scholarly journals Performance Improvement for PMSM DTC System through Composite Active Vectors Modulation

Electronics ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 263 ◽  
Author(s):  
Tianqing Yuan ◽  
Dazhi Wang

In this paper, a novel direct torque control (DTC) scheme based on composite active vectors modulation (CVM) is proposed for permanent magnet synchronous motor (PMSM). The precondition of the accurate compensations of torque error and flux linkage error is that the errors can be compensated fully during the entire control period. Therefore, the compensational effects of torque error and flux linkage error in different operating conditions of the PMSM are analyzed firstly, and then, the operating conditions of the PMSM are divided into three cases according to the error compensational effects. To bring the novel composite active vectors modulation strategy smoothly, the effect factors are used to represent the error compensational effects provided by the applied active vectors. The error compensational effects supplied by single active vector or synthetic voltage vector are analyzed while the PMSM is operated in three different operating conditions. The effectiveness of the proposed CVM-DTC is verified through the experimental results on a 100-W PMSM drive system.

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2154 ◽  
Author(s):  
Dazhi Wang ◽  
Tianqing Yuan ◽  
Xingyu Wang ◽  
Xinghua Wang ◽  
Yongliang Ni

In order to improve the performance of the servo control system driven by a permanent magnet synchronous motor (PMSM) under novel direct torque control (NDTC), which, utilizing composite active vectors, fixed sector division criterion, is proposed in this paper. The precondition of the accurate compensations of torque and flux errors is that the sector where the stator flux linkage is located can be determined accurately. Consequently, the adaptive sector division criterion is adopted in NDTC. However, the computation burden is inevitably increased with the using of the adaptive part. On the other hand, the main errors can be compensated through SV-DTC (DTC-utilizing single active vector), while another active vector applied in NDTC can only supply the auxiliary error compensation. The relationships of the two active vectors’ characteristics in NDTC are analyzed in this paper based on the active factor. Furthermore, the fixed sector division criterion is proposed for NDTC (FS-NDTC), which can classify the complexity of the control system. Additionally, the switching table for the selections of the two active vectors is designed. The effectiveness of the proposed FS-NDTC is verified through the experimental results on a 100-W PMSM drive system.


Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2729 ◽  
Author(s):  
Dazhi Wang ◽  
Tianqing Yuan ◽  
Xingyu Wang ◽  
Xinghua Wang ◽  
Wenhui Li

The operation performance of permanent magnet synchronous motors (PMSMs) driven by direct torque control (DTC) are affected by torque error compensation and flux error compensation in each control period. The error compensational effects provided by different vectors under different control strategies are analyzed in this paper. The precondition of accurate error compensation is applied to the proposed novel composite vectors modulation strategy (CVM) for a PMSM DTC system. In CVM-DTC, the operating conditions of PMSM are divided into three cases according to the relationships between the errors and the actual error compensations, including steady-state case, dynamic-state case, and transient-state case. In order to establish the novel CVM-DTC strategy smoothly, the effect factors are introduced and used to represent the error compensational effects, which are obtained through the proposed effect factors’ controller. The analysis of error compensational effects provided by single active vector and synthetic voltage vector are described in detail while the PMSM is operated in different operation conditions. Finally, the effectiveness of the novel CVM-DTC strategy is verified through the experimental results in a 100-W PMSM drive system.


2012 ◽  
Vol 220-223 ◽  
pp. 631-634
Author(s):  
Xian Xing Liu ◽  
Na Fu

A new scheme of deadbeat direct torque control (DTC) of surface permanent magnet synchronous motor (SPM) is proposed in this paper. The main ideal is choosing the reference voltage vector in two phase stator reference frame previously and real-time calculating the pulse width of the reference voltage vector which diminish the error of torque. With the new scheme, the torque ripples were greatly reduced when compared with those of the basic DTC and the quick dynamic torque response of the basic DTC was still retained. Fixed switching frequency at different operating conditions becomes possible by this new structure. Simulation results verify the correctness and feasibility of this method.


