Modeling and quantification of the energy saving potential by using variable speed drives for electric motors at constant load operation

Inhalt:
Variable speed drives (VSDs) for electric motors in industrial applications offer a high energy saving potential in applications with a variable load cycle. Regarding electric motors with a constant load profile, VSDs don't seem to be beneficial for the energy efficiency due to the unavoidable additional losses in the VSD [1]. However, further calculations show that the installation of variable speed drives in units with fixed speed and constant operation points allow more freedom in the system selection process as well as better dimensioning to the required operating point. This results in an increase in the system energy efficiency and thus also an energy saving potential. This is quantified for the European market. First, a clustering and overview of the European pump and fan market is presented. Then, a model that considers different energy efficiency effects is implemented and explained. With the model and the market situation, the total energy saving potential, by implementing VSDs is calculated for the different pump and fan applications. The final energy saving potential results in 19.6 TWh annually, which corresponds to 4.05% of the electricity consumption of pumps and fans. At the end of the paper an interpretation and classification of the calculated results is given.