Torque Control Of Motor Research Articles

Optimal Speed–Torque Control of Asynchronous Motor for Electric Cars in the Field-Weakening Region Based on Voltage Vector Optimization

In this article, model predictive (MP) and deep belief net (DBN) are introduced to optimize and predict the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> -axis stator voltage of asynchronous motors for electric cars in the field-weakening region to achieve the optimal “speed–torque” (represents the optimization of speed and torque performance) control. First, the analytical model of the maximum torque output is established, and the effect of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> -axis voltage on the torque output is analyzed. Second, to reduce the influence of proportional–integral parameter tuning, optimize the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> -axis voltage, and achieve the accurate torque control, MP is introduced to establish an analytical model of MP controller tracking current loop for generating the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> -axis voltage. Third, the maximum torque vector control system based on the MP controller is built, and the influence of system parameters on control effect is analyzed. Fourth, the simulation data are collected, and the DBN voltage prediction model is established. The model is embedded in the field-oriented control to achieve optimal “speed–torque” control. Finally, the dynamometer experimental platform is established to collect the experimental data and establish the DBN voltage prediction model. The validity of the method is verified through the voltage data calibration, “speed–torque” characteristic calibration, motor efficiency calibration, “speed–torque” response, and ripple test.

Torque Control of Interior Permanent Magnet Synchronous Motor Based on Online Parameter Identification Using Sinusoidal Current Injection

Interior permanent magnet synchronous motor (IPMSM) is applied in automotive drive because of its high efficiency and high power density. The accurate torque control of motor, however, is still subject to further investigation and improvement. In order to improve the performance of IPMSM applied in electric vehicles, a feedback torque control method based on online parameter identification is developed in this research. In order to control the instantaneous electromagnetic torque accurately, stator resistance, rotor flux, and dq-axis inductance are identified simultaneously with a recursive least square algorithm. In this process, sinusoidal disturbance current is injected into d-axis to solve the rank-deficient problem. Furthermore, a simulation model is developed based on this torque control method. The simulation results show that the torque control method developed in this research can perform better than the torque control method based on fixed parameters. On the other hand, a test rig is developed in this research to verify the feasibility of torque control method and the effectiveness of simulation model. The measured results show that these parameters can be identified accurately with the online parameter identification method developed in this research, and the robustness of this online parameter identification method can be verified in the experiment. Furthermore, the torque control method is verified with this test rig, and the results show that the measured torque can accurately follow the torque command rapidly with little fluctuation, indicating that the method developed in this research has the features of high accuracy, high robustness and short response time.

FPGA Hardware in the Loop Validation of Asynchronous Machine with Full Direct Torque Control Implementation

This article provides a full hardware implementation for direct torque control (DTC) of an asynchronous motor (AM) on the Field Programmable Gate Array (FPGA). Due to its high processing frequency, the FPGA circuit presents an alternative for achieving a high performance DTC implementation. This cannot be achieved by any DSP or microcontroller application. The proposed hardware architecture implements three components of DTC control strategy (the integral proportional speed regulator, the estimation and the switching blocks). This implementation has the advantage of being faster, more efficient and with minimum hardware resources on the target FPGA board. The hardware architecture of the DTC control was designed and simulated in Matlab / Simulink using XSG blocks, then synthesized with the Xilinx ISE 14.2 tool, implemented and validated on the Xilinx Virtex-4 FPGA circuit by Hardware in the Loop process.

Influence of the stator current reconstruction method on direct torque control of induction motor drive in current sensor postfault operation

Influence of the stator current reconstruction method on direct torque control of induction motor drive in current sensor postfault operation

Enhanced Intelligent Closed Loop Direct Torque and Flux Control of Induction Motor for Standalone Photovoltaic Water Pumping System