2018 ◽  
Vol 41 (2) ◽  
pp. 504-515 ◽  
Author(s):  
Chen Feng ◽  
Xia Chaoying ◽  
Hou Xiaoxin

In direct torque controlled permanent magnet synchronous motor drives, when the rotor speed or the load torque changes, the effect of a certain voltage vector on the torque also changes. In heavy-load or high-speed operating conditions, the torque may lose control. This paper presents an intensive investigation into this issue. With the help of relevant derivative curves, the primary cause for the losing control problem is analysed. Further study reveals that the effect of a certain voltage vector on the load angle is no relevant for the load conditions. Based on this property, by replacing the torque hysteresis comparator with a load angle hysteresis comparator, a modified direct torque control called the load-angle-feedback direct torque control is proposed and the original superiorities of the direct torque control are well preserved. Comparison between the direct torque control and the proposed method shows that the load capacity and speed operation range may be obviously extended by utilizing the proposed method.


2020 ◽  
Vol 306 ◽  
pp. 04007
Author(s):  
Qianni Li ◽  
Aide Xu ◽  
Chaoyi Shang ◽  
Lepeng Huang

This paper proposes a novel deadbeat torque and flux control (DB-DTFC) to reduce torque ripple for switched reluctance motor (SRM). DB-DTFC combines the advantages of direct torque control (DTC) and space-vector modulation (SVM). DB-DTFC leads current vector control into DTC in order to find the equation between torque and current through deadbeat prediction theory i.e. a beat reaches a given point. In addition, the deadbeat calculation module here is similar to that of permanent magnet synchronous motor. Based on dq0 reference frame of SRM, the most suitable dq0 axis current of next moment corresponding to different torque errors is calculated and predicted. According to the calculated dq0 axis current, the optimal space voltage vectors can be selected to reduce torque ripple. In order to verify the effectiveness and correctness of the proposed scheme, DB-DTFC is verified and compared with the DTC-SVM by simulation.


2012 ◽  
Vol 614-615 ◽  
pp. 1570-1573
Author(s):  
Ying Pei Liu ◽  
Ran Li ◽  
Zhi Chao Zhang

In order to reduce the ripples of flux linkage and torque for direct torque control (DTC) and ensure constant inverter switching frequency, permanent magnet synchronous motor (PMSM) DTC based on space vector modulation (SVM) and extended Kalman filter (EKF) is researched in the paper. Simulation results have shown that the inherent advantages of fast dynamic response of DTC are maintained, and flux linkage and torque ripples are effectively reduced. Speed is estimated accurately, and sensorless operation is realized.


Author(s):  
Hanaa Elsherbiny ◽  
Mohamed Kamal Ahmed ◽  
Mahmoud Elwany

This paper presents a detailed analysis and comparative investigation for the torque control techniques of interior permanent magnet synchronous motor (IPMSM) for electric vehicles (EVs). The study involves the field-oriented control (FOC), direct torque control (DTC), and model predictive direct torque control (MPDTC) techniques. The control aims to achieve vehicle requirements that involve maximum torque per ampere (MTPA), minimum torque ripples, maximum efficiency, fast dynamics, and wide speed range. The MTPA is achieved by the direct calculation of reference flux-linkage as a function of commanded torque. The calculation of reference flux-linkage is done online by the solution of a quartic equation. Therefore, it is a more practical solution compared to look-up table methods that depend on machine parameters and require extensive offline calculations in advance. For realistic results, the IPMSM model is built considering iron losses. Besides, the IGBTs and diodes losses (conduction and switching losses) in power inverter are modeled and calculated to estimate properly total system efficiency. In addition, a bidirectional dc-dc boost converter is connected to the battery to improve the overall drive performance and achieve higher efficiency values. Also, instead of the conventional PI controller which suffers from parameter variation, the control scheme includes an adaptive fuzzy logic controller (FLC) to provide better speed tracking performance. It also provides a better robustness against disturbance and uncertainties. Finally, a series of simulation results with detailed analysis are executed for a 60 kW IPMSM. The electric vehicle (EV) parameters are equivalent to Nissan Leaf 2018 electric car.


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