In Electric Vehicles (EVs) efficient cell-to-cell balancing is essential to ensure functional safety during charging and discharging and to optimize battery capacity. Battery Management Systems (BMS) help to control the power input and output of battery cells, modules, and packs.
In conventional BMS, the communication between the battery components is based on galvanic isolated wired daisy chain communication. Wired harnessing is the current industry standard, but limits the design flexibility and increases the weight of the vehicle and the required manufacturing time.
In a wireless BMS (wBMS), each battery module is connected to a Battery Management Controller (BMC) through a Cell Monitoring Controller (CMC). The link is established either by a robust 2.4 GHz ISM band radio transceiver or by an Ultra-Wideband (UWB) communication channel, so no wired harnesses are required.
This wireless architecture brings several advantages:
- Weight & space savings – eliminating cables reduces both the vehicle’s weight and its occupied volume.
- Simplified integration – modules can be mounted, serviced, or swapped without disconnecting or re-routing wiring.
- Higher reliability – the system is less vulnerable to vibration induced wire fatigue and connector failures, which is critical in harsh automotive environments.
While the wBMS delivers clear benefits for space efficiency, assembly and serviceability, it also introduces new testing challenges that must be addressed:
- Rohde & Schwarz WBMS Test Solution
Rohde & Schwarz wBMS Test Solution
Automated test system, optimized for production lines
Rohde & Schwarz has developed together with major chipset suppliers ultra-compact automated test solutions for wBMS. With this test setup all the necessary wireless BMS module calibration, receiver, transmitter and DC tests can be conducted fast and executed reliably for verification in the lab and for production tests ensuring highest yield.
The test system consists of the R&S®CMP180Radio Communication Tester, the R&S®ExpressTSVP Universal Test and Measurement Platform, and the R&S WMT Wireless Automated Testing software framework. Over-the-air testing of the DUT is achieved in an interference free environment using an isolated chamber such as the R&S®CMQ200 shielded box.
Here you can download our uwBMS and wBMS flyer
Key features of the Rohde & Schwarz test solution
- R&S®ExpressTSVP cPCIe/PXIe-based modular instrument platform covering all non-RF wBMS interfaces and controlling the test bench including running the test automation software
- Parallel testing on up to 8x bidirectional RF ports of the R&S®CMP180 to further optimize asynchronous Tx and Rx tests and multi-module testing
- Complete crystal calibration & complete Tx/Rx tests
- R&S®CMQ RF shielded chambers with isolation of up to 80dB
- Python based R&S®WMT wireless test automation framework optimized for production testing with easy customizable GUI for sequencing and test plan creation
- Easy 1-button test execution and automated HTML report generation
Benefits
- Easy integration of solution due to the use of standard R&S instruments
- Shorter test times through very fast DC and RF tests by the R&S®ExpressTSVP in combination with the smart channeling function (multi-port / parallel testing) of the R&S®CMP180
- Reduced maintenance effort due to in-system self-test and in-system calibration capabilities of R&S modular instruments
- Dust protected, space and energy efficient with ultra-small footprint
- World-wide service based on local application engineering support and customizable service level agreements
The solution, built on Rohde & Schwarz’s proven test technology, delivers full coverage testing for every wBMS test case. It provides the speed and scalability needed to move efficiently from validation through to high volume production of even the most complex wBMS modules, whether they use narrow band 2.4 GHz ISM band or Ultra Wideband (UWB) communication.
To find out more, please get in contact with your local R&S representative.