Adaptive Voltage-Dividing Circuit for Accurate Current Leakage Detection
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Solution Overview
Problem
Existing current leakage detection devices in vehicles with high-voltage circuits suffer from decreased detection accuracy due to aging deterioration or poor contact of detection resistors, leading to incorrect determination of current leakage.
Innovation Solution
A current leakage detection device with a first voltage dividing circuit, a resistor circuit in parallel, a switchable resistor circuit, and a control unit that adjusts the voltage-dividing ratio to maintain accurate detection by increasing the voltage-dividing value when it falls below a threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fixed voltage-dividing ratio is used in the detection circuit, then the circuit structure is simple, but detection accuracy decreases when insulation resistance changes due to aging or poor contact
Solution Approach 1:
The patent applies dynamics by making the voltage-dividing ratio adjustable rather than fixed. The control unit dynamically changes the voltage-dividing ratio based on detected insulation resistance values, allowing the system to adapt to aging and contact degradation while maintaining detection accuracy.
Solution Approach 2:
The patent changes the parameter of voltage-dividing ratio in response to changing insulation resistance conditions. By monitoring insulation resistance and adjusting the voltage-dividing ratio accordingly, the system compensates for degradation effects and maintains measurement precision over time.
2Measurement precision
If the voltage-dividing ratio is increased to improve detection accuracy, then detection resolution improves, but the detected voltage signal becomes larger potentially causing saturation
Solution Approach 1:
The patent uses feedback by continuously monitoring the detected voltage signal and adjusting the voltage-dividing ratio accordingly. The control unit receives feedback about the insulation resistance state and modifies the voltage-dividing ratio to keep the signal within the optimal detection range, preventing saturation while maintaining resolution.
Solution Approach 2:
The system dynamically adjusts the voltage-dividing ratio based on real-time detection conditions. When insulation resistance decreases, the control unit increases the voltage-dividing ratio to maintain signal strength without causing saturation, optimizing the detection range adaptively.
3Reliability
If detection resistors are used with high precision, then initial detection accuracy is high, but accuracy deteriorates over time due to aging and poor contact
Solution Approach 1:
The system implements feedback by monitoring insulation resistance values and using this information to adjust the voltage-dividing ratio. This compensates for resistor degradation and contact deterioration, maintaining detection accuracy over the lifespan of the system even as component conditions worsen.
Solution Approach 2:
The patent changes the voltage-dividing ratio parameter in response to changing component conditions. By detecting insulation resistance and adjusting the voltage-dividing ratio accordingly, the system compensates for aging effects and maintains stable detection performance over time.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device ensures high-accuracy current leakage detection by reducing detection errors even when insulation resistance decreases, suppressing circuit tolerance effects and maintaining resolution without altering the control unit's capabilities.
Implementation Method 1
a first voltage dividing circuit (30) connected to a power supply path side at one end and connected to a ground side at another end
Data Source
AI summary
A current leakage detection unit includes a first voltage dividing circuit, a resistor circuit connected in parallel with the first voltage dividing circuit, a switching unit that is configured to be switchable between energized and de-energized states of the resistor circuit, and a control unit that controls switching of the switching unit to acquire first voltage-dividing values from the first voltage dividing circuit and calculate an insulation resistance from the acquired voltage-dividing values to detect the current leakage. The first voltage dividing circuit includes a range change circuit that changes the voltage-dividing ratio of the first voltage dividing circuit. The control unit is configured to, when the first voltage-dividing values of the first voltage dividing circuit are less than the threshold value, change the voltage-dividing ratio of the first voltage dividing circuit to increase the first voltage-dividing value.