Concerns with emissions, CO2 in particular, and energy resource associated with conventional internal combustion engine (ICE) vehicles is motivating a shift towards more electrified power-trains for road transportation, as well as other transportation applications. The modelling, characterization and design of electrified power-trains, including energy storage technologies, traction machine technologies and their associated power electronics, are discussed in this thesis.
Port cranes are a special case of land transportation encompassing many of the power-train objectives found common with road based hybrid electric vehicles; here a port crane system is studied. The power flow for a typical crane loading cycle is analyzed and the value of the energy consumption and saving potential is calculated. Then alternative energy storage applications are considered for hybrid power-train configurations employing diesel engine generators, battery packs, supercapacitors (SCs), and flywheels. A hybrid rubber tyred gantry crane (RTGC) power-train model with power management is developed and the battery-SC hybrid energy storage systems are designed for both short- and long-period operation.
The Induction machine (IM) is a popular technology for traction applications. Although many publications discuss IM design to realize a traction torque-speed characteristic, the IM model is studied to determine the main parameters impacting on the machine performance capability at constant torque and extended speed. Based on the model analysis, an IM design procedure for traction applications is proposed which improves machine performance capability. The machine design parameters are normalized in per unit form and hence the proposed design procedure is applicable across different ratings.
In the specification and definition of vehicle power-trains, it is common (in industry) to quote data at specific operating conditions, for example, full or fixed battery terminal voltage and system temperature. The interactive influence between energy storage devices and the vehicle system is investigated. Using the all-electric Nissan Leaf power-train as a reference example, the Nissan Leaf traction system is evaluated and performance assessed by considering DC-link voltage variation from battery full state of charge (SoC) to zero SoC and temperature variations typical of an automotive application, showing that the system stated performance is reduced as battery SoC decreases. An alternative traction machine design is proposed to satisfy the vehicle target performance requirements over the complete variation of SoC. The vehicle power-train is then modified with the inclusion of a DC/DC converter between the vehicle battery and DC-link to maintain the traction system DC-link voltage near constant. A supercapacitor system is also considered for improved system voltage management. The trade-offs between the actual Nissan Leaf power-train and the redesigned systems are discussed in terms of electronic and machine packaging, and mitigation of faulted operation at high speeds.
Using the Nissan Leaf interior permanent magnet (IPM) machine as the benchmark machine, an example surface permanent magnet (SPM) machine, with same design constraints, is designed and compared with the benchmark IPM machine. The phase voltage distortion of IPM and SPM machines are compared and the mechanisms are revealed. An alternative machine topology with pole shoe rotor is proposed for reduction of machine peak current rating and voltage distortion. The pole shoe topology is common in industrial variable speed drives employing constant torque regimes, but not for traction. Here, the machine with pole shoe rotor is designed to achieve traction performance. The pole shoe concept for vehicle traction is significantly different from existing practice in the electric and hybrid electric automotive industry and thus departure in standard design is a contribution of this thesis. / Thesis / Doctor of Philosophy (PhD)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/21466 |
| Date | January 2017 |
| Creators | Zhao, Nan |
| Contributors | Schofield, Nigel, Electrical and Computer Engineering |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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