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Full-Text Articles in Engineering

Novel Control And Harmonics Impact Of Pv Solar Farms, Byomakesh Das Dec 2012

Novel Control And Harmonics Impact Of Pv Solar Farms, Byomakesh Das

Electronic Thesis and Dissertation Repository

This thesis presents a novel application of Photovoltaic (PV) solar system inverter, both during night and day, as a dynamic reactive power compensator STATCOM. This technology, termed PV-STATCOM, is designed and developed for power factor correction in the networks of two utilities: Bluewater Power, Sarnia, and London Hydro. This thesis further describes for the first time, the harmonic impact studies on a utility distribution network in presence of the largest PV solar farm in Canada.

This novel utilization of a PV-STATCOM for power factor correction of induction motor loads is demonstrated with (i) electromagnetic transient simulation in EMTDC/PSCAD software, (ii) …


Protection And Control Of Active Distribution Networks And Microgrids, Mohammad Amin Zamani Nov 2012

Protection And Control Of Active Distribution Networks And Microgrids, Mohammad Amin Zamani

Electronic Thesis and Dissertation Repository

This thesis is mainly focused on (i) modeling and control of Electronically Coupled Distributed Energy Resources (EC-DERs) under severe network imbalances and transient incidents, and (ii) protection of active distribution networks and microgrids against different types of faults. In the first part, an enhanced control strategy is proposed to improve the performance of EC-DERs under faults and transient disturbances, in a multi-unit microgrid setting. With the use of proposed control strategy, the host microgrid can ride through network faults, irrespective of whether they take place within the microgrid jurisdiction or impact the upstream grid, and quickly reclaim its pre-fault operating …


Modelling Of The Western University Campus Electrical Network For Infrastructural Interdependencies In A Disaster Response Network Enables Platform, Gagandeep S. Gill Nov 2012

Modelling Of The Western University Campus Electrical Network For Infrastructural Interdependencies In A Disaster Response Network Enables Platform, Gagandeep S. Gill

Electronic Thesis and Dissertation Repository

The interdependencies that exist between multiple infrastructures can cause unexpected system behaviour when their component failure occurs due to large disruptions such as earthquake or Tsunami. The complexities of these interdependencies make it very difficult to effectively recover infrastructure because of the several challenges encountered. To overcome these challenges, a research program called Disaster Response Network Enabled Platform (DR-NEP) was initiated. This thesis deals with the modelling of electrical networks in order to study critical infrastructures interdependencies as a part of DR-NEP project. In first module of the thesis, the concept and understanding of interdependencies is presented. For studying the …


Novel Controls Of Photovoltaic (Pv) Solar Farms, Shah Arifur Rahman Oct 2012

Novel Controls Of Photovoltaic (Pv) Solar Farms, Shah Arifur Rahman

Electronic Thesis and Dissertation Repository

Solar Farms are absolutely idle in the night and even during daytime operate below capacity in early mornings and late afternoons. Thus, the entire expensive asset of solar farms remains highly unutilized. This thesis presents novel technologies for utilization of PV solar farm inverter in nighttime for providing multiple benefits to power systems, as well as accomplishing the same objectives during the daytime from the inverter capacity left after production of real power. The new technology transforms a solar farm inverter functionally into a dynamic reactive power compensator known as STATCOM, and termed PV-STATCOM.

A novel coordinated control of PV-STATCOMs …


Subsynchronous Resonance In Wind Farms, Akshaya Kumar Moharana Oct 2012

Subsynchronous Resonance In Wind Farms, Akshaya Kumar Moharana

Electronic Thesis and Dissertation Repository

Large-scale integration of wind farms in transmission networks has led to several challenges; one of which is the need for increased transmission capacity to transport a bulk amount of wind power. Series compensation is an established means of enhancing the power transfer capability of existing transmission lines and is being increasingly considered for integrating large wind power plants. However, series compensated transmission lines may cause subsynchronous resonance (SSR) in turbine-generators, which can lead to electrical instability at subsynchronous frequencies and potential turbine-generator shaft failures.

