S. Sathikumar

Bio: S. Sathikumar is an academic researcher from Indian Institute of Science. The author has contributed to research in topics: Voltage source & Vector control. The author has an hindex of 1, co-authored 1 publications receiving 24 citations.

Digital Simulation of Field-Oriented Control of Induction Motor

Abstract: This paper describes the simulation of a control scheme using the principle of field orientation for the control of a voltage source inverter-fed induction motor. The control principle is explained, followed by an algorithm to simulate various components of the system in the digital computer. The dynamic response of the system for the load disturbance and set-point variations have been studied. Also, the results of the simulation showing the behavior of field coordinates for such disturbances are given.

Modeling and simulation of induction machine vector control with rotor resistance identification

Abstract: This paper shows that it is possible to use available commercial software to model and simulate a vector-controlled induction machine system. The components of a typical vector control system are introduced and methods given for incorporating these in the MATLAB/SIMULINK software package. The identification of rotor resistance is important in vector control, if high-performance torque control is needed, and modeling of the extended Kalman filter (EKF) algorithm for parameter identification is discussed. It is certainly advisable, when feasible, to precede implementation of new algorithms, whether for control or identification purposes, with an extensive simulation phase. Additionally, a technique for generating pulse-width modulation (PWM) phase commands to extend machine operation to higher speeds before field weakening occurs is simulated in a vector-controlled induction machine, driven by a PWM inverter. This demonstrates the versatility of the vector-controlled induction machine system model.

Enhanced Predictive Torque Control for Open End Winding Induction Motor Drive Without Weighting Factor Assignment

Abstract: Nowadays, predictive torque control (PTC) is the most popular control technique in the field of electric drives. This PTC strategy is introduced for open end winding induction motor (OEWIM) drive in view of advantages. The conventional PTC offers a single-cost function where torque and stator flux control objectives are present. Since these control objectives are dissimilar, weighting factor designation to the respective control objective is essential. Weighting factor tuning by an empirical approach leads to a cumbersome control process. To overcome this tuning problem, this paper suggests a single control objective containing stator reference and predicted flux space vectors. This simplified proposed control scheme relieves PTC from weighting factor and facilitates combined torque and flux control. However, to control inverter switching frequency including torque and flux in a single cost function, weighting factors assignment and its proper tuning is indispensable. The proposed scheme is extended by replacing a single-cost function with separate multiobjectives and its optimization is achieved using a simple ranking analysis with limited prediction voltage vectors (VVs). This proposed feature permits PTC independent from weighting factors. Simulation and experimentation are performed on a dual inverter fed OEWIM drive. The achieved results are related with conventional PTC to verify the effectiveness of the proposed PTC.

A Simplified Predictive Torque Control Scheme for Open-End Winding Induction Motor Drive

Abstract: Variable speed induction motor (IM) drives with predictive torque control (PTC) technique is an advancing technology nowadays. The PTC technique is introduced for dual-inverter fed open-end winding IM (OEWIM) configuration owing to its benefits. The conventional PTC requires flux weighting factor assignment because of two different control objectives (torque and flux) in single cost function. This weighting factor selection plays a key role in selecting optimal voltage vector for better torque and flux response. Several analytical and empirical methods are introduced for optimal selection of weighting factor, which demands more computation time. This paper aims to develop modified PTC, eliminating flux weighting factor. The flux control objective is replaced by an equivalent reactive torque control. Thus making two control objectives of the same units and eliminating the requirement of flux weighting factor in cost function. Furthermore, nearest voltage vector selection strategy is introduced to limit the number of prediction voltage vectors in each sampling period. Thus, overall computational burden is reduced achieving minimum torque and flux ripples. The performance of the proposed PTC for multilevel inversion fed OEWIM is evaluated through MATLAB/Simulink simulations and experimental analysis. To highlight its benefits, these results are compared with those of the conventional and recent PTC techniques.

Microprocessor-Based Field-Oriented Control of A CSI-Fed Induction Motor Drive

Abstract: This paper describes the method of field orientation of the stator current vector with respect to the stator, mutual, and rotor flux vectors, for the control of an induction motor fed from a current source inverter (CSI). A control scheme using this principle is described for orienting the stator current with respect to the rotor flux, as this gives natural decoupling between the current coordinates. A dedicated micro-computer system developed for implementing this scheme has been described. The experimental results are also presented.

An Improved Direct Torque Control of Three-Level Dual Inverter Fed Open-Ended Winding Induction Motor Drive Based on Modified Look-Up Table

Abstract: The induction motor (IM) drive with direct torque control scheme (DTC) turns prominent for industrial applications. However, it retains disadvantage of high torque ripples. The conventional look-up table for DTC scheme is structured with selection of reverse voltage vectors (VVs) when flux and torque errors crosses lower hysteresis boundary condition. This results in higher torque ripples and increase in switching frequency. In this article, modified look-up table for DTC of three-level dual voltage source inverter fed open-ended winding IM drive is proposed, where the VVs selection for lower hysteresis boundary conditions of torque and flux are restructured with null voltage states. The selection of suitable null voltage switching states from the various possible combinations of dual inverter switchings is based on minimization of switching state transitions. To nullify flux instability at zero speed, proper active VVs are placed at hysteresis flux +1 and torque 0 condition in the modified look-up table. These overall effective modifications in the proposed DTC scheme enjoys the benefits of reduction in torque ripple, switching frequency, and stable flux maintenance. The MATLAB simulations and practical investigations are conducted for existing and proposed DTC schemes. From these results, the benefits of the proposed DTC over existing DTC schemes are verified.