Patent ID: 8415916

Claim:
A method of identifying a parameter of an induction machine when the induction machine is connected to output phases of a voltage source inverter and the induction machine is in standstill state, the method comprising: a first phase which includes: magnetizing the induction machine by providing a first DC magnetization current (i m ) to the induction machine via the inverter until the induction machine reaches steady state, a current reference of the inverter having a first value (i dc — ref1 ), controlling power semiconductors of the inverter to an off-state for a predetermined period of time (Δt), controlling all output phases of the inverter to a same potential for providing a zero voltage vector, and measuring a first maximum value (i mz — max ) of a stator current (i sd ) during the zero voltage vector; and in a second phase: magnetizing the induction machine by providing a second DC magnetization current to the induction machine for a magnetization time period (t 1 −t 0 ) via the inverter, the current reference having a second value (i dc — ref2 ) which is higher than the first value of the current reference (i dc — ref1 ), controlling the power semiconductors of the inverter to an off-state for the predetermined period of time (Δt), controlling all the output phases of the inverter to a same potential for providing a zero voltage vector, measuring a second maximum value (i sdz — max ) of the stator current during the zero voltage vector, estimating a parameter of the induction machine when the measured first and second maximum values of the stator current (i mz — max , i sdz — max ) are equal, and repeating the second phase with different magnetization of the induction machine when the first and second measured maximum values of the stator current are not equal.