https://repositorio.ufms.br/handle/123456789/60 2026-04-16T22:12:28Z https://repositorio.ufms.br/handle/123456789/14239 Título: Controle da Tensão ou Corrente de Saída por Meio da Estimativa de Parâmetros em Sistema de Transferência de Energia Sem Fio Com Topologia Duplo-LCC Abstract: Wireless Power Transfer (WPT) has emerged as a strategic technology of iinnovation, with strong potential impact on applications such as electric vehicle charging, micromobility systems, and portable electronic devices. Advances in efficient and robust WPT solutions play an important role in promoting sustainable mobility and supporting technological development. In Wireless Power Transfer Systems (WPTS), variations in the load connected to a receiver can cause instability in the waveforms of output voltage and current due to their sensitivity to changes in load impedance. To overcome such drawbacks, this paper presents a control scheme for regulating voltage and current at the output of a WPTS system with the double LCC topology, employing concentric solenoidal coils. The main contribution of this work lies in the development of a control strategy based on the estimation of the equivalent load impedance and the output voltage at the secondary side, under the assumption that the coupling coefficient of the concentric coils remains close to its design value during operation. As a result, the control system relies solely on measurements at the primary side, eliminating the need for communication between the primary and secondary sides of the system. The proposed method is based on estimating secondary-side parameters while assuming that the coupling coefficient of the concentric coils remains close to its design value during operation. The methodology begins with the mathematical modeling of the primary and secondary resonant circuits. By measuring the input voltage and current, the system estimates the load impedance, which is then used to derive the expected output voltage and a reference for the input voltage. To maintain a stable output, the system dynamically adjusts the input voltage, ensuring that it aligns with the theoretical reference value. Analytical calculations and simulations were performed using the MATLAB®/Simulink® platform to validate the proposed approach. Simulations confirmed the theoretical predictions for a wireless system operating at 120 kHz with a power transfer of 100 W. The results demonstrated that the load voltage remains stable at 32 V, even under varying load conditions, while the output current remains at 3 A despite fluctuations in battery voltage. Tipo: Dissertação 2025-01-01T00:00:00Z https://repositorio.ufms.br/handle/123456789/12712 Título: Método para elaboração de estudos de proteção elétrica em unidades consumidoras com geração distribuída Abstract: Medium-voltage grids with distributed photovoltaic generation (DG-PV) present additional challenges to protection coordination and selectivity due to operational variability and the characteristics of inverter contributions to fault currents. This work proposes a systematic method, supported by a computational tool, for conducting electrical protection studies in consumer units with DG-PV. The methodology is applied in a case study at the Sector 01 substation of the Federal University of Mato Grosso do Sul (UFMS) in Campo Grande, MS, encompassing eight distinct operating scenarios: heavy and light loads, without DG, and with DG operating at maximum, medium, and minimum capacity. Simulations were performed in the Simulink® environment, allowing evaluation of protection behavior under different load and generation conditions. The results indicate that the short-circuit current detected by the substation relay remains essentially constant across scenarios, demonstrating the robustness of the method and confirming its applicability for verifying selectivity and defining protection settings in environments with distributed photovoltaic generation. Furthermore, the approach provides a reproducible procedure, contributing to engineering practice and technical documentation of protection studies in consumer units. Keywords: Protection; Coordination; Selectivity; Distributed Generation; Photovoltaic Energy. Tipo: Dissertação 2025-01-01T00:00:00Z https://repositorio.ufms.br/handle/123456789/12403 Título: Conversores Bidirecionais como Infraestrutura para o Carregamento Rápido e Off-Board de Veículos Elétricos Abstract: The use of electric vehicles has expanded. With that in mind, proper charging is key to assist in the evolution of this technology, with fast charging being a differential in day use, where bidirectional power flow can be especially relevant. As such, this work has as its main goal to study and simulate DC-DC and AC-DC power converters for fast-charging of an Electric Vehicle based on Tesla’s Cybertruck model. The simulation employs parallelism and control to simulate the battery charging strategy. As a result, there were multiple current waveforms from both types of converters with parallelism in each of them, meaning higher power demands can be obtained with a single central control scheme, reducing individual power requirements for each converter cell, meaning the cost and volume for the components can be lowered. It was possible to obtain close to 254 kW from 4 NPC VSI connected to the grid, all using the adc-dq0 transformation rule with an SRF-PLL. For the Double-Active-Bridge, 4 converters generated 32kW of power each using a Single-Phase-Shift strategy. This work then concludes that central control parallelism is a valid strategy to supply an EV battery, and in future works, be implemented to reach even higher power standards. Tipo: Dissertação 2025-01-01T00:00:00Z https://repositorio.ufms.br/handle/123456789/11713 Título: MODELOS DE PREDIÇÃO E ANÁLISE DE SENSIBILIDADE UTILIZANDO REDES NEURAIS ARTIFICIAIS E MODELOS ESTATÍSTICOS PARA TOPOLOGIAS HÍBRIDAS DE TRANSFERÊNCIA DE ENERGIA SEM FIO Abstract: This work presents a parametric sensitivity comparative analysis between Double LCC and LCC-S topologies for Wireless Power Transfer (WPT) systems, while developing and evaluating secondary circuit parameter estimation methods using regression techniques and artificial neural networks. The study employs the Monte Carlo method to generate a sample space considering typical tolerances of commercial components, enabling the assessment of parametric variations' impact on system performance. The sensitivity analysis revealed that the coupling factor and main coils are the most influential elements in both topologies' performance, with LCC-S being more robust to parametric variations in terms of output current stability and more sensitive regarding other voltage and current stresses. For secondary parameter estimation, different techniques were implemented and compared, including Radial Basis Function Neural Network (RBF), Principal Component Regression (PCR), Ridge Regression, Kernel Regression, and Partial Least Squares Regression (PLS). Results demonstrate that all techniques can estimate secondary parameters using only primary circuit measurements, with PLS showing superior performance in dimensionality reduction and estimation accuracy. RBF demonstrated excellent capability in coupling factor estimation, while Ridge regression presented a good balance between complexity and precision. The developed techniques can be applied in adaptive control systems, contributing to the development of more efficient and reliable WPT systems. Keywords: Wireless Power Transfer, Sensitivity Analysis, Parameter Estimation, Machine Learning, Hybrid Topologies. Tipo: Dissertação 2025-01-01T00:00:00Z