Relay Fixation Detection via Insulation Resistor Voltage Divider
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Solution Overview
Problem
Existing systems for determining relay fixation in battery packs require frequent switching of relays ON and OFF, leading to wear on contact points and making it difficult to accurately assess relay status without causing errors due to leaks or temperature changes.
Innovation Solution
A system using insulation resistors and a detection circuit to differentiate between relay fixation states by analyzing voltage values obtained from alternating-current signals, eliminating the need to switch relays ON and OFF for determination, and employing different frequencies to enhance accuracy and reduce processing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If relays are switched ON and OFF frequently to determine fixation status, then relay fixation detection accuracy is improved, but contact point wear increases
Solution Approach 1:
The patent replaces the mechanical relay switching operation with an electrical measurement system. Instead of physically switching relays ON and OFF to detect fixation, the system uses a detection circuit to measure voltage values across the relay while it remains in a single state (OFF). The detection circuit applies an AC signal and measures the voltage divider effect caused by insulation resistors, thereby substituting mechanical contact wear with non-contact electrical measurement.
Solution Approach 2:
The patent introduces insulation resistors as intermediary elements to enable fixation detection without direct relay switching. The first insulation resistor (connected to the electricity storage device) and second insulation resistor (connected to the electrical apparatus) create a voltage divider circuit that reflects the relay's fixation state. By measuring the voltage across these resistors, the system can determine relay status through an intermediary electrical path rather than direct mechanical contact.
2Measurement precision
If relay switching is performed to detect fixation, then fixation status can be determined, but processing time increases due to multiple switching operations
Solution Approach 1:
The patent performs preliminary setup by configuring the insulation resistors and detection circuit before relay fixation detection is needed. The first insulation resistor is pre-connected between the electricity storage device and ground, and the second insulation resistor is pre-connected between the electrical apparatus and ground. This preliminary configuration allows the system to perform detection by simply measuring voltage without needing to perform time-consuming switching operations at the moment of detection.
Solution Approach 2:
The detection circuit continuously monitors the voltage value across the insulation resistors, maintaining readiness to detect relay fixation at any time. The AC signal is continuously applied, and the voltage measurement is ongoing, allowing the system to detect relay status changes immediately without interruption or repeated switching cycles, thereby eliminating detection delays.
3Duration of action of moving object
If voltage detection is performed with relay OFF, then relay wear is reduced, but detection accuracy may be affected by insulation resistance variations
Solution Approach 1:
The patent utilizes parameter changes in the insulation resistors to encode relay fixation information. The first insulation resistor has a higher resistance value than the second insulation resistor, creating a specific voltage divider ratio. When the relay is fixed in the ON position, this resistance parameter difference produces a detectable voltage pattern that distinguishes fixation from normal OFF state, thereby maintaining detection accuracy without requiring relay switching.
Solution Approach 2:
The system creates an electrical copy of the relay's connection state through the insulation resistor voltage divider circuit. Instead of directly measuring relay contact resistance (which would require switching), the system measures the voltage across the insulation resistors, which replicates the effect of relay connection status. This electrical copy allows accurate detection of relay fixation while the relay remains in the OFF position, preserving contact point lifespan.
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 system accurately determines relay fixation without wear, minimizes errors from leaks and temperature changes, and reduces the need for relay switching, thereby extending relay lifespan and improving diagnostic precision.
Implementation Method 1
The detection circuit outputs an alternating-current (AC) signal of a reference voltage value to the electricity storage device and detects a voltage value obtained by dividing the reference voltage value by a reference resistance value
Implementation Method 2
The system for determining fixation of a relay has the first insulation resistor between the electricity storage device and a ground and the second insulation resistor between the electrical apparatus and the ground. A first resistance value of the first insulation resistor is larger than a second resistance value of the second insulation resistor
Data Source
AI summary
A system for determining fixation of a relay has an electricity storage device, an electrical apparatus, a relay, a first insulation resistor, a second insulation resistor, a detection circuit, and a controller. When the relay is controlled to OFF, the controller determines, based on the voltage value detected by the detection circuit (the detected voltage value), whether or not the relay is fixed. When the detected voltage value is a voltage value that is obtained by dividing the reference voltage value by a combined resistance value and the reference resistance value, the controller determines that the relay is fixed. When the detected voltage value is a voltage value that is obtained by dividing the reference voltage value by the first resistance value and the reference resistance value, the controller determines that the relay is not fixed.