Soutenance mémoire
Modeling of the encoder position error due to different nonidealities
The rotor position error produced by the main nonidealities contained in the quadrature signals from analog encoders and resolvers has been investigated previously in (Hanselman, 1990; 1991; Hwang et al., 2011; Lara and Chandra, 2014b; Lin et al., 2011; Nasiri-Gheidari and Tootoonchian, 2015; Ramakrishnan et al., 2013). The contribution of this study to the literature on this subject is an extended and more accurate modeling of the position error. The set of equations presented in this paper has been derived considering the general case when the nonidealities are contained in both quadrature signals as well as when the amplitude of the harmonics in the sine and cosine waveforms is different. The following theoretical analysis of the encoder position error is based on the type-2 PLL of Figure 2.1. Both the linear and nonlinear PLL structures are used for deriving the equations that model the position error. For analysis and design purposes, the simplifying locked condition of the linearized PLL scheme is considered (Harnefors and Nee, 2000). Rotor position error as a function of the PMSM speed The rotor position error obtained after applying the PA algorithm has been measured in the whole operating speed range of the PMSM following the trapezoidal motion profile presented in Figure 2.12 c). The maximum speed and constant acceleration rates have been set to 5000 r/min and 1000 r/min/s2, respectively. In Figure 2.12 d), it can be observed how the PA algorithm reduces the rotor position error from 4.3 to 1.6 electrical degrees and how it remains inside this range along the entire speed for both rotation directions, thus demonstrating the validity of the proposed static compensation under different dynamic conditions.
The use of a PLL processing the sine–cosine encoder signals previously compensated with the PA algorithm not only helps to reduce the remaining position error in the high speed range of the PMSM but will contribute to reject the high-frequency spikes induced in the encoder signals during commutation of the inverter. The high-rate input variations are fairly attenuated by the inherent low-pass filter (LPF) response of the PLL structure (Emura and Lei, 2000). Figure 2.12 e) shows the performance improvement of the PA algorithm through a type-2 PLL with speed feedforward compensation. It can be noted how the high-frequency components from the encoder signals are attenuated by the loop filter of the PLL allowing to reduce the total position error to less than 1. The analysis and design of the PLL are presented in the Appendix I. In order to evaluate the performance of the proposed PA compensation algorithm, two different tests were performed. The first test only considers the rotor position error from the encoder itself and that is produced by the nonidealities contained in the quadrature analog signals, whereas the second test evaluates the total position error including the EMI generated during the commutation of the inverter with a dc bus rated at 400 V and the flowing of stator currents of up to 300 Apk. In the tests, the induction machine is controlled in speed mode and the 80 kW PMSM in torque mode. The obtained results for both motoring and regenerative braking operation modes are shown in Figure 2.15. The normalized ramp rotor position the position error before (B) and after (A) the PA compensation as well as the position error obtained when using the PLL can be observed. At both speeds of 6000 and 9000 r/min and under no commutation conditions, the uncompensated position error varies between 0.8 mechanical degrees, whereas after applying the proposed PA algorithm, this error is reduced to 0.2. When the machine develops the maximum torque of 85 Nm at 6000 r/min and 55 Nm at 9000 r/min, the effects of the inverter commutation are readily observed. However, given that the nonidealities were previously well compensated with the PA algorithm, the highfrequency spikes are quite reduced by the loop filter of the PLL, thus allowing to achieve a total position error confined to a range as small as 0.75 electrical degrees.
Problème liée à la géométrie du joint brasé
Parmi les problèmes rencontrés en fabrication des joints et plus particulièrement les joints en T, le défaut de perpendicularité qui empêche la formation de la microstructure lamellaire sur l’intégralité de la jonction entre les deux plaques brasés comme le montre la Figure 1-20 (Chabrol, 2014). Figure 1-20 Défaut de perpendicularité dans un joint en T brasé à 900°C (Chabrol, 2014). Les solutions proposées dans la littérature pour un maintien en parfaite perpendicularité, sont les taquages et les gabarits de maintien. Le gabarit de maintien doit être fabriqué d’un matériau non-réactif avec le titane, l’acier carbone et le graphite revêtu d’alumine AlO (le revêtement est utilisé pour éviter une carburation des pièces) présentent une bonne solution, contrairement au nickel, en contact avec le titane forme des eutectiques à basse température de fusion, qui provoquera une fusion du gabarit avec les pièces à braser (Campbell, 2012b). Il doit permettre une dilatation et une contraction afin de ne pas provoquer des distorsions de l’assemblage. Des ressorts peuvent être ajoutés pour maintenir les composants; les matériaux de ressorts les plus recommandées sont l’acier et l’inconel et la zone de contact doit être réduite à une ligne de contact pour minimiser le transfert de chaleur entre les composants et le gabarit. Par ailleurs, d’autres matériaux qui forment des eutectiques peuvent être utilisés à condition qu’ils soient séparés du titane par un placage par pulvérisation ou à la brosse. Les types de placages utilisés sont l’oxyde d’aluminium stable ou l’oxyde de zirconium (Fabian, 1993). La fabrication d’un gabarit de maintien est prévue dans le cadre de ce projet, comme solution au problème de discontinuité de la microstructure lamellaire le long du joint brasé en T.
