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Full-Text Articles in Engineering

Optimal Decentralized Coordination Of Sources In Islanded And Grid-Connected Microgrids, Mithun Mallick Jul 2019

Optimal Decentralized Coordination Of Sources In Islanded And Grid-Connected Microgrids, Mithun Mallick

Electronic Thesis and Dissertation Repository

Rising climate change concerns in recent years have instigated the emergence of sustainable sources to reduce dependence on high-emission, isolated bulk generation systems. The microgrid framework relies on integrating these distributed energy resources (DERs) to achieve regional energy independence that leads to a reliable and environment-friendly power grid. In this work, highly granular and decentralized coordination schemes are proposed that will enable fast computation of source dispatch set-points, thereby appropriately accounting for frequent changes in regional load-supply configuration of a microgrid. The mathematical models utilized in the study sufficiently represent the steady-state electrical interdependencies and feasibility limits in islanded or ...


Continuous Monitoring Of Neutral Grounding Resistors And Reactors, Rahim Jafari Nov 2018

Continuous Monitoring Of Neutral Grounding Resistors And Reactors, Rahim Jafari

Electronic Thesis and Dissertation Repository

Electrical power system components are designed three-phase balanced and symmetric with the internal connection of wye or delta. The common point of the wye-connected equipment, which is called neutral, is impedance grounded for many reasons such as fault ride through by controlling transient overvoltages, and limiting the ground overcurrents. Depending on the application, different neutral impedance grounding methods exist that employ resistors or reactors with/without neutral grounding transformers. These apparatuses are known as Neutral Grounding Devices (NGD). The most well-known sort of NGDsarethe Neutral Grounding Resistor (NGR) and Neutral Grounding Reactor (NGL) which are the main focus of this ...


Spectral And Energy Efficient Communication Systems And Networks, Abdulbaset Hamed Oct 2018

Spectral And Energy Efficient Communication Systems And Networks, Abdulbaset Hamed

Electronic Thesis and Dissertation Repository

In this thesis, design and analysis of energy- and spectral-efficient communication and cellular systems in micro wave and millimeter wave bands are considered using the following system performance metrics: i) Energy efficiency; ii) Spectral efficiency; iii) Spatial spectral efficiency; iv) Spatial energy efficiency, and v) Bit error rate. Statistical channel distributions, Nakagami-m and Generalized-K, and path loss models, Line of Sight (LOS) and Non-Line of Sight (NLOS), are used to represent the propagation environment in these systems. Adaptive M-QAM and M-CPFSK communication systems are proposed to enhance their efficiency metrics as a function of Signal-to-Noise Ratio (SNR) over the channel ...


Non-Pilot Protection Of The Inverter-Dominated Ac Microgrid, Houman Lahiji Sep 2018

Non-Pilot Protection Of The Inverter-Dominated Ac Microgrid, Houman Lahiji

Electronic Thesis and Dissertation Repository

The main objective of this research is to develop reliable non-pilot protection and control strategies for the inverter-dominated microgrid. First, an improved Proportional-Derivative (PD) droop control strategy is proposed for enhanced disturbance response of the inverter-dominated AC microgrid. The proposed strategy significantly improves microgrid dynamic response and stability without requiring communication between distributed energy resources. Moreover, the impacts of large startup currents of induction motors on the stability and power quality of the inverter-dominated microgrid are investigates and recommendations for minimizing the associated adverse effects are made.

Subsequently, a fast, selective, and reliable protection strategy for the inverter-dominated microgrid is ...


New Algorithms For Locating Faults In Series Capacitive Compensated Transmission Lines, Tirath Bains Sep 2018

New Algorithms For Locating Faults In Series Capacitive Compensated Transmission Lines, Tirath Bains

Electronic Thesis and Dissertation Repository

The precise location of the fault in a series capacitive compensated transmission line (SCCTL) plays an integral part in limiting the maintenance time following its tripping due to the occurrence of a permanent fault. Since, an SCCTL acts as a huge corridor of power, its outage will result in huge monetary losses which are directly proportion to the time it remains out of service. In worst case scenario, the tripping of an SCCTL might lead to the cascaded tripping of the parallel transmission lines due to overloading. Therefore, the need for an accurate and robust fault location algorithm for the ...


