Building asynchronous motor starting locked-rotor fault processing circuit

Abstract

The invention discloses a building asynchronous motor starting locked-rotor fault processing circuit comprising an asynchronous motor (1) which is connected with a voltage and current detection circuit (2). The output end of the voltage and current detection circuit (2) is sequentially connected with a direct current blocking and passing capacitor (3), a threshold comparator (4), a charging and discharging circuit module (54), a Schmitt trigger (5), a first AND gate (6) and a fault latching and processing trigger (7), and the first AND gate (6) is provided with a starting timing circuit module (8) connected with the charging and discharging circuit module (54). The output end of the fault latching and processing trigger (7) is connected with an isolation driving circuit (9); the isolation driving circuit (9) is connected with a KM coil (10) connected with the asynchronous motor (1); according to the invention, the locked-rotor fault in the starting stage of the motor can be detected and power-off protection is carried out, so that the operation safety and service life of the asynchronous motor are improved.

Description

technical field [0001] The invention relates to the field of construction electromechanical equipment, in particular to a fault processing circuit for starting and stalling of a construction asynchronous motor. Background technique [0002] As a power source, motors are widely used in the construction industry, such as screening materials, concrete mixing, material transportation, and personnel transportation. Due to the complex working conditions of the motor application and the imperfect protection measures, it is often encountered that the motor rotor is blocked, such as the transmission mechanism on the motor rotor is locked or the speed change gear is blocked due to foreign objects or failures, and the elevator transmission chain is blocked. Dead, the belt of the conveyor is stuck, the fluid medium of the pump is frozen or the sediment is blocked, etc. Once the stall occurs, the current of the motor rises sharply, which is much larger than the rated working current, an...

AI Technical Summary

Problems solved by technology

Due to the complex working conditions of the motor application and the imperfect protection measures, it is often encountered that the motor rotor is blocked, such as the transmission mechanism on the motor rotor is locked, or the transmission gear is blocked due to foreign objects or faults, and the elevator transmission chain is stuck. Dead, the belt of the transmission device is stuck, the fluid medium of the pump is frozen or the mud is blocked, etc.

Once a stall occurs, the current of the motor rises sharply, which is far greater than the rated operating current, and can even reach more than ten times the rated current. The huge current causes a sharp increase in power consumption of the motor, the temperature inside the motor rises rapidly, and the insulation paint of the motor coil is damaged. , resulting in a short circuit inside the motor, further increasing the current of the motor, and even causing a fire in severe cases

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