Vehicle Control Device Sensor Inspection via Voltage Difference
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Solution Overview
Problem
Existing car control devices for railroad cars require a dedicated circuit or test mode to inspect sensor malfunctions, leading to increased device size and the need for specific test environments, which is inconvenient and inefficient.
Innovation Solution
A car control device with a converter, inverter, contactors, and voltage detectors that calculates and compares voltage differences to determine sensor malfunctions without a dedicated circuit or test mode, allowing for continuous inspection during normal operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dedicated circuit or test mode is provided to inspect sensor malfunctions, then the reliability of sensor detection is improved, but the device size increases and the operation becomes more complex
Solution Approach 1:
The control unit performs multiple functions: it controls the contactors for normal power conversion operations and simultaneously inspects the voltage detectors for malfunction detection. This multi-functionality eliminates the need for a dedicated inspection circuit, reducing device size while maintaining reliable sensor monitoring capability
Solution Approach 2:
The system inspects its own sensors using existing operational components. The control unit utilizes the normal operating voltage differences detected by the voltage detectors to determine whether they are malfunctioning, without requiring external test equipment or dedicated inspection circuits
2Measurement precision
If a test mode is provided to inspect sensor malfunctions, then the measurement precision of sensor status is improved, but the ease of operation deteriorates due to requiring specific test environments
Solution Approach 1:
The inspection of voltage detectors is performed continuously during normal operation rather than requiring a separate test mode. The control unit calculates voltage differences and determines malfunction status throughout the entire operational period, ensuring both high measurement precision and operational convenience
Solution Approach 2:
The control unit performs malfunction inspection of voltage detectors before they are needed for critical power conversion operations. By inspecting the sensors in advance during normal operation, the system ensures measurement precision while maintaining ease of operation without requiring separate test environments
Data Source
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AI summary
[Problem] To provide a car control device capable of inspecting a sensor without using a dedicated circuit or a test mode. [Solving Means] A car control device according to an embodiment includes a converter and an inverter configured to covert power received by a pantograph to power for driving a motor, a first contactor disposed between the transformer and the converter, a second contactor and a resistor connected in series with each other and in parallel with the first contactor, a first voltage detector and a second voltage detector disposed between the converter and the inverter, and a control unit. After the second contactor is closed and before the first contactor is closed, the control unit calculates a voltage difference between a first voltage value detected by the first voltage detector and a second voltage value detected by the second voltage detector, compares the calculated voltage difference with a predefined threshold value, and determines that at least one of the first voltage detector and the second voltage detector malfunctions when the voltage difference is greater than the threshold value.