Transformerless High-Power Medium-Voltage Multi-Module Pv Converters, Hasan Bayat Jul 2018

Transformerless High-Power Medium-Voltage Multi-Module Pv Converters, Hasan Bayat

Electronic Thesis and Dissertation Repository

This thesis is focused on the modular multilevel converter (MMC) for Photovoltaic (PV) applications. It is an attempt to address the issues associated with the modeling, control, and power mismatch elimination of the MMC-based PV systems. Firstly, a new real power reference generation scheme is proposed that creates a linear relationship between the real power reference of the system and the dc link voltage of the submodules. Further, a new power mismatch elimination strategy is proposed for the MMC-based PV system which ensures balanced currents are delivered to the host grid regardless of leg and arm power mismatches. The thesis ...


A High Gain Dc-Dc Full-Bridge Converter, Prashanth Prabhu Jan 2018

A High Gain Dc-Dc Full-Bridge Converter, Prashanth Prabhu

Electronic Thesis and Dissertation Repository

High gain DC-DC converters have become increasingly popular in recent years as there is greater need to interface low voltage DC sources such as solar cells and batteries with much higher voltage DC buses. A new high gain DC-DC converter with high gain, galvanic isolation and an integrated passive snubber network is proposed in the thesis. In the thesis, the general operation of the converter is discussed, its modes of operation are explained and its features are reviewed. The design of the converter is then discussed and a set of general guidelines that can be used in the design are ...


A New Single-Phase Single-Stage Ac-Dc Stacked Flyback Converter With Active Clamp Zvs, Yuntong Li Dec 2017

A New Single-Phase Single-Stage Ac-Dc Stacked Flyback Converter With Active Clamp Zvs, Yuntong Li

Electronic Thesis and Dissertation Repository

Single-stage AC-DC converters integrate an AC-DC front-end converter with a DC-DC back-end converter. Compared with conventional two-stage AC-DC converters, single-stage AC-DC converters use less components and only one controller, which is used to regulate the output voltage. As a result, the cost, size and complexity of AC-DC converters can be reduced, but single-stage converters do not perform as well as two-stage converters, and most have drawbacks that are related to the fact that the DC bus voltage is not controlled an can become excessive.

A new single-phase single-stage AC-DC converter that uses stacked flyback converters is proposed in this thesis ...


A Novel Ac-Dc Interleaved Zcs-Pwm Boost Converter, Ramtin Rasoulinezhad Dec 2017

A Novel Ac-Dc Interleaved Zcs-Pwm Boost Converter, Ramtin Rasoulinezhad

Electronic Thesis and Dissertation Repository

AC-DC converters with input power factor correction (PFC) that consist of two or more interleaved boost converter modules are popular in industry. PFC is a must in today’s AC-DC converters as their input current must meet harmonic standards set by regulatory agencies. With interleaving, the input current of each module can make to be discontinuous and the size of their input inductors since interleaving can reduce the high ripple in each module and produce a net input current with a ripple that is comparable to that achieved with a single boost converter module with a large input inductor.

In ...


A Comparison Between Different Snubbers For Flyback Converters, Adel Alganidi Dec 2017

A Comparison Between Different Snubbers For Flyback Converters, Adel Alganidi

Electronic Thesis and Dissertation Repository

The DC-DC flyback power converter is widely used in low power commercial and industrial applications ( > 150 W) such as in computers, telecom, consumer electronics because it is one of the simplest and least expensive converter topologies with transformer isolation. Its main power circuit consists of just a semiconductor device like a MOSFET operating as a switch, a transformer, an output diode and an output filter capacitor. The converter switch, however, is susceptible to high voltage spikes due to the interaction between its output capacitance and the leakage inductance of the transformer. These spikes can exceed the ratings of the switch ...


