Proactive relay and relay driver failure identification mechanism and microgrid interconnect device including the same

A relay and relay driver failure identification mechanism for use in a microgrid interconnect device (MID) having a control circuit, a relay couplable to a utility grid and distributed energy resources (DERs), a relay driver circuit structured to actuate the relay to connect or disconnect the DERs from the grid, the relay driver, the relay and the control circuit forming a relay driver feedback loop, the relay and relay driver failure identification mechanism comprising:

• a metal-oxide-semiconductor field-effect transistor (MOSFET) connected to the relay driver and the control circuit, the MOSFET structured to set a test overcurrent threshold, interrupt the relay driver feedback loop and inject a test fault to the relay driver;
• an overcurrent limit resister connected between the relay driver and a drain of the MOSFET and structured to limit current flowing through relay driver to a coil of the relay;
• and
• a pull-up resistor structured to pull a gate of the MOSFET high to keep the MOSFET high during normal operating conditions,
• wherein the control circuit receives relay state information including a relay driver fault feedback signal from the relay driver, cause the relay and relay driver failure identification mechanism to perform the fault test and determine that the relay driver fault feedback signal is accurate based on fault test results.