Dynamic motor parameter identification for high speed flux weakening operation of brushless permanent magnet synchronous machines

Abstract

An experimental investigation is conducted to determine the behaviour of brushless PM synchronous machine parameters in the high speed flux weakening operating range. Real-time operating characteristics are determined for two commercially available 4 N•m interior PM synchronous machines. Special computer assisted measuring techniques are employed using an experimental vector controlled drive, capable of providing sinusoidal excitation waveforms at up to 8000 rpm. Perturbation analysis is performed on the measured data and results are applied to a variation of the classical d-q axis equivalent circuit model. The experimental results are repeatable and show a significant variation in the machine parameters as a function of the torque angle. Magnetic non-linearities are also identified and accounted for through recomputation of the machine model over a wide range of operating points. The authors demonstrate that all tests can be performed with no previous knowledge of manufacturer proprietary information or results from finite element simulation.

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

“…Thus, (15) can be simplified to be (16 devices and are different in various systems while the sign of i q depends on the operating mode of the machine. Thus, the sign of i d is the only term can be changed for achieving the optimal efficiency of minimizing the estimation error, which can be determined by using error analysis.…”

“…For example, the methods presented in [14] and [15] propose to add a load test to aid the rotor flux linkage estimation and it is effective if the torque is accurately measured. In addition, since it is much cheaper to bury a thermocouple in stator winding than to add a torque transducer, the method in [16] proposed to monitor the variation of rotor flux linkage with the assistance from the measured stator winding temperature.…”

Dynamic parameter torque control of high speed sinusoidal flux permanent magnet synchronous machines

“…The voltage limit ellipses obtaibed from (8) take on the form shown in Figure 6. An increasing machine speed produCes a smaller voltage limit ellipse.…”

“…7 shows the effects of utilizing the dynamic machine model component information. Equations Comparison of maximum torque per ampere trajectories models maximum torque per ampere trajectory for the 3 hp sinusoidal flux permanent magnet synchronous machine under investigation in [8]. An additional trajectory was calculated using the followkg static approximations for the component values of the test machine:…”

“…The purpose of this paper is to propose a new method of torque control that cam be implemented with a sinusoidal current controlled voltage source inverter drive d d used with sinusoidal flux permanent magnet synchronous machines in the high speed operating range. This new method utilizes the dynamic machine model component values identified in [8] to provide improved torque control along a dynamic parameter cui~ent vector control trajectory. It also provides continuous control through the critical regions produced as the flux paths of the machine alter during extended flux weakening in the high speed operating region.…”