Authors
Antra Kalnbalkite
Riga Technical University, Faculty of Electrical and Environmental Engineering, Institute of Energy Systems and Environment, Riga, Latvia
Jelena Pubule
Riga Technical University, Faculty of Electrical and Environmental Engineering, Institute of Energy Systems and Environment, Riga, Latvia
Dagnija Blumberga
Riga Technical University, Faculty of Electrical and Environmental Engineering, Institute of Energy Systems and Environment, Riga, Latvia