Observer based PWM dead time optimization in automotive DC/DC-converters with synchronous rectifiers

An observer based PWM dead time optimization approach for DC/DC-converters with synchronous rectifiers is introduced. The method is well suited, if optimization of PWM dead times at varying converter bus-voltages is required. In order to minimize effects of uncertainties, disturbances and noise on the estimated state variables, an intrinsic hardware implemented observer is proposed. A two-phase DC/DC-converter prototype for an automotive dual-voltage power-net was developed. The optimization concept was realized in the converter control structure without using additional components. The detection of optimal PWM dead times, increasing efficiency and reduction of voltage transients were shown experimentally.