Overvoltage protection for redundant power supplies
Power supply control system comprising a plurality of power supply units
Parallel power system which includes over voltage protection
ApplicationNo. 11199644 filed on 08/09/2005
US Classes:361/56, Voltage responsive361/57, Current responsive361/91.1, Overvoltage323/272, Parallel connected323/285With plural condition sensing
ExaminersPrimary: Sherry, Michael J.
Assistant: Mai, Thien T
Attorney, Agent or Firm
International ClassesH02H 9/00
AbstractA protection circuit for a parallel power system having at least two parallel coupled voltage regulators is disclosed. The protection circuit includes at least two isolation control circuits, each control circuit being coupled to a respective voltage regulator. Each isolation control circuit includes a current sense circuit for sensing current polarity at an output of the respective voltage regulator, and a controller for automatically isolating the respective voltage regulator when an over-voltage condition exists at an output of the parallel power system and a positive current polarity is sensed at the output of the respective voltage regulator. The at least two isolation control circuits isolate only a voltage regulator having positive current outflow during the over-voltage condition. In one embodiment, each isolation control circuit further includes an over-voltage detection circuit for detecting when the over-voltage condition exists at the output of the parallel power system.