| 摘要 |
PROBLEM TO BE SOLVED: To enhance the control accuracy of an AC output voltage even when the DC voltage is varied, while suppressing imbalance of the waveform due to offset on the AC output voltage.SOLUTION: Three spatial vectors V1, V7, V8 surrounding a control voltage command Vref are selected. Based on the detection values Vdc1, Vdc2 of respective DC voltages and the three spatial vectors V1, V7, V8, α-&bgr; coordinate of three dynamic spatial vectors V1, V7, V8 is calculated. Based on the α-&bgr; coordinate of respective dynamic spatial vectors V1, V7, V8 and the α-&bgr; coordinate of the control voltage command Vref, and the carrier period Ts, the output times t0, ta, tb of respective dynamic spatial vectors are calculated. The gate signal of a switching element is generated by the dynamic spatial vectors V1, V7, V8 and the output times t0, ta, tb thereof.SELECTED DRAWING: Figure 8 |
