4731

4450

كارشناسي ارشد

قدرت

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1388

نه،97،[I] ص.: مصور، جدول،نمودار

ص.ع.به فارسي و انگليسي

محمد مدني، اكبر ابراهيمي

حسين فرزانه فرد

88/8/11

حميدرضا كارشناس، مهدي معلم

مهندسي برق و كامپيوتر

ID4450

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Design and implementation of a soft switching inverter for BLDC motor drive Mohammad Mahdi Shahbazi mmshahbazi@ec iut ac ir 2009 05 10 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan Iran 84156 83111 Degree M Sc Language FarsiSupervisors S M Madani madani104@yahoo com A Ebrahimi ebrahimi@cc iut ac irAbstractBrushless Direct Current BLDC machine is a kind of permanent magnet AC machine and is named thisway because of many similarities with DC machine The structure and design of this machine is verysimilar to the permanent magnet synchronous machine PMSM One of the differences between these twokinds of machines is their stator winding induced voltage versus electrical angle Therefore this machine isalso called trapezoidal permanent magnet ac machine Due to its high torque per volume ratio maintenancefree low inertia and ease of heat exchange new applications for this machine type are coming along So improving the drive circuit of this machine in parallel with expansion of its application is of engineers interest One of the performance improvement methods for this drive is reducing the switching losses and itsinverter electro magnetic interference without major extra costs To achieve this goal employing soft switching techniques for inverter is an appropriate option In soft switching techniques by addingauxiliary circuits to inverter main circuit voltage and current change incidence can be significantlyreduced and switching losses are almost eliminated Improving power quality characteristic of systeminput side and lowering costs are other fields of interest In this thesis first three phase brushless DC machine and its operational principles are introduced Then other types of this machine with their basic drive methods are described Then by using a classificationmethod the ruling principles of soft switching inverters are presented After that some topology exampleswith special capabilities and their operation methods are presented The aim of this thesis is presenting a soft switching topology with fewer elements compared to otherpresented soft switching inverters So in chapter five such a topology with its drive method is proposed Then the proposed topology is analyzed by explaining its operating principle and its drive method Thus byexplanation of the design method a prototype of the proposed topology in accordance with an availablemotor is designed By explaining the simulation method and elements modeling used in simulatorprogram the proposed topology is simulated and simulation results are presented A digital signalprocessor is used for the implementation of this inverter This processor computes instantaneous speed andrealize control loop Also the processor generate control signal by receive and analyzing of hall effectsensors data For final implementation of this topology signal shaper circuits and gate drive for powerswitches are designed and implemented Finally experimental results of implemented topology are shown and which are quite closed to the expected ones The thesis is ended by concluding the results and makingsome suggestions for future works Key Words Brushless DC motor soft switching inverter resonant pole inverter zero voltageswitching

محمد مدني، اكبر ابراهيمي

حسين فرزانه فرد

حميدرضا كارشناس، مهدي معلم