The HIL battery bench - Questions to Joseph Martin and Philippe Pognant-Gros, IFPEN Engineers

The storage of electricity in batteries is a major challenge for the development of hybrid and electric vehicles. While these new powertrains undeniably offer a high level of environmental performance, their commercial success is largely dependent on their range.

		Questions to...
		Joseph Martin, R&D Engineer Battery test benches
		and
		Philippe Pognant-Gros, R&D Engineer Supervision of electrified transport systems

What is the background behind the HIL battery bench?

J. M. : The range of these new powertrains depends on both the chemical characteristics of the battery, the vehicle to be equipped and the conditions in which it is used. Hence there is a need for access to appropriate testing resources, such as the HIL battery bench that IFP Energies nouvelles acquired in 2010.

IFP Energies nouvelles has been studying the storage of electricity in batteries since 2006. It is one of the technological building blocks essential to the development of hybrid and electrical vehicles. We first developed a standard test bench, of the type used in industry, in order to study different battery cells and model their behavior. We very quickly realized that we needed to acquire testing resources that would also enable us to test the onboard electronic system controlling the battery, the BMS - Battery Management System.

To do this, we used a tool already developed by IFP Energies nouvelles to study IC engines: the ACEbox^© control system, which includes all the essential software components to quickly prototype the control laws. It is this box that enabled us to have the bench communicate with the BMS and to estimate the charge status of the battery in real-time.

The last stage consisted in simulating a complete hybrid architecture to test the battery in real conditions of use without needing to develop a real vehicle. This was made possible by HIL -Hardware in the Loop - technology, also mastered by IFP Energies nouvelles. The HIL battery bench was thus born and it has been operational since mid-2010.

What type of tests is the HIL battery bench intended for?

P. P.-G. : Our studies focusing on batteries are mainly conducted as part of demonstrator vehicle projects, run either alone or with partners. But none of these projects had access to a single tool for characterization of battery cells or design of BMS functionalities, for example.

Thanks to the HIL battery bench, we can now test different battery chemistries aimed at a variety of vehicles - light vehicles, trucks, buses, etc. - with the same bench. All that is required is to simulate the vehicle architecture and driving cycle - braking, hill, traffic jam, etc. - by intervening on the software part of the bench. The only physical element required is the battery, or a simple battery cell.

We have already used this bench to test the battery for the FlexHybrid, the laboratory rechargeable hybrid vehicle developed by IFP Energies nouvelles. The HIL system will also be used as part of the Melodys project launched in 2010 and coordinated by Renault Trucks. Finally, it will also be used to test energy supervision calculators, for functionalities linked to the battery.

Industrial players are showing a lot of interest in the HIL battery bench, which represents a decision-making tool that could help them select and dimension the batteries of their future vehicles. The result would be savings in both development and production costs.

+ Industrial development > Engines