| 摘要 |
PURPOSE:To eliminate the need for a high voltage transformer for a higher harmonic compensator by synthesizing an output from a first current transformer and an output from a Y-DELTA current transformer for converting current phase. CONSTITUTION:Outputs from first current transformers 11, 12 and an output from a Y-DELTA current tranformer 16 for converting current phase are synthesized by resistors 21, 22, thus including no higher-harmonic voltage value of a (6n+ or -1) harmonic, where n represents an odd number, in detecting voltage values VGU, VGV. That is, higher harmonic currents mutually denied by an in-phase transformer 2 and a DELTA-Y transformer 3 can be removed previously from a compensation command value. Consequently, power supply currents iSU-iSW can be formed in a since wave shape without using a high-voltage receiving transformer by operating a higher harmonic compensator 7 connected in parallel with the secondary side of the in-phase transformer 2 together with the first current transformers 11, 12 on the basis of detecting voltage values VGU, VGV. Accordingly, a high voltage transformer for the higher harmonic compensator 7 can be omitted. |
