A GALLIUM NITRIDE INTEGRATED ONBOARD CHARGER

Compared to Silicon metal–oxide–semiconductor field-effect transistors (MOSFETs), Gallium Nitride (GaN) devices have a significant reduction in gate charge, output capacitance, and zero reverse recovery charge, enabling higher switching frequency operation and efficient power conversion. GaN devices are gaining momentum in power electronic systems such as electric vehicle (EV) charging system, due to their promises to significantly enhance the power density and efficiency. In this dissertation, a GaN-based integrated onboard charger (OBC) and auxiliary power module (APM) is proposed for EVs to ensure high efficiency, high frequency, high power density, and capability of bidirectional operation. The high switching frequency operation enabled by the GaN devices and the integration of OBC and APM bring many unique challenges, which are addressed in this dissertation. An important challenge is the optimal design of high-frequency magnetics for a high-frequency GaN-based power electronic interface. Another challenge is to achieve power flow management among three active ports while minimizing the circulating power. Furthermore, the impact of circuit layout parasitics could significantly deteriorate the system interface, due to the sensitivity of GaN device switching characteristics. In this work, the aforementioned challenges have been addressed. First, a comprehensive analysis of the front-end AC-DC power factor correction stage is presented, covering a detailed magnetic modeling technique to address the high-frequency magnetics challenge. Second, the modeling and control of a three-port DC-DC converter, interfacing the AC-DC stage, high-voltage traction battery and low-voltage battery, are discussed to address the power flow challenge. Advanced control methodologies are developed to realize power flow management while maintaining minimum circulating power and soft switching. Furthermore, a new three-winding high-frequency transformer design with improved power density and efficiency is achieved using a genetic-algorithm-based optimization approach. Finally, a GaN-based integrated charger prototype is developed to validate the proposed theoretical hypothesis. The experimental results showed that the GaN-based charging system has the capability of achieving simultaneous charging (G2B) of both HV and LV batteries with a peak efficiency of 95%

Modelling and digital control of two-phase interleaved coupled-inductor non-isolated DC-DC converters

This thesis focuses on the complete mathematical modelling and digital closed-loop control of two-phase interleaved coupled-inductor non-isolated dc-dc converters. Coupled-inductors have been shown to reduce the cost, size, and weight of high-power magnetic components while increasing efficiency. The complete large-signal model of the coupled-inductor boost converter is presented and compared to the traditional single-phase and two-phase discrete inductor dc-dc converters. The CCM-DCM mode maps are presented and discussed for the coupled-inductor boost converter. Sample analyses of several different CCM and DCM modes of operation are also presented. The different CCM and DCM waveforms are experimentally produced by a 1 kW laboratory prototype. Following on from the large-signal model, the complete small-signal model of the coupledinductor boost converter is presented. The method of solving for the small signal models is discussed, and sample analyses of several different CCM and DCM modes of operation are presented. Calculated and experimental frequency sweeps for several of the CCM and DCM modes of operation are produced and compared to verify the accuracy of the small-signal models. Controllers for the 1 kW prototype are designed from the transfer functions derived from the small-signal models. The control strategy of average-current-mode control is digitally implemented, which uses an outer voltage loop and an inner current loop to eliminate any error between the output and the desired output. The FPGA used in testing is the Altera Cyclone III FPGA. Initially, PI controllers are developed and compared to simulated results. In order to improve the closed-loop performance of the converter, the inner current loop PI controllers are replaced with Type II compensators. Several compensators are designed as examples for a number of CCM and DCM modes of operation. Finally, to increase the stability of the converter, bumpless PI control and forced-output control utilizing the Type II compensators are introduced and implemented

The ATLAS Data Acquisition and High Level Trigger system

This paper describes the data acquisition and high level trigger system of the ATLAS experiment at the Large Hadron Collider at CERN, as deployed during Run 1. Data flow as well as control, configuration and monitoring aspects are addressed. An overview of the functionality of the system and of its performance is presented and design choices are discussed.Facultad de Ciencias Exacta

The ATLAS Data Acquisition and High Level Trigger system

This paper describes the data acquisition and high level trigger system of the ATLAS experiment at the Large Hadron Collider at CERN, as deployed during Run 1. Data flow as well as control, configuration and monitoring aspects are addressed. An overview of the functionality of the system and of its performance is presented and design choices are discussed.Facultad de Ciencias Exacta

Topical Workshop on Electronics for Particle Physics

The purpose of the workshop was to present results and original concepts for electronics research and development relevant to particle physics experiments as well as accelerator and beam instrumentation at future facilities; to review the status of electronics for the LHC experiments; to identify and encourage common efforts for the development of electronics; and to promote information exchange and collaboration in the relevant engineering and physics communities