Novel Night And Day Control Of A Pv Solar System As A Statcom (Pv-Statcom) For Damping Of Power Oscillations, Hesamaldin Maleki Oct 2017

Novel Night And Day Control Of A Pv Solar System As A Statcom (Pv-Statcom) For Damping Of Power Oscillations, Hesamaldin Maleki

Electronic Thesis and Dissertation Repository

Installations of large scale PV solar farms are rapidly increasing, worldwide. This is causing a growing apprehension that inertialess power injections from these inverter based generators will result in a decline in power system stability. Instead, this thesis presents novel applications of a patent pending technology whereby the PV solar farms actually help significantly increase system stability. A novel 24/7 (night and day) control of a large-scale PV solar farm as a dynamic reactive power compensator STATCOM, termed PV-STATCOM, is presented for damping low-frequency electromechanical power oscillations resulting in a significant improvement in power transfer capability of existing power ...


Fault Location In High Voltage Shunt Capacitor Banks, Hessamoddin Jouybari Moghaddam Aug 2017

Fault Location In High Voltage Shunt Capacitor Banks, Hessamoddin Jouybari Moghaddam

Electronic Thesis and Dissertation Repository

High Voltage Shunt Capacitor Banks (HV-SCBs) are critical substation assets that are primarily used to improve power factor and thus power transmission capability. Over temperature, over voltages, manufacturing defects can cause internal failures of capacitor elements. With today’s sensitive protection available in numerical relays these failures will be detected and SCBs will be taken out of service. But determining the phase and section in which capacitor elements have failed is important for utilities to decrease downtime of SCBs. This thesis proposes methods to address the challenges in fault location of SCBs. The proposed methods apply calibrating factors that compensate ...


Predictive Energy Management Of Islanded Microgrids With Photovoltaics And Energy Storage, Dennis G. Michaelson Jul 2017

Predictive Energy Management Of Islanded Microgrids With Photovoltaics And Energy Storage, Dennis G. Michaelson

Electronic Thesis and Dissertation Repository

Islanded microgrids powered primarily by photovoltaic (PV) arrays present a challenging control problem due to the intermittent production and the relatively close scale between the sources and the loads. Energy storage in such microgrids plays an important role in balancing supply with demand, and in extending operation during periods when the PV supply is not available or insufficient. The efficient operation of such microgrids requires effective management of all resources. A predictive energy management strategy can potentially avoid or effectively mitigate upcoming outages. This thesis presents an energy management system (EMS) for such microgrids. The EMS uses a predictive approach ...


Numerical And Experimental Study Of The Trichel Pulses In Needle-Plane Geometry, Peyman Dordizadeh Basirabad Sep 2016

Numerical And Experimental Study Of The Trichel Pulses In Needle-Plane Geometry, Peyman Dordizadeh Basirabad

Electronic Thesis and Dissertation Repository

One of the unique aspects of the negative corona discharges in the air is the regular train of pulses that form the discharge current, called Trichel pulses. These pulses are the result of the combination of several phenomena such as the avalanche ionization of the neutral molecules by the impact of the energized electrons, formation of the cloud of positive ions close to the cathode, and formation of the cloud of negative ions at a farther distance from the corona electrode compared to their positive counterparts. In this thesis, the results of a detailed numerical investigation of the formation of ...


Analysis And Mitigation Of Temporary Over-Voltage (Tov) Phenomenon In Unintentionally Islanded Grid-Connected Photovoltaic (Pv) Inverters, Md Maruful Islam Aug 2016

Analysis And Mitigation Of Temporary Over-Voltage (Tov) Phenomenon In Unintentionally Islanded Grid-Connected Photovoltaic (Pv) Inverters, Md Maruful Islam

Electronic Thesis and Dissertation Repository

Grid-connected photovoltaic (PV) solar systems, like other inverter-based distributed generators, can cause temporary over-voltages (TOVs), especially subsequent to faults and unintentional islanding incidents, and can damage equipment and customers within the host distribution network. Thus, this thesis aims to study the phenomenon and propose corrective measures for it. Thus, the thesis first presents detailed models for a conventional single-stage PV system and a modified single-stage PV system. The conventional system uses a Δ/YG isolation transformer, whereas the modified system, proposed in the literature, assumes a Y/YG isolation transformer that is effectively grounded by an additional half-bridge leg energized ...


