Dariusz L. Sobczuk

Active filtering function of three-phase PWM boost rectifier under different line voltage conditions

Slight hardware and algorithm modifications as well as a higher power ratio of a three-phase pulsewidth-modulation (PWM) rectifier make compensation of neighboring nonlinear power load possible. The active filtering function enlarges the functionality of PWM rectifiers, which decreases the cost of additional installation of compensating equipment. It gives a chance to fulfill both shunt active filter (SAF) and PWM rectifier tasks in a multidrive system by one advanced converter. Thanks to the idea of virtual flux, the direct power control space-vector-modulated (DPC-SVM) and new synchronous double reference frame phase-locked loop approach, the control system is resistant to a majority of line voltage disturbances. This assures proper operation of the system for abnormal and failure grid conditions. Simulation and experimental results have proven excellent performance and verify the validity of the proposed system.

Simplified stator flux oriented control

In the paper, a simple vector control scheme for PWM inverter-fed induction motors is described. The principle of the operation is based on the idea of natural field orientation (NFO). Theoretical basis and implementation as well as some simulated and experimental results illustrated the dynamic and static performances of the drive are presented. Some improvements by using closed torque and flux control loops are proposed.

DSP implementation of neural network speed estimator for inverter fed induction motor

The paper presents the application of online trained neural networks (NN) working as speed estimators for the speed control of induction motors. Improvement of the basic scheme using small structure modification is shown. Also, a new method of speed estimation is described. The implementation of the both systems based on the TMS320C31 is presented. Experimental and simulation results are also shown.

Feedback Linearization Control of Inverter Fed Induction Motor - with Sliding Mode Speed and Flux Observers

This paper presents a feedback linearization approach for high performance induction motor control. Some oscillograms illustrating the properties of the PWM inverter-fed induction motor with control via feedback linearization are presented. The sliding mode observer is used to estimate the rotor flux and the angular speed of the motor

Improved neural network current regulator for VS-PWM inverters

In the paper the application of an off-line trained neural network (NN) working as a current regulator for a three phase PWM inverter is presented. It is shown that this type of NN regulator has operation characteristics similar to delta modulators which cannot apply the zero voltage vector. When the NN output signals are sampled not at the same instant but with a phase shift, i.e. 2/spl pi//3, the regulator can select zero vectors and always chooses adjacent active vectors. This guarantees the lower RMS error for the same mean switching frequency. Finally, two different learning techniques for such current regulators are discussed and compared.<<ETX>>

Remote experiment system and internet based teaching of PWM techniques for three-phase voltage source converters

The paper details a successful of a remote laboratory and internet based teaching of PWM techniques for three-phase voltage source converters. The first stage of exercises is based on developed java applets for interactive simulation of carrier based PWM (CB-PWM) and space vector based modulation (SVM) techniques. The physical experiment is based on a three-phase IGBT bridge converter with DSP control and modulation. Signal measurements and processing are implemented in LabView environment. The master control and experiment web pages are governed by Moodle Course Management system, which provides access restrictions by means of a booking system. The presented PWM module is a part of Power Electronics and Drives course developed within the project EDIPE supported by European Commission - Leonardo da Vinci II Programme.

Distant learning of pulse width modulation techniques for voltage source converters

Paper presents distant learning of PWM techniques using java applets and remotely controlled and monitored experimental setup. The scope of presented material as well as exercises details are discussed. Moreover, the topology and components of the experimental setup are also presented.

Some Aspects of Nonlinear and Discontinuous Control with Induction Motor Applications

In this Chapter the theory of nonlinear control systems is shortly described. The nonlinear feedback linearization control (FLC) and discontinues sliding mode control (SMC) are presented. Moreover, several applications of nonlinear control methods for induction motor drive are shown. The FLC guarantees the exactly decoupling of the motor speed and rotor flux control. Thus this control method gives a possibility to get very good behavior in both dynamic and steady states. The SMC approach assures direct control of inverter legs and allows using a simple table instead of performing complicated PWM calculation. Moreover the SMC is robust to drive uncertainties. The good behaviour of rotor flux and mechanical speed Sliding Mode Observers (SMO) is the important feature of the system. Therefore, presented approaches are very useful in a variety of applications and, in particular, in the drive systems and power electronics.

Internet Based Teaching of Pulse Width Modulation for Three-Level Converters

In the paper a Internet based teaching of Pulse Width Modulation (PWM) methods for three-level inverters is presented. In the first part the basic methods of PWM modulation are discussed. In the second part selected applets for individual teaching of PWM methods will be briefly described.

Selected Problems of Discontinues Control of Inverter Fed Induction Motor Drives

In this Chapter a combined discontinues sliding mode control (SMC) with feedback linearization control (FLC) applied for voltage source inverter-fed induction motor are presented. The FLC guarantees the exactly decoupling of the motor speed and rotor flux control. Thus this control method gives a possibility to get very good behavior in both dynamic and steady states. The SMC approach assures direct control of inverter legs and allows using a simple table instead of performing PWM online calculation. Moreover, the SMC is robust to drive uncertainties. The good behaviour of rotor flux and mechanical speed Sliding Mode Observers (SMO) is the important feature of the system. Therefore, the presented approaches are very useful in a variety of applications and, in particular, in drive systems, robotics and power electronics.