Hybrid electric vehicle power-up sequencing with VVC test

摘要

A method for operating a hybrid electric vehicle having a variable voltage converter (VVC) includes commanding a first voltage across a VVC in response to a signal requesting a VVC test, continuously monitoring a first VVC voltage difference over a first calibratable time period, and generating a diagnostic signal if the first voltage difference exceeds a first calibratable threshold for the duration of a first calibratable time period. The method further includes, in response to the first voltage difference dropping below the first calibratable threshold, commanding a second voltage across the VVC, continuously monitoring a second VVC voltage difference over a second calibratable time period, generating a diagnostic signal if the second voltage difference exceeds a second calibratable threshold for the duration of a second calibratable time period, and signaling a test pass in response to the second voltage difference dropping below the second calibratable threshold.

主权项

1. A method for operating a vehicle system comprising:
isolating a variable voltage converter (VVC) from at least one electric machine; commanding a first voltage exceeding battery voltage across the VVC in response to a start request, and a second voltage equal to the battery voltage across the VVC in response to a first difference between the first voltage and measured VVC voltage falling below a threshold; and generating a diagnostic signal if the first or a second difference between the second voltage and measured VVC voltage exceed respective thresholds for respective time periods; signaling a test pass when the second difference falls below the respective second threshold.