This thesis deals primarily with the potential of subsynchronous resonance in induction generator based wind farms …


Dynamic Model Construction And Control System Design For Canadian Supercritical Water-Cooled Reactors, Peiwei Sun Oct 2012

Dynamic Model Construction And Control System Design For Canadian Supercritical Water-Cooled Reactors, Peiwei Sun

Electronic Thesis and Dissertation Repository

The dynamic characteristics of Canadian Supercritical Water-cooled Reactor (SCWR) are significantly different from those of CANDU reactors due to the supercritical water coolant and the once-through direct cycle coolant system. Therefore, it is necessary to study its dynamic behaviour and further design adequate control system.

An accurate dynamic model is needed to describe the dynamic behaviour. Moving boundary method is applied to improve numerical accuracy and stability. In the model construction process, three regions have been considered depending on bulk and wall temperature being higher or lower than the pseudo-critical temperature. Benefits of adopting moving boundary method are illustrated in …


Enhancing Reliability In Passive Anti-Islanding Protection Schemes For Distribution Systems With Distributed Generation, Mohsen Sheikholeslamzadeh Sep 2012

Enhancing Reliability In Passive Anti-Islanding Protection Schemes For Distribution Systems With Distributed Generation, Mohsen Sheikholeslamzadeh

Electronic Thesis and Dissertation Repository

This thesis introduces a new approach to enhance the reliability of conventional passive anti-islanding protection scheme in distribution systems embedding distributed generation. This approach uses an Islanding-Dedicated System (IDS) per phase which will be logically combined with the conventional scheme, either in blocking or permissive modes. Each phase IDS is designed based on data mining techniques. The use of Artificial Neural Networks (ANNs) enables to reach higher accuracy and speed among other data mining techniques. The proposed scheme is trained and tested on a practical radial distribution system with six-1.67 MW Doubly-Fed Induction Generators (DFIG-DGs) wind turbines. Various scenarios of …


A Control Scheme For An Ac-Dc Single-Stage Buck-Boost Pfc Converter With Improved Output Ripple Reduction, Kamran Rezaei Aug 2012

A Control Scheme For An Ac-Dc Single-Stage Buck-Boost Pfc Converter With Improved Output Ripple Reduction, Kamran Rezaei

Electronic Thesis and Dissertation Repository

AC-DC power factor correction (PFC) single-stage converters are attractive because of their cost and their simplicity. In these converters, both PFC and power conversion are done at the same time using a single converter that regulates the output. Since they have only a single controller, these converters operate with an intermediate transformer primary-side DC bus voltage that is unregulated and is dependent on the converters’ operating conditions and component values. This means that the DC bus voltage can vary significantly as line and load conditions are changed. Such a variable DC bus voltage makes it difficult to optimally design the …


Technique For Measurement Of Weld Resistance For Ac Resistance Spot Welding Via Instantaneous Phasor Measurement, Mian Mohsin Irshad Aug 2012

Technique For Measurement Of Weld Resistance For Ac Resistance Spot Welding Via Instantaneous Phasor Measurement, Mian Mohsin Irshad

Electronic Thesis and Dissertation Repository

The resistance measurement in the resistance spot welding (RSW), is an ongoing research topic. The high current flow during the welding process induces an electromagnetic field in the wires which are attached to the electrodes to measure tip voltage. This results an additional voltage drop which is proportional to the derivative of current. Also the presence of silicon controlled rectifier (SCR) in the welding power supply generates harmonics in both supply voltage and current. These issues together complicate the methods for resistance estimation.

A set of simultaneous linear equations is derived for the on-line measurement of dynamic resistance and induced …


Security Aspects Of Smart Grid Communication, Pubudu E. Weerathunga Aug 2012

Security Aspects Of Smart Grid Communication, Pubudu E. Weerathunga

Electronic Thesis and Dissertation Repository

As the grid becomes highly interconnected, power protection, control, and monitoring in transmission and distribution substations are increasingly relying on digital controls and digital communication. Rapid penetrations of communication into power grid, and growing concerns about cyber security have attracted significant attention towards smart grid cyber security. Cyber security in the smart grid must be carefully designed to meet power system operation’s functional and reliability requirements.

