Direct Torque Control With Space Vector Modulation Research Articles

Fault tolerant control of permanent magnet synchronous motor based on hybrid control strategies DTC-SVM with second order sliding mode control using multi-variable filter

This paper describes direct torque control (DTC) of a permanent magnet synchronous machine (PMSM) powered by a two-level voltage inverter whose switching of switches is based on the Space Vector Modulation. To overcome the robustness of the control to the presence of a fault, we included an improvement of the direct torque control with Space vector modulation (DTC-SVM) by the use of the filters for the flux and the torque and compared to the direct torque control of the DTC-SVM, the PI controllers are replaced with sliding mode blocks, This control method allows giving a new structure DTC -SVM with sliding mode control. The analysis of the results shows good performances for the speed and a considerable reduction of the fluctuations at the level of the torque and the flux.

Analysis of the Drive of the Electric Vehicle with Six-Phase Induction Motor

Abstract The article presents the analysis of the drive system of the electric vehicle with a six-phase induction motor. The mathematical models of the six-phase induction motor and model reference adaptive system (MRASF) estimator are presented, and the description of the voltage source inverter, space vector modulator and bidirectional buck–boost converter is shown. The direct field-oriented control (DFOC) system and the direct torque control with space vector modulation (DTC-SVM) system are analysed. Results of simulation studies of these control methods and comparative analysis are shown. The DTC-SVM method is selected as the method with the best properties, and a full model of the electric vehicle drive system is built using this method. The detailed description of the drive system of the electric vehicle with a six-phase induction motor and DTC-SVM control system and the results of simulation tests for this drive system are presented. The aim of the authors and an element of novelty is to develop and test a drive system for an electric vehicle with a six-phase induction motor, adaptive speed estimator and extensive space vector modulator.

An Improved Torque Control Strategy of PMSM Drive Considering On-Line MTPA Operation

An improved direct torque control with space-vector modulation (DTC-SVM) scheme is presented in this paper. In the conventional DTC-SVM scheme, torque control performance is affected by the load conditions, due to the inappropriate linearization of the relationship between the flux angle and electromagnetic torque. Different from the conventional method, a torque controller with load angle estimation (TC-LAE) is proposed and the change rate of torque is regulated according to the variation of the load conditions, which could ensure the rapidity and consistency of torque performance at different load conditions. Meanwhile, an online permanent magnet synchronous motor and maximum torque per ampere (PMSM-MTPA) operation strategy based on the fitting solving method is proposed instead of the traditional two-dimensional look-up table, and the reference value of flux amplitude is calculated online to meet the MTPA requirement with the proposed method. The improved strategy is applied on a 6 kW PMSM, and the simulation and experimental results verified the effectiveness and the feasibility of the proposed strategy.

A practical framework for tuning DTC-SVM drive of three-phase induction motors

This paper presents a framework for tuning the proportional-integrative (PI) controllers of a direct torque control with space vector modulation (DTC-SVM), applied to a three-phase induction motor. For flux and torque loops, the PIs are designed considering frequency response methods in terms of phase margin and 0dB crossover frequency. In special for the speed loop, the Symmetric Optimum Criterion (SOC) is considered for adjusting the PI gains. Simulation and experimental results are obtained aiming at evidencing the effectiveness of the considered methodology.

An improved sensorless DTC-SVM for three-level inverter-fed permanent magnet synchronous motor drive

A speed-sensorless control strategy is investigated in a wide speed range based on extended Kalman filter (EKF) and direct torque control with space vector modulation (DTC-SVM) for three-level cascaded H-bridge inverter-fed permanent magnet synchronous motor drives. The implementation of conventional SVM technique to the multilevel inverters is considerably complicated and leads to high computational burden. A three-level SVM technique simplified on the basis of two-level voltage vector diagram is proposed to reduce this computational complexity, and in addition, to satisfy some requirements for the safe operation of the inverter such as smooth commutation and minimum number of switching. The estimations of rotor position and speed are achieved using an EKF without high-frequency signal injection, especially at very low and zero speeds. The load torque is also estimated simultaneously to account for the mechanical frictions at steady state to improve the estimation performance. Furthermore, the flux trajectory control based on maximum torque per ampere algorithm is implemented to ensure maximal efficiency for constant torque region. The feasibility and effectiveness of the proposed drive system is tested under different operating conditions and verified by the simulation results.

