Harmonic analysis +k 1 -w 1 03.65 1 03.65.-w 1 03.65.Ud 1 03.65.Yz 1 03.70 1 03.70.+k 1 Batteries 1 Circuit faults 1 Decoherence 1 Fault currents 1 Harmonic oscillators 1 Microgrids 1 Oscillators (mechanical) 1 Quantum optics 1 Relays 1 Squeezed state 1 State of charge 1 Ud 1 Yz 1 fault detection 1 harmonic oscillator 1 inverter-based microgrid 1 microgrid protection 1 rate of change of <italic xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">id </italic> (RoCoId) 1 squeezed states 1