Patent ID: 9553540
Date: 2017-01-24
CPC Classifications: G01R,H02M,H02P

Claim:
1. A power converter comprising: a DC link configured to receive a DC supply voltage; a phase leg comprising an upper switching device and a lower switching device coupled across the DC link, wherein a junction between the upper and lower switching devices is configured to be coupled to a load; a current sensor for the phase leg detecting a positive or negative direction of a current flow from the junction to the load; and a gate driver coupled to the phase leg activating the upper switching device according to an upper gate signal and activating the lower switching device according to a lower gate signal in response to pulse-width modulation (PWM) to generate nominal gate signals from a variable duty cycle; wherein when the positive current direction is detected then the upper gate signal has a turn-on time and a turn-off time each shifted by a predetermined offset with respect to the nominal gate signals, and the lower gate signal has a turn-on time delayed with respect to a corresponding turn-off time of the upper gate signal and has a turn-off time advanced with respect to a corresponding turn-on time of the upper gate signal; and wherein when the negative current direction is detected then the lower gate signal has a turn-on time and a turn-off time each shifted by a predetermined offset with respect to the nominal gate signals, and the upper gate signal has a turn-on time delayed with respect to a corresponding turn-off time of the lower gate signal and has a turn-off time advanced with respect to a corresponding turn-on time of the lower gate signal.