Improved Modified DTC-SVM Methods for Increasing the Overload-capability of Permanent Magnet Synchronous Motor Servo- and Robot Drives – Part 1

Direct torque control with space vector modulation (DTC-SVM) is one of the most popular methods in the case of permanent magnet synchronous motor drives due to its excellent torque-control capabilities. This method facilitates a very high torque-control dynamic performance which is an especially important requirement in the field of servo- and robotic applications, thus making DTC-SVM a natural choice in these cases. In this article a novel Improved Modified DTC-SVM (IMDTC-SVM) method is presented and it is proven that this method has a very high overload-capability and is stable during overload-conditions, while the torque-control dynamics and the torque-ripple generated are practically identical with those of the classical DTC-SVM and the MDTC-SVM.

Improved Modified DTC-SVM Methods for Increasing the Overload-capability of Permanent Magnet Synchronous Motor Servo- and Robot Drives – Part 2

Direct torque control with space vector modulation (DTC-SVM) is one of the most popular methods in the case of permanent magnet synchronous motor drives due to its excellent torque-control capabilities. This method facilitates a very high torque-control dynamic performance which is an especially important requirement in the field of servo- and robotic applications, thus making DTC-SVM a natural choice in these cases. In this article simplified forms of the Improved Modified DTC-SVM (IMDTC-SVM) method that has been introduced in Part 1 are presented and it is proven that these methods have a very high overload-capability as well, they are stable during overload-conditions, while the torque-control dynamics and the torque-ripple generated are practically identical with those of the classical DTC-SVM, the MDTC-SVM and the standard IMDTC-SVM. Although the simplified forms have a somewhat lower overload-capability than that of the standard IMDTC-SVM, they have a significantly simpler structure, they require much less computation and the tuning of the complete control system is in one case much simpler.

DIRECT TORQUE CONTROL OF MULTI-PHASE INDUCTION MOTOR WITH FUZZY LOGIC SPEED CONTROLLER

The paper presents the Direct Torque Control with Space Vector Modulation (DTC-SVM) of seven-phase induction motor with Fuzzy Logic Speed Controller. The mathematical model of the seven-phase squirrel-cage induction motor and chosen methods of Space Vector Modulation have been presented. Simulation studies of the DTC-SVM with Fuzzy Logic speed controller have been carried out and the results of simulation studies have been presented and discussed. The author original contribution includes analysis and studies of considered control method of seven-phase induction motor.

DTC-SVM Control for Permanent Magnet Synchronous Generator based Variable Speed Wind Turbine

<span lang="EN-US">In this paper, we are interested in improving the production efficiency for electric energy extracted from a wind turbine, based on a permanent magnet synchronous generator (PMSG) that we want to improve the performance by means of direct torque control with space vector modulation (DTC-SVM). The choice of this control comes from the deficiencies inherent to the conventional DTC, which includes variable switching frequency, torque ripple and implementation complexity. First we focuse on the wind energy conversion system (WECS) modeling using the PMSG machine, as well as the detailed study for the control DTC-SVM operating principle. Then, system performance is tested and compared by simulation in the MATLAB/Simulink in terms of follow instructions, robustness to the variations of the external system elements, and effectiveness of the expected method.</span>

Metaheuristics optimization applied to PI controllers tuning of a DTC-SVM drive for three-phase induction motors

This paper presents the application of optimization metaheuristics in direct torque control with space vector modulation (DTC-SVM) of a three-phase induction motor. Two metaheuristic algorithms are considered: Ant Colony Optimization (ACO) and Differential Evolution (DE). These techniques are considered in order to achieve an optimized tuning of proportional-integral (PI) controllers in the DTC-SVM control loops, such as rotor speed, electromagnetic torque, stator flux linkage and estimation of the linkage stator flux. Hence, the paper aims to contribute to adjusting the PI controllers of DTC-SVM. All the optimization procedure is performed via computer simulation. Once the optimized gains are obtained, they are applied to the practical system developed herein. Simulation and experimental results are presented in order to validate the approach proposed.

