Analysis of fuzzy and neural controllers in direct torque controlled synchronous motors (original) (raw)
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In recent times, permanent magnet synchronous motors (PMSM) have gained numerous industrial applications, because of simple structure, high efficiency and ease of maintenance. But these motors have a nonlinear mathematical model. To resolve this problem several studies have suggested the application of vector control (VC) and direct torque control (DTC) with softcomputing (SC) techniques. This paper presents neuro direct torque control (NDTC) of PMSM. Hence this paper aims to present a technique to control torque with reduced ripple compared to previous techniques. The outputs of Artificial Neural Network (ANN) controller mechanism is compared with that of classical DTC and the results demonstrate the influence of ANN is improved compared to classical DTC topology. The system is also verified and proved to be operated stably with reduced torque ripple, sudden speed reversals, at low torque and at high torque. The proposed method validity and effectiveness has been verified by computer simulations using Matlab/Simulink®. These results are compared with the ones obtained with a classical DTC using PI speed controller.
PI-Like Fuzzy Logic Direct Torque Control of Permanent Magnet Synchronous Motor
2014
In this paper, the modeling of the Direct Torque Control (DTC) system of permanent magnet synchronous motor (PMSM) based on Matlab/Simulink environment is presented. Simulation results are introduced to predict the motor drive system performance and the effect of PI-like fuzzy controller parameters on speed response in this system. The simulation results show that the torque ripple can be reduced by narrowing the torque hysteresis loops width.
Direct Torque Control of a Permanent Magnet Synchronous Motor using Fuzzy Logic
2007
During a long time, permanent magnet synchronous motor (PMSM) were only reserved for some specific applications, however, recently, these machines are becoming more used due to the powerful magnetic characteristic of the rare earth, being used in different areas. Several researchers have proposed implementations combining the use of permanent magnet synchronous motor with the direct torque control (DTC) technique offering
Control Engineering and Applied Informatics
The two important disadvantages of Direct Torque and Flux Control (DTC), are torque and flux ripples and stator resistance variation (which affects seriously the estimation stator flux and electromagnetic torque). This paper proposes a fuzzy-logic based DTC (FLC) using modified switching table for permanent magnet synchronous motor (PMSM) and Fuzzy-logic Resistance Estimator. The high-performance of the proposed FLC applied to PMSM drive, are investigated and compared with traditional DTC. The proposed system has proven successful in controlling the instantaneous torque so as not to depend only on the estimation flux, torque and position, but also on variable amplitude torque hysteresis bands and stator resistance (r s) delivered by fuzzy-logic.
The International Journal of Advanced Manufacturing Technology, 2016
Direct torque control (DTC) of permanent magnet synchronous motor (PMSM) drives is receiving increasing attention due to important advantages, such as fast dynamic and low dependence on motor parameters. However, conventional DTC scheme, based on comparators and the switching table, suffers from large torque and flux ripples. In this paper, two intelligent approaches are proposed in order to improve DTC performance. The first approach is based on two adaptive fuzzy logic controllers (AFLC). The first AFLC replaces the conventional comparators and switching table and the second AFLC adjusts in real time the outer loop PI parameters. In the second approach, particle swarm optimization (PSO) is used as another alternative to adjust the PI parameters. Simulation and experimental results demonstrate the effectiveness of the proposed intelligent techniques. Besides, the system associated with these techniques can effectively reduce flux and torque ripples with better dynamic and steady state performance. Quantitatively, PSObased DTC approach reduces greatly flux and torque ripples. Further, PSO-based approach maintains a constant switching frequency which improves the PMSM drive system control performance.
DIRECT TORQUE CONTROL OF PMSM USING FUZZY LOGIC WITH PWM
Since its development, Permanent Magnet Synchronous Machines (PMSM) has been used in a number of specific applications. However, in recent years PMSMs have become more attractive due to developments in new materials for permanent magnets and in semiconductor technology for converter design. Recent investigations have proposed some implementations applying the Direct Torque Control (DTC) technique to PMSM motor drives, offering a fast and accurate control. This paper presents a modified DTC scheme, using fuzzy logic with Pulse Wide Modulation (PWM) to improve stator flux and the electric torque by significantly reducing their ripple. The proposed method effectiveness has been verified by computer simulations and experimental tests on a laboratory prototype. These results are compared with the ones obtained with a modified DTC using a PI controlled PWM with current limit.
2000
During a long time, permanent magnet synchronous motor (PMSM) were only reserved for some specific applications, however, recently, these machines are becoming more used due to the powerful magnetic characteristic of the rare earth, being used in different areas. Recently several researchers have proposed implementations combining the use of permanent magnet synchronous motor with the direct torque control (DTC) technique
Journal of Control Engineering and Applied Informatics, 2014
In this paper, Direct Torque and Flux Control (DTFC) method based on Space Vector Modulation (SVM) technique is designed for a Line-Start Permanent Magnet Synchronous Motor (LSPMSM) and its equal Permanent Magnet Synchronous Motor (PMSM). In addition, the LSPMSM is designed using finite element analysis. Moreover, the same Fuzzy Logic Controllers (FLCs) with minimum simple triangle membership functions and reduced rule bases are designed and used. In order to present a thorough comparison, the same conditions are tested for both motors. Simulation results from MATLAB/Simulink software are presented for independent control of torque and flux motor parameters, and the advantages of the proposed method for the LSPMSM over the PMSM are analyzed.
A Modified Direct Torque Control Scheme for Permanent Magnet Synchronous Motor Drives
This paper presents a Direct Torque Control (DTC) scheme for permanent magnet synchronous motor (PMSM) drive. The proposed scheme was designed to overcome the main disadvantage of the conventional DTC – the high torque ripple generated in steady state operation. For this purpose, the voltage level at the inverter output is modified according to the instant values of the torque error and the stator flux angle. Every sample time, a reference voltage vector is calculated, in terms of magnitude and phase, and applied to the inverter using the Space Vector Modulation technique. The reference voltage vector is calculated using a simple algorithm, which preserves the principle of the conventional DTC regarding the decoupled torque and flux control. Numerical simulations have been made to test the proposed method and results are presented for a set of operating points.
Fuzzy inference system based direct torque control
In this paper, two controllers are designed for a direct torque control of an induction machine and validated on a voltage-source pulse width modulation inverter-fed induction motor drive. Basically, it is a task of replacing the classical Direct Torque Control strategy (DTC) by a Direct Torque Fuzzy Control strategy (DTFC) based fuzzy controller. The aim of this work is to reduce the torque and the flux ripples caused by the hysteresis controllers and the selection table in the classical DTC and to require low current in the start-up by fluxing the machine when the torque is maintained zero. In this manner, the proposed method is incorporated in the classical DTC scheme in order to replace both hysteresis controllers and the selection table. In this context, an evaluation study is carried out to demonstrate the effect of the stator resistance variation on the torque and flux ripples, the robustness of these controllers in the transients at the start-up of the machine or when changing its rotary direction and the behaviour of the flux response when the torque is zero. In this context, this case study is carried out to justify the benefits of the fuzzy controller and its advantages over the classical one. In effect, computer simulations validate the proposed method, support its ability to follow desired dynamics and show good performance even in the low speed range, where the stator resistance influence becomes critical.