| 摘要 |
PROBLEM TO BE SOLVED: To eliminate current irregularity and stabilize balance of a phase current by performing constant current control, by chopping only one switching element which is switched to on-state in the upper stage or the lower stage, out of a pair of upper and lower switching element groups for bipolar drive. SOLUTION: When arm chopping drive is performed with 4-phase excitation by bipolar pentagon drive, switching element groups of a drive circuit which are switched to on-state are two on the upper stage side (power source side) and one on the lower stage side (ground side), or one on the upper stage side and two on the lower stage side. One where the switching element out of the upper stage and the lower stage switched to on-state is one is selected, and constant current control is performed by chopping. The chopping system of an upper arm (power source side arm) and a lower arm (ground side arm) performs chopping at a point P1 where a current flows into windings and branches and at a point P2 where currents flowing through the windings gather. |