A Novel Modified DTC-SVM Method with Better Overload-capability for Permanent Magnet Synchronous Motor Servo Drives

Direct torque control with space vector modulation (DTC-SVM) is one of the most promising alternatives of field-oriented control in the case of permanent magnet synchronous motor drives. This method controls the electromagnetic torque of the motor with excellent dynamics which makes it an attractive choice in the case of servo drives. In this article DTC-SVM is investigated with Matlab-Simulink simulation and it is proven that DTC-SVM has severe instability-issues during overloading and its overload-capabilities are heavily dependent on the speed. Therefore, a novel modified DTC-SVM method is proposed which is stable during overloading and its overload-capabilities are practically independent of the speed. Also, the overload-capability of the new method is superior to that of classical DTC-SVM, while the two methods are practically identical from the point of view of the torque-control dynamics and the torque-ripple generated.

Simple speed sensorless DTC-SVM scheme for induction motor drives

Abstract The paper focuses on the development of a novel DSP based high performance speed sensorless control scheme for PWM voltage source inverter fed induction motor drives. Firstly, two generic torque and flux control methods the Field Oriented Control (FOC) and Direct Torque Control (DTC), are briefly described. For implementation the sensorless scheme DTC with Space Vector Modulation (DTCSVM) has been selected because it eliminates the disadvantages associated with the DTC while keeping the advantages of both FOC and DTC. Secondly, the simple flux vector observer allowing speed sensor elimination is given. The novelty of the presented system lays in combining the DTC-SVM structure with a simple observer for both torque/flux and speed sensorless control. Furthermore, the DTC-SVM structure which operates in speed sensorless and torque control mode is presented. Finally, the description of a 50 kW laboratory drive and experimental results illustrating properties of the system are given.

A Position Sensorless Method for Direct Torque Control With Space Vector Modulation of Hybrid Excitation Flux-Switching Generator

A position sensorless method for direct torque control with space vector modulation (DTC-SVM) of hybrid excitation flux-switching generator (HEFS) is presented. Based on the synchronous angular frequency acquired by a m-order low-pass filter, a programmable first-order low-pass filter together with a band pass filter and a coordinate transformation is used to estimate the stator flux-linkages without magnitude and phase angle errors. Thus, the instantaneous torque and the rotor position can be accurately estimated based on the precise stator flux-linkages. The DTC-SVM scheme of the HEFS using the proposed position sensorless method exhibits good steady-state and dynamic performance, which is verified by experimental results.

Simulation and Implementation of a High Performance Torque Control Scheme of IM Utilizing FPGA

Thi paper presents a novel approach to design and implementation of a high perfromane torque control scheme i.e. direct torque control with space vector modulation(DTC-SVM) of three phase induction motor using Field Programmable gate array (FPGA). The conventional direct torque control (DTC) is one of control scheme that is used commonly in induction motor control system. This method supports a very quick and precise torque response. However, the conventional DTC is not perfect and has some disadvantages. To minimize the ripples of the electromagnetic torque and flux linkage and to fix the variable switching frequency produced in the conventional DTC, this paper proposes improved DTC-SVM concept. Both simulation and experimental results show that the proposed scheme can dramatically improve the steady state performance while preserving the dynamic performance of the conventional DTC.

Dynamically Reconfigurable Control Struture for Three Phase Induction Motor Drives

Field Programmable Gate Arrays (FPGAs) are a suitable hardware platform for the industrial control systems. These dynamically reconfigurable FPGAs can be used as an alternative digital solution to conventional microcontrollers and DSPs to ensure fast operation. This paper presents the feasibility of embedding the Direct Torque Control with Space Vector Modulation (DTC-SVM) of an induction motor into FPGA.The DTC-SVM of induction motor drives is simulated in a Matlab/Simulink environment using a Xilinx System Generator. DOI: http://dx.doi.org/10.11591/ijpeds.v2i1.183