scholarly journals A Composite Vectors Modulation Strategy for PMSM DTC Systems

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.

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.


Author(s):  
Mohamed Chebaani ◽  
Amar Goléa ◽  
Med Toufik Benchouia ◽  
Noureddine Goléa

Purpose Direct Torque Control (DTC) of induction motor drives is a well-established technique owing to features such as fast dynamic and insensibility to motor parameters. However, conventional DTC scheme, based on comparators and the switching table, suffers from large torque and flux ripples. To improve DTC performance, this study aims to propose and implement a sensorless finite-state predictive torque control using extended Kalman Filter in dSPACE environment. Design/methodology/approach This paper deals with the design of an extended Kalman filter for estimating the state of an induction motor model and for sensorless control of systems using this type of motor as an actuator. A complex-valued model is adopted that simultaneously allows a simpler observability analysis of the system and a more effective state estimation. Findings Simulation and experimental results reveal that the drive system, associated with this technique, can effectively reduce flux and torque ripples with better dynamic and steady state performance. Further, the proposed approach maintains a constant switching frequency. Originality/value The proposed speed observer have been developed and implemented experimentally under different operating conditions such as parameter variation, no-load/load disturbances and speed variations in different speed operation regions.


Author(s):  
Jagdish Gangadharrao Chaudhari ◽  
Sanjay Bhauraoji Bodkhe ◽  
Mohan V. Aware

In this paper, an improved proportional integral stator resistance estimation for a direct torque controlled induction motor is proposed. This estimation method is based on an on-line stator resistance correction regarding the variations of the stator current estimation error. In fact, the input variable of the PI estimator is the stator current estimation error. The main idea is to tune accurately the stator resistance value relatively to the evolution of the stator current estimation error gradient to avoid the drive instability and ensure the tracking of the actual value of the stator resistance. But there is an unavoidable steady state error between the filtered stator current modulus and its estimated value from the dq model of the machine which is due to pseudo random commutations of the inverter switches. An offset has been introduced in order to overcome this problem, for different speed command values and load torques. Simulation results show that the proposed estimator was able to successfully track the actual value of the stator resistance for different operating conditions


2014 ◽  
Vol 573 ◽  
pp. 155-160
Author(s):  
A. Pandian ◽  
R. Dhanasekaran

This paper presents improved Fuzzy Logic Controller (FLC) of the Direct Torque Control (DTC) of Three-Phase Induction Motor (IM) for high performance and torque control industrial drive applications. The performance of the IM using PI Controllers and general fuzzy controllers are meager level under load disturbances and transient conditions. The FLC is extended to have a less computational burden which makes it suitable for real time implementation particularly at constant speed and torque disturbance operating conditions. Hybrid control has advantage of integrating a superiority of two or more control techniques for better control performances. A fuzzy controller offers better speed responses for startup and large speed errors. If the nature of the load torque is varied, the steady state speed error of DTC based IM drive with fuzzy logic controller becomes significant. To improve the performance of the system, a new control method, Hybrid fuzzy PI control is proposed. The effectiveness of proposed method is verified by simulation based on MATLAB. The proposed Hybrid fuzzy controller has adaptive control over load toque variation and can maintain constant speed.


2011 ◽  
Vol 7 (1) ◽  
pp. 42-49
Author(s):  
Turki Abdalla ◽  
Haroution Hairik ◽  
Adel Dakhil

Among all control methods for induction motor drives, Direct Torque Control (DTC) seems to be particularly interesting being independent of machine rotor parameters and requiring no speed or position sensors. The DTC scheme is characterized by the absence of PI regulators, coordinate transformations, current regulators and PWM signals generators. In spite of its simplicity, DTC allows a good torque control in steady state and transient operating conditions to be obtained. However, the presence of hysterics controllers for flux and torque could determine torque and current ripple and variable switching frequency operation for the voltage source inverter. This paper is aimed to analyze DTC principles, and the problems related to its implementation, especially the torque ripple and the possible improvements to reduce this torque ripple by using a proposed fuzzy based duty cycle controller. The effectiveness of the duty ratio method was verified by simulation using Matlab/Simulink software package. The results are compared with that of the traditional DTC models.


