Reducing the sampling frequency for the control of the switched reluctance machine

This paper presents two solutions for dramatically reduce the sampling frequency and therefore the CPU demand while keeping the same performance in terms of torque ripple and efficiency on a SRM. The problem of a low sampling frequency with a regular control is first highlighted. Then, two different solutions are proposed for the self switching's function. Such solutions tries to magnetize the stator phase at an accurate instant in order to reduce the inherent torque ripple. Simulations results on a 8/6 SRM corroborate the validity of the proposed solutions and show the improvements of its performance.Peer ReviewedPostprint (author’s final draft

A Novel PMSM Hybrid Sensorless Control Strategy for EV Applications Based on PLL and HFI

In this paper, a novel hybrid sensorless control strategy for Permanent Magnet Synchronous Machine (PMSM) drives applied to Electric Vehicles (EV) is presented. This sensorless strategy covers the EV full speed range and also has speed reversal capability. It combines a High Frequency Injection (HFI) technique for low and zero speeds, and a Phase-Locked Loop (PLL) for the medium and high speed regions. A solution to achieve smooth transitions between the PLL and the HFI strategies is also proposed, allowing to correctly detect the rotor position polarity when HFI takes part. Wide speed and torque four-quadrant simulation results are provided, which validate the proposed sensorless strategy for being further implemented in EV.Peer ReviewedPostprint (author's final draft

Génératrice à réluctance variable connectée au réseau alternatif monophasé pour une application éolienne

Nous avons présenté dans ce travail le contrôle de la Génératrice à Réluctance Variable (GRV) connectée au réseau alternatif monophasé pour une application éolienne. La régulation de la vitesse de rotation est assurée par le convertisseur coté génératrice et le couple est imposé par la machine à courant continu utilisée ici pour simuler la turbine éolienne. La connexion de la génératrice au réseau est réalisée par un convertisseur DC-AC qui assure le maintien de la tension du bus DC par un correcteur PI. Un correcteur résonant est utilisé pour suivre la consigne de courant sinusoïdale.Peer ReviewedPostprint (published version

IPMSM torque control strategies based on LUTs and VCT feedback for robust control under machine parameter variations

In recent years, Interior Permanent Magnet Synchronous Machines (IPMSMs) have attracted a considerable attention in the scientific community and industry for Electric and Hybrid Electric Vehicle (HEV) propulsion systems. Lookup Table (LUT) based Field Oriented Control (FOC) strategies are widely used for IPMSM torque control. However, LUTs strongly depend on machine parameters. Deviations of these parameters due to machine ageing, temperature or manufacturing inaccuracies can lead to control instabilities in the field weakening region. In this paper, two novel hybrid IPMSM control strategies combining the usage of LUTs and Voltage Constraint Tracking (VCT) feedbacks are proposed in order to overcome the aforementioned controllability issues. Simulation results that demonstrate the validity of the proposed approaches are presented.Postprint (author's final draft

Moving towards the maximum speed in stepping motors by means of enlarging the bandwidth of the current controller

This paper pursues to maximise the mechanical speed when using stepping motors (SM) without position sensors in order to achieve a rapid-response manufacturing whenever any equipment based on such electrical machines is involved. The novelty of this paper is the fact that not only the bandwidth of the current controllers is improved for such maximization of the SM mechanical speed, as traditionally done in previous works, but also a comprehensive approach has been addressed. Such global approach starts justifying why the traditional PI controller is not sufficient and it includes the analytical tuning of the current controllers, considering implementation tiny issues (but of paramount importance) such as the delays caused by the processor and the sample and hold current measurements. It is proved and justified that this previously mentioned issues, which are often omitted, play a crucial role when trying to maximise the speed of the SM, since the electrical fundamental frequencies of the SM move close to the sampling frequency. Therefore, the analytical process to tune and implement the current controllers will have to be done in discrete-time domain, i.e. using the Z transform and treating the SM drive as a sampled data system. Experimental waveforms and results based on real prototypes will prove the validity of the entire research. Finally, a real case-study based on Printed Circuit Board (PCB) prototyping machine which is composed by two stepper machines, is fully reported. Such PCB prototype is the fruitful collaboration between the University (research institution) and a private company (industry). © 2016 Elsevier LtdPeer ReviewedPostprint (author's final draft

