The dual-powered urban trains run on the Chongqing Rail Transit Jiangtiao Line. [Photo provided to gojilin.gov.cn]

Dual-powered urban trains, independently developed by CRRC Changchun Railway Vehicles Co, officially started operating on Aug 6 on the Chongqing Rail Transit Jiangtiao Line – in Chongqing municipality in Southwest China – marking the country's first batch of trains adopting dual-powered automatic switching technology.

The current power supply system used by China's rail transit is usually divided into AC 25 kV and DC 1.5 kV systems.

Due to different power supply systems and vehicle limits, subways, monorail trains and urban (suburban) railway trains belong to two track networks. They have different technical characteristics and usually can't run across lines.

The interior of the new and advanced train. [Photo provided to gojilin.gov.cn]

But the dual-powered urban train developed by CRRC Changchun can run on both AC 25kV and DC 1.5kV power supply lines. It can complete dozens of switching actions within one minute, realizing the interconnection of the two standards.

By switching between the systems, the continuous operation of suburban railways and urban rail transit can be realized, filling the gap in domestic rail transit technology.

The train uses noise analysis and control technology to integrate acoustic designs into the whole vehicle design.

The comprehensive optimization and improvement of wheel-rail noise, electrical equipment noise and aerodynamic noise aims to provide a more comfortable ride for passengers, but also reduces the impact on the surrounding environment.

The train is equipped with intelligent monitoring equipment such as a bogie axle temperature monitoring system, a battery health management system and pantograph and catenary monitoring system, to realize real-time monitoring of the operating status of key equipment.