A Remote and Sensorless Stator Winding Resistance Estimation Method for Thermal Protection of Soft-Starter-Connected Induction Machines

Online Estimation of the Rotor Flux Linkage and Voltage-Source Inverter Nonlinearity in Permanent Magnet Synchronous Machine Drives

“…Thermocouples are employed for measuring the temperature variation in stator winding in order to obtain the actual value of stator winding resistance, which is used for aiding the estimation of rotor flux linkage afterwards. Thus, this method does not need to inject any signals such as i d ≠0 [1]- [5] and DC voltage pulse [10]- [14] or change the PMSM working condition [6]- [9]. Furthermore, it is advanced that the accuracy of proposed rotor flux linkage estimation will not suffer from the variation of dq-axis inductances and has taken into account the compensation of estimation error due to VSI nonlinearity thanks to the proposed V dead estimator, which does not need any device information of the VSI and PM machine.…”

“…V dead can be estimated from d-axis equation by using (10). Since the winding resistance R is a linear function of winding temperature, two sets of thermocouples are buried into two different sides of PMSM stator winding and the actual value of winding resistance can be computed by the measured average temperature through (12).…”

“…Thus, the estimation of stator winding resistance should be together with or prior to the estimation of rotor flux linkage [10]- [17], [44]- [46]. Otherwise, the estimation will face the rank-deficient problem and the accuracy of the estimated rotor flux linkage will suffer from the mismatched stator winding resistance value used in the estimator [1].…”

Parameter Estimation for Condition Monitoring of PMSM Stator Winding and Rotor Permanent Magnets

“…Thus, the winding resistance and rotor flux linkage should be estimated simultaneously and the rank deficient problem should be solved prior to the estimator design. To overcome this rank deficient problem, perturbation signals such as i d ≠0 and DC voltage offset are injected into the system to build a full rank reference model for estimation [7]- [13], [22]. It is firstly reported in [7]- [9] that by setting the dq-axis inductances to be their nominal values, the dq-axis equation can be made full rank for simultaneously estimating the winding resistance and rotor flux linkage with the injection of i d ≠0, in which the variation of inductance and non-ideal voltage measurement such as the inverter nonlinearities, the variation of DC bus voltage and zero shift in the amplifier, are not taken into account.…”

“…However, it did not take into account the influence from non-ideal voltage measurement. In addition, it is also reported in [11]- [13] that it is possible to online estimate the winding resistance by transiently superimposing a DC voltage offset in one or more of the machine phases, by which the estimation of winding resistance will be dependent of the variation of inductance and rotor flux linkage. This kind of method [11]- [13] should take into account the influence of injected DC voltage offset on the system stability and the amplitude of injected DC bias should be minimized.…”