Failure guiding safety principle-based contactor automatic switching control method

Abstract

The invention discloses a failure guiding safety principle-based contactor automatic switching control method. Contactors are connected in series into a main circuit and a standby circuit respectively, and a control circuit is separated from a driving circuit. When the control circuit transmits a signal to the driving circuit, the driving circuit releases a corresponding contactor; and the driving circuit forms interlocking between two contactor driving circuits by adopting diodes and triodes, and when the two contactors do not receive a releasing signal, only a current contactor is kept in an off state, and the other contactor is not switched off. By the method, the separation of a high voltage circuit from a low voltage circuit and the separation of a device with long service life from a quick-wearing device are realized, electromagnetic interference between the high voltage circuit and the low voltage circuit and between the device with the long service life and the quick-wearing device is reduced, potential safety hazards of the circuits are reduced, and simultaneously, maintaining cost and maintaining difficulties are reduced. When a control board fails, a power supply system can maintain an original power supply state, and the software upgrading of the control board may not cause the interrupt of power supply, so higher power supply reliability is achieved.

Description

technical field [0001] The invention belongs to the field of industrial electrics, and in particular relates to a contactor automatic switching control method based on the principle of fault-oriented safety. Background technique [0002] Generally, important equipment is equipped with a main power supply and a backup power supply. Normally, it is powered by the main power supply with high reliability. When the main power supply fails, the main power switch is turned off, and the backup power switch is turned on. This ensures that the power supply of the device is not interrupted. [0003] Since there may be phase and voltage differences between the two power supplies for the equipment, the two power supplies cannot be closed at the same time to prevent the circulation of the two power supplies and damage the power supply system. However, the longer the two switches are turned off at the same time, the longer the power-off time of the equipment, and even cause the equipment ...

AI Technical Summary

Problems solved by technology

[0005] (1) The failure of the board where the control circuit is located may cause the device to power down. At this time, no control signal is sent out, and the drive circuit will release the two contactors for power supply, which will eventually cause the device to power down.

It leads to the expansion of faults, which does not conform to the principle of fault-oriented safety;

[0006] (2) The control board cannot realize online program upgrade

At present, control boards are often controlled by programmable smart devices, and programmable devices often have upgrade needs, but after the software is upgraded, they need to be restarted. When restarting, the smart board cannot send a control signal for the contactor to pull in, which will cause the contactor to loosen. off, the device input is powered off, and online software upgrades cannot be realized

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