Fault detection and location in nested microgrids

A method for detecting and isolating a fault condition in a microgrid comprising:

• operating a plurality of switching devices coupled between a plurality of line segments with a network controller;
• receiving measurements from the plurality of switching devices with the network controller;
• determining a fault is occurring within the microgrid using the measurements with the network controller;
• assigning a topology classification to each of the plurality of line segments based on whether a load or a distributed energy resource (DER) is coupled to the line segment;
• assigning a proximity classification to said each of the plurality of line segments based on whether a fault current may flow through the line segment in one direction or two directions;
• determining the location of the fault condition using the topology classifications and the proximity classifications of the plurality of line segments;
• and
• isolating the location of the fault in response to determining the location of the fault condition with a portion of the plurality of switching devices.

A network controller comprising:

• an input/output device structured to communicate with a plurality of switching devices of a microgrid including a distribution line divided into a plurality of line segments by the plurality of switching devices operatively coupled to the distribution line;
• a microprocessor-based processing device;
• and
• a non-transitory memory device structured to store data received with the input/output device and instructions configured to perform the following functions when executed by the processing device:
• receive measurements from the plurality of switching devices,
• determine a fault is occurring within the microgrid using the measurements,
• assign a topology classification to each of the plurality of line segments based on whether a load or a distributed energy resource (DER) is coupled to the line segment,
• assign a proximity classification to said each of the plurality of line segments based on whether a fault current may flow through the line segment in one direction or two directions,
• determine the location of a fault condition using the topology classifications and the topology classifications of the plurality of line segments, and
• isolate the location of the fault in response to determining the location of the fault condition by transmitting an open command to a portion of the plurality of switching devices.