Electric Charging Control Device Welding Abnormality Detection
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Solution Overview
Problem
Existing electric charging control devices for electric vehicles face challenges in accurately detecting welding abnormalities in electric charging contactors and main electric contactors, leading to potential energized and exposed portions during plug mating and unmating, and require expensive and complex voltage sensors to handle wide voltage ranges.
Innovation Solution
An electric charging control device with a voltage monitoring circuitry that uses a pair of voltage monitoring circuits connected between upstream and downstream power-supply points to produce determination logic signals, preventing energized exposure by prohibiting close-circuit instructions when abnormalities are detected, and employing a voltage-level detection circuit to determine main power-source voltage applied from the main battery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage sensors are used to detect welding abnormalities in electric charging contactors and main electric contactors, then detection accuracy is improved, but device cost and complexity increase due to expensive sensors required for wide voltage ranges
Solution Approach 1:
The voltage monitoring function is segmented into multiple discrete voltage monitoring circuits, each responsible for monitoring specific voltage ranges or specific contactor circuits. This segmentation allows each circuit to be optimized for a narrower voltage range, reducing the complexity and cost of individual circuits while maintaining overall detection accuracy across the full voltage range.
Solution Approach 2:
The patent introduces intermediate voltage monitoring circuits that act as mediators between the high-voltage charging circuits and the control system. These intermediate circuits condition and scale voltage signals before they reach the control processor, enabling accurate welding abnormality detection without requiring expensive wide-range voltage sensors directly in the control system.
2Reliability
If voltage sensors are used to detect welding abnormalities, then detection capability is improved, but device cost increases due to expensive sensors for wide voltage ranges
Solution Approach 1:
The patent employs multiple relatively simple and inexpensive voltage monitoring circuits rather than a single expensive high-performance voltage sensor. By using multiple lower-cost circuits that can be easily replaced if needed, the system achieves high detection reliability without the high cost of premium sensors.
Solution Approach 2:
The patent combines multiple voltage monitoring circuits into a unified monitoring system that collectively provides comprehensive coverage of all voltage ranges and contactor circuits. This merging approach distributes the reliability requirement across multiple components, achieving system-level high reliability through redundancy and coverage without requiring any single component to be expensive.
3Measurement precision
If multiple voltage monitoring circuits are used to monitor different voltage ranges, then welding abnormality detection accuracy is improved, but circuit complexity increases
Solution Approach 1:
Each voltage monitoring circuit is designed with local quality optimization, meaning each circuit is specifically tailored to monitor a particular voltage range or particular contactor circuit with high precision. This localized optimization allows each circuit to use component values and design parameters best suited for its specific function, improving overall measurement precision while keeping individual circuits relatively simple.
Data Source
AI summary
An electric charging control device is obtained which detects welding abnormality of an electric contactor(s) along charging passages from an electric charging plug reaching a main battery; electric charging contactors and main electric contactors are connected in series; a first voltage monitoring circuit connected between power-supply points P1 and N1, a second voltage monitoring circuit connected therebetween, and a voltage-level detection circuit connected between the midpoints P2 and N2 are provided for producing a first voltage detection signal DET1, a second voltage detection signal DET2, and a main voltage detection signal DET0, each of which is a respective determination logic signal responding to the presence or absence of a monitored voltage; and a test voltage is received from either one of the main battery and a ground-based electric charging power-source apparatus, so that the presence or absence of welding abnormality in any one of the contactors is determined.