Fixed Switching Period Discrete-Time Sliding Mode Current Control of a PMSM

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksA fixed switching period sliding mode control (SMC) for Permanent Magnet Synchronous Machines (PMSMs) is presented. The aim of the paper is to design a SMC that improves the traditional PI based Field Oriented Control (FOC) transient response, as well as to reduce the switching frequency variations of the Direct Torque Control (DTC). Such SMC requires a decoupling method of the control actions, which also brings constant switching functions slopes. These constant slopes allow to calculate the required hysteresis band value to control the switching frequency. The digital implementation degrades the performance of the hysteresis comparator and as a consequence, the previously calculated band becomes inaccurate to regulate the switching frequency. In order to recover the analogue hysteresis band comparator performance, a predictive algorithm is proposed. Finally, a set of experimental results with constant switching frequency during a torque reversal and speed control tests are provided.Peer ReviewedPostprint (author's final draft

Control óptimo de par para máquinas SynRM aplicadas a vehículo eléctrico

Las máquinas de reluctancia síncrona asistidas por imanes están atrayendo un considerable interés como alternativa a las máquinas síncronas de imanes permanentes para su uso en sistemas de propulsión de vehículos eléctricos. El control óptimo de estas máquinas (incluyendo operación en debilitamiento de campo) puede resultar complejo, ya que estas son, por lo general, muy sensibles al fenómeno de la saturación magnética. En este artículo se trata su control, desde los reguladores hasta el precalculo de referencias de corriente óptimas para todo el rango de operación de la máquina. Finalmente, se muestran resultados experimentales obtenidos en una máquina de 51 kW.Postprint (published version

Ibilgailu elektrikoen propultsio-sistemak: motor elektrikoak eta horien kontrola

This article provides a state of the art of the electric machine technology used in Electric and Hybrid Electric Vehicle applications. Most common FOC (Field Oriented Control) and the DTC (Direct Torque Control) strategies are explained and compared. Position and speed sensorless control strategies are also detailed: observer-based estimators, suitable for medium/high speed ranges and magnetic saliency based methods, applicable for low speeds and standstill operation. Finally, challenges and future trends of this technology are provided.Postprint (published version

Reducing the cogging torque effects in hybrid stepper machines by means of resonant controllers

Permanent magnet machines are not free from the interaction between magnets and the stator and rotor slots, which causes an undesired disturbing torque. Such cogging or detent torque is especially larger with salient pole machines, as it is the case of the Permanent Magnet Hybrid Stepper Machines (PMHSM). Depending on the application requirements, these torque perturbations can be unacceptable and the application of solutions that minimizes the cogging torque effects are mandatory. This paper originally faces the minimization of the cogging torque using resonant controllers. More specifically, the paper details the analysis and design of a speed-adaptive resonant controller, which not only is directly designed in Z domain but also considers the current (or torque) inner loop delay. Pole-zero placement and the disturbance rejection frequency response have been attained in the design of the speed and position speedadaptive controllers. Experimental results with two off-theshelf PMHSMs demonstrate the superior performance of the proposal in both speed and position closed-loop applications for tracking, as well as in disturbance (load impact) rejection tests and against inertia variations. A comparison with a conventional PI has been carried out from the design stage to experimental results and the improvement of the proposal has been numerically quantified.Postprint (published version

Common mode output waveform reduction for matrix converter drives

This paper presents an alternative Space Vector Modulation (SVM) implemented in Matrix Converters (MC) which improves and reduces the Common Mode (CM) voltage and current output waveforms. The strategy is based on replacing the MC zero vectors for the rotating ones, which reduces the CM voltage derivative and therefore the leakage CM current. By reducing this CM current, which might flow inside the motor through the bearings and windings, the Permanent Magnet Synchronous Machine (PMSM) deterioration might be slowed down. The paper describes the novel SVM pattern and analyses the CM voltage and its leakage current. Simulation results based on PMSM drive are provided to corroborate the whole idea.Peer ReviewedPostprint (published version