Cold-end overcurrent-protection driving circuit based on pulse drive and motor driving circuit

Abstract

The invention discloses a cold-end overcurrent-protection driving circuit based on pulse drive. The driving circuit is characterized in that the input ends of a pulse front edge split circuit 1 and a circuit level transferring circuit 2 both receive external pulse control signals, a voltage reference circuit 3 is connected with the input end of the pulse front edge split circuit 1 and a first input end of a comparing unit 5 through a resistor 7, the output end of the comparing unit 5 is connected to the input end of a power unit 6, one end of a feedback unit 4 is connected to the output end of the power unit 6 capable of controlling a loaded cold end, and the other end of the feedback unit 4 is connected to a second input end of the comparing unit 5 and the output end of the pulse level transferring circuit 2, wherein the comparing unit 5, the power unit 6 and the feedback unit 4 form a bistable power-mode trigger, and under the control of input pulses, the power-mode trigger is stable in a reset state where the power unit is powered off or in a bit state where the power unit is powered on; when the power unit 6 outputs overcurrent, the power-mode trigger switches to be in the reset sate where the power unit 6 is powered off and locks to protect itself.

Description

technical field [0001] The invention belongs to the technical field of motor control, and relates to a cold junction overcurrent protection drive circuit and a motor drive circuit based on pulse drive. Background technique [0002] Motors are widely used in industrial production, agriculture, transportation, mining, aerospace and other industries. [0003] Among them, the pulse modulation motor powered by DC power supply has developed rapidly due to its advantages of high control precision, energy saving, and large torque. Such as a variety of permanent magnet motors, switched reluctance motors, etc., all use pulse modulation control circuits to regulate their speed, torque, and power. Almost every such motor needs to be equipped with a controller, and the circuit structure adopted by the controller directly determines the operation performance and safety reliability of the controlled motor. [0004] Therefore, some motor controllers use a drive circuit with an over-curren...

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Problems solved by technology

[0006] 1. For the main circuit current sampling method, since the detected main circuit current of the motor bus often lags behind the short circuit / over current moment of the phase winding when the short circuit / over current occurs, the short circuit protection action lags behind, and the power tube in the controller Bear too long lag time, so that even if such an over-current protection circuit is adopted, many controllers are still damaged due to over-current

[0007] 2. For the method of detecting the power tube current of the phase winding, most of the existing technologies use the method of series sampling components to detect the sampling voltage drop, so that the sampling components such as the sampling resistor will inevitably generate a large current, sampling Resistors are prone to overheating, leading to open soldering, falling off or even burning, and increase energy consumption and installation area

[0008] 3. Many existing protection circuits, according to the sampling voltage or sampling current signal detected by the sampling element, after appropriate amplification, filtering, and shaping processing, send the overcurrent signal to the central processing chip, and the chip sends a signal to shut down the power tube. Gate drive pulses or the method of shutting off the bus power supply to obtain overcurrent protection. Due to the complexity of such circuits and the low reliability of software operation, controllers with such protection circuits still have considerable overcurrent damage. Rate

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