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.
This paper deals with a modular, isolated-output, polyphase, AC/DC converter based on the use of Resistor Emulators (REs). A RE is a DC/DC converter that behaves as a resistor at its input port. The value of this resistor (input impedance) is controlled by the converter duty cycle. In the proposed topology, all the REs are controlled to have the same input impedance, whose value is determined by the...
In this paper, a control method for three single-phase isolated ac-dc converter modules employed to implement an isolated three-phase, three-wire ac-dc converter is presented and its detailed design procedure provided. In the described control the input voltages of the Y-connected single-phase modules with floating common Y point are kept within a safe range by equalizing their input admittances....
Traditionally, DCM/CCM Boundary Boost PFC Converters with current-mode control require line voltage sensing (via a resistor divider) to define the sinusoidal shape of the reference for the inner current loop and a multiplier to adjust the amplitude of this reference to regulate the output voltage. In contrast, using voltage-mode control neither line voltage sensing nor a multiplier is needed. Lower...
Control scheme for TRIAC dimming high PF single-stage LED driver with adaptive bleeder circuit and nonlinear current reference is studied in this paper. The target of the control scheme is to achieve high efficiency and high compatibility to different kinds of TRIAC dimmers. The control scheme includes adaptive bleeder circuit control, operation modes control, non-linear current reference and output...
This work presents a driver for High-Brightness Light-Emitting Diodes (HB-LED) in three-phase grids, which complies with IEC 1000-3-2 Class C requirements, achieves high Power Factor (PF), low Total Harmonic Distortion (THD), as well as, the capability to achieve full dimming while disposing of the bulk capacitor and having galvanic isolation. The HB-LED driver is based on the use of six four-port...
An algorithm based on new circulated current model is proposed to analyze the circulating current in the multiphase LLC converter. First of all, a virtual-open concept is introduced and LLC phases are decoupled from each other, Thus, A circulating current model can be achieved from fundamental harmonic approximation (FHA). Secondly, the ac voltages on the equivalent resistor of different phases are...
The modular multilevel converter (MMC) has become one of the most promising converter technologies for medium/high-power applications, specifically for high-voltage direct current (HVDC) transmission systems. One of the technical challenges associated with the operation and control of the MMC-based system is to precharge the submodule (SM) capacitors to their nominal voltages during the startup process...
A passive impedance matching (PIM) concept is proposed for multi-phase resonant converters application. The new concept can achieve load current sharing between every unit automatically. A passive element such as an inductor or a capacitor is connected in the common branch of the two units (or multi-units), such that several sets of equivalent positive resistors and negative resistors are distributed...
This paper presents a high performance cost-effective medium voltage power switch based on the series-connection of low voltage SiC normally-on JFETs using an innovative approach. A prototype module of the proposed switch is experimentally demonstrated having an on-resistance of 127 milliohm and a blocking voltage above 4,500V at room temperature. The prototype module is capable of very low switching...
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.