Search results for "boost"
showing 10 items of 169 documents
An improved Flyback converter
2009
This paper presents a modified Flyback converter able to operate with higher efficiency and smaller size, overcoming most of the conventional flyback converter drawbacks, and also keeping its low cost and simplicity. In particular, the proposed converter allows the mosfet off voltage to be reduced and clamped to the input, thus recovering the transformer leakage energy. As a consequence, the duty cycle can be extended to unity, thus reducing the voltage stress across the output rectifier, and lowering both the magnetizing inductance and the transformer bias current values. In addition, due to the auxiliary mosfet, the magnetizing current can become negative, eliminating the discontinuous co…
Small-Signal Modeling of a Controlled Transformer Parallel Regulator as a Multiple Output Converter High Efficient Post-Regulator
2004
This paper presents a post-regulator based on the use of a controlled transformer, which adds or subtracts an additional voltage to the output filter of a converter in order to regulate its output voltage. So, their actuation is complementary to that of more known post-regulators, such as the magnetic amplifier (magamp) and synchronous switch post-regulator (SSPR), because the regulation is achieved by controlling the voltage across the filter inductor instead of its charge time. Besides, the post-regulator processes the power in parallel to the one flowing from input to output and only handles a percentage of it. The post-regulation by controlled transformer is suitable of being employed i…
Bidirectional high-power high-efficiency non-isolated step-up DC-DC converter
2006
This paper presents the results of a high-efficiency high-power (5kW) non-isolated bidirectional DC-DC converter. High efficiency, high stability and simplicity are the main goals, and no galvanic isolation is required. The proposed topology is a new BOOST converter with output filter where input and output inductors are coupled together which can be designed to be a minimum phase system. This topology provides therefore input and output current filtering, reducing noise and need of additional filters. Its bidirectionality reduces mass in many applications like in charge/discharge subsystems and lowers cost and component count. This converter is useful with any system that needs backup batt…
A high-efficiency regulation technique for a zero-voltage zero-current power switching converter
1998
This paper describes the application of a new regulation technique to a resonant converter that features zero-voltage (ZV) and zero-current (ZC) switching and works at constant frequency and duty cycle. The regulator utilizes the concept of regulating only a percentage of the total power in a bidirectional manner, thus allowing the converter to be optimized for both mass and efficiency. The proposed regulation technique has a wide range of applicability to almost all types of power converters or inverters that utilize a transformer to produce an isolated output. By using the concept of addition or subtraction of AC voltages, a fully regulated output voltage is achieved. The resultant effect…
Identification and Robust Control of a Quadratic DC/DC Boost Converter by Hammerstein Model
2015
This paper deals with the theoretical framework definition and the experimental application of the Hammerstein (HM) identification and related robust control technique to a quadratic dc/dc single-switch boost (Q-boost) converter. A set of fourth-order transfer functions (TFs) has been identified with the Hammerstein approach, on the basis of a pseudorandom-binary-sequence (PRBS) excitation signal. The set of identified TFs has been then used to design a suitable robust control technique, able to properly deal with the converter parameter uncertainty and load variations. The proposed approach has been tested in numerical simulation and validated experimentally on a suitably developed test se…
High-Efficiency Regulation Method for a Zero-Current and Zero-Voltage Current-Fed Push–Pull Converter
2011
A new high-efficiency regulation method for a zero-current and zero-voltage current-fed push-pull converter is presented. The method proposed is based on the use of a controlled transformer as a post-regulator, which adds or subtracts an additional voltage to the output filter of the converter. An auxiliary regulator, which only handles a percentage of the output power, controls this transformer, and therefore, results in much higher efficiency than a normal preregulator would have. The novelty of the presented converter is that regulation is achieved without affecting the zero-voltage and zero-current switching in any working conditions. Small- and large-signal models of the converter have…
Dynamic modelling of a quadratic DC/DC single-switch boost converter
2017
This manuscript proposes the analysis of a Quadratic Boost Converter (QBC) transformer-less single switch typology. The state space average dynamic model and a constrained state space average model taking into account the mono-directional components of the converter (diodes, switches) have been analyzed. The static gain expression taking into consideration the parasitic elements of the converter and the small-signal transfer function of the QBC typology under study has been obtained. A sensitivity analysis has shown a high variation of the gain versus duty-cycle and of the derivative gain versus parasitic parameters of the converter in the range of the duty-cycle from 0.6 to 0.8 which is ra…
An efficient data model for energy prediction using wireless sensors
2019
International audience; Energy prediction is in high importance for smart homes and smart cities, since it helps reduce power consumption and provides better energy and cost savings. Many algorithms have been used for predicting energy consumption using data collected from Internet of Things (IoT) devices and wireless sensors. In this paper, we propose a system based on Multilayer Perceptron (MLP) to predict energy consumption of a building using collected information (e.g., light energy, day of the week, humidity, temperature, etc.) from a Wireless Sensor Network (WSN). We compare our system against four other classification algorithms, namely: Linear Regression (LR), Support Vector Machin…
Sliding Mode Control of Quadratic Boost Converters Based on Min-Type Control Strategy
2023
The paper deals with the control of a quadratic boost converter supplied by low-voltage energy sources, such as photovoltaic panels, fuel cells, or batteries. The control scheme consists of two control loops. A min-type controller governs the inner loop to force the current state of the nominal model to converge in a neighborhood of the equilibrium state. The external loop processes the output tracking error using an integrator, and it allows reconfiguring the converter's working point by changing the equilibrium state given in the input to the internal loop. This configuration assures both zero tracking error of the output voltage and robustness against load and input voltage variations an…
Complementary frailty and mortality prediction models on older patients as a tool for assessing palliative care needs.
2021
Background: Palliative care (PC) has demonstrated benefits for life-limiting illnesses. Cancer patients have mainly accessed these services, but there is growing consensus about the importance of promoting access for patients with non-malignant disease. Bad survival prognosis and patient9s frailty are usual dimensions to decide PC inclusion. Objectives: The main aim of this work is to design and evaluate three quantitative models based on machine learning approaches to predict frailty and mortality on older patients in the context of supporting palliative care decision making: one-year mortality, survival regression and one-year frailty classification. Methods: The dataset used in this stud…