公开(公告)号：US09653987B2

公开(公告)日：2017-05-16

申请号：US14995722

申请日：2016-01-14

Applicant: DELTA ELECTRONICS, INC.

Inventor： Te-Wei Yuan ,  Yu-Ling Lee ,  Yi-Kai Chou ,  Bo-Jheng Lin

IPC: H02M1/36 ,  H02M1/32 ,  H02M5/42 ,  H02H7/122 ,  H02H3/05 ,  H02H9/00

CPC classification number: H02M1/36 ,  H02H3/05 ,  H02H7/122 ,  H02H9/002 ,  H02M1/32 ,  H02M5/42

Abstract: A method for detecting failure of soft start includes: connecting a variable frequency device to a load; detecting an energy storage unit at a first voltage level; generating an output current to the load; detecting the energy storage unit changed from the first voltage level into a second voltage level; generating a reference voltage value according to the output current and determining whether a voltage difference value between the first voltage level and the second voltage level is larger than the reference voltage value; determining whether a voltage peak-to-peak value of the energy storage unit is smaller than a set value by the controller if the voltage difference value is larger than the reference voltage value; and controlling the inverter circuit to stop outputting the output current to the load if the voltage peak-to-peak value is smaller than the set value.