Many microgrids operated for resiliency enhancement purposes have inverter-based resources as their primary source. Although inverters are highly flexible, typically for cost reasons they are designed to provide only relatively low levels of fault current and only for a short time. This creates a common challenge: these techniques will often not work in inverter-based systems, because the typical means for isolating a fault to the smallest possible part of the system rely on high fault currents. More advanced techniques are required to ensure that the entire microgrid system does not “go dark” every time there is a small fault anywhere on the system.
As a greater number of power providers and decision-makers seek inverter-based microgrid solutions, protecting these investments and reducing their risk becomes a crucial part of the project. This presentation will discuss:
a) Types of studies that can be done to identify which methods will work in a given situation and quantify the parameters,
b) Scalability of the techniques,
c) Relative costs of implementation, and
d) Means of testing equipment that will participate in these advanced protection systems, so that the equipment is field-ready when it arrives on-site.