Vehicle Ground Fault Control for Solenoid Power Limiting
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Solution Overview
Problem
Existing vehicle control systems face failures due to disconnection of the ground line between the controller system and the power system, leading to continuous high current flow and battery exhaustion, especially when the electric wire connected to the first ground portion breaks.
Innovation Solution
A control device with a divided ground system, where the control circuit measures voltages of the power supply portions relative to both ground portions and sets the power supply to a predetermined value or less when a predetermined relationship between these voltages is detected, preventing high current flow to the solenoid load and thus preventing system failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single ground line is used to connect the battery to both the control circuit and power circuit, then the device complexity is reduced, but the reliability deteriorates due to potential ground disconnection causing continuous high current flow
Solution Approach 1:
The ground connection is segmented into two separate ground lines: a first ground line connecting the battery's negative electrode to the control circuit's ground, and a second ground line connecting the battery's negative electrode to the power circuit's ground. This segmentation allows independent monitoring of each ground connection, enabling the control circuit to detect disconnection in either line and respond by limiting power supply to prevent continuous high current flow, thereby improving reliability without excessive complexity.
2Reliability
If the control circuit continuously monitors voltage to detect ground disconnection, then the reliability is improved, but the use of energy increases due to continuous monitoring and potential continuous high current flow
Solution Approach 1:
The control circuit implements a feedback mechanism by continuously monitoring the voltage between the first ground portion and the second ground portion. When a disconnection is detected (voltage exceeds a predetermined threshold), the control circuit provides feedback to limit the power supply to the power circuit, reducing current flow and energy consumption. This feedback-based approach ensures reliable detection of ground disconnection while managing energy consumption by actively responding to detected faults.
3Productivity
If power supply is not limited after ground disconnection detection, then the productivity is maintained, but the object-affected harmful factors increase due to continuous high current flow causing solenoid load deterioration
Solution Approach 1:
The control circuit implements preliminary anti-action by detecting ground disconnection before it causes significant harm to the solenoid load. Upon detecting a voltage anomaly indicating ground disconnection, the control circuit proactively limits the power supply to the power circuit, preventing continuous high current flow that would otherwise deteriorate the solenoid load. This preliminary protective action stops the harmful process before substantial damage occurs, balancing productivity maintenance with component protection.
Data Source
AI summary
A vehicle includes first and second power supply cords. Positive and negative electrodes of a battery are connected to a first power supply portion and a first ground portion of a first circuit, respectively, by the first power supply cord, and connected to a second power supply portion and a second ground portion of the second circuit, respectively, by the second power supply cord. The first circuit includes a control circuit configured to measure voltages of the second power supply portion as a first voltage and as a second voltage with reference to a potential of the first ground portion and a potential of the second ground portion, respectively. In a case in which the first and second voltages have a predetermined relationship, power supplied from the second power supply cord to the second circuit is set to be a predetermined value or less.