Integrated control and monitoring for battery-powered train

Valence Technologies, with which Sensor-Technik UK has worked for over seven years, was contracted by train manufacturer Bombardier Transportation to provide the battery power for the train. The overall aim of the development was to bridge the gaps between electrified parts of the network and to run on branch lines where it would be too expensive to install overhead electrification.

Sensor-Technik UK was commissioned by Valence Technologies to design and develop an intercommunication and master battery system (MBS) that would sit between the battery packs and the train control system (TCMS). The intrinsic chemical stability of the cells and secondary safety controls, firewire detection, isolation and containment measures on board provided the elements for safety-case approval in passenger service. For this application the DC power supply was split across two separate packs of batteries, each pack containing six Valence U-BMS (battery management systems). The system design required that each pack be controlled by a dedicated master controller, which are then linked by a dedicated CAN-bus onto which the train was also connected in order to provide an overall system level of data.

Master CAN controller

For the master controller Sensor-Technik UK selected the STW ESX-3XM control unit with EB06 expansion board. The ESX-3XM is a compact electronic controller providing the end-user with multiple control, monitoring and interface options. It has been designed to be very robust, operating well in diverse and demanding environments. As standard the ESX-3XM has a powerful 32-bit Tricore processor, four separate CAN channels and room for up to three expansion boards - providing significant I/O capabilities and system functionality.

Each ESX-3XM is responsible for monitoring the state of each U-BMS in the pack, managing faults and analysing operational data to produce a 'pack-level' of data that is then transmitted on to the train controller to take control action. The bespoke control algorithms developed for this application are based on the years of experience Sensor-Technik UK has built-up in control and measurement application development and design.

Remote monitoring system

As part of the delivery, Sensor-Technik UK was also tasked with providing a remote monitoring system for the trial, allowing key stakeholders access to relevant operational data as well as detailed remote diagnostics for Valence engineers. For this, Sensor-Technik UK provided a telematics unit from STW - the ESX-TC3G. The ESX-TC3G is a Linux-based communication and teleservice module of exceptional capability. With multiple interfaces it can form the basis for an exceptionally broad range of applications. Alongside standard interfaces such as RS232, USB and Ethernet, the module offers wireless communications via Bluetooth, 2G/3G and WLAN. The built-in GPS/GLONASS module continuously provides the current position. The hardware is available with internal and external antennae.

As part of the delivery Sensor-Technik UK was required to develop and support the application software for both the ESX-3XM and ESX-TC3G. Using the Sensor-Technik UK Coding Guidelines and adhering to IEC 61508 (Functional Safety of Electrical/Electronic/Programmable Electronic Safety-related Systems), Sensor-Technik UK and its partners provided a comprehensive set of control algorithms that allowed rapid deployment of the system to facilitate installation and testing. The early design and validation work of the communications interfaces and mitigation activities ensured that minimal errors were seen during commissioning.

Telematics

For the telematics system, Sensor-Technik UK turned to its partner, Hamatics Ltd, to provide the off-board database and web system to which the ESX-TC3G transmits all operational data via its built-in 3G data connection. Hamatics Ltd offer flexible database and web products to the mobile and off-highway machinery markets. In this instance, Hamatics developed a bespoke database and website capable of handling many thousands of data inserts per day, with powerful analytic tools and metric-based graphical interfaces. This website enabled the key stakeholders, each with different levels of access depending on their interest in the train, to analyse the operation, efficacy and impact of the train.

The new battery-powered train contributes to Network Rail's commitment to reduce its environmental impact, improve sustainability and reduce the cost of running the railway by 20 per cent over the next five years. It could ultimately lead to a fleet of battery-powered trains running on Britain's rail network that are quieter and more efficient than diesel-powered trains, making them better for passengers and the environment.

To learn more about Sensor Technik's control and monitoring systems please visit www.sensor-technik.co.uk.