Motor characterization has a fundamental role in dynamics, torque accuracy, and efficiency of vector controlled Synchronous Reluctance Machine (SynRM) drives. Control performances and robustness in the whole speed/torque range, including the flux-weakening region, and in sensorless operation strongly rely on the knowledge of machine flux versus current characteristics. A convenient flux saturation approximating function is proposed in this paper, together with an efficient parameters self-identification procedure. The adopted strategy is very simple and can be performed at stand-still by injecting a proper voltage stimulus (current control is not involved), and does not require any additional hardware (motor can be either connected or disconnected from mechanical load). Nevertheless, an excellent fitting for the flux curves on both axes is obtained, using reasonable memory and computational resources. These features make the technique very suitable to motor self-identification in industrial drives. Experimental results based on a commercial drive and two SynRMs are reported to demonstrate the effectiveness of the proposal. Extensions of the method to the evaluation of the whole flux map (including cross-saturation effects) or to interior permanent-magnet machines is also investigated and verified. © 2016 IEEE

This paper deals with the flux-weakening control of surface-mounted permanent-magnet synchronous motors, taking into account the influence of the resistive voltage drop in the stator windings, whose effect is usually neglected in similar studies. First, the motor equations exploiting the optimal torque-speed limits in the flux-weakening region are evaluated and discussed. Then, the influence of the resistive voltage drop is pointed out, highlighting its effect on the setup of the flux-weakening strategy. Hence, a simplified approach to flux-weakening motor control is presented, useful for the practical implementation in microcontrolled drives. Finally, experimental results are shown, using a position tracking application as a test case. Copyright © 2010 IEEE

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This paper deals with a novel approach for the real-time tracking of the maximum-torque-per-ampere (MTPA) trajectory of an interior permanent-magnet (IPM) motor drive. The proposed approach is based on the injection of proper test signals and allows the MTPA trajectory to be learned and updated in the drive during steady-state conditions. The analytical development of the estimation algorithm, which is supported by a complete validation by simulation, is given in this paper. Finally, experimental results are presented based on a prototype IPM drive system

Precise motion control requires high-accuracy and highbandwidth feedback speed information, often calculated by direct measurement of the rotor position available through the incremental encoder equipping the drive. The resolution of the encoder heavily affects the cost of the drive and the accuracy and bandwidth of the calculated speed. The limitations introduced by a low resolution encoder can be partially reduced by a proper speed calculation (or estimation) algorithm, that therefore plays a key role in modern drive systems. In this paper a comparative analysis of state-of-art speed measurement and estimation algorithms suitable for low-resolution incremental encoder equipped drives is presented, aiming at highlighting the specific feature of each one, both from the performance point of view, and from the computational requirements needed for actual implementation. The paper proposes itself as a guide for engineers in the complex choice of the best solution for each application.