بررسي و تحليل عدم تعادل بار و ولتاژ شبكه در يكسو كننده وينا

چكيده انگليسي :

Analysis of Load and Grid Imbalance in a Vienna Rectifier Sayed Majid Hosseini Khorasgani majid hosseini@ec iut ac ir May 22 2017 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Dr Hamid Reza Karshenas karshen@cc iut ac irAbstract This thesis is concerned with Vienna rectifier performance under unbalanced loading and unbalanced gridvoltage conditions In order to ensure the widespread utilization of electrical transportation fast electric vehicle EV charging stations are required Due to the use of high power off board chargers Fast EV charging stationsare usually installed outside residential areas Accompanied with technological advancement dc microgridsare becoming an increasingly popular solution for many types of application such as fast EV charging stations Renewable energy sources and energy storage integration in fast EV charging stations will be achievablethrough dc microgrid implementation Different architectures can be assumed for a dc microgrid applied as afast EV charging station The bipolar single bus structure provides more flexibility and also offers more powertransfer capability while keeping the step down ratio of dc dc converters low In a fast EV charging station the central ac dc converter acts as a grid interface and supplying dc microgrid This converter plays an essentialrole in a fast EV charging station and enables sinusoidal input current shaping and regulation of the dc outputvoltage In this thesis a Vienna rectifier is employed as a central rectifier in a fast EV charging station withbipolar dc bus structure A Vienna rectifier is an advantageous power factor correction PFC rectifier whichis compatible with bipolar dc bus structure Considering bipolar dc bus structure different loading conditionmay lead to dc link voltage imbalance The goal of this work is to find suitable control and modulationapproaches for dc link voltage balancing Firstly topology operating principle analytic equation and three level space vector modulation for Vienna Rectifier are described Two predictive control methods i e deadbeatpredictive control and finite control set model predictive control FCS MPC are studied in details andcompared Simulation results are presented in order to show the performance of aforementioned controlmethods in achieving sinusoidal current shaping and output voltage regulation Due to the importance of dclink voltage imbalance caused by different load scenarios analytic expression for Vienna rectifier underunbalanced dc link voltage is derived Consequently dc link voltage balancing methods are presented for bothdeadbeat predictive control and FCS MPC Simulation results for the verification of these methods aredemonstrated Grid voltage unbalance is regarded as a power quality problem which may affect theperformance of three phase rectifiers Therefore in this thesis the effect of grid voltage unbalance on Viennarectifier operation is presented and analytic equation regarding this situation is introduced Then based on aninstantaneous power theory two compensation schemes for a Vienna rectifier system under grid voltageunbalance are proposed and verified by simulation results In this thesis experimental results obtained from alaboratory type setup are presented and compared with simulation results in order to validate the performanceof proposed control algorithms KeywordsDeadbeat Predictive Control FCS MPC Grid Voltage Unbalance Load Unbalance ViennaRectifier

حسيني خوراسگاني، مجيد

بررسي و تحليل عدم تعادل بار و ولتاژ شبكه در يكسو كننده وينا

عدم تعادل بار , عدم تعادل ولتاژ شبكه , كنترل پيش‌بين , deadbeat , كنترل پيش‌بين مدلي با حالت‌هاي متناهي , يكسوكننده وينا