This thesis discusses issues related to the security of power system communication and their counter measures. It focuses on development of security mechanisms for secure substation communication, and analyzes the impact of security overhead …


Investigation Of Wireless Lan For Iec 61850 Based Smart Distribution Substations, Palak P. Parikh Aug 2012

Investigation Of Wireless Lan For Iec 61850 Based Smart Distribution Substations, Palak P. Parikh

Electronic Thesis and Dissertation Repository

The IEC 61850 standard is receiving acceptance worldwide to deploy Ethernet Local Area Networks (LANs) for electrical substations in a smart grid environment. With the recent growth in wireless communication technologies, wireless Ethernet or Wireless LAN (WLAN), standardized in IEEE 802.11, is gaining interest in the power industry for substation automation applications, especially at the distribution level. Low Voltage (LV) / Medium Voltage (MV) distribution substations have comparatively low time-critical performance requirements. At the same time, expensive but high data-rate fiber-based Ethernet networks may not be a feasible solution for the MV/LV distribution network. Extensive work is carried out to …


Low Power Ac-Dc And Dc-Dc Multilevel Converters, Mehdi Narimani Jul 2012

Low Power Ac-Dc And Dc-Dc Multilevel Converters, Mehdi Narimani

Electronic Thesis and Dissertation Repository

AC-DC power electronic converters are widely used for electrical power conversion in many industrial applications such as for telecom equipment, information technology equipment, electric vehicles, space power systems and power systems based on renewable energy resources. Conventional AC-DC converters generally have two conversion stages – an AC-DC front-end stage that operates with some sort of power factor correction to ensure good power quality at the input, and a DC-DC conversion stage that takes the DC output of the front-end converter and converts it to the desired output DC voltage. Due to the cost of having two separate and independent converters, …


Design, Implementation And Evaluation Of A Microgrid In Island And Grid Connected Modes With A Fuel Cell Power Source, Andrew T. Moore Apr 2012

Design, Implementation And Evaluation Of A Microgrid In Island And Grid Connected Modes With A Fuel Cell Power Source, Andrew T. Moore

Electronic Thesis and Dissertation Repository

The ability to connect a microgrid to the grid is an important step in the development and evolution of the modern power system. The principle objectives of this research are (1) to simulate a simple microgrid consisting of a PEM hydrogen fuel cell, load and connection to the grid and (2) to evaluate the resulting microgrid control system on a corresponding experimental microgrid.

The microgrid simulation demonstrated that the control algorithms can operate the microgrid in both islanded (VSC with voltage and frequency regulation) and grid connected (VSC with current control for power transfer).

The experimental laboratory microgrid was constructed …


A New Zvs-Pwm Full-Bridge Boost Converter, Mohammadjavad Baei Mar 2012

A New Zvs-Pwm Full-Bridge Boost Converter, Mohammadjavad Baei

Electronic Thesis and Dissertation Repository

Pulse-width modulated (PWM) full-bridge boost converters are used in applications where the output voltage is considerably higher than the input voltage. Zero-voltage-switching (ZVS) is typically implemented in these converters. The objective of this thesis is to propose, analyze, design, implement, and experimentally confirm the operation of a new Zero-Voltage-Switching PWM DC-DC full-bridge boost converter that does not have any of the drawbacks that other converters of this type have, such as a complicated auxiliary circuit, increased current stresses in the main power switches and load dependent ZVS operation. In this thesis, the general operating principles of the converter are reviewed, …


Investigation On The Benefits Of Safety Margin Improvement In Candu Nuclear Power Plant Using An Fpga-Based Shutdown System, Jingke She Mar 2012

Investigation On The Benefits Of Safety Margin Improvement In Candu Nuclear Power Plant Using An Fpga-Based Shutdown System, Jingke She

Electronic Thesis and Dissertation Repository

The relationship between response time and safety margin of CANadian Deuterium Uranium (CANDU) nuclear power plant (NPP) is investigated in this thesis. Implementation of safety shutdown system using Field Programmable Gate Array (FPGA) is explored. The fast data processing capability of FPGAs shortens the response time of CANDU shutdown systems (SDS) such that the impact of accident transient can be reduced. The safety margin, which is closely related to the reactor behavior in the event of an accident, is improved as a result of such a faster shutdown process.

Theoretical analysis based on neutron dynamic theory is carried out to …