Electric Vehicle Relay Drive Fault Detection with Dual-Point Signals
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Solution Overview
Problem
Current fault detection solutions for relay drive circuits in electric vehicles are inadequate, posing safety risks due to aging mechanical relays and potential failures in wiring harnesses.
Innovation Solution
A detection circuit and method that utilizes a first and second detection module, along with a control module, to analyze electrical signals at specific points in the drive circuit to differentiate between normal and faulty states, including open-circuit and shorted-to-ground faults, using current-limiting and filtering modules to protect against excessive currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a relay is used to control high-voltage loops indirectly, then safety is improved, but the relay may face aging problems and fail after long-time work
Solution Approach 1:
The detection circuit performs preliminary detection of the relay drive circuit before failures occur. By continuously monitoring electrical characteristics and comparing them against predetermined thresholds, the system can identify aging relays and potential faults early, enabling preventive maintenance before the relay actually fails.
Solution Approach 2:
The detection circuit establishes a feedback mechanism that continuously monitors the relay drive circuit's electrical characteristics and provides feedback to the control unit. This feedback enables real-time assessment of relay health status, allowing the system to respond to degradation trends and predict remaining service life.
2Reliability
If fault detection solutions are added to relay drive circuits, then reliability is improved, but device complexity increases
Solution Approach 1:
The detection circuit is merged with the existing relay control system, sharing common components such as the control unit, power supply, and signal processing resources. The detection functions are integrated into the existing control architecture rather than adding completely separate monitoring systems, thereby reducing overall complexity.
Solution Approach 2:
The control unit performs multiple functions: it controls the relay switch unit, monitors electrical characteristics through detection modules, compares data against thresholds, and determines fault conditions. This multi-functionality eliminates the need for dedicated separate detection hardware, reducing device complexity while maintaining comprehensive fault detection capability.
Data Source
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AI summary
Embodiments of this application relate to the technical field of electronics, and disclose a detection circuit and a detection method of an electrical control device, and an electric vehicle. In some embodiments of this application, the detection circuit includes a drive circuit configured to detect an electrical control device. The drive circuit includes a drive power module and a low-side switch unit. The detection circuit includes: a first detection module, a second detection module, and a control module. The control module is configured to obtain an electrical signal at a third end of the first detection module, and/or an electrical signal at a second end of the second detection module; and determine, based on the electrical signal at the third end of the first detection module, and/or the electrical signal at the second end of the second detection module, whether the drive circuit of the electrical control device is faulty. In this implementation, fault diagnosis can be performed on the drive circuit of the electrical control device.