The advantages of individual cell monitoring
So-called Cell Voltage Monitoring (CVM) systems are thus an important component of the corresponding test benches employed in car manufacturers' development departments. The standard procedure is to monitor the fuel cell stack as a complete system. This does however have certain disadvantages, as it does not permit the precise localisation of any faults occurring. Only with individual cell monitoring such as that provided by the MCM IntelliProbe system from SMART TESTSOLUTIONS is it possible to gain an in-depth insight into the situation inside the stack. Critical operating states are not just detected, they can also be accurately pinpointed.
An MCM IntelliProbe measurement system consists of up to 42 ten-channel
measurement modules, a link module and a bus termination tool.
It can also be extended to include the MCM Master
Module offering functions such as real-time local data processing.
Photo: SMART TESTSOLUTIONS
A CVM system has to satisfy a whole host of requirements. Stationary test bench applications demand a high level of measurement accuracy in combination with a high scanning rate. This permits detailed examination of how the systems react to changes of state, for example changes in load. Certain designers also expect an extended measuring range to allow the simulation of critical operating states which cause the cell voltages to drop into the negative range. A further important aspect in the development of fuel cell vehicles is the investigation of how the systems are affected by ambient conditions such as temperature and moisture. The monitoring technology employed must therefore be capable of supplying perfect results even at temperatures down to as low as -40°C and the electronics must be protected against the ingress of moisture.
The particular challenges of on-board use
The demands made of the monitoring technology are even