A constant torque starting and overload intelligent protection method and device for a DC motor

Abstract

The invention relates to the technical field of motor drive and control, in particular to an intelligent protection method and device for constant torque starting and overloading of a separately excited or permanent magnet direct current motor. The device comprises a current closed-loop adjusting unit, a pulse width adjusting unit and a control unit. According to the protection method, intelligentprotection of constant torque starting control and overloading of the direct current motor is realized through motor working current closed-loop detection, a PI adjustor, a PWM variable voltage control technology and a current square attenuation algorithm. The motor is safely started at the maximum speed in an electric drive process, and the motor is scientifically and reasonably protected when the motor is instantaneously overloaded due to load disturbance in a steady-state operation process, so that the working efficiency and the performance of the motor and the robustness of an electric drive system are improved as much as possible on the premise of ensuring safe application of the motor.

Description

technical field [0001] The invention relates to the technical field of motor drive and control, in particular to a constant torque starting and overload intelligent protection method and device for separately excited or permanent magnet DC motors. Background technique [0002] In industrial and agricultural production, a large number of large and medium-sized electric motors are used as prime movers to drive various production machinery and equipment. In the field of automation, various small control motors are widely used as detection, amplification and execution components. As an important branch of the motor field, DC motors have been widely used in modern life due to their good speed regulation performance, wide speed regulation range, large torque and good starting characteristics. [0003] In the process of electric dragging, DC motors often need to be started. The basic requirement for optimal starting is that the starting torque be as large as possible to shorten th...

AI Technical Summary

Problems solved by technology

However, under normal circumstances, when there is an instantaneous overload, although the impact current is large, it should not be shut down due to the short duration, or the overload impact current has not reached the set threshold, but due to the long duration, timely protection and shutdown should be performed

It can be seen that conventional fixed threshold protection measures aimed at the above contradictions will inevitably cause the motor to reduce the robustness of the drag system due to frequent protection actions or burn the motor due to untimely protection.

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