Pantograph Relay Valve Pressure Control for Precise Contact Force
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Solution Overview
Problem
Current systems for controlling contact force between a pantograph and a contact line in electric traction vehicles lack precision and efficiency, particularly at high speeds and when stationary, leading to issues like contact interruptions, mechanical misalignment, and energy wastage due to high air consumption.
Innovation Solution
A pneumatically or hydraulically actuated device using a relay valve with two pilot control pressures to regulate working pressure, allowing for precise control of contact force by adjusting pilot pressures and limiting maximum pressure to prevent damage, while minimizing media consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electro-pneumatic pressure control is used to increase contact force precision, then control precision is improved, but air consumption increases significantly
Solution Approach 1:
The patent replaces the electro-pneumatic control system with a purely pneumatic control system using a relay valve. The relay valve uses pilot pressures to control the main working pressure without requiring continuous electrical actuation, thereby maintaining contact force precision while significantly reducing air consumption by eliminating the need for continuous compressor operation.
Solution Approach 2:
The patent changes the control parameter from electrical signals in electro-pneumatic systems to pneumatic pilot pressures. By using two pilot pressures (first and second pilot pressures) to control the relay valve, the system achieves precise contact force regulation through pressure parameter modulation rather than continuous electrical power input, reducing energy loss.
2Force
If wind deflectors are used to increase aerodynamic force at high speeds, then contact force is improved, but adaptability to different operating situations deteriorates
Solution Approach 1:
The patent implements a dynamic control system using a relay valve that can rapidly adjust the contact force by switching between different pilot pressure levels. This dynamic pneumatic control allows the system to adapt to various operating conditions (high speed, low speed, stationary, tunnel, open track) by modulating the working pressure in real-time, unlike fixed wind deflectors which provide static aerodynamic force.
Solution Approach 2:
The relay valve control system serves multiple functions: it can increase contact force at high speeds, maintain force during stationary periods, and adapt to different track conditions. The single pneumatic control system replaces multiple specialized components (wind deflectors for speed, separate mechanisms for stationary force) with a universal pressure control mechanism that handles all operating scenarios.
3Device complexity
If single-stage or two-stage pressure control is used, then device complexity is reduced, but control precision deteriorates
Solution Approach 1:
The patent introduces a relay valve as an intermediary component between the simple two-stage pressure source and the pantograph. The relay valve uses small-diameter pilot pressure inputs to control the large-diameter working pressure output, acting as a mediator that amplifies the control effect. This allows simple two-stage pressure control to achieve precise contact force regulation through the relay valve's pressure amplification and modulation capabilities.
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
This solution provides precise control of contact force across varying operating conditions, reducing energy wastage and preventing damage to pantograph and contact line components, enhancing energy efficiency and service life.
Implementation Method 1
The required contact force is achieved by increasing the working pressure, which is made possible by controlling or regulating a power pressure using two pilot pressures from a pilot circuit
Implementation Method 2
During the raising or lowering of the pantograph, the media pressure is in equilibrium with the gravity (weight) of the pantograph
Implementation Method 3
A pneumatically or hydraulically actuated device using a relay valve with two pilot control pressures to regulate working pressure
Data Source
Figure 1~2
AI summary
The invention relates to a device (22) for controlling a required pressing force from a current collector (12) of a vehicle (10) on an overhead line (20), a method for using such a device (22) and a power car (10) having at least one such device (22), wherein the device (22) has a pilot control circuit (32), a working pressure control circuit (60) and an adjustment device (50) including a relay valve (40). The pilot control circuit (32) adjusts a pilot control pressure and the relay valve (40) uses a pilot control pressure in order to control a power pressure in order to provide a required working pressure for the pressing force of the current collector.