Enhanced Speed and Current Control of PMSM Drives by Perfect Tracking Algorithms

Abstract-Speed and current closed loops control represent the heart of any advanced AC servo drive. These inner loops usually feature high-dynamic feedback control, with possible axes decoupling and a straight feedforward action of the backelectromotive force (back-EMF). More sophisticated techniques as single-rate or multi-rate control could be exploited for both speed and current closed loops, and their performances compared to that of the classic cascade feedback controllers. This represents the goal of the present work, focusing on permanent magnet synchronous motor (PMSM) drives

Permanent magnet synchronous motor drives

The use of PMSMs is widespread and the related power electronic control has reached a good maturity. New hybrid (reluctance and PM) motor topologies are studied to provide motors with improved efficiency and self-sensing features. The use of these motors complicates the control algorithms and makes the availability of complete and reliable magnetic model unavoidable. Therefore, the modelling of complex system will probably take a large part of research activity in the field. Further technology steps will be the use of more powerful computing devices, as FPGAs, that in turn will smooth the way for both the direct voltage measurement and a more sophisticated signals filtering. Finally, the emerging energy awareness Permanent magnet synchronous motor drives is going to draw new paradigms, based on multi-variable control, for the contemporary optimisation of different power electronics and drive aspects. In perspective, the best candidate is the MPC, as soon as its online implementation will become technically feasible

A Force feedback System for Steer-by-Wire Applications Based on Low-Cost MR Fluids

In the automotive research scenario, the main purpose of a steer-by-wire system is the elimination of all mechanical connections between wheels and the steering wheel. The driver gets just a virtual and configurable feedback through the steering wheel, which becomes a stand-alone component. Among the emerging alternatives, magnetorheological (MR) fluids exhibit interesting properties that could well fit for safe and reliable force feedback systems. Through the collected data, this paper offers the essential information for the realisation of a force feedback device for steer-by-wire application. The paper includes the design and test of a pre-industrialised system, exploited for the measurements of low-cost, homemade MR fluids. Experimental results and their discussion conclude the paper

Identification of mechanical load for electrical drive commissioning - labelling machine case study

The paper presents a result of the system identification theory applied to an industrial machine. The case study was a labelling machine driven by a permanent magnet synchronous motor drive. The identified system model has been used to tune the closed-loop speed control of the drive. A brief recall of the basic principles of power spectral density applied to model identification, hints for the practical implementation and experimental results are included in the paperQC 20181001</p

Full-Digital Predictive Hysteresis Current Control for Switching Losses Minimisation in PMSM Drives

In this paper a novel hysteresis current control is proposed. It is based on a simplified predictive algorithm that somewhat recalls those used in the direct torque control drives. The two major features are the sensible reduction of inverter switches commutations and the full-digital implementation based on look-up tables. The proposed algorithm has been implemented as inner loop of a speed control for a permanent magnet synchronous motor (PMSM). The result has been a low-cost, efficient and reliable PMSM drive, with good overall dynamic performance. The paper reports both simulation and experimental results, carried out on a laboratory prototype

Hardware and software effective configurations for multi-input fuzzy logic controllers

This paperr proposes two novel approaches to the simplification of multi-input fuzzy logic controllers (FLC\u2019s). By these approaches either a hierarchical or a parallel structure is derived for a multi-input FLC, leading to the implementation of faster controllers with reduced memory demand. Both these features can be used profitably in the realization of hardware and software effective FLC\u2019s for the industrial field applications. Experimental tests and comparative considerations are also included in the paper

FPGA-based voltage measurements in AC drives

In the modern sensorless and self-commissioning drives scenario, the availability of precise phase voltage measurement represents an undoubted advantage. But the task is not trivial, and few viable solutions are available. The present paper proposes an up-to-date digital method for the measurement of the instantaneous phase voltages of a three-phase PWM inverter. The phase-to-phase PWM inverter voltages are oversampled with respect to the switching period by fast A/D converters, which feed the FPGA-based digital integrator. The digital output is ready for further uses in any advanced control and estimation algorithm. Measurement repeatability, reduced size, tuning-free circuit are among the inherent side-advantages of the FPGA-based solution with respect to the existing analog ones. The paper includes design hints and a full batch of experimental tests and validations.QC 20180921</p

Realizzazione 'low-cost' di controllori in logica fuzzy

Il presente lavoro si prefigge \ue8 un esempio per chi per la prima volta affronta le tematica dell'applicazione della Fuzzy Logic a casi pratici di regolazione e controllo; la semplicit\ue0 della trattazione non intende dunque essere riduttiva nei confronti delle potenzialit\ue0 della logica Fuzzy, che invece sta incontrando pareri sempre pi\uf9 entusiastici soprattutto in applicazioni di notevole complessit\ue0. Dopo una breve descrizione del sistema, il lavoro descrive il progetto e la realizzazione di un controllore Fuzzy impiegando il microcontrollore ST6 prodotto dalla SGS-Thomson Microelectronics e sfruttando il pacchetto software fornito assieme all'ST6, denominato Fuzzy TECH. Vengono infine presentati i risultati ottenuti sperimentalmente ed il loro confronto con i risultati ottenuti da altre due realizzazioni dello stesso controllore effettuate con sistemi diversi

A novel fuzzy knowledge based flux observer for induction motor drives

The paper deals with the estimation of the air gap flux amplitude of an induction motor fed by a voltage source PWM inverter. The estimation is carried out by a fuzzy knowledge based (FKB) observer which infers the flux level from easily measurable quantities as the stator frequency, the stator current amplitude and the power factor as well as from the shape of the peak-to-peak value of the current ripple due to the PWM switching. Actually it has been found that the current ripple is rich in information about the saturation level of the motor iron core and therefore about the magnitude of the air gap flux. The use of a FKB observer, which is the key feature of this work, allows an effective use of such information, yielding a quite accurate flux estimation, in spite of the uncertainty in the motor parameters and of the nonlinearity due to the iron saturation

Automatic Parameter Identification of Inverter-Fed Induction Motors at Standstill

As a step towards the self-commissioning of the next generation of AC drives, the work deals with an automatic procedure for the identification of the inverse-Gamma equivalent circuit of inverter-fed induction motors (IM) at standstill. The algorithm, cut out for the modern microprocessors, combines different test signals with the aim of extracting and mapping the magnetic model non--linearity. As a key feature, the procedure uses the existing inverter as a precise voltage probe, to get the complete parameter set usually required by the advanced control of AC drives. The theoretical investigations are supported by experimental results, and reported in the paper. A distinguished characteristic of the proposed method among the other existing solutions is the accuracy of the results, confirmed by the comparison with finite-element analysis tools, tailored to the laboratory IM prototypes