BIDIRECTIONAL AC-DC CONVERTERS USING ONE CYCLE CONTROL (OCC) FOR ELECTRIC VEHICLES

The electric vehicle (EV) market has seen a rapid growth in the recent past. With an increase in the number of electric vehicles on road, there is an increase in the number of high capacity battery banks interfacing the grid. The battery bank of an EV, besides being the fuel tank, is also a huge energy storage unit. Presently, it is used only when the vehicle is being driven and remains idle for rest of the time, rendering it underutilized. Whereas on the other hand, there is a need of large energy storage units in the grid to filter out the fluctuations of supply and demand during a day. EVs can help bridge this gap. The EV battery bank can be used to store the excess energy from the grid to vehicle (G2V) or supply stored energy from the vehicle to grid (V2G ), when required. To let power flow happen, in both directions, a bidirectional AC-DC converter is required. This thesis concentrates on the bidirectional AC-DC converters which have a control on power flow in all four quadrants for the application of EV battery interfacing with the grid. This thesis presents a bidirectional interleaved full bridge converter topology. This helps in increasing the power processing and current handling capability of the converter which makes it suitable for the purpose of EVs. Further, the benefit of using the interleaved topology is that it increases the power density of the converter. This ensures optimization of space usage with the same power handling capacity. The proposed interleaved converter consists of two full bridges. The corresponding gate pulses of each switch, in one cell, are phase shifted by 180 degrees from those of the other cell. The proposed converter control is based on the one-cycle controller. To meet the challenge of new requirements of reactive power handling capabilities for grid connected converters, posed by the utilities, the controller is modified to make it suitable to process the reactive power. A fictitious current derived from the grid voltage is introduced in the controller, which controls the converter performance. The current references are generated using the second order generalized integrators (SOGI) and phase locked loop (PLL). A digital implementation of the proposed control ii scheme is developed and implemented using DSP hardware. The simulated and experimental results, based on the converter topology and control technique discussed here, are presented to show the performance of the proposed theory.

Study Abroad Course Development: Pre-Departure Sessions

Study abroad is a highly encouraged component of the undergrad business program at Bella Lake University, with the large majority of undergraduate students choosing to study and live in a foreign country to expand on their international experiences. Currently, there is no learning structure or learning outcome expectation for students that will participate in the study abroad experience. This project focuses on the development of a course that supports students in the pre-departure phase of their study abroad journey and prepares them to set goals, understand the learning process and the practices of experiential learning to encourage students to achieve both personal and professional goals, and encourage the development of intercultural competence. The discourse surrounding the perceptions and efficacy of the course development is based on a self-assessment survey completed by 121 undergraduate business students that participated in the pre-departure sessions prior to leaving for study abroad in March 2016. The self-assessment results overall showed that the course achieved its aims with the majority of students rating that they were more likely to understand and engage in experiential learning, set goals for their study abroad experience and felt more prepared for study abroad after attending the pre-departure sessions. The project concludes that in order for the pre-departure course to maintain its value, the conversation with students surrounding experiential learning in study abroad needs to continue with further course development focusing on both during and post-study abroad. Further exploration can also be done to find varying ways to motivate different students to engage in the learning potential of study abroad.