| 摘要 |
<p>A power conversion system (10) wherein power conversion switching devices (S1-S6) are switched near zero voltage conditions to minimize losses and increase frequencies. Zero voltage conditions are achieved by providing snubber capacitors (Cs1-Cs6) across each switching device (S1-S6) and the active commutation unit (14) to establish a resonance between the snubber capacitors (Cs1-Cs6) and the active commutation unit (14). Zero current switching of the active commutation unit (14) and reduced stress in the power conversion switching devices (S1-S6) is achieved by controlling the switching devices (S1-S6) to establish zero current conditions and a desired snubber voltage for the active commutation unit (14) before the active commutation unit (14) is turned on to establish the resonance. Since zero voltage switching conditions are achieved, the power conversion may be controlled by PWM.</p> |