Optimal Scheduling Of Energy Storage For Energy Shifting And Ancillary Services To The Grid, Hadi Khani Aug 2016

Optimal Scheduling Of Energy Storage For Energy Shifting And Ancillary Services To The Grid, Hadi Khani

Electronic Thesis and Dissertation Repository

This thesis is mainly focused on developing optimization-based models for scheduling of energy storage units. At first, a real-time optimal scheduling algorithm is developed seeking to maximize the storage revenue by exploiting arbitrage opportunities available due to the inter-temporal variation of electricity prices. The electricity price modulation is proposed as an approach to competitively offer incentive by the utility regulator to storage to fill the gap between current and a stable rate of return. Subsequently, the application of large-scale storage for congestion relief in transmission systems as an ancillary service to the grid is investigated. An algorithm is proposed for ...


State Space Modeling Of Smart Pv Inverter As Statcom (Pv-Statcom) For Voltage Control In A Distribution System, Sridhar Bala Subramanian May 2016

State Space Modeling Of Smart Pv Inverter As Statcom (Pv-Statcom) For Voltage Control In A Distribution System, Sridhar Bala Subramanian

Electronic Thesis and Dissertation Repository

The grid integration of photovoltaic (PV) systems in distribution networks is facing challenges such as transient changes in voltage due to fluctuations in generated real power and tripping of PV systems. Smart PV inverters with functions such as dynamic reactive current injection and low voltage ride through are available to mitigate these challenges. This thesis shows that a better stable performance can be obtained if these functions are implemented using the novel patent-pending technology of PV system as a dynamic reactive power compensator (PV-STATCOM). A linearized state space model of PV-STATCOM is developed to show the benefits of PV-STATCOM controls ...


Sensorless Rotor Position Estimation For Brushless Dc Motors, Iram G. Raza Apr 2016

Sensorless Rotor Position Estimation For Brushless Dc Motors, Iram G. Raza

Electronic Thesis and Dissertation Repository

Brushless DC motor speed is controlled by synchronizing the stator coil current with rotor position in order to acquire an accurate alignment of stator rotating field with rotor permanent-magnet field for efficient transfer of energy. In order to accomplish this goal, a motor shaft is instantly tracked by using rotating rotor position sensors such as Hall effect sensors, optical encoders or resolvers etc. Adding sensors to detect rotor position affects the overall reliability and mechanical robustness of the system. Therefore, a whole new trend of replacing position sensors with sensorless rotor position estimation techniques have a promising demand.

Among the ...


Adaptive Single-Phase Reclosing In Transmission Lines, Farzad Zhalefar Nov 2015

Adaptive Single-Phase Reclosing In Transmission Lines, Farzad Zhalefar

Electronic Thesis and Dissertation Repository

This research work is mainly concerned about dealing with temporary short circuit faults in power system transmission lines. In fact, there are two types of electrical faults in power systems, namely temporary and permanent. When a fault is permanent, the only way to clear it is to de-energize the transmission line by opening the associated circuit breakers. However, in many cases the fault is not solid and is caused by objects such as flying birds or broken branches of trees. For these cases, electrical arc plays a major role. For such fault cases, it is also possible to de-energize the ...


Modeling, Construction, And Validation Of A Simulator For A Nuclear Process Control Test Facility, Binggang Cui Sep 2015

Modeling, Construction, And Validation Of A Simulator For A Nuclear Process Control Test Facility, Binggang Cui

Electronic Thesis and Dissertation Repository

This thesis presents the modeling, construction, and validation of a software simulator for a facility with physical components, referred to as NPCTF (Nuclear Process Control Test Facility). The simulator focuses simulation functionalities on dynamic behaviours of thermal-hydraulic systems related to nuclear power plants.

The modeling techniques adopted to construct the simulator are based on physical principles. Dynamic models are developed to reproduce the dynamic characteristics of NPCTF. Based on these mathematical relationships, computer codes are developed with the toolbox Simscape. The simulator can be used to investigate specific scenarios of NPCTF under similar operating conditions.

