A resonant-commutated-link variable-frequency converter

A novel DC-link converter utilizing resonant commutation is presented. Since resonant commutation is accomplished, converter switches are thyristors (SCRs) with lower costs than forced commutated devices. Focus is on the variable-frequency operation of the converter, with potential application in variable-frequency custom power delivery or adjustable-speed motor drives. The converter operates with greater stored energy in the DC link, thus offering current holdup capabilities during a contingency which cannot be attained with a conventional resonant DC-link converter and achieves minimum switching losses without increased conduction losses. Harmonic elimination is achieved by employing sinusoidal pulsewidth modulation (SPWM) control of the converter. Simulation results and experimental validation of the resonant commutation of a low-voltage and low-power laboratory model are discussed. Work in progress and the scope of further work are discussed     

A DSP controlled variable-frequency resonant-commutated converter

Features of a three-phase resonant-commutated variable-frequency converter applicable in a variety of industrial applications are presented. Minimization of switching losses and hence usage of naturally commutated devices as accomplished by resonant commutation of the converter is highlighted. Design and development of the TMS320C30 DSP based controller is described. Strategies developed for switching of converter devices in relation to the resonant-commutated link are discussed. Results from Pspice simulation studies of the converter are presented. Experimental results while the three-phase experimental model of the converter supplied passive loads are enclosed and observations summarized. Comparison of results confirms potential applicability of the converter in adjustable speed drive, induction heating, welding and active filter applications     

RF packaging and passives: design, fabrication, measurement, and validation of package embedded inductors

Design, modeling, and characterization of inductors embedded in a package substrate promising higher quality factor (Q) and lower cost than on-chip inductors is described. In addition to the problem of large conductor losses, on-die inductors with or without magnetic materials consume considerable die area and require the removal of the first-level interconnect bumps beneath them to maintain a reasonably high Q value. Moving inductors to the package eliminates the need for bump array depopulation and, thus, mitigates the potential reliability problems caused by voids in the epoxy underfill between the die and the substrate. Competency developed to design, fabricate, and characterize inductors based on standard organic flip-chip packaging technology is described. Physical design details along with measurement procedures and results are discussed. In addition, modeling techniques for achieving good correlation to measured data are included.