Research On Measurement And Experiment Management Of Variable Frequency AC Power System

Compared to constant frequency ac power,variable frequency(360Hz~800Hz)ac power which has large capacity,simple structure small volume weight and can realize the starting generator,is a considering solution for more electric aircraft power system.As a representative of MEA in civil aviation field,B787 uses VF ac power system,for 230/400 V voltage class.Because of too many secondary power conversion devices and complex structure of power system,in order to meet the demand of airborne equipment,how to accurately analyze electric parameters characteristics of VF power system,and realize effective management of system history experimental data are practical problems.Therefore,a general automatic test system is developed based on VF power system.The thesis firstly analyzes the research status about the technology in aircraft electrical power system testing and experiment management at home and abroad,combined with test standards such as MIL-STD-704 F and GJB 5189-2003 summarizes the testing difficulties about RMS,distortion spectrum of VF characteristics and the existing shortage of power system database management is put forward.When the sampling rate is fixed,the frequency fluctuation will reduce testing accuracy of voltage RMS;the existence of harmonic and inter-harmonic make spectrum leakage and fence effect based on FFT algorithm analysis.At the same time,the existing data management technology which is simple and inefficient,cannot meet requirements for testing of VF ac power system.For the difficulties of testing and deficiencies of database management,combined with the project requirements,the thesis put forward the general principles of hardware selection and designed a data acquisition system based on PXIe bus,analysis the output precision of VF conditioning circuit.Combining with the C language to write the VF electricity parameter analysis and database management software based on LabVIEW.Choose RMS algorithm,using cosine window to restrain spectrum leakage,and interpolation algorithm to eliminate the fence effect;TDMS format was chosen as the large capacity data record format text in VF database management,method of analog data storage based on time,there is a one-to-one correspondence between store the data form and TDMS logical structure,digital storage based on system time,recording in the form of Excel spreadsheets.The soft hardware of test system had been through the acceptance and put into service,it produced good economic benefit and scientific results.