APS	adaptive protection scheme
BR	backup relay
CTI	coordination time interval
DG	distributed generation
ER	electromechanical relay
GA	genetic algorithm
GOOSE	generic object-oriented substation event
IED	intelligent electronic devices
MINLP	mixed-integer nonlinear programming
MPU	microprocessor unit
PMU	phase measurement units
PR	primary relay
PSM	plug setting multiplier
PV	photovoltaic
$T_r$	smart sensor operating time
TDS	time-dial setting
S_i	ith smart sensor