Motor flexible brake controlling and zero-speed detecting system based on solid soft starter

Abstract

The invention relates to a motor flexible brake controlling and zero-speed detecting system based on a solid soft starter, comprising a main loop and a control circuit, wherein the main loop comprises a plurality of silicon controlled rectifiers, a contactor KM1 and a high-power diode, wherein every two silicon controlled rectifiers are connected in inverse parallel to form a valve set; an auxiliary normally-closed contact NC1 of the contactor is electrically connected with an SCR1 (Silicon Controlled Rectifier1) in the valve sets and a triggering signal a, and a main normally-open contact KL1 is electrically connected with the output end of valve set and the high-power diode D1; the other end of the high-power diode D1 is electrically connected with the output end of the other valve set; the control circuit comprises a single-chip machine control circuit, a human-computer interface and a peripheral detecting circuit, wherein the single-chip machine control circuit is respectively electrically connected with the human-computer interface and the peripheral detecting circuit; the peripheral detecting circuit is electrically connected with the main loop; and the peripheral detecting circuit is provided with a motor zero-speed detecting circuit for detecting the running state of a motor in a brake state to judge whether the motor stops or not and cutting off the brake output of the soft starter according to the stopping point. The system realizes motor flexible brake control and zero-speed detection on the basis of the hardware through a motor brake controlling program and a motor zero-speed detecting program.

Description

technical field [0001] The invention relates to motor dragging and control technology, that is, a motor zero-speed detection and braking control technology based on a soft starter. Background technique [0002] For example, many industrial machinery such as machine tools need to be equipped with motors as driving power, and the motors need to have the function of quick stop. So far, only some solid-state soft starters have braking functions, and they mainly use "reverse braking". [0003] The so-called "reverse braking" means that when the three-phase AC asynchronous motor brakes, the phase sequence of any two-phase power supply in its input power is changed, so that the rotation direction of the internal magnetic field of the motor changes, that is, the internal magnetic field of the motor is reversed. turn. At this time, a reverse torque is generated between the reverse magnetic field and the rotor, which hinders the forward rotation of the motor rotor and the load, and ...

AI Technical Summary

Problems solved by technology

[0005] The reverse connection braking of the soft starter is simpler than the traditional mechanical braking structure, the braking effect is better, and the failure rate is low. However, the mechanical impact of the braking process of this method is large, the control of the braking process is complicated, and the motor braking process is prone to overturning. Phenomenon

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