Abstract: VVVF-applied technique is the main developing direction of hydraulic elevators, and it provides an efficient way to reduce the large energy consumption of hydraulic elevators. The energy saving principle of VVVF controlled hydraulic elevators is studied. The experimental power consumption characteristics of elevator hydraulic circuits are obtained. Compared with the conventional valve controlled hydraulic elevator under the same working conditions, the VVVF controlled one has higher efficiency, lower energy consumption. VVVF technique also has a broad application to other vertically moved mechanism driven by hydraulic power.

Key words: Hydraulic elevators Energy consumption, VVVF drive