Fault Detection Apparatus and Method

A method comprising:

• enabling a current source to charge a terminal connected to a voltage sense line of a power conversion system;
• after a predetermined period, sampling a voltage at the terminal;
• comparing the voltage at the terminal with a predetermined threshold voltage;
• and
• reporting a sense line disconnection fault upon finding that the voltage on the terminal is greater than the predetermined threshold voltage.

A power conversion system comprising:

• a plurality of power converters connected in parallel connected between an input voltage bus and an output voltage bus;
• and
• a controller comprising:
• a current source coupled to a bias voltage bus;
• a plurality of positive voltage detection control switches coupled to a first terminal connected to a positive voltage sense line of a power conversion system;
• a plurality of negative voltage detection control switches coupled to a second terminal connected to a negative voltage sense line of the power conversion system;
• and
• a fault detection comparator comprising:
• a non-inverting input coupled to the first terminal through one of the plurality of positive voltage detection control switches, and coupled to the second terminal through one of the plurality of negative voltage detection control switches;
• an inverting input configured to receive a predetermined fault detection threshold voltage;
• and
• an output configured to generate a fault detection signal indicating whether a sense line disconnection fault occurs.