A new current-mode controlled -48 V/100 Amp SMR using isolated semiconductors

The authors describe the development of a 6 kW offline switched-mode rectifier (SMR) which is being manufactured in two versions: three-phase and single-phase. The rectifier uses a full-bridge converter topology with power MOSFET transistors and is current-mode controlled. The unit is convection-cooled and uses only isolated-case power modules which are directly mounted on the heat sink. The rectifier is field-upgradable from a basic unit equipped with essential alarms and plant controls to a surveillance-enhanced rectifier with elaborate diagnostics and commands for the purpose of remote monitoring and control. A well-designed heat sink along with a careful choice of components yields a typical overall efficiency of 90%. It is concluded that the current-mode control technique provides an excellent dynamic performance under fast load variations along with excellent line ripple rejection