Energy industries & utilities Technology: general issues 25 History of engineering & technology 15 power electronics 5 renewable energy 5 electric vehicle 4 particle swarm optimization 4 power quality 4 5G 3 antenna array 3 battery 3 demand response 3 energy efficiency 3 energy harvesting 3 multilevel inverter 3 simulation 3 smart grid 3 smartphone 3 DC/AC converter 2 GaN 2 Internet of Things 2 Internet of Things (IoT) 2 IoT 2 PV systems 2 SAR 2 artificial intelligence 2 artificial neural network 2 capacitors 2 clustering 2 compensation 2