Over-current detection circuit and over-current protection circuit

Abstract

The invention discloses an over-current detection circuit and an over-current protection circuit. The over-current detection circuit comprises a current sensor, a current signal processing circuit and a current comparison circuit, wherein the current sensor is used for collecting current analog signals output by a motor power module, the current signal processing circuit is connected with the current sensor, converts the current analog signals collected by the current sensor into voltage signals capable of being measured by an operation amplifier, carries out filtering and isolation, and outputs the voltage value; the current comparison circuit is connected with the current signal processing circuit, compares the voltage value output by the current signal processing circuit with the preset reference voltage upper limit value and the reference voltage lower limit value, judges whether the voltage value exceeds the preset reference voltage upper and lower limit range or not, and outputs detection results. The analog signals are collected through the current sensor, the collected analog signals are sent to the current signal processing circuit, whether the over current occurs or not is detected through a comparator, the hardware is adopted for realizing the fast response of the current over flow fault, and the timely protection can be realized on the motor power module.

Description

technical field [0001] The present application relates to the field of circuit technology, in particular to an overcurrent detection circuit and an overcurrent protection circuit. Background technique [0002] As energy issues and environmental issues become increasingly prominent, the advantages of electric vehicles (including electric vehicles and electric bicycles) are increasingly accepted by people. Motors and motor controllers are the core components of electric vehicles, and their reliability is closely related to the personal and life safety of users. Therefore, it is particularly important to ensure the reliability of electric vehicle motors and motor controllers. [0003] In the prior art, electric vehicles generally use a permanent magnet synchronous motor as a drive motor, and the rotation of the permanent magnet synchronous motor is controlled by a motor controller, and a power module is used as a mainstream switching device in the motor controller. During the ...

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Problems solved by technology

[0004] But in above-mentioned prior art, the applicant finds, and the protection technology when the fault such as overcurrent, overvoltage occurs of existing motor controller, just does overcurrent, overvoltage to the system through the software program in the main control chip such as DSP chip. Overvoltage limitation, and this software current limiting technology implemented by the main control chip cannot timely capture the abnormal overcurrent signal in the system and make a quick and effective response, and it is difficult to quickly and effectively protect the motor

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