Position estimation delays in signal injection-based sensorless PMSM drives

The causes of position estimation delays and their effects on the sensorless control of permanent magnet synchronous motor drives are investigated. The position of a permanent magnet synchronous machine is estimated via the injection of high frequency voltage signals. The delays under investigation are due to the digital implementation of the control algorithm and to the digital filters adopted for decoupling the inspection signals from the fundamental components of the stator current measures. If not correctly modeled and compensated, such delays can reduce the performance of the control scheme. Experimental results are provided, proving the accuracy of the modeling approach and the effectiveness of the related compensation strateg

Accurate Inverter Error Compensation and Related Self-Commissioning Scheme in Sensorless Induction Motor Drives

This paper presents a technique for accurately identifying and compensating the inverter nonlinear voltage errors that deteriorate the performance of sensorless field-oriented controlled drives at low speed. The inverter model is more accurate than the standard signum-based models that are common in the literature, and the self-identification method is based on the feedback signal of the closed-loop flux observer in dc current steady-state conditions. The inverter model can be identified directly by the digital controller at the drive startup with no extra measures other than the motor phase currents and dc-link voltage. After the commissioning session, the compensation does not require to be tuned furthermore and is robust against temperature detuning. The experimental results, presented here for a rotor-flux-oriented SFOC IM drive for home appliances, demonstrate the feasibility of the proposed solution

A SyR and IPM machine design methodology assisted by optimization algorithms

The design optimization of synchronous reluctance (SyR) machine and its extension to internal permanent magnet (IPM) motors for wide speed ranges is considered in this paper by means of a Finite Element Analysis-based multi-objective genetic algorithm (MOGA). The paper is focused on the rotor design, that is controversial key aspect of the design of high saliency SyR and IPM machines, due to the difficult modeling dominated by magnetic saturation. A three step procedure is presented, to obtain a starting SyR design with the optimal torque versus torque ripple compromise and then properly include PMs into the SyR geometry, given the desired constant power speed range of the final IPM machine. The designed rotors have been extensively analyzed by computer simulations and two SyR prototypes have been realized to demonstrate the feasibility of the design procedur

FEA-based multi-objective optimization of IPM motor design including rotor losses

The design optimization of IPM motors for wide speed ranges is considered in this paper by means of a FEAbased multi-objective genetic algorithm (MOGA). The minimum number of simulations is pursued for the fast evaluation of four goal functions: maximum torque, minimum torque ripple, maximum flux weakening capability and minimum rotor harmonic losses. The paper is focused on the rotor design, that is the most controversial aspect of IPM design due to the difficult modeling dominated by magnetic saturation. Three original results are presented: the elimination of higher order torque ripple harmonics and the minimization of FEA evaluations by means of a random rotor position offset and the evaluation, by means of the same static FEA runs, of the eddy current losses in the rotor core

Barriers shapes and minimum set of rotor parameters in the automated design of Synchronous Reluctance machines

The rotor design of Synchronous Reluctance machines is considered in this paper, based on a multi-objective, genetic optimization algorithm and finite element analysis. Three different types of barrier geometries are compared, all described by a limited set of input variables. The aim of the paper is to investigate the relationships between the obtainable performance and the different barrier types. The two questions underlying this analysis are: which is the geometry that can potentially give the machine with the highest torque to volume ratio? Which is the geometry with the best compromise between number of input parameters (i.e. computational time) and performance? The results of the analysis show that Synchronous Reluctance machines can be designed using artificial intelligence in a reasonable time, obtaining adequate performances and rotor geometries consistent with the literature

Design of synchronous reluctance machines with multi-objective optimization algorithms

The design optimization of synchronous reluctance (SyR) machines is considered in this paper by means of a Finite Element Analysis-based multi-objective optimization algorithm (MOOA). The research focuses on the design of the rotor geometry which is the key aspect of SyR machines design. In particular, this digest analyzes the performance of several popular MOOAs and the impact of their settings on the quality of the final design. A procedure to minimize the computational burden of the optimization process is introduced and applied for the first time to a five layer rotor. A rotor prototype has been realized to demonstrate the feasibility of the design procedur

Acceptability and Feasibility of Web-based Diabetes Instruction for Latinos with Limited Education and Computer Experience

Introduction: The internet offers an important avenue for developing diabetes self-management skills, but many Latinos have limited experience with computer-based instruction. Objective: To evaluate the feasibility and acceptability of delivering a web-based diabetes education program in a computer classroom for Spanish-speaking Latinos. Methods: Spanish-speaking Latinos (n=26) attended two classroom sessions to learn computer skills while navigating a web-based diabetes education platform. Diabetes knowledge was assessed before and after the intervention; structured interviews were completed to assess program acceptability. Results: Half of participants (50%) had not previously used a computer. Post-intervention, diabetes knowledge improved significantly (p=.001). The majority of participants (86%) indicated a preference for web-based instruction as a stand-alone program or as an adjunct to traditional classroom training, particularly citing the advantage of being able to engage the material at their own pace. Conclusion: With limited support, Latinos with minimal computer experience can effectively engage in web-based diabetes education