Patent ID: 8395873

Claim:
A method for fault detection in a direct current (DC) electrical system by a solid state power controller (SSPC), the SSPC comprising a high bandwidth fault detector and a low bandwidth fault detector, the method comprising: detecting a possible fault by the high bandwidth fault detector, wherein the high bandwidth fault detector detects the possible fault based on information from an output current sensor that is located between a power switch of the SSPC and an SSPC output, the SSPC output being connected to a DC load, and the power switch being located between the SSPC output and a DC power source input of the SSPC; placing the power switch of the SSPC in saturation at a predetermined current limit based on the possible fault; determining whether the possible fault is a confirmed fault by the low bandwidth fault detector, wherein the low bandwidth fault detector determines whether the possible fault is the confirmed fault based on information from each of an input voltage sensor configured to determine a voltage at the DC power source input, an output voltage sensor configured to determine a voltage at the SSPC output, a temperature sensor of the SSPC, and the output current sensor; in the event the possible fault is determined to be the confirmed fault, turning off the power switch; and in the event the possible fault is determined not to be the confirmed fault, turning on the power switch at a minimum on-resistance.