| 摘要 |
PROBLEM TO BE SOLVED: To reduce voltage ripple caused by charge/discharge during a switching term in a multilevel power conversion device.SOLUTION: In a voltage command prohibition zone calculation part 1, information V_prohi_p and V_prohi_n on a voltage command prohibition zone of a phase voltage command value Vin which a flying capacitor Cbecomes equal to or higher than a voltage fluctuation amount allowable value Vis predicted from a phase current detection value (instantaneous value) I, a switching term Tand a flying capacitor capacity C by calculation. In a single-phase offset amount calculation part 2, the voltage fluctuation ripple of the flying capacitor Cis suppressed equal to or less than a specific value by adding offset to the voltage command value Vin such a manner that the phase voltage command value Vis not included in the voltage command prohibition zone. A voltage error that is generated by offset is corrected in the next and subsequent switching terms.SELECTED DRAWING: Figure 1 |
