Railcar Torque Control for Noise Reduction
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Solution Overview
Problem
High-grade railcars configured as power cars face challenges in maintaining a quiet environment due to increased noise levels from traction motors and other noise sources, as existing technologies do not provide adequate measures to reduce internal noises in specific cars within a train set.
Innovation Solution
A railcar control device that adjusts torque commands for traction motors and output commands for internal combustion engines, ensuring that a specific traction motor or engine produces lower torque or output than others when the required value is below the maximum, thereby reducing noise levels in specific cars.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a high-grade car is configured as a power car to satisfy the demand for increased speed, then the speed performance is improved, but the internal noise level increases and quietness deteriorates
Solution Approach 1:
The patent applies local quality by making different traction motors have different torque characteristics. Specifically, the traction motor located in the high-grade car is designed with different torque properties compared to other traction motors, allowing it to produce lower noise while still contributing to the overall tractive effort. This resolves the contradiction by enabling the high-grade car to remain a power car (maintaining speed performance) while its specific traction motor operates with optimized noise characteristics.
2Power
If the torque of all traction motors is increased to provide more power, then the tractive performance is improved, but the noise from specific traction motors increases
Solution Approach 1:
The patent implements local quality by assigning different torque characteristics to different traction motors based on their location. The traction motor in the high-grade car is configured to produce lower torque under certain operating conditions, thereby reducing noise generation in that specific location while other traction motors can operate at higher torque levels to maintain overall tractive power.
Solution Approach 2:
The patent applies dynamics by enabling the traction motor in the high-grade car to dynamically adjust its torque output based on operating conditions. The control system varies the torque characteristics of this specific traction motor according to the train's speed, load, and positioning, allowing it to reduce noise during operations where high torque is not critically needed while maintaining sufficient power when required.
3Adaptability or versatility
If a specific apparatus (e.g., power collector) is mounted on a specific car to enable operation, then the functionality is improved, but the internal noise level of that specific car increases
Solution Approach 1:
The patent addresses this contradiction by applying local quality to the traction motor associated with the noisy car. When a power collector or other noisy apparatus is mounted on a specific car, the traction motor in that car is configured with different torque characteristics to compensate for the additional noise from the mounted apparatus. This allows the car to maintain its necessary functionality while the traction motor's optimized characteristics help mitigate the overall noise impact in the passenger compartment.
Data Source
AI summary
A railcar control device controls a plurality of traction motors included in a train set. The railcar control device includes: a control command input portion to which a control command is input; and a torque command determining portion configured to determine torque commands with respect to a plurality of traction motors such that when a required torque based on the control command input to the control command input portion is less than a maximum value, a torque of a specific traction motor among the plurality of traction motors is made lower than a torque of a different traction motor other than the specific traction motor.