The Research Of Testing System For DC/DC Converter In Fuel Cell Electric Vehicle Based On Virtual Instrument

The development of Fuel Cell Electric Vehicle (FCEV) becomes the new focus of Automobile Industry. DC/DC converter, one of the most important parts of the power system of FCEV, demands lots of bench tests to acquire the parameters matching with the FCEV. This thesis is focused on the research of the automatic testing system for DC/DC Converter in FCEV, and the virtual instrument testing structure is built based on the PXI modular hardware and LabVIEW application software environment.At first, the principle and specialty of the power system of FCEV and Buck DC/DC converter is introduced.The topology of DC/DC converter testing system is designed according to the bench test requirements. The fundamentals and structure of virtual instrumentation and PXI bus are discussed detailedly. With the system configuration option, the whole system is devided into electrical parameters, environmental parmeters and the controller parameters sub-system independently.Secondly, the selection of voltage, current and temperature transducer and relative signal conditioning circuits is analyzed. The CAN bus communication network in FCEV is also introduced, and the CAN interface card is applied to simulate the vehicle system controller node. Futhermore, the Electromagnetic Compatibility (EMC) of testiong system is decribed, which includes the configuration of the analog input of Data Acquisition Card (DAQ) for the integrity of sinal and the measues taken to deal with the Electromagnetic inference.Finally in the light of modular software programming, the thesis presents the software integration of the data, function and user interface from different testing systems. The Kaiser widow FIR digital filter is also designed based on LabVIEW, and the results is testified by MATLAB. The DAQmx driver of DAQ and the DLL driver of CAN interface card is encapsulated and called in LabVIEW, thus the independent sub-testing system application could be set up correspondingly.The debugging of the testing system is excecuted in the DC/DC converter bench testing environment. The experimental data demonstrates that the resolution, which is flexible, expandable and general, successfully meets the precision standard and expecting testing requirements.