Pulse width- and frequency modulated DC/DC converter for hybrid- and electrical vehicles

Inhalt:
An increasingly significant part of hybrid- and electric vehicles are DC/DC-converter which couples the traction battery with the DC-link of the inverter. The chosen circuit is a multiple two-quadrant transducer topology. Each half bridge is phase shifted to the other half bridges. Due to this the separate phase currents are phase shifted, too. By the superposition of the individual currents, the total current has a less ripple. In opposite to a conventional pulse width modulation, a combination between frequency- and pulse width modulation is used. The frequency controls the current between the “continuous current mode” and the “discontinuous current mode”. By operation in this work load, a zero current switching is realized, which decreases the “switch on” losses.