Train Traction Unit Rotation for Variable Motor-Trailer Ratio
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Solution Overview
Problem
Rail transit trains with fixed motor-to-trailer ratios face inefficiencies in energy consumption and system losses due to varying passenger loads and operational requirements, leading to wasted energy during low passenger flow periods and inadequate performance for different line conditions.
Innovation Solution
A control method for variable motor-to-trailer ratio trains that adjusts traction force distribution based on operation information, including line, passenger load, and weather conditions, dynamically switching traction units on and off to match actual demand, and unevenly distributing traction and braking forces among units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed motor-to-trailer ratio is used, then the train can meet the highest traction demand, but energy is wasted during low passenger flow periods
Solution Approach 1:
The patent implements dynamic adjustment of the motor-to-trailer ratio based on real-time operational conditions including passenger load, line characteristics, and weather state. The control system calculates required traction force and dynamically reconfigures which carriages function as motor cars versus trailer cars, allowing the train to adapt its power distribution from a fixed static configuration to a flexible dynamic state that matches actual demand.
Solution Approach 2:
The system changes the operational parameter of motor-to-trailer ratio based on varying conditions. By monitoring passenger load, line information, and weather state, the control method adjusts the number of active motor cars and trailer cars, transforming the fixed parameter into a variable one that optimizes energy consumption while maintaining sufficient traction capability.
2Power
If all traction units operate continuously, then sufficient traction force is available, but maintenance intervals are shortened
Solution Approach 1:
The train's traction system is segmented into multiple independent traction units (motor cars) that can operate independently. Instead of running all traction units continuously, the system divides them into active and standby groups, allowing some units to rest while others provide traction force. This segmentation enables load distribution across multiple units over time, extending their individual service life and maintenance intervals.
Solution Approach 2:
The control method implements periodic rotation of traction unit usage patterns. By cycling through different combinations of active motor cars based on accumulated working hours, the system ensures that no single traction unit operates continuously. This periodic alternation between active and standby states allows traction units to rest and cool down, thereby extending their operational duration before maintenance is required.
3Device complexity
If a fixed motor-to-trailer ratio is used, then system configuration is simple, but adaptability to different line conditions is poor
Solution Approach 1:
The patent makes the train system universal by enabling each carriage to potentially function as either a motor car or a trailer car depending on operational requirements. The control system evaluates line characteristics, passenger load, and weather conditions to determine the optimal configuration, allowing the same physical train to adapt its functional configuration for different scenarios such as subway lines requiring high acceleration versus intercity lines requiring higher speed.
Data Source
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AI summary
Provided are a train variable motor-to-trailer ratio control method, a controller and a train, relating to the technical field of rail transit. The method comprises: on the basis of acquired train operation line information, location information, passenger capacity, rail surface state and weather state, calculating a first traction force required for the train operation; non-uniformly distributing the first traction force to traction units; monitoring the accumulated working time of each traction unit that is providing a traction force; and once the accumulated working time is greater than a set first duration threshold, disabling the corresponding traction unit, and switching to another traction unit that is not providing a traction force. The traction force is distributed nonuniformly, and the traction units of different carriages are rotated according to the accumulated working time, so as to control a variable motor-to-trailer ratio. An adaptive traction force can be provided on the basis of actual traction force requirements, thereby reducing the loss of a traction system itself and auxiliary energy consumption, achieving energy saving of the system.