The elevator door operator is a mechanism responsible for opening and closing the car door of the elevator hall. When it receives the elevator door opening and closing signals, the elevator door machine controls the door opening motor through its own control system to convert the torque generated by the motor into a specific direction Force to close or open the door. When the preventing closing force is greater than 150N, the door machine automatically stops closing the door and opens the door in the reverse direction to provide a certain degree of door closing protection. The technology of door operator has gone through the development of mechanical door operator, frequency conversion door operator and synchronous permanent magnet door operator.
The old-fashioned elevator door machine is an AC asynchronous variable frequency door machine, usually referred to as a variable frequency door machine. Its composition is mainly divided into three parts: variable frequency door machine control system, AC asynchronous motor and mechanical system; elevator variable frequency door machine has two motion control methods : "Speed switch control mode", "Encoder control mode"; "Speed switch control mode" cannot detect the direction, position and speed of the car door, and can only use position and speed open-loop control, resulting in relatively poor control accuracy. The smoothness of the door machine movement process is not very good, so "encoder control mode" is often used.
With the progress of society and the development of technology, permanent magnet synchronous door operators have appeared. Compared with the frequency conversion door machine, the permanent magnet synchronous door machine upgrades the AC asynchronous motor to the synchronous permanent magnet motor. Permanent magnet is a method of motor excitation, and frequency conversion is a control method of motor variable speed. In other words, the frequency conversion door machine emphasizes that the door machine control part is frequency conversion control, while the permanent magnet synchronous door machine emphasizes that the door machine motor is a permanent magnet motor.
The use of synchronous permanent magnet motor can well solve the problems of the frequency conversion door machine, so now the synchronous permanent magnet door machine has gradually replaced the frequency conversion door machine.