A Dual-Voltage-Vector Model-Free Predictive Current Controller for Synchronous Reluctance Motor Drive Systems

Abstract

For current control in power conversion and motor drive systems, there exist three classic methods in the literature and they are the hysteresis current control (HCC), the sine pulse-width modulation (SPWM), and the space vector pulse width modulation (SVPWM). HCC is easy to implement, but has relatively large current harmonic distortion as the disadvantage. On the other hand, the SPWM and SVPWM use modulation technique, commonly together with at least one proportional-integral (PI) regulator to reduce load current ripples, and hence demanding more computation time. This paper aims to improve the performance of a recently proposed new current control method-the single-voltage-vector model predictive current control (SVV-MPCC), for synchronous reluctance motor (SynRMs) drives. To that end, a dual-voltage-vector model-free predictive current control (DVV-MFPCC) for SynRMs is proposed. Unlike the SVV-MPCC that applies only a single voltage vector per sampling period, the proposed DVV-MFPCC is capable of providing two successive segmentary current predictions in the next sampling period through all possible combinations from any two candidate switching states increasing the number of applicable switching modes from seven to nineteen and reducing the prediction error effectively. Moreover, the new control does not utilize any parameters of the SynRM nor its mathematical model. The performance is effectively enhanced compared to that of SVV-MPCC. The working principle of the DVV-MFPCC will be detailed in this paper. Finally, the SVV-MPCC, the single-voltage-vector model-free predictive current control (SVV-MFPCC), the dual-voltage-vector model predictive current control (DVV-MPCC), and the DVV-MFPCC are realized to control the stator currents of SynRM through a 32-bit microcontroller TMS320F28377S. Experimental results are provided to validate the new method and verify that the DVV-MFPCC performs better than do the SVV-MPCC, the SVV-MFPCC, and the DVV-MPCC.

Predictive Controllers for Dual-Voltage Vector Current-Slope Sensorless IPMSM Drives

“…A dual-voltage vector MPCC is developed by using a minimization method which uses six cost functions and synthesizes six active-voltage vectors and two zero-voltage vectors, which are fewer than previous research has used in order to determine the first voltage vector [3]- [6]. The second voltage vector is determined by using a predictive voltage reference command.…”

“…Several researchers have investigated dual-voltage vector modulation for an IPMSM attached to an encoder. For example, Lin et al used a synthesis of dual-voltage vectors with 19 switching states based on a cost function, which effectively reduced the current harmonics and torque ripples [3]. Chen et al proposed a simplified dual-vector method which uses a projection of the current error of the active vector to minimize cost function [4].…”

A Modulated Model Predictive Current Controller for Interior Permanent-Magnet Synchronous Motors

“…Current changes from the applied voltage vectors are utilized to predict future currents. A similar technique is adopted in [22], where two active voltage vectors with equal durations were applied in a sampling period. However, its efficiency is uncertain to some extent, due to the large number of candidate voltage vectors to be optimized.…”

Low cogging torque design and simplified model-free predictive current control for radial-flux dual three-phase permanent magnet electric machines

“…21 A dual-voltage-vector model-free predictive current control (DVV-MFPCC) for synchronous reluctance motors had been proposed to compare with single-voltage vector (SVV) and the MPCC, respectively, and then DVV-MFPCC had better current-tracking performance than SVV-MPCC, SVV-MFPCC and DVV-MPCC. 22 Therefore, this article presents a simplified model-free predictive current control (SMFPCC) method for the designed radial-flux dual three-phase PMEMs. The SMFPCC is different from MPCC.…”