Relay protection for microgrids

Are multifunction protective relays a good choice for Microgrid controls?

Multifunction protective relays are an economical choice for microgrid controls because the hardware is commonly required at the point of interface (POI) to the electric power system (EPS) and at each distributed energy resource (DER). The relays at the POI and DER provide mandatory protection and human safety.

What is a microgrid relay?

In smaller microgrids, relays are commonly utilized for control, metering, and protection functions. In larger microgrids, the functionality of the microgrid controls is predominantly performed in one or more centralized controllers.

Can a microgrid provide a fault analysis for different relay types?

This paper presents such analysis for different relay types by considering various fault and generation conditions in a microgrid. Time-domain simulations are used to identify the scenarios where the relays function correctly as well as the problematic conditions, on which future research should focus.

Do microgrid relays perform well in macrogrids?

Although years of operation in macrogrids support these relays, their performance for microgrids is yet to be analyzed. This paper presents such analysis for different relay types by considering various fault and generation conditions in a microgrid.

How to protect a microgrid?

It is important to make sure that the protection schemes can detect and respond to faults inside and outside of the microgrid and maintain coordination between protective devices in both grid-interconnected and grid-isolated modes, and in the presence of varying numbers and types of sources.

Are relay-based controls a cost-effective solution for small Microgrids?

Relay-based controls are a cost-effective solution for smaller microgrids. The additional cost, complexity, and testing of centralized controller-based systems are generally only warranted on large microgrids with more than 10 MW of generation. These large microgrids can include many DERs, loads, and complex topologies.