7718

7190

كارشناسي ارشد

الكترونيك

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1391

سيزده،108ص.: مصور،نمودار

ص.ع.به فارسي و انگليسي

احسان اديب

حسين فرزانه فرد

22/2/92

حميدرضا كارشناس، احمد قادري

مهندسي برق و كامپيوتر

ID7190

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

122 Improvement and implementation of three phase power factor correction converters Reza foroozeshfar r foroozeshfar@ec iut ac ir Date of Submission 2012 9 01 Department of Electrical and Computer Engineering IsfahanUniversity of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor ehsan adib e adib@cc iut ac ir Abstract Three phase AC DC power converters are vastly applied in industrial applications including adjustable speed drives uninterruptible power supplies battery energy storage systems electroplating welding units and inverters AC DC rectification is usually performed using diode or thyristor bridge rectifier with a large output capacitor This type of rectifier operates at low power factor and injects significant amount of harmonics into the power system Harmonics in the input current have many adverse effects such as distortion of input voltage increased conduction losses increased volt ampere rating of the power system equipment s error in metering and malfunctioning of utility relays and many other problems Six switch three phase rectifiers are one of the preferred topologies for implementation of active input current shaping in three phase AC DC converters This circuit suffers from high switching losses and severe problems due to reverse recovery of switches anti parallel diodes Several examples of soft switching auxiliary circuits for six switch boost converter are reviewed in this thesis In a method current harmonics are generated on the DC side of the diode bridge rectifier by a modulation circuit and then injected into the main using an injection circuit Modulation and injection circuits can be either passive or active which are fully reviewed Modular approach and three or four switch converters are other reviewed solutions to improve the power factor For fewer component count and simplified control and drive three phase PFC rectifier can be implemented using a converter with just one switch Single switch three phase PFC converters are divided into two categories of discontinuous voltage mode and discontinuous current mode converters that both are investigated In this thesis a solution is proposed to avoid discontinuous current at the input of the diode bridge rectifier Three switches and three high frequency transformers are applied to shape the input AC current especially at the zero voltage crossings Proposed rectifier operates at high switching frequencies and therefore the auxiliary circuit volume is low Also a new three phase power factor correction circuit base on DVM Cuk converter is introduced DVM Cuk converter has excellent power factor with very low harmonic content This is due to the fact that in this converter discharging mode of capacitor does not affect the input current Also a new single stage single switch soft switching three phase power factor correction converter is introduced The proposed discontinuous currentPDF created with pdfFactory trial version www pdffactory com

احسان اديب

حسين فرزانه فرد

حميدرضا كارشناس، احمد قادري