Quantitative comparison of permanent magnet linear machines for ropeless elevator

Ropeless elevators have developed very quickly in recent years. There are two main drawbacks of the conventional elevators with rope, especially when they are used in skyscrapers of 250-400m high [1]. One problem is that the space occupancy of the total floor space would be more than 30% in buildings over 250m high [2]. Another drawback is that controlling the elevator in tall buildings is difficult due to the mass and vertical vibration of the steel cable. As the key part of ropeless elevator system, linear machine is very suitable due to its little limitation on building height and space requirement [3]. And the permanent magnet linear machines attract more and more attention due to the high torque density and efficiency.