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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Advanced topologies and control for high-efficiency bidirectional power converters for use in electric vehicles with on-board solar generation

Zheng, Pengfei 11 1900 (has links)
Electric vehicles (EVs) offer significant advantages over conventional internal combustion engine vehicles, including zero emissions and convenient overnight charging. However, there are still several challenges that need to be addressed. These challenges include limited driving ranges, slow refueling options while on-the-go, concerns related to the supply of lithium for batteries, and emissions associated with certain sources of electricity generation, such as coal. Adding on-board solar generation and/or fuel cell range extenders to EVs can help to mitigate some of these challenges, but also adds the need for optimal power electronic converters to manage the power flow of these multiple on-board energy sources, which is the focus of this thesis. This thesis first performs a comprehensive review of EV onboard chargers (OBCs) including charger system requirements by different standards and codes and different DC/DC power converters in the current infrastructures. Various power levels are compared and evaluated based on their component ratings, efficiency, cost, and power density. Secondly, there has been recent interest in harnessing solar power within electric vehicles, leading to the emergence of solar-charged electric vehicles (SEVs), which can offer extended driving ranges and less need for grid charging. These vehicles also offer a new opportunity for distributed generation when their traction batteries are fully charged, and the plugged-in vehicle is still generating solar energy. However, this also presents a unique power electronic dilemma. The OBC must exhibit high efficiency in two scenarios: firstly, during normal charging from the grid at power levels around 6.6 kW, and secondly, during vehicle-to-grid operation at significantly lower solar power levels, typically below 800 W. Unfortunately, conventional OBC designs tend to have low efficiency when operating at light loads. To tackle this challenge, this thesis proposes a novel bidirectional LLC-based converter, for use within the OBC, that achieves higher vehicle-to-grid efficiency at light loads than a traditional dual bridge converter. Detailed PLECS simulation results and experimental results are presented to verify the circuit. Thirdly, the presence of manufacturing variations can introduce parameter mismatches, resulting in voltage imbalances across capacitors in the proposed converter, or in other resonant converters with multiple transformer windings and two series-connected capacitors with a center connection. Such voltage imbalances pose significant concerns regarding safety and reliability. However, the existing capacitor balancing strategies developed for other converter topologies are not directly applicable to these new resonant multi-winding topologies. To address this issue, this thesis presents a novel method for achieving capacitor voltage balancing in a resonant multi-winding converter. The proposed method employs a straightforward approach to determine the appropriate balancing switching states. Time domain analysis is conducted to quantify the number of control cycles required, and an adaptive control strategy is introduced to enhance the balancing performance. The effectiveness of the proposed method and the beneficial effects on the converter's efficiency and bus capacitor sizes are validated through experimental investigations involving multiple bus capacitor sizes. Finally, though SEVs offer advantages over non-solar EVs, some challenges remain such as lithium supply concerns for large batteries, slow recharging, and driving range that is still limited compared to conventional vehicles. Fuel cell range-extended vehicles (FCREVs) can add a small fuel cell and hydrogen tank to allow quick refueling for long trips, and still use a reduced-size plug-in battery for the majority of short trips. This allows the driver to use efficient and convenient overnight charging for most daily commutes, and refuel with hydrogen on long-distance driving days if hydrogen stations are available. The smaller battery means that lithium requirements are reduced. Further, by adding on-board solar generation to a FCREV (S-FCREV), range can be further extended and grid charging requirements can be reduced. However, using conventional separate converters for a S-FCREV would be complex and costly, having a high number of semiconductor devices. To overcome this, the thesis proposes a practical multi-port converter that fulfills S-FCREV requirements with reduced components. A novel triple PWM and triple phase shift (TPTPS) control is proposed. Simulation and experimental results validate the proposed topology's operation and efficiency, offering a promising solution for integrating power electronics in S-FCREV applications. / Thesis / Doctor of Philosophy (PhD) / In the pursuit of sustainable transportation, recent scholarly investigations have placed significant emphasis on the advancement of electric vehicles (EVs) with a particular focus on solar-charged EVs and fuel cell range-extended vehicles (FCREVs) in order to help mitigate some of the drawbacks of battery EVs such as limited driving range, long refueling times, and charging impacts on the grid. Power electronic converters play a crucial role in managing the transfer of power between multiple energy sources, such as on-board solar panels, fuel cells, batteries, and connection to the grid. The objective of this thesis is to propose novel topologies and control for power electronic converters in solar-charged EVs and solar-charged FCREVs. Firstly, a novel bidirectional DC/DC topology is proposed for solar-charged EVs that allows a high-efficiency transfer of excess solar energy to the grid when the EV battery is full. Additionally, a novel control methodology for balancing the DC bus capacitors is introduced, aiming to reduce capacitor size and mitigate circulating unbalanced currents. Lastly, this thesis presents the pioneering practical implementation of a multi-port converter for a solar-charged FCREV, along with its adaptable control approach, enabling efficient power flow management among the grid, on-board battery, solar panels, and fuel cell.
2

Range Extender Development for Electric Vehicle Using Engine Generator Set

Ambaripeta, Hari Prasad 18 March 2015 (has links)
No description available.
3

Mission-based Design Space Exploration and Traffic-in-the-Loop Simulation for a Range-Extended Plug-in Hybrid Delivery Vehicle

Anil, Vijay Sankar January 2020 (has links)
No description available.
4

Investigating The Suitability of Electrified Powertrain Alternatives for Refuse Trucks with Emphasis in The City of Hamilton

Toller, Jack 11 1900 (has links)
Refuse trucks, commonly referred to as garbage trucks are a critical component of a municipality’s waste management industry. Their primary purpose is to collect, transport and deposit waste from households or businesses to designated transfer sites or dumps. Historically, refuse trucks have been powered by diesel fuel. The consumption of diesel fuel paired with the frequent accelerations or decelerations between each residential household along a route attribute to high amounts of tailpipe emissions and noise pollution within neighbourhoods. There is significant opportunity to explore avenues of powertrain electrification in refuse trucks to reduce their emissions and improve energy efficiency. To rapidly test promising powertrains, vehicle software models were developed. To accurately model the energy usage and power requirements of refuse trucks, environments for the models to operate were created. The environments were created using on-board diagnostic and positional data collected from refuse trucks in the City of Hamilton in Ontario, Canada. The data collection was done under a research collaboration between the City of Hamilton and the McMaster Automotive Resource Centre. The approaches used to develop the drive and duty cycles for the vehicle models offer some innovative approaches without the need for invasive devices to be installed. The powertrains that were modelled includes an all-electric, ranged extended electric and conventional refuse trucks. A comparative analysis of the pump-to-wheel powertrain efficiencies were completed looking at metrics such as fuel economy, payload capacity and fuel costs. Lastly, a look at truck emissions from a well-to-wheel perspective were completed to investigate the impact of each powertrain on greenhouse gasses and the effect on air quality of their immediate surroundings. / Thesis / Master of Applied Science (MASc)

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