Sensorless finite-control set model predictive control for IPMSM drives

This paper investigates the feasibility of a sensorless field oriented control (FOC) combined with a finite control set model predictive current control (FCS-MPC) for an interior permanent magnet synchronous motor (IPMSM). The use of a FCS-MPC makes the implementation of most of the existing sensorless techniques difficult due to the lack of a modulator. The proposed sensorless algorithm exploits the saliency of the motor and the intrinsic higher current ripple of the FCS-MPC to extract position and speed information using a model-based approach. This method does not require the injection of additional voltage vectors or the periodic interruption of the control algorithm and consequently it has no impact on the performance of the current control. The proposed algorithm has been tested in simulation and validated on an experimental set-up, showing promising results

Injectionless Sensorless Control of Synchronous Reluctance Machine for Zero to Low Speeds Region

An alternative to the high frequency injection approach for sensorless control at zero and low speed region is proposed for synchronous reluctance machines (SyR) using finite-control-set model predictive control (FCS-MPC). The saliency based position estimate aims to exploit the switching current ripple which is pronounced owing to the nature of MPC especially around zero and low speed region due to the minimal back-emf. A demerit of the high frequency injection techniques is the bandwidth hindrance of position observer by the demodulating low pass filter (LPF). In the proposed method, no such filters are required and consequently, high bandwidth is achieved. Guidelines for the calibration of observers are addressed. In addition, the effects of cross-saturation on position estimation is inherently considered. The experimental validation on a 1 kW SyR shows stable operation under torque and speed transients, and proves the feasibility of the proposed technique

IGBT-SiC dual fed open end winding PMSM drive

This paper proposes a dual fed common dc link inverter Open End Winding-Permanent Magnet Synchronous Motor (OEW-PMSM) Drive. In order to increase the system efficiency a dual technology converter is used, with one inverter composed of standard IGBT devices and the other composed of fast switching Silicon Carbide (SiC) devices. The common dc link OEW configuration allows the zero-sequence current (ZSC) to flow freely, and the low time constants of the zero-circuit can lead to high zero sequence current flow, with associated losses and stress on the power devices. To avoid this, the zero-sequence voltage produced by the switching combinations adopted to synthetize the control signals needs to be instantaneously eliminated. A novel modulation for dual converter configurations is proposed to eliminate the zero-sequence voltage(ZSV)

Model Predictive Control for shunt active filters with fixed switching frequency

This paper presents a modification to the classical Model Predictive Control algorithm, named Modulated Model Predictive Control, and its application to active power filters. The proposed control is able to retain all the advantages of a Finite Control Set Model Predictive Control whilst improving the generated waveforms harmonic spectrum. In fact a modulation algorithm, based on the cost function ratio for different output vectors, is inherently included in the MPC. The cost function-based modulator is introduced and its effectiveness on reducing the current ripple is demonstrated. The presented solution provides an effective and straightforward single loop controller, maintaining an excellent dynamic performance despite the modulated output and it is self-synchronizing with the grid. This promising method is applied to the control of a Shunt Active Filter for harmonic content reduction through a reactive power compensation methodology. Significant results obtained by experimental testing are reported and commented, showing that MPC is a viable control solution for active filtering systems

Modulated model predictive current control of an indirect matrix converter with active damping

A modulated model predictive control (M²PC) scheme for an indirect matrix converter is proposed in this paper, including an active damping method to mitigate the input filter resonance. The control strategy allows the instantaneous power control and the output current control at the same time, operating at a fixed frequency. An optimal switching pattern is used to emulate the desired waveform quality features of space vector modulation and achieve zero-current switching operations. The active damping technique emulates a virtual resistor which damps the filter resonance. Simulation results present a good tracking to the output-current references, unity input displacement power factor, the low input-current distortions and a reduced common-mode voltage (CMV)

Modulated predictive control for indirect matrix converter

Finite State Model Predictive Control (MPC) has been recently applied to several converter topologies as it can provide many advantages over other MPC techniques. The advantages of MPC include fast dynamics, multi-target control capability and relatively easy implementation on digital control platforms. However, its inherent variable switching frequency and lower steady state waveform quality, with respect to standard control which includes an appropriate modulation technique, represent a limitation to its applicability. Modulated Model Predictive Control (M2PC) combines all the advantages of MPC with the fixed switching frequency characteristic of PWM algorithms. The work presented in this paper focuses on the Indirect Matrix Converter (IMC), where the tight coupling between rectifier stage and inverter stage has to be taken into account in the M2PC design. This paper proposes an M2PC solution, suitable for IMC, with a switching pattern which emulates the desired waveform quality features of Space Vector Modulation (SVM) for matrix converters. The switching sequences of the rectifier stage and inverter stage are rearranged in order to always achieve zero-current switching on the rectifier stage, thus simplifying the current commutation strategy

