In recent years, contactless elevator control system has become a hot topic in the industry, among which safety torque cancellation (STO), brake safety control and electronic star sealing are the three most critical technologies.
Safe torque cancellation (STO) means that a power supply capable of causing rotation is not applied to the motor. STO technology is applied to the elevator of AC or DC motor powered by static components. By cutting off the power supply to the motor, the motor can be safely controlled. STO adopts dual-channel circuit architecture, security integrity level reaches SIL3, hardware failure margin is 1, combined with real-time comparison of dual-channel state, to ensure safe and reliable control of motors. STO replaces contactor to control motor, which has the advantages of low running noise, small size and fast response speed.
Brake safety control refers to the use of safety circuit containing electronic components to achieve the safety control of the brake. Brake control and power supply combination, through the safety control of the brake power supply, to achieve safety lock control. The brake control unit adopts the design structure of double actuator, and the independent state monitoring of double actuator makes the control of brake safe and reliable. The safety circuit replaces the contactor control mode of brake, which has the advantages of fast response and long life.
Electronic star sealing refers to the method of using the existing power module of the converter to limit the accidental moving speed of the car by short-connecting the three-phase winding of the motor under the state of safety torque shutdown. The real-time detection of electronic star sealing circuit fully guarantees the pre-diagnosis of loop fault and the effectiveness of star sealing control. Electronic star sealing instead of contactor hardware star sealing has the advantages of smaller size, faster response and more reliable.
Contactless system solution not only promotes the technological innovation of elevator products, but also essentially solves the problems encountered in practical application, which has far-reaching significance.
