The vector control signal processing blockset for use with Matlab and Simulink

This paper describes the newly developed Vector Control Signal Processing (VCSP) blockset for use with Matlab(R) and Simulink(R). The originality of this blockset consists of the extension of Simulink for design, simulation and prototyping of signal processing algorithms in motion control systems. This blockset is the first know collection of Simulink blocks to bridge the gap between digital algorithm development and subsequent implementation in motion control systems. The VCSP blockset together with Real-Time Workshop uses the inherent visual programming techniques of Simulink and a number of pre-built blocks to reach the above goals. Due to its open and flexible nature this approach is also very useful as a tool for teaching. This paper is focused on modelling and simulation of motion control systems, in particular employing rotating AC machines and vector control methods. The basic blockset functions and some examples of modelling techniques for simple drive and complex drive structures are presented. Simulations results are also presented and discusse

Sinteza backstepping regulatora za praćenje maksimalne proizvodnje energije u fotonaponskim sustavima

This work presents a new control method to track the maximum power point of a grid-connected photovoltaic (PV) system. A backstepping controller is designed to be applied to a buck-boost DC-DC converter in order to achieve an optimal PV array output voltage. This nonlinear control is based on Lyapunov functions assuring the local stability of the system. Control reference voltages are initially estimated by a regression plane, avoiding local maximum and adjusted with a modified perturb and observe method (P&O). Thus, the maximum power extraction of the generating system is guaranteed. Finally, a DC-AC converter is controlled to supply AC current in the point of common coupling (PCC) of the electrical network. The performance of the developed system has been analyzed by means a simulation platform in Matlab/Simulink helped by SymPowerSystem Blockset. Results testify the validity of the designed control method.Ovaj rad predstavlja novu metodu upravljanja za slije.enje točke maksimalne snage fotonaponskog (PV) sustava. Dana je sinteza backstepping regulatora za primjenu u silazno-uzlaznom DC-DC pretvaraču za postizanje optimalnog izlaznog napona PV-a. Ova je nelinearna metoda upravljanja zasnovana na Ljapunovim funkcijama osiguravajući tako lokalnu stabilnost sustava. Upravljačke reference napona prvo su estimirane korištenjem regresijske ravnine izbjegavajući lokalne maksimume, a zatim podešene tzv. modificiranom perturbiraj i uoči metodom (P&O). Prema tome, zagarantirano je maksimalno izvlačenje energije iz sustava proizvodnje. Naposlijetku, DC-AC pretvaračem upravlja se na način da osigurava željena izmjenična struja u točki zajedničkog spoja (PCC) elektroenergetske mreže. Ponašanje razvijenog sustava analizirano je kroz simulacije provedene u Matlab/Simulink okruženju uz korištenje SymPowerSystem biblioteke

AUTOMATED GUIDED ROBOT (AGR)

This project concerns the design and fabrication of the Automated Guided Robot (AGR) prototype, utilizing artificial intelligence (AI) and genetic algorithm (GA) as a mainframe in helping the robot to generate a self-understanding of the area of work and mobilization to a destination desired by the user. The main objective of this project is to create and develop a Path Planning Mobile Robot able to avoid obstacles in its path and reach a target designated position from its starting point utilizing 3 wheel-based rover body, sensors, linear motors and microcontrollers. Compared to manual mobile robots, AGRs require sensors and control systems that generate feedback for the re-evaluation of an unexpected situation and to detect obstacles in the path the AGR is required to follow. The paper describes the network algorithms developed and used in the design process of the AGR including simulations and circuit designs done for the prototype. A general robotics circuit construction of the mainframe target board for central processing, a controller board for the sensor feedbacks and a small base tri-wheeled structure has been fabricated by the author and continual troubleshooting and enhancement has been done for these components of the AGR. Algorithm conversion to C code programming has been done throughout the project for the obstacle avoidance and path planning algorithms based upon the GA platform ofAI

Simulation of Offshore Wind System with Three-Level Converters: HVDC Power Transmission in Cloud Scope

This paper is on a simulation for offshore wind systems in deep water under cloud scope. The system is equipped with a permanent magnet synchronous generator and a full-power three-level converter, converting the electric energy at variable frequency in one at constant frequency. The control strategies for the three-level are based on proportional integral controllers. The electric energy is injected through a HVDC transmission submarine cable into the grid. The drive train is modeled by a three-mass model taking into account the resistant stiffness torque, structure and tower in the deep water due to the moving surface elevation. Conclusions are taken on the influence of the moving surface on the energy conversion

