Battery powered trains
The BEMU is an EMU (Electrical Multiple Unit) equipped with an OESS (Onboard Energy Storage System), which main function is storing and managing the electric energy. This system is based on advanced batteries integrated into the train itself, capable of capturing and storing energy from catenary and regenerative braking. The stored energy is used mainly in areas without electrification, where it cannot access the power grid but also during train acceleration under catenary.
Under catenary, the OESS system simultaneously pulls and loads the batteries. In addition, the system also powers the train’s auxiliary system, such as lighting, air conditioning and communication systems, contributing to a more efficient and autonomous operation.
Driver assistance and energy management system (DASEM)
DASEM is an advanced technology designed to optimise energy efficiency, reduce operating costs and carbon emissions. The system analyses a large amount of real-time data such as train status, train current speed, route profile (curved, gradients), stations and timetables and provides precise recommendation to the driver on when to accelerate, brake, maintain a constant speed or shut down some of the engines.
Train Data is modified dynamically as the values will depend on the train formation and power mode, failure or external requirements. Timetable and route characteristics can also be modified during the journey to take into account the most update situation.
DASEM is also responsible for managing the energy of the vehicle and adjusting the consumption so that the efficiency of the same is optimal and that at no time the train will run out of onboard energy. DASEM knows the real value of the total energy stored in the OESS system every moment and calculates the energy necessary to reach the next charging point. DASEM will ensure that the OESS System does not run out of power. On this regard, if DASEM detects that the current stored energy at a certain moment is lower than the required energy (to reach the next energy charging point) then it will perform a series of actions to prevent this from happening; new smooth profile, new comfort functions…
DASEM is also responsible for charging the OESS system. In catenary zones, the system takes advantage of the journey duration under catenary to optimize charging power, reduce peaks, and minimize losses, thereby increasing the battery lifespan.
Information display to driver
Except when the advisory information is disabled, the DASEM displays the following information:
- Current Advice: Current Train Speed, Advice Speed and an indication to reach or maintain a SPEED, COAST or APPROACH STATION.
- Approach Advice
- Status of the system
- Additional Journey Information
Operating mode
DASEM system can operate both in Manual and Automatic mode.
Operating in MANUAL mode, the speed profile is the input for the calculation of the advisory information: mainly recommended speed and driving commands (traction, brake or coast).
While, on the AUTOMATIC mode, the calculated speed profile is the main input for the calculation of the brake and traction commands to be sent to the on-board subsystems and apply traction and brake without drivers command.