Power
Permanent URI for this collectionhttps://dspace.univ-boumerdes.dz/handle/123456789/3079
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Item Reliability assessement using a novel algorithm(2016) Khelifa, Salah Eddine; Houassine, Mouloud Massinissa; Bourezg, Abderrabi (supervisor)This work deals with design and implementation of a novel algorithm for path tracing method. It was developed to perform reliability analysis for a wide class of systems using reliability block diagrams. The application can sort the weakness elements of the system and improve their reliabilities using redundancy concept. The contribution of this project is based on an extension of the probability union theorem which is used in computing system’s reliability and helps to solve the computational time complexity problem. The RBD is modeled using the directed acyclic graphs. The input to the algorithm is the adjacency matrix, mission time, and components failure rates. Given a starting node and ending node of RBD, the algorithm searches for all available paths between these two nodes, then, evaluates the reliability of each path as series combination and transforms it using inclusion exclusion principle to output the system’s reliability expression, the application is tested on pilot protection transmission line using Permissive Overreaching Transfer Trip (POTT) scheme supported with microwave communication channel.Item Simulink /modelsimco-simulation of direct torque control for induction motors(2016) Benyoucef, Imad Eddine; Ghoualmi, Mohcene; Metidji, B. (Supervisor)This project presents a generic model of a direct torque controller (DTC) for induction machines (IMs) using field programmable gate array (FPGA). The DTC performance is significantly improved by the use of FPGA, which can execute the DTC algorithm at higher sampling frequency. This model is developed in order to reduce the sampling period to a point where torque ripple is minimal, while maintaining the classical DTC control structure. To get simpler implementation and fast computation, minimizing calculation errors and consuming hardware resource usage, three methods were introduced: i) two´s complement fixed-point format and a variable word-size approach was followed, ii) the modified non-restoring method to calculate complicated square root operation of stator flux and iii) a new sector analysis method. The design of the FPGA-based DTC for IMs is presented. Firstly, a novel DTC architecture was designed. Secondly, very-high-speed integrated circuit hardware description language (VHDL) is adopted to describe the behavior of the control algorithms. Finally, to evaluate the effectiveness and correctness of the proposed DTC, a co-simulation work performed by Matlab/Simulink and Modelsim is conducted. The simulation results will be discussed.Item Improving the efficientcy of photovoltaic power systems(2016) Bouznada, Khaled; Obeidi, Baha Eddine; Boutora, S.With the increase of the world’s population day by day, the demand of energy is increasing accordingly. Although oil and gas are the main energy resource in the world currently, experts say that this wouldn’t be the case in the next decades. The focus on renewable energies has increased and it gained the attention of nations around the globe. Solar energy and exactly photovoltaic (PV) systems are considered as one of the main energy resources especially in warm countries. One challenge is to have systems that operate with high efficiency. Our thesis reviews different methods to increase their efficiency. The main methods, which are, solar tracking, maximum power point tracking and cell cooling; are detailed and simulated using simulation dedicated software. Results show the significant improvement in PV systems efficiency when applying these methods.Item EPGA based control of single phase SVC(2016) Kamel, Tayeb Djamel Eddine; Boudjouraf, Walid; Kheldoun, AissaPower quality is one of the most important indicator in electrical engineering. Variations in the impedance should be noticed for any external disturbance or change in the parameters of the electrical systems. These variation affect the reactive power hence the power factor. The use of capacitors and inductors is the classical method to compensate the reactive power but still slow to operate and decreases the power quality. Flexible AC transmission systems (FACTS) are compensators that uses a control unit and power electronic switches to vary the impedance of the systems. The idea of this work is to change the switching and the control method of the static VAr compensator (SVC). Classical SVCs are based on thyristors for switching and using a simple control unit. Our method is to change the control unit by using an FPGA and a bidirectional switch to enhance the power quality and increase the speed of switching.Item PC based relay tester(2016) Mazouz, Alaa Eddine; Messauodi, Mohamed; Bentarzi, Hamid (Supervisor)Power quality disturbances are an issue that is gaining so much attention within the research community because of its detrimental consequences on the power grid, instruments and customers alike. Relays are the first line of defense in the face of these disturbances rendering their existence the most important in the protection scheme; relay testing is therefore just as important. This project deals with the design and implementation of a Relay Tester, which is based on the simulation of power quality disturbances and fault signals using LabVIEW environment and the generation of these signals using data acquisition card. These fault signals are amplified to the standard relay values using a Class-D amplifier. The amplified signals are injected into the relay to test its functionality.Item Mitigating ferroresonance in MV power system involving power transformer and circuit breaker capacitance using alternating