A simulation environment, the toolbox ...


Secondary Electrohydrodynamic Flow Generated By Corona And Dielectric Barrier Discharges, Mohammadreza Ghazanchaei Sep 2015

Secondary Electrohydrodynamic Flow Generated By Corona And Dielectric Barrier Discharges, Mohammadreza Ghazanchaei

Electronic Thesis and Dissertation Repository

One of the main goals of applied electrostatics engineering is to discover new perspectives in a wide range of research areas. Controlling the fluid media through electrostatic forces has brought new important scientific and industrial applications. Electric field induced flows, or electrohydrodynamics (EHD), have shown promise in the field of fluid dynamics. Although numerous EHD applications have been explored and extensively studied so far, most of the works are either experimental studies, which are not capable to explain the in depth physics of the phenomena, or detailed analytical studies, which are not time effective. The focus of this study is ...


Real Time Testing And Validation Of A Novel Short Circuit Current (Scc) Controller For A Photovoltaic Inverter, Vishwajitsinh H. Atodaria Aug 2015

Real Time Testing And Validation Of A Novel Short Circuit Current (Scc) Controller For A Photovoltaic Inverter, Vishwajitsinh H. Atodaria

Electronic Thesis and Dissertation Repository

About 45% applications from PV solar farm developers seeking connections to the distribution grids in Ontario were denied in 2011-13 as the short circuit current (SCC) capacity of several distribution substations had already been reached. PV solar system inverters typically contribute 1.2 p.u. to 1.8 p.u. fault current which was not considered acceptable by utility companies due to the need for very expensive protective breaker upgrades. Since then, this cause has become a major impediment in the growth of PV based renewable systems in Ontario.

A novel predictive technique has been patented in our research group ...


Smart Pv Inverter Control For Distribution Systems, Ehsan M. Siavashi Aug 2015

Smart Pv Inverter Control For Distribution Systems, Ehsan M. Siavashi

Electronic Thesis and Dissertation Repository

PV solar systems employ inverters to transform dc power from solar panels into ac power for injecting into the power grids. Inverters that perform multiple functions in addition to real power production are known as “smart inverters”.

This thesis presents a novel control of PV inverter as a dynamic reactive power compensator – STATCOM. This “smart PV inverter” control enables a PV solar inverter to operate in three modes – i) Full PV, ii) Partial STATCOM, and iii) Full STATCOM, depending upon system needs. The novel control is developed and demonstrated for the objectives of a) symmetrical voltage regulation, b) temporary overvoltage ...


Control System Design, Analysis, And Simulation Of A Photovoltaic Inverter For Unbalanced Load Compensation In A Microgrid, Elizabeth K. Tomaszewski May 2015

Control System Design, Analysis, And Simulation Of A Photovoltaic Inverter For Unbalanced Load Compensation In A Microgrid, Elizabeth K. Tomaszewski

Electronic Thesis and Dissertation Repository

This thesis presents a control scheme for a single-stage three-phase Photovoltaic (PV) converter with negative sequence load current compensation.

In this thesis a dual virtual impedance active damping technique for an LCL filter is proposed to address the issue of LCL filter resonance. Both inverter-side current and the capacitor current are used in the feedback loop. Using both signals provides higher DC rejection than using capacitor current alone. The proposed active damping scheme results in a faster transient response and higher damping ratio than can be obtained using inverter-side current alone. The feedback gains can be calculated to achieve a ...


Power Management Strategies For A Wind Energy Source In An Isolated Microgrid And Grid Connected System, Devbratta Thakur Apr 2015

Power Management Strategies For A Wind Energy Source In An Isolated Microgrid And Grid Connected System, Devbratta Thakur

Electronic Thesis and Dissertation Repository

This thesis focuses on the development of power management control strategies for a direct drive permanent magnet synchronous generator (PMSG) based variable speed wind turbine (VSWT). Two modes of operation have been considered: (1) isolated/islanded mode, and (2) grid-connected mode.

