State-dependent sliding mode control for three-phase induction motor drives

This research focuses on investigation and evaluation of the robust speed control for threephase induction motor. A sliding mode control, which offers great potential to deal with uncertainties such as parameter variation and external load disturbances, is examined. The main obstacle of conventional sliding mode control is caused by discontinuous function of high control activity which is known as chattering phenomenon. In this research, this chattering phenomenon is significantly reduced by a newly developed algorithm. A fast sigmoid function with varying boundary layer algorithm is designed as a state-dependent to replace the discontinuous function in conventional sliding mode control as well as to avoid steady state error compare with the use of fixed boundary layer. It is known that the switching gain of sliding mode control is proportional to the chattering level, and normally a large switching gain is applied to handle the uncertainties. This research proposes a state-dependent sliding mode control which is the switching gain is proportional to the sigmoid function of the sliding mode controller. As a result, the boundary layer and the switching gain will change depending on uncertainties of the motor drives system. In this research, the induction motor is controlled by vector control strategy, using indirect field orientation and Space Vector Pulse Width Modulation technique. Simulation result have proved that the proposed state-dependent sliding mode control was able to deal with external load disturbances as well as effectively free from chattering phenomenon compared to conventional sliding mode control. Finally, experimental investigation is performed in order to confirm the theoretical and simulation findings. The proposed algorithm and the vector control strategy are developed in digital signal processing board. The experimental results have confirmed that the state-dependent sliding mode control is superior with regard to external load disturbances and variation in the reference speed setting when compared to PI speed control and conventional sliding mode control

COMPARISON PERFORMANCE OF INDUCTION MOTOR USING SVPWM AND HYSTERESIS CURRENT CONTROLLER

This paper presents the comparative performances of three phase induction motors using space vector pulse width modulation (SVPWM) and hysteresis current controller. An indirect field orientation is applied to ensure decoupling control between torque and flux of the induction motor. The hysteresis current controller is built in with PI speed controller and three hysteresis current bands while the SVPWM system is embedded with the two control loops, the inner current control loop and the outer speed control loop using PI controller. Both systems were run and tested using MATLAB/SIMULINK software. The simulation results demonstrate that the SVPWM can improve the quality of the stator current and reduce the torque ripple while maintaining the other performance characteristics of the system

A New State-Dependent of Sliding Mode Control for Three-Phase Induction Motor Drives

Abstract - Chattering is known as a main obstacle in realizing sliding mode control. In this study, new robust and chattering suppression of sliding mode control method is investigated. First, an integral sliding mode control is developed. Then, a simple smooth function and switching gain with state-dependent based on fast sigmoid function is introduced. This method allows chattering reduction, as well as maintaining the robust characteristics of sliding mode control. The effectiveness of the proposed algorithm is demonstrated using simulation speed control of indirect field-oriented three-phase induction motor drives with regard to external load disturbances

DSP BASED IMPLEMENTATION OF FIELD ORIENTED CONTROL OF THREE-PHASE INDUCTION MOTOR DRIVES

The objective of this paper is to presents a practical implementation of field oriented control of three-phase induction motor based on Space Vector Pulse Width Modulation technique using Digital Signal Processing (DSP) board TMS320F2812. The control algorithm for the drive application is built with Code Composer Studio version 3.1. The motor control is divided into two control loops; inner current loop and outer speed control loop using PI controller. The rotor flux quantities are estimated using computational rotor time constant, rotor angular velocity and stator current. As a feedback of field oriented control, an incremental encoder is attached at the motor shaft and a Hall effect current sensor is used to detect the sent current to the motor. The performance of the drives system is tested under different speed command and load disturbance

Adaptive Sliding Mode For Indirect Field Oriented Controlled Of Induction Motor

In this paper, an adaptive Sliding Mode Control (SMC) for indirect field oriented control of three-phase induction motor is proposed. First, a sliding mode controller with integral sliding surface is designed. Then, an adaptive function of sliding gain is introduce to reduce the control effort of the SMC, so that there is no need to calculate the upper bound of the system uncertainties, as in traditional SMC. Finally the smooth function is applied to reduce chattering problem across the sliding surface. The speed control for the induction motor using the proposed control scheme is illustrated and the theoretical analysis for the adaptive SMC are described in detail. The results show that the proposed controller provides high performance characteristics and robust with regard to parameter variation and load disturbances. The effectiveness of the proposed scheme is verifying using MATLABISIMULINK

Sliding Mode Speed Control for Induction Motor Drives with State-Dependent Gain Method

The main obstacle of conventional sliding mode control is caused by discontinuous function of high control activity which is known as chattering phenomenon. In this research, the chattering phenomenon is significantly reduced by a newly developed algorithm. A fast sigmoid function with varying boundary layer algorithm is designed as a state-dependent to replace the discontinuous function in conventional sliding mode control. It is known that the switching gain of sliding mode control is proportional to the chattering level, and normally a large switching gain is applied to handle the uncertainties. This research proposes a state-dependent sliding mode control which is the switching gain and boundary layer is proportional to the sigmoid function of the sliding mode controller. As a result, the boundary layer and the switching gain will change depend on uncertainties of the motor drives system. The induction motor is controlled by vector control strategy, using indirect field orientation and Space Vector Pulse Width Modulation technique. Experimental result have proved that the proposed state-dependent sliding mode control able to deal with external load disturbances as well as effectively free from chattering phenomenon compared to conventional sliding mode control. The proposed algorithm and the vector control strategy are developed in digital signal processing board. The results have confirmed that the state-dependent sliding mode control is superior with regard to external load disturbances and variation in the reference speed setting when compared to conventional sliding mode control and fixed boundary layer sliding mode control

New Methodology for Chattering Suppression of Sliding Mode Control for Three-phase Induction Motor Drives

Chattering is undesirable phenomenon when dealing with sliding mode control. This paper proposed a new method for addressing chattering with a simple and easy implementation in Digital Signal Processor (DSP). This is realized by replacing the discontinuous function in conventional sliding mode control with statedependent auto-tuning of boundary layer in fast sigmoid function and state-dependent switching gain, for threephase induction motor speed control. This method allows chattering reduction in control input, while keeping the robustness characteristics of sliding mode control. The performance of the proposed control is verified in emulation induction motor drives using Digital Signal Processor TMS320F2812 board, with different speed command and load disturbances

Comparison Performance Of Indirect Field Oriented Control For Three-Phase Induction Motor Drive

This paper presents the comparative performances of Indirect Field Oriented Control (IFOC) for the three-phase induction motor. Recently, the interest of widely used the induction motor at industries because of reliability, ruggedness and almost free in maintenance. Thus, the IFOC scheme is employed to control the speed of induction motor. Therefore, P and PI controllers based on IFOC approach are analyzed at differences speed commands with no load condition. On the other hand, the PI controller is tuned based on Ziegler-Nichols method by using PSIM software which is user-friendly for simulations, design and analysis of motor drive, control loop and the power converter in power electronics studies. Subsequently, the simulated of P controller results are compared with the simulated of PI controller results at difference speed commands with no load condition. Finally, the simulated results of speed controllers are compared with the experimental results in order to explore the performances of speed responses by using IFOC scheme for three-phase induction motor drives