Low voltage direct current in elevator electrification

The development of low voltage direct current (LVDC) networks is one of the most important ways to make electrical systems increasingly efficient. More efficient power systems are needed to mitigate climate change and promote sustainable development. This thesis examines the applications of the LVDC networks and their benefits for electrical systems. The main goal is to study how LVDC networks can be used in the electrification of elevators and how elevator systems can be made more efficient. The thesis first examines the structures of LVDC networks and their main development targets, as well as the most significant power electronics converters that have enabled the development of the LVDC networks. The LVDC networks have been extensively tested in electrical distribution networks as well as in its applications such as microgrids. As results of the development of LVDC systems, many different network structures have emerged that have allowed the LVDC networks to be utilized in other applications as well. At the end of the thesis, it is examined how LVDC networks can be utilized in smaller electrical systems. The thesis shows that the LVDC networks can be utilized in the electrification of elevators in many ways. As in the electrical distribution networks, the electrification of elevators can be implemented, among other things, with various hybrid LVDC solutions, which especially improve the power transmission capacity of long-distance elevators and reduce elevator construction costs. The elevator electrical system also benefits considerably from the fact that the power supply of the elevator is implemented by the LVDC network. As the number of the LVDC distribution networks increases and LVDC technology evolves, it can be noted that LVDC systems have potential for the elevator electrification