Ground wire short circuit protection circuit, automobile motor controller and electric automobile

Abstract

The invention provides a ground wire short-circuit protection circuit, a ground wire is connected between a sensor and a controller, the protection circuit comprises an execution module and a control module, the execution module is connected in series in the ground wire, and the control module is connected with the ground wire and used for detecting whether the voltage value of the ground wire is abnormal or not. The control module is connected with the control end of the execution module and used for controlling on-off of the execution module, if the voltage value of the ground wire is abnormal, the control module disconnects the execution module to disconnect the ground wire, and if the voltage value of the ground wire is normal, the control module connects the execution module to connect the ground wire. According to the invention, the problem that wrong trigger protection is easy to cause due to large resistance change of the thermistor along with temperature change is solved. The invention further provides an automobile motor controller and an electric automobile.

Description

technical field [0001] The invention relates to the technical field of circuits, in particular to a ground wire short-circuit protection circuit, an automobile motor controller and an electric vehicle. Background technique [0002] In the traditional signal acquisition system, the controller generally provides power to the external sensors, and collects feedback signals from the sensors to achieve the purpose of measurement. To collect feedback signals, a common reference ground wire is required between the sensor and the controller. Generally, the common reference ground wire is the power ground wire. The power supply ground wire of the sensor and the reference ground wire of the controller are equipotential bonding. In the event of a short circuit in the sensor circuit, etc., excessive current may flow through the sensor supply ground. The fault state of the circuit can be detected by detecting the voltage value of the power supply ground terminal, and then measures are ...

AI Technical Summary

Problems solved by technology

[0004] In the process of realizing the present invention, the inventors have found that there are at least the following problems in the prior art: the PTC (Positive Temperature Coefficient, positive temperature coefficient) thermistor itself is affected by temperature, and the internal resistance changes greatly, which has unpredictable influence on the sampling system. performance, resulting in poor system stability, and prone to false triggering in high temperature environments

The scheme of sampling resistor plus protection switch, during the application of short circuit, the protection switch will continue to switch due to the change of the current on the sampling resistor, which will cause serious heating of the switching device, and the actual circuit is not completely closed

At the same time, connecting the sampling resistor in series with the power ground wire will inevitably cause the reference ground voltage to shift, resulting in inaccurate sampling

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