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Table des matières
INTRODUCTION
CHAPTER 1 RESEARCH OUTLINE
1.1 Problem statement
1.2 Literature review
1.3 Objectives and methodology
1.4 Originality and contribution
1.5 Publications
1.6 Thesis summary
CHAPTER 2 A NOVEL ALGORITHM BASED ON POLYNOMIAL APPROXIMATIONS FOR AN EFFICIENT ERROR COMPENSATION OF MAGNETIC ANALOG ENCODERS IN PMSMS FOR EVS
2.1 Introduction
2.2 Modeling of the encoder position error due to different nonidealities
2.2.1 Amplitude mismatch
2.2.2 Nonzero dc offset
2.2.3 Nonorthogonality
2.2.4 Harmonic distortion
2.3 Calibration procedure in PMSMs and PA compensation algorithm
2.3.1 Calibration procedure in PMSMs
2.3.2 PA compensation algorithm
2.4 Experimental results
2.4.1 Calibration and PA compensation
2.4.2 Rotor position error as a function of the PMSM speed
2.5 Validation with 80 kW PMSM
2.6 Conclusion
2.7 Acknowledgment
CHAPTER 3 EFFECTS OF ROTOR POSITION ERROR IN THE PERFORMANCE OF FIELD-ORIENTED-CONTROLLED PMSM DRIVES FOR ELECTRIC VEHICLE TRACTION APPLICATIONS
3.1 Introduction
3.2 Modeling of the torque ripple produced in PMSMs due to the error from the rotor position sensor
3.3 Characteristic trajectories in the different operating regions of the PMSM
3.4 Torque ripple evaluation along the characteristic trajectories of the PMSM
3.5 Rotor position sensor and rotor position error compensation algorithm
3.5.1 Rotor position sensor
3.5.2 Rotor position error compensation algorithm
3.6 Experimental results
3.6.1 Frequency-domain analysis of the torque ripple and the rotor position error
3.7 Experimental validation with an 80-kW SMPMSM
3.8 Conclusion
CHAPTER 4 PERFORMANCE INVESTIGATION OF TWO NOVEL HSFVI DEMODULATION ALGORITHMS FOR ENCODERLESS FOC OF PMSMS INTENDED FOR EV PROPULSION: A DSP-BASED EXPERIMENTAL STUDY
4.1 Introduction
4.2 Model of SVM-based high frequency signal injection for encoderless FOC of PMSM
4.2.1 Pulsating Voltage Signal Injection: – HFSVM
4.2.2 Rotating Voltage Signal Injection: – HFSVM
4.3 Model of PWM-based half switching frequency signal injection for encoderless FOC of PMSM
4.3.1 Rotating Voltage Signal Injection: – HSFPWM
4.3.2 Pulsating Voltage Signal Injection: – HSFPWM
4.4 Analysis and performance comparison of the four HFSI techniques
4.5 Conclusion
GENERAL CONCLUSION
FUTURE WORK
APPENDIX I ANALYSIS AND DESIGN OF THE PLL USED IN EXPERIMENTS
APPENDIX II BASE, CRITICAL, AND MAXIMUM SPEED IN PMSMS
APPENDIX III QUALITATIVE AND QUANTITATIVE PERFORMANCE COMPARISON OF THE FOUR HFSI TECHNIQUES
APPENDIX IV DETAILED PROCEDURE FOR THE DERIVATION OF SOME IMPORTANT EQUATIONS INCLUDED IN THE TRANSACTIONS PAPERS
BIBLIOGRAPHY
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