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| The '''Vienna Rectifier''' is a [[pulse-width modulation]] rectifier, invented in 1993 by Prof. Johann W. Kolar.<ref>J. W. Kolar, „Dreiphasen-Dreipunkt-Pulsgleichrichter“, filed Dec. 23, 1993, File No.: A2612/93, European Patent Appl.: EP 94 120 245.9-1242 entitled “Vorrichtung und Verfahren zur Umformung von Drehstrom in Gleichstrom”.</ref> It provides:
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| * [[Three-phase]] three-level three-switch PWM [[rectifier]] with controlled output voltage.<ref>J. W. Kolar, F. C. Zach, “A Novel Three-Phase Utility Interface Minimizing Line Current Harmonics of High-Power Telecommunications Rectifier Modules”, Record of the 16th IEEE International Telecommunications Energy Conference, Vancouver, Canada, Oct. 30 - Nov. 3, pp. 367-374 (1994).</ref>
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| * Three-wire input, no connection to neutral.
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| * Ohmic mains behaviour {{Citation needed|date=June 2009}}
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| * Boost system (continuous input current).
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| * Unidirectional power flow.<ref>J. W. Kolar, H. Ertl, F. C. Zach, “Design and Experimental Investigation of a Three-Phase High Power Density High Efficiency Unity Power Factor PWM (Vienna) Rectifier Employing a Novel Integrated Power Semiconductor Module”, Proceedings of the 11th IEEE Applied Power Electronics Conference, San Jose (CA), USA, March 3–7, Vol.2, pp.514-523 (1998).</ref>
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| * High power density.
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| * Low conducted common-mode EMI emissions.
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| * Simple control to stabilize the neutral point potential.<ref>J. W. Kolar, U. Drofenik, F. C. Zach, “Space Vector Based Analysis of the Variation and Control of the Neutral Point Potential of Hysteresis Current Controlled Three-Phase/Switch/Level PWM Rectifier Systems”, Proceedings of the International Conference on Power Electronics and Drive Systems, Singapore, Feb.21-24, Vol.1, pp.22-33 (1995).</ref>
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| * Low complexity, low realization effort <ref>J. W. Kolar, H. Ertl, F. C. Zach, “Design and Experimental Investigation of a Three-Phase High Power Density High Efficiency Unity Power Factor PWM (Vienna) Rectifier Employing a Novel Integrated Power Semiconductor Module”, Proceedings of the 11th IEEE Applied Power Electronics Conference, San Jose (CA), USA, March 3–7, Vol.2, pp.514-523 (1998).</ref>
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| * Low switching losses.<ref>*Report “How to Design a 10kW Three-Phase AC/DC Interface Step by Step” at [http://www.gecko-research.com/downloadFreeTrial/FrontEndComparison_Part_1.html www.gecko-research.com]</ref>
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| * Reliable behaviour (guaranteeing ohmic mains behaviour) under heavily unbalanced mains voltages and in case of mains failure.<ref>J. W. Kolar, U. Drofenik, F. C. Zach, “Current Handling Capability of the Neutral Point of a Three-Phase/Switch/Level Boost-Type PWM (Vienna) Rectifier”, Proceedings of the 27th IEEE Power Electronics Specialists Conference, Baveno, Italy, June 24–27, Vol.II, pp.1329-1336 (1996).</ref>
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| ==Topology==
| | If you are looking for a specific plugin, then you can just search for the name of the plugin. Online available for hiring are most qualified, well knowledgeable and talented Wordpress developer India from offshore Wordpress development services company. Change the site's theme and you have essentially changed the site's personality. If you need a special plugin for your website , there are thousands of plugins that can be used to meet those needs. In the most current edition you can customize your retailer layout and display hues and fonts similar to your site or blog. <br><br>Choosing what kind of links you'll be using is a ctitical aspect of any linkwheel strategy, especially since there are several different types of links that are assessed by search engines. Best of all, you can still have all the functionality that you desire when you use the Word - Press platform. Well Managed Administration The Word - Press can easily absorb the high numbers of traffic by controlling the server load to make sure that the site works properly. From my very own experiences, I will let you know why you should choose WPZOOM Live journal templates. By using Word - Press, you can develop very rich, user-friendly and full-functional website. <br><br>But before choosing any one of these, let's compare between the two. Word - Press has different exciting features including a plug-in architecture with a templating system. all the necessary planning and steps of conversion is carried out in this phase, such as splitting, slicing, CSS code, adding images, header footer etc. Thousands of plugins are available in Word - Press plugin's library which makes the task of selecting right set of plugins for your website a very tedious task. Converting HTML to Word - Press theme for your website can allow you to enjoy the varied Word - Press features that aid in consistent growth your online business. <br><br>If all else fails, please leave a comment on this post with the issue(s) you're having and help will be on the way. In case you need to hire PHP developers or hire Offshore Code - Igniter development services or you are looking for Word - Press development experts then Mindfire Solutions would be the right choice for a Software Development partner. This allows for keeping the content editing toolbar in place at all times no matter how far down the page is scrolled. Can you imagine where you would be now if someone in your family bought an original painting from van Gogh during his lifetime. Digital digital cameras now function gray-scale configurations which allow expert photographers to catch images only in black and white. <br><br>Millions of individuals and organizations are now successfully using this tool throughout the world. I don't want that for my visitors and I'm quite sure they don't either. When you beloved this informative article and you wish to obtain more details regarding [http://miniURL.fouiner.info/wordpress_dropbox_backup_447905 wordpress backup] i implore you to visit our web-page. However, there are a few other Wordpress plugins also for its development which requires adding files in your Wordpress setup. Working with a Word - Press blog and the appropriate cost-free Word - Press theme, you can get a professional internet site up and published in no time at all. Article Source: Hostgator discount coupons for your Wordpress site here. |
| [[Image:Vienna rectifier schematic.jpg|thumb|150px|Fig. 1: Schematic of a Vienna Rectifier.]]
