated at a low speed area of the motor, thus realizing more accurate estimation of the rotor resistance, and the present invention is widely applicable, is easy to implement, and has a high execution efficiency.