2012 ◽  
Vol 1 (3) ◽  
pp. 54-83 ◽  
Author(s):  
Mohamed M. Ismail

Direct torque control (DTC) of an induction motor fed by a voltage source inverter is a simple scheme that doesn’t need long computation time. The motor terminal voltages and currents are sampled to estimate the motor flux linkage and electromagnetic torque using a flux observer. The main advantage of DTC technique is that it isn’t sensitive to the variation in motor parameters except the stator resistance in its flux observer especially at low speed operation. In this paper, two observers are used for online stator resistance identification for the DTC flux observer, one observer based on fuzzy logic while the other is based on ANFIS algorithm. The saturated p model of the induction motor is used which is more practical than the approximate linear model especially in the large motors. The authors also introduced a speed observer based on Lyapunov design and compared with another observer based on ANFIS design as well as the classical flux observer used with DTC technique. Simulation results show that the observers are validated and give a good performance in the different operating conditions. Also the authors have found that the ANFIS observer gives good performance as well as the Lyapunov and fuzzy observers.


Author(s):  
Elakhdar Benyoussef ◽  
Abdelkader Meroufel ◽  
Said Barkat

This paper presents a direct torque control is applied for salient-pole double star synchronous machine without mechanical speed and stator flux linkage sensors. The estimation is performed using the extended Kalman filter known by it is ability to process noisy discrete measurements. Two control approaches using fuzzy logic DTC, and neural network DTC are proposed and compared. The validity of the proposed controls scheme is verified by simulation tests of a double star synchronous machine. The stator flux, torque, and speed are determined and compared in the above techniques. Simulation results presented in this paper highlight the improvements produced by the proposed control method based on the extended Kalman filter under various operation conditions.


Resources ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 43 ◽  
Author(s):  
Nena Apostolidou ◽  
Nick Papanikolaou

In this work, the electromechanical system of the 8000-series of Athens trolleybuses, based on data provided by OSY S.A., is analyzed. Those data were used to develop a valid model in order to estimate the total energy consumption of the vehicle under any possible operating conditions. In addition, an effort is made to estimate the energy saving potential if the wasted energy—in the form of heat—during braking or downhill courses is recovered (regenerative braking) and retrofitted during normal operation. This process requires the installation of appropriate electrical apparatus to recover and temporarily store this energy amount. Moreover, due to the fact that the main engine of the system is an asynchronous electric machine, its driving scheme is also of interest. This study assumes the current driving scheme, that is the direct vector control (DVC), and proposes an alternative control method, the direct torque control (DTC). Energy consumption/saving calculations highlight the effectiveness of incorporating regenerative braking infrastructure in trolleybuses transportation systems. Finally, a sustainable hybrid energy storage unit that supports regenerative braking is proposed.


Author(s):  
Naveen Goel ◽  
Saji Chacko ◽  
R. N. Patel

The Direct Torque Controlled (DTC) induction motor (IM) drives over the years have been the work force of industries. The popularity of this motor drive is due to the low cost and low maintenance of induction motor coupled with the fast dynamic response and simple control structure of direct torque control method. The robust performance of the DTC induction motor drive depends on the proper tuning of its speed controller. The proposed paper make use of the stochastic optimization technique namely the popular Harmony Search Algorithm and is compared with the parameter free Jaya Algorithm for tuning the gains of the speed proportional integral controller. Simulation studies in MATLAB/Simulink shows the success of the Jaya Optimization for improving the performance of DTC drive with respect to speed and torque peak over shoot and steady state error under different drive operating conditions.


Sign in / Sign up

Export Citation Format

Share Document