The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
An adaptive secondary-side digital control is proposed for the series resonant converter to solve the loss of ZVS under certain input and load conditions, making it a good candidate for MHz 48V voltage regulators (VRs). By means of varying AC equivalent resistance, the output voltage regulation is achieved by controlling the duty cycle of the synchronous MOSFET. An additional control variable has...
Single-phase AC/DC or DC/AC systems inherently subject to harmonic disturbance which is caused by the well-known double line frequency ripple power. This issue can be eased through the installation of bulky electrolytic capacitors in the dc-link, but such passive filtering approach may inevitably lead to low power density and limited system lifetime. An alternative approach is to use active power...
This paper presents the design and optimization of MEMS-microfabricated toroidal inductors targeted for use in integrated power electronics. The process is based on MonteCarlo inductor synthesis, performance evaluation based on analytic inductor models and circuit simulation, and Pareto-optimal filtering. The models and simulation are verified through comparison with magnetic finite element analysis...
This paper introduces the detrimental effects of voltage regulator noise on ΔVBE-based temperature sense circuits. The work began when a significant temperature reporting inaccuracy was observed on a commercial DC-DC power conversion module. In the paper, the observed problem will be discussed, and a Spice model presented which allows the issue to be simulated. The main part of the work, however,...
Cell capacitor energy control of a Modular Multilevel Converter (MMC) is conventionally done by controlling leg current and modulation strategy. In most of literatures, leg current transient is analyzed under an assumption that the DC bus is a stiff DC voltage source. In a real MMC-based HVDC transmission system, however, there's no such virtual stiff DC voltage source and the conventional regulation...
This paper proposes a new 1200V cascaded high voltage IC (HVIC) gate drive circuit for a three-level NPC inverter intelligent power module (IPM). The proposed single-ground IGBT gate driver of the 1200V three-level NPC inverter is based on a bootstrap capacitor charging method and a cascaded 600V HVIC configuration which can dramatically improve its integration for practical use, especially system...
V2 control and its variety named ripple-based control, are popular control schemes in point-of-load Buck converters and Voltage Regulators for microprocessor. This control scheme is elegant when output capacitors with sufficient ESR are employed, such as OSCON capacitors. However, in most cases with small-ESR capacitors, such as ceramic capacitors, instability problem will occur. Up to now, no equivalent...
This paper presents the small-signal modeling and controller design of an isolated Quasi-Switched-Capacitor (QSC) dc/dc converter. The converter serves as an auxiliary power supply in automotive applications, connecting the highvoltage battery and the 14 V power net. It employs a front-stage QSC dc/ac circuit with a 3:1 voltage step-down ratio, and a poststage synchronous-rectifier, current-doubler...
This paper analyzes the stability issue of the Flyback converter which utilizes a second stage LC filtering circuit at its output side. The small signal models of the Flyback converter using second stage filter, in both DCM and CCM, are presented with experimental data collected to verify the theoretical analysis. Finally, guidelines for designing the second stage LC filter are derived to facilitate...
A new equivalent circuit model is presented to predict the small-signal characteristic of current-mode control with DCR current sensing accurately, and a simple auto-tuning method is proposed to solve the issue of time constant mismatch in DCR current sensing. The model shows that the mismatch between the current sensing RC network and the output inductor makes the output impedance deviate away from...
Conventionally, both the primary side and the pickup side need series or shunt capacitor compensation to increase transmission efficiency in a wireless power transfer system. In this paper, a wireless power transfer system with an active resonance circuit is proposed. Comparing the diode based rectifier on the pickup side in traditional wireless power transfer systems, a PWM rectifier is exploited...
This paper presents design and implementation of the phase-shift burst-mode control method for interleaved self-oscillating resonant SEPIC converters for LED lighting applications. The proposed control method utilizes delays in the turn-on and turn-off of the power stage and control circuitry in order to reduce requirements for the comparator in the regulation circuit. The control method is experimentally...
This paper discusses the characteristics of a series-series compensated inductive power transfer system (IPT) with theoretical analysis and experimental results. To maximize system efficiency, two-stage structure, which includes a PFC stage and a resonant DC-DC stage operating in ZVS region, is proposed. One of the major design challenges in implementation of a practical contactless EV charger is...
This paper presents a new power conversion architecture for single-phase grid interface. The proposed architecture is suitable for realizing miniaturized ac-dc converters operating at high frequencies (HF, above 3 MHz) and high power factor, without the need for electrolytic capacitors. It comprises of a line-frequency rectifier, a stack of capacitors, a set of regulating converters, and a power combining...
Three-phase ac systems can be transferred into dq axis, where stability analysis becomes much simpler. In order to apply the stability criterion in AC system, an equivalent DQ admittance model for the ATRU system has been developed in this paper, based on the ABC impedance model in paper [1]. Compared to the literature work, this model has two better features: (1) it is valid in a wide frequency range,...
This paper introduces a flyback-based low-volume modular converter and complementary mixed-signal controller that provide input voltage and output current sharing as well as near optimal transient response. This serial-input paralleloutput switch-mode power supply (SMPS) is well suited for high-step down ratio applications where, compared to a conventionally used multi-phase buck, it requires a smaller...
This paper describes a high-speed protection circuit for IGBTs subjected to hard-switching faults (HSF). The reverse transfer capacitance depends on a collector-emitter voltage and it produces a significant effect on a switching behavior not only under normal conditions but also under HSF conditions. A gate charge characteristic under HSF conditions differs from that under normal turn-on conditions...
Microelectromechanical systems (MEMS) resonators on Si have the potential to replace discrete L-C components in series resonant converters. With acoustic coupling rather than inductive coupling, these MEMS resonators achieve better electromagnetic interference (EMI) performance, and reduce size, weight and volume of the power converter. In this paper, ring shaped piezoelectric microresonators are...
The purpose of this paper is to analyze the impact of interconnection inductances to overvoltage during turn-off transient of silicon carbide (SiC) devices. To understand the switching behavior of the SiC devices, the ringing and overshoots of the voltage caused by the device capacitance and interconnection inductances are considered. Parametric studies are conducted to compare the influences of printed...
A data driven model with thermal effects is proposed for normally-off SiC JFET in this paper. The novel feature of the model is that it saves the trouble of obtaining the physical parameters. Besides, the effect of temperature on SiC JFET performance is taken into account. It is important because the physical parameters on materials and dimensions of a particular SiC JFET device are difficult to be...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.