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| The Vienna Rectifier is a unidirectional three-phase three-switch three-level [[Pulse-width modulation]] (PWM) rectifier. It can be seen as a three-phase [[diode bridge]] with an integrated boost converter.
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| ==Applications==
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| [[Image:Vienna rectifier real.jpg|thumb|200px|Fig. 2: Top and bottom views of an air-cooled 10kW-Vienna Rectifier (400kHz PWM).]]
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| The Vienna Rectifier is useful wherever six-switch converters are used for achieving sinusoidal mains current and controlled output voltage, when no energy feedback from the load into the mains is required. In practice, use of the Vienna Rectifier is advantageous when space is at a sufficient premium to justify the additional hardware cost. These include:
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| * Telecommunications power supplies.
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| * [[Uninterruptable power supply|Uninterruptable power supplies]].
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| * Input stages of AC-drive converter systems.
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| Figure 2 shows the top and bottom views of an air-cooled 10 kW-Vienna Rectifier (400 kHz PWM), with sinusoidal input current s and controlled output voltage. Dimensions are 250mm x 120mm x 40mm, resulting in a power density of 8.5 kW/dm3. The total weight of the converter is 2.1 kg <ref>S. D. Round, P. Karutz, M. L. Heldwein, J. W. Kolar, “Towards a 30 kW/liter, Three-Phase Unity Power Factor Rectifier”, Proceedings of the 4th Power Conversion Conference (PCC'07), Nagoya, Japan, April 2–5, CD-ROM, ISBN 1-4244-0844-X, (2007).</ref>
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| ==Current and voltage waveforms==
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| [[Image:vr wave.jpg|thumb|200px|Fig 3:Time variation of voltage-phases ua, ub, uc of the current-phases ia, ib, ic.
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| Fig. 2: From top to bottom: 1) mains voltages ua, ub, uc. 2) mains currents ia, ib, ic. 3) rectifier voltage at uDaM (see Fig. 1), which forms the input current. 4. Midpoint current of the output capacitors (i0 in Fig. 1). 5. Voltage between mains midpoint M and the output voltage midpoint 0. Note: Inner mains inductance is not considered, and therefore the voltage across the [[filter capacitor]]s is therefore equal to the mains voltage.]]
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| Figure 3 shows the system behavior, calculated using the power-electronics circuit simulator.<ref>[http://www.gecko-research.com www.gecko-research.com]</ref> Between the output voltage midpoint (0) and the mains midpoint (M) the common mode voltage u0M appears, as is characteristic in three-phase converter systems.
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| ==Current control and balance of the neutral point at the DC-side==
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| It is possible to separately control the input current shape in each branch of the diode bridge by inserting a bidirectional switch into the node, as shown in Figure 3. The switch Ta controls the current by controlling the magnetization of the inductor. Switched on charges the inductor which drives the current through the bidirectional switch. Deactivating the switch increases causes the current to bypass the switch and flow through the freewheeling diodes Da+ and Da-. This results in a negative voltage across the inductor and drains it. This demonstrates the ability of the topology to control the current in phase with the mains voltage ([[Power factor correction|PFC]] capability).
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| To generate a sinusoidal power input which is in phase with the voltage
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| <math> \underline{i}_D = G \star \underline{u}_C \approx G \star \underline{u}_1</math> | |
| the average voltage space vector over a pulse-period must satisfy:
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| <math> \underline{u}_D\star = \underline{u}-j\omega_1L_1\underline{1}_D</math>
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| For high switching frequencies or low inductivities we require (<math>L1</math>) <math>\underline{u}_D \star \approx \underline{u}_1</math>.
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| The available voltage space vectors required for the input voltage are defined by the switching states(sa,sb,sc) and the direction of the phase currents. For example, for <math>iDa>0,iDb,iDc<0</math>, i.e. for the phase-range<math> \phi_1 = -30^\circ...+30^\circ</math> of the period(<math>\phi_1</math>) the phase of the input current space vector is <math>i_D \approx i_1</math>). Fig. 4 shows the conduction states of the system, and from this we get the input space vectors shows in Fig. 5 <ref>iPES (Interactive Power Electronics Seminar): Java-Applet Animation of the Vienna Rectifier at [http://www.ipes.ethz.ch/ipes/2002Vienna1/vr1.html www.ipes.ee.ethz.ch]</ref>
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| [[Image:Conduction states vr.jpg|thumb|400px|Fig 5: Conduction states of the Vienna Rectifier, for ia>0, ib,ic<0, valid in a <math> 60^o</math> sector of the period T1
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| sa,sb, and sc characterise the switching state of the system. The arrows represent the physical direction and value of the current midpoint i0.]]
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| ==References==
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| {{Reflist}}
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| [[Category:Electronic circuits]]
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| [[Category:Electrical power conversion]]
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| [[Category:Power electronics]]
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