This thesis is in an attempt to realistically model a real-time digital generator which interfaces to an analog system simulator and which consists of the synchronous machine and its peripheral controllers such as the exciter and the governor-turbine subsystems. In this work, the exciter, the synchronous machine, the machine dynamics and the governor are modeled in detail while a simplified model of the turbine is used. The synchronous machine, the main component of this simulation, solves the discretized Park's machine equations which include flux derivative tenns and tenns pertaining to the two amortisseur windings. Treatment of saturation effects in the mutual inductances is also discussed. The Park's model is arranged to obtain a field voltage and machine armature cutTent input - machine tenninal voltage output structure, where the armature current and terminal voltage are rotor based quantities (i.e. in d-q domain). In order to interface the Park's machine model to the analog system model, the Park's and inverse Park's transformation are implemented by software modules. The implementation of a prototype model generator using a Motorola 68020 microprocessor and fast computer peripherals is discussed. The results of the digital computer simulation in real-time for the generator model under various operating conditions are presented. / Master of Science

Master of Science

No description available.

Generators in an interconnected power system normally remain in synchronism with one another. However, severe faults that lead to loss of heavily loaded generators or large load blocks can cause oscillations in the generator rotor angles that are large enough to result in a pole slip in which a generator, or a group of generators, loses synchronism with the rest of the power system. When a generator pole slips and falls out-of-step with the power system, the generator and system voltages sweep past one another at a slip frequency, producing a pulsating current, which can be greater than a three-phase fault at the generator terminals. An out-of-step generator should therefore be isolated from the power system to prevent damage to the generator, generator transformer and the turbine. This dissertation analyses the dynamic performance of generator-pole-slip protection during various stable and unstable power swing events. For the purpose of this dissertation, the Siemens 7UM622 machine protection relay is used to test the response of generator-pole-slip protection. This is done in two stages, firstly, within the DigSilent PowerFactory software by modelling the Siemens 7UM622 relay and then applying simulated time domain stable and unstable power swing conditions to the relay model to evaluate its response. Secondly, the actual 7UM622 hardware relay is injected with currents and voltages, which are produced during the time domain pole-slip simulations to determine if the relay hardware device operates in accordance with the Siemens relay technical manual. The power system analysed in the dissertation was heavily interconnected and a generator pole slip was rather unlikely. If an unlikely generator pole slip were to occur when the system is operating in a normal configuration (all power station outgoing feeders in service), the generator-pole-slip protection was able to detect and disconnect the generator after a single pole-slip cycle. v The critical fault clearing time decreases when an outgoing power station feeder is out of service (n-1 contingency) and therefore the probability of a generator pole slip increases. If a generator pole slip occurs when operating the network under a n-1 contingency, the pole-slip system electrical centre is usually located within the transmission network. In practice, the generator-pole-slip protection settings that are implemented at the power station do not reach into the transmission network (zone 2 disabled). Therefore, if a pole slip were to occur under a n-1 contingency, the generator-pole-slip protection would not be able to detect this condition. The zone 2 generator-pole-slip protection should rather reach into the transmission network, but the trip should only be issued after the third or fourth pole-slip cycle to allow the transmission line out-of-step protection sufficient time to separate the network into islands. The pole-slip function of the Siemens 7UM622 relay model within DigSilent PowerFactory operated in accordance with the Siemens relay technical manual and can be used in future to optimise and test generator-pole-slip protection settings. In the majority of cases, the Siemens 7UM622 relay hardware device operated in accordance with the Siemens relay technical manual. The only time that the relay operated incorrectly was when the measured impedance trajectory of a three-phase fault lingers on the inside and outside edge of the pole-slip impedance characteristic before exiting the pole-slip impedance characteristic. The stable and unstable power swing COMTRADE files that were generated for the tests performed in this dissertation can be used in future to test the generator-pole-slip protection at Kendal power station since it is rather difficult to test the pole-slip protection function properly without a COMTRADE file. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2013.

No description available.

Call number: LD2668 .T4 1984 D83 / Master of Science

by Lee Yin-sum. / Thesis (M.B.A.)--Chinese University of Hong Kong, 1981. / Bibliography: leaves 55-56.