transient program(2016) Bedda, Zekri Sad; Mekkaoui, Tarek; Boutora, S. (Supervisor)Ferroresonance is a phenomenon usually initiated by transients in power networks resulting from switching operations or ground faults or others. Nonlinear behavior of the core of a power transformer results in magnetic saturation. Long-lasting ferroresonant state is dangerous to the equipment due to prolonged overvoltage and large overcurrents in MV windings. In this thesis, a ferroresonance solution using Alternating Transient Program, was attempted. The ferroresonant oscillations analyzed result from interaction between the power transformer and a grading capacitance of a circuit breaker. Some practical solutions are suggested and introduced after creating a ferroresonance situation, they had a considerable effect on damping and eliminating the risk of ferroresonance.Item Mppt, Yaw and pitch angle control of variable speed wind turbine(Université M’Hamed BOUGARA de Boumerdes : Institut de génie electrique et electronique (IGEE), 2016) Teddar, Oussama; Mesroub, Hicham Eddine; Bourezg, , Abderrabi (Supervisor)The aim of the work presented in this project is to evaluate how different strategies of controlling a variable speed wind turbine using MPPT control (power, torque and speed control) Yaw control and pitch angle control and how this control affect the efficiency and performance of the wind turbine system. The simulation tests have been done using MATLAB /SIMULINK software under different wind speed condition, generator control take place when the wind speed is low or below rated speed to maintain the MPPT, where the pitch control intervene when wind speed is beyond rated value to limit generated power, the turbine should stop at The cutoff wind speed due to the potential damage. Variable-speed systems can increase the production of the energy, PMSG generator is connected to the grid through a power converter to rectify and thereafter invert the voltage to a desired grid frequency.Item Photovoltaic emulator(Université M’Hamed BOUGARA de Boumerdes : Institut de génie electrique et electronique (IGEE), 2016) Reffafa, Abderrahmane; Derradji, Houssam Eddine; Chafai, Mahfoud (Supervisor)This work is concerned with the design and implementation of photovoltaic source emulator, which is a power converter whose output voltage and current are controllable so that to reproduce the electrical behavior of a photovoltaic panel. This is achieved through a simulation environment based on a Matlab algorithm that receives the photovoltaic panel parameters, the applied irradiance and temperature, and then calculates the corresponding I-V curve and operating point. These are transferred to the hardware through a microcontroller. Finally the hardware generates the desired Voltage and current, which emulate the output of the real PV panel.Item FPGA Based Control of Three Level NPC Inverter(Université M’Hamed BOUGARA de Boumerdes : Institut de génie electrique et electronique (IGEE), 2016) Khenfer, Zoubir; METIDJI, B. (supervisor)Power electronics is the technology associated with efficient conversion, control and conditioning of electric power from its available input in to the desired electrical output form. The actual work falls into this scope presenting an FPGA based control and implementation of three levels voltage NPC inverter. The Multi-Carrier Sinusoidal Pulse Width Modulation (MC-SPWM) is the control method adopted in order to digitize power so that a sequence of voltage pulses can be generated by the on and off of the power switches. writing a VHDL code of the adopted modulation technique ,checking the code on MODELSIM software then loading the code to the FPGA kit through QUARTUS environment are the carried steps in order to end up with the right switching signals. The design and implementation of the appropriate gate drive circuitry is a the next step in order to assure a suitable driving circuit that is required to supply the necessary charge to the power valves gates . Using this control method and the gate driving circuitry along with the specified topology of the three levels NPC inverter leads to the desired results of this works. Results that are presented and discussed.Item Design and implementation of different types of grounding system(Université M’Hamed BOUGARA de Boumerdes : Institut de génie electrique et electronique (IGEE), 2016) Tebbal, Mouadh Salah Eddine; Rimane, Abdennacer; Bentarzi, Hamid (Supervisor)There is no doubt that safety is major concern of technology and development, because a system that is badly secured may put the human life on stake, moreoverthe non-safe installations reflect also on the economic cost as well as the energy loss, where according to statistics about 75% of electricity losses are due to faults on distribution networks, so it is essential to provide suitable protection schemes and relay selection to ensure the fastest disconnection of faulty parts in order to minimize outage times and thus improving the continuity of power supply. As one could not cover all safety systems, our concern is focused only on grounding methods and their protection techniques; we have discussed the different grounding types with advantages, disadvantages and applications of each. The main types are being discussed in this report are: TT, TN-C and IT systems each one has a special design and characteristic that differs from the others. Also the protection devices have discussed briefly showing the most important ones with their applications. The simulation has been performed for the three grounding systems stated previously and the test of tripping of the differential and electromagnetic thermal relay in each type. Finally the three systems have been implemented and tested to show their behaviors under different conditions such a phase to ground fault (load is short circuited).