Study on Generation of Harmonic Voltage using Synchronous Machine with d-axis and q-axis Harmonic Field Windings

Abstract

-We examined the generation of harmonic voltage by a synchronous machine adding d-axis and q-axis harmonic field windings in order to reduce the harmonics in a power line. We derived the expressions of the armature voltage in the case of supplying the currents with the frequency nf to the d-axis and q-axis harmonic field windings. We constructed the synchronous machine adding the harmonic windings. In this paper, the expressions and the experimental results on the generation of harmonic voltages by the synchronous machine are presented.

Study on Generation of Harmonic Voltage using Synchronous Machine with d- and q-axis Harmonic Field Windings - Part 2

“…In this section, the values calculated from the theoretical expressions [7] of harmonic voltages in armature winding are compared with the values obtained by the experiment in the previous section.…”

“…The power spectrum and the waveforms of the harmonics in the armature voltage were measured in the case of supplying the AC currents with frequency 6 f to the harmonic field windings of the experimental synchronous machine. Moreover, the values calculated from the theoretical expressions [7] Fig. 1.…”

“…The structure of this experimental synchronous machine is different from that of a usual synchronous machine and the experimental machine has both d-axis and q-axis field windings. In the previous paper [7], the power spectrum of the armature voltage was measured in the case of supplying AC currents with frequency 6 f ( f : frequency of the power line) to the harmonic field windings of the experimental synchronous machine. An AC voltage with frequency 6 f generated by an oscillator was used.…”

Space harmonics of synchronous machines calculated by finite element method

“…Harmonics influence on design, operation and control of synchronous machines have been an on-going research topic for decades [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. There are two types of harmonics related to synchronous machines: time harmonics [1][2][3][4][5][6][7][8] and space harmonics [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

“…There are two types of harmonics related to synchronous machines: time harmonics [1][2][3][4][5][6][7][8] and space harmonics [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Time harmonics are generated by power electronics devices in power systems [5], which could cause issues such as eddy-current losses [3,5] and interference with voltage regulation [4] of synchronous machines.…”