J. L. Febin Daya

Implementation of Wavelet-Based Robust Differential Control for Electric Vehicle Application

This research letter presents the modeling and simulation of electronic differential, employing a novel wavelet controller for two brushless dc motors. The proposed controller uses discrete wavelet transform to decompose the error between actual and reference speed. Error signal that is actually given by the electronic differential based on throttle and steering angle is decomposed into frequency components. Numerical simulation results are provided for both wavelet and proportional-integral-derivate controllers. In comparison, the proposed wavelet control technique provides greater stability and ensures smooth control of the two back driving wheels.

A novel self - Tuning fuzzy based PID controller for speed control of induction motor drive

This paper presents a comparative study between a self-tuning fuzzy (STF) PID controller, Fuzzy Logic Controller and conventional PID controller based speed control system for a current source PWM inverter fed indirect field oriented control of Induction Motor (IM) Drives. In this work the conventional PI controller is replaced by self-tuning fuzzy PID based intelligent controller. The fuzzy logic controller employs different types of membership functions for each parameter for the efficient control of the drive system. The performance of the self-tuning fuzzy PID based controller is analyzed using digital simulation in MATLAB/Simulink. The results are compared with conventional PID and Fuzzy Logic Controller. The self-tuning fuzzy logic controller gives better results.

Analysis of Wavelet Controller for Robustness in Electronic Differential of Electric Vehicles: An Investigation and Numerical Developments

ABSTRACT In road transportation systems, differential plays an important role in preventing the vehicle from slipping on curved tracks. In practice, mechanical differentials are used, but they are bulky because of their increased weight. Moreover, they are not suitable for electric vehicles, especially those employing separate drives for both rear wheels. The electronic differential constitutes recent technological advances in electric vehicle design, enabling better stability and control of a vehicle on curved roads. This article articulates the modeling and simulation of an electronic differential employing a novel wavelet transform controller for two brushless DC motors ensuring drive in two right and left back driving wheels. Further, the proposed work uses a discrete wavelet transform controller to decompose the error between actual and command speed provided by the electronic differential based on throttle and steering angle as the input into frequency components. By scaling these frequency components by their respective gains, the obtained control signal is actually given as input to the motor. To verify the proposal, a set of designed strategies were carried out: a vehicle on a straight road, turning right and turning left. Numerical simulation test results of the controllers are presented and compared for robust performance and stability.

Wavelet transform with fuzzy tuning based indirect field oriented speed control of three-phase induction motor drive

This manuscript presents the details about the novel controller using wavelet transform and fuzzy logic tuning for speed control of an induction motor drive. The conventional proportional-integral (PI) speed controller in an indirect vector control of induction motor drive has been replaced by the proposed controller for an improved transient and steady state performances. The discrete wavelet transform has been used to decompose the error speed into different frequency components and the fuzzy logic is used to generate the scaling gains of the wavelet controller. The complete model of the proposed controller along with an induction motor drive incorporating the proposed controller has been developed in numerical simulation software using Matlab/Simulink environment and a set of results are provided within this paper in comparison to the conventional controller scheme.

A Modified Disturbance Rejection Mechanism in Sliding Mode State Observer for Sensorless Induction Motor Drive

This paper presents a modified sliding mode state observer for sensorless vector-controlled induction motor drive. The objective is to improve the dynamic performance of the sensorless drive subjected to parameter uncertainty, fault and disturbances. The sensorless drive along with the proposed observer is modeled and built in Simulink, and the dynamic behavior is obtained for different test cases such as flux-weakening region, variations in commanded speed and torque, low-speed operation and under faulty operation mode subjected to an electrical fault in the inverter. The conventional disturbance rejection mechanism is modified by constraining the estimated disturbance along with the stator current error in the sliding surface, thereby increasing the ability of the observer to reject the effect of the external load on the tracking performance. Extensive simulation results prove that the modified observer has a wide speed bandwidth compared to the conventional observer along with superior tracking, disturbance rejection characteristics and torque holding capability.

Dynamic performance analysis of MRAS based speed estimators for speed sensorless induction motor drives

MRAS estimators have become increasingly popular due to their ease of computational usage, flexibility and accurateness in determining the rotor speed of induction motors without speed sensors mounted on the shaft. This paper considers the three most popularly used configurations of MRAS Speed Estimators i.e., Rotor Flux, Back-EMF and Instantaneous Reactive power. The dynamic performance of the same is analyzed for different values of Load torque perturbations and is limited to medium and high speed range only. A mathematical model is presented for each estimator and an equivalent simulink model is built and the results are analyzed and inferences are drawn.

An Improved Stator Resistance Adaptation Mechanism in MRAS Estimator for Sensorless Induction Motor Drives

A comparative study of the conventional fixed gain PI and Fuzzy Logic based adaptation mechanisms for estimating the stator resistance in a Model Reference Adaptive System (MRAS) based sensorless induction motor drive is investigated here. The rotor speed is estimated parallely by means of a PI control based adaptive mechanism and the electromagnetic torque is also estimated to add more resilience. By considering the external Load torque perturbation as a model perturbation on the estimated stator resistance, the effects of the same on the estimated parameters are observed. The superiority of the Fuzzy based stator resistance adaptation mechanism is observed through detailed simulation performed offline using Matlab/Simulink blocksets. Furthermore, a sensitivity analysis of the stator resistance estimate with respect to load torque is also done to verify the effectiveness of the above concept.

Real-Time Analysis of a Nonlinear State Observer with Improved Disturbance Compensation for Sensorless Induction Motor

This paper presents a comparison and real-time analysis of sliding mode disturbance observers for speed sensorless induction motor drives. The rotor speed tracking bandwidth and the load rejection capability are improved by altering the profile of the sliding hyperplane used in the state observer. The entire system is built in Simulink environment, and real-time RT-lab blocksets are integrated into the same and tested in a new Processor-in-Loop-based test bench. The Processor-in-Loop test bench uses the OP4500 real-time target and loop back adapters for signal routing. This ensures that there is a real-world signal transfer between the plant and the controller.