The Hybrid Commercial Vehicle (HCV) project aims to develop urban buses and delivery vehicles with advanced second generation of energy efficient hybrid electric powertrains.

Sub-Project 3000 - Energy storage system

One of the key technologies for cleaner and more efficient commercial vehicles is the electric energy storage system, which is an important technology able to carry out several functions in hybrid drive-trains. The performance characteristics, the reliability (abuse tolerance) and costs are key aspects that must be carefully evaluated and optimised to allow for a larger application of hybrid systems. The current state of the art on these topics is quite clear: the targeted lifetime and safety issues of storage systems are not yet fully experimentally verified in hybrid vehicle applications because of the availability period of most storage technologies is much shorter than the prospected lifetime. The SP3000 will concentrate on two energy storage technologies, which may play a fundamental role in the success of the hybrid vehicles: lithium-ion batteries (Li) and electrochemical supercapacitors (SC).

The main objectives of SP3000 are:

  • to improve the reliability/safety and reduce the costs of the Electric Energy Storage;
  • to carry out basic characterization for evaluation & bench test of technologies/suppliers (including, for the power buffer type, supercapacitors) allowable for short-medium term industrial applicability;
  • to carry out ageing, life testing and modelling for application evaluation and for control needs and optimisation (with estimation of State of Health and State of Life).

The activities will be carried out at cell and module level on both technologies.

The SP3000 activities will also take advantages from a collaboration and integration with a Swedish national research project, which is carried out as cooperation between the Uppsala University (research on electrode materials), Royal Institute of Technology (applied electrochemistry) and Volvo. The cycle life and degradation mechanisms of Li and SC cells are not fully understood and are strongly depending on the technology and the operating conditions. The testing plan and related characterization procedures will be aimed to investigate the potential cycle life and accelerating degradation factors in the operating conditions typical of the hybrid vehicles designed and developed in the project. Moreover, the design process and the real-time control of the HEV drivetrain, including the energy storage, rely on accurate estimations on battery degradation as a function of operating conditions and usage. With the focus set at vehicle durability, this state-of-health (SOH) estimation has become as important to the HEV as the estimation of state-of-charge (SOC) is for electric vehicles (EV). An accurate estimation of SOH ensures that the vehicle can maintain its performance over the designed lifetime and obtain the estimated reduction in fuel consumption.

Currently, the SOH estimation for industrial battery system is often based on laboratory measurements performed by the battery suppliers. Despite excellent precision, these measurements lack relevance to an HEV application since no standardized drive cycles exist. In other words, the results obtained after years of cycling a battery cell to a specific drive cycle is unlikely to be directly applicable to another drive pattern/application.

In SP3000, the electric energy storage system will be deeply analysed in different normal and extreme operating conditions. The experimental analyses on the two storage technologies will be carried out before using them on the demonstrators. All demonstrators will utilise battery modules from the same supplier, containing cells of the same type.

Lithium-ion module.

The distribution truck demonstrator may have an SC system, from one supplier and of one type, in addition to batteries in order to optimise the performance of the hybrid system.

Supercapacitor module.

The results of the SP3000 will be then functional to other Sub-projects (SP4000 and SP5000) in completing the design and installation work including the optimisation of the control strategy for the energy storage systems.


Involved partners and activities

AIT

  • Management of WP on safety testing
  • Test procedures development and models validation
  • Electrical and abuse testing activities on Li batteries and SC

ALTRA

  • Management of WP on vehicle and storage system specifications
  • Definition of energy storage specifications for planned demonstrators
  • Support to evaluation of control strategy

DIMAC

  • Test procedures development for SC
  • Supplier of SC cells and modules
  • Participation to SC design and modelling

ENEA

  • SP and WP Management on basic cell testing and modelling
  • Test procedures development and models validation
  • Basic testing activities on cells and modules of Li batteries and SC

Magna Steyr Battery systems

  • WP Management on module assembly and testing
  • Test procedure development
  • Delivery of the Li cells and modules

University of Pisa

  • Modelling and test procedure development
  • Basic testing activities on Li-ion and SC
  • Definition and validation of Li and SC models

Volvo

  • Storage system specifications for planned demonstrators
  • Test procedures development and models validation
  • Basic testing activities on Li cells and modules
Info master Last edited on 2014-11-14