Patent ID: 9612998
Date: 2017-04-04
CPC Classifications: G01R,G06F,H02M,H02P

Claim:
1. A method of detecting a fault condition in a power converter having a DC bus, wherein the power converter is configured to transfer power between the DC bus and a motor and wherein the power converter has a shunt resistor selectively connected across the DC bus, the method comprising the steps of: measuring an amplitude of voltage present on the DC bus when there is no power transfer between the DC bus and the motor; verifying that the amplitude of voltage is greater than a first threshold; connecting the shunt resistor across the DC bus when the amplitude of voltage is greater than the first threshold and when there is no power transfer between the DC bus and the motor; measuring the amplitude of voltage present on the DC bus when the shunt resistor is connected across the DC bus; measuring an amplitude of current present on the DC bus when the shunt resistor is connected across the DC bus; and detecting at least one fault condition as a function of the amplitude of at least one of voltage and current present on the DC bus when the shunt resistor is connected across the DC bus.