| 摘要 |
PURPOSE:To limit torque ripple to a low level over the entire control range by lagging the reference sine wave and reference triangular wave from a second inverter, by 1/12 of the wavelength of the reference sine wave, behind the reference sine wave and reference triangular wave having the frequency 3M times that of the reference sine wave from a first inverter. CONSTITUTION:In the case of N=15(M=5, N=3XM=15), reference sine wave and reference triangular wave from a second inverter are lagged, respectively, by 1/12 of the wavelength of the reference sine wave with respect to a first inverter 11, and a zigzag winding is applied onto the second output transformer 22 thus cancelling 17, 29, 31, 43th higher harmonics out of 13, 17, 29, 31, 43, 47, 59, 61th higher harmonics produced from the first and second inverters 11, 12. Consequently, even if the waveform is degenerated due to overmodulation at the time of high output voltage and 5th and 7th higher harmonics are produced, they are cancelled and torque ripple can be limited to a low level. |