This paper aims to search for a high-performance low-cost standalone photovoltaic water pumping system (PVWPS) based on a three-phase induction motor (IM). In order to control the IM, a fuzzy direct torque control (FDTC) is proposed in this paper for overcoming the limitations of the conventional direct torque control (CDTC). In fact, the CDTC suffers from several problems such as torque ripples, current distortion, and switching frequency variations. These problems can be solved with the proposed FDTC. To ensure high performance of the PVWPS, the reference torque is generated using a fuzzy speed controller (FSC) instead of a conventional proportional integral speed controller. In order to extract the maximum amount of power, the proposed maximum power point tracking controller is based on variable step size perturb and observe to surmount the weakness of the conventional perturb and observe technique. The performance of the proposed FDTC based on the FSC under variable climatic conditions is demonstrated by digital simulation using Matlab/Simulink. The obtained results show the effectiveness of the suggested FDTC based on the FSC compared with the CDTC in terms of pumped water, reduction in flux and torque ripple, diminution of losses, and decrease in the stator current harmonic.

A novel direct torque and flux control of permanent magnet synchronous motor with analytically-tuned PI controllers

&lt;span lang="EN-US"&gt;This work presents a novel direct torque and flux control (DTFC) of permanent magnet synchronous motor (PMSM) with analytically-tuned proportional integral (PI) controllers. The proportional (K_p) and integral (K_i) gains of the PI controllers were accurately determined, from first principle, using the model of the control system. The PI flux and torque controllers were then developed in rotor reference frame. The designed PI controllers, together with the torque and flux controllers, were tested on a permanent magnet synchronous motor (PMSM). The results obtained were compared with results from conventional DTFC system using manually-tuned PI controllers. The total harmonic distortion (THD) of motor phase currents is 18.80% and 4.81% for the conventional and proposed models respectively. This confirms a significant reduction in torque ripples. The control system was tested for step torque loading and found to offer excellent performance both during load changes, speed reversal, and constant load conditions.&lt;/span&gt;

Multi-carrier switching strategy for high-bandwidth potential balancing control of multilevel inverters

&lt;span lang="EN-US"&gt;This paper confers on investigation of a direct torque control (DTC) of induction motor drive by 3 level neutral point clamp (NPC) multilevel inverter. The imbalance problem may deteriorate the electric drive performances which might cause a short circuit condition. Various balancing control strategies were proposed, however, most of them employed complex space vector modulation (SVM) and hysteresis-based controller that generates variable switching frequencies. The proposed method will offer a reliable balancing control strategy with a constant switching frequency, and moreover, it will provide excellent electric drive performances. This research proposed a new multi carrier switching modulation strategy that establish a high-band-width control for neutral point potential in the NPC inverter. Potency of the proposed high-bandwidth potential balancing strategy is validated through the MATLAB/SIMULINK environment.&lt;/span&gt;

Predictive Torque Control of Five-Phase Induction Motor Drive Using Successive Cost Functions for CMV Elimination

This article presents a predictive torque control (PTC) algorithm for a five-phase (distributed winding) induction motor fed by a three-level neutral-point-clamped inverter to remove the common-mode voltage (CMV). In this approach, a finite range of 31 voltage vectors (VVs) is chosen from the total available 243 VVs for the removal of the CMV. The xy-subspace current harmonic reduction is achieved with grouped VVs. The developed PTC algorithm has two successive cost functions: g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1h</sub> for stator flux and electromagnetic torque regulation and g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2h</sub> for xy-subspace current harmonic reduction. The purpose of these two successive cost functions is to reduce the complexity in determining the independent weighting factors. This algorithm retains the torque and flux responses similar to that of conventional PTC. The minimization in switching frequency is obtained in the presented PTC algorithm with the selected set of VVs. For evaluating and ascertaining the capabilities for CMV elimination and xy-subspace harmonic current reduction, the proposed algorithm is compared with the conventional PTC algorithm having a different set of VVs. Experimental outcomes show the significance of the discussed algorithm in the steady state and retain the transient operating conditions.