FPGA Implementation of a Novel Oversampling Deadbeat Controller for PMSM Drives

This paper presents a novel oversampling deadbeat current control approach for permanent magnet synchronous motor drives capable of operating at a controller sampling frequency multiple of the power converter switching frequency. Model-based controllers suffer from heavy computational demand and performance degradation due to parameter uncertainties. The proposed controller concurrently with field-programmable gate array implementation permits to achieve a constant switching frequency and an optimal current ripple along with a high current-loop bandwidth and robust behavior to parameter variation. A disturbance observer has been added to the proposed controller in order to compensate for the converter voltage distortions. The proposed control strategy is tested through both simulations and experiments

Analysis and Design Optimization of a Permanent Magnet Synchronous Motor for a Campus Patrol Electric Vehicle

© 1967-2012 IEEE. This work presents the analysis, design and optimization of a permanent magnet synchronous motor (PMSM) for an electric vehicle (EV) used for campus patrol with a specific drive cycle. Firstly, based on the collected data like the parameters and speed from a test EV on the campus road, the dynamic calculation of the EV is conducted to decide the rated power and speed range of the drive PMSM. Secondly, according to these requirements, an initial design and some basic design parameters are obtained. Thirdly, optimization process is implemented to improve the performance of the designed PMSM. The permanent magnet (PM) structure, airgap length and stator core geometry are optimized respectively in this step. Different optimization processes are proposed to meet multiple optimization objectives simultaneously. Based on the finite element analysis (FEA) method, it is found that the harmonic of the optimized PMSM is lower than that of the initial design, and the torque ripple is reduced by 24%. The effectiveness of optimization on the core loss and PM eddy loss is validated and the temperature rise is suppressed effectively. Finally, a prototype is fabricated for the optimized PMSM and an experimental platform is developed. The test results verify that the optimized PMSM meets the requirements of the specific campus patrol EV well

A New Position and Speed Estimation Scheme for Position Control of PMSM Drives Using Low-Resolution Position Sensors

A new position control method for permanent magnet synchronous motor (PMSM) drive with a low-resolution encoder is proposed in this paper. Three binary Hall position sensors are utilized to realize a moderate-performance position control system for the consideration of economy and simplicity in servo application. Compared with sensorless control, the usage of binary Hall position sensors is a guarantee of both control performance and low cost. However, the low resolution of the Hall sensor will heavily deteriorate the accuracy of the position and speed calculation. Such drawback can be effectively minimized by using appropriate position and speed estimation schemes. With the help of polynomial fitting and state observer techniques, a solution is provided to realize semi-closed loop control by treating the position and speed estimators as separate systems. The performance can be improved (1) by proposing a polynomial fitting scheme with least squares method, high-resolution rotor-position predictor can be derived by fitting the predefined position data from binary Hall position sensors in a linear or quadratic manner; (2) by adopting the dual-sampling-rate observer, instantaneous speed can be estimated at each control cycle and the estimation error is corrected once a new measurement form the Hall arrives. Furthermore, a nonlinear position control algorithm is introduced to increase standstill stability. Extensive experimental results are given to demonstrate the feasibility of the proposed method and its superiority over conventional methods

A Nonlinear Extended State Observer for Rotor Position and Speed Estimation for Sensorless IPMSM Drives

© 1986-2012 IEEE. Sensorless machine drives in vehicle traction frequently experience rapidly-changing load disturbance and demand fast speed dynamics. Without gain-scheduling or compensation, conventional quadrature phase-locked-loop (Q-PLL) is unable to accurately estimate the rotor position and speed for these systems. In this paper, a third-order nonlinear extended state observer (TNESO) is proposed for position and speed estimation for sensorless interior permanent magnet synchronous motor drives. TNESO has the power of nonlinear feedback and takes the advantages of fast convergence and disturbance rejection. An optimized parameter configuration method is deployed to extend the disturbance observation bandwidth of the TNESO. Both steady state and transient performance of TNESO are verified through the experimental tests. In comparison with the performance of conventional Q-PLL scheme, the proposed observer is proved to be capable of delivering higher precision of position and speed estimation against rapidly varying disturbance in wide operating range