The housings of HV batteries not only serve to protect the battery cells and electronics inside them, but are also a structural part of the vehicle frame. Mechanical loads must be measured for an optimal housing design - inside and on the outside of the housing. This example shows how the necessary measurements are made easily and safely with strain gauges and strain gauges measurement modules.
Housings protect HV batteries in electric vehicles from dirt, dust and moisture, thereby ensuring proper operation and safety for vehicle passengers. In addition to the protective function for the battery, the housing is also increasingly taking on structural tasks as a load-bearing element in the vehicle frame.
The housing is often made of steel, aluminum and plastic or a mixture of these materials and must be designed to be as light as possible with a high load capacity. For the optimum material design of the housing, the various mechanical loads acting on the housing must be taken into account.
The housing must be able to withstand these stresses in any situation and must not break in order not to jeopardize the safety and proper operation of the battery.
Measurement of mechanical strains and stresses in a HV battery housing for optimal material design.
Strain gauges are used to measure strains and stresses on the inside and outside of the housing. For this purpose, the strain gauges will be applied as individual strain gauges and as rosettes. The measurements are to be carried out in road tests in order to obtain realistic load profiles.
For the measurements inside the housing, the necessary measurement technology must ensure HV safety.
The measurement range of the measurement modules must be adaptable to the specific material properties (aluminum, steel, plastic) and the expected size (e.g. ±1,000 µm/m).
It should be possible to adjust the measurement range and the supply voltage in the measurement module even after the strain gauges have been installed, so that smaller or higher strain values than initially expected can be acquired. And this without an additional calibration of the strain value.
Since strain often has to be correlated with other measurement variables, such as temperatures or accelerations, it should be possible to easily expand the measurement system with appropriate measurement modules.
Measurement modules from the Vector CSM E-Mobility Measurement System are used to accurately analyze the strains and stresses inside and outside the battery housing.
With this measurement technology solution, the mechanical strains inside and outside the battery housing can be measured. Due to the robust and compact design of the measurement modules, the measurement can also be carried out in road tests.
Other measurement modules can also be connected via the XCP-Gateway and their data acquired synchronously. For example, temperatures in the battery cells can be measured in parallel and included in the analysis.
Here you find the complete application report for download as PDF.
Type HV STG4 pro BS20
EtherCAT®-based measurement module for distributed use under demanding conditions in the high-voltage environment: robust, extremely compact and each with 4 time-synchronous strain gauge inputs.
XCP-Gateway is the interface between the data acquisition software (e. g. vMeasure, CANape®, INCA®, Vision® ...) and the EtherCAT® measurement modules from CSM. It includes an EtherCAT® master and an XCP-on-Ethernet slave.
CSM’s EtherCAT®-based ECAT STGMM 6 with six time-synchronous strain gauge channels for quarter-, half- and full bridges has been designed for precise and synchronous acquisition of mechanical strain directly at the strain gauge measurement points.
Electromobility continues to gain momentum. Various energy storage, drive and charging systems pave the way to electric mobility. The development of high-voltage batteries, inverters and electric motors places high demands on measurement technology in order to obtain the right results for further optimization. Together with Vector Informatik, CSM has developed a measurement system that leaves nothing to be desired.
Swift configuration of measurement chains: CSMconfig is the reliable configuration software for all CAN and EtherCAT® based measurement modules from CSM. The clearly arranged and easy-to-use user interface allows an easy setting of all measurement parameters. This helps speeding up the measurement setup considerably.
vMeasure exp, developed by Vector Informatik, is an easy-to-use software tool for the acquisition and analysis of measurement data that can be used in combination with all CAN- and EtherCAT®-based CSM measurement modules. CSMconfig was integrated directly to ensure swift configuration.