Adaptive digital predistortion for power amplifier linearization

Ankara : The Department of Electrical and electronics Engineering and the Institute of Engineering and Science of Bilkent University, 2008.Thesis (Master's) -- Bilkent University, 2008.Includes bibliographical references leaves 75-77.High power amplification of linear modulation schemes which exhibit fluctuating envelopes, invariably leads to the generation of distortion and intermodulation products. In order to avoid these effects, maintaining both power and spectral efficiency, it is necessary to use linearization techniques. By using linearization techniques, the amplifier can be operated near the saturation with good efficiency and linearity. The technique proposed here is predistortion based on a look-up table (LUT) method using input and output signal envelopes. The predistortion is implemented using a LUT and an address generation block that selects the appropriate coefficient from the LUT, given the magnitude of the input signal. The testing of the predistorter is done by using a baseband system model which consists of a 16-QAM modulator, an upsampler, a raised cosine filter, the predistorter and a baseband behavioural amplifier model. The performance of the predistorter with a new LUT update method is evaluated in terms of power efficiency and spectrum efficiency. MATLAB simulations show that to obtain up to 25-30 dB improvement in power spectrum is possible and sufficiently large LUT size is needed to reduce the background noise level. Furthermore, the performance of the predistorter in the case of an amplifier with memory is also investigated. The algorithms have been implemented on an FPGA chip. The performance of the system is as predicted in MATLAB simulations.Aslan, Makbule PehlivanM.S

Frequency-domain method for measuring alpha factor by self-mixing interferometry

Linewidth enhancement factor, also known as the alpha factor, is a fundamental characteristic parameter of a laser diode (LD). It characterises the broadening of the laser linewidth, the frequency chirp, the injection lock range and the response to external optical feedback. In the past few decades, extensive researches have been dedicated to the measurement of alpha. Among all the existing approaches, the methods based on selfmixing interferometry (SMI) are considered the most simple and effective. The core components of a SMI consist of an LD, a lens and a moving target. When a portion of laser light backscattered or reflected by the external target and re-enters the laser cavity, a modulated lasing field will be generated. The modulated laser power is also called SMI signal, which carries the information of target movement and LD related parameters, including alpha

THE NUMERICAL CALCULATION OF LOW FREQUENCY ELECTROMAGNETIC TRANSIENT PHENOMENA IN POWER TRANSFORMERS

U radu je predstavljen model transformatora primjenjiv u niskofrekvencijskim elektromagnetskim prijelaznim pojavama, frekvencija reda oko 1 kHz. Analiziran je primjer uklapanja neopterećenog energetskog transformatora. Prvo je pokazan pojednostavljeni analitički pristup, a zatim, zbog njegova ograničenja, u analizu je uveden numerički pristup rješavanja krutih diferencijalnih jednadžbi koje opisuju prijelaznu pojavu. U oba slučaja je realiziran algoritam za generiranje valnih oblika varijabli stanja. Rezultati oba algoritma su uspoređeni s rezultatima MATLAB/Simulink/Power System Blockset, namjenskog programa za analizu elektromagnetskih prijelaznih pojava u elektroenergetskom sustavu. Razvijeni algoritam se može uspješno koristiti u ostalim niskofrekvencijskim prijelaznim pojavama gdje je glavni predmet analize nelinearni karakter transformatora: ferorezonancija, ispad tereta, kvarovi kod transformatora itd. Na kraju su pokazane usporedbe mjerenih i simuliranih struja uklapanja trofaznog trostupnog transformatora.In this article, a transformer model is presented that is applicable to low frequency electromagnetic transient phenomena of up to 1 kHz. An example of the energization of a no-load transformer is analyzed. A simplified analytical approach is presented first. Due to the limitations of this approach, a numerical approach is introduced for the solution of the stiff differential equations that describe the transient phenomena. In both cases, algorithms have been developed for generating the waveforms of the state variables. The results of both algorithms are compared to the results of the MATLAB/Simulink/Power System Blockset for the analysis of electromagnetic transient phenomena in electrical energy systems. Developed algorithm with the introduced numerical approach can be used successfully in other low frequency transient phenomena where the main subject of analysis is the nonlinear character of the transformer: ferroresonance, load switch-off, transformer faults etc. Finally, a comparison is made between the measured and simulated inrush currents of a three-phase three-legged transformer

Control strategy for selective compensation of power quality problems through three-phase four-wire UPQC

This paper presents a novel control strategy for selective compensation of power quality (PQ) problems, depending upon the limited rating of voltage source inverters (VSIs), through a unified power quality conditioner (UPQC) in a three-phase four-wire distribution system. The UPQC is realized by the integration of series and shunt active power filters (APFs) sharing a common dc bus capacitor. The shunt APF is realized using a three-phase, four-leg voltage source inverter (VSI), while a three-leg VSI is employed for the series APF of the three-phase four-wire UPQC. The proposed control scheme for the shunt APF, decomposes the load current into harmonic components generated by consumer and distorted utility. In addition to this, the positive and negative sequence fundamental frequency active components, the reactive components and harmonic components of load currents are decomposed in synchronous reference frame (SRF). The control scheme of the shunt APF performs with priority based schemes, which respects the limited rating of the VSI. For voltage harmonic mitigation, a control scheme based on SRF theory is employed for the series APF of the UPQC. The performance of the proposed control scheme of the UPQC is validated through simulations using MATLAB software with its Simulink and Power System Block set toolboxes