| 摘要 |
<p>A power conversion device using semiconductor switching elements comprises voltage detection means for detecting the voltage between the collector and emitter of each semiconductor switching element to reduce the switching loss and conduction loss in switching elements. The base current supplied to the switching element is controlled according to the detected collector-emitter voltage. Either the control of the collector-emitter voltage or the control of the regeneration power sent to an external auxiliary power supply from a switching element drive source is carried out for optimum control in consideration of the deviation in hfe among different switching elements, the change in hfe with temperature, and the change in hfe depending on the current flowing in the switching elements. The sum of conduction loss and driving power of the switching elements thus decreases.</p> |
