Muhammad H. Rashid

Speed nonlinear control of DC motor drive with field weakening

In this paper, we show that it is feasible to apply nonlinear MIMO feedback linearization technique to a separately excited DC motor system that is operated in high-speed field-weakening regime. Load-adaptive and sensorless control techniques to improve dynamic speed performance are proposed and compared. Also, application results are presented to verify theoretical ones.

High performance nonlinear MIMO field weakening controller of a separately excited dc motor

Abstract This paper presents a novel technique for field weakening implementation of separately excited dc motors. A constant power field weakening controller, which is based on nonlinear load adaptive multi-input multi-output (MIMO) linearization technique, is proposed and developed for achieving speed tracking. Due to the effects of decoupling and linearization, it allows the controller to be implemented and operated at any desired field weakening point of operation. To demonstrate the effectiveness of the proposed controller, the results of computer simulations are presented for a specific motor. The performance of this proposed controller is compared with that of the traditional linear PI controllers. The results show that the proposed controller provides the globally higher speed control performance, while the motor is operated over a wide dynamic regime of field weakening, even under the presence of load torque disturbance.

QFT-based robust and precision motion control system for a high speed direct-drive XY table positioning mechanism

In this paper, a new quantitative feedback theory (QFT) based robust and precision control system is proposed for a high speed direct-drive XY-table positioning mechanism in semiconductor wire-bonding applications. The most difficult control problems of the systems, caused by mechanical resonances, are solved by the use of a robust velocity feedback controller in the inner loop of the cascaded control structure. The resulting velocity controller and the outer loop position controller are used in combination with auto-tuning feedforward controller to assure consistent and high tracking performance of the motion system with good stability, robustness, disturbance rejection and sensor noise suppression. Validation and implementation of the motion profile with a maximum acceleration of 6.8 g (1g=9.81 m/s/sup 2/) are carried out on tens of mass produced wire-bonding machines in order to confirm the effectiveness of the control strategy.

Switched capacitor four-quadrant DC/DC Luo-converter

Classical DC/DC converters usually consist of inductors and capacitors such as buck converter, boost converter, buck-boost converter, Luo-converters and Cuk-converter. All classical converter has big size and low power density. Switched-capacitors have been successfully employed in the inductorless DC/DC converters and opened the way to build the converters with high power density. However, most of these converters in the literature perform in single-quadrant operation. Some of them work in the push-pull status, and their control circuit and topologies are very complex. This paper introduces a switched capacitor four-quadrant DC/DC Luo-converter. The experimental results verified our analysis and calculation.

Simulation of Power Electronic Circuits

This section introduces the needs and problems of simulating power electronics circuits. It describes various simulating techniques. Also included are the features of the SPICE software package and illustrations by example of the simulation of a number of power electronic circuits.

Nonlinear Load-Adaptive MIMO Controller for DC Motor Field Weakening

Control problem of field weakening for a separately excited DC motor system, modeled in nonlinear differential equations, is tackled in this paper. A novel constant power field weakening controller, based on nonlinear load-adaptive multi-input multi-output (MIMO) linearization technique, is developed to achieve high-performance speed tracking through rejecting load disturbance. The effects of decoupling and linearization permit the controller to be implemented and operated at desired field weakening point of operation. Computer simulations are presented to demonstrate the effectiveness of the proposed controller for a specific motor. It has been shown that the proposed controller provides higher dynamic performance in comparison with traditional PI controllers, whereas the motor system is run over wide dynamic field weakening regimes.Control problem of field weakening for a separately excited DC motor system, modeled in nonlinear differential equations, is tackled in this paper. A novel constant power field weakening controller, based on nonlinear load-adaptive multi-input multi-output (MIMO) linearization technique, is developed to achieve high-performance speed tracking through rejecting load disturbance. The effects of decoupling and linearization permit the controller to be implemented and operated at desired field weakening point of operation. Computer simulations are presented to demonstrate the effectiveness of the proposed controller for a specific motor. It has been shown that the proposed controller provides higher dynamic performance in comparison with traditional PI controllers, whereas the motor system is run over wide dynamic field weakening regimes.

Nonlinear load-adaptive MIMO controller for high performance DC motor field weakening

A separately excited DC motor system is modeled by highly nonlinear and coupled differential equations in the field weakening region. A novel constant power field weakening controller, which is based on nonlinear load-adaptive multi-input multi-output linearization, is presented. Due to the effects of coupling and linearization, the controller achieves sized tracking at and desired set point of operation. The results of computer simulation are presented to demonstrate the controllers effectiveness for a representative motor. The performance of this controller is compared with that of the traditional linear PI controllers. It has been shown that the proposed controller provides the globally higher speed control performance, while the motor is operated over a wide dynamic regime of field weakening, even under the presence of load torque disturbance.

Adaptive MIMO Backstepping Controller for High-Performance DC Motor Field Weakening

A novel field-weakening technique has been investigated for separately excited DC motor systems that exhibit considerable nonlinearities. Based on proper selection of a Lyapunov function, an adaptive multi-input multi-output backstepping field-weakening control law has been derived for speed tracking. Because of the decoupling effect, this controller achieves speed tracking at any desired set point of operation. Computer tests are carried out for a specific motor to demonstrate the effectiveness of the proposed controller. It has been shown that the controller provides the globally robust speed control performance, while the motor system is operated over a wide dynamic regime of field weakening, even under the presence of uncertainties in both parameters and load torque.

Nonlinear MIMO Speed Sensorless Controller for DC Motor Field Weakening

This paper addresses speed control of a separately excited DC motor (SEDCM) in nonlinear field weakening region. Input output linearization (IOL) technique is used to deal with the motor system with considerable nonlinearity, and a nonlinear multi-input multi-output (MIMO) speed tracking controller is developed for constant power field weakening. The effects of decoupling and linearization permit the controller to be implemented and operated at any desired field weakening point of operation. The control scheme combining this controller with nonlinear speed/load torque observer is, in particular, proposed for speed sensorless operation. Computer simulations are presented to show speed tracking performance of the proposed overall scheme.This paper addresses speed control of a separately excited DC motor (SEDCM) in nonlinear field weakening region. Input output linearization (IOL) technique is used to deal with the motor system with considerable nonlinearity, and a nonlinear multi-input multi-output (MIMO) speed tracking controller is developed for constant power field weakening. The effects of decoupling and linearization permit the controller to be implemented and operated at any desired field weakening point of operation. The control scheme combining this controller with nonlinear speed/load torque observer is, in particular, proposed for speed sensorless operation. Computer simulations are presented to show speed tracking performance of the proposed overall scheme.

Applications and market analysis of DC-DC converters

This paper investigates the basic principles of operation of DC-DC converters and their applications. A market analysis was performed. This work was performed to determine the significance of DC-DC converters on the power electronic market. Research was further performed to focus on how buck-boost converters are used in everyday life along with their benefits and shortcomings when designed.