Regulation of Electric Vehicle Speed Oscillations Due to Uneven Drive Surfaces Using ISMDTC

An unbalance in the electromagnetic torque and the load torque occurs when Electric Vehicles (EVs) are driven through uneven terrains. This leads to non-periodic and time-varying speed oscillations. As a result, torsional vibrations increase and leads to passenger discomfort and mechanical stress on the EV body. The EV drive control should be designed to mitigate these speed oscillations. In this paper, an Integral Sliding Mode Control Based Direct Torque Control (ISM-DTC) of Induction Motor (IM) is proposed to inherit the intrinsic properties of disturbance rejection, robustness against parametric variations, operational uncertainties, and improve the conventional Proportional-Integral (PI)-based DTC (PIDTC) performance in uncertain EV drive conditions. The proposed control is integrated with PIDTC, which maintains the speed and acts as a nominal control. The non-linear ISM loop cancels out the speed fluctuations by balancing the electromagnetic torque with dynamic load torque demand. The proposed control cancels out the matched uncertainties without amplifying the unmatched uncertainties in system dynamics. An analysis of the uncertainty decomposition and control gain derivation is presented. The proposed ISMDTC is verified through simulations and experiments considering different scenarios of torque, reference speed variations, uncertainties, and the standard New European Driving Cycle (NEDC) and Urban Dynamometer Driving Schedule (US) drive test cycles.

Research on Direct Torque Control of Permanent Magnet Synchronous Motor for New Energy Vehicles

This article introduces the control principle, technical status and two commonly used motor control schemes of permanent magnet synchronous motors for new energy vehicles. Direct torque control is selected as the research object, and its advantages and disadvantages with vector control are analyzed. A Simulink simulation model was established according to the control principle.

Three-level inverter-fed model predictive torque control of a permanent magnet synchronous motor with discrete space vector modulation and simplified neutral point voltage balancing

Three-level inverter-fed model predictive torque control of a permanent magnet synchronous motor with discrete space vector modulation and simplified neutral point voltage balancing

Direct torque control of induction motor with different energy storage for electrical vehicle (EV) application

Energy demand worldwide is rising at an unprecedented pace. This has already shown its impact on the depletion of energy sources and environmental issues (global warming and the weakening of the ozone layer). This growing pattern of energy insufficiency will, of course, intensify in the future. Referring to the literature, significant energy savings can be achieved by controlling the speed of the electric motor system using variable frequency drives (VFDs). Efficient control of induction motor drives provides an excellent opportunity for energy savings. As a result, research into the optimal operation of induction motor drives is escalating and mainly focuses on the Direct Torque Control (DTC) control technique on improving the dynamic operation of torque control. However, the study on the type of energies on improving the dynamic response is least reported. This paper will study the effect of different energy supplies on the dynamic response of torque performance. The standard DC battery and supercapacitor will be used to energize the induction motor through the three-phase inverter and controlled with the DTC control scheme. The results are validated through MATLAB Simulink and it shows the supercapacitor has the better dynamic response in torque response compared to the standard DC battery. The comparative results are presented in a proper mannered way.

FPGA Hardware in the Loop Validation of Torque and Flux Estimators for Direct Torque Control (DTC) of an Induction Motor (IM)

FPGA Hardware in the Loop Validation of Torque and Flux Estimators for Direct Torque Control (DTC) of an Induction Motor (IM)

Load torque control of an electromagnetic motor with a reduction gear and motor/load‐side encoders using a spring model including a dead zone

AbstractActuators with characteristics such as light weight, a high torque/weight ratio, and a high torque control performance are desired for contact tasks using robots. Although electromagnetic motors with gears have these features, friction in gears degrades the torque control performance. Therefore, in this study, the load torque control performance is improved by utilizing motor/load side angle information. Both the torque controller and the load torque observer in the proposed control system utilize motor/load side encoders and the spring model, which includes a dead zone. The dead zone model represents the backlash between the motor output shaft and the reducer output shaft. A simulation and experiment show the efficacy of the proposed control system.

Direct Torque Control of Induction Motor Based on Particle Swarm Optimization

Induction Motor (IM) is most commonly used in different industrial applications, that require fast dynamic response and accurate control over wide speed ranges. Therefore, this paper proposes high performance Direct Torque Control (DTC), which is closed loop control system to improve the dynamic performance of IM. The main objective of this work is to improve the speed response of IM during different load and speed conditions. Proportional-Integral (PI) controller based on Particle Swarm Optimization (PSO) technique is used for optimal gains tuning. The results show the improvement in the speed response of DTC using PSO technique when compared with conventional PI and the conventional DTC (without PI), in terms of reducing steady state error, settling time, overshoot and ripple reduction which make this controller more robust to variation in load and speed. The simulation of the overall drive system is performed using MATLAB/Simulink program version 7.10 (R2010a).Keywords: Induction Motor (IM), Direct torque control, PI controller and Particle Swarm Optimization (PSO).

