ANN	Artificial neural network
AD	Arc discharge
BA	Bat algorithm
BP	Back-propagation
BPNN	Back-propagation neural network
CS	Cuckoo search
CVA	Common vector approach
D${}_{op}$	Disruption operator
DADDNN	Dynamic Adam and dropout-based deep neural network
DBN	Deep belief network
DGA	Dissolved gas analysis
GA	Genetic algorithm
GWO	Gray wolf optimization
IEC	International electrotechnical commission
ISSA	Improved salp swarm algorithm
KNN	K-nearest neighbor
LT	Low temperature and overheating
MLP	Multi-layer perceptron
MSE	Mean square error
MVO	Multi-verse optimizer
PD	Partial discharge
PNN	Probabilistic neural network
PSC	Power supply companies
PSO	Particle swarm optimization
SCA	Sine cosine algorithm;
SD	Standard deviation
SOA	Seagull optimization algorithm
SSA	Salp swarm algorithm
SVM	Support vector machine
$\sigma$	Smoothing factor