Search results for "DC-DC converters"
showing 10 items of 10 documents
Architecture of a digital PFM controller for IC implementation
2006
This paper presents a digital controller architecture oriented to IC implementation. The classical digital pulse width modulator (D-PWM), using digital analog converter (DAC), is replaced with a Sigma-Delta (/spl Sigma//spl Delta/) modulator based on pulse frequency modulator (PFM) technique. Results of an investigation from a prototype for DC-DC converter, in terms of simulated and experimental performances, are reported, together with harmonic frequency investigation. The control function design is implemented on a field programmable gate array (FPGA). As a consequence of good agreement between simulated and experimental results, the proposed architecture realizes a digital control loop w…
Dynamic performance evaluation of a non linear digital control technique for multiphase VRMs
2010
Power losses comparison between Silicon Carbide and Silicon devices for an isolated DC-DC converter
2021
In recent years, new efficient power devices have been implemented. Silicon Carbide has replaced silicon as regards the production and the utilization of many devices, such as MOSFETs, diodes, IGBTs and many others. SiC devices are characterized by a low reverse recovery charge, high carrier saturation velocity, by which it is possible to work at high frequency, and high breakdown voltage. Thanks to the great thermal conductivity and the wide bandgap, these devices can operate at high temperature and reach high voltages and currents. What is important to stress is the fact that power losses in SiC devices are lower than the silicon ones. These are the reasons why these devices are utilized …
Digital power conversion system based on a sigma-delta modulator linear model
2005
This paper presents a new linear model for the sigma-delta (/spl Sigma//spl Delta/) modulator, based on modeling the nonlinear quantizer with a linear factor, and its input-to-output transfer function is given. The use of a 1-bit sigma-delta modulator in DC/DC power converter systems permits to implement a complete digital control. Results of an investigation from a prototype for a DC-DC converter are here reported. Using of a field programmable gate array allows implementing a simple variable control function. The modulator output produces a variable-frequency variable duty-ratio signal to control the switching power transistors.
A digital control technique for high-performances DC-DC converters
2008
A comparison of different DC-DC converters for energy storage management in nearly-Zero Energy Buildings
2020
In the recent years, there has been a notable interest towards renewable sources, energy saving and efficiency optimization, in order to reduce the damages brought by fine dust and greenhouse gases in terms of safety, health and environmental protection. In the building sector renewable sources and energy efficiency optimization are leading to a large scale employment of nearly-Zero Energy Buildings (n-ZEBs), meaning that the balance between produced and required energy is negligible. For a proper n-ZEB implementation, a power system architecture has to be accurately designed, according to the existing renewable sources, loads and storage systems. In this paper, an investigation on differen…
Simulation of parasitic effects on Silicon Carbide devices for automotive electric traction
2020
Wide Band Gap (WBG) semiconductors are increasingly addressed towards Electric Vehicle (EV) applications, due to their significant advantages in terms of high-voltage and low-losses performances, suitable for high power applications. Nevertheless, the packaging in WBG devices represents a challenge for designers due to the notable impact that inductive and capacitive parasitic components can bring in high switching frequency regime in terms of noise and power losses. In this paper, a comparison between conventional Silicon (Si) and emerging Silicon-Carbide (SiC) power switching devices is presented. The effects of inductive parasitic effects and switching frequency are investigated in simul…
A new current-mode control for DC/DC converter
2005
Current-sensing is used widely in smart power chips, especially in DC/DC converter for voltage regulator modules (VRM), implemented with interleaved synchronous rectifier buck converters. The interleaved technique main difficulty is due to its current-sharing control between the several modules. Besides, if the used control technique is current-mode type, it is necessary create a ramp signal proportional to current on the inductor. In this paper, a lossless current-sensing method, solving the major disadvantages of the current-mode control and implementing a current-sharing technique, is proposed. This innovative technique is tested in a two-module interleaved buck converter.
A High-Efficiency, Low-Cost Solution for On-Board Power Converters
2012
Wide-input, low-voltage, and high-current applications are addressed. A single-ended isolated topology which improves the power efficiency, reduces both switching and conduction losses, and heavily lowers the system cost is presented. During each switching cycle, the transformer core reset is provided. The traditional tradeoff between the maximum allowable duty-cycle and the reset voltage is avoided and the off-voltage of active switches is clamped to the input voltage. Therefore, the system cost is heavily reduced and the converter is well suited for wide-input applications. Zero-voltage switching is achieved for active switches, and the power efficiency is greatly improved. In the output …
Development of bidirectional dc-dc converters for hybrid power sources - Final Report
2018
A Bidirectional Isolated Full-Bridge Converter was designed, prototyped and tested. The device is intended to interface a Bank of Supercapacitors with a battery-powered bus, in order to boost the capability of supplying large power peaks. The converter was based on the Isolated Dual Active Bridge configuration. When driven by an external control voltage, it is capable of generating in both directions a train of current pulses, with 2kW peak power, for any battery voltage in the range 24-32V and for any supercapacitor voltage in the range 35-70V. Worst-case battery current was 70A. Pulse duration was 100ms with 50% duty cycle and 1 ms rise time.