Pressure Control Method for Urban Rail Transit Brake Control Devices

Abstract

Objective As the core function of urban rail transit brake control devices, the structural principle design of pressure control is crucial for the brake control system. High-frequency switching solenoid valve pressure control method is the mainstream control approach, studying its structural characteristics is particularly important for enhancing the reliability of brake control devices. Method By analyzing different configurations of solenoid valves, the basic structures of five high-frequency switching solenoid valve pressure control methods are identified, including series exhaust, series pressure-holding, parallel exhaust, parallel pressure-holding, and parallel inflation. Their characteristics and applicable scenarios based on their failure modes are summarized. Result & Conclusion According to T/CAMET 04004.4—2018 ′Brake systems of urban rail vehicles Part 4: Technical specification of brake control units′, the exhaust-type pressure control structure is suitable for normal braking air circuits, while pressure-holding and inflation-type pressure control structures are suitable for emergency braking air circuits. The series pressure control structure maintains output pressure stability better than the parallel pressure control structure does, whereas the parallel pressure control structure has a faster inflation rate compared to the series pressure control structure. When designing the pressure control structure of brake control devices, it is essential to comprehensively consider factors such as the target pressure control accuracy, inflation and exhaust rate requirements, and solenoid valve control strategies, and to configure the chamber volume and pipeline diameter appropriately.

Keywords

• urban rail transit
• brake control device
• pressure control method