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Three Phase to Neutral Full Wave Regulated Rectification

IP.com Disclosure Number: IPCOM000078625D
Original Publication Date: 1973-Feb-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Hoffman, HS: AUTHOR

Abstract

A reduced voltage output can be obtained by using line to neutral peak rectified voltage from a three-phase line. This system will provide either unregulated peak voltage or regulated voltage from peak to 50% of peak, without having DC in the neutral due to half-wave rectification. Choke 10 in the neutral line limits surge currents, but is not necessary to the principles of this system. Although switching devices 12, 14 are shown as thyristors, any switch with appropriate ratings can be used. In another variation, diodes 16, 18, 20, 22, 24, 26 in the three-phase bridge could be replaced with switches, and switches 12, 14 could be eliminated.

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Three Phase to Neutral Full Wave Regulated Rectification

A reduced voltage output can be obtained by using line to neutral peak rectified voltage from a three-phase line. This system will provide either unregulated peak voltage or regulated voltage from peak to 50% of peak, without having DC in the neutral due to half-wave rectification. Choke 10 in the neutral line limits surge currents, but is not necessary to the principles of this system. Although switching devices 12, 14 are shown as thyristors, any switch with appropriate ratings can be used. In another variation, diodes 16, 18, 20, 22, 24, 26 in the three-phase bridge could be replaced with switches, and switches 12, 14 could be eliminated.

Assume one of the phase to neutral voltages 28 to N is at + peak and peak voltage value is desired. The path will be from this phase line through its + diode 16 and the + thyristor 12, to the + side of output capacitor 30 and/or load terminal
32. The return path is from the - of the output capacitor and/or load terminal 34, through + diode 36 and choke 10 to neutral. One-sixth of a cycle later another line 38 will be at - peak, and the path will be from N through 10 and - diode 40 to the + side of 30 and/or 32, returning through 14 and 24 to 38.

Thyristors 12 and 14 are never on together. They are turned off by the input voltage falling below the output voltage and thus back biasing them. The possible on time lies between 90 degrees and 150 degrees of the individual hal...