A new digital relay for dispersed storage and generation (DSG) units (power systems)

A dispersed storage and generation system consists of both a source of energy for conversion to electricity and a means to interconnect this unit to the electric utility system. Most dispersed generators connected to the utility distribution system are less than 5 MW. A new emerging problem arises when a utility circuit breaker is opened while a capacitor-bank and load is energized very near a dispersed storage and generation unit. A new resonance-detecting relay will be developed that has the ability to trip if dangerously high off-nominal frequency voltages are produced at the capacitor-bank or load during this condition (capacitor-excitation).