| 摘要 |
PROBLEM TO BE SOLVED: To control a voltage difference between bus capacitors without providing an additional circuit or the like and stop the operation by detecting an error without adverse effects on an inverter even if such voltage difference is generated between bus capacitors. SOLUTION: When a voltage difference is generated between bus capacitors 3a, 3b, a DC current compensation circuit 14 outputs a DC current compensating value depending on the voltage difference, and an inverter controls a voltage including a fine DC element which causes the generation of a voltage difference between bus capacitors 3a, 3b by applying this DC current compensation value to a DC element control circuit 12. Moreover, when the voltage difference between the bus capacitors 3a, 3b exceeds the predetermined rate of the total voltage of bus capacitors 3a, 3b, a bus capacitor voltage failure detecting circuit 15 determines the generation of a failure. |
