Direct current motor control device and safe starting method thereof

Abstract

The invention discloses a direct current motor control device and a direct-current-motor safe starting method. A core processing unit outputs a first PWM waveform signal according to a closed loop feedback signal and a motor starting operation signal so as to drive an IGBT driving loop. The IGBT driving loop acquires the first PWM waveform signal, amplifies the first PWM waveform signal and outputs a second PWM waveform signal so as to drive an IGBT module. The IGBT module acquires the second PWM waveform signal and outputs a motor control signal according to the second PWM waveform signal so as to drive a motor control unit. The motor control unit acquires the motor control signal and adjusts a starting current value of a direct current motor according to the motor control signal. In the invention, in a safe current range of the direct current motor, starting and stopping are realized, and a problem that a starting current of a direct current contactor which controls a switching process is too large is solved.

Description

[0001] Technical field [0002] The invention belongs to the technical field of DC motor control, and specifically relates to a DC motor control device and a DC motor safe starting method. Background technique [0003] The DC motor has a large starting current when starting, and this characteristic is very significant. According to statistical calculations, the maximum impact current can reach 15-20 times the rated current. The starting current of the DC motor, which is much higher than the rated current, causes severe current and mechanical shocks to the DC motor itself. In order to avoid potential safety hazards caused by the starting current, the armature circuit series resistance is used as the starting method of the DC motor in places such as thermal power plants. The above-mentioned startup methods have defects and hidden dangers, which are mainly reflected in the following aspects. [0004] First, it cannot completely solve the problem of large inrush current during the...

AI Technical Summary

Problems solved by technology

[0004] First, it cannot completely solve the problem of large inrush current during the starting process of the DC motor

During the starting process, the starting current of the DC motor is still several times higher than its rated current, and the motor may still be damaged due to excessive starting current

[0005] Second, the control loop is composed of multiple large-capacity DC contactors, intermediate relays, and time relays. The control method is complicated and there are many links, resulting in a high failure rate and maintenance workload, and it is inconvenient to repair and maintain.

[0006] Third, during the start-up process, any level of resistance switching will directly lead to abnormal operation of the DC motor, serious heating of the resistance, and overload of the motor, which poses a threat to the normal operation of the electrical secondary circuit. In the event of an accident, the relevant switch will refuse to trip, further Extending the scope and severity of incidents

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