Sensorless fuzzy direct torque control of induction motor with sliding mode speed controller

In this work, a fuzzy direct torque control (DTC) is developed for asynchronous motor drive powered by two-level inverter. The main objective is to enhance the system performance by reducing electromagnetic torque and stator flux ripples while improving stator current waveforms. The hysteresis comparators and voltage vector switching table of classic DTC are replaced by fuzzy logic block to ensure robust control against various disturbances. The outer speed loop is initially executed by PI regulator and secondly by sliding mode controller, for both systems stator flux MRAS estimator is adopted. A critical and comparative study between the DTC based on fuzzy logic and non-linear sliding mode DTC was done under MATLAB/SIMULINK. The performance analysis was carried out under different operating conditions such as steady and transient states, low , medium and high speeds, speed reversal and application of two different loads at various times.

Load Torque Control of an Electromagnetic Motor with a Reduction Gear and Motor/Load-side Encoders Using a Spring Model including a Dead Zone

Load Torque Control of an Electromagnetic Motor with a Reduction Gear and Motor/Load-side Encoders Using a Spring Model including a Dead Zone

Two‐stage DSVM‐based torque ripple minimisation technique for the predictive torque control of the induction motor

In this study, a two-stage technique is proposed for reducing torque ripple in the Predictive Torque Control (PTC) of the induction motor, based on the Discrete Space Vector Modulation (DSVM) strategy. In the first stage of this method, the voltage vectors are appropriately arranged through an offline procedure, such that the torque ripple value is decreased. On the other hand, the application time of the voltage vectors during the sampling period is calculated in the second stage, by conducting some online calculations, based on the adjacent vectors of the DSVM technique. This results in further torque ripple reduction. The proposed method can effectively reduce the torque ripple value at different operating points, especially at lower speeds. Finally, to validate the proposed method performance, the control algorithm has been experimentally implemented for an induction motor fed by 2L-VSI; and it is compared with two-vector PTC and deadbeat approaches.

Оптимизация пульсаций момента двигателя в электроприводе с прямым управлением

The article discusses the features of the synthesis of a hybrid method for commutation of a three-phase inverter in a classic version of drives with direct torque control (DTC), which involves the use of relay characteristics in the flux- and torque control blocks. It is proved that the output voltage of a converter based on a B6-inverter formed by only six basic vectors (excluding the zero vector) limits further optimization of flux- and torque ripples in the electrical motors. It has also been proven that with the classical drives with direct torque control, the torque ripples on the motor shaft are indeed higher than in systems with pulse width modulation. An analysis of the method was carried out which could allow reducing the amplitude of the torque ripples when drives with direct torque control are applied for motors supplied with only basic vectors of the inverter due to the modified (hybrid) method of inverter commutation. The conditions under which the hybrid control method of the inverter is really capable of reducing the amplitude of the motor flux- and torque ripples are considered. Based on the analysis of the proposed solution, the law of hybrid control of the inverter is presented by means of the formation of additional vectors of its output voltage via basic vectors of the inverter. The advantages of the method include the simplicity of drive control under development or in the existing drive control system, the implementation of which is carried out exclusively by a software product. With the absence of iterative methods of mathematics, the resources of microprocessor control units are reduced, which makes this method even more attractive in low-budget electrical drives that do not claim to be "high-end" of control blocks. The oscillograms are shown of a flux and current of motor with direct torque control motor application only with six base vectors of the output voltage of a semiconductor inverter and a drive with direct torque control by the hybrid method with additional voltage vectors based on the basic vectors of the inverter.

Predictive torque control of induction motor drive with reduction of torque and flux ripple

Predictive torque control of induction motor drive with reduction of torque and flux ripple