In the isolated/islanded mode, the system requires additional energy sources and sinks to counterbalance the intermittent nature of the wind. Thus, battery energy storage and photovoltaic (PV) systems have been integrated with the wind turbine to form a microgrid with hybrid energy sources. For the wind/battery hybrid system, several energy management and control issues have been addressed ...


Power Management Strategies For Islanded Microgrids, Hisham Mahmood Dec 2014

Power Management Strategies For Islanded Microgrids, Hisham Mahmood

Electronic Thesis and Dissertation Repository

The focus of this thesis is on developing power management strategies for islanded microgrids, at the primary and the secondary hierarchal control layers. At the Primary Control Layer, the main objective of the proposed strategies is to achieve decentralized power management of Photovoltaic (PV) and battery storage in islanded microgrids. In contrast to the common approach of controlling the PV unit as a current source, in the proposed strategies, the PV unit is controlled as a voltage source that follows a multi-segment adaptive power/frequency characteristic curve. The strategies are implemented locally at the units using multi-loop controllers without relying ...


A Dc Distribution System For Power System Integration Of Plug-In Electric Vehicles; Modeling, Stability And Operation, Mansour Tabari Nov 2014

A Dc Distribution System For Power System Integration Of Plug-In Electric Vehicles; Modeling, Stability And Operation, Mansour Tabari

Electronic Thesis and Dissertation Repository

This thesis is mainly focused on (i) modeling of dc distribution systems for power system integration of plug-in electric vehicles (PEVs), (ii) proposing a method to enhance the stability of the dc distribution systems, and (iii) proposing an energy management strategy to control the power flow in the dc distribution system. The dc distribution system is expected to be more efficient and economical than a system of ac-dc battery chargers directly interfaced with an ac grid.

In the first part, a systematic method for developing a model for a dc distribution system, based on the configuration of the system is ...


Optimal Sizing And Power Management Strategies Of Islanded Microgrids For Remote Electrification Systems, Faruk A. Bhuiyan Sep 2014

Optimal Sizing And Power Management Strategies Of Islanded Microgrids For Remote Electrification Systems, Faruk A. Bhuiyan

Electronic Thesis and Dissertation Repository

Over the past few years, electrification of remote communities with an efficient utilization of on-site energy resources has entered a new phase of evolution. However, the planning tools and studies for the remote microgrids are considered inadequate. Moreover, the existing techniques have not taken into account the impact of reactive power on component sizes. Thus, this thesis concentrates on optimal sizing design of an islanded microgrid (IMG), which is composed of renewable energy resources (RERs), battery energy storage system (BESS), and diesel generation system (DGS), for the purpose of electrifying off-grid communities. Owing to the utilization of both BESS and ...


Comprehensive Statcom Control For Distribution And Transmission System Applications, Shubham Gupta Aug 2014

Comprehensive Statcom Control For Distribution And Transmission System Applications, Shubham Gupta

Electronic Thesis and Dissertation Repository

This thesis presents the development of a comprehensive STATCOM controller for load compensation, voltage regulation and voltage balancing in electric power distribution and transmission networks. The behavior of this controller is first validated with published results. Subsequently, the performance of this STATCOM controller is examined in a realistic Hydro One distribution feeder for accomplishing the compensation of both mildly and grossly unbalanced loads, and balancing of network voltages using PSCAD/EMTDC software. The STATCOM voltage control function is utilized for increasing the connectivity of wind plants in the same distribution feeder. The thesis further presents a frequency scanning technique for ...


Fault Location In Series Compensated Transmission Lines, Tirath Pal Singh Bains Aug 2014

Fault Location In Series Compensated Transmission Lines, Tirath Pal Singh Bains

Electronic Thesis and Dissertation Repository

Due to the integration of modern technology such as electric vehicles, the emphasis is expected to shift from mechanical to electric power. Therefore, the need of increasing the power transmission capacity of the electric grid gets highlighted. Since, the construction of transmission lines is a tedious task owing to legalities, environmental impacts and high costs, the series compensated transmission lines are gaining popularity due to lesser costs and faster construction time. The series capacitor compensated transmission lines are very crucial lines due to the greater power being transmitted through them. Therefore, an accurate fault location becomes a prerequisite for limiting ...