Motor stall protection control method

Abstract

The invention discloses a motor stalling protection control method. A stalling monitoring module and a stalling processing module are arranged in a main control program of an AC-DC-AC frequency conversion driver; the stalling monitoring module monitors change of a DC bus voltage, calculates a first-order derivative and a second-order derivative of the DC bus voltage, judges whether stalling occurs or not according to a change trend and obtains a stalling type. After the stalling is discovered, the stalling processing module lowers a heating risk of a motor in a manner of stepwise reducing a current of the motor. Without changing hardware configuration, the stalling monitoring module and the stalling processing module are arranged in the main control program, so that stalling monitoring and processing are realized and heating due to the stalling is effectively controlled.

Description

technical field [0001] The invention relates to a motor stall protection control method. Background technique [0002] When the drive drives the AC motor, it often stalls. In the punch press and press system, the stall phenomenon is particularly prominent, and it will occur frequently when adjusting the mold and changing the target material. [0003] The motor stall situation usually occurs in two states, one is when the motor is started; the other is when the motor is running. The stalled rotor at the start of the motor has the characteristics of zero speed or extremely low speed. If the motor starts, it needs to overcome high torque and inertia. Because the overload capacity of the motor is relatively poor at this time, the heat generation is serious. The situation of stalling during the operation of the motor is quite special. Since the motor already has a certain initial speed, the heat generation of the motor after stalling will be different due to different load cond...

AI Technical Summary

Problems solved by technology

The common solutions are: (1) Increase the size of the module to increase the module capacity in a disguised form. The defect is that the module resources are wasted; (2) Set the upper limit of the current. After reaching the upper limit, the driver will automatically jump to the protection mode to protect the module Its disadvantages are: the working conditions of the motor are more complicated, and the limit value is difficult to determine. If the setting is too high, the module resources will be wasted, and if it is too low, the driver module or the motor will be easily damaged. Moreover, the conventional protection mode is to directly cut off the power of the motor, but this The operation is quite dangerous in the presence of potential energy loads and other mechanical potential energy, and for working conditions without mechanical potential energy, there is also a potential hidden danger of damage to system accessories if the power is directly cut off