A NOVEL 3-PHASE TO 5-PHASE TRANSFORMATION USING a SPECIAL TRANSFORMER CONNECTION By Mr.S.SURESH KUMAR (09A91A0241) Mr.P.SAI SANDEEP (09A91A0237) Mr.B.BHARATH REDDY (09A91A0209) Mr.A.AVINASH (09A91A0203) Under The Guidance of Mr.R.S.Sudhakar

CONTENTS: Introduction Phase conversion Special transformer Phasor diagram conclusion:

Introduction: Multi phases are actually using in induction motors. In the past for the process of phase conversion power semi conductors are used to produce phase shifting mechanism. because of their less cost .But due to these power electronic devices there is a chance for the occurrence of harmonics, repulsions and switching losses. As a result it leads to the unsatisfactory results. For the process of loss less performance we designed a special transformer connection that converts a 3-phase input to 5- phase output .The even phases like 6,12,18..etc., are the multiples of 3 and they can be obtained by suitable adjustments. but the odd phases like 5,7,9,11 can not be obtained in that way. our special transformer connection can make it possible.

Phase conversion Converts 3-phase to 5-phase. We have obtain with 5-phase supply of constant Voltage and constant frequency. Bulk voltage is obtained. Scope to generate bulk power. Induction machines works with multi phase will suffer with less harmonics.

Special transformer Possible connections: 1) Input star, output star 2) Input star, output polygon 3) Input delta, output star 4) Input delta, output polygon Here the proposed transformer is Input star, output star type. Six terminals of primaries are connected in an appropriate manner resulting in star and/or delta connections and the 16 terminals of secondaries are connected in a different fashion resulting in star or polygon output

WINDING ARRANGEMENT FOR FIVE-PHASE STAR OUTPUT Three separate cores are designed with each carrying one primary and three secondary coils, except in one core where only two secondary coils are used. Six terminals of primaries are connected in an appropriate manner resulting in star and/or delta connections and the 16 terminals of secondaries are connected in a different fashion resulting in star or polygon output. The connection scheme of secondary windings to obtain a star output is illustrated in Fig and the corresponding phasor diagram is illustrated in Fig

The input phases are designated with letters “X” “Y”, and “Z” and the output are designated with letters “A”, “B”, “C”,“D”, and “E”. As illustrated in Fig, the output phase “A” is along the input phase “X”. The output phase “B” results from the phasor sum of winding voltage “ c6 c5” and “b1b2 ”, the output phase “C” is obtained by the phasor sum of winding voltages “a4a3 ” and “b3b4 ”. The output phase “D” is obtained by the phasor addition of winding voltages “ a4a3” and “c1c2 ”and similarly output phase “E” results from the phasor sum of the winding voltages “c3c4 ” and “b6b5 ”. In this way, five phases are obtained.

Phasor diagram In the phasor diagram below the input phases are displaced by a phase shift of 120 degrees . Whereas, in case of 5-phase output the phase voltages are displaced by a phase shift of 72 degrees. In the adjacent phasor diagram Vx and Va are the reference phasors .

conclusion: so by designing this special transformer connection and taking suitable input- output connection pattern the three-phase grid power can be coverted to a five-phase output supply. and can be used in drives applications and may also be further explored to be utilized in multi phase power transmission systems.