Model Based, Direct Flux Vector Control of Permanent Magnet Synchronous Motor Drives

This paper proposes a direct flux vector control strategy with no need for regulators tuning, suitable for permanent-magnet (PM) synchronous machine drives. The controller operates in stator flux coordinates and calculates the inverter reference voltages in a model-based fashion, taking advantage of a novel equation for the explicit evaluation of the torque angle error. The inverter current and voltage limits are exploited in a parameter-independent way. The method segregates the machine parameters into a single block, to make it very easy to switch from one machine to another. Experimental results are reported for a PM-assisted synchronous reluctance motor drive example, characterized by significant saturation and cross-saturation. State-of-the-art control techniques such as current vector control and non-model-based direct flux vector control are also considered, for the sake of comparison, in simulations and experiments

Plug-in, Direct Flux Vector Control of PM Synchronous Machine Drives

A general-purpose control algorithm is proposed for permanent-magnet (PM) synchronous machine drives based on the principle of direct-flux vector control. The algorithm does not require regulator tuning, and it is tailored to different machines automatically via identification of the stator resistance and flux linkage tables. The model parameters are identified via a preliminary self-commissioning procedure that can be integrated into the standard drive firmware with no need for extra hardware or offline manipulation. The combination of the control and self-commissioning algorithms forms a “plug-in” controller, which pertains to a controller that is capable of exploiting the full drive capabilities with no prior knowledge of the PM machine in use. Experimental results are reported for two prototype concentrated-winding PM machines designed for traction applications, i.e., one with a surface-mounted PM rotor and another with an interior PM rotor

Multipolar SPM machines for direct drive application: a general design approach

A closed-form, per-unit formulation for the design of surface mounted permanent magnet motors having high numbers of poles is hereby proposed. The analytical expression of machine inductances is presented, covering distributed and concentrated windings configurations. The paper addresses how the slot/pole combination, the geometric variables and the number of poles are related to average torque, the Joule loss and the power factor. The performance of distributed and concentrated windings machines is compared analytically, in normalized quantities. Last, the design approach is tested on four design examples, including all winding types and validated by finite element analysis

Magnetic Model Self-Identification for PM Synchronous Machine Drives

The Magnetic Model Self-Identification of PM Synchronous machines is proposed and experimentally validated. Provided that the shaft is free to turn, the commissioning procedure consists of spinning the machine to positive and negative speed values by way of an appropriate pattern of dq current reference values. The flux linkage versus current curves of the machine are constructed during the test via the standard measurements available on any industrial drive: phase currents, dc-link voltage and shaft position. Respect to the literature, the proposed method does not require a specific test rig nor off-line mathematical manipulation