Charging Device Relay Welded Contact Detection
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Solution Overview
Problem
Existing charging devices for electric vehicles face issues with smooth operation due to welded relay contacts, which can lead to persistent electrical leakage and hinder charging processes.
Innovation Solution
A charging device with a relay unit, leakage detecting circuit, and test circuit that securely interrupts the electric power supply path by examining the relay's operation and preventing charging if a welded contact is detected, ensuring safe and uninterrupted power transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the relay is turned on to check the operation of the leakage detecting circuit, then the leakage detecting function can be verified, but the control circuit cannot interrupt the electric power supply path after checking if the relay has a welded contact
Solution Approach 1:
The patent applies preliminary action by performing a relay operation check before enabling the leakage detecting function. The control circuit attempts to turn off the relay after it has been turned on for testing, and only enables the leakage detecting function if the relay successfully interrupts the power supply path. This preliminary verification prevents the system from operating with a potentially welded relay contact.
Solution Approach 2:
The patent implements preliminary anti-action by proactively detecting and preventing the harmful condition of a welded relay contact before it can cause persistent electrical leakage. The control circuit checks whether the relay can properly interrupt the power supply path, and if not, prevents the leakage detecting function from being enabled, thereby counteracting the potential harm before it occurs.
2Reliability
If the relay contact is welded, then the electric power supply path remains continuously closed, but electrical leakage cannot be detected and interrupted
Solution Approach 1:
The patent performs a preliminary check of the relay's interruption capability before enabling the leakage detecting function. The control circuit attempts to turn off the relay and verifies whether the power supply path is properly interrupted. Only if this preliminary test succeeds does the system enable the leakage detecting function, ensuring the relay is functional before relying on it for safety.
Solution Approach 2:
The patent implements feedback by monitoring whether the relay successfully interrupts the power supply path during the operation check. The control circuit receives feedback from the voltage detection circuit about whether voltage is still present at the relay output, and based on this feedback, decides whether to enable the leakage detecting function or prohibit charging operation.
3Productivity
If the leakage detecting circuit is enabled without verifying relay operation, then charging can start quickly, but the system cannot respond to electrical leakage if the relay is welded
Solution Approach 1:
The patent performs a quick preliminary check of the relay's interruption capability before enabling the leakage detecting function and starting charging. This preliminary action verifies the relay is functional without significantly delaying the charging process, as the check is performed automatically during the initialization sequence before the user would notice any delay.
Solution Approach 2:
The system performs a preliminary verification of the relay's interruption function before enabling the leakage detecting circuit. The control circuit attempts to turn off the relay and checks if the power supply path is properly interrupted. Only after this preliminary verification succeeds does the system enable the leakage detecting function, ensuring both reliability and reasonable charging speed.
Data Source
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AI summary
A test circuit (260) first detects whether or not a relay unit (210) is normal, and then examines an operation of leakage detecting circuit (240). This allows relay unit (210) to interrupt an electric power supply path including power lines (PL11, PL12, PL21, PL22) more securely if electrical leakage occurs in the electric power supply path. If welding in the contact of the relay unit (210) is detected before starting charging of a power storage device (B) included in an electrical device (100), a control device (60) does not allow the charging of the power storage device (B), which can prevent a problem from occurring in the electrical device (100).