بررسي اثرات مخرب ولتاژهاي سوييچينگ بر روي موتورهاي القايي متصل به كابل تغذيه شونده با اينورتر PWM و روش هاي جبران آن

چكيده انگليسي :

90 Analysis of switching voltage destructive effects on PWM inverter fed induction motors with long connection cables and mitigation methods Majid Rostami Najafabadi Majidrostami2008@gmail com September 15 2014 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M SC Language FarsiProfessor Mehdi Moallem moallem@cc iut ac irabstractWith the development of power electronic device today using the swiching feeding sourcesfor feeding andcontrolling induction motorshas becom a common matter Switching voltages resulting from this feedingsource have destructive effects on winding insulation in induction motors Among these effects we can namethe nonsymetric distribution of voltage on the winding in the initial moments of imposing voltage Also dueto physical and invironmental reasons in practical applications the cable is used as a feeding mediatorbetween the motor and the swiching feeding souece so that it leads to voltage overshot in the motor terminal The aim of this study is to investigate these destructive effects and the alternatives to compensating for it In this study first the system under consideration has been fully described an then some of each of the partsin the system Then the existing models for induction motors and cables have been investigate in highfrequencies and taking the advantages and defeets of each one and the aim of the study into consideration themost suitable model has been chosen for simulation Then simulating system the destructive effects ofswitching voltages on induction motors and the effect of each of the parameters in the system has beeninvestigated Among the sensivites analysis performed we can name the sensivity analysis relativeproportionalto th cable length and the rising time for output pulses in the inverter and harmonics Also forthe purpose of studying of voltage distribution in the stator winding the extended model for induction motorhas been used In this stage using the sensivity analysis the way that voltage distribution is changedproportional to different parameters of the system including cable length and rise time has been investigated Comparing the result of performed simulations with existing application standards using the compensationtechniques for system seemed to be a must Among the most common techniques we can name filter Within a general grouping we can devide the filterused for this system to the filters located in the motor terminal and filters located in the inverter output Atthe last part of this study the performance principles for each filter has been investigated and the existingdifferent typology and the way they are designed have been studied and performing simulations the effect ofeach filter on the motor terminal voltage and voltage distribution on stator winding has been studied At lastdue to the many times the Iranian workmens have been faced with this matter and the need to the existence ofa systematic method to solve this problem an algorithm for studying the destructive effects and providing thecompensation techniques has been stated on this study Key WordsHigh frequency modeling impedance measurement overvoltage transients Cable modeling

رستمي نجف آبادي، مجيد

بررسي اثرات مخرب ولتاژهاي سوييچينگ بر روي موتورهاي القايي متصل به كابل تغذيه شونده با اينورتر PWM و روش هاي جبران آن

مدل ساز ي فركانس , اندازه گيري امپدانس , اضافه ولتاژهاي گذرا