Fast estimation and compensation of rotor flux linkage in permanent magnet synchronous machines

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

“…Since the rotor PM flux linkage decreases as the PM temperature increases, it is desirable to estimate the rotor flux linkage value no matter it is for torque control/monitoring or for prevention of PM demagnetization. For example, it is proposed in [37] that the influence from the variation of rotor flux linkage on the computed torque in direct torque control can be compensated by online estimation of rotor flux linkage, in which the accuracy of torque control is significantly improved. In addition, it is reported in [9] that the state of rotor permanent magnet can be monitored instantaneously by using a rotor flux linkage estimator, and a warning signal can be given if magnet demagnetization happens.…”

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

“…Taking Motor2 as an example, the estimated value of iron loss versus copper loss at full load by using SPEED software is 26% and is not negligible. Furthermore, by taking into account the core-loss resistance, (9) will become (C.2).…”

“…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. Taking the method presented in [8] as an example, it proposed to inject alternating d-axis current to activate the winding resistance and rotor flux linkage estimation.…”

Overview of condition monitoring and operation control of electric power conversion systems in direct-drive wind turbines under faults

“…In Ref. [51], a reactive power feedback method is employed to compensate for torque ripple caused by flux linkage. However, these methods only consider flux amplitude fluctuation, and the flux linkage wave of the amplitude jump is given.…”

“…The method can respond to the changing flux linkage, but it can only observe fluctuations in the flux amplitude in a fixed direction [49] An improved back-EMF method was proposed. The method can be used to estimate the flux linkage, but it can only observe the fluctuations in the flux amplitude in a fixed direction [51] A reactive power feedback method to compensate for the torque ripple caused by flux linkage was proposed. However, the method can only consider the fluctuations in the flux linkage amplitude…”