Ching Ngai-hung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 81-83). / Abstracts in English and Chinese. / Chapter CHAPTER 1 ´ؤ --- INTRODUCTION --- p.1 / Chapter 1.1 --- Background on Micro Power Supply --- p.1 / Chapter 1.2 --- Literature Survey --- p.3 / Chapter 1.2.1 --- Comparison Among Different Power Sources & Transduction Mechanisms --- p.3 / Chapter 1.2.2 --- Previous Works in Vibration Based Generator --- p.6 / Chapter CHAPTER 2 一 --- DESIGN OF THE MICRO-POWER GENERATOR --- p.8 / Chapter 2.1 --- Concept of Power Generation --- p.8 / Chapter 2.2 --- Design Objectives of the Micro Power Generation --- p.9 / Chapter 2.3 --- System Modelling and Configuration of the Generator --- p.10 / Chapter 2.4 --- RESONATING STRUCTURE --- p.13 / Chapter 2.4.1 --- Material Selection --- p.13 / Chapter 2.4.2 --- Fabrication Method --- p.14 / Chapter CHAPTER 3 一 --- INDUCTING STRUCTURE --- p.17 / Chapter 3.1 --- Selection of Winding Method --- p.17 / Chapter 3.2 --- Solenoid Windings --- p.19 / Chapter 3.2.1 --- Fabrication Process --- p.19 / Chapter 3.3 --- PCB Windings --- p.20 / Chapter 3.3.1 --- Fabrication Process of the Prototype of Six-layer PCB --- p.21 / Chapter CHAPTER 4 一 --- EXPERIMENTAL RESULTS --- p.27 / Chapter 4.1 --- Experimental Setup --- p.27 / Chapter 4.1.1 --- Generator Systems --- p.27 / Chapter 4.1.2 --- Measurement of Vibration and Output from the Generator --- p.28 / Chapter 4.1.3 --- Observations of Vibration Motions --- p.31 / Chapter 4.2 --- SPRING FOR THE MICRO GENERATOR --- p.32 / Chapter 4.2.1 --- Spring Micromachining Optimization --- p.32 / Chapter 4.2.2 --- Mode Shapes and Spiral-spring Structures --- p.35 / Chapter 4.3 --- MAGNET FOR THE MICRO GENEARTOR --- p.37 / Chapter 4.3.1 --- Generator Output and Magnetic Dipole Orientation --- p.37 / Chapter 4.4 --- HAND-WIRED COIL GENEARTOR --- p.45 / Chapter 4.4.1 --- Performance of Different Design of Housings --- p.45 / Chapter 4.5 --- PCB COIL GENERATOR --- p.48 / Chapter 4.5.1 --- Size of PCB Coils vs. Generator Output --- p.48 / Chapter 4.5.2 --- Effect of Number of PCB Layers --- p.54 / Chapter 4.5.3 --- Array of Generators --- p.61 / Chapter CHAPTER 5 一 --- MODELLING AND COMPUTER SIMULATION --- p.63 / Chapter 5.1 --- Modelling the Second-Order System --- p.63 / Chapter CHAPTER 6 一 --- APPLICATION DEMONSTRATIONS --- p.69 / Chapter 6.1 --- INFRARED SIGNAL TRANSMISSION --- p.69 / Chapter 6.2 --- RF WIRELESS TEMPERATURE SENSING SYSTEM --- p.70 / Chapter CHAPTER 7 ´ؤ --- CONCLUSION --- p.75 / Chapter CHAPTER 8 一 --- FUTURE WORK --- p.77 / BIBLIOGRAPHY --- p.81 / APPENDIX --- p.84

This thesis presents a study on the design method to optimise the performance for producing green power from multiple renewable energy generators. The design method is presented through PLC (Programmable Logic Controller) theory. All the digital and analogue inputs are connected to the input cards. According to different operations conditions for each generator, the PLC will image all the inputs and outputs, from these images; a software program has been built to create a control method for multiple renewable energy generators to optimise production of green power. A control voltage will supply the output contractor from each generator via an interface relay. Three renewable generators (wind, solar, battery bank) have been used in the model system and the fourth generator is the back up diesel generator. The priority is for the wind generator due to availability of wind 24 hours a day, then solar, battery bank, and LPG or Diesel generators. Interlocking between the operations of the four contractors has been built to prevent interface between them. Change over between contractors, according to the generator's change over has also been built, so that it will delay supplying the main bus bar to prevent sudden supply to the load. Further study for controlling multiple renewable energy generators for different conditions such as controlling the multi-renewable energy generators from remote, or supplying weather forecast data from bureau of meteorology to the PLC directly as recommended. / Master of Electrical Engineering (Hons)

Thesis (M.S.)--University of Nevada, Reno, 2005. / "August 2005." Includes bibliographical references (leaves 118-